64 research outputs found
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Dislocation generation and propagation during flash lamp annealing
Dislocation generation and propagation during flash lamp annealing for 20 ms was investigated using wafers with sawed, ground, and etched surfaces. Due to the thermal stress resulting from the temperature profiles generated by the flash pre-existing dislocations propagate into the wafer from both surfaces during flash lamp annealing. A dislocation free zone was observed around 700 μm depth below the surface of a 900 μm thick sawed wafer. The dislocation propagation can be well described by a three-dimensional mechanical model. It was further demonstrated that in wafers being initially free of dislocations no dislocations are generated during flash lamp annealing
Habitat characterization and spatial distribution of Anopheles sp. mosquito larvae in Dar es Salaam (Tanzania) during an extended dry period
Introduction: By 2030, more than 50% of the African population will live in urban areas. Controlling malaria reduces the disease burden and further improves economic development. As a complement to treated nets and prompt access to treatment, measures targeted against the larval stage of Anopheles sp. mosquitoes are a promising strategy for urban areas. However, a precise knowledge of the geographic location and potentially of ecological characteristics of breeding sites is of major importance for such interventions.
Methods: In total 151 km2 of central Dar es Salaam, the biggest city of Tanzania, were systematically searched for open mosquito breeding sites. Ecologic parameters, mosquito larvae density and geographic location were recorded for each site. Logistic regression analysis was used to determine the key ecological factors explaining the different densities of mosquito larvae.
Results: A total of 405 potential open breeding sites were examined. Large drains, swamps and puddles were associated with no or low Anopheles sp. larvae density. The probability of Anopheles sp. larvae to be present was reduced when water was identified as turbid . Small breeding sites were more commonly colonized by Anopheles sp. larvae. Further, Anopheles gambiae s.l. larvae were found in highly organically polluted habitats.
Conclusions: Clear ecological characteristics of the breeding requirements of Anopheles sp. larvae could not be identified in this setting. Hence, every stagnant open water body, including very polluted ones, have to be considered as potential malaria vector breeding sites. © 2005 Sattler et al; licensee BioMed Central Ltd
Compton scattering beyond the impulse approximation
We treat the non-relativistic Compton scattering process in which an incoming
photon scatters from an N-electron many-body state to yield an outgoing photon
and a recoil electron, without invoking the commonly used frameworks of either
the impulse approximation (IA) or the independent particle model (IPM). An
expression for the associated triple differential scattering cross section is
obtained in terms of Dyson orbitals, which give the overlap amplitudes between
the N-electron initial state and the (N-1) electron singly ionized quantum
states of the target. We show how in the high energy transfer regime, one can
recover from our general formalism the standard IA based formula for the cross
section which involves the ground state electron momentum density (EMD) of the
initial state. Our formalism will permit the analysis and interpretation of
electronic transitions in correlated electron systems via inelastic x-ray
scattering (IXS) spectroscopy beyond the constraints of the IA and the IPM.Comment: 7 pages, 1 figur
Transitory Microbial Habitat in the Hyperarid Atacama Desert
Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant or dead cells. Although microbial biomass and diversity decrease with increasing aridity in the Atacama Desert, we provide multiple lines of evidence for the presence of an at times metabolically active, microbial community in one of the driest places on Earth. We base this observation on four major lines of evidence: a physico-chemical characterization of the soil habitability after an exceptional rain event, identified biomolecules indicative of potentially active cells [e.g., presence of ATP, phospholipid fatty acids (PLFAs), metabolites, and enzymatic activity], measurements of in situ replication rates of genomes of uncultivated bacteria reconstructed from selected samples, and microbial community patterns specific to soil parameters and depths. We infer that the microbial populations have undergone selection and adaptation in response to their specific soil microenvironment and in particular to the degree of aridity. Collectively, our results highlight that even the hyperarid Atacama Desert can provide a habitable environment for microorganisms that allows them to become metabolically active following an episodic increase in moisture and that once it decreases, so does the activity of the microbiota. These results have implications for the prospect of life on other planets such as Mars, which has transitioned from an earlier wetter environment to today's extreme hyperaridity. [Abstract copyright: Copyright © 2018 the Author(s). Published by PNAS.
Bragatston study protocol: a multicentre cohort study on automated quantification of cardiovascular calcifications on radiotherapy planning CT scans for cardiovascular risk prediction in patients with breast cancer
Introduction Cardiovascular disease (CVD) is an
important cause of death in breast cancer survivors.
Some breast cancer treatments including anthracyclines,
trastuzumab and radiotherapy can increase the risk of
CVD, especially for patients with pre-existing CVD risk
factors. Early identification of patients at increased CVD
risk may allow switching to less cardiotoxic treatments,
active surveillance or treatment of CVD risk factors. One of
the strongest independent CVD risk factors is the presence
and extent of coronary artery calcifications (CAC). In
clinical practice, CAC are generally quantified on ECGtriggered cardiac CT scans. Patients with breast cancer
treated with radiotherapy routinely undergo radiotherapy
planning CT scans of the chest, and those scans could
provide the opportunity to routinely assess CAC before a
potentially cardiotoxic treatment. The Bragatston study
aims to investigate the association between calcifications
in the coronary arteries, aorta and heart valves (hereinafter
called ‘cardiovascular calcifications’) measured
automatically on planning CT scans of patients with breast
cancer and CVD risk.
Methods and analysis In a first step, we will optimise
and validate a deep learning algorithm for automated
quantification of cardiovascular calcifications on
planning CT scans of patients with breast cancer.
Then, in a multicentre cohort study (University Medical
Center Utrecht, Utrecht, Erasmus MC Cancer Institute,
Rotterdam and Radboudumc, Nijmegen, The Netherlands),
the association between cardiovascular calcifications
measured on planning CT scans of patients with breast
cancer (n≈16 000) and incident (non-)fatal CVD events
will be evaluated. To assess the added predictive value of
these calcifications over traditional CVD risk factors and
treatment characteristics, a case-cohort analysis will be
performed among all cohort members diagnosed with a
CVD event during follow-up (n≈200) and a random sample
of the baseline cohort (n≈600).
Ethics and dissemination The Institutional Review
Boards of the participating hospitals decided that the
Medical R
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IDENTIFICATION OF PERIODIC STRUCTURE CHARACTERIZED FROM AMORPHOUS SUPPORT BY SIMULATION AND PROCESSING TECHNIQUES
Computer-based design techniques for the thermal analysis of low cost housing in Brazil, incorporating the use of shading by trees
SIGLEAvailable from British Library Document Supply Centre-DSC:DX192536 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Cooperative Design In A Postgraduate Distance Learning Scheme In Brazil: A Case Study On A More Sustainable Low-cost Housing Proposal
This paper describes a successful experience on distance learning in a postgraduate course in architectural and urban environment rehabilitation, as required by the urgent need to work on education in sustainability, in a larger scale and counting on contemporary non-conventional approaches. Students from five geographical regions all over Brazil, with a range of cultural and climatic characteristics, were organized into groups and asked to consider the specificities of their local realities, when presenting solutions for a low-cost more sustainable housing project. The design was to be based on eco-construction techniques, permaculture principles, sustainability strategies and humanizing concepts. The interaction between students was mainly through discussion forums and chats on the web, and the final product was formatted on a Wiki. The "South group" was one among those that reached a fairly high level of quality, when regarding at the incorporation of sustainability issues. Its work showed a thorough understanding of socioeconomic and environmental constraints, especially in terms of bioclimatic issues. Thus, it was selected to be described in more depth. This paper aims at illustrating how the group applied the design method, showing that distance learning is enabling interesting results also in the area of sustainable architecture and urban planning.95100Register, R., (2002) Ecocities, Building Cities in Balance with Nature, , Berkeley: Berkeley Hills BookAndrade, L.M.S., (2005) Agenda Verde X Agenda Marrom: Inexistência de PrincÃpios Ecológicos para o Desenho de Assentamentos Urbanos, , http://www.unb.br/fau/pesquisa/sustentabilidade/pesquisadores/Alberto/ curr%EDculo%20liza/Parte1.pdf, Dissertação (Mestrado) - Faculdade de Arquitetura e Urbanismo da Universidade de BrasÃlia. BrasÃlia [Accessed 10 January 2008]Capra, F., (2002) As Conexões Ocultas, Ciência para Um Vida Sustentável, , São Paulo: Pensamento/CultrixMollison, B., (1998) Introdução À Permacultura, , BrasÃlia: Fundação Daniel Efraim DazcalRueda, S., (1999) Modelos e Indicadores para Ciudades Más Sostenibles, , Barcelona: Departament de Medi Ambient de la Generalitat de la Catalunya/Fundació Forum AmbientalRogers, R., Gumuchdjiam, P., (2001) Cidades para Um Pequeno Planeta, , Barcelona: Editorial Gustavo GilliDauncey, G., Peck, S., 12 Features of Sustainable Community Development: Social, Economic and Environmental Benefits and Two Case Studies in Sustainable Community Development in Canada, , http://www.peck.ca/nua/, [Accessed 15 October 2009]Legan, L., (2007) A Escola Sustentável, Eco-alfabetizando Pelo Ambiente, , 2a edição atualizada e revisada - São Paulo, Imprensa Oficial do Estado de São Paulo, Pirenópolis, GO: Ecocentro IPECSattler, M.A., (2007) Habitações de Baixo Custo Mais Sustentáveis: A Casa Alvorada e o Centro Experimental de Tecnologias Habitacionais Sustentáveis, , http://www.habitare.org.br/pdf/publicacoes/arquivos/colecao9/ livro_completo.pdf, Coleção Habitare/FINEP. Porto Alegre [Accessed 10 January 2008]Barros, R.R.M.P., (2008) Habitação Coletiva: A Inclusão de Conceitos Humanizadores no Processo de Projeto, , http://libdigi.unicamp.br/document/?code=000434038, Tese (Doutorado) - Faculdade de Engenharia Civil, Arquitetura e Urbanismo, Universidade Estadual de Campinas, Campinas [Accessed 10 March 2009]Alexander, C., Ishikawa, S., Silverstein, M., Jacobson, M., Fiksdahl-King, I., Angel, S., (1977) A Pattern Language: Towns, Buildings, Construction, , New York: Oxford Uni
The geometry of the shading of buildings by trees
SIGLEAvailable from British Library Document Supply Centre- DSC:9117.28(BS--78) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
The generation of climatic building design data from meteorological data, with particular reference to Porto Alegre (30deg.02'S; 51deg.13'W), Brazil
SIGLEAvailable from British Library Document Supply Centre- DSC:9117.28(BS--80) / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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