Problem-based learning in dental education: what's the evidence for and against... and is it worth the effort?

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.All Australian dental schools have introduced problem-based learning (PBL) approaches to their programmes over the past decade, although the nature of the innovations has varied from school to school. Before one can ask whether PBL is better than the conventional style of education, one needs to consider three key issues. Firstly, we need to agree on what is meant by the term PBL; secondly, we need to decide what “better” means when comparing educational approaches; and thirdly, we must look carefully at how PBL is implemented in given situations. It is argued that PBL fulfils, at least in theory, some important principles relating to the development of new knowledge. It also represents a change in focus from teachers and teaching in conventional programmes to learners and learning. Generally, students enjoy PBL programmes more than conventional programmes and feel they are more nurturing. There is also some evidence of an improvement in clinical and diagnostic reasoning ability associated with PBL curricula. The main negative points raised about PBL are the costs involved and mixed reports of insufficient grounding of students in the basic sciences. Financial restraints will probably preclude the introduction of pure or fully integrated PBL programmes in Australian dental schools. However, our research and experience, as well as other published literature, indicate that well-planned hybrid PBL programmes, with matching methods of assessment, can foster development of the types of knowledge, skills and attributes that oral health professionals will need in the future.T Winning and G Townsen

Characterization of the 1st and 2nd EF-hands of NADPH oxidase 5 by fluorescence, isothermal titration calorimetry, and circular dichroism

<p>Abstract</p> <p>Background</p> <p>Superoxide generated by non-phagocytic NADPH oxidases (NOXs) is of growing importance for physiology and pathobiology. The calcium binding domain (CaBD) of NOX5 contains four EF-hands, each binding one calcium ion. To better understand the metal binding properties of the 1^stand 2^ndEF-hands, we characterized the N-terminal half of CaBD (NCaBD) and its calcium-binding knockout mutants.</p> <p>Results</p> <p>The isothermal titration calorimetry measurement for NCaBD reveals that the calcium binding of two EF-hands are loosely associated with each other and can be treated as independent binding events. However, the Ca²⁺binding studies on NCaBD(E31Q) and NCaBD(E63Q) showed their binding constants to be 6.5 × 10⁵and 5.0 × 10²M^-1with ΔHs of -14 and -4 kJ/mol, respectively, suggesting that intrinsic calcium binding for the 1^stnon-canonical EF-hand is largely enhanced by the binding of Ca²⁺to the 2^ndcanonical EF-hand. The fluorescence quenching and CD spectra support a conformational change upon Ca²⁺binding, which changes Trp residues toward a more non-polar and exposed environment and also increases its α-helix secondary structure content. All measurements exclude Mg²⁺-binding in NCaBD.</p> <p>Conclusions</p> <p>We demonstrated that the 1^stnon-canonical EF-hand of NOX5 has very weak Ca²⁺binding affinity compared with the 2^ndcanonical EF-hand. Both EF-hands interact with each other in a cooperative manner to enhance their Ca²⁺binding affinity. Our characterization reveals that the two EF-hands in the N-terminal NOX5 are Ca²⁺specific.</p> <p>Graphical abstract</p> <p><display-formula><graphic file="1752-153X-6-29-i1.gif"/></display-formula></p

A randomized, controlled clinical trial: the effect of mindfulness-based cognitive therapy on generalized anxiety disorder among Chinese community patients: protocol for a randomized trial

&lt;b&gt;Background&lt;/b&gt; Research suggests that an eight-week Mindfulness-Based Cognitive Therapy (MBCT) program may be effective in the treatment of generalized anxiety disorders. Our objective is to compare the clinical effectiveness of the MBCT program with a psycho-education programme and usual care in reducing anxiety symptoms in people suffering from generalized anxiety disorder.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods and Design&lt;/b&gt; A three armed randomized, controlled clinical trial including 9-month post-treatment follow-up is proposed. Participants screened positive using the Structure Clinical Interview for DSM-IV (SCID) for general anxiety disorder will be recruited from community-based clinics. 228 participants will be randomly allocated to the MBCT program plus usual care, psycho-education program plus usual care or the usual care group. Validated Chinese version of instruments measuring anxiety and worry symptoms, depression, quality of life and health service utilization will be used. Our primary end point is the change of anxiety and worry score (Beck Anxiety Inventory and Penn State Worry Scale) from baseline to the end of intervention. For primary analyses, treatment outcomes will be assessed by ANCOVA, with change in anxiety score as the baseline variable, while the baseline anxiety score and other baseline characteristics that significantly differ between groups will serve as covariates.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Discussion&lt;/b&gt; This is a first randomized controlled trial that compare the effectiveness of MBCT with an active control, findings will advance current knowledge in the management of GAD and the way that group intervention can be delivered and inform future research

The Princeton Protein Orthology Database (P-POD): A Comparative Genomics Analysis Tool for Biologists

Many biological databases that provide comparative genomics information and tools are now available on the internet. While certainly quite useful, to our knowledge none of the existing databases combine results from multiple comparative genomics methods with manually curated information from the literature. Here we describe the Princeton Protein Orthology Database (P-POD, http://ortholog.princeton.edu), a user-friendly database system that allows users to find and visualize the phylogenetic relationships among predicted orthologs (based on the OrthoMCL method) to a query gene from any of eight eukaryotic organisms, and to see the orthologs in a wider evolutionary context (based on the Jaccard clustering method). In addition to the phylogenetic information, the database contains experimental results manually collected from the literature that can be compared to the computational analyses, as well as links to relevant human disease and gene information via the OMIM, model organism, and sequence databases. Our aim is for the P-POD resource to be extremely useful to typical experimental biologists wanting to learn more about the evolutionary context of their favorite genes. P-POD is based on the commonly used Generic Model Organism Database (GMOD) schema and can be downloaded in its entirety for installation on one's own system. Thus, bioinformaticians and software developers may also find P-POD useful because they can use the P-POD database infrastructure when developing their own comparative genomics resources and database tools

Measurement of Trilinear Gauge Couplings in e+e−e^+ e^- Collisions at 161 GeV and 172 GeV

Trilinear gauge boson couplings are measured using data taken by DELPHI at 161~GeV and 172~GeV. Values for $WWV$ couplings ($V=Z, \gamma$) are determined from a study of the reactions \eeWW\ and \eeWev, using differential distributions from the $WW$ final state in which one $W$ decays hadronically and the other leptonically, and total cross-section data from other channels. Limits are also derived on neutral $ZV\gamma$ couplings from an analysis of the reaction \eegi

Search for neutral heavy leptons produced in ZZ decays

Weak isosinglet Neutral Heavy Leptons (νm) have been searched for using data collected by the DELPHI detector corresponding to 3.3 × 106 hadronic Z0 decays at LEP1. Four separate searches have been performed, for short-lived νm production giving monojet or acollinear jet topologies, and for long-lived νm giving detectable secondary vertices or calorimeter clusters. No indication of the existence of these particles has been found, leading to an upper limit for the branching ratio BR(Z0 → νmν̄) of about 1.3 × 10-6 at 95% confidence level for νm masses between 3.5 and 50 GeV/c2. Outside this range the limit weakens rapidly with the νm mass. The results are also interpreted in terms of limits for the single production of excited neutrinos. © Springer-Verlag 1997

Causes, consequences and biomarkers of stress in swine: an update

BACKGROUND: In recent decades there has been a growing concern about animal stress on intensive pig farms due to the undesirable consequences that stress produces in the normal physiology of pigs and its effects on their welfare and general productive performance. This review analyses the most important types of stress (social, environmental, metabolic, immunological and due to human handling), and their biological consequences for pigs. The physio-pathological changes associated with stress are described, as well as the negative effects of stress on pig production. In addition an update of the different biomarkers used for the evaluation of stress is provided. These biomarkers can be classified into four groups according to the physiological system or axis evaluated: sympathetic nervous system, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-gonadal axis and immune system. CONCLUSIONS: Stress it is a process with multifactorial causes and produces an organic response that generates negative effects on animal health and production. Ideally, a panel of various biomarkers should be used to assess and evaluate the stress resulting from diverse causes and the different physiological systems involved in the stress response. We hope that this review will increase the understanding of the stress process, contribute to a better control and reduction of potential stressful stimuli in pigs and, finally, encourage future studies and developments to better monitor, detect and manage stress on pig farms

‘It’s different for guys’: Gendered narratives of racial conflict among white California youth

As race talk has gained attention throughout the social sciences, sociocultural linguistics has become crucial in revealing how racial ideologies and identities are discursively produced. This article examines how race talk may reproduce racial binaries while perpetuating gender ideologies. Drawing on ethnographically collected narratives of conflict at an ethnoracially divided California high school, the analysis examines three discursive practices of racial reversal whereby white youth portray themselves as disadvantaged vis-a-vis their black peers: claims of ‘reverse discrimination’, narratives of racialized fear, and fight stories. Whereas white girls’ narratives relied on racial vagueness, white boys’ narratives highlighted racial difference, contrastive strategies that indicate the different racial stakes for white girls versus white boys at the school. The article demonstrates the necessity of examining race talk not only for its content but also for its discursive structure, its ethnographic and interactional context, its co-construction by the researcher, and its ideological effects