Student midwives perspectives on the efficacy of feedback after objective structured clinical examination

Students’ experience of feedback is considered an indicator of the efficacy of the assessment process. Negative experiences of feedback are unproductive in terms of the likelihood that students will act upon and learn from assessment. To understand the impact of feedback on learning this study explored the experiences of student midwives after receiving feedback following Objective Structured Clinical Examination (OSCE). Data were collected from second year undergraduate student midwives who had recently completed OSCE, via a focus group. Students reported raised stress levels, concerns around legitimacy of feedback, and inconsistencies in the manner in which feedback was articulated. Assessment feedback in higher education should be used to empower students to become self-regulated learners. This is important for student midwives for whom a considerable amount of leaning is spent in practice. The study has implications for midwifery academics concerned with modes of assessment and quality of assessment feedback in midwifery education

Speciation by host switch in brood parasitic indigobirds

A growing body of empirical and theoretical work supports the plausibility of sympatric speciation(1-3), but there remain few examples in which all the essential components of the process are well understood. The African indigobirds Vidua spp. are host-specific brood parasites. Indigobird nestlings are reared along with host young, and mimic the mouth markings of their respective hosts(4-6). As adults, male indigobirds mimic host song(4-7), whereas females use these songs to choose both their mates and the nests they parasitize(8). These behavioural mechanisms promote the cohesion of indigobird populations associated with a given host species, and provide a mechanism for reproductive isolation after a new host is colonized. Here we show that all indigobird species are similar genetically, but are significantly differentiated in both mitochondrial haplotype and nuclear allele frequencies. These data support a model of recent sympatric speciation. In contrast to the cuckoo Cuculus canorus, in which only female lineages are faithful to specific hosts(9,10), host switches have led to speciation in indigobirds because both males and females imprint on their hosts(8,11).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62510/1/nature01863.pd

Geographical gradient of the <em>eIF4E</em> alleles conferring resistance to potyviruses in pea (<em>Pisum</em>) germplasm

<div><p>Background</p><p>The eukaryotic translation initiation factor 4E was shown to be involved in resistance against several potyviruses in plants, including pea. We combined our knowledge of pea germplasm diversity with that of the <i>eIF4E</i> gene to identify novel genetic diversity.</p><p>Methodology/Principal findings</p><p>Germplasm of 2803 pea accessions was screened for <i>eIF4E</i> intron 3 length polymorphism, resulting in the detection of four <i>eIF4E^A-B-C-S</i> variants, whose distribution was geographically structured. The <i>eIF4E^A</i> variant conferring resistance to the P1 PSbMV pathotype was found in 53 accessions (1.9%), of which 15 were landraces from India, Afghanistan, Nepal, and 7 were from Ethiopia. A newly discovered variant, <i>eIF4E^B</i>, was present in 328 accessions (11.7%) from Ethiopia (29%), Afghanistan (23%), India (20%), Israel (25%) and China (39%). The <i>eIF4E^C</i> variant was detected in 91 accessions (3.2% of total) from India (20%), Afghanistan (33%), the Iberian Peninsula (22%) and the Balkans (9.3%). The <i>eIF4E^S</i> variant for susceptibility predominated as the wild type. Sequencing of 73 samples, identified 34 alleles at the whole gene, 26 at cDNA and 19 protein variants, respectively. Fifteen alleles were virologically tested and 9 alleles (<i>eIF4E^{A-1-2-3-4-5-6-7}</i>, <i>eIF4E^B-1</i>, <i>eIF4E^C-2</i>) conferred resistance to the P1 PSbMV pathotype.</p><p>Conclusions/Significance</p><p>This work identified novel <i>eIF4E</i> alleles within geographically structured pea germplasm and indicated their independent evolution from the susceptible <i>eIF4E^S1</i> allele. Despite high variation present in wild <i>Pisum</i> accessions, none of them possessed resistance alleles, supporting a hypothesis of distinct mode of evolution of resistance in wild as opposed to crop species. The Highlands of Central Asia, the northern regions of the Indian subcontinent, Eastern Africa and China were identified as important centers of pea diversity that correspond with the diversity of the pathogen. The series of alleles identified in this study provides the basis to study the co-evolution of potyviruses and the pea host.</p></div

Glycerol Hypersensitivity in a Drosophila Model for Glycerol Kinase Deficiency Is Affected by Mutations in Eye Pigmentation Genes

Glycerol kinase plays a critical role in metabolism by converting glycerol to glycerol 3-phosphate in an ATP dependent reaction. In humans, glycerol kinase deficiency results in a wide range of phenotypic variability; patients can have severe metabolic and CNS abnormalities, while others possess hyperglycerolemia and glyceroluria with no other apparent phenotype. In an effort to help understand the pathogenic mechanisms underlying the phenotypic variation, we have created a Drosophila model for glycerol kinase deficiency by RNAi targeting of dGyk (CG18374) and dGK (CG7995). As expected, RNAi flies have reduced glycerol kinase RNA expression, reduced phosphorylation activity and elevated glycerol levels. Further investigation revealed these flies to be hypersensitive to fly food supplemented with glycerol. Due to the hygroscopic nature of glycerol, we predict glycerol hypersensitivity is a result of greater susceptibility to desiccation, suggesting glycerol kinase to play an important role in desiccation resistance in insects. To evaluate a role for genetic modifier loci in determining severity of the glycerol hypersensitivity observed in knockdown flies, we performed a preliminary screen of lethal transposon insertion mutant flies using a glycerol hypersensitive survivorship assay. We demonstrate that this type of screen can identify both enhancer and suppressor genetic loci of glycerol hypersensitivity. Furthermore, we found that the glycerol hypersensitivity phenotype can be enhanced or suppressed by null mutations in eye pigmentation genes. Taken together, our data suggest proteins encoded by eye pigmentation genes play an important role in desiccation resistance and that eye pigmentation genes are strong modifiers of the glycerol hypersensitive phenotype identified in our Drosophila model for glycerol kinase deficiency

Evolutionary Dead End in the Galápagos: Divergence of Sexual Signals in the Rarest of Darwin's Finches

Understanding the mechanisms underlying speciation remains a challenge in evolutionary biology. The adaptive radiation of Darwin's finches is a prime example of species formation, and their study has revealed many important insights into evolutionary processes. Here, we report striking differences in mating signals (songs), morphology and genetics between the two remnant populations of Darwin's mangrove finch Camarhynchus heliobates, one of the rarest species in the world. We also show that territorial males exhibited strong discrimination of sexual signals by locality: in response to foreign songs, males responded weaker than to songs from their own population. Female responses were infrequent and weak but gave approximately similar results. Our findings not only suggest speciation in the mangrove finch, thereby providing strong support for the central role of sexual signals during speciation, but they have also implications for the conservation of this iconic bird. If speciation is complete, the eastern species will face imminent extinction, because it has a population size of only 5–10 individuals

"Then you get a teacher" - Guidelines for excellence in teaching

Background: Current literature calls for the explicit teaching to health-science educators of the skills, knowledge and dispositions that are required for successful teaching in higher education. Aims: This paper draws on evidence from an Oral Hygiene department at a South African university in order to illustrate these teaching-competency needs. Insights from the evidence are synthesised with current literature regarding best teaching practice, in support of an appropriate framework for the development of teaching competencies to health-science educators. Description: A qualitative approach, using a case study, was adopted. The cohort comprised fifteen students in the first-year Oral Hygiene cohort class and the ten educators who taught their programme. Data was collected through semistructured interviews and open-ended questionnaires. The topics that emerged from the combined analysis of the interviews and the questionnaires were organised into a grid so that common themes could be identified. Current literature regarding teaching and learning was used as a framework for interpreting the empirical evidence, from which three categories emerged. The first category included suggestions from students regarding what to do to teach better. A review of the literature indicates that these competencies can be effectively learnt from self-help guides. The second category included requests for skills development. Literature review suggests that these might effectively be learnt from single-event workshops facilitated by more able peers. Responses in the final category highlighted the need for an underpinning theory of teaching and learning, and signalled the need for a more theoretically grounded and detailed approach to teacher development. Conclusion: The framework developed from the empirical study and current literature makes it possible for individual clinical teachers, and staff developers, to construct teaching-competency development plans that are pertinent to individual teachers’ needs, relevant and practical, educationally sound, and cost-effective in terms of time and effort