7,345 research outputs found
Drosophila happyhour modulates JNK-dependent apoptosis
Mitogen-activated protein kinase kinase kinase kinase-3 (MAP4K3) is a Ste20 kinase family member that modulates multiple signal transduction pathways. We recently identified MAP4K3 as proapoptotic kinase using an RNA interference screening approach. In mammalian cells, MAP4K3 enhances the mitochondrial apoptosis pathway through the post-transcriptional modulation of selected proapoptotic Bcl-2 homology domain 3-only proteins. Recent data suggest that MAP4K3 mutations contribute to pancreatic cancer, which highlights the importance of studying the in vivo function of this kinase. To determine whether the cell death function is conserved in vivo and which downstream signalling pathways are involved, we generated transgenic flies expressing happyhour (hppy), the Drosophila MAP4K3 orthologue. Here, we show that the overexpression of hppy promotes caspase-dependent apoptosis and that the hypothetical kinase domain is essential for inducing cell death. In addition, we show that hppy expression triggers the activation of both the c-Jun N-terminal kinase (JNK) and target of rapamycin (TOR) signalling pathways; however, only JNK signalling is required for apoptosis. Together, our results show that hppy has a JNK-dependent proapoptotic function in Drosophila, which reinforces the hypothesis that MAP4K3 might act as tumour suppressor by regulating apoptosis in higher eukaryotes
Efeito de diferentes fontes energéticas da dieta sobre a produção de metano utilizando a técnica de fermentação ruminal ex situ (microrúmen).
O objetivo do experimento foi avaliar o efeito de diferentes fontes energéticas da dieta sobre a fermentação ruminal em bovinos. O delineamento adotado foi o quadrado latino 3x3 replicado, com período de 16 dias e 3 tratamentos: Controle: Dieta de baixo extrato etéreo; Soja: Dieta de alto extrato etéreo (inclusão de 15% de soja grão); Polpa: Dieta de baixo extrato etéreo e alta participação de pectina (inclusão de 15% de polpa cítrica). As coletas de conteúdo ruminal foram realizadas no 16º dia experimental, sendo realizadas antes, 3, 6, 9 e 12 horas após a alimentação matinal. Utilizou-se a técnica de fermentação ruminal ex situ, a qual consiste em incubar frascos de penicilina contendo conteúdo ruminal sólido e líquido em banho termostático por 30min. Após a incubação era realizada a mensuração de metano e ácidos graxos de cadeia curta por cromatografia gasosa. A partir desta técnica consegue-se estimar a produção de ácidos graxos de cadeia curta, metano e a perda de energia realtiva (PER). A PER estima a eficiência da fermentação dos alimentos, ou seja, com ela é possível avaliar a perda de metano em relação aos outros produtos da fermentação. A Polpa aumentou a produção de acético e butírico e a dieta Soja diminuiu os mesmos ácidos graxos de cadeia curta. Nenhuma das dietas alterou a produção de metano ou a perda de energia relativa ao metano
Renormalization group flow with unstable particles
The renormalization group flow of an integrable two dimensional quantum field
theory which contains unstable particles is investigated. The analysis is
carried out for the Virasoro central charge and the conformal dimensions as a
function of the renormalization group flow parameter. This allows to identify
the corresponding conformal field theories together with their operator content
when the unstable particles vanish from the particle spectrum. The specific
model considered is the -homogeneous Sine-Gordon model.Comment: 5 pages Latex, 3 figure
Tacrolimus, a forgotten agent in kidney transplant leukopenia
Leukopenia in kidney transplant patients is frequent, it causes potentially life-threatening complications, but it is often poorly characterized. Opportunistic infections, immunologic disturbances and drug-related toxicity are principal causes of single or multilineage cytopenias. Tacrolimus-induced leukopenia is a less recognized but frequent complication.
We describe one patient with leukopenia developing within seven months after renal transplant. After excluding other potential causes, tacrolimus was switched to cyclosporine, with recovery of white blood cell count.
Based on the clinical report, the authors reviewed causes of post-transplant leukopenia, focusing on the diagnostic investigation. Early diagnosis and interventions are fundamental to improve prognosis
Stripes, Vibrations and Superconductivity
We propose a model of a spatially modulated collective charge state of
superconducting cuprates. The regions of higher carrier density (stripes) are
described in terms of Luttinger liquids and the regions of lower density as a
two-dimensional interacting bosonic gas of d_{x^2-y^2} hole pairs. The
interactions among the elementary excitations are repulsive and the transition
to the superconducting state is driven by decay processes. Vibrations of the
CCS and the lattice, although not participating directly in the binding
mechanism, are fundamental for superconductivity. The superfluid density and
the lattice have a strong tendency to modulation implying a still unobserved
dimerized stripe phase in cuprates. The phase diagram of the model has a
crossover from 1D to 2D behavior and a pseudogap region where the amplitude of
the order parameters are finite but phase coherence is not established. We
discuss the nature of the spin fluctuations and the unusual isotope effect
within the model.Comment: 51 pages, 20 figures. Post-March Meeting version: New references are
added, some of the typos are corrected, and a few new discussions are
include
Pollination ecology of Arrojadoa rhodantha (Gurk) Britton & Rose (Cactaceae) in Petrolina - PE, Brazil.
This work aimed to study the biology and floral visitors ofthis cactus in Petrolina, PE
Multi-domain interventions for dementia prevention–a systematic review
Objectives: There is a growing incidence of cognitive decline and dementia associated with the ageing population. Lifestyle factors such as diet, physical activity, and cognitive activities may individually or collectively be undertaken to increase one’s odds of preventing cognitive decline and future dementia. This study will examine whether clinical trials using multidomain lifestyle intervention can significantly decrease the risk of cognitive decline and therefore dementia. Design, Setting and Participants: This systematic literature review of multidomain lifestyle interventions for the prevention of cognitive decline and dementia followed the PRISMA guidelines. Clinical trials involving multidomain intervention (i.e., diet and physical activity, or without cognitive training) in older adults ( ≥ 49 years old) at higher risk of dementia were identified through 5 electronic databases (EMBASE, MEDLINE, CINAHL, Cochrane, and Scopus). A comprehensive search was performed to identify and retrieve publications until 15 November 2022. Trials were published in English. Results: The included studies (n=15) assessed change in cognition in response to a multidomain lifestyle intervention. However, the cognitive outcome measures used in these studies were heterogeneous. Despite this heterogeneity, two thirds of the studies showed improvement in cognition following a multidomain intervention (n=10 with a total of 9,439 participants). However, five studies reported no improvement in cognition following the multidomain intervention. The most common form of dietary intervention included higher amount of fruit and vegetable intake; whole-grain cereal products instead of refined; low fat options in milk and meat products; and limiting sucrose intake to less than 50 g/day. Most clinical trial studies were powered to examining the effects of multidomain interventions in cognition but were not designed to test the contribution of individual domains (i.e., dietary changes, increased physical activity, or increased cognitive stimulation alone). Conclusion: This systematic review aimed to determine the effect of multimodal lifestyle interventions on cognitive outcomes in older adults at risk of dementia. We found that participants with conditions that may increase the risk of dementia, (e.g., hypertension, cardiovascular fragility) do benefit from multi-modal lifestyle changes including diet, physical activity, and cognitive training. Two thirds of studies using multidomain lifestyle interventions showed improvements in cognitive function. Trials with a focus on cognitive training, dietary improvement, and physical activity may prevent or delay cognitive decline in older adults including those at risk of developing dementia. Future studies should consider longer follow-up periods and adequate power to be able to examine the effects of each lifestyle component in the context of multimodal interventions
Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)
Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade
A contribuição da Embrapa Recursos Genéticos e Biotecnologia à capacitação e formação profissional para implantação do Sistema da Qualidade.
bitstream/CENARGEN-2010/31510/1/ct080.pd
First VLT/X-shooter spectroscopy of early-type stars outside the Local Group
As part of the VLT/X-shooter science verification, we obtained the first
optical medium-resolution spectrum of a previously identified bright O-type
object in NGC55, an LMC-like galaxy at a distance of \sim2.0 Mpc. Based on the
stellar and nebular spectrum, we investigate the nature and evolutionary status
of the central object(s) and its influence on the surrounding interstellar
medium. We conclude that the source, NGC55_C1_31, is a composite object, likely
a stellar cluster, which contains one or several hot (T_eff \simeq 50000 K) WN
stars with a high mass-loss rate (\sim3 \times 10^{-5} M_\odot yr^{-1}) and a
helium-rich composition (N_He/N_H = 0.8). The visual flux is dominated by
OB-type (super)giant stars with T_eff \sim< 35000 K, solar helium abundance
(N_He/N_H = 0.1), and mass-loss rate \sim2 \times 10^{-6} M_\odot yr^{-1}. The
surrounding H II region has an electron density n_e < 10^2 cm^{-3} and an
electron temperature T(OIII) \simeq 11500 \pm 600 K. The oxygen abundance of
this region is [O/H] = 8.18 \pm 0.03 which corresponds to Z = 0.31 \pm 0.04
Z_\odot. We observed no significant gradients in T(OIII), n_e or [O/H] on a
scale of 73 pc extending in four directions from the ionising source. The
properties of the HII region can be reproduced by a CLOUDY model which uses the
central cluster as ionising source, thus providing a self-consistent
interpretation of the data. We also report on the serendipitous discovery of
HeII nebular emission associated with the nearby source NGC55_C2_35, a feature
usually associated with strong X-ray sources.Comment: 12 pages, 10 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Society; the definitive version will be available at
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