92 research outputs found
Percepciones de directores y ejecutivos del Instituto Colombiano Agropecuario acerca del rol del director regional de desarrollo rural.
Se determinó si existía un conflicto entre directores y ejecutivos en la forma de percibir las funciones del Director Regional de Desarrollo Rural del Instituto. Se elaboró un cuestionario dividido en 2 secciones, la primera buscaba obtener respuesta de los funcionarios con relación a edad, último nivel académico obtenido, experiencia de trabajo con el Instituto y experiencia en Desarrollo Rural y la segunda hace referencia a las funciones que puede desempeñar el Director. Tanto directores como ejecutivos están de acuerdo con el rol que puede desempeñar en el Instituto el Director Regional de Desarrollo Rural. Las diferencias entre los grupos representados y sus respuestas se refieren más que todo al nivel en el cual están de acuerdo y no a los niveles en que no se encuentran de acuerdo. Ambos grupos percibieron que el rol de Director incluye 38 funciones del cuestionario y que tres de los enunciados no describen funciones. Existen diferencias marcadas entre ejecutivos y Directores para las características de: edad, entrenamiento y experiencia de trabajo con el Institut
Boundary Shear Acceleration in the Jet of MKN501
The high resolution image of the jet of the BL Lac object MKN501 in radio,
show a limb-brightened feature. An explanation of this feature as an outcome of
differential Doppler boosting of jet spine and jet boundary due to transverse
velocity structure of the jet requires large viewing angle. However this
inference contradicts with the constraints derived from the high energy
-ray studies unless the jets bends over a large angle immediately after
the -ray zone (close to the central engine). In this letter we propose
an alternate explanation to the limb-brightened feature of MKN501 by
considering the diffusion of electrons accelerated at the boundary shear layer
into the jet medium and this consideration does not require large viewing
angle. Also the observed difference in the spectral index at the jet boundary
and jet spine can be understood within the frame work of shear acceleration.Comment: 5 pages, accepted for publication in MNRA
Reduced engagement with social stimuli in 6-month-old infants with later Autism Spectrum Disorder: a longitudinal prospective study of infants at high familial risk
Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects more than 1% of the population, and close to 20% of prospectively studied infants with an older sibling with ASD. Although significant progress has been made in characterizing the emergence of behavioral symptoms of ASD, far less is known about the underlying disruptions to early learning. Recent models suggest that core aspects of the causal path to ASD may only be apparent in early infancy. Here, we investigated social attention in 6- and 12-month-old infants who did and did not meet criteria for ASD at 24 months using both cognitive and electrophysiological methods. We hypothesized that a reduction in attention engagement to faces would be associated with later ASD. Methods: In a prospective longitudinal design, we used measures of both visual attention (habituation) and brain function (event-related potentials to faces and objects) at 6 and 12 months, and investigated the relationship to ASD outcome at 24 months. Results: High-risk infants who met criteria for ASD at 24 months showed shorter epochs of visual attention, faster but less prolonged neural activation to faces, and delayed sensitization responses (increases in looking) to faces at 6 months; these differences were less apparent at 12 months. These findings are consistent with disrupted engagement of sustained attention to social stimuli. Conclusions: These findings suggest that there may be fundamental early disruptions to attention engagement that may have cascading consequences for later social functioning
Transport and Acceleration of Energetic Charged Particles near an Oblique Shock
We have developed a numerical simulation code that treats the transport and
acceleration of charged particles crossing an idealized oblique,
non-relativistic shock within the framework of pitch angle transport using a
finite-difference method. We consider two applications: 1) to study the
steady-state acceleration of energetic particles at an oblique shock, and 2) to
explain observed precursors of Forbush decreases of galactic cosmic rays before
the arrival of an interplanetary shock induced by solar activity. For the
former, we find that there is a jump in the particle intensity at the shock,
which is stronger for more oblique shocks. Detailed pitch angle distributions
are also presented. The simple model of a Forbush decrease explains the key
features of observed precursors, an enhanced diurnal anisotropy extending
several mean free paths upstream of the shock and a depletion of particles in a
narrow loss cone at ~0.1 mean free path from the shock. Such precursors have
practical applications for space weather prediction.Comment: 20 pages + 12 figures, aas2pp4.sty included, to appear in Astrophys.
J. (vol. 515, no. 2, April 20, 1999
Gene diversity in grevillea populations introduced in Brazil and its implication on management of genetic resources.
A variabilidade isoenzimática para seis populações de Grevillea robusta, oriundas de um teste de procedências/progenies, implantado no delineamento em blocos casualizados com 5 plantas por parcela, no Sul do Brasil, é descrita. A estrutura genética da população foi analisada utilizando-se marcadores bioquímicos, aos 5 anos de idade, especificamente para os locos MDH-3, PGM-2, DIA-2, PO-1, PO-2, SOD-1, e SKDH-1. As procedências do norte de ocorrência natural (Rathdowney e Woodenbong) apresentaram divergência genética superior, em relação à média das progênies, considerando o número de alelos por locus, (Ap), a riqueza alélica (Rs), a diversidade genética de Nei (H), e o coeficiente de endogamia (f). A endogamia foi detectada em diversos graus. A testemunha comercial apresentou o maior coeficiente de endogamia, (f = 0,4448), comparativamente à média das procedências (f = 0,2306), possivelmente devido à insuficiente amostragem populacional na região de origem (Austrália). Apesar de sua ocorrência natural restrita, observou-se correlação positiva entre divergência genética e distância geográfica entre as populações originais. A distância genética e análise de cluster, baseada no modelo bayesiano, mostrou três grupos de procedências distintos: 1) Rathdowney- QLD e Woodenbong-QLD; 2) Paddy?s Flat-NSW; e 3) Mann River-NSW, Boyd River-NSW e a testemunha comercial (material utilizado no Brasil). O agrupamento da testemunha com as procedências Mann River-NSW e Boyd River-NSW sugere um maior potencial das procedências do norte para o melhoramento genético visando à produção de madeira no Brasil, devido a sua elevada diversidade genética e baixo coeficiente de endogamia
Dual Neonate Vaccine Platform against HIV-1 and M. tuberculosis
Acquired immunodeficiency syndrome and tuberculosis (TB) are two of the
world's most devastating diseases. The first vaccine the majority of
infants born in Africa receive is Mycobacterium bovis bacillus
Calmette-Guérin (BCG) as a prevention against TB. BCG protects against
disseminated disease in the first 10 years of life, but provides a variable
protection against pulmonary TB and enhancing boost delivered by recombinant
modified vaccinia virus Ankara (rMVA) expressing antigen 85A (Ag85A) of
M. tuberculosis is currently in phase IIb evaluation in
African neonates. If the newborn's mother is positive for human
immunodeficiency virus type 1 (HIV-1), the baby is at high risk of acquiring
HIV-1 through breastfeeding. We suggested that a vaccination consisting of
recombinant BCG expressing HIV-1 immunogen administered at birth followed by a
boost with rMVA sharing the same immunogen could serve as a strategy for
prevention of mother-to-child transmission of HIV-1 and rMVA expressing an
African HIV-1-derived immunogen HIVA is currently in phase I trials in African
neonates. Here, we aim to develop a dual neonate vaccine platform against HIV-1
and TB consisting of BCG.HIVA administered at birth followed by a boost with
MVA.HIVA.85A. Thus, mMVA.HIVA.85A and sMVA.HIVA.85A vaccines were constructed,
in which the transgene transcription is driven by either modified H5 or short
synthetic promoters, respectively, and tested for immunogenicity alone and in
combination with BCG.HIVA222. mMVA.HIVA.85A was produced markerless
and thus suitable for clinical manufacture. While sMVA.HIVA.85A expressed higher
levels of the immunogens, it was less immunogenic than mMVA.HIVA.85A in BALB/c
mice. A BCG.HIVA222–mMVA.HIVA.85A prime-boost regimen induced
robust T cell responses to both HIV-1 and M. tuberculosis.
Therefore, proof-of-principle for a dual anti-HIV-1/M.
tuberculosis infant vaccine platform is established. Induction of
immune responses against these pathogens soon after birth is highly desirable
and may provide a basis for lifetime protection maintained by boosts later in
life
A Major Role of the RecFOR Pathway in DNA Double-Strand-Break Repair through ESDSA in Deinococcus radiodurans
In Deinococcus radiodurans, the extreme resistance to DNA–shattering treatments such as ionizing radiation or desiccation is correlated with its ability to reconstruct a functional genome from hundreds of chromosomal fragments. The rapid reconstitution of an intact genome is thought to occur through an extended synthesis-dependent strand annealing process (ESDSA) followed by DNA recombination. Here, we investigated the role of key components of the RecF pathway in ESDSA in this organism naturally devoid of RecB and RecC proteins. We demonstrate that inactivation of RecJ exonuclease results in cell lethality, indicating that this protein plays a key role in genome maintenance. Cells devoid of RecF, RecO, or RecR proteins also display greatly impaired growth and an important lethal sectoring as bacteria devoid of RecA protein. Other aspects of the phenotype of recFOR knock-out mutants paralleled that of a ΔrecA mutant: ΔrecFOR mutants are extremely radiosensitive and show a slow assembly of radiation-induced chromosomal fragments, not accompanied by DNA synthesis, and reduced DNA degradation. Cells devoid of RecQ, the major helicase implicated in repair through the RecF pathway in E. coli, are resistant to γ-irradiation and have a wild-type DNA repair capacity as also shown for cells devoid of the RecD helicase; in contrast, ΔuvrD mutants show a markedly decreased radioresistance, an increased latent period in the kinetics of DNA double-strand-break repair, and a slow rate of fragment assembly correlated with a slow rate of DNA synthesis. Combining RecQ or RecD deficiency with UvrD deficiency did not significantly accentuate the phenotype of ΔuvrD mutants. In conclusion, RecFOR proteins are essential for DNA double-strand-break repair through ESDSA whereas RecJ protein is essential for cell viability and UvrD helicase might be involved in the processing of double stranded DNA ends and/or in the DNA synthesis step of ESDSA
New paradigms for BRCA1/BRCA2 testing in women with ovarian cancer: results of the Genetic Testing in Epithelial Ovarian Cancer (GTEOC) study.
BACKGROUND: Over recent years genetic testing for germline mutations in BRCA1/BRCA2 has become more readily available because of technological advances and reducing costs. OBJECTIVE: To explore the feasibility and acceptability of offering genetic testing to all women recently diagnosed with epithelial ovarian cancer (EOC). METHODS: Between 1 July 2013 and 30 June 2015 women newly diagnosed with EOC were recruited through six sites in East Anglia, UK into the Genetic Testing in Epithelial Ovarian Cancer (GTEOC) study. Eligibility was irrespective of patient age and family history of cancer. The psychosocial arm of the study used self-report, psychometrically validated questionnaires (Depression Anxiety and Stress Scale (DASS-21); Impact of Event Scale (IES)) and cost analysis was performed. RESULTS: 232 women were recruited and 18 mutations were detected (12 in BRCA1, 6 in BRCA2), giving a mutation yield of 8%, which increased to 12% in unselected women aged <70 years (17/146) but was only 1% in unselected women aged ≥70 years (1/86). IES and DASS-21 scores in response to genetic testing were significantly lower than equivalent scores in response to cancer diagnosis (p<0.001). Correlation tests indicated that although older age is a protective factor against any traumatic impacts of genetic testing, no significant correlation exists between age and distress outcomes. CONCLUSIONS: The mutation yield in unselected women diagnosed with EOC from a heterogeneous population with no founder mutations was 8% in all ages and 12% in women under 70. Unselected genetic testing in women with EOC was acceptable to patients and is potentially less resource-intensive than current standard practice.This work was supported by Target Ovarian Cancer grant number T005MT.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by the BMJ Group
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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