national sample, it is important to acknowledge a few
methodological limitations. First, the sample cannot be
considered representative of all individuals in the United States.
Although the reported results are based on random samples of
individuals within each site and of randomly selected specific
site locations across the country, the type of sites where
observations were made was not randomly determined. That is,
eight specific types of sites were selected for observations
(e.g., retail and recreational) at the outset of the study, and
although diverse, these eight site types cannot be considered
24
representative of all physical environments across the country.
Although drawing a random sample of physical locations
across the country is methodologically desirable,
it was not practically feasible in the current project.
Another limitation with the littering rate reported in this
article is the potential bias toward large or more readily
observable items. The observed littering rate of 17% is
probably an underestimate for the true littering rate because
there were certainly littered objects that went undetected by the
field team. Small items, in particular, are likely to be
underrepresented using the observational protocol by virtue of
the difficulty in seeing them from a distance. It is also possible
that the mere presence of the research team in the environments
muted the littering rates, although the observational protocol
was designed to minimize this influence.
Just as the observational protocol is likely to underestimate
the littering rate, it is also likely to overestimate "intended"
littering. In coding behaviors in the field, proper disposals are
relatively easy to determine, as are intended littering behaviors.
Although the observational teamwas meticulousin observing
and coding behaviors, unintentional littering isinherently more
difficult to detect. As a result, the reported 81% of litter that is
intentional should be interpreted with caution. This limitation is
more applicable to the general littering observations and less
so for the focused smoker observations. Given that
intentional littering has been found to be more easily deterred
than unintentional littering (Sibley & Liu, 2003) and that we
recorded substantially more unintentional littering behavior, we
encourage tests of litter prevention techniques that promote
awareness and individual-level motivation.
Finally, we offer a caution on our interpretation of the ICC.
The ICC represents the degree to which the data "cluster", and
in our study, it quantifies the proportion of variance in the
dependent variable that is attributed to the site, rather than to
the individual. At one extreme, an ICC = 1.0 would indicate that
all of the variance in littering behavior was associated with site
such that all individuals observed within each site were the same
25
(either littering or not) but that littering occurred at some sites
but not others. On the other extreme, with an ICC = 0, all sites
would show the same littering rate, but individuals would vary
within each site. At the site level, we have used contextual
variables like the availability of trash receptacles or the amount
of existing litter as predictors. However, it isimportant to point
out thatsite-level variance could also be due to shared regional
or local norms associated with littering in different types of
locations or even shared norms about littering in general. To
illustrate, consider the case of cigarette butt disposal, for which
we found an ICC of .38. Although some of this clustering is
certainly due to contextual variables like the availability of an
ashtray,some may also be due to the strong norm against
smoking and littering in some contexts. For instance, had we
included cigarette butt disposal by staff smoking in a
designated area near an elementary school, the littering rates
would likely have been affected more by the norm of social
responsibility than by the availability of ashtrays.
Implications for Litter Prevention
The findings from this research point to several strategies for
litter prevention. These strategies include a combination of
both structural and motivational activities. This section of the
article provides a series of recommendations for litter
prevention that are consistent with the research findings.
Importantly, this is not an exhaustive list, and readers are
encouraged to think creatively about ways to link the reported


findings to litter prevention. In addition, it seems likely that
any single prevention activity will yield only small results, and
the most effective approach will utilize multi-pronged
strategies that target both structural and personal variables.
Beautification. The current results clearly show that litter
begets littering. This finding is not new, and indeed, it was
noted in the early studies of litter (e.g., Cialdini et al., 1990;
Keizer et al., 2008). However, although most of the early
studies presented participants with an object to either litter or
dispose of properly, the current research was completely
26
nonintrusive. We observed genuine behavior in a variety of
settings across the United States. Given this methodology, we
were able to learn that individuals use a variety of cues from
their surrounding environment to determine what is a common
and accepted behavior. The presence of litter communicates the
norm for that situation and the acceptability of littering. In
addition, the existing litter will require cleanup, so one more
piece may seem inconsequential.
To this end, a key to the success of any litter prevention
activity is to clean up and remove existing litter. Reducing the
amount of existing litter in a location is a surefire way to reduce
the rate of littering behavior (Casey &Lloyd, 1977; Huffman,
Grossnickle, Cope, & Huffman, 1995). In addition, prior
studies have found that involving community residents in
cleanup activities can promote a long-term reduction in litter
and increase an individual's motivation not to litter (RoalesNieto, 1988).
Behavioral opportunity. Related to the recommendation for
beautification efforts (above), there is also consistent evidence
for the importance of opportunity. That is, the context should
provide a convenient and accessible means for proper disposal
of trash and recyclables. Although the current results show the
widespread availability of receptacles in public places, results
also revealed that distance to a trash can was a strong predictor
of littering behavior. Providing easily identifiable, accessible
receptacles, with clear and recognizable messaging and
prompts, can go a long way toward reducing littering rates (De
Kort, McCalley, & Midden, 2008; National Cooperative
Highway Research program, 2009).
The issue of behavioral opportunity is especially important
for cigarette butts. The reported observational data suggest that
disposal of cigarette butts is more strongly clustered within
locations, yet less than half (47%) of the locations in the
sample provided an ash receptacle. Indeed, Liu and Sibley
(2004) reported a 64% drop in cigarette butt littering by adding
ashtrays on a university campus, although the change did not
affect attitudes about litter. Similar results were reported by
27
Geller, Brasted, and Mann (1980) and by Sibley and Liu
(2003). Given the increase in legislation prohibiting indoor
smoking, an increasing number of smokers are moving outside
to smoke. However, the infrastructure for collecting ashes and
lit cigarettes is woefully behind these policies, and the reported
data suggest that more efforts to afford smokers an opportunity
for proper disposal are needed.
Awareness and motivation campaigns. In addition to the
recommendations for beautification and infrastructure, there is
an important role for litter prevention strategies that target
individual-level motivation. The statistical analyses showed
that 85% of the variance in general littering and 62% of the
variance in cigarette butt littering resulted from individual
differences. These include demographic, attitudinal, and
motivational differences (among others), and they speak to the
importance of understanding the individual-level motivations
and barriers to littering (McKenzie-Mohr, 2002).
One way to promote individual-level motivations is through
outreach and media messages (Nolan, Schultz, & Knowles,
2009). Although prior research has shown that such campaigns
typically only produce small changes in behavior (if any), there
is reason to continue utilizing media messages, and more
importantly branding, in litter prevention efforts. Based on the
reported data, and background literature, messages should
highlight the dramatic decline in littering rates over the past 40
years, the generally infrequent over- all littering rate, and the
widespread disapproval for individuals who litter (see also


Cialdini, 2003).
In a related data set collected as part of the current study,
surveys were con- ducted with observed individuals randomly
sampled across the country. These surveys were conducted with
both litterers and nonlitters, and the findings show a near
unanimous disapproval for littering (Bator et al., 2011). This
finding, coupled with other research on the role of injunctive and
personal norms, suggests that messages should emphasize that
only a few deviant individuals litter and that these individuals are
disapproved of by the majority (see Cialdini, 2003; Grasmick,
28
Bursik, & Kinsey, 1991; Schultz, Tabanico, & Rendón, 2008).
In closing, the data reported in this article represent the largest
single study of littering behavior conducted to date. Data are
reported from unobtrusive observations of nearly 10,000
randomly selected individuals across 130 diverse public locations
across the country. The results show that of all the disposals that
took place in these locations, 17% resulted in litter. For disposals
of cigarette butts, the littering rate was even higher, at on
observed rate of 65%. Statistical analyses are reported that utilize
the multilevel framework and simultaneously examine both the
contextual and personal predictors of littering behavior. The
findingsshow that littering resultsfrom both personal and
contextual factors and that both are critical in understanding
littering behavior. This perspective is consistent with the
traditional approach utilized by environmental psychologists and
can be particularly instructive in efforts to reduce littering rates.
29
Author's Note
Supplemental Appendix of this article is available on the
Environment and Behavior's
Web site: Sage Publishing (<http://eab.sagepub.com/>.)
Acknowledgment
The authors want to acknowledge the excellent work and
commitment of their field research team: Jenna Albert, Sara
Aguilar, Michelle Cugini, Tracy Galea, Elizabeth Morales,
Belinda Rojas, and Michael Stringham. They also thank their
collaborating teams in New York and Vermont: Montgomery
Bopp, Kara Carpenter, Ashley Doyle, Cassie Fortney, Jamie
Kuhn, Nicole LeFevre, Andrea Martino, Eva Richardson, and
Ashlee Rock. Finally, they want to thank the collaborating
team in New Mexico: Angela Bryan, Maddia Ikeda, Jenna
Kicklighter, Stefan Klimaj, Eva Padilla, Jenna Tonelli, and
Kiani Wong. The authors want to express their appreciation for
the sup- port and encouragement of Susanne Woods and the
staff at Keep America Beautiful.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with
respect to the research, authorship, and/or publication of this
article.
Funding
The research reported in this article was conducted with
funding from Keep America Beautiful, using financial support
from Philip Morris, An Altria Company.
30
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35
Bios
P. Wesley Schultz is professor of psychology at California
State University, San Marcos. He earned his bachelor's degree
from the University of California, Irvine and his doctoral degree
from the Claremont Graduate University. His research interests
are in applied social psychology, particularly in the area of
sustainable behavior. His cur- rent work focuses on social
norms and the importance of social norms in promoting
conservation. He has worked on projects for a variety of
organizations, including the
U.S. Environmental Protection Agency, National Institute of
General Medical Science, National Institute of Justice, and the
California Integrated Waste Management Board.
Renée J. Bator is professor and cochairperson in the
psychology department at the State University of New York,
Plattsburgh. She completed her bachelor's degree in
psychology at the University of California at Santa Cruz. She
earned her MA and PhD from the Social Psychology Program
at Arizona State University. Her research inter- ests focus on
the application of persuasion theory to prosocial outcomes,
especially those with environmental or health benefits.
Lori Brown Large is project director at Action Research. She
earned her BA and MA degrees in sociology from California


State University, Fullerton. She has extensive experience in the
area of applied social science with an emphasis in survey
research design and implementation. Her particular interests are
in the area of waste reduction, energy conservation, and
pollution prevention. At Action Research she works with a
variety of organizations to develop, implement, and evaluate
outreach campaigns aimed at changing behavior.
36
Coral M. Bruni is a doctoral student at the Claremont
Graduate University. She completed her bachelor's and
master's degrees in psychology at California State University,
San Marcos. Her research interests include connectedness with
nature, self/identity, and implicit social cognition. Her recent
studies have focused on the role of implicit connectedness with
nature across a variety of ages and places.
Jennifer J. Tabanico is principal at Action Research. She
earned her BA degree in psychology and MA degree in
experimental psychology both from California State
University, San Marcos. Her research interests are in applied
social psychology with particular emphasis on the applications
of psychological theory to the development of public policy
and behavior change programs. In both academic and
professional appointments, she has completed numerous
studies of environmental attitudes, haz- ardous waste
management, energy conservation, and pollution prevention.
At Action Research, she works with a variety of organizations
to develop, implement, and evaluate outreach campaigns aimed
at changing behavior.


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Instruction processing in young and older adults: Contributions of memory span
Esther S. Kim PhD,Kathryn A. Bayles &Pélagie M. Beeson
Pages 753-762 \| Received 19 Jul 2007, Accepted 12 Nov 2007, Published online: 18 Jun 2008
Cite this article <https://doi.org/10.1080/02687030701803788>
Full Article Figures & data References Citations Metrics Reprints & Permissions Read this article
Abstract
Background: Age‐related changes in cognition and in particular, working memory, can impact older adults\' abilities to comprehend linguistic information. Many investigators have undertaken the study of age effects on language comprehension, but confounding variables, such as vocabulary level, general knowledge, and episodic memory ability limit what can be inferred about linguistic processing in ageing.
Aims: The purpose of this study was to investigate young and older adults\' performance on a language‐processing task that assessed ability to follow instructions. Despite having ecological validity, little attention has been paid to age effects on the processing of procedural information. The use of the instruction task allowed for an investigation of age effects on language comprehension while mitigating the effects of thematic knowledge, vocabulary and episodic memory.
Methods & Procedures: A total of 37 older adults (M = 72.1 years) and 41 young adults (M = 22.5 years) received three measures of verbal memory: digit span, word span, and listening span. In addition, they were administered an experimental instruction task requiring participants to sort coloured pills into pill containers in response to spoken instructions. Information load of the instructions was manipulated by varying the number of actions per instruction and the number of components to be remembered per action. For example, the instruction "Take three pills on Monday and two on Tuesday" has two actions, and each action has two components to remember (number of pills and day). The dependent variable was participants\' performance accuracy in following the instructions.


Outcomes & Results: Significant age effects were observed on the experimental instruction task, as well as on word and listening span measures. As the information load of the instructions increased, accuracy decreased for both groups, although this effect was greater for the older adults. When comparing instructions that had the same number of total components to be remembered, but differed in how these components were structured, participants performed more accurately when the instruction contained fewer actions, even if each action had more components to remember. Digit span was a significant predictor of performance on the instruction task, together with age accounting for more than half of the variance.
Conclusions: The results of this study demonstrate the expected age effects on working memory span capacity, and illustrate the effect of span capacity on following verbal instructions. From a practical perspective, these findings suggest that when a procedural instruction loaded with content is presented to an older adult, processing will be enhanced when it requires fewer actions.
Keywords: AgeingMemory spanWorking memoryInstructions.
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This project was supported in part by National Multipurpose Research and Training Center Grant DC‐01409 from the National Institute on Deafness and other Communication Disorders, and a Fellowship from the Cognitive Science Program at the University of Arizona.
Notes
1.  Values are reported using the Greenhouse‐Geisser correction for the variable "actions" as the homogeneity of variance assumption was violated.
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JOURNAL ARTICLE
Nutritional status and eating habits of people who use drugs and/or are undergoing treatment for recovery: a narrative review
Nadine Mahboub, Rana Rizk, Mirey Karavetian, Nanne de Vries
Nutrition Reviews, Volume 79, Issue 6, June 2021, Pages 627--635, <https://doi.org/10.1093/nutrit/nuaa095>
Published: 25 September 2020
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Abstract
A comprehensive overview is presented of the nutritional issues faced by people who use drugs or are undergoing treatment for recovery. Chronic substance use affects a person's nutritional status and body composition through decreased intake, nutrient absorption, and dysregulation of hormones that alter the mechanisms of satiety and food intake. Anthropometrics alone is not the best indicator of nutritional status, because this population has hidden deficiencies and disturbed metabolic parameters. Socioeconomic factors (eg, higher education, higher income, presence of a partner, living at home) positively affect nutritional status. Scarce available data on users undergoing treatment indicate improvement in anthropometric and metabolic parameters but with micronutrient intake remaining suboptimal. Weight gain is noted especially among women who use drugs and potentially increases their risk of relapse. Finally, specific amino acids and omega-3 fatty acids are promising in decreasing relapse and improving mental health during treatment; however, additional high-quality studies are needed. Nutrition intervention for people who use drugs or are undergoing treatment for recovery is underused; comprehensive programs addressing this population's unique needs are necessary. Future research will identify which components are needed.


drug users, health promotion, nutritional status, substance abuse treatment centers, substance-related disorders
Topic: dietbody compositionhabitsmicronutrientsweight gaineatingscience of nutritionnutritional statusdrug usagesubstance use disordersnarrative review
Issue Section: Lead Article
INTRODUCTION
Nearly 5% of the world population is currently estimated to use drugs once daily, and almost 0.6% suffer from severe drug use disorder.1 To date, opioids are the most harmful type of used drugs, and cannabis remains the world's most widely used drug.1
There are various types of treatments for drug addiction, including detoxification (complete abstinence) or opioid substitution treatment (OST).2 Drug detoxification mostly takes place initially in hospitals, followed by psychotherapy and behavioral modification in a therapeutic community or a rehabilitation center.3 By contrast, OST is a medication-assisted program during which the patient receives a long-term opioid agonist (methadone or buprenorphine) to reduce the withdrawal symptoms and decrease the cravings for street opioids.4 OST is suggested to be the more efficient method for reducing blood-borne illnesses like infection with the human immunodeficiency virus (HIV) and hepatitis.5
Drug use poses a cluster of harmful consequences to a person's well-being on psychological, emotional, and social levels.6 It leads to increased risk of infectious illnesses7 and medical issues, including mental disorders, cancer, stroke, and liver, lung, and cardiovascular diseases.8
Additionally, substance use can compromise the user's nutrition2 and greatly affects their dietary habits. In general, this population has a disrupted and chaotic lifestyle, and money is usually spent on drugs rather than on food. This severely affects the user's food intake, which eventually leads to undernutrition.9 Other factors affecting the nutritional status of drug users include the type, frequency, and duration of the drug used and the presence of infectious diseases.10 Furthermore, the type of treatment drug users might be receiving, such as being enrolled in a detoxification program and living in a rehabilitation center vs receiving OST and living in the community, might also influence their nutritional status.11


In this article, the literature on the nutritional issues faced by people who use drugs (PWUD) or those undergoing treatment for recovery is reviewed, as is the effect of drug use on dietary intake and dietary habits. The effect of drugs on anthropometric indices, body composition, nutrient deficiencies, and metabolic parameters are exposed, and the effect of nutrition on substance use and the changes that occur during treatment and recovery are discussed. The term malnutrition describes a state of imbalance---excess or deficiency---that leads to alteration in body composition and negatively affects the health status of the individual. In this article, the term malnutrition is used synonymously with undernutrition.
We chose to conduct a narrative review because there are many different topics in this field with few studies on each and statistical combination is impossible. These data will be compiled to have a comprehensive overview and provide new insights on drug users' eating patterns for future nutritional interventions in the promotion of good health among this population.
Various databases were searched for relevant literature (namely, PubMed, Google Scholar, Science Direct, and Medline), using the following terms: "nutrition" OR "nutritional status" OR "malnutrition" OR "dietary habits" AND "illicit drug use" OR "substance abuse" OR "drug use\*" OR "drug treatment." The keywords were modified according to the searched database. In addition, references of included articles were reviewed for inclusion when we thought they were relevant. Searches were restricted to English-language journals and a date range of 1990 until the present. A total of 83 studies initially were included in the review. Eight additional studies were suggested by key scholars; accordingly, the total number of studies included was 91.
Effect of drug use on dietary habits: food preferences, eating behaviors, and appetite regulation
Little research has been done to tackle the issues of food preferences and dietary habits of active drug users or those undergoing different treatment modalities. Cocaine drug users have irregular eating patterns and rely mainly on 1 meal taken late at night. Typically, this meal is high in refined carbohydrates and fat and low in fruits and vegetables.12--14 People addicted to opiates replace protein and fats with meals high in sugar and alcohol, which are low in essential nutrients and, therefore, are sources of empty calories.9 Substantial evidence supports the increased preferences for sweet taste among PWUD.15--20


During the early phase of detoxification, when patients are still receiving pharmacotherapy, they report a period of low food intake, and eating becomes their last priority as they experience nausea, anorexia, and gastrointestinal disturbances, all of which make eating difficult.12,19 Between the first and sixth month of detoxification, a high preference and craving for table sugar and sweet foods, such as cakes and confectionary foods, often takes place as a replacement for the drug. However, in the later recovery phase, after 6 months, sugar cravings seem to level off with more structural food intake and improved appetite.17,19,21
Studies of persons receiving OST also show higher preference and intake of sugary foods15,22--24 (eg, high consumption of tablesugar, yogurt, and soft drinks), with very little intake of fruits and vegetables.25,26 Sugary foods appear to be the preferred foods for PWUD or those undergoing treatment. This preference may be an indication of addictive tendencies, because some studies show that heroin users have these cravings prior to using heroin more than after using it.27
The poor dietary habits decreasing food intake, the preference for sugary foods contributing to empty calories, the compromised liver storage and/or increased excretion of nutrients with accompanying diseases like HIV and hepatitis are major risk factors for malnutrition and hazardous health among PWUD.28
Nutrition knowledge seems to affect dietary choices in this population. For instance, when nutrition knowledge was offered as part of an OST program, sugary food craving was still observed but healthier foods and more meals were consumed by the participants.18


Effect of drug use on dietary intake: macro- and micronutrients
In the short term, opiates cause anorexia, decreased food consumption, and reduced gastrointestinal motility, all leading to malnutrition and increased risk of infections in the long term.29 Socioeconomic factors like education and income are positively associated with nutritional indices like body mass index (BMI), hemoglobin level, and serum protein levels among PWUD. This association is in agreement with the well-documented fact that socioeconomic factors are related to the nutritional status of the individual, in addition to the high prevalence of self-reported homelessness among PWUD.20,30 Similarly, people who use heroin and cocaine have lower energy and protein intake than nonusers.16,31 This intake seems to decline more with higher intensity and duration of drug use.10 The presence of disease also appears to affect food intake. HIV-positive PWUD have more energy, protein, and fat-deficient diets compared with PWUD who are HIV negative.28 The high levels of food insecurity among this population are mainly due to the limited funds, which are usually allocated to the support of their habits rather than food; this leads to serious decrease in intake levels.
Consistent with the lower intakes of nutrient-dense foods in this population, the intake of the majority of vitamins and minerals, like thiamin, riboflavin, pyridoxine, folate, vitamin D, vitamin C, magnesium, iron, calcium, zinc, copper, and selenium is below the recommended intake.32 The nutritional imbalance (a higher ratio of macronutrients to micronutrients) indicating higher intakes of empty calories is strongly associated with drug use.33
Effect of drug use on plasma nutrient deficiencies
The malnutrition of PWUD, assessed by anthropometric measurements, is not usually very severe; thus, measuring the plasma levels of macronutrients and micronutrients might reveal hidden deficiencies that reflect the decrease in the intake of these nutrients.


Essential nutrients are depleted among PWUD in general.15 This population exhibits low selenium and potassium levels due to lower muscle mass attributed to malnutrition.34 Iron deficiency and iron-deficiency anemia are widespread, mostly among female PWUD,35--37 as are low plasma levels of vitamins A, C, D, and E. The latter is inversely correlated with the dose and period of addiction.16,30,35 These deficiencies are mainly caused by restricted access to foods, in addition to the food choices previously discussed.16,30,35 Thus, the issue of vitamin and mineral supplementation among PWUD and during treatment requires additional consideration.
On the other hand, the plasma levels of some minerals are reported to be higher in this group compared with healthy individuals. This is not due to proper nutrition but rather is attributed to factors unique to PWUD. Higher serum levels of phosphorus, sodium, and magnesium are tentatively attributed to partial dehydration.15 Similarly, increased serum levels of copper and zinc are due to inflammation, acute fasting, and smoking.15,34,36
Effect of drug use on anthropometric indices and body composition
Although scarce, the majority of the literature assessing the nutritional status of PWUD mostly points toward malnutrition.11 The relation among drug use, body weight, and BMI has been addressed in many epidemiological studies, and most of the evidence shows an inverse correlation among these variables.28,38 On admission for detoxification, up to 70% of PWUD have BMI values below the normal range or weight values below the population mean.10 Similarly, Ross et al35 showed that 24% of PWUD, within a short period of admission for detoxification, exhibited mild to moderate malnutrition, based on the Subjective Global Assessment.


In general, the BMI of PWUD is lower than that of nonusers. HIV-positive persons who use cocaine have the lowest BMI, as compared with users of other drugs or with nonusers.39 It is believed that cocaine suppresses appetite and decreases food intake, and subsequently body weight, by inhibiting dopamine transporters, decreasing reuptake of serotonin, upregulating the glucocorticoid production, and increasing the cocaine- and amphetamine-regulated transcript expression.40,41 Cowan et al21 supported this finding when reporting that weight was gained with the cessation of cocaine use. Ersche et al13 challenged the assumption that cocaine leads to weight loss through appetite suppression; rather, they suggested that metabolic alteration is the cause. Their findings showed that cocaine users had lower body weight and fat mass as compared with nonusers, despite reporting higher dietary fat and carbohydrate intake.
People who smoke heroin appear to have a lower BMI and body weight than nonusers. This inverse correlation is modulated by the high frequency (\>3 times/d) and the route of administration of the drug.38 The significant negative contribution of smoked heroin to body weight and BMI may be due to faster rate of brain delivery of the drug as compared with injection, snorting, or oral ingestion, leading to greater reinforcing effects. Substances like heroin may compete with food in the brain activating reward pathways and increasing dopamine receptor' availability, thus suppressing the appetite and leading to lower body weight. This is particularly noted among heroin smokers.38,42--45
McIlwraith et al46 showed that heroin users are more prone to being underweight as compared with morphine and amphetamine users, whereas people who use amphetamines were at higher risk of being obese as compared with morphine users. This finding is contradictory to the appetite-suppressing effect of amphetamine, and its relevance to the general population will need to be investigated by future studies, because this increase in obesity was found only in comparison with morphine users and not with a nondrug-using control group.46,47


Methylamphetamine (MA), a relatively new psychostimulant (the second most widely used drug now after heroin, marijuana, and others) is associated with cardiac and hepatic pathology, neurological impairment, mood disorders, and malnutrition.48 People dependent on MA have a lower BMI as compared with that of healthy individuals. This might be due to cognitive deficits, abnormal metabolic activity, duration of MA use, and improper oral health that affects food chewing and, thus, intake.48,49 More frequent use of other types of drugs such as marijuana or sedatives showed a weak association with a lower BMI, although this association is statistically not significant.39,50
In addition, sex might influence the BMI, weight, and body composition of PWUD. Women who are heavy drug users (ie, using methadone or injection of drugs \>16 times/wk) have less body fat and lower BMI as compared with PWUD moderately or infrequently, and nonusers. This difference among different levels of drug use is not present in men.51 This study by \"Cofrancesco et al.51\" confirms the results of studies that showed a negative relation between drug use and BMI solely among women and not men.10,52,53
Furthermore, factors like decreased frequency of food consumption are negatively associated with body weight and BMI. Also, poverty resulting from unemployment, common among PWUD, leads to an inability to purchase nutritious foods and is associated with a low BMI. In addition, multiple drug use can lead to poorer nutritional status due to the appetite-suppressing effect of the drug.20,28,30
Interestingly, Richardson et al54 showed that BMI alone may not be the best indicator to assess PWUD because there was no association between BMI and the nutritional risk level of PWUD when screened. Using other tools to assess appetite, diet quality, and biochemical parameters better identified nutritional deficiencies to be addressed.35


Throughout treatment processes, whether by OST or detoxification, PWUD start to consume healthier foods and more structured meals.19,21,26 Better dietary habits are seen among those in residential homes where meals are provided, or later in recovery when food preparation becomes a more sociable and satisfying activity as compared with PWUD who have severe addiction and for whom eating is given little consideration.19Table 1 summarizes the factors contributing to changes in anthropometric indices and body composition among PWUD.
Table 1Factors contributing to lower body weight, BMI, and body composition among drug users
Factor Finding
Sex Underweight is more frequent among women than men.
Type of drug
Heroin: highest percentage of drug users in underweight category
Cocaine: decrease in weight specific to fat mass with no significant changes in BMI
Amphetamines: higher risk of obesity in users as compared with morphine users
Methylamphetamines: lower BMI as compared with nonusers
Frequency and route of administration
Multiple drug use for a long duration is negatively associated with the nutritional status.
Smoking has faster delivery of the drug to the brain, resulting in a lower BMI as compared with snorting or injection.
Food insecurity and poverty Negative effect on the nutritional status by decreasing body weight, body fat, and BMI
Pathological diseases Add to the severity of malnutrition among drug users
Treatment Healthier dietary habits seen in detoxification and OST
Abbreviations: BMI, body mass index; OST, opioid substitution treatment.


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Effect of drug use on plasma metabolic parameters
The effect of drug use on plasma parameters has also been studied with emphasis on lipid profile, glucose and hemoglobin levels, and hematocrit. In general, plasma total cholesterol has an inverse relation with drug use. Persons addicted to opium, heroin, and MA have a significant decrease in serum cholesterol level as compared with nonusers but with no change in triglyceride levels.49,55--58 By contrast, comparing HIV-positive and HIV-negative injecting drug users with a control group, total cholesterol levels were lower and triglyceride levels were significantly higher in the HIV-positive drug users, indicating the possible effect of the disease itself and not the drug use.28 These findings were supported by Maccari et al,59 who found that heroin users had significantly lower serum cholesterol and high-density lipoprotein levels, and higher triglyceride levels than nonusers. The aforementioned decrease in serum lipid levels could be mainly attributed to malnutrition and weight loss, specifically the loss of abdominal fat, in addition to the presence of liver diseases or HIV that are common among heroin users.
Decreased plasma cholesterol levels have been associated with many negative psychological behaviors, including aggression, depression, and suicide60; however, this remains controversial. Low plasma cholesterol levels can alter tissue concentration of polyunsaturated fatty acids, the depletion of which has important consequences on modulating the serotonergic and dopaminergic functions that play key roles in the aforementioned behaviors. Yet, to date, a causal relationship has not been shown.58,61--63 Persons addicted to cocaine who relapsed after detoxification had lower plasma cholesterol values (\<160 mg/dL) than those who did not, suggesting an increased vulnerability to the development of behavioral and psychological disorders with low cholesterol levels.55 Whether these diminished levels are associated with drug craving still needs to be investigated.


Glucose is another parameter that was studied in PWUD and remains not well understood. In a study by Zhang et al,48 the fasting blood glucose levels of persons addicted to MA were lower than those of control participants. This finding runs in parallel with studies done on animals that reported a direct effect of MA on the pancreas, leading to insulin secretion and induced hypoglycemia.64 On the other hand, non-insulin dependent persons with diabetes who used opium had higher glycosylated hemoglobin values than did nonusers, thereby indicating elevated blood glucose levels in the former for the previous 3 months.65 The effect of morphine on glucose has been demonstrated in animals, with several mechanisms suggested, like an increase in hormone levels including adrenalin, noradrenalin, corticosterone, and glucagon; these, in turn, increase blood glucose levels.66,67 Among the very few studies on humans, Carey et al68 showed that morphine can induce a reduction in the plasma counterregulatory epinephrine response, thus causing hypoglycemia symptoms in healthy individuals without diabetes. More studies are needed to confirm if behavioral factors play a role in the effect of drugs on plasma glucose levels.
Hemoglobin and hematocrit levels are lower in PWUD than in nonusers, with the lowest levels seen among multiple-drug users and those with longer duration of addiction.30 This finding was related to malnutrition and decreased micronutrient intakes, especially iron.69 The decrease in hemoglobin levels and hematocrit among PWUD is specifically noted among women. This might be because men are institutionalized for a longer period than women and that, in turn, correlates with better nutritional status.32,35


Nutritional changes during recovery (detoxification or OST)
In addition to being an effective method for reducing harm, OST or methadone maintenance treatment (MMT) also improves the nutritional status of PWUD, whereby the BMI and weight of users starting treatment significantly increase.70,71 The increased weight and BMI are mostly seen in patients with higher education and income, suggesting a positive role of social factors on the nutritional status of PWUD.20,30,70,72 From the patients' point of view, MMT has a positive impact on their physical health, sleep, and weight gain.73 They report better appetite, change in taste, and more desire to eat.
PWUD starting MMT show a decreased intake in the majority of the nutrients (ie, fats, cholesterol, fibers, and some minerals and vitamins) 2 months after beginning treatment, followed by an increase after 9 months.74 Sex might modulate the effect of MMT on weight gain. W hereas studies show an increase in dietary intake, body weight, BMI, and skin fat folds among men, as compared with a modest weight loss in women,74 other studies show the opposite, with women having a much greater increase in BMI and weight than men.75 The reason underlying this significant difference between sexes does not seem to be related to the duration of the treatment and needs additional investigation. The increase in weight and BMI may not be due to the shift toward a healthier eating pattern but might be related to the pharmacological aspect of the treatment itself.23,75,76 Detoxification also results in increased weight and food intake,77--79 which vary at different recovery stages. In the early stages, binge eating is observed as a result of the replacement of drugs with food. Binging may be related to changes in the eating behaviors of PWUD after periods of food restriction caused by drugs. In later stages of their recovery, PWUD developed more structured and less frequent overeating habits.21


The studies regarding the effect of MMT on some metabolic parameters are limited. After 6 months of MMT, persons addicted to opioids show an increase in serum levels of leptin, total cholesterol, high-density lipoprotein , and low-density lipoprotein, compared with serum levels before initiation of the treatment.70,80 A positive correlation has been shown between leptin, BMI, and serum lipid levels, with greater effect among women; this is attributed to the difference in percent body fat mass.
As for micro- and macronutrient intake during MMT or detoxification, an increase in the overall intake of energy, proteins, and carbohydrates occurs with both modalities after initiation of the treatment. Yet, this is followed by a decrease in later stages of recovery, when the food intake starts to become more structured. Interestingly, intake of the majority of the minerals remains below the recommended levels, especially in patients with HIV; this could be related to the increased intake of energy-dense foods rather than nutrient-dense ones.24,81
Personal and environmental factors like decreased physical activity and the purchase of high-fat, less-expensive foods play a role in the weight gain seen among patients in recovery from drug use, thereby highlighting the need to incorporate exercise and nutrition information as part of the treatment.82 Exercise reduces stress, anxiety, depression, and drug use in individuals recovering from substance use.83
Better nutrition knowledge and healthier eating habits are seen among PWUD in MMT after receiving nutrition lectures as part of the treatment program, although no effect on BMI and weight gain is seen. This could be because the intervention program emphasized the healthier eating habits and did not specifically target weight reduction.84


Concerns about weight gain among women drug users in recovery is a potential risk factor for relapse. In a study of 297 women of different ethnicities who were recruited from 7 different treatment facilities, Warren et al79 reported that 70% were concerned about weight gain during recovery, and 45% were concerned about relapse because of this gain. One-third of the sample indicated that weight loss was a reason to initiate drug use to start with. Similarly, drug use was positively associated with overweight among female adolescents.85 Data revealing drug users' perceptions about the kind of intervention programs for tackling the weight gain they face during treatment are scarce. Most of the research suggests similarities between women and men in terms of drug-use behaviors; however, significant differences exist that may indicate a need for more sex-specific research on prevention and treatment strategies.85 On the basis of these findings, giving individualized behavioral recommendations must be considered, because all intervention research shows its efficiency. Table 2 summarizes the effect of drug use and treatment on different aspects of the nutritional status of PWUD.
Table 2Effect of drug use and treatment methods on the nutritional status
Drug use OST Detoxification
Food preferences Consumption of 1 meal/d with higher preference for sugars and fats and lower intakes of fruits and vegetables
Better appetite and increased number of meals
High consumption of sugars, yogurt, and soft drinks with low intakes of fruits and vegetables
Binging on sweets in early phases of treatment with more structured food intakes in later recovery stages
Macro- and micronutrient intake
Deficits in energy and protein
Majority of vitamins and minerals below RI
Higher energy, proteins, and carbohydrates after initiation of treatments, with a decrease in later stages Higher energy, proteins, and carbohydrates after initiation of treatments, with a decrease in later stages.
Plasma nutrients
Low levels of Se, K, Fe, vitamins A, D, C, and E
High levels of Mg, Na, and Ph attributed to dehydration


Majority of micronutrient levels stayed below the recommended levels. Majority of micronutrient levels stayed below the recommended levels.
Anthropometrics Decrease in BMI and weight with variations based on the type of drug Significant increase in BMI and weight, with more significance in women, placing them in the overweight category. Increase in weight and food intake in early stages of recovery
Metabolic parameters Low levels of total and HDL-cholesterol, leptin, FBS, Hct, and Hb Increase in total and HDL-cholesterol and leptin levels
Abbreviations: BMI, body mass index; FBS, fasting blood sugar; Fe, iron; Hb, hemoglobin; Hct, hematocrit; HDL, high-density lipoprotein; K, potassium; Mg, magnesium; Na, sodium; OST, opioid substitution treatment; Ph, phosphorus; RI, recommended intake; Se, selenium.


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Effect of nutrition on substance use
The high prevalence of PWUD with mood disorders like depression and anxiety has been confirmed by numerous, large epidemiological studies86--88 and these disorders, in turn, may have a negative impact on users' recovery, which will lead to relapse.15,89 Essential micronutrients play an important role in mood regulation by the brain,33 and deficiencies or insufficient intakes of these nutrients, in addition to food deprivation, correlate with poor mental health, especially depression.90,91 Serotonin plays a role in the modulation of many behaviors, including violence, aggression, mood, sleep, and appetite.92,93 The synthesis of serotonin starts with the amino acid tryptophan. Increasing dietary intake of tryptophan can increase serotonin levels, thus modulating the aforementioned behaviors. Data in the literature concerning the positive effect of tryptophan supplementation on depression are inconsistent; consensus has not yet been reached regarding the effectiveness in the treatment of drug use.93--95 Tyrosine and phenylalanine are also involved in the synthesis of dopamine and catecholamines that influence behavioral performance, with limited and inconsistent evidence that their supplementation is beneficial in the treatment of PWUD.15,95,96 When patients dependent on heroin or opiates are given a combination of amino acids (namely, phenylalanine, tryptophan, tyrosine, and glutamine) while undergoing detoxification, they show a significant reduction in the craving for opiates.97 This might be an important tool in the treatment of drug use that warrants additional study.
The provision of micronutrients is required as a cofactor for the synthesis of serotonin, dopamine, and catecholamines.98,99 Deficiencies of copper, selenium, manganese, magnesium, folate, and B-complex vitamins are linked to depression,98,100--102 which might hinder the treatment process of drug users. Vitamin and mineral supplementation should be considered, not only for the management of malnutrition but also as a preventive measure of relapse.


Furthermore, fatty acids are also involved in regulating the aforementioned behaviors.103,104 Elevated levels of corticotropin-releasing hormone, which is associated with defensive and violent behaviors, decrease with supplementation of a combination of omega-3 fatty acid docosahexaenoic and eicosapentaenoic acids.105 Patients undergoing detoxification from drug use have a decrease in anger score upon supplementation with docosahexaenoic acid, whereas lower anxiety scores are associated with supplementation with eicosapentaenoic acid.106
Supplementation could have a positive effect on the psychological behaviors that might prevent relapse. The intake of specific nutrients like amino acids and omega-3 fatty acids are promising in decreasing relapse and improving mental health during treatment, but additional high-quality studies are needed to provide evidence that such supplementation can increase the efficacy of the treatment of PWUD.
CONCLUSION
PWUD are a vulnerable population, and most of the research exploring their nutritional status points to malnutrition. Substance use affects the nutritional status and body composition through decreased food intake and nutrient absorption, altered metabolism, and use of multiple drugs, in addition to the dysregulation of hormones altering the mechanism of satiety and food intake. Anthropometric measurements alone are not the best indicators of assessment in this patient population, because active users and those seeking treatment have many hidden deficiencies and disturbed metabolic parameters. Socioeconomic factors like education, income, presence of a partner, and living in a residential home where meals are provided have a positive impact and should be considered.
Scarce available data indicate improvements in the anthropometric and metabolic parameters of PWUD when they initiate treatment, but micronutrient levels remain below recommended intake values. Yet, an increase in weight is noted, which might pose negative health implications.
All of these factors draw attention to the importance of proper, comprehensive nutrition care being provided for drug users and in treatment centers. Simple nutrition education about healthy eating habits improves the quality of the nutritional intake of PWUD but does not seem to be solely effective in treating the problems faced by users and those undergoing treatment and improving their outcomes. This indicates the need for an individualized and comprehensive nutritional intervention. The components of this intervention still need to be determined by future studies.


\$ gz sim \--help
Environment variables:
GZ_SIM_RESOURCE_PATH Colon separated paths used to locate resources such as worlds and models.
GZ_SIM_SYSTEM_PLUGIN_PATH Colon separated paths used to locate system plugins.
GZ_SIM_SERVER_CONFIG_PATH Path to server configuration file.
GZ_GUI_PLUGIN_PATH Colon separated paths used to locate GUI plugins.
GZ_GUI_RESOURCE_PATH Colon separated paths used to locate GUI resources such as configuration files.
37
Tutorial:
Dynamic level-of-detail loading
38
\$ gz sim levels.sdf \--levels
39
For Ubuntu binary installs, more example worlds are in /usr/share/gz/gz-sim7/worlds/
levels.sdf
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Level of detail (LOD) concept:
For large worlds, set up SDF to dynamically load models based on distance from robot
Used in DARPA SubT
Follow tutorial (see next slide) gazebosim.org/api/sim/7/levels.html
TODO(nice to have) replace with video after running commands on next page
\$ gz topic -t \"/model/vehicle_blue/cmd_vel\" -m gz.msgs.Twist -p \"linear: {x: 4.0}\"
\$ gz topic -t \"/model/vehicle_red/cmd_vel\" -m gz.msgs.Twist -p \"linear: {x: 2.0}\"
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levels.sdf
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Dynamic load/unload in vicinity of moving blue vehicle
levels.sdf
43
levels.sdf
44
Tutorial:
Using sensors
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Using sensors
Tutorial detailed walkthrough: gazebosim.org/docs/garden/sensors
Quick try: Download code files into a directory called sensors github.com/gazebosim/docs/tree/master/garden/tutorials/sensors
Files you need: CMakeLists.txt lidar_node.cc sensor_launch.gzlaunch sensor_tutorial.sdf
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Compile:
\$ cd sensors
\$ mkdir build && cd build
\$ cmake ..
\$ make
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Run:


modules with performance ratios derived from extensive experimental field data is
arguably the most valid approach to assessing the level of energy performance that
can be expected of a PV system today. Conversely, defaulting to measured
11
electricity generation records from existing installations only returns an aggregated
measure of the performance of a long chain of system components, some of which
are likely to be no longer representative of the current state of technological
advancement, and is therefore not a viable alternative if one wishes to faithfully
portray a technology that is still in such a state of flux.
We herein present the results of our new EROI calculations for a range of modern
PV systems (mono-crystalline Si, multi-crystalline Si, ribbon Si and CdTe thin film),
based on the most recent published LCA studies by ourselves and other colleagues
(Fthenakis et al., 2009; Held and Ilg, 2011; Fthenakis and Kim, 2011).
Data were normalized to assume conservative performance ratios (PR) of 75% for
rooftop mounted systems and 80% for ground mounted optimal latitude installations,
which also implicitly account for module degradation (Fthenakis et al., 2011). In all
cases, the complete PV system was addressed, including all balance of system
(BOS) components, and the analysis was extended to the full life cycle, including
take back and recycling, and assuming an industry-standard PV system lifetime (T)
of 30 years (Fthenakis et al., 2011). We also adopted the average southern
European ground-level insolation, i.e. 1,700 kWh/(m2
·yr), which incidentally
coincides with the mean global insolation (horizontal surface) in between the Arctic
and Antarctic circles (NASA, 2008). Finally, the EU-27 electric grid efficiency (ηgrid =
0.31) was used, when called for, to convert the electricity generated by PV into its
'Primary Energy equivalent', in accordance with the common practice for EPBT
calculations.
Our full EROI calculations for PV are illustrated in Table 1.
For comparative purposes, we also calculated the EROI of oil- and coal-fired
thermal electricity. We took the primary energies required for the respective power
plants (EPP) and the total direct inputs of feedstock energies over their 30-year
lifetimes (EFeed) from the reputable LCA database Ecoinvent v.2 (Jungbluth, 2007;
12
Dones et al., 2007; Ecoinvent, 2011); we then back-calculated EED for each as
EFeed/EROIF.
Our full EROI calculations for oil- and coal-fired thermal electricity are illustrated in
Tables 2 and 3.
13
Table 1 EROI calculations for PV. LCI data from (Fthenakis et al., 2009; Held and Ilg, 2011; Fthenakis and Kim, 2011)
Ref. Eqn. Mono-c Si (rooftop) Multi-c Si (rooftop) Ribbon Si (rooftop) CdTe (ground)
Insolation \[kWh/(m2
·yr)\] 1,700 1,700 1,700 1,700
Performance Ratio 0.75 0.75 0.75 0.8
Module efficiency 14% (a) 13% 13% 11% (a)
EOUT,yr \[kWhel/(m2
·yr)\] 179 166 166 150
T \[yr\] 30 30 30 30
EOUT \[kWhel/(m2
)\] 5,355 4,973 4,973 4,488
EPP \[MJPE/m2


\] 3,257 3,057 1,907 1,375
Eqn. 2 EROIel = EOUT/EPP 5.9 5.9 9.4 11.8
ηgrid 0.31 0.31 0.31 0.31
EOUT-eq,yr = EOUT,yr / ηgrid
\[MJPE-eq/(m2
·yr)\] 2,073 1,925 1,925 1,737
EPBT = EPP/EOUT-eq,yr \[yr\] 1.6 1.6 1.0 0.8
Eqn. 4 EROIPE-eq = T/EPBT 19 19 30 38
(a) It is noted that current efficiencies of mono-c Si and CdTe PV are slightly higher than those stated here; correspondingly, their EROIs are
also higher.
Subscripts to energy units stand for: el = electricity; PE = Primary Energy; PE-eq = 'Primary energy equivalent' (based on ηgrid).
14
Table 2 EROI calculations for oil-fired thermal electricity. LCI data from
(Ecoinvent, 2011; Jungbluth, 2007)
Ref. Eqn. minimum maximum
EROIF 10 30
EPP \[MJPE/(plant unit)\] 1.90·109 1.90E·109
PP units per kWhel output
\[(plant units)/kWhel\]
1.18·10-11 1.18·10-11
EPP \[MJPE/kWhel\] 2.24·10-2 2.24·10-2
EOUT \[kWhel\] 1 1
EFeed \[MJPE/kWhel\] (a) 9.5 9.5
EED = EFeed/EROIF
\[MJPE/kWhel\]
0.95 0.32
Eqn. 2 EROIel = EOUT/(EPP+EED) 3.7 10.6
(a) Weighted average for European (UCTE) oil-fired electricity.
Subscripts to energy units stand for: el = electricity; PE = Primary Energy.
Table 3 EROI calculations for coal-fired thermal electricity (without Carbon
Capture and Storage). LCI data from (Ecoinvent, 2011; Dones et al., 2007)
Ref. Eqn. minimum maximum
EROIF 40 80
EPP \[MJp/(plant unit)\] 2.68E·109 1.60E·109
PP units per kWhel output
\[(plant units)/kWhel\]
1.04·10-11 1.31·10-11
EPP \[MJPE/kWhel\] 2.79·10-2 2.09·10-2
EOUT \[kWhel\] 1 1
EFeed \[MJPE/kWhel\] (a) 10.7 10.1
15
EED = EFeed/EROIF
\[MJPE/kWhel\]
0.27 0.13
Eqn. 2 EROIel = EOUT/(EPP+EED) 12.2 24.6
(a) Weighted averages respectively for European (UCTE) lignite-fired electricity
('minimum' column) and hard coal-fired electricity ('maximum' column).
Subscripts stand for: el = electricity; PE = Primary Energy.
4. Discussion
Starting with the most straightforward approach, i.e. adopting the system boundaries


illustrated in Figure 1 and applying Eqn. 2, we may compare the ensuing EROIel of
PV electricity to the EROIel ranges for oil-and coal-fired thermal electricity (Figure 2).
0
2
4
6
8
10
12
14
16
18
20
22
24
26
mono-c Si
PV
electricity
multi-c Si
PV
electricity
ribbon Si
PV
electricity
CdTe PV
electricity
Oil-fired
electricity
(min.)
Oil-fired
electricity
(max.)
Coal-fired
electricity
(min.)
Coal-fired
electricity
(max.)
EROI
Figure 2 EROIel of PV electricity, compared to the EROIel of oil- and coal-fired
thermal electricity (Eqn. 2)
16
These results show that, when accounting for the 'energy return' as a straight
Energy Carrier (i.e. electricity as such), the resulting EROIel of PV spans
approximately the same range (EROIel ≈ 6 -- 12) as the EROIel of conventional oilfired electricity systems (EROIel ≈ 4 -- 11), while the EROIel of coal-fired electricity
systems come out approximately double of that of PV (EROIel ≈ 12 -- 24). However,
it should not be forgotten that thermal electricity production, and coal-fired systems
in particular, suffer from much higher life-cycle greenhouse gas emissions than PV
(Fthenakis and Kim, 2011), which would be energy-intensive to reduce by means of


## and N2 O by the respective global warming potential (GWP) to calculate CO2
Natural Gasoline 66.88 3.0 0.60
Other Oil (\>401 deg F) 76.22 3.0 0.60
Appendix A: Default Emission Factors
U.S. EPA Center for Corporate Climate Leadership -- GHG Inventory Guidance 21
Direct Emissions from Stationary Combustion Sources
Fuel Emission
Factors
Petroleum Products (continued) (kg CO2
/mmBtu) (g CH4
/mmBtu) (g N2
O/mmBtu)
Pentanes Plus 70.02 3.0 0.60
Petrochemical Feedstocks 71.02 3.0 0.60
Petroleum Coke 102.41 3.0 0.60
Propane 62.87 3.0 0.60
Propylene 67.77 3.0 0.60
Residual Fuel Oil No. 5 72.93 3.0 0.60
Residual Fuel Oil No. 6 75.10 3.0 0.60
Special Naphtha 72.34 3.0 0.60
Unfinished Oils 74.54 3.0 0.60
Used Oil 74.00 3.0 0.60
Table A-4: Emission Factors for Equation 2 (EF2
) - Emissions per Energy Unit for Biomass Fuel Combustion
Fuel Emission
Factors
Biomass Fuels (Solid) (kg CO2
/mmBtu) (g CH4
/mmBtu) (g N2
O/mmBtu)
Agricultural Byproducts 118.17 32 4.2
Peat 111.84 32 4.2
Solid Byproducts 105.51 32 4.2
Wood and Wood Residuals 93.80 7.2 3.6
Biomass Fuels (Gaseous)
Landfill Gas 52.07 3.2 0.63
Other Biomass Gases 52.07 3.2 0.63
Biomass Fuels (Liquid)
Biodiesel (100%) 73.84 1.1 0.11
Ethanol (100%) 68.44 1.1 0.11
Rendered Animal Fat 71.06 1.1 0.11


## and N2 O by the respective global warming potential (GWP) to calculate CO2
Vegetable Oil 81.55 1.1 0.11
Biomass Fuels (Kraft Pulping Liquor, by Wood Furnish)
North American Softwood 94.4 1.9 0.42
North American Hardwood 93.7 1.9 0.42
Bagasse 95.5 1.9 0.42
Bamboo 93.7 1.9 0.42
Straw 95.1 1.9 0.42
Source for the emission factors in this appendix: Solid, gaseous, liquid, and biomass fuels: Federal Register (2009) EPA; 40 Source for the
emission factors in this appendix: Federal Register (2013) EPA; 40 CFR Part 98; 2013 Revisions to the Greenhouse Gas Reporting Rule and Final
Confidentiality Determinations for New or Substantially Revised Data Elements; Final Rule. November 29, 2013. Table C-1, Table C-2, Table AA-1.
<http://www.gpo.gov/fdsys/pkg/FR-2013-11-29/pdf/2013-27996.pdf>.
Appendix A: Default Emission Factors


are the followings:
• The contents and the visual presentation of the EPCs.
The usability and therefore the credibility of the certificate
is highly influenced by the level of information shown on
it as well as by the way this information is accessible to a
wide range of users, from professionals to building owners.
• The assessment method. The EPC quality depends
strongly on the assessment methodology of the EPC
scheme. For instance the preference for a rating system and the corresponding energy classes as well as the
amount and the accuracy of the default values influence
significantly the quality of the EPC.
• The public awareness on EPCs. The level of public awareness and the quality of the promotional campaigns are important factors in increasing the usability of the EPCs. The
market campaigns for promoting the EPCs are especially
influential for the building owners and users, but should
properly address all the users' categories in order to be
effective.
• The level of enforcement. The non-compliance and the
poor quality of the certifiers' assessment may create serious doubts on the real value of the EPC. Therefore, the
level of enforcement and the related penalties for noncompliance and bad execution are determinant for the usability of the EPC scheme.
Table 2: Main characteristics of the EPCs in selected countries.
AT BE CZ DK FR
Res Non-res
DE HU IE NL PL PT ES
Label classes A++ A+ No A A A A No A+ A1A2A3 A++ A+ A No A+ A A
A sliding
scale B B B B sliding
scale A B1B2B3 B sliding
scale B, B- B
B C C C C B C1C2C3 C C C
C D D D D C D1D2 D D D
D E E E E D E1E2 E E E
E F F F F E F F F F
F G G G G F G G G G
G H G
I
Performance
indicator kWh/m2a kWh/m2a GJ/year
No
specific
info
No specific info kWh/m2a No specific
info
kWh/m2a
and CO2-
emission
Energy
index
No
specific
info
kWh/m2a
No
specific
info
Label
present situation
of the building
Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Label after
implementing the


Table 1. Energy data on spring-based energy storage systems.
Reference Power density Gravimetric energy density Volumetric energy density
Steel coiled spring \[26\] - 0.14 kJ/kg 1080 kJ/m3
CNT yarn spring \[21\] - 4.20 kJ/kg 4900 kJ/m3
CNT yarn spring-driven
electromagnetic generator \[14\]
2500 W/kg 0.88kJ/kg 1770kJ/m3
Twisted CNT \[22\] - 8.30 kJ/kg -
Batteries \[5\] 100-2000 W/kg 20-576 kJ/kg 54000-1.6·106 kJ/m3
Compressed Air Energy Storage \[5\] - 12.60 kJ/kg 18000 kJ/m3
Flywheel Energy Storage \[5\] 12000 W/kg 18-360 kJ/kg -
Supercapacitors \[5\] 800-20000 W/kg 7-100 kJ/kg 36000 kJ/m3
Comparing CNT springs performances with those of other technologies, they lag behind the energy
densities of rechargeable batteries.
The order of magnitude of CNT springs' energy densities is comparable with that of CAES, flywheels
and supercapacitors. Even if at an early stage, CNT springs have a power density that is comparable to
batteries.
3. Conclusion
Conventional mechanical springs coupled with electromechanical devices for energy storage and


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Soluble Salts
Soluble salts may accumulate on the top of the soil, forming a yellow or white crust. A ring of salt deposits may form around the pot at the soil line or around the drainage hole. Salts may also build up on the outside of clay pots. In house plants, signs of excess soluble salts include reduced growth, brown leaf tips, dropping of lower leaves, small new growth, dead root tips, and wilting.
Soluble salts are minerals dissolved in water. Fertilizer dissolved in water becomes a soluble salt. When water evaporates from the soil, the minerals or salts stay behind. As the salts in the soil become more and more concentrated, it becomes more difficult for plants to take up water. If salts build up to an extremely high level, water can be taken out of the root tips, causing them to die. High levels of soluble salts damage the roots directly, weakening the plant and making it more susceptible to attack from insects and diseases. One of the most common problems associated with high salt levels is root rot.
The best way to prevent soluble salt injury is to stop the salts from building up. When watering, allow some water to drain through the container and then empty the saucer. Do not allow the pot to sit in water. If the drained water is absorbed by the soil, the salts that were washed out are reabsorbed through the drainage hole or directly through a clay pot.
House plants should be leached at least every 4 to 6 months. To leach plants, pour excess water on the soil and let it drain completely. The amount of water used for leaching should equal twice the volume of the pot. Keep the water running through the soil to wash out the salts. If a layer of salts has formed a crust at the soil surface, remove the salt crust before leaching. Do not remove more than 1/4 inch (6 mm) of soil. It is best not to add soil to the top of the pot. If the soluble salt level appears to be extremely high, repot the plant.


The level of salts that causes injury varies with the species of plant and how it is grown. A house plant may be injured by salts at a very low concentration, but the same plant growing in a greenhouse where watering is well managed may tolerate salts at high levels. Some nurseries and retail plant outlets leach plants to remove excess salts before the plant is sold. If you are not sure that a newly purchased plant has been leached, leach it the first time you water.
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# Ceramics
Ceramics are a confusing issue. Are they like glass? Actually they aren't,
because they don't melt. Are they organic, so they can be composted? No again!
So they end up in garbage where their sharp corners are a danger, then in
dumps, which is a waste and a shame.
A ceramic is most often made from clay that has been heated to where the
particles partially melt together (sinter) and stick together into a rigid
mass. The way to reuse a broken ceramic mass is thus obvious. Break the
particles apart and return them to the clay that they were made from. This is
best done by grinding the pieces in a mill, but second best would be simply
breaking the large pieces into powder with a large hammer or a flat tamping
tool. The powder may not be valuable, since it is just ordinary clay, but at
least it can be distributed onto soil with no ill effect and it is not filling
up dumps. Some excessively sandy soils may benefit from the addition of clay
powder.
Some ceramics, known as refractories, usually found in high tech or research
ceramics, may be made from valuable or rare oxides, or even highly refined
aluminum oxides (claylike) rather than simple clay. Recapturing the powder may
be economically worthwhile.
Using a personal hammer for smashing broken teapots or flowerpots is
satisfying but is not a large scale solution for society. What we need is a
dedicated grinding mill that takes in all of a population's broken ceramics
and puts them through a power mill. Then the amount of powder would be
significant and could be reused for new ceramics. More research would be
useful, since not all ceramics are the same and they often have glazes.
One ceramic that is common and a bit valuable is porcelain which is made from
a fine, white clay. There is a ton of this available from unwanted toilets and
sinks. One tile maker in San Jose California makes a good living by milling
bathroom fixtures back into clay and then remaking them as exquisite tiles.
Read more.


Are banana peels higher in potassium and magnesium than the fruit itself?
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Assistant
·
Bot
Banana peels do contain higher amounts of potassium and magnesium compared to the fruit itself. While the peel is not typically consumed, it does have nutritional benefits. However, it\'s important to note that the peel also contains more fiber and other compounds that may not be as palatable as the fruit.
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Dan Hauenstein
Studied Biology at College of Lake County
·
4y
Bananas contain a plethora of nutrients, including Vitamin B6, Manganese, Vitamin C, Magnesium and a huge amount of potassium. The peel is edible and consumed in many cultures. The peel has a lot of the nutrients the rest of the fruit has, but the inside of the fruit still contains more potassium than the peel. The average banana contains a whopping 422mg of potassium and the peel contains about 78mg.


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Related questions
How many bananas can I eat to get full magnesium?
Do bananas contain magnesium?
Which food contains a higher amount of magnesium, banana or avocado?
Which fruit has the most potassium and magnesium?
Are banana peels good for plants?
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Shilpa Sadhaa
Studied Nutrition & YogaAuthor has 370 answers and 230K answer views
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1y
Related
What minerals and vitamines does a banana/peel have the most of?
The banana peels themselves offer additional nutrients, including:
Vitamin B6.
Vitamin B12.
Magnesium.
Potassium.
Fiber.
Protein.
Banana peels are rich in polyphenols, carotenoids, and other antioxidants that protect your body from cancer-causing free radicals. Consuming more banana peels can boost your antioxidant levels and lower your chance of developing cancer.
Banana peel also contains vitamins C, E, and B6. Vitamin C can act as an antioxidant, while serotonin is thought to play an anti-depressant so as to increase feed intake and body weight on heat stress conditions.
The banana peel is rich in protein, dietary fiber, vitamin C, vitamin A, calcium, iron, essential amino acids, polyunsaturated fatty acids, antioxidants and potassium.
If you\'ve been wondering if you can eat raw, cooked or even frozen banana peels, the answer is yes! If you are going to eat your banana peel, know that---just like the fruit itself---the riper the peel, the sweeter it will taste.
While this is not much of a concern if you\'re only eating the fruit, it may be something to consider when consuming the peel. Pesticide exposure has been linked to several adverse effects on health and may increase the risk of conditions like autism, cancer, high blood pressure, diabetes, and dementia.


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Boris Zakharin
loves scienceAuthor has 3.8K answers and 2.4M answer views
·
4y
There are plenty of articles claiming that banana peels are full of nutrients, and that people all over the world eat banana peels together with the flesh. While the peels really do contain nutrients, there have been no studies about how efficiently these nutrients are absorbed by the body, if at all. There have also been no legitimately documented cultures where banana peel eating is widespread. In fact, even monkeys peel bananas before eating them.
That said, aside for potential pesticides sprayed on them, banana peels are not harmful to eat, just bitter and unpleasant, so those who want to t
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Dr. Gennifer Herley
MD Student at Yale School of Medicine (2021--present)Author has 497 answers and 351.2K answer views
·
6mo
Related
Is banana content magnesium?
In the world of health and nutrition, one question that often arises is, \"Is banana content magnesium?\" Bananas are a beloved fruit enjoyed by people all around the globe, and their nutritional value is a topic of interest for many. In this comprehensive article, we will delve into the composition of bananas, exploring whether they contain magnesium and what implications this has for your health.
The Nutritional Powerhouse: Bananas
Bananas are not only delicious but also pack a powerful nutritional punch. They are rich in essential vitamins and minerals that contribute to overall health and well


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Related questions
Are bananas a good source of magnesium?
How might I measure the amount of potassium in a banana?
The US RDA of potassium is 4700 mg. However it is a lot work to get this. What is the difference between eating 15 bananas as opposed to taking a couple of teaspoons of potassium citrate daily?
Is coconut water a better source of potassium and magnesium than bananas?
How many bananas do you have to eat to get your daily potassium?
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Mary
Bachelor\'s degree in history, Master\'s degree in cultural stAuthor has 1.5K answers and 4.5M answer views
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10mo
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Has there been any extensive research about the nutritional content of cavendish banana peels?
While bananas are a widely consumed fruit, the focus of nutritional research has primarily been on the edible portion---the flesh of the banana---rather than the peel. As a result, there is limited and extensive research specifically on the nutritional content of Cavendish banana peels.
However, it is known that banana peels contain certain nutrients and compounds. They are a source of dietary fiber, including both soluble and insoluble fiber, which can support digestive health. Additionally, banana peels contain various vitamins and minerals, such as vitamin C, vitamin B6, potassium, magnesium, and manganese, although the exact quantities may vary.
Some preliminary studies have explored the potential health benefits of consuming banana peels. These studies suggest that the peels may have antioxidant properties due to their content of phenolic compounds. Banana peels also contain compounds like dopamine and serotonin, which are associated with mood regulation and may have positive effects on mental well-being.


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Lucy Thompson
Lives in Jefferson City, MissouriAuthor has 2.3K answers and 1.7M answer views
·
2y
Related
How many milligrams of potassium are in each gram of banana peel?
The banana peel does have potassium as well as the banana fruit. There are wildly varying reports of the potassium content of banana peels, and some "organic gardeners" extoll the virtues of the high level of potassium in peels and use them for fertilizer championing the added potassium to their precious dirt. A couple of websites actually claim the banana peel is 42% potassium.
A "pretty good" average value for the amount of potassium in banana:
Fruit - 3.58 mg K per gm of banana fruit
Peel - 0.78 mg K per gm of banana peel
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§ 205.203 Soil fertility and crop nutrient management practice standard.
(a) The producer must select and implement tillage and cultivation practices that maintain or improve the physical, chemical, and biological condition of soil and minimize soil erosion.
(b) The producer must manage crop nutrients and soil fertility through rotations, cover crops, and the application of plant and animal materials.
(c) The producer must manage plant and animal materials to maintain or improve soil organic matter content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances. Animal and plant materials include:
(1) Raw animal manure, which must be composted unless it is:
(i) Applied to land used for a crop not intended for human consumption;
(ii) Incorporated into the soil not less than 120 days prior to the harvest of a product whose edible portion has direct contact with the soil surface or soil particles; or
(iii) Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible portion does not have direct contact with the soil surface or soil particles;
(2) Composted plant and animal materials produced through a process that:
(i) Established an initial C:N ratio of between 25:1 and 40:1; and
(ii) Maintained a temperature of between 131 °F and 170 °F for 3 days using an in-vessel or static aerated pile system; or
(iii) Maintained a temperature of between 131 °F and 170 °F for 15 days using a windrow composting system, during which period, the materials must be turned a minimum of five times.
(3) Uncomposted plant materials.
(d) A producer may manage crop nutrients and soil fertility to maintain or improve soil organic matter content in a manner that does not contribute to contamination of crops, soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances by applying:
(1) A crop nutrient or soil amendment included on the National List of synthetic substances allowed for use in organic crop production;
(2) A mined substance of low solubility;
(3) A mined substance of high solubility: Provided, That, the substance is used in compliance with the conditions established on the National List of nonsynthetic materials prohibited for crop production;
(4) Ash obtained from the burning of a plant or animal material, except as prohibited in paragraph (e) of this section: Provided, That, the material burned has not been treated or combined with a prohibited substance or the ash is not included on the National List of nonsynthetic substances prohibited for use in organic crop production; and
(5) A plant or animal material that has been chemically altered by a manufacturing process: Provided, That, the material is included on the National List of synthetic substances allowed for use in organic crop production established in § 205.601.
(e) The producer must not use:
(1) Any fertilizer or composted plant and animal material that contains a synthetic substance not included on the National List of synthetic substances allowed for use in organic crop production;
(2) Sewage sludge (biosolids) as defined in 40 CFR part 503; and
(3) Burning as a means of disposal for crop residues produced on the operation: Except, That, burning may be used to suppress the spread of disease or to stimulate seed germination.