Improving the efficiency of thermoelectric generators by using solar heat concentrators

In this paper, we propose a method of improving the efficiency of thermoelectric generators (TEGs) by using a lens to concentrate heat on the heat source of a TEG. Initial experiments performed using discrete components show about 60mV increase in the amount of voltage generated when using a magnifying lens. Simulation results on the proposed TEG configuration exhibit up to 16% efficiency when the input heat flux is increased to 500 times that of the sun’s heat flux. The effects of varying the thermoelement length, width, and membrane diameter on the TEG’s performance are also characterized. Lastly, plans to fabricate the device on a SOI wafer in the future are presente

Design and modelling of SOI-based solar thermoelectric generators

In this work, solar micro-thermoelectric generators are designed with a lens concentrating solar radiation onto the membrane of a thermoelectric generator (TEG). By focusing solar radiation, the input heat flux increases; leading to an increase in the temperature gradient across the device. Consequently, a significant improvement in the device efficiency can be achieved. The TEG design involves the use of the SOI wafer's device layer as the first thermoelement and aluminum as the second thermoelement. Isolation trenches are also added to the design for electrical insulation. Heat transfer simulations in COMSOL are performed to verify the viability of the proposed system and an analytical model based on energy balance and heat transfer equations is developed to investigate the performance of solar TEGs with varying geometries, lens parameters, and external conditions. It is found that efficiency is improved by increasing both the concentration factor and the absorptance of the TEG membran

Regulation of Apoptosis in Hematopoietic Progenitor Cells: Involvement of Different Signaling Pathways

Proliferation, differentiation, and survival of hematopoietic stem cells and multipotent progenitor cells are regulated by cytokines and cell-cell interactions. Kit ligand (KL) and Flt3 ligand (FL) have pleiotropic effects, promotes survival, but are nonredundant. Using myeloid progenitor cell lines and mouse bone marrow-derived Lin- progenitors, we demonstrate that inhibition of phophatidylinositol (PI) 3-kinase abolish survival mediated by KL, whereas survival via FL is only partially affected. KL and FL both activate Akt, leading to inhibitory phosphorylation of the transcription factor FoxO3. Overexpression of constitutively active FoxO3, FoxO3(A3):ER, induced apoptosis even in the presence of KL or FL, indicating that inactivation of FoxO3 is crucial for signaling via both c-Kit and Flt3. Induction of FoxO3(A3):ER also inhibited myeloid and erythroid colony formation of Lin- progenitors. In addition FL, but not KL, induced expression of Bcl-2 and Bcl-xL. By overexpressing Akt and Bcl-2 we demonstrate that Bcl-2 is the better mediator of survival than Akt. However, Akt was crucial for KL-mediated survival since overexpression of dominant negative Akt induced apoptosis. We also conclude that Akt and Bcl-2 have synergistic effects since their coexpression was a far better mediator of survival than either one acting alone. In AML, Flt3 is commonly mutated via internal tandem duplications, rendering it constitutively active. Introducing Flt3-ITD into an IL-3 dependent progenitor cell line rendered it factor-independent. Both Akt and FoxO3 were phosphorylated in the absence of FL and several Bcl-2 family members were upregulated. In fact, Flt3-ITD activated additional Bcl-2 family members not activated by normal Flt3. Finally we found that PI3-kinase and an unidentified Src kinase were important for survival via Flt3-ITD. Signaling via normal Flt3 and Flt3-ITD differs in some aspects and disruption of specific Flt3-ITD signals may be potential targets for treatment

Ergonomic problems originating in the use of high-frequency and ultrasonic medical devices

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.High-frequency and ultrasonic medical devices are widely used in laparoscopic surgical procedures. Using these devices can result in ergonomic problems. Two studies were performed: in a questionnaire surgeons were asked to evaluate laparoscopic surgical instruments. Based on the resulting 74 data sets it was possible to define various improvements to the design of instruments. In a subsequent field study 70 surgical procedures were observed to comprise user caused problems in the interaction with medical devices

What works for rural development in fragile states? Evidence from Afghanistan, the Democratic Republic of the Congo, Yemen, Nepal and Bolivia.

Rural development in many fragile and conflict affected countries represents both a major challenge and an absolute must. The empirical evidence from five countries in South Asia, the Arabian Peninsula, Sub-Saharan Africa and South America (Afghanistan, Nepal, Yemen, the Democratic Republic of the Congo, and Bolivia) presented in Study I shows the major challenges rural development encounters in fragile settings

Leibniz Data Manager – An adaptive Research Data Management System

The increasing demand of researchers to make the underlying research data openly accessible, in addition to the classic publication forms, can improve the reproducibility of scientific findings, whether voluntarily or due to the institution’s or research funders’ requirements. As a result, researchers depend on expressive descriptions of research data for reusability. These descriptions are in the form of comprehensive metadata stored in heterogeneous formats in research data repositories. However, finding the appropriate data is arduous, as there is a growing amount of research data stored in various places and only a few repositories offer the function of displaying a preview of the data. Research work efficiency can benefit from data previews whenever researchers can explore portions of a dataset before deciding on the relevance of the data for accessing and downloading the whole dataset. The Leibniz Data Manager (LDM) is a research data management system that resorts to Semantic Web technologies to empower FAIR principles. LDM supports searching and exploring research data across various repositories. LDM provides an additional (meta-)data management layer for data collected from existing research data repositories based on the webbased data catalog software CKAN (Comprehensive Knowledge Archive Network). The primary purpose of LDM is to preview research data, e.g., tables, audio-visual material like AutoCAD files or 2D and 3D data, or live programming code via Jupyter Notebook(s) so that their potential for reuse can be easily evaluated. Since LDM is available as a Docker container, anyone can install a local LDM distribution to assist research data management in different phases of the data lifecycle. LDM is accessible at https://service.tib.eu/ldmservice/. LDM empowers researchers by supporting them in preserving their research data as open and FAIR as possible. With LDM, researchers can check whether their data is displayed correctly and whether it is available in suitable and preferably open data formats before publication. In addition, humans and computational programs can access machine-readable metadata, which can be exported in various schemas (DCAT, DataCite, and DublinCore) and RDF serializations. This enables automated searching and processing by various data bases and tools. More importantly, DataCite DOIs and ORCIDs ensure the persistence and findability of LDM (meta-)data. At the poster session we will demonstrate how scientists can be supported in searching for datasets and preserving their research data. We are also interested in collecting ideas about future requirements to be implemented in upcoming versions of the LDM

School principals' understanding and experiences of leadership.

Master of Education in Education Leadership, Management and Policy.The purpose of this study was to explore principals’ understanding and experiences of school leadership. The task of principals is to create learning spaces for everyone in the school and to develop them into productive leaders. It is, therefore, important to find out how principals perceive leadership and how they, through their experiences of leadership, create learning environments conducive for teaching and learning. Hence, this study adopted the transformational leadership concepts to explore the leadership experiences of the principals. A qualitative case study within the interpretive paradigm was adopted to explore the understanding and experiences of leadership of three principals. Qualitative research seeks to explain and understand social phenomena within its natural setting. It focuses on the meaning people have constructed about their world and the researcher is the primary instrument for data generation and analysis. The study attempted to make sense of the respondents life-worlds by interacting with them, appreciating and clarifying the meanings they ascribed to their experiences. Data was generated by means of semi-structured interviews and reflective journal writing and was analysed throughout the research process. The findings show that there was a general consensus amongst the principals in their understanding of leadership. What emerged from this research is that the principals realised that through their leadership, they have to play a leading role in transforming their schools into institutions of professional places of teaching and learning. For them leadership was characterised by concepts such as collective endeavours, collaborative decision making and a high degree of personal and professional standards. Their understanding and experiences of leadership also show the need for principals to build positive and trusting relationships with their staff and other stakeholders; have a caring attitude and showing understanding for the needs of others. The participants concurred that the route to lead schools better, to ensure that they become professional places of teaching and learning is rooted in fostering trusting relationships amongst themselves, the staff, parents and the community. However, their experiences of these concepts varied in accordance with their respective circumstances. In conclusion, principals must constantly communicate a clear set of values and develop a shared vision for their school. Principals must promote and care about learners and teachers’ learning. They must create opportunities for collaborative learning among staff and continual professional development. By doing so, these approaches by progressive principals create spaces for their schools to become professional places of teaching and learning, ready to cope with a changing and complex environment

Nível de conhecimento dos médicos sobre o manejo da anafilaxia em serviços de urgência e emergência de Curitiba-PR

Orientadora: Profª. Drª. Herberto José Chong NetoCoorientador: Prof. Dr. Nelson Augusto Rosário FilhoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Saúde Coletiva. Defesa: Curitiba,02/06/2017Inclui referências : f. 106-114Resumo: Anafilaxia é uma reação de hipersensibilidade generalizada ou sistêmica, reconhecida como uma das mais dramáticas condições emergenciais já identificadas. Tendo em vista que a abordagem apropriada pode representar a diferença entre a vida e a morte, o presente estudo teve como objetivos: 1) verificar o nível de conhecimento dos médicos sobre o manejo da anafilaxia nos serviços que atendem a urgências e emergências em Curitiba-PR, sendo estes: hospitais públicos ou privados e Unidades de Pronto Atendimento / Serviço de Atendimento Móvel de Urgência (UPA/SAMU), e 2) levantar informações acerca de treinamento periódico em serviço sobre este quadro clínico nas instituições participantes. Foram pesquisados cento e cinquenta e sete médicos que atuavam em oito hospitais e nove Unidades de Pronto Atendimento do município, por meio de questionário autoaplicável. Os resultados obtidos permitiram considerar o nível de conhecimento dos médicos de Curitiba superior ao encontrado em outras duas cidades brasileiras que utilizaram a mesma metodologia, no entanto, com importantes deficiências quando comparado a estudos internacionais que também adotaram métodos semelhantes. Os médicos que atuavam no segmento hospitalar demonstraram melhor conhecimento do que os que atuavam em UPA/SAMU na maioria dos aspectos pesquisados. Os participantes com tempo de formação de um a dez anos também obtiveram melhor desempenho quando comparados aos formados há mais de dez anos. No entanto, nenhum dos segmentos ou grupos obteve resultados considerados satisfatórios. As principais deficiências encontradas foram: conhecimento insuficiente quanto à adrenalina intramuscular e à possibilidade de reaplicação desta, desconhecimento sobre a utilização do glucagon e do posicionamento do paciente com membros inferiores elevados. O tempo de observação considerado pelos médicos após a resolução do quadro anafilático representou o único resultado visivelmente favorável encontrado nesta amostra. Verificou-se, ainda, que não existe treinamento periódico sobre a anafilaxia nos serviços pesquisados. Pretende-se, a partir disto, alertar os profissionais e gestores quanto à necessidade de conhecimento acerca deste quadro clínico potencialmente fatal, principalmente quando não tratado adequadamente. Descritores: anafilaxia, conhecimento, serviços médicos de emergência, epinefrina.Abstract: Anaphylaxis is a generalized or systemic hypersensitivity reaction, recognized as one of the most dramatic emergency conditions ever identified. Considering that the appropriate approach may represent the difference between life and death, the present study aimed to: 1) verify the level of knowledge of physicians on the management of anaphylaxis in emergency services in Curitiba-PR, being: public or private hospitals and Emergency Care Units / Mobile Emergency Attendance Service, and 2) collect information about in-service periodic training on this clinical picture in the institutions surveyed. METHODS: One hundred fifty-seven physicians who worked in eight hospitals and nine Emergency Care Units in the city were surveyed using a self-administered questionnaire. The results obtained allowed to consider the level of knowledge of physicians from Curitiba better than that found in other two Brazilian cities that used the same methodology, however, with important deficits when compared to international studies which also adopted similar methods. The physicians who worked in the hospital group demonstrated better knowledge than those who worked in Emergency Care Units / Mobile Emergency Attendance Service in most of the aspects surveyed. Participants with training time from one to ten years also performed better when compared to those trained more than ten years ago. However, it should be clarified that none of the groups obtained satisfactory results. The main deficits were: insufficient knowledge about adrenaline intramuscular and the possibility of reapplication of this, lack of knowledge about the use of glucagon and the positioning of the patient with lower extremities elevated. The observance period considered by the physicians after a resolution of the anaphylactic case represents the only outcome visibly favorable found in this sample. It was also verified that there is no periodic training on anaphylaxis in the services surveyed. It is intended, therefore, to alert professionals as well as managers to the need of awareness about this potentially fatal clinical situation, especially when not treated properly. Keywords: anaphylaxis, knowledge, emergency medical services, epinephrine

A novel FRET-based screen in high-throughput format to identify inhibitors of malarial and human glucose transporters

The glucose transporter PfHT is essential to the survival of the malaria parasite Plasmodium falciparum and has been shown to be a druggable target with high potential for pharmacological intervention. Identification of compounds against novel drug targets is crucial to combating resistance against current therapeutics. Here, we describe the development of a cell-based assay system readily adaptable to high-throughput screening that directly measures compound effects on PfHT-mediated glucose transport. Intracellular glucose concentrations are detected using a genetically encoded fluorescence resonance energy transfer (FRET)-based glucose sensor. This allows assessment of the ability of small molecules to inhibit glucose uptake with high accuracy (Z′ factor of >0.8), thereby eliminating the need for radiolabeled substrates. Furthermore, we have adapted this assay to counterscreen PfHT hits against the human orthologues GLUT1, -2, -3, and -4. We report the identification of several hits after screening the Medicines for Malaria Venture (MMV) Malaria Box, a library of 400 compounds known to inhibit erythrocytic development of P. falciparum. Hit compounds were characterized by determining the half-maximal inhibitory concentration (IC(50)) for the uptake of radiolabeled glucose into isolated P. falciparum parasites. One of our hits, compound MMV009085, shows high potency and orthologue selectivity, thereby successfully validating our assay for antimalarial screening