The Impact of Effect Size Heterogeneity on Meta-Analysis: A Monte Carlo Experiment

In this paper we use Monte Carlo simulation to investigate the impact of effect size heterogeneity on the results of a meta-analysis. Specifically, we address the small sample behaviour of the OLS, the fixed effects regression and the mixed effects meta-estimators under three alternative scenarios of effect size heterogeneity. We distinguish heterogeneity in effect size variance, heterogeneity due to a varying true underlying effect across primary studies, and heterogeneity due to a non-systematic impact of omitted variable bias in primary studies. Our results show that the mixed effects estimator is to be preferred to the other two estimators in the first two situations. However, in the presence of random effect size variation due to a non-systematic impact of omitted variable bias, using the mixed effects estimator may be suboptimal. We also address the impact of sample size and show that meta-analysis sample size is far more effective in reducing meta-estimator variance and increasing the power of hypothesis testing than primary study sample size

Enjoyable online staff development in e-assessment with feedback

This paper describes work in progress in the development of a short online course for university teaching staff to encourage and assist them in their use of e-assessment. Two important criteria for the design of the course were that it should be felt to be enjoyable and that its content should include a particular focus on giving feedback

Generalized Drinfeld-Sokolov Hierarchies II: The Hamiltonian Structures

In this paper we examine the bi-Hamiltonian structure of the generalized KdV-hierarchies. We verify that both Hamiltonian structures take the form of Kirillov brackets on the Kac-Moody algebra, and that they define a coordinated system. Classical extended conformal algebras are obtained from the second Poisson bracket. In particular, we construct the $W_n^l$ algebras, first discussed for the case $n=3$ and $l=2$ by A. Polyakov and M. Bershadsky.Comment: 41 page

The embryonic genes Dkk3, Hoxd8, Hoxd9 and Tbx1 identify muscle types in a diet-independent and fiber-type unrelated way

<p>Abstract</p> <p>Background</p> <p>The mouse skeletal muscle is composed of four distinct fiber types that differ in contractile function, number of mitochondria and metabolism. Every muscle type has a specific composition and distribution of the four fiber types. To find novel genes involved in specifying muscle types, we used microarray analysis to compare the gastrocnemius with the quadriceps from mice fed a low fat diet (LFD) or high fat diet (HFD) for 8 weeks. Additional qPCR analysis were performed in the gastrocnemius, quadriceps and soleus muscle from mice fed an LFD or HFD for 20 weeks.</p> <p>Results</p> <p>In mice fed the 8-week LFD 162 genes were differentially expressed in the gastrocnemius <it>vs</it>. the quadriceps. Genes with the strongest differences in expression were markers for oxidative fiber types (e.g. <it>Tnni1</it>) and genes which are known to be involved in embryogenesis (<it>Dkk3</it>, <it>Hoxd8</it>,<it>Hoxd9 </it>and <it>Tbx1</it>). Also <it>Dkk2, Hoxa5, Hoxa10, Hoxc9, Hoxc10, Hoxc6 </it>and <it>Tbx15 </it>were detectably, but not differentially expressed in adult muscle tissue. Expression of differentially expressed genes was not influenced by an 8-week or 20-week HFD. Comparing gastrocnemius, quadriceps and soleus, expression of <it>Hoxd8 </it>and <it>Hoxd9 </it>was not related with expression of markers for the four different fiber types. We found that the expression of both <it>Hoxd8 </it>and <it>Hoxd9 </it>was much higher in the gastrocnemius than in the quadriceps or soleus, whereas the expression of <it>Dkk3 </it>was high in quadriceps, but low in both gastrocnemius and soleus. Finally, expression of <it>Tbx1 </it>was high in quadriceps, intermediate in soleus and low in gastrocnemius.</p> <p>Conclusions</p> <p>We found that genes from the Dkk family, Hox family and Tbx family are detectably expressed in adult mouse muscle. Interestingly, expression of <it>Dkk3</it>, <it>Hoxd8, Hoxd9 </it>and <it>Tbx1 </it>was highly different between gastrocnemius, quadriceps and soleus. In fact, every muscle type showed a unique combination of expression of these four genes which was not influenced by diet. Altogether, we conclude that genes important for embryogenesis identify mouse muscle types in a diet-independent and fiber type-unrelated manner.</p

Depression Among Adults With Diabetes: Prevalence, Impact, and Treatment Options

Patients with type 1 or type 2 diabetes are two times more likely to experience depression than their peers without diabetes. Comorbid depression results in deleterious effects on glycemic control, worsened diabetes complications, functional disability, and premature mortality. Once identified, depression can be effectively treated with antidepressant medications, psychotherapy, or a combination of both. Patients and providers should monitor depressive symptoms to identify their recurrence and work collaboratively to address barriers to care that exist in both urban and rural areas

Navigating pluralism: understanding perceptions of the ecosystem services concept

Being open to multiple interpretations allows the ecosystem services concept to operate as a boundary object, facilitating communication and cooperation between different user groups. Yet there is a risk the resultant pluralism limits the capacity of ecosystem services assessments to directly inform decision and policy making, and that the concept could be used to support environmentally or socially harmful activities. Here, we report results from a large mixed methods survey conducted among academics, policymakers and practitioners working in the field of ecosystem services across Europe. We use these results to explore the trade-off that exists between the role of ecosystem services as a boundary object and the needs of policy and decision makers of more standardisation. We conclude this can be done by working towards the standardisation of ecosystem service assessments within specific jurisdictions, whilst maintaining forums for debate, collaboration, and critical reflection within the broader ecosystem services community. We also aim to deduce guiding principles to ensure the ecosystem services concept is not used to support detrimental activities. The consideration of shared and cultural values, the expansion of inter- and transdisciplinary work and the integration of the concept of sustainability are identified as valuable guiding principles to this end.</p

The preoperative cardiology consultation: Indications and risk modification

Background The cardiologist is regularly consulted preop-eratively by anaesthesiologists. However, insights into the efficiency and usefulness of these consultations are unclear. Methods This is a retrospective study of 24,174 preoperatively screened patients ≥18 years scheduled for elective non-cardiac surgery, which resulted in 273 (1%) referrals to the cardiologist for further preoperative evaluation. Medical charts were reviewed for patient characteristics, main reason for referring, requested diagnostic tests, interventions, adjustment in medical therapy, 30-day mortality and major adverse cardiac events. Results The most common reason for consultation was the evaluation of a cardiac murmur (95 patients, 35%). In 167 (61%) patients, no change in therapy was initiated by the cardiologist. Six consultations (2%) led to invasive interventions (electrical cardioversion, percutaneous coronary intervention or coronary artery bypass surgery). On average, consultation delayed clearance for surgery by two weeks. Conclusion In most patients referred to the cardiologist after being screened at an outpatient anaesthesiology clinic, echocardiography is performed for ruling out specific conditions and to be sure that no further improvement can be made in the patient’s health. In the majority, no change in therapy was initiated by the cardiologist. A more careful consideration about the potential benefits of consulting must be made for every patient