Towards a knowledge-rich learning environment in preparatory secondary education

In this case study a novel educational programme for students in preparatory vocational education was studied. The research questions were: (1) Which teaching/learning processes occur in a simulated workplace using the concept of a knowledge-rich workplace? (2) What is the role of models and modelling in the teaching/learning processes? The curriculum project consisted of design and construction tasks. The students were collaboratively involved in the process of designing a tricycle for a real customer. This real-life activity creates opportunities for students to develop and use models, which can be used in more than in one context. The case study explored how the teachers deal with the students' explicit and implicit need for knowledge and skills. The main findings are that teachers more often provide this knowledge, rather than guide the students in reconstructing it, and towards the end of the project, knowledge tended to remain situated

The use of mesenchymal stem cells for cartilage repair and regeneration: a systematic review.

BACKGROUND: The management of articular cartilage defects presents many clinical challenges due to its avascular, aneural and alymphatic nature. Bone marrow stimulation techniques, such as microfracture, are the most frequently used method in clinical practice however the resulting mixed fibrocartilage tissue which is inferior to native hyaline cartilage. Other methods have shown promise but are far from perfect. There is an unmet need and growing interest in regenerative medicine and tissue engineering to improve the outcome for patients requiring cartilage repair. Many published reviews on cartilage repair only list human clinical trials, underestimating the wealth of basic sciences and animal studies that are precursors to future research. We therefore set out to perform a systematic review of the literature to assess the translation of stem cell therapy to explore what research had been carried out at each of the stages of translation from bench-top (in vitro), animal (pre-clinical) and human studies (clinical) and assemble an evidence-based cascade for the responsible introduction of stem cell therapy for cartilage defects. This review was conducted in accordance to PRISMA guidelines using CINHAL, MEDLINE, EMBASE, Scopus and Web of Knowledge databases from 1st January 1900 to 30th June 2015. In total, there were 2880 studies identified of which 252 studies were included for analysis (100 articles for in vitro studies, 111 studies for animal studies; and 31 studies for human studies). There was a huge variance in cell source in pre-clinical studies both of terms of animal used, location of harvest (fat, marrow, blood or synovium) and allogeneicity. The use of scaffolds, growth factors, number of cell passages and number of cells used was hugely heterogeneous. SHORT CONCLUSIONS: This review offers a comprehensive assessment of the evidence behind the translation of basic science to the clinical practice of cartilage repair. It has revealed a lack of connectivity between the in vitro, pre-clinical and human data and a patchwork quilt of synergistic evidence. Drivers for progress in this space are largely driven by patient demand, surgeon inquisition and a regulatory framework that is learning at the same pace as new developments take place

Respostas hormonais ao tratamento com GnRH e estradiol e suas correlações com desenvolvimento testicular e número de células sertoli em touros angus x charolês na fase de pré-puberdade

O objetivo desta pesquisa foi determinar as correlações entre níveis hormonais aos 2 e 6 meses de idade e diâmetro e histologia testicular em tourinhos Angus x Charolês aos 6 meses de idade (n=15). Aos dois meses, duas amostras basais de sangue foram coletadas a intervalos de 1 hora. Após a última coleta, os animais receberam 5 mg de GnRH e 1,5 e 3,0 horas depois novas amostras foram coletadas. Aos seis meses, os tourinhos foram tratados com 1 mg de estradiol benzoato (E) e receberam 10 mg de GnRH doze horas depois. Após cinco dias, os tourinhos receberam 10 mg de GnRH, mas sem pré-tratamento com estradiol. As amostras de sangue foram coletadas 1,5 e 3,0 horas após a injeção de GnRH nas duas ocasiões. Imediatamente antes dos tratamentos com estradiol e GnRH, duas amostras basais foram coletadas. Os animais foram cirurgicamente castrados aos seis meses. Houve correlações entre níveis de FSH estimulados com GnRH aos dois meses e diâmetro testicular e número de células Sertoli e espermatogônias A1 por testículo aos seis meses de idade (r = -0,65 a -0,80). As associações entre FSH aos dois meses e número de seções de túbulos seminíferos sem células germinativas (r = 0,59) e número de túbulos com espermátides circulares (r = -0,55) também foram significativas. As correlações entre níveis de LH e esteróides e parâmetros testiculares não foram significativas. Aos 6 meses, níveis basais de FSH não alteraram 12 horas após estradiol, mas as concentrações de FSH estimuladas com GnRH foram 2,5 vezes mais elevadas, quando se usou estradiol em relação ao uso somente de GnRH. Modelos de regressão com número de células Sertoli, em função dos níveis de FSH após GnRH, mostraram que, quando se utilizaram GnRH + estradiol, obteve-se maior valor de R² (0,43) em comparação à injeção somente de GnRH (0,30). Portanto, concentrações periféricas de FSH são potenciais indicadores do desenvolvimento testicular na fase de pré-puberdade