Stability analysis of a continuous stirred tank reactor with an autocatalytic reaction

The basic principles of stability analysis are set forth, including the development of a mathematical model, steady state analysis, integration of the dynamic system equations, and predictions of transient responses. The equations for the mathematical model are developed for a continuous stirred tank reactor with a cooling jacket, containing an autocatalytic reaction, in unsteady state operation. These equations are numerically integrated to obtain a good picture of reactor dynamics about the steady state. State variable methods, including the classical linearization theorems and Lyapunov\u27s Second Method, are utilized to predict bounds of stable reactor behavior. A discussion of the shortcomings of each method is presented. Finally the results are compared and recommendations are set forth

Field and laboratory studies reveal interacting effects of stream oxygenation and warming on aquatic ectotherms

Aquatic ecological responses to climatic warming are complicated by interactions between thermal effects and other environmental stressors such as organic pollution and hypoxia. Laboratory experiments have demonstrated how oxygen limitation can set heat tolerance for some aquatic ectotherms, but only at unrealistic lethal temperatures and without field data to assess whether oxygen shortages might also underlie sublethal warming effects. Here, we test whether oxygen availability affects both lethal and nonlethal impacts of warming on two widespread Eurasian mayflies, Ephemera danica, Müller 1764 and Serratella ignita (Poda 1761). Mayfly nymphs are often a dominant component of the invertebrate assemblage in streams, and play a vital role in aquatic and riparian food webs. In the laboratory, lethal impacts of warming were assessed under three oxygen conditions. In the field, effects of oxygen availability on nonlethal impacts of warming were assessed from mayfly occurrence in 42 293 UK stream samples where water temperature and biochemical oxygen demand were measured. Oxygen limitation affected both lethal and sublethal impacts of warming in each species. Hypoxia lowered lethal limits by 5.5 °C (±2.13) and 8.2 °C (±0.62) for E. danica and S. ignita respectively. Field data confirmed the importance of oxygen limitation in warmer waters; poor oxygenation drastically reduced site occupancy, and reductions were especially pronounced under warm water conditions. Consequently, poor oxygenation lowered optimal stream temperatures for both species. The broad concordance shown here between laboratory results and extensive field data suggests that oxygen limitation not only impairs survival at thermal extremes but also restricts species abundance in the field at temperatures well below upper lethal limits. Stream oxygenation could thus control the vulnerability of aquatic ectotherms to global warming. Improving water oxygenation and reducing pollution can provide key facets of climate change adaptation for running waters

Missing the forest (plot) for the trees? A critique of the systematic review in tobacco control

<p>Abstract</p> <p>Background</p> <p>The systematic review (SR) lies at the core of evidence-based medicine. While it may appear that the SR provides a reliable summary of existing evidence, standards of SR conduct differ. The objective of this research was to examine systematic review (SR) methods used by the Cochrane Collaboration ("<it>Cochrane</it>") and the Task Force on Community Preventive Services ("the <it>Guide</it>") for evaluation of effectiveness of tobacco control interventions.</p> <p>Methods</p> <p>We searched for all reviews of tobacco control interventions published by Cochrane (4^thquarter 2008) and the <it>Guide</it>. We recorded design rigor of included studies, data synthesis method, and setting.</p> <p>Results</p> <p>About a third of the Cochrane reviews and two thirds of the Guide reviews of interventions in the community setting included uncontrolled trials. Most (74%) Cochrane reviews in the clinical setting, but few (15%) in the community setting, provided pooled estimates from RCTs. Cochrane often presented the community results narratively. The Guide did not use inferential statistical approaches to assessment of effectiveness.</p> <p>Conclusions</p> <p>Policy makers should be aware that SR methods differ, even among leading producers of SRs and among settings studied. The traditional SR approach of using pooled estimates from RCTs is employed frequently for clinical but infrequently for community-based interventions. The common lack of effect size estimates and formal tests of significance limit the contribution of some reviews to evidence-based decision making. Careful exploration of data by subgroup, and appropriate use of random effects models, may assist researchers in overcoming obstacles to pooling data.</p

Effects of achievement goals on perceptions of competence in conditions of unfavourable social comparisons: The mastery goal advantage effect

Background: Previous prospective studies have documented that mastery-approach goals are adaptive because they facilitate less negative psychological responses to unfavourable social comparisons than performance-approach goals. AIMS: This study aimed to confirm this so-called 'mastery goal advantage' effect experimentally. Methods: A 2 × 3 design was adopted where achievement goals (mastery vs. performance) and normative information (favourable vs. no-normative information vs. unfavourable) were manipulated as between participant factors. Sample: Participants were 201 undergraduates, 57 males and 144 females, ranging in age from 17 to 55 years (Mage = 22.53, SD = 6.51). Results: Regression analyses pointed out that experimentally induced mastery-approach goals facilitated higher levels of competence and happiness with task performance than experimentally induced performance-approach goals in conditions of unfavourable social comparisons. In contrast, although performance-approach goals yielded the highest levels of happiness with task performance in conditions of favourable social comparisons, this positive effect of performance-approach goals did not extend to perceptions of competence. Conclusion: Current findings broaden understanding of the adaptive nature of mastery-approach goals and suggest that it is possible to modulate aversive responses to unfavourable social comparisons by focusing attention on mastery-approach goals

Recommendations for Meeting the Pediatric Patient's Need for a Clinical Pharmacist: A Joint Opinion of the Pediatrics Practice and Research Network of the American College of Clinical Pharmacy and the Pediatric Pharmacy Advocacy Group

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96318/1/phar1246.pd

Reading Self-Efficacy Predicts Word Reading But Not Comprehension in Both Girls and Boys

The relationship between cognitive skills and reading has been well-established. However, the role of motivational factors such as self-efficacy in reading progress is less clear. In particular, it is not clear how self-efficacy relates to word level reading versus comprehension, and whether this differs in boys and girls. This study examines the relationship between self-efficacy, word reading and reading comprehension across the range of reading abilities after controlling for reading-related cognitive factors. One hundred and seventy nine children (86 males and 93 females) between 8 and 11 years old completed a self-report measure of reading self-efficacy together with measures of reading comprehension and word reading, working memory, auditory short-term memory, phonological awareness, and vocabulary. Boys and girls showed similar levels of attainment and reading self-efficacy. Reading self-efficacy was associated with word reading, but not with reading comprehension in either boys or girls. It is argued that this may reflect important differences between reading self-efficacy and more general measures of reading motivation and engagement. Reading self-efficacy is an element of reading motivation that is closely associated with a child’s perceived attainments in reading and is less susceptible to the gender differences seen in broader measures

Bacterial biogeography of adult airways in atopic asthma

Abstract Background Perturbations to the composition and function of bronchial bacterial communities appear to contribute to the pathophysiology of asthma. Unraveling the nature and mechanisms of these complex associations will require large longitudinal studies, for which bronchoscopy is poorly suited. Studies of samples obtained by sputum induction and nasopharyngeal brushing or lavage have also reported asthma-associated microbiota characteristics. It remains unknown, however, whether the microbiota detected in these less-invasive sample types reflect the composition of bronchial microbiota in asthma. Results Bacterial microbiota in paired protected bronchial brushings (BB; n = 45), induced sputum (IS; n = 45), oral wash (OW; n = 45), and nasal brushings (NB; n = 27) from adults with mild atopic asthma (AA), atopy without asthma (ANA), and healthy controls (HC) were profiled using 16S rRNA gene sequencing. Though microbiota composition varied with sample type (p < 0.001), compositional similarity was greatest for BB-IS, particularly in AAs and ANAs. The abundance of genera detected in BB correlated with those detected in IS and OW (r median [IQR] 0.869 [0.748–0.942] and 0.822 [0.687–0.909] respectively), but not with those in NB (r = 0.004 [− 0.003–0.011]). The number of taxa shared between IS-BB and NB-BB was greater in AAs than in HCs (p < 0.05) and included taxa previously associated with asthma. Of the genera abundant in NB, only Moraxella correlated positively with abundance in BB; specific members of this genus were shared between the two compartments only in AAs. Relative abundance of Moraxella in NB of AAs correlated negatively with that of Corynebacterium but positively with markers of eosinophilic inflammation in the blood and BAL fluid. The genus, Corynebacterium, trended to dominate all NB samples of HCs but only half of AAs (p = 0.07), in whom abundance of this genus was negatively associated with markers of eosinophilic inflammation. Conclusions Induced sputum is superior to nasal brush or oral wash for assessing bronchial microbiota composition in asthmatic adults. Although compositionally similar to the bronchial microbiota, the microbiota in induced sputum are distinct, reflecting enrichment of oral bacteria. Specific bacterial genera are shared between the nasal and the bronchial mucosa which are associated with markers of systemic and bronchial inflammation.https://deepblue.lib.umich.edu/bitstream/2027.42/144218/1/40168_2018_Article_487.pd

A framework for developing an evidence-based, comprehensive tobacco control program

BACKGROUND: Tobacco control is an area where the translation of evidence into policy would seem to be straightforward, given the wealth of epidemiological, behavioural and other types of research available. Yet, even here challenges exist. These include information overload, concealment of key (industry-funded) evidence, contextualization, assessment of population impact, and the changing nature of the threat. METHODS: In the context of Israel's health targeting initiative, Healthy Israel 2020, we describe the steps taken to develop a comprehensive tobacco control strategy. We elaborate on the following: a) scientific issues influencing the choice of tobacco control strategies; b) organization of existing evidence of effectiveness of interventions into a manageable form, and c) consideration of relevant philosophical and political issues. We propose a framework for developing a plan and illustrate this process with a case study in Israel. RESULTS: Broad consensus exists regarding the effectiveness of most interventions, but current recommendations differ in the emphasis they place on different strategies. Scientific challenges include integration of complex and sometimes conflicting information from authoritative sources, and lack of estimates of population impact of interventions. Philosophical and political challenges include the use of evidence-based versus innovative policymaking, the importance of individual versus governmental responsibility, and whether and how interventions should be prioritized.The proposed framework includes: 1) compilation of a list of potential interventions 2) modification of that list based on local needs and political constraints; 3) streamlining the list by categorizing interventions into broad groupings of related interventions; together these groupings form the basis of a comprehensive plan; and 4) refinement of the plan by comparing it to existing comprehensive plans. CONCLUSIONS: Development of a comprehensive tobacco control plan is a complex endeavour, involving crucial decisions regarding intervention components. "Off the shelf" plans, which need to be adapted to local settings, are available from a variety of sources, and a multitude of individual recommendations are available. The proposed framework for adapting existing approaches to the local social and political climate may assist others planning for smoke-free societies. Additionally, this experience has implications for development of evidence-based health plans addressing other risk factors