ENSAMBLES DE AVES DE LOS BOSQUES ENDEMICOS DE POLYLEPIS PACENSIS EN BOLIVIA

Resumen ∙ Los bosques de Polylepis pacensis son endémicos de Bolivia y se distribuyen en los departamentos de La Paz (inmediaciones al nevado Illimani, Quime e Inquisivi) y Cochabamba (Cotacajes). En este estudio, se evaluó el ensamble de aves en cuatro fragmentos de bosque de P. pacensis ubicados en las faldas del nevado Illimani, La Paz, Bolivia. En estos fragmentos de bosque se observaron 31 especies de aves, incluyendo dos especies endémicas de Bolivia, Colibrí Negrito (Aglaeactis pamela) y Pinchaflor Carbonero (Diglossa carbonaria), y dos especies fuertemente especializadas a bosques de Polylepis, Tijeral de Yánac (Leptasthenura yanacensis) y Conirrostro Gigante (Conirostrum binghami). Los bosques de Polylepis pacensis están altamente amenazados por actividades humanas como quema, extracción de leña y agricultura; las cuales podrían estar causando la deforestación y degradación de este importante hábitat para las aves. Es crucial implementar programas de conservación que incluyan la participación activa de la población local.Abstract ∙ Bird assemblages in endemic Polylepis pacensis woodlands in Bolivia Polylepis pacensis woodlands are endemic to Bolivia, distributed in La Paz (near Illimani, Quime, and Inquisivi) and Cochabamba (Cotacajes) departments. In this study, we evaluated the bird assemblages of four fragments of P. pacensis woodlands located in the foothills of nevado Illimani, La Paz, Bolivia. In these woodlands, we recorded 31 bird species, including two endemic species of Bolivia, Black-hooded Sunbeam (Aglaeactis pamela) and Grey-bellied Flowerpiercer (Diglossa carbonaria), and two species strongly specialized to Polylepis woodlands, Tawny Tit-spinetail (Leptasthenura yanacensis) and Giant Conebill (Conirostrum binghami). Polylepis pacensis woodlands are highly threatened by human activities, such as burning, logging and agriculture; which may be causing of deforestation and degradation of this important habitat for bird species. It is crucial to implement conservation programs involving the active participation of local people

Somatic mTOR mutation in clonally expanded T lymphocytes associated with chronic graft versus host disease

Graft versus host disease (GvHD) is the main complication of allogeneic hematopoietic stem cell transplantation (HSCT). Here we report studies of a patient with chronic GvHD (cGvHD) carrying persistent CD4(+) T cell clonal expansion harboring somatic mTOR, NFKB2, and TLR2 mutations. In the screening cohort (n=134), we detect the mTOR P2229R kinase domain mutation in two additional cGvHD patients, but not in healthy or HSCT patients without cGvHD. Functional analyses of the mTOR mutation indicate a gain-of-function alteration and activation of both mTORC1 and mTORC2 signaling pathways, leading to increased cell proliferation and decreased apoptosis. Single-cell RNA sequencing and real-time impedance measurements support increased cytotoxicity of mutated CD4(+) T cells. High throughput drug-sensitivity testing suggests that mutations induce resistance to mTOR inhibitors, but increase sensitivity for HSP90 inhibitors. Our findings imply that somatic mutations may contribute to aberrant T cell proliferations and persistent immune activation in cGvHD, thereby paving the way for targeted therapies. Chronic graft versus host disease (cGvHD) is a major cause of morbidity and mortality in allogeneic bone marrow transplantation. Here the authors identify a recurrent activating mTOR mutation in expanded donor T-cell clones of 3 cGvHD patients, which suggests somatic mutations may contribute to GvHD pathogenesis and opens avenues to targeted therapies.Peer reviewe

MINERvA neutrino detector response measured with test beam data

The MINERvA collaboration operated a scaled-down replica of the solid scintillator tracking and sampling calorimeter regions of the MINERvA detector in a hadron test beam at the Fermilab Test Beam Facility. This article reports measurements with samples of protons, pions, and electrons from 0.35 to 2.0 GeV/c momentum. The calorimetric response to protons, pions, and electrons are obtained from these data. A measurement of the parameter in Birks' law and an estimate of the tracking efficiency are extracted from the proton sample. Overall the data are well described by a Geant4-based Monte Carlo simulation of the detector and particle interactions with agreements better than 4%, though some features of the data are not precisely modeled. These measurements are used to tune the MINERvA detector simulation and evaluate systematic uncertainties in support of the MINERvA neutrino cross section measurement program.Comment: as accepted by NIM

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum