2,570 research outputs found
Turning it inside out: The organization of human septin heterooligomers.
Septin family proteins are quite similar to each other both within and between eukaryotic species. Typically, multiple discrete septins co-assemble into linear heterooligomers (usually hexameric or octameric rods) with a variety of cellular functions. We know little about how incorporation of different septins confers different properties to such complexes. This issue is especially acute in human cells where 13 separate septin gene products (often produced in multiple forms arising from alternative start codons and differential splicing) are expressed in a tissue-specific manner. Based on sequence alignments and phylogenetic criteria, human septins fall into four distinct groups predictive of their interactions, that is, members of the same group appear to occupy the same position within oligomeric septin protomers, which are "palindromic" (have twofold rotational symmetry about a central homodimeric pair). Many such protomers are capable of end-to-end polymerization, generating filaments. Over a decade ago, a study using X-ray crystallography and single-particle electron microscopy deduced the arrangement within recombinant heterohexamers comprising representatives of three human septin groups-SEPT2, SEPT6, and SEPT7. This model greatly influenced subsequent studies of human and other septin complexes, including how incorporating a septin from a fourth group forms heterooctamers, as first observed in budding yeast. Two recent studies, including one in this issue of Cytoskeleton, provide clear evidence that, in fact, the organization of subunits within human septin heterohexamers and heterooctamers is inverted relative to the original model. These findings are discussed here in a broader context, including possible causes for the initial confusion
Estabilidade de agregados e distribuição de carbono e nutrientes em Argissolo sob adubação orgânica e mineral.
O objetivo deste trabalho foi avaliar o impacto da adubacao organica e mineral sobre a estabilidade de agregados e a distribuicao de C, N e P, em classes de agregados de um Argissolo Vermelho-Amarelo. Os tratamentos consistiram de 0 e 40 m3 ha.1 por ano de adubacao organica e de 0, 250 e 500 kg ha.1 de adubacao mineral N.P.K da formula 4.14.8. Uma area sob floresta atlantica foi utilizada como referencia. Amostras foram coletadas nas camadas de 0.10 e 10.20 cm. Houve predominio da classe de agregados entre 4 e 2 mm, que correspondeu a 39,7% do total de agregados separados por via seca no tratamento com composto organico. Os teores de C organico total para adubacao organica foram 17,5 e 36,7% maiores para as classes 4.2 e 0,105.0,25 mm. A adubacao organica contribuiu para teores de N e P totais de 43 e 38,7% (0.10 cm) e 35,4 e 36,8% (10.20 cm), maiores que os dos tratamentos sem adubo organico. A relacao carbono/nitrogenio se manteve constante entre as classes de agregados de um mesmo tratamento, enquanto a de carbono/fosforo reduziu com o uso de adubo organico ou mineral, em relacao a mata nativa. Os indices de estabilidade de agregados se correlacionaram positivamente aos teores de carbono organico total da classe 4.2 mm
Low-cost multi-spectral camera platform for in-flight near real-time vegetation index computation and delivery.
Agricultural optimization and increased productivity is always a growing concern, due to the increasing population. Crops susceptible to a wide variety of hindering conditions, need to be carefully observed and managed to guarantee maximum production. Many diseases, weather changes, soil variances and other in?uencing factors are only visible after the plant has reached a deplorable state and its neighbors closely trailing behind. Ongoing research is enhancing an observation model that can better prevent such factors, but many still present a variety of limiting factors that are still being studied. Vegetation indices is a long dated studied concept that has proven to be able to show plant response to stress before visible signs are present. To take advantage of this we propose a multi-spectral camera, aimed at mass use, to provide the needed observation with top of the line, reliable results. The built prototype was put through two different tests, both showing it capable of displaying plant health. The ?ne control test showed the camera capable of displaying difference in plant health after only two days of stress. The results were reached with out the use of expensive lenses/?lters, and provide easy to interpret results. All while being able to send data to a nearby portable device
Estudo de raízes de coqueiro anão verde em neossolos quartzarênicos da Fazenda São João, em Petrolina-PE.
O estudo foi desenvolvido em Neossolo Quartzarênico, que tem 96% de areia, 2% de silte e 2% de argila em área de plantio comercial da Fazenda São João, município de Petrolina - PE; cultivada com coqueiro anão ecotipo verde, com idade de 7 anos; plantado no espaçamento quiconcial de 7,5 x 7,5 x 7,5 metros, irrigado por microaspersão. Para irrigação utilizou-se um emissor por planta que disponibiliza uma vazão média de 40 L/h, para uma pressão de 204,00 kPa, com uma percentagem de área molhada de 48,70%. Duas plantas foram escolhidas como representativas da área para análise de distribuição de raízes no solo. Os resultados obtidos permitem estabelecer, que até a distância de 2,40 m do caule, estão concentrados 98,17% da área acumulada das raízes. No que se refere à profundidade e até a distância de 2,40 m, menos de 6% das raízes estão abaixo de 1,20 m. As raízes mais compridas e as de maior área estão localizadas entre 0,20 e 0,60 m de profundidade numa sequência crscente até a distância de 1,80 m
Evaluation of Microencapsulation of The UFV-AREG1 Bacteriophage in Alginate-Ca Microcapsules using Microfluidic Devices
The indiscriminate use of antibiotics and the emergence of resistant
microorganisms have become a major challenge for the food industry. The purpose
of this work was to microencapsulate the bacteriophage UFV-AREG1 in a calcium
alginate matrix using microfluidic devices and to study the viability and
efficiency of retention. The microcapsules were added to gel of propylene
glycol for use as an antimicrobial in the food industry. The technique showed
the number of the phage encapsulation, yielding drops with an average 100-250
m of diameter, 82.1 2% retention efficiency and stability in the gel
matrix for 21 days. The gel added to the microencapsulated phage showed
efficiency (not detectable on the surface) in reducing bacterial contamination
on the surface at a similar level to antimicrobial chemicals (alcohol 70%).
Therefore, it was possible to microencapsulate bacteriophages in alginate-Ca
and apply the microcapsules in gels for use as sanitizers in the food industry.Comment: 8 pages, 5 figure
Quantum equivalence between the self-dual and the Maxwell-Chern-Simons models nonlinearly coupled to U(1) scalar fields
The use of master actions to prove duality at quantum level becomes
cumbersome if one of the dual fields interacts nonlinearly with other fields.
This is the case of the theory considered here consisting of U(1) scalar fields
coupled to a self-dual field through a linear and a quadratic term in the
self-dual field. Integrating perturbatively over the scalar fields and deriving
effective actions for the self-dual and the gauge field we are able to
consistently neglect awkward extra terms generated via master action and
establish quantum duality up to cubic terms in the coupling constant. The
duality holds for the partition function and some correlation functions. The
absence of ghosts imposes restrictions on the coupling with the scalar fields.Comment: 13 pages, no figure
Detecção de ovino sororreagente para Maedi-Visna no estado de Sergipe.
Resumo - O vírus da Maedi-Visna pertence à família Retroviridae, gênero Lentivírus e afeta ovinos criados especialmente de forma intensiva. Apesar de variável patogenicidade, é responsável por manifestação clínica crônica e debilitante. Amplamente distribuído pelo mundo, é relacionado a subestimado impacto econômico na ovinocultura, porém com dados imprecisos no Brasil. O presente trabalho objetivou a obtenção da prevalência da Maedi-Visna no município de Lagarto/Sergipe. Foram analisadas 151 amostras séricas de ovinos Santa Inês, oriundas de nove propriedades rurais, identificadas quanto ao sexo e idade dos animais. Utilizou-se o teste de Imunodifusão em Gel de Ágar através da técnica de microaglutinação. A prevalência obtida foi de 0,66%, o que representa o primeiro relato da Maedi-Visna em Sergipe e que pode estar correlacionado ao íntimo contato entre ovinos e caprinos ou a submissão dos animais às exposições agropecuárias, inclusive extra-estaduais, onde há a aproximação de animais infectados e sadios promovida de forma inconsciente pelos produtores, ou ainda à transmissão a partir de animais exóticos inseridos em rebanho para melhoramento genético. Devido ao sistema de criação ao qual os animais são mantidos, confinamento de reprodutores e regime semi-intensivo aos demais, a doença pode não ter conseguido condições propicias para disseminar-se. O resultado indica riscos à ovinocultura desenvolvida no estado e as relações comerciais com os demais, e sugere a necessidade de estudos mais amplos para melhor caracterizar o perfil do estado em relação à ocorrência de Lentiviroses de Pequenos Ruminantes e implantação de medidas de controle e prevenção da disseminação desta enfermidade. Detection of sheep sororeaction for maedi-visna in State of Sergipe. Abstract - The virus of Maedi Visna belongs to Retroviridae family, gender Lentivirus affects raise of sheep especially at intensive way. Despite variable pathogenicity, is responsible for chronic and debilitating clinical. Widely distributed throughout the world, is linked underestimated the economic impact in raise of sheep, but with inaccurate data in Brazil. This study aimed to obtain the prevalence of Maedi Visna in the municipality of Lagarto / Sergipe. It were analyzed 151 samples of serum taken from sheep of Santa Ines breed, from nine farms, identified as to sex and age of animals. It was used in the test of Imunodifusion in Agar Gel whith microaglutination technique. The prevalence obtained was 0.66%, which represents the first report of Maedi Visna in Sergipe and can be correlated to the close contact between sheep and goats or the submission of animals for agricultural exhibitions where there is the nearest of infected and healthy animals unconscious promoted by producers or the transmission from exotic animals entered in farms for breeding herd. Because the system of creation which animals are kept, confinement of males and semi-intensive system to the others, the disease may not have achieved favorable conditions to spread itself. The results indicates the risk in raised of sheep developed in the state and trade relations with the others, and suggests the need for more extensive studies to better characterize the profile of the state in relation to the occurrence of Lentiviroses of Small Ruminants and implementation of measures for control and prevention spread of this disease
Decisional tool for cost of goods analysis of bioartificial liver devices for routine clinical use
BACKGROUND AIMS: Bioartificial liver devices (BALs) are categorized as advanced therapy medicinal products (ATMPs) with the potential to provide temporary liver support for liver failure patients. However, to meet commercial demands, next-generation BAL manufacturing processes need to be designed that are scalable and financially feasible. The authors describe the development and application of a process economics decisional tool to determine the cost of goods (COG) of alternative BAL process flowsheets across a range of industrial scales. METHODS: The decisional tool comprised an information database linked to a process economics engine, with equipment sizing, resource consumption, capital investment and COG calculations for the whole bioprocess, from cell expansion and encapsulation to fluidized bed bioreactor (FBB) culture to cryopreservation and cryorecovery. Four different flowsheet configurations were evaluated across demands, with cell factories or microcarriers in suspension culture for the cell expansion step and single-use or stainless steel technology for the FBB culture step. RESULTS: The tool outputs demonstrated that the lowest COG was achieved with microcarriers and stainless steel technology independent of the annual demand (1500-30 000 BALs/year). The analysis identified the key cost drivers were parameters impacting the medium volume and cost. CONCLUSIONS: The tool outputs can be used to identify cost-effective and scalable bioprocesses early in the development process and minimize the risk of failing to meet commercial demands due to technology choices. The tool predictions serve as a useful benchmark for manufacturing ATMPs
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