1,512 research outputs found
Osteogenic Transcription Regulated by Exaggerated Stretch Loading via Convergent Wnt Signaling
Cell and animal studies conducted onboard the International Space Station and formerly the Shuttle flights have provided data illuminating the deleterious biological response of bone to mechanical unloading. Down regulation of proliferative mechanisms within stem cell populations of the osteogenic niche is a suggested mechanism for loss of bone mass. However the intercellular communicative cues from osteoblasts and osteocytes in managing stem cell proliferation and osteogenic differentiation are largely unknown. In this investigation, MLO-Y4 osteocyte-like and MC3T3-E1 osteoblast-like cells, are co-culture under dynamic tensile conditions and evaluated for phenotypic expression of biochemical signaling proteins influential in driving stem cell differentiation. MLO-Y4 and MC3T3-E1 were co-cultured on polyethersulfone membrane with a 0.45m porosity to permit soluble factor transfer and direct cell-cell gap junction signaling. Cyclic tensile stimulation was applied for 48 h at a frequency of 0.1Hz and strain of 0.1. Total Live cell counts indicate mechanical activation of MC3T3-E1s inhibits proliferation while MLO-Y4s increase in number. However, the percent of live MLO-Y4s within the population is low (46.3 total count, *p0.05, n4) suggesting a potential apoptotic signaling cascade. Immunofluorescence demonstrated that stimulation of co-cultures elicits increased gap junction communication. Previously reported PCR evaluation of osteogenic markers further corroborate that the co-cultured populations communicative networks play a role in translating mechanical signals to molecular messaging. These findings suggest that an osteocyte-osteoblast signaling feedback mechanism may regulate mechanotransduction of an apoptotic cascade within osteocytes and transcription of cytokine signaling proteins responsible for stem cell niche recruitment much more directly than previously believed
Solving security constrained optimal power flow problems:a hybrid evolutionary approach
A hybrid population-based metaheuristic, Hybrid Canonical Differential Evolutionary Particle Swarm Optimization (hC-DEEPSO), is applied to solve Security Constrained Optimal Power Flow (SCOPF) problems. Despite the inherent difficulties of tackling these real-world problems, they must be solved several times a day taking into account operation and security conditions. A combination of the C-DEEPSO metaheuristic coupled with a multipoint search operator is proposed to better exploit the search space in the vicinity of the best solution found so far by the current population in the first stages of the search process. A simple diversity mechanism is also applied to avoid premature convergence and to escape from local optima. A experimental design is devised to fine-tune the parameters of the proposed algorithm for each instance of the SCOPF problem. The effectiveness of the proposed hC-DEEPSO is tested on the IEEE 57-bus, IEEE 118-bus and IEEE 300-bus standard systems. The numerical results obtained by hC-DEEPSO are compared with other evolutionary methods reported in the literature to prove the potential and capability of the proposed hC-DEEPSO for solving the SCOPF at acceptable economical and technical levels
Gestão da água e das águas residuais para uma viticultura e enologia sustentáveis no sul de Portugal - Revisão
Assessing sustainability of the wine industry requires improved characterization of its environmental impacts, namely in terms of water use.
Therefore, quantification of water inputs and wastewater (WW) outputs is needed to highlight inefficiencies in wine production and related
consequences for the environment. Water use and WW generation in irrigated viticulture and oenology remains insufficiently quantified for dry
Mediterranean regions (e.g. South Portugal). This paper is focused on wine production under warm and dry climate conditions in the winegrowing
region of Alentejo (South Portugal). This region experiences increasingly dry conditions, while the irrigated area keeps expanding, which puts
exacerbates the pressure on existing local and regional water resources. Additionally, more erratic variation in climate conditions and the tendency
for increasingly extreme climate events (e.g. heat waves) pose more challenges to Alentejo’s wine sector. We conclude that quantitative
information on water use and management is not always easy to obtain or access, which hinders improved strategies and/or policies for water use
at farm, winery and region-level. Up-to-date statistics and robust metrics can help to better characterize water use and WW flows for Alentejo’s
wine region, while optimizing management in vineyards and wineries, in companies and region-wide. The paper is focused on a “Farm-Winery"
scenario, which is the most common in South Portugal's wine sectorA avaliação da sustentabilidade da indústria vitivinícola requer uma caracterização detalhada do seu impacto ambiental, nomeadamente ao nível
do factor água. A quantificação detalhada dos consumos de água e das águas residuais produzidas (WW) é crucial para identificação de
ineficiências na indústria da vinha e do vinho. A utilização da água e a gestão dos efluentes em viticultura regada e na adega permanecem pouco
quantificados nas regiões mediterrânicas. O presente trabalho centra-se na produção de vinho em condições de clima quente e seco, tomando
como exemplo a região vitivinícola do Alentejo (Sul de Portugal). A região está sujeita a situações de seca mais frequentes e severas, enquanto a
área regada continua em expansão, o que pressiona os recursos hídricos locais e regionais. Além disso, as condições climáticas altamente variáveis
e a maior tendência para eventos climáticos extremos (e.g. ondas de calor) colocam desafios ao setor vitivinícola no Sul de Portugal. Concluímos
que a informação quantitativa relativa ao uso e gestão de água não está sempre facilmente disponível, limitando a otimização de estratégias e/ou
políticas para o uso da água ao nível da vinha, da adega e da região. Dados atualizados e indicadores robustos podem ajudar a caracterizar melhor
o uso de água e a geração de água residual na região vitivinícola do Alentejo, otimizando a gestão na vinha e na adega, ao nível da empresa e da
região. O artigo centra-se num cenário de produtor-engarrafador (“Farm-Winery”), que é o mais comum no setor vitivinícola no Sul de Portugalinfo:eu-repo/semantics/publishedVersio
Modulation of Bone Marrow Primary Cell Osteoblastogenesis and Cell Senescence by Mechanical Stimulation
Cell and animal studies conducted onboard the International Space Station and formerly the Shuttle flights have provided groundbreaking data illuminating the deleterious biological response of bone to mechanical unloading. Specifically CDKN1A/p-21 a cell senescence protein, was found to be upregulated in osteoprecursor cells of the femur during 15-day spaceflight, leading to the working hypothesis that CDKN1A/p-21 plays a role in inhibition of bone formation via mechanical regulation. To evaluate this hypothesis, utilizing a p-21 knockout mouse-line and relevant wildtype control, we cultured femoral bone marrow primary cells under unloaded (static) and cyclically stretched loading through a 30 day osteoblastogenesis protocol. Morphologic evaluation of the cultures demonstrated that mechanical stretching aligned the cells and increased the presence of defined focal adhesion expressing talin, integrin v3, and PTK2 protein tyrosine kinase 2, also known as focal adhesion kinase (FAK) in both mouse strains. In corroboration with previous investigations of cell survival signals relation to FAK, our study found that with greater concentration of focal adhesions via stretch stimulation the live cell percentage was significantly higher than the unloaded controls (p-21 knockout line: +49.70%, p*=0.009, wildtype control: +18.14%, p*=.01). Also evaluated was the mineralization and ECM secretion capability of the differentiating cells. Von Kossa staining has shown that in the p-21 knockout cells unloaded cells produce more matrix that the stretch stimulated, however the matrix is unorganized presenting in sporadic nodules covering approximately 30% of the culture area at day 14 (n=6 wells) while the stretch stimulated cultures have less mineralization content the surface area containing mineralized matrix is greater (~68% at day 14). Q-PCR evaluation of the p-21 knockout cells revealed that canonical (-catenin cascade) and non-canonical wnt11 and downstream planar cell polarity (wnt/PCP) pathway molecule RAC1 are prevalently upregulated with mechanical stimulation. Immunofluorescence for -catenin and RAC1 showed co-localization at the nuclear membrane of the p-21 knockout cells but not the wildtype (n=1) suggesting that molecular communication via the canonical and wnt/PCP pathway are initiated by mechanical loading and experience regulation along the signaling cascade by CDKN1A/p-21. Future investigations will further elucidate this relationship and provide causal data demonstrating mechanical loadings modulatory effect on p-21 expression change
Diagnóstico laboratorial de raiva em quirópteros realizado em área metropolitana na região sudeste do Brasil
No período de janeiro de 1988 adezembro de 1992, foi realizado diagnóstico de raiva em 289 morcegos através das técnicas de imunofluorescência direta e de inoculação intracerebral em camundongos. Dois morcegos insetívoros da espécie Nyctinomops macrotis se apresentaram positivos, representando 0,69% da amostra. Esses morcegos foram capturados, ainda vivos, em 1988 e 1990, na sala de um apartamento no sétimo andar e no muro de uma casa, respectivamente. Ambos em bairros residenciais. Apresentaram período de incubação de 13 e 11 dias, respectivamente, na prova biológica. A existência de morcegos insetívoros infectados com o vírus da raiva é preocupante, uma vez que essa população parece ser cada vez mais freqüente em áreas urbanas, porém isto não justifica ações predatórias indiscriminadas contra as espécies, principalmente levando-se em consideração a importância do morcego no equilíbrio ecológico da população de insetos, abundante em área urbana.Between January, 1988 and December, 1992 the S. Paulo Animal Disease Control Center subjected 289 bats to rabies examinations, utilizing the direct immunofluorescence and biological techniques. Two insectivorous bats belonging to the species Nyctinomopsmacrotis, representing 0.69% of the total sample, tested positive. Both animals had been captured alive in residential neighborhoods of the city, one in 1988 in the living room of a 7' th floor apartment and the other in 1990 on top of a wall surrounding a private house. In the biological tests, the disease showed incubation periods of 13 and 11 days respectively.Although the existence of infected insectiverous bats in urban areas is cause for concern, indiscriminate predatory action against such species can in no way be justified-particularly bearing in mind their importance in preserving the ecological balance of the insect population so prevalent in cities
Educação em saúde para alunos de primeiro grau: avaliação de material para ensino e profilaxia da esquistossomose
Considering the importance of information about schistosomiasis for students 7-15 years old, age groups at risk of exposure to the disease and whose habits contribute to its spread, a brochure based on a literary text was elaborated and applied in schools situated within an isolated focus of the disease in Rio de Janeiro, Brazil. A method to make use of the material to be employed by the teachers was successful in the learning of concepts and primary care of schistosomiasis. The use of this method is proposed also in relation to other parasitic diseases to be applied in characteristically endemic areas.Considerando a importância da informação sobre a esquistossomose para alunos de 7 a 15 anos, faixa etária apontada como de alta prevalência em regiões endêmicas e cujos hábitos colaboram para a disseminação da doença, foi elaborado um material de ensino baseado em um texto de conotação literária, o qual foi aplicado em escolas de região considerada foco isolado da doença no Município do Rio de Janeiro (Brasil). Desenvolveu-se uma metodologia de uso do material a ser empregada pelos professores, que resultou eficaz em promover aprendizagem de conceitos e cuidados básicos em relação à esquistossomose. Propõe-se o uso deste processo para outras doenças parasitárias a serem testadas em áreas caracteristicamente endêmicas
An exploratory cluster randomised controlled trial of knowledge translation strategies to support evidence-informed decision-making in local governments (The KT4LG study)
Background: Childhood overweight and obesity is the most prevalent and, arguably, politically complex child health problem internationally. Governments, communities and industry have important roles to play, and are increasingly expected to deliver an evidence-informed system-wide prevention program. However, efforts are impeded by a lack of organisational access to and use of research evidence. This study aims to identify feasible, acceptable and ideally, effective knowledge translation (KT) strategies to increase evidence-informed decision making in local governments, within the context of childhood obesity prevention as a national policy priority.Methods/Design: This paper describes the methods for KT4LG, a cluster randomised controlled trial which is exploratory in nature, given the limited evidence base and methodological advances. KT4LG aims to examine a program of KT strategies to increase the use of research evidence in informing public health decisions in local governments. KT4LG will also assess the feasibility and acceptability of the intervention. The intervention program comprises a facilitated program of evidence awareness, access to tailored research evidence, critical appraisal skills development, networking and evidence summaries and will be compared to provision of evidence summaries alone in the control program. 28 local governments were randomised to intervention or control, using computer generated numbers, stratified by budget tertile (high, medium or low). Questionnaires will be used to measure impact, costs, and outcomes, and key informant interviews will be used to examine processes, feasibility, and experiences. Policy tracer studies will be included to examine impact of intervention on policies within relevant government policy documents.Discussion: Knowledge translation intervention studies with a focus on public health and prevention are very few in number. Thus, this study will provide essential data on the experience of program implementation and evaluation of a system-integrated intervention program employed within the local government public health context. Standardised programs of system, organisational and individual KT strategies have not been described or rigorously evaluated. As such, the findings will make a significant contribution to understanding whether a facilitated program of KT strategies hold promise for facilitating evidence-informed public health decision making within complex multisectoral government organisations.<br /
The Omics of Stem Cell Mediated Regeneration: A Pilot Single Cell RNA-Seq Study of Mechanotransduction
Mechanical forces are potent modulators of stem cell based tissue regenerative mechanisms, inducing cell fate decisions and tissue specific commitment. A unique platform for investigating mechanotransduction is spaceflight, where microgravity and altered fluid mechanics provide a loading-null experimental condition. Seminal investigations of regenerative capacity in a wholly regenerative species, the newt model, and in a variety of totipotent and adult stem cell populations have demonstrated the detrimental effects of unloading on maintenance of stem cell based regeneration. Of particular interest is the observation that unloading interferes with the transition of stem cell pools from proliferative state to differentiation commitment. In this work we sought to test the hypothesis that gravity mechanotransduction regulates stem cell tissue regenerative processes by modulating stem cell proliferation and differentiation fates at specific cell cycle stages. To do this, clonally-derived ESCs were plated on a collagen matrix and expanded for 36 hours before re-plating on a non-adherent culture dish in the absence of leukemia inhibitory factor (LIF) to form spheroid aggregate EBs. After formation, the EBs were transferred to a collagen matrix coated culture dishes and given 4 days to allow implantation and outgrowth. In parallel, totipotent ESCs were plated 24 hours before mechanical stimulation on collagen matrix culture dishes in the presence of LIF to maintain totipotency and serve as un-differentiation committed controls. The EBs and ESCs were then subjected to either a 60 minute pulse of gravity (static loading) or 60 minutes of cyclic stretch (dynamic loading) mechanotransduction. Six hours post-stimulation, we used a 10X Genomics Single Cell controller to generate bar-coded single cell Illumina libraries and sequenced expressomes for 5,000 static loaded cells, representative of a change in gravity mechanotransduction, 5,000 dynamic loaded cells, representative of tissue loading associate with physiologic function, and 5,000 unstimulated 1g control cells. The comparison of these 3 libraries by cluster assignment based on like gene expression patterns show substantial alteration in cluster geometry due to mechanical loading. Specifically the mechanically loaded EB outgrowth cells to retain potency markers (PAX6, SOX2, CD34) and suppress early commitment markers (Dhh, VCAN, Igf1). Whereas the EBs cultured under the non-stimulated conditions display clear departure from the ESC expressome with lineage commitment markers upregulated and several tissue specific markers being expressed (BMP "early musculoskeletal development, Mesp1" early cardiovascular cell lineage). These markers are not seen in the mechano-stimulated cultures or the totipotent ESC cultures. Comparison of like clusters between our experimental conditions revealed an array of regenerative and stem cell genes are significantly mechano-regulated. Of particular importance CDKN1a/p21, a gene shown by previous investigation of our research team to be significantly upregulated in unloading, was suppressed in the static and dynamic loaded EBS. In addition to CDKN1a/p21 many genes related to cell cycle and transitory differentiation markers had elevated expression in the mechano-stimulated EBs, but surprisingly these trends were not observed in the ESC cultures. This study is the first of its kind investigating for mechano-signaling and mechano-regulated pathways, and has alr
Altered Hypercoagulability Factors in Patients with Chronic Chagas Disease: Potential Biomarkers of Therapeutic. Response
Thromboembolic events were described in patients with Chagas disease without cardiomyopathy. We aim to confirm if there is a hypercoagulable state in these patients and to determine if there is an early normalization of hemostasis factors after antiparasitic treatment. Ninety-nine individuals from Chagas disease-endemic areas were classified in two groups: G1, with T.cruzi infection (n = 56); G2, healthy individuals (n = 43). Twenty-four hemostasis factors were measured at baseline. G1 patients treated with benznidazole were followed for 36 months, recording clinical parameters and performance of conventional serology, chemiluminescent enzyme-linked immunosorbent assay (trypomastigote-derived glycosylphosphatidylinositol-anchored mucins), quantitative polymerase chain reaction, and hemostasis tests every 6-month visits. Prothrombin fragment 1+2 (F1+2) and endogenous thrombin potential (ETP) were abnormally expressed in 77% and 50% of infected patients at baseline but returned to and remained at normal levels shortly after treatment in 76% and 96% of cases, respectively. Plasmin-antiplasmin complexes (PAP) were altered before treatment in 32% of G1 patients but normalized in 94% of cases several months after treatment. None of the patients with normal F1+2 values during follow-up had a positive qRT-PCR result, but 3/24 patients (13%) with normal ETP values did. In a percentage of chronic T. cruzi infected patients treated with benznidazole, altered coagulation markers returned into normal levels. F1+2, ETP and PAP could be useful markers for assessing sustained response to benznidazole
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