3,529 research outputs found
Foot-and-mouth disease in Tanzania from 2001 to 2006.
Foot-and-mouth disease (FMD) is endemic in Tanzania, with outbreaks occurring almost each year in different parts of the country. There is now a strong political desire to control animal diseases as part of national poverty alleviation strategies. However, FMD control requires improving the current knowledge on the disease dynamics and factors related to FMD occurrence so control measures can be implemented more efficiently. The objectives of this study were to describe the FMD dynamics in Tanzania from 2001 to 2006 and investigate the spatiotemporal patterns of transmission. Extraction maps, the space-time K-function and space-time permutation models based on scan statistics were calculated for each year to evaluate the spatial distribution, the spatiotemporal interaction and the spatiotemporal clustering of FMD-affected villages. From 2001 to 2006, 878 FMD outbreaks were reported in 605 different villages of 5815 populated places included in the database. The spatial distribution of FMD outbreaks was concentrated along the Tanzania-Kenya, Tanzania-Zambia borders, and the Kagera basin bordering Uganda, Rwanda and Tanzania. The spatiotemporal interaction among FMD-affected villages was statistically significant (P≤0.01) and 12 local spatiotemporal clusters were detected; however, the extent and intensity varied across the study period. Dividing the country in zones according to their epidemiological status will allow improving the control of FMD and delimiting potential FMD-free areas
IFMIF suitability for evaluation of fusion functional materials
The International FusionMaterials Irradiation Facility (IFMIF) is a future neutron source based on the D-Li stripping reaction, planned to test candidate fusionmaterials at relevant fusion irradiation conditions. During the design of IFMIF special attention was paid to the structural materials for the blanket and first wall, because they will be exposed to the most severe irradiation conditions in a fusion reactor. Also the irradiation of candidate materials for solid breeder blankets is planned in the IFMIF reference design.
This paper focuses on the assessment of the suitability of IFMIF irradiation conditions for testing functionalmaterials to be used in liquid blankets and diagnostics systems, since they are been also considered within IFMIF objectives. The study has been based on the analysis and comparison of the main expected irradiation parameters in IFMIF and DEMO reactor
APPROXIMATION OF LIMIT STATE SURFACES IN MONOTONIC MONTE CARLO SETTINGS
International audienceThis article investigates the theoretical convergence properties of the estimators produced by a numerical exploration of a monotonic function with multivariate random inputs in a structural reliability framework.The quantity to be estimated is a probability typically associated to an undesirable (unsafe) event and the function is usually implemented as a computer model. The estimators produced by a Monte Carlo numerical design are two subsets of inputs leading to safe and unsafe situations, the measures of which can be traduced as deterministic bounds for the probability. Several situations are considered, when the design is independent, identically distributed or not, or sequential. As a major consequence, a consistent estimator of the (limit state) surface separating the subsets under isotonicity and regularity arguments can be built, and its convergence speed can be exhibited. This estimator is built by aggregating semi-supervized binary classifiers chosen as constrained Support Vector Machines. Numerical experiments conducted on toy examples highlight that they work faster than recently developed monotonic neural networks with comparable predictable power. They are therefore more adapted when the computational time is a key issue
A metabolic switch on a yeast arrestin connects glucose signaling to transporter endocytosis
Endocytosis is a critical component of plasma membrane dynamics, by allowing the removal of proteins such as transporters or receptors in response to environmental cues. In yeast, transporter endocytosis requires their ubiquitylation at the plasma membrane by the Nedd4-like E3 ubiquitin ligase, Rsp5. Since the ubiquitylation of a given transporter occurs only in response to specific signals, this raises the question of how substrate specificity is achieved, and how it is regulated dynamically. Various "adaptor" proteins were
identified, which may promote the interaction between Rsp5 and its substrates, and may provide a basis for this regulation. However, how they modulate Rsp5 function in response to extracellular stimuli is unknown.
We addressed this question by studying a model transporter, Jen1, which is a lactate transporter induced in the presence of lactate and endocytosed in response to glucose (Paiva et al., JBC 2009). We identified an Rsp5 adaptor protein that belongs to the alpha-arrestin family, Art4 (also named Rod1), as essential for Jen1 ubiquitylation and endocytosis of in response to
glucose. Interestingly, when cells are grown in lactate medium to induce Jen1 expression, Art4 is strongly phosphorylated by the yeast AMPK homologue, Snf1. Addition of glucose, known to trigger Jen1 endocytosis, leads to a rapid dephosphorylation of Art4, a process that requires the PP1 phosphatase regulatory subunit Reg1. This dephosphorylation allows Art4 ubiquitylation by Rsp5, and we provide details on the molecular mechanism of this regulation. We also show that Art4
ubiquitylation is required for Jen1 endocytosis. Therefore, a switch in Art4 post-translational modifications occurs in response
to glucose and is required to modulate its function as an adaptor of Rsp5. This establishes yeast arrestin-like proteins as key regulators of transporter endocytosis in response to extracellular signals
Opinion of associate professors and full professors regarding the criteria and standards for the accreditation of spanish university teachers
Este estudio descriptivo analiza la importancia que Profesores Titulares de Universidad
y Catedráticos de Universidad de España otorgan a distintos indicadores de
evaluación docente, examinándose además las diferencias entre ambos cuerpos docentes.
Una muestra representativa de 1.294 Profesores Titulares y Catedráticos de
Universidad españoles respondieron a una encuesta enviada por correo electrónico.
Los resultados señalan que los indicadores más valorados tienen que ver con la investigación
y muestran escasas diferencias entre ambos cuerpos docentes, lo que supone
una ventaja para la fi abilidad y objetividad del proceso de acreditación y concurso de
acceso a los cuerpos de funcionarios docentes universitarios en España.This descriptive study analyses and compares the importance given by Associate
Professors and Full Professors of Spanish universities to different academic evaluation
indicators. A representative sample consisting of 1294 Associate Professors and Full
Professors from Spain answered a survey sent to them by e-mail. The results show that
the most valued indicators are related to research work and reveal little difference
between the criteria of the two study groups. The latter is an advantage with respect to
the reliability and objectivity of the accreditation process and selection of tenured
university professors in Spain.Estudio fi nanciado por la Dirección General de Universidades (Referencia: EA2006-0017)
Expression, purification and bioactivity of recombinant human bone morphogenetic protein-4,-9,-10,-11 and-14 produced in Escherichia coli for tissue engineering applications
[Excerpt] Bone morphogenetic proteins (BMPs) are cytokines from the TGFb superfamily, with important roles during embryonic development and in inducing bone and cartilage in the adult body. In this contribution, we report the expression of recombinant human BMP-4, BMP-9, BMP-10, BMP-11 (or growth differentiation
factor-11, GDF-11) and BMP-14 (GDF-5), using Escherichia coli pET-25b expression system. The BMPs were purified by affinity chromatography and its bioactivity accessed in C2C12 cell line, by screening the expression of osteogenic markers with RT-PCR. [...]Fundação para a Ciência e Tecnologia for PhD grant SFRH/BD/17049/2004 and project ElastM POCI/CTM/
57177/2004 supported by FEDER and the Fundação para a Ciência e Tecnologia; European STREP Project HIPPOCRATES (NMP3-CT-2003-505758). The work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283).info:eu-repo/semantics/publishedVersio
Expression, purification and osteogenic bioactivity of recombinant human BMP-4, -9, -10, -11 and -14
Bone morphogenetic
proteins
(BMPs) are cytokines
from the TGF-b superfamily,
with important
roles during
embryonic
development
and in the induction
of bone and cartilage
tissue
differentiation
in the adult body.
In this contribution,
we report the expression
of recombinant human BMP-4, BMP-9, BMP-10, BMP-11 (or
growth differentiation
factor-
11, GDF-11) and BMP-14 (GDF-5), using Escherichia
coli pET-25b vector.
BMPs
were overexpressed,
purified
by affinity
his-tag chromatography
and shown to induce the expression
of early
markers
of bone differentiation
(e.g. smad-1, smad-5, runx2/cbfa1, dlx5, osterix,
osteopontin,
bone sialoprotein
and alkaline
phosphatase)
in C2C12 cells and in human adipose
stem cells. The described approach is a
promising
method for producing
large amounts of different
recombinant BMPs that show potential for novel
biomedical
applications.The author wishes to acknowledge the Sanger Institute for kindly offering the bacterial clones for cloning of human BMP-9 to -14. This work was supported by Fundacao para a Ciencia e Tecnologia (PhD grant SFRH/BD/17049/2004, project ElastM POCI/CTM/57177/2004 funded by FEDER and the Fundacao para a Ciencia e Tecnologia; and European STREP Project HIPPOCRATES (NMP3-CT-2003-505758). This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)
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