Development and validation of models to predict personal ventilation rate for air pollution research.

Air pollution intake represents the amount of pollution inhaled into the body and may be calculated by multiplying an individual's ventilation rate with the concentration of pollutant present in their breathing zone. Ventilation rate is difficult to measure directly, and methods for estimating ventilation rate (and intake) are lacking. Therefore, the goal of this work was to examine how well linear models using heart rate and other basic physiologic data can predict personal ventilation rate. We measured personal ventilation and heart rate among a panel of subjects (n = 36) while they conducted a series of specified routine tasks of varying exertion levels. From these data, 136 candidate models were identified using a series of variable transformation and selection algorithms. A second "free­living" validation study (n = 26) served as an independent validation dataset for these candidate models. The top­performing model, which included heart rate (Hr), resting heart rate (Hrest), age, sex, and hip circumference and interactions between sex with Hr, Hrest, age, and hip predicted ventilation rate (Ve) to within 11% and 33% for moderate (Ve = 45 L/min) and low (Ve = 15 L/min) intensity activities, respectively, based on the validation study. Many of the promising candidate models performed substantially worse under independent validation. Our results indicate that while measures of air pollution exposure and intake are highly correlated within tasks for a given individual, this correlation decreases substantially across tasks (i.e., as individuals go about a series of typical daily activities). This discordance between exposure and intake may influence exposure­response estimates in epidemiological studies. New air pollution studies should consider the trade­offs between the predictive ability of intake models and the error potentially introduced by not accounting for ventilation rate.

Exposure to household air pollution from biomass-burning cookstoves and HbA1c and diabetic status among Honduran women.

Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middle-income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This cross-sectional study of 142 women (72 with traditional stoves and 70 with cleaner-burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24-hour average kitchen and personal fine particulate matter [PM2.5 ] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 µg/m3 increase in personal PM2.5 , 1.49; 95% confidence interval [CI], 1.11-2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated.

Impact of a cleaner-burning cookstove intervention on blood pressure in Nicaraguan women.

Few studies have evaluated the cardiovascular-related effects of indoor biomass burning or the role of characteristics such as age and obesity status, in this relationship. We examined the impact of a cleaner-burning cookstove intervention on blood pressure among Nicaraguan women using an open fire at baseline; we also evaluated heterogeneity of the impact by subgroups of the population. We evaluated changes in systolic and diastolic blood pressure from baseline to post-intervention (range: 273-383 days) among 74 female cooks. We measured indoor fine particulate matter (PM(2.5); N = 25), indoor carbon monoxide (CO; N = 32), and personal CO (N = 30) concentrations. Large mean reductions in pollutant concentrations were observed for all pollutants; for example, indoor PM(2.5) was reduced 77% following the intervention. However, pollution distributions (baseline and post-intervention) were wide and overlapping. Although substantial reductions in blood pressure were not observed among the entire population, a 5.9 mmHg reduction [95% confidence interval (CI): -11.3, -0.4] in systolic blood pressure was observed among women aged 40 or more years and a 4.6 mmHg reduction (95% CI: -10.0, 0.8) was observed among obese women. Results from this study provide an indication that certain subgroups may be more likely to experience improvements in blood pressure following a cookstove intervention.

Management and prevention of personal problems in older adolescents via schematic maps and peer feedback.

The purpose of the present study was to provide a basis for enhancing personal development in older adolescents by examining the usefulness of two information-processing tools in solving personal problems: schematic maps and peer feedback. Ninety-five college students were assigned to either a schematic map group or an essay group, and further subdivided into groups that worked alone or with a vicarious partner. Assessment consisted of analyzing and generating alternatives to a scenario involving a college student with a drinking problem. Results indicated that alternative generation, an important step in the problem-solving process, is susceptible to experimental manipulation. Schematic maps facilitate the generation of wider-ranging, viable, synergistic alternatives to an uncomfortable situation. Maps help illustrate the complex systems within which problems occur and how patterns of behavior are maintained through reinforcement. Peer feedback may provide information about strategies for the development of additional options.

Schematic maps: cognitive tools for enhancing the early stages of counseling.

The purpose of the present studies was to explore the utility of schematic maps as tools for the early stages of both peer and self-counseling. In experiment 1 (self-counseling), 42 students from undergraduate general psychology classes participated to fulfill course requirements. Participants were assigned to either a schematic map or essay group. They first extracted information about their alcohol-related behavior patterns and then analyzed the patterns from the perspective of a counselor. In experiment 2 (peer counseling), 38 students from upper-division psychology courses participated for extra credit. Participants were asked to evaluate behavior patterns, in the form of maps or essays, which were presented either in the same form as they were extracted or were transposed to the other format. In both studies, assessment consisted of questionnaires that addressed the usefulness of the tools in the counseling process. Schematic maps are potentially powerful tools for both self- and peer counseling. For self-counseling, maps were preferred over traditional essay writing. In addition, the subjective reaction to maps as tools for peer counseling was positive.

Using scripted cooperation to communicate information about the consequences of alcohol and cocaine use.

Fifty-two participants from undergraduate psychology classes at a private university were asked to study, either cooperatively or individually, information dealing with the consequences of using alcohol and cocaine. Objectives were to (a) determine the effect of cooperative study on recall, (b) assess personal reactions to the information presented, and (c) assess the effect of individual differences. Findings indicate that cooperative study can facilitate both recall of information as well as degree of understanding and confidence in dealing with persons using alcohol/cocaine; that the materials used were received positively; and that verbal ability may play a subtle role in college students' responses to alcohol/cocaine information.

Identifying the best scenario for using schematic organizers as integration tools for alcohol-related information.

The goal of the present study was to examine scenarios for using two schematic organizers--schematic knowledge maps and conceptual matrices--in integrating episodic and semantic knowledge about alcohol. Seventy students from undergraduate general psychology classes participated for course credit. Participants were assigned to either a schematic organizer group or an essay writing group. These groups were subdivided further into two treatment sequences: episodic/semantic and semantic/episodic. The episodic activity required participants to complete materials using their own alcohol-related experiences, whereas the semantic activity required participants to annotate expert materials. Assessment measures used were consumer-satisfaction questionnaires and free-recall tests. While no preferences were established for any one scenario, the episodic activities were rated higher than the semantic activities regardless of integration sequence. The semantic/episodic integration scenario did produce higher recall scores for the expert information.

Using knowledge maps and scripted cooperation to inform college students about patterns of behavior related to recurring abuse of alcohol.

Objectives of this study were to determine the effectiveness of using a specific information format--graphic representations called knowledge maps--and an information processing strategy--scripted cooperation--in teaching college students about behavior patterns that underlie recurring abuse of alcohol. Participants in this three-session, 6-hour study were 111 Texas Christian University students recruited from undergraduate psychology classes. Participants were randomly assigned to one of two materials format conditions (map vs. text format) and to one of two processing strategy conditions (individual processing vs. scripted interaction with a partner). Results indicate that map format facilitated recall of the pattern information; processing with a partner appeared to enhance perception of the multidimensional nature of behavior that supports alcohol use.

Using conceptual matrices, knowledge maps, and scripted cooperation to improve personal management strategies.

Research in the area of substance abuse suggests that ineffective personal management strategies appear to be a major factor in abuse behavior. In this study, fifty-seven students in an intermediate level psychology class were provided with three tools previously found to enhance academic learning strategies--knowledge maps, scripted peer cooperation, and conceptual matrices--as a means of understanding and improving personal management strategies. Student ratings of the value of these activities were significantly higher than an average or moderate response. Individual differences appear to be an important consideration in predicting participants' perceptions of the value of this approach. Those who felt they had control of whatever happens to them, and those who perceived problems as impactful and had strong desires to change recurring problem situations, had the most positive reactions to the types of activities used in this study.

Scopolamine produces locomotor stereotypy in an open field but apomorphine does not.

Both dopaminergic and nondopaminergic drugs produce hyperlocomotion in rats. Dopaminergic drugs also produce focused stereotypy (absence of locomotion and intense sniffing or licking/biting of a restricted area of the environment). Some drugs produce repetitive routes of locomotion; this phenomenon might represent a combination of hyperlocomotion and stereotypy. Scopolamine (an acetylcholine antagonist) and apomorphine (a dopamine agonist) both produce hyperlocomotion in rats; apomorphine also produces focused stereotypy but scopolamine does not. This research determines whether these drugs also produce locomotor stereotypy as measured by gamma. Scopolamine (0.5 and 2.0 mg/kg) produced locomotor stereotypy at both doses. Apomorphine (1.0, 2.0, and 3.0 mg/kg) failed to reliably produce locomotor stereotypy. Thus, there is not necessarily a relationship between the ability of a drug to produce focused stereotypy and the ability of the drug to produce locomotor stereotypy.

Effects of caerulein + haloperidol on amphetamine-induced locomotor stereotypy in rats.

The combination of haloperidol + caerulein has been reported to produce a long-lasting reduction of amphetamine-induced hyperlocomotions in rats. This study was designed to replicate those findings and to determine whether haloperidol + caerulein produce any unique effect on amphetamine-induced locomotor stereotypy. In two experiments, haloperidol + caerulein failed to produce a long-lasting reduction in amphetamine-induced hyperlocomotions. Although haloperidol reduced the locomotor stereotypy produced by higher doses of amphetamine, caerulein had no effect, either alone or combined with haloperidol.

Streptococcus pleomorphus sp.nov.: an anaerobic streptococcus isolated mainly from the caeca of birds.

A new species Streptococcus pleomorphus is described. It is obligately anaerobic and classified in the genus Streptococcus because it is a Gram-positive coccus growing in pairs and chains, with a homolactic fermentation of glucose producing L-lactic acid. The GC content of the DNA is 39 mol%. The organism has been mainly isolated from chickens, turkeys and ducks.

The biosynthesis of valine from isobutyrate by peptostreptococcus elsdenii and Bacteroides ruminicola.

1. Growing cultures of Peptostreptococcus elsdenii and Bacteroides ruminicola incorporate (14)C from [1-(14)C]isobutyrate into the valine of cell protein. With P. elsdenii some of the (14)C is also incorporated into leucine. 2. Crude cell-free extracts of both organisms in the presence of glutamine, carbon dioxide and suitable sources of energy and electrons incorporate (14)C from [1-(14)C]isobutyrate into valine but not into leucine. 3. With extracts of P. elsdenii treated with DEAE-cellulose the reaction is dependent on ATP, CoA, thiamin pyrophosphate, molecular hydrogen and a low-potential electron carrier (ferredoxin, flavodoxin or benzyl viologen). 4. The same extracts incorporate (14)C from NaH(14)CO(3) into valine in the presence of isobutyrate plus ATP, CoA, glutamine and ferredoxin; isobutyryl-CoA or isobutyryl phosphate plus CoA will replace the isobutyrate plus CoA and ATP. With acetyl phosphate in place of isobutyryl phosphate, (14)C is incorporated into alanine. With isovalerate or 2-methylbutyrate in place of isobutyrate, (14)C is incorporated into leucine and isoleucine respectively. 5. When carrier 2-oxoisovalerate is added to the carboxylating system (14)C from [1-(14)C]isobutyrate passes into the oxo acid fraction. 6. It is concluded that these two organisms form valine from isobutyrate by the sequence isobutyrate-->isobutyryl-CoA-->2-oxoisovalerate-->valine and that the reductive carboxylation of isobutyrate is catalysed by a system similar to the pyruvate synthetase of clostridia and photosynthetic bacteria.

Biosynthesis of amino acids in Clostridium pasteurianum.

1. Clostridium pasteurianum was grown on a synthetic medium with the following carbon sources: (a) (14)C-labelled glucose, alone or with unlabelled aspartate or glutamate, or (b) unlabelled glucose plus (14)C-labelled aspartate, glutamate, threonine, serine or glycine. The incorporation of (14)C into the amino acids of the cell protein was examined. 2. In both series of experiments carbon from exogenous glutamate was incorporated into proline and arginine; carbon from aspartate was incorporated into glutamate, proline, arginine, lysine, methionine, threonine, isoleucine, glycine and serine. Incorporations from the other exogenous amino acids indicated the metabolic sequence: aspartate --> threonine --> glycine right harpoon over left harpoon serine. 3. The following activities were demonstrated in cell-free extracts of the organism: (a) the formation of aspartate by carboxylation of phosphoenolpyruvate or pyruvate, followed by transamination; (b) the individual reactions of the tricarboxylic acid route to 2-oxoglutarate from oxaloacetate; glutamate dehydrogenase was not detected; (c) the conversion of aspartate into threonine via homoserine; (d) the conversion of threonine into glycine by a constitutive threonine aldolase; (e) serine transaminase, phosphoserine transaminase, glycerate dehydrogenase and phosphoglycerate dehydrogenase. This last activity was abnormally high. 4. The combined evidence indicates that in C. pasteurianum the biosynthetic role of aspartate and glutamate is generally similar to that in aerobic and facultatively aerobic organisms, but that glycine is synthesized from glucose via aspartate and threonine.