2,148 research outputs found
Developmental Acquisition of Regulomes Underlies Innate Lymphoid Cell Functionality
Innate lymphoid cells (ILCs) play key roles in host defense, barrier integrity, and homeostasis and mirror adaptive CD4(+) T helper (Th) cell subtypes in both usage of effector molecules and transcription factors. To better understand the relationship between ILC subsets and their Th cell counterparts, we measured genome-wide chromatin accessibility. We find that chromatin in proximity to effector genes is selectively accessible in ILCs prior to high-level transcription upon activation. Accessibility of these regions is acquired in a stepwise manner during development and changes little after in vitro or in vivo activation. Conversely, dramatic chromatin remodeling occurs in naive CD4(+) T cells during Th cell differentiation using a type-2-infection model. This alteration results in a substantial convergence of Th2 cells toward ILC2 regulomes. Our data indicate extensive sharing of regulatory circuitry across the innate and adaptive compartments of the immune system, in spite of their divergent developing pathways
The ortho-to-para ratio of ammonia in the L1157 outflow
We have measured the ortho-to-para ratio of ammonia in the blueshifted gas of
the L1157 outflow by observing the six metastable inversion lines from (J, K) =
(1, 1) to (6, 6). The highly excited (5, 5) and (6, 6) lines were first
detected in the low-mass star forming regions. The rotational temperature
derived from the ratio of four transition lines from (3, 3) to (6, 6) is
130-140 K, suggesting that the blueshifted gas is heated by a factor of ~10 as
compared to the quiescent gas. The ortho-to-para ratio of the NH3 molecules in
the blueshifted gas is estimated to be 1.3--1.7, which is higher than the
statistical equilibrium value. This ratio provides us with evidence that the
NH3 molecules have been evaporated from dust grains with the formation
temperature between 18 and 25 K. It is most likely that the NH3 molecules on
dust grains have been released into the gas phase through the passage of strong
shock waves produced by the outflow. Such a scenario is supported by the fact
that the ammonia abundance in the blueshifted gas is enhanced by a factor of ~5
with respect to the dense quiescent gas.Comment: 16 pages, including 3 PS figures. To appear in the ApJ (Letters).
aastex macro
SiO Emission in the Multi-Lobe Outflow associated with IRAS 16293-2422
We have mapped the thermal emission line of SiO (v = 0; J = 2-1) associated
with the quadrupolar molecular outflow driven by the very cold far-infrared
source IRAS 16293-2422. The SiO emission is significantly enhanced in the
northeastern red lobe and at the position ~50" east of the IRAS source. Strong
SiO emission observed at ~50" east of the IRAS source presents evidence for a
dynamical interaction between a part of the eastern blue lobe and the dense
ambient gas condensation, however, such an interaction is unlikely to be
responsible for producing the quadrupolar morphology. The SiO emission in the
northeastern red lobe shows the spatial and velocity structure similar to those
of the CO outflow, suggesting that the SiO emission comes from the molecular
outflow in the northeastern red lobe itself. The observed velocity structure is
reproduced by a simple spatio-kinematic model of bow shock with a shock
velocity of 19-24 km/s inclined by 30-45 deg from the plane of the sky. This
implies that the northeastern red lobe is independent of the eastern blue lobe
and that the quadrupolar structure is due to two separate bipolar outflows.
The SiO emission observed in the western red lobe has a broad pedestal shape
with low intensity. Unlike the SiO emission in the northeastern red lobe, the
spatial extent of the SiO emission in the western red lobe is restricted to its
central region. The spatial and velocity structures and the line profiles
suggest that three different types of the SiO emission are observed in this
outflow; the SiO emission arises from the interface between the outflowing gas
and the dense ambient gas clump, the SiO emission coming from the outflow lobe
itself, and the broad SiO emission with low intensity observed at the central
region of the outflow lobe.Comment: 14 pages, 6 figures (figures 1 and 4 are color), gzipped tar file, To
appear in the Ap
Structure and soft magnetic properties of sputter deposited MnZn-ferrite films
In this paper we report the soft magnetic properties of thin films of sputtered MnZn ferrite deposited on thermally oxidized Si substrates. A high deposition temperature, 600¿°C, together with the addition of water vapor to the sputtering gas was found to improve the initial ac permeability, µ. The highest value obtained was approximately 30. For MnZn-ferrite films with much larger grain sizes, as obtained by deposition on a polycrystalline Zn-ferrite substrate, a µ of 100 was obtained. The results are discussed in terms of the so-called nonmagnetic grain boundary model
A major star formation region in the receding tip of the stellar Galactic bar
We present an analysis of the optical spectroscopy of 58 stars in the
Galactic plane at \arcdeg, where a prominent excess in the flux
distribution and star counts have been observed in several spectral regions, in
particular in the Two Micron Galactic Survey (TMGS) catalog. The sources were
selected from the TMGS, to have a magnitude brighter than +5 mag and be
within 2 degrees of the Galactic plane. More than 60% of the spectra correspond
to stars of luminosity class I, and a significant proportion of the remainder
are very late giants which would also be fast evolving. This very high
concentration of young sources points to the existence of a major star
formation region in the Galactic plane, located just inside the assumed origin
of the Scutum spiral arm. Such regions can form due to the concentrations of
shocked gas where a galactic bar meets a spiral arm, as is observed at the ends
of the bars of face-on external galaxies. Thus, the presence of a massive star
formation region is very strong supporting evidence for the presence of a bar
in our Galaxy.Comment: 13 pages (latex) + 4 figures (eps), accepted in ApJ Let
Seleção de óleos essenciais repelentes à predadores e seletivos ao parasitoide Telenomus podisi (Hymenoptera: Platygastridae).
Em programas de controle biológico com parasitoides, uma das dificuldades na liberação dos parasitoides está relacionada com a predação dos ovos parasitados. O objetivo do trabalho foi selecionar repelentes aos predadores que sejam seletivos ao parasitoide Telenomus podisi. Para verificar a repelência foram confeccionadas cartelas de ovos de Euschistus heros e aplicados óleos essenciais. As cartelas foram distribuídas em cultivo de soja e retiradas após 24 hs. A avaliação foi realizada, contabilizando-se os ovos remanescentes nas cartelas. Como o óleo de canela-folha [100%] apresentou maior repelência aos predadores (75 a 96,6%), este foi aplicado, em diferentes concentrações, sobre as pupas do parasitoide e avaliou-se a sua emergência. As concentrações utilizadas foram 0, 25, 50, 75 e 100% do óleo, diluídos em solução de 30% de tween. Foi observado que o óleo afetou a emergência dos parasitoides em concentração-dependente. Mesmo a menor concentração causou mortalidade de 30%. Desse modo, como alternativa para utilização do óleo de canela-folha foram realizados testes com cápsulas de gelatina. Testes iniciais foram realizados, pois não há informações básicas sobre a liberação de parasitoides nestas condições. Foram realizados testes com as cápsulas com diferentes cores, tamanhos das cápsulas e quantidade de pupas/cápsula. A cápsula de tamanho 0 com 50% de ovos parasitados apresentou maior número de insetos emergidos; a cor presentou pouca influência na emergência dos parasitoides. Realizou-se teste a campo, para observar a proteção que as cápsulas exercem contra predadores. Assim, cápsulas com pupas foram distribuídas em cultivo de soja e recolhidas após 24 hs. Avaliou-se as pupas remanescentes (peso inicial – final) nas cápsulas. As cápsulas não apresentaram eficiência contra predadores, independente das cores utilizadas, e são extremamente sensíveis a umidade, deformando-se facilmente. Outras alternativas deverão ser estudadas para viabilizar a liberação dos parasitoides de ovos
Aspectos biológicos de Heliothis virescens (Lepidoptera: Noctuidae) alimentada com grãos verdes de milho em diferentes temperaturas.
A lagarta-da-maçã do algodão Heliothis virescens (Fabricius, 1781) (Lepidoptera: Noctuidae) é uma praga polífaga, com grande capacidade de dano em lavouras de milho devido à capacidade de alimentar-se das espigas. Apesar disso, ainda são escassas as informações sobre o desenvolvimento dessa espécie nessa cultura, o que dificulta a recomendação de estratégias de controle. Desse modo, este trabalho objetivou avaliar aspectos biológicos de H. virescens alimentada com grãos de milho em diferentes temperaturas. O delineamento experimental utilizado foi inteiramente casualizado, com 10 repetições (n=7 lagartas individualizadas/repetição). Os grãos de milho, (híbrido 2B688), no estágio grão pastoso, foram ofertados ad libitum nas temperaturas constantes de 25°, 28° e 31°C (70% UR e fotofase de 14 hs). A partir do 5° instar larval foi avaliado também o consumo (g) de grãos. Foram avaliados os parâmetros reprodutivos da fase adulta do inseto. O aumento da temperatura reduziu a fase jovem assim como o consumo de grãos de milho, que foi menor a 31ºC. Apesar disso, não se verificou diferença na viabilidade larval da praga. O peso e viabilidade de pupa não foram afetados pela temperatura, porém houve redução na duração da fase pupa-adulto aos insetos submetidos a 31ºC. Durante a fase adulta, o parâmetro de fecundidade não diferiu entre as temperaturas, porém na temperatura mais elevada (31ºC) os ovos foram 100% inviáveis. Os resultados obtidos neste estudo demonstram que H. virescens pode se alimentar dos grãos de milho e completar o seu ciclo nas três temperaturas estudadas, porém é na faixa entre 25 e 28 ºC que a praga encontra as condições ideais para o seu desenvolvimento
Morphological descriptions of laboratory reared larvae and post-larvae of the Australian shovel-nosed lobster Thenus australiensis Burton & Davie, 2007 (Decapoda, Scyllaridae)
Complete larval development from newly hatched larvae up to the juvenile stage was successfully achieved in the Australian shovel-nosed lobster Thenus australiensis under laboratory conditions. The larvae of this species passed through four phyllosoma stages (each stage has a single instar), and developed into the first juvenile stage via a post-larval, nisto stage. The shortest and mean durations from hatching to metamorphosis at a water temperature of 25°C were 32 and 38 days, respectively. Morphologies of body and appendages for all four phyllosoma stages and the nisto stage were described. The phyllosomas were fed exclusively on the jellyfish Aurelia aurita throughout their culture. Our results indicate that jellyfish may be a viable diet for T. australiensis phyllosoma's in culture and may therefore be useful for commercial-scale lobster production
The cDNA and deduced amino acid sequence of the γ subunit of the L-type calcium channel from rabbit skeletal muscle
Complementary DNAs for the γ subunit of the calcium channel of rabbit skeletal muscle were isolated on the basis of peptide sequences derived from the purified protein. The deduced primary structure is without homology to other known protein sequences and is consistent with the γ subunit being an integral membrane protein
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