Trithorax group proteins: switching genes on and keeping them active

Cellular memory is provided by two counteracting groups of chromatin proteins termed Trithorax group (TrxG) and Polycomb group (PcG) proteins. TrxG proteins activate transcription and are perhaps best known because of the involvement of the TrxG protein MLL in leukaemia. However, in terms of molecular analysis, they have lived in the shadow of their more famous counterparts, the PcG proteins. Recent advances have improved our understanding of TrxG protein function and demonstrated that the heterogeneous group of TrxG proteins is of critical importance in the epigenetic regulation of the cell cycle, senescence, DNA damage and stem cell biology

Spin-orbit-enhanced Wigner localization in quantum dots

We investigate quantum dots with Rashba spin-orbit coupling in the strongly-correlated regime. We show that the presence of the Rashba interaction enhances the Wigner localization in these systems, making it achievable for higher densities than those at which it is observed in Rashba-free quantum dots. Recurring shapes in the pair-correlated densities of the yrast spectrum, which might be associated with rotational and vibrational modes, are also reported.Comment: 5 pages, 4 figure

The high-pressure behavior of CaMoO4

We report a high-pressure study of tetragonal scheelite-type CaMoO4 up to 29 GPa. In order to characterize its high-pressure behavior, we have combined Raman and optical-absorption measurements with density-functional theory calculations. We have found evidence of a pressure-induced phase transition near 15 GPa. Experiments and calculations agree in assigning the high-pressure phase to a monoclinic fergusonite-type structure. The reported results are consistent with previous powder x-ray-diffraction experiments, but are in contradiction with the conclusions obtained from earlier Raman measurements, which support the existence of more than one phase transition in the pressure range covered by our studies. The observed scheelite-fergusonite transition induces significant changes in the electronic band gap and phonon spectrum of CaMoO4. We have determined the pressure evolution of the band gap for the low- and high-pressure phases as well as the frequencies and pressure dependences of the Raman-active and infrared-active modes. In addition, based upon calculations of the phonon dispersion of the scheelite phase, carried out at a pressure higher than the transition pressure, we propose a possible mechanism for the reported phase transition. Furthermore, from the calculations we determined the pressure dependence of the unit-cell parameters and atomic positions of the different phases and their room-temperature equations of state. These results are compared with previous experiments showing a very good agreement. Finally, information on bond compressibility is reported and correlated with the macroscopic compressibility of CaMoO4. The reported results are of interest for the many technological applications of this oxide.Comment: 36 pages, 10 figures, 8 table

Organic matter in forest arrangements within the Crop-Livestock-Forest Integration System in Mato Grosso State.

In Mato Grosso State, the main objectives of this integration are the shading provided to the animals, the improvement in the pastures? fertility, and the availability of wood for use at the property

Soil P, K, and Al contents in a Crop-Livestock-Forest integration system in Mato Grosso State.

The objective of this study was to evaluate the soil P, K, and Al contents in a CLFi system established in Nova Canaã do Norte-MT, Brazil

Past, present and future perspectives of adipose tissue, exercise and renin-angiotensin-aldosterone system interactions

In past decades, adipose tissue was considered as a mere fat deposit and therefore an energy storage. Nowadays, we know that, by secreting endocrine and paracrine factors, it plays a major role in regulating metabolism and homeostasis. Therefore, from the physiological point of view it is considered as an endocrine organ. Adipose tissue is target of insulin action, which promotes the uptake and storage of glucose in the form of fatty acids. In cardiovascular diseases such as high blood pressure, the response to insulin and the metabolism of adipose tissue are altered. It has been demonstrated that the blocking of the renin-angiotensin-aldosterone system (RAAS) is effective in counteracting those alterations. On the other hand, aerobic exercise has been shown to be a useful tool to modify the adipose tissue, alterations observed in cardiovascular diseases. Exercise changes the phenotype of adipose tissue from white to beige with the consequent improvement in the response to insulin at the systemic level. Recently, it has been proposed that the RAAS, through an increase in the hypotensive arm, could mediate the beneficial effects of exercise on adipose tissue, and favor the development of the beige phenotype of this tissue. In this review we will focus on the interaction of adipose tissue, RAAS and aerobic training in a context of arterial hypertension and insulin resistance.En décadas pasadas, el tejido adiposo ha sido considerado como un mero depósito de grasa y como un órgano de almacenamiento de energía. Hoy en día sabemos que, a través de la secreción de factores endócrinos y parácrinos, éste tejido juega un papel importante en la regulación del metabolismo y la homeostasis. Por lo tanto desde el punto de vista fisiológico se considera al tejido adiposo como un órgano endócrino. El tejido adiposo es blanco de acción de la insulina, promoviendo ésta la captación y el almacenamiento de glucosa en forma de ácidos grasos. En enfermedades cardiovasculares como hipertensión arterial la respuesta a insulina y el metabolismo del tejido adiposo se encuentran alterados. Se ha visto que el bloqueo del sistema renina-angiotensina-aldosterona (RAAS) resulta efectivo para contrarrestar estas alteraciones. Por otra parte, el ejercicio aeróbico ha demostrado ser una herramienta útil para modificar las alteraciones metabólicas del tejido adiposo que se observan en individuos con enfermedades cardiovasculares. Estas modificaciones involucran el cambio de fenotipo del tejido adiposo de blanco a beige con la consecuente mejora en la respuesta a la insulina a nivel sistémico. En este último tiempo se ha propuesto que el RAAS, a través de un aumento en la actividad del brazo hipotensor, podría mediar los efectos benéficos del ejercicio sobre el tejido adiposo, favoreciendo el desarrollo del fenotipo beige de este tejido. En esta revisión se abordará la relación entre tejido adiposo, RAAS y entrenamiento aeróbico en un contexto de hipertensión arterial y resistencia a la insulina.Sociedad Argentina de Fisiologí

Colloidal CuFeS2 Nanocrystals: Intermediate Fe d-Band Leads to High Photothermal Conversion Efficiency

We describe the colloidal hot-injection synthesis of phase-pure nanocrystals (NCs) of a highly abundant mineral, chalcopyrite (CuFeS2). Absorption bands centered at around 480 and 950 nm, spanning almost the entire visible and near infrared regions, encompass their optical extinction characteristics. These peaks are ascribable to electronic transitions from the valence band (VB) to the empty intermediate band (IB), located in the fundamental gap and mainly composed of Fe 3d orbitals. Laser-irradiation (at 808 nm) of an aqueous suspension of CuFeS2 NCs exhibited significant heating, with a photothermal conversion efficiency of 49%. Such efficient heating is ascribable to the carrier relaxation within the broad IB band (owing to the indirect VB-IB gap), as corroborated by transient absorption measurements. The intense absorption and high photothermal transduction efficiency (PTE) of these NCs in the so-called biological window (650-900 nm) makes them suitable for photothermal therapy as demonstrated by tumor cell annihilation upon laser irradiation. The otherwise harmless nature of these NCs in dark conditions was confirmed by in vitro toxicity tests on two different cell lines. The presence of the deep Fe levels constituting the IB is the origin of such enhanced PTE, which can be used to design other high performing NC photothermal agents.Comment: 12 pages, Chemistry of Materials, 31-May-201

Voltage-independent SK-channel dysfunction causes neuronal hyperexcitability in the hippocampus of Fmr1 knock-out mice

Neuronal hyperexcitability is one of the major characteristics of fragile X syndrome (FXS), yet the molecular mechanisms of this critical dysfunction remain poorly understood. Here we report a major role of voltage-independent potassium (

Next-to-leading order QCD predictions for the hadronic WHWH+jet production

We calculate the next-to-leading order(NLO) QCD corrections to the $WH^0$ production in association with a jet at hadron colliders. We study the impacts of the complete NLO QCD radiative corrections to the integrated cross sections, the scale dependence of the cross sections, and the differential cross sections ($\frac{d \sigma}{d\cos\theta}$, $\frac{d \sigma}{dp_T}$) of the final $W$-, Higgs-boson and jet. We find that the corrections significantly modify the physical observables, and reduce the scale uncertainty of the LO cross section. Our results show that by applying the inclusive scheme with $p_{T,j}^{cut}=20 GeV$ and taking $m_H=120 GeV$, $\mu=\mu_0\equiv\frac{1}{2}(m_W+m_H)$, the K-factor is 1.15 for the process $p\bar p \to W^{\pm}H^0j+X$ at the Tevatron, while the K-factors for the processes $pp \to W^-H^0j+X$ and $pp \to W^+H^0j+X$ at the LHC are 1.12 and 1.08 respectively. We conclude that to understand the hadronic associated $WH^0$ production, it is necessary to study the NLO QCD corrections to $WH^0j$ production process which is part of the inclusive $WH^0$ production.Comment: 26 pages, 27 figures, accepted by Phys. Rev.

Prediction of Local Structural Stabilities of Proteins from Their Amino Acid Sequences

Hydrogen exchange experiments provide detailed information about the local stability and the solvent accessibility of different regions of the structures of folded proteins, protein complexes, and amyloid fibrils. We introduce an approach to predict protection factors from hydrogen exchange in proteins based on the knowledge of their amino acid sequences without the inclusion of any additional structural information. These results suggest that the propensity of different regions of the structures of globular proteins to undergo local unfolding events can be predicted from their amino acid sequences with an accuracy of 80% or better. © 2007 Elsevier Ltd. All rights reserved