No evidence for UV-based nest-site selection in sticklebacks

BACKGROUND: Nests are built in various animal taxa including fish. In systems with exclusive male parental care, the choice of a nest site may be an important component of male fitness. The nest site may influence male attractiveness as a mate, and male, embryo, and juvenile survival probabilities. Reproductively active three-spined stickleback males establish and defend a territory in which they build a nest. Territories can differ remarkably in qualities that influence male and female reproductive success like predation risk or abiotic factors such as dissolved oxygen concentration or lighting conditions. The latter may be important because in sticklebacks the extended visual capability into the ultraviolet (UV) wave range plays a role in female mate choice. Males are thus expected to be choosy about the habitat in which they will build their nest. RESULTS: We tested nest-site choice in male three-spined sticklebacks with respect to different UV lighting conditions. Reproductively active males were given the simultaneous choice to build their nest either in an UV-rich (UV+) or an UV-lacking (UV-) environment. Males exhibited no significant nest-site preferences with respect to UV+ or UV-. However, larger males and also heavier ones completed their nests earlier. CONCLUSION: We found that UV radiation as well as differences in luminance had no influence on nest-site choice in three-spined sticklebacks. Males that built in the UV-rich environment were not different in any trait (body traits and UV reflection traits) from males that built in the UV-poor environment. There was a significant effect of standard length and body mass on the time elapsed until nest completion in the UV experiment. The larger and heavier a male, the faster he completed his nest. In the brightness control experiment there was a significant effect only of body mass on the duration of nest completion. Whether nest building preferences with respect to UV lighting conditions are context dependent needs to be tested for instance by nest-site choice experiment under increased predation risk

Metabolic compartmentalization in the human cortex and hippocampus: evidence for a cell- and region-specific localization of lactate dehydrogenase 5 and pyruvate dehydrogenase

BACKGROUND: For a long time now, glucose has been thought to be the main, if not the sole substrate for brain energy metabolism. Recent data nevertheless suggest that other molecules, such as monocarboxylates (lactate and pyruvate mainly) could be suitable substrates. Although monocarboxylates poorly cross the blood brain barrier (BBB), such substrates could replace glucose if produced locally.The two key enzymatiques systems required for the production of these monocarboxylates are lactate dehydrogenase (LDH; EC1.1.1.27) that catalyses the interconversion of lactate and pyruvate and the pyruvate dehydrogenase complex that irreversibly funnels pyruvate towards the mitochondrial TCA and oxydative phosphorylation. RESULTS: In this article, we show, with monoclonal antibodies applied to post-mortem human brain tissues, that the typically glycolytic isoenzyme of lactate dehydrogenase (LDH-5; also called LDHA or LDHM) is selectively present in astrocytes, and not in neurons, whereas pyruvate dehydrogenase (PDH) is mainly detected in neurons and barely in astrocytes. At the regional level, the distribution of the LDH-5 immunoreactive astrocytes is laminar and corresponds to regions of maximal 2-deoxyglucose uptake in the occipital cortex and hippocampus. In hippocampus, we observed that the distribution of the oxidative enzyme PDH was enriched in the neurons of the stratum pyramidale and stratum granulosum of CA1 through CA4, whereas the glycolytic enzyme LDH-5 was enriched in astrocytes of the stratum moleculare, the alveus and the white matter, revealing not only cellular, but also regional, selective distributions. The fact that LDH-5 immunoreactivity was high in astrocytes and occurred in regions where the highest uptake of 2-deoxyglucose was observed suggests that glucose uptake followed by lactate production may principally occur in these regions. CONCLUSION: These observations reveal a metabolic segregation, not only at the cellular but also at the regional level, that support the notion of metabolic compartmentalization between astrocytes and neurons, whereby lactate produced by astrocytes could be oxidized by neurons

A study to explore if dentists’ anxiety affects their clinical decision-making

Aims To develop a measure of dentists’ anxiety in clinical situations; to establish if dentists’ anxiety in clinical situations affected their self-reported clinical decision-making; to establish if occupational stress, as demonstrated by burnout, is associated with anxiety in clinical situations and clinical decision-making; and to explore the relationship between decision-making style and the clinical decisions which are influenced by anxiety. Design Cross-sectional study. Setting Primary Dental Care. Subjects and methods A questionnaire battery [Maslach Burnout Inventory, measuring burnout; Melbourne Decision Making Questionnaire, measuring decision-making style; Dealing with Uncertainty Questionnaire (DUQ), measuring coping with diagnostic uncertainty; and a newly designed Dentists’ Anxieties in Clinical Situations Scale, measuring dentists’ anxiety (DACSS-R) and change of treatment (DACSS-C)] was distributed to dentists practicing in Nottinghamshire and Lincolnshire. Demographic data were collected and dentists gave examples of anxiety-provoking situations and their responses to them. Main outcome measure Respondents’ self-reported anxiety in various clinical situations on a 11-point Likert Scale (DACSS-R) and self-reported changes in clinical procedures (Yes/No; DACSS-C). The DACSS was validated using multiple t-tests and a principal component analysis. Differences in DACSS-R ratings and burnout, decision-making and dealing with uncertainty were explored using Pearson correlations and multiple regression analysis. Qualitative data was subject to a thematic analysis. Results The DACSS-R revealed a four-factor structure and had high internal reliability (Cronbach’s α = 0.94). Those with higher DACSS-R scores of anxiety were more likely to report changes in clinical procedures (DACSS-C scores). DACSS-R scores were associated with decision-making self-esteem and style as measured by the MDMQ and all burnout subscales, though not with scores on the DUQ scale. Conclusion Dentists’ anxiety in clinical situations does affect the way that dentists work clinically, as assessed using the newly designed and validated DACSS. This anxiety is associated with measures of burnout and decision-making style with implications for training packages for dentists

A study to explore specific stressors and coping strategies in primary dental care practice

Background and Aims: It is widely acknowledged that dentists experience occupational stress. This qualitative study aimed to explore previously identified specific stressors in more detail in order to inform the development of a future stress management programme. Method: Two focus groups of dentists (N: 7 & 6) were conducted to explore, in more detail, nine specific stressors and concepts; being out of one’s comfort zone, zoning out from the patient, celebrating the positive aspects of work, thinking aloud, the effect of hurting patients, the impact of perfectionism, responsibility for patient’s self-care, the emotional impact of difficult situations as a foundation dentist. Participants were also asked for their views on the structure and contents of the proposed stress management package. Verbatim transcripts were subjected to thematic analysis. Results and Discussion: Dentists described the impact of these stressors and their current coping methods; thematic analysis revealed 9 themes which covered the above concepts and a further overall theme of need for control. The findings are elaborated in connection to their relevant stress, coping and emotion psychological theory. Their implications for personal well-being and clinical outcomes are discussed. Conclusion: Dentists’ stressful and coping experiences are complex and it is essential that any stress management programme reflects this and that the skills are easily accessible and sustainable within the context of a busy dental practice

Reduction of Severe Acute Maternal Morbidity and Maternal Mortality in Thyolo District, Malawi: The Impact of Obstetric Audit

BACKGROUND: Critical incident audit and feedback are recommended interventions to improve the quality of obstetric care. To evaluate the effect of audit at district level in Thyolo, Malawi, we assessed the incidence of facility-based severe maternal complications (severe acute maternal morbidity (SAMM) and maternal mortality) during two years of audit and feedback. METHODOLOGY/PRINCIPAL FINDINGS: Between September 2007 and September 2009, we included all cases of maternal mortality and SAMM that occurred in Thyolo District Hospital, the main referral facility in the area, using validated disease-specific criteria. During two- to three-weekly audit sessions, health workers and managers identified substandard care factors. Resulting recommendations were implemented and followed up. Feedback was given during subsequent sessions. A linear regression analysis was performed on facility-based severe maternal complications. During the two-year study period, 386 women were included: 46 died and 340 sustained SAMM, giving a case fatality rate of 11.9%. Forty-five cases out of the 386 inclusions were audited in plenary with hospital staff. There was a reduction of 3.1 women with severe maternal complications per 1000 deliveries in the district health facilities, from 13.5 per 1000 deliveries in the beginning to 10.4 per 1000 deliveries at the end of the study period. The incidence of uterine rupture and major obstetric hemorrhage reduced considerably (from 3.5 to 0.2 and from 5.9 to 2.6 per 1000 facility deliveries respectively). CONCLUSIONS: Our findings indicate that audit and feedback have the potential to reduce serious maternal complications including maternal mortality. Complications like major hemorrhage and uterine rupture that require relatively straightforward intrapartum emergency management are easier to reduce than those which require uptake of improved antenatal care (eclampsia) or timely intravenous medication or HIV-treatment (peripartum infections)

Extreme genetic fragility of the HIV-1 capsid

Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

Clinical pharmacology of exogenously administered alkaline phosphatase

Purpose: To evaluate the clinical pharmacology of exogenous alkaline phosphatase (AP). Methods: Randomized, double-blind, placebo-controlled sequential protocols of (1) ascending doses and infusion duration (volunteers) and (2) fixed dose and duration (patients) were conducted at clinical pharmacology and intensive care units. A total of 103 subjects (67 male volunteers and 36 patients with severe sepsis) were administered exogenous, 10-min IV infusions (three ascending doses) or 24-72 h continuous (132.5-200 U kg-124 h-1) IV infusion with/without preceding loading dose and experimental endotoxemia for evaluations of pharmacokinetics, pharmacodynamics, safety parameters, antigenicity, inflammatory markers, and outcomes. Results: Linearity and dose-proportionality were shown during 10-min infusions. The relatively short elimination half-life necessitated a loading dose to achieve stable enzyme levels. Pharmacokinetic parameters in volunteers and patients were similar. Innate immunity response was not significantly influenced by AP, while renal function significantly improved in sepsis patients. Conclusions: The pharmacokinetics of exogenous AP is linear, dose-proportional, exhibit a short half-life, and are not influenced by renal impairment or dialysis

Association Between Statin Use and Prevalence of Exercise-Related Injuries: A Cross-Sectional Survey of Amateur Runners in the Netherlands.

BACKGROUND: HMG-CoA reductase inhibitors (statins) are the first-choice therapy for primary prevention of cardiovascular disease. Some maintain that statins cause adverse musculoskeletal outcomes in highly active individuals, but few studies have examined the effects of statins on exercise-related injuries. OBJECTIVE: We sought to compare the prevalence of exercise-related injuries between runners who do or do not use statins. METHODS: Amateur runners (n = 4460) completed an extensive online questionnaire on their exercise patterns and health status. Participants replied to questions on the prevalence of exercise-related injuries in the previous year. Injuries were divided into general injuries, tendon- and ligament-related injuries, and muscle-related injuries. Participants were also queried about statin use: the type of statin, statin dose, and duration of treatment. Runners were divided into statin users, non-statin users with hypercholesterolemia, and controls for analysis. RESULTS: The crude odds ratios (ORs) for injuries, tendon- or ligament-related injuries, and muscle-related injuries in statin users compared with controls were 1.14 (95% confidence interval [CI] 0.79-1.66), 1.10 (95% CI 0.71-1.72), and 1.15 (95% CI 0.69-1.91), respectively. After adjustment for age, sex, body mass index (BMI), and metabolic equivalent of task (MET) h/week of exercise, the ORs were 1.11 (95% CI 0.76-1.62), 1.06 (95% CI 0.68-1.66), and 0.98 (95% CI 0.58-1.64), respectively. Similar effect measures were found when comparing non-statin users with hypercholesterolemia and controls. CONCLUSION: We did not find an association between statin use and the prevalence of exercise-related injuries or tendon-, ligament-, and muscle-related injuries. Runners receiving statins should continue normal physical activity without concern for increased risk of injuries

Teacher Wellbeing: The Importance of Teacher–Student Relationships

Many studies have examined the importance of teacher-student relationships for the development of children. Much less is known, however, about how these relationships impact the professional and personal lives of teachers. This review considers the importance of teacher-student relationships for the wellbeing of teachers guided by the Transactional Model of Stress and Coping of Lazarus (1991). Based on theories on interpersonal relationships, it is postulated that teachers have a basic need for relatedness with the students in their class that originates from the close proximity between teacher and student. It is discussed that teachers internalize experiences with students in representational models of relationships that guide emotional responses in daily interactions with students, and changes teacher wellbeing in the long run. In addition, the notion of mental representations of relationships at different levels of generalization could offer a window to understand how individual teacher-student relationships may affect the professional and personal self-esteem of teachers. Lastly, it is argued that the influence of student misbehavior on teacher stress may be more fully understood from a relationship perspective. The review shows that few studies have directly tested these propositions and offers suggestions for future research