3,248 research outputs found
How are "teaching the teachers" courses in evidence based medicine evaluated? A systematic review
Background
Teaching of evidence-based medicine (EBM) has become widespread in medical education. Teaching the teachers (TTT) courses address the increased teaching demand and the need to improve effectiveness of EBM teaching. We conducted a systematic review of assessment tools for EBM TTT courses. To summarise and appraise existing assessment methods for teaching the teachers courses in EBM by a systematic review.
Methods
We searched PubMed, BioMed, EmBase, Cochrane and Eric databases without language restrictions and included articles that assessed its participants. Study selection and data extraction were conducted independently by two reviewers.
Results
Of 1230 potentially relevant studies, five papers met the selection criteria. There were no specific assessment tools for evaluating effectiveness of EBM TTT courses. Some of the material available might be useful in initiating the development of such an assessment tool.
Conclusion
There is a need for the development of educationally sound assessment tools for teaching the teachers courses in EBM, without which it would be impossible to ascertain if such courses have the desired effect
Involvement of Noradrenergic Neurotransmission in the Stress- but not Cocaine-Induced Reinstatement of Extinguished Cocaine-Induced Conditioned Place Preference in Mice: Role for β-2 Adrenergic Receptors
The responsiveness of central noradrenergic systems to stressors and cocaine poses norepinephrine as a potential common mechanism through which drug re-exposure and stressful stimuli promote relapse. This study investigated the role of noradrenergic systems in the reinstatement of extinguished cocaine-induced conditioned place preference by cocaine and stress in male C57BL/6 mice. Cocaine- (15 mg/kg, i.p.) induced conditioned place preference was extinguished by repeated exposure to the apparatus in the absence of drug and reestablished by a cocaine challenge (15 mg/kg), exposure to a stressor (6-min forced swim (FS); 20–25°C water), or administration of the α-2 adrenergic receptor (AR) antagonists yohimbine (2 mg/kg, i.p.) or BRL44408 (5, 10 mg/kg, i.p.). To investigate the role of ARs, mice were administered the nonselective β-AR antagonist, propranolol (5, 10 mg/kg, i.p.), the α-1 AR antagonist, prazosin (1, 2 mg/kg, i.p.), or the α-2 AR agonist, clonidine (0.03, 0.3 mg/kg, i.p.) before reinstatement testing. Clonidine, prazosin, and propranolol failed to block cocaine-induced reinstatement. The low (0.03 mg/kg) but not high (0.3 mg/kg) clonidine dose fully blocked FS-induced reinstatement but not reinstatement by yohimbine. Propranolol, but not prazosin, blocked reinstatement by both yohimbine and FS, suggesting the involvement of β-ARs. The β-2 AR antagonist ICI-118551 (1 mg/kg, i.p.), but not the β-1 AR antagonist betaxolol (10 mg/kg, i.p.), also blocked FS-induced reinstatement. These findings suggest that stress-induced reinstatement requires noradrenergic signaling through β-2 ARs and that cocaine-induced reinstatement does not require AR activation, even though stimulation of central noradrenergic neurotransmission is sufficient to reinstate
Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia
Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration
The luminosity function of field galaxies
Schmidt's method for construction of luminosity function of galaxies is
generalized by taking into account the dependence of density of galaxies from
the distance in the near Universe. The logarithmical luminosity function (LLF)
of field galaxies depending on morphological type is constructed. We show that
the LLF for all galaxies, and also separately for elliptical and lenticular
galaxies can be presented by Schechter function in narrow area of absolute
magnitudes. The LLF of spiral galaxies was presented by Schechter function for
enough wide area of absolute magnitudes: . Spiral galaxies differ slightly by
parameter . At transition from early spirals to the late spirals parameter in
Schechter function is reduced. The reduction of mean luminosity of galaxies is
observed at transition from elliptical galaxies to lenticular galaxies, to
early spiral galaxies, and further, to late spiral galaxies, in a bright end, .
The completeness and the average density of samples of galaxies of different
morphological types are estimated. In the range the mean number density of all
galaxies is equal 0.127 Mpc-3.Comment: 14 page, 8 figures, to appear in Astrophysic
Induction of humoral immune response to multiple recombinant Rhipicephalus appendiculatus antigens and their effect on tick feeding success and pathogen transmission
BACKGROUND: Rhipicephalus appendiculatus is the primary vector of Theileria parva, the etiological agent of East Coast fever (ECF), a devastating disease of cattle in sub-Saharan Africa. We hypothesized that a vaccine targeting tick proteins that are involved in attachment and feeding might affect feeding success and possibly reduce tick-borne transmission of T. parva. Here we report the evaluation of a multivalent vaccine cocktail of tick antigens for their ability to reduce R. appendiculatus feeding success and possibly reduce tick-transmission of T. parva in a natural host-tick-parasite challenge model.
METHODS: Cattle were inoculated with a multivalent antigen cocktail containing recombinant tick protective antigen subolesin as well as two additional R. appendiculatus saliva antigens: the cement protein TRP64, and three different histamine binding proteins. The cocktail also contained the T. parva sporozoite antigen p67C. The effect of vaccination on the feeding success of nymphal and adult R. appendiculatus ticks was evaluated together with the effect on transmission of T. parva using a tick challenge model.
RESULTS: To our knowledge, this is the first evaluation of the anti-tick effects of these antigens in the natural host-tick-parasite combination. In spite of evidence of strong immune responses to all of the antigens in the cocktail, vaccination with this combination of tick and parasite antigens did not appear to effect tick feeding success or reduce transmission of T. parva.
CONCLUSION: The results of this study highlight the importance of early evaluation of anti-tick vaccine candidates in biologically relevant challenge systems using the natural tick-host-parasite combination
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The secretome of alginate-encapsulated limbal epithelial stem cells modulates corneal epithelial cell proliferation
Limbal epithelial stem cells may ameliorate limbal stem cell deficiency through secretion of therapeutic proteins, delivered to the cornea in a controlled manner using hydrogels. In the present study the secretome of alginate-encapsulated limbal epithelial stem cells is investigated. Conditioned medium was generated from limbal epithelial stem cells encapsulated in 1.2% (w/v) calcium alginate gels. Conditioned medium proteins separated by 1-D gel electrophoresis were visualized by silver staining. Proteins of interest including secreted protein acidic and rich in cysteine, profilin-1, and galectin-1 were identified by immunoblotting. The effect of conditioned medium (from alginate-encapsulated limbal epithelial stem cells) on corneal epithelial cell proliferation was quantified and shown to significantly inhibit (P</=0.05) their growth. As secreted protein acidic and rich in cysteine was previously reported to attenuate proliferation of epithelial cells, this protein may be responsible, at least in part, for inhibition of corneal epithelial cell proliferation. We conclude that limbal epithelial stem cells encapsulated in alginate gels may regulate corneal epithelialisation through secretion of inhibitory proteins
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Resposta terapêutica e profilática com ferro e ácido fólico na anemia em crianças de creches públicas em Goiânia, Goiás, Brasil: ensaio clínico randomizado
The objective of this study was to assess the prevalence of anemia and the therapeutic and prophylactic response to ferrous sulfate and folic acid. A double-blind, randomized, controlled clinical trial was conducted with 196 children 6 to 24 months of age enrolled in municipal daycare centers in Goiânia, Goiás State, Brazil. The children were assigned to two treatment groups that received a daily dose (5 times a week) of either 4.2mg/kg/day of ferrous sulfate + folic acid (50µg) or 4.2mg/kg/day of ferrous sulfate + folic acid placebo. One of the prevention groups received 1.4mg/kg/day of ferrous sulfate + folic acid (50µg/day) and the other 1.4mg/kg/day of ferrous sulfate + folic acid placebo. Supplementation lasted approximately three months. Baseline anemia prevalence was 56.1% (95%CI: 48.9-63.1). After treatment, anemia prevalence in the folic acid group (14%) was lower than in the placebo group (34.9%) (p = 0.02). After prophylaxis in the non-anemic children, the incidence of anemia did not differ between the groups, but there was an increase in hemoglobin level in the folic acid group (p = 0.003). Iron plus folic acid was effective for the treatment of anemia and improvement of hemoglobin level in non-anemic children.Avaliar a prevalência de anemia e a resposta terapêutica e profilática do sulfato ferroso e ácido fólico. Realizou-se um ensaio clínico controlado randomizado, duplo-cego, com 196 crianças de 6 a 24 meses, dos Centros Municipais de Educação Infantil de Goiânia, Goiás, Brasil. As crianças foram alocadas em dois grupos de tratamento que receberam dose diária (5x/semana) com 4,2mg/kg/dia de sulfato ferroso + ácido fólico (50µg) ou 4,2mg/kg/dia de sulfato ferroso + placebo de ácido fólico. Um dos grupos de prevenção recebeu 1,4 mg/kg/dia de sulfato ferroso + ácido fólico (50µg/dia) e o outro 1,4mg/kg/dia de sulfato ferroso + placebo de ácido fólico. A suplementação durou cerca de três meses. A prevalência de anemia inicial foi de 56,1% (IC95%: 48,9-63,1). Após o tratamento, a prevalência de anemia no grupo ácido fólico (14%) foi menor que no grupo placebo (34,9%; p = 0,02). Após profilaxia dos não anêmicos, a incidência de anemia não diferiu entre os grupos, porém, houve incremento da hemoglobina no grupo ácido fólico (p = 0,003). O ferro associado com ácido fólico foi eficaz no tratamento da anemia e na melhoria da hemoglobina nos não anêmicos.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de Goiás Faculdade de NutriçãoUniversidade Federal de São Paulo (UNIFESP)Universidade Federal de Goiás Instituto de Patologia Tropical e Saúde PúblicaVila São José Bento CotolengoUNIFESPSciEL
Psychological morbidity as a moderator of intention to quit smoking : a study of smokers and former smokers
Objective: To analyze psychological morbidity as a moderator of the relationship between smoking representations and quality of life in smokers and former smokers, as well as to determine which psychological variables discriminate between smokers with and without the intention to quit smoking. Methods: This was a quantitative, correlational cross-sectional study involving a convenience sample of 224 smokers and 169 former smokers. Results: In smokers and former smokers, psychological morbidity had a moderating effect on the relationship between mental/physical quality of life and smoking representations (cognitive representations, emotional representations, and comprehensibility). Smokers with the intention to quit smoking more often presented with low comprehensibility, threatening emotional representations, behavioral beliefs, and perceived behavioral control, as well as with normative/control beliefs, than did those without the intention to quit. Conclusions: The results of this study underscore the importance of the moderating effect exerted by psychological morbidity, as well as that of sociocognitive variables, among smokers who have the intention to quit smoking.ResumoObjetivo: Analisar a morbidade psicológica como um moderador na relação entre as representações do tabaco e a qualidade de vida em fumantes e ex-fumantes, assim como conhecer as variáveis psicológicas que discriminam os fumantes com e sem intenção para deixar de fumar. Métodos: Estudo quantitativo, correlacional e transversal com uma amostra de conveniência constituída por 224 fumantes e 169 ex-fumantes. Resultados: Verificou-se um efeito moderador da morbidade psicológica na relação entre a qualidade de vida (física e mental) e as representações do tabaco (representações cognitivas e emocionais e compreensão) nos fumantes e nos ex-fumantes. Os fumantes com intenção para deixar de fumar apresentavam menor compreensão, representações emocionais mais ameaçadoras, mais crenças de comportamento, maior controle comportamental percebido e mais crenças normativas/controle do que aqueles sem essa intenção. Conclusões: Os resultados deste estudo enfatizam a importância da morbidade psicológica como moderadora, bem como das variáveis sociocognitivas, junto dos fumantes que querem deixar de fumar
Performance benchmarks for a next generation numerical dynamo model
Numerical simulations of the geodynamo have successfully represented many observable characteristics of the geomagnetic field, yielding insight into the fundamental processes that generate magnetic fields in the Earth's core. Because of limited spatial resolution, however, the diffusivities in numerical dynamo models are much larger than those in the Earth's core, and consequently, questions remain about how realistic these models are. The typical strategy used to address this issue has been to continue to increase the resolution of these quasi-laminar models with increasing computational resources, thus pushing them toward more realistic parameter regimes. We assess which methods are most promising for the next generation of supercomputers, which will offer access to O(106) processor cores for large problems. Here we report performance and accuracy benchmarks from 15 dynamo codes that employ a range of numerical and parallelization methods. Computational performance is assessed on the basis of weak and strong scaling behavior up to 16,384 processor cores. Extrapolations of our weak-scaling results indicate that dynamo codes that employ two-dimensional or three-dimensional domain decompositions can perform efficiently on up to ∼106 processor cores, paving the way for more realistic simulations in the next model generation
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