7,375 research outputs found
DNA sequencing and taxonomy of unusual serrate Juniperus from Mexico: Chloroplast capture and incomplete lineage sorting in J. coahuilensis and allied taxa
Analysis of nrDNA, petN-psbM, trnS-trnG, trmD-trnT, and trnF-trnL of Juniperus coahuilensis and allied taxa of Mexico found typical J. coahuilensis, as well as individuals with: coahuilensis cp and hybrid ITS; coahuilensis cp and novel ITS sequence (La Parrilla type); novel Blue Fruited cp (blue fruited taxon) and coahuilensis ITS; plus Blue Fruited cp and La Parrila ITS. nrDNA data was examined and found to detect hybridization, chloroplast capture and incomplete lineage sorting. In addition, a new taxon was found with Blue Fruited (Blue Fruited) cp and J. martinezii ITS, suggestive of chloroplast capture. New records of J. saltillensis were confirmed from Zacatecas. A new record of J. martinezii from Durango was also confirmed. Several plants affiliated with either J. martinezii, or J. flaccida were in distinct clades showing the need for additional research on their volatile leaf oils, morphology and ecology to address their taxonomic status. And lastly, a very unusual population of junipers large, single stemmed trees with aff. J. poblana was found in Nayarit, with long and pendulous foliage. Analysis of the leaf volatile oils, ecology and morphology of this taxon is necessary (in progress) to ascertain its taxonomic rank
DNA sequencing and taxonomy of unusual serrate Juniperus from Mexico: Chloroplast capture and incomplete lineage sorting in J. coahuilensis and allied taxa
Analysis of nrDNA, petN-psbM, trnS-trnG, trmD-trnT, and trnF-trnL of Juniperus coahuilensis and allied taxa of Mexico found typical J. coahuilensis, as well as individuals with: coahuilensis cp and hybrid ITS; coahuilensis cp and novel ITS sequence (La Parrilla type); novel Blue Fruited cp (blue fruited taxon) and coahuilensis ITS; plus Blue Fruited cp and La Parrila ITS. nrDNA data was examined and found to detect hybridization, chloroplast capture and incomplete lineage sorting. In addition, a new taxon was found with Blue Fruited (Blue Fruited) cp and J. martinezii ITS, suggestive of chloroplast capture. New records of J. saltillensis were confirmed from Zacatecas. A new record of J. martinezii from Durango was also confirmed. Several plants affiliated with either J. martinezii, or J. flaccida were in distinct clades showing the need for additional research on their volatile leaf oils, morphology and ecology to address their taxonomic status. And lastly, a very unusual population of junipers large, single stemmed trees with aff. J. poblana was found in Nayarit, with long and pendulous foliage. Analysis of the leaf volatile oils, ecology and morphology of this taxon is necessary (in progress) to ascertain its taxonomic rank
IMMUNOPARALYSIS IN CRITICAL ILL PATIENTS AND ITS ASSOCIATION TO NOSOCOMIAL AND OPPORTUNIST INFECTIONS. A PRELIMINARY STUDY
Proper motions of the HH1 jet
We describe a new method for determining proper motions of extended objects,
and a pipeline developed for the application of this method. We then apply this
method to an analysis of four epochs of [S~II] HST images of the HH~1 jet
(covering a period of ~yr).
We determine the proper motions of the knots along the jet, and make a
reconstruction of the past ejection velocity time-variability (assuming
ballistic knot motions). This reconstruction shows an "acceleration" of the
ejection velocities of the jet knots, with higher velocities at more recent
times. This acceleration will result in an eventual merging of the knots in
~yr and at a distance of from the outflow source, close to
the present-day position of HH~1.Comment: 12 pages, 8 figure
A deep survey of short GRB host galaxies over : implications for offsets, redshifts, and environments
A significant fraction (30\%) of well-localized short gamma-ray bursts
(sGRBs) lack a coincident host galaxy. This leads to two main scenarios:
\textit{i}) that the progenitor system merged outside of the visible light of
its host, or \textit{ii}) that the sGRB resided within a faint and distant
galaxy that was not detected by follow-up observations. Discriminating between
these scenarios has important implications for constraining the formation
channels of neutron star mergers, the rate and environments of gravitational
wave sources, and the production of heavy elements in the Universe. In this
work, we present the results of our observing campaign targeted at 31 sGRBs
that lack a putative host galaxy. Our study effectively doubles the sample of
well-studied sGRB host galaxies, now totaling 72 events of which lack a
coincident host galaxy to deep limits (\,\, or
\,\, AB mag), and represents the largest homogeneously
selected catalog of sGRB offsets to date. We find that 70\% of sub-arcsecond
localized sGRBs occur within 10 kpc of their host's nucleus, with a median
projected physical offset of kpc. Using this larger population, we
discover a redshift evolution in the locations of sGRBs: bursts at low-
occur at larger offsets compared to those at \,\,.
Furthermore, we find evidence for a sample of hostless sGRBs at
\,\, that are indicative of a larger high- population,
further constraining the sGRB redshift distribution and disfavoring log-normal
delay time models.Comment: Submitted to MNRAS. 39 pages, 18 Figures, 4 Table
ALMA Long Baseline Observations of the Strongly Lensed Submillimeter Galaxy HATLAS J090311.6+003906 at z=3.042
We present initial results of very high resolution Atacama Large
Millimeter/submillimeter Array (ALMA) observations of the =3.042
gravitationally lensed galaxy HATLAS J090311.6+003906 (SDP.81). These
observations were carried out using a very extended configuration as part of
Science Verification for the 2014 ALMA Long Baseline Campaign, with baselines
of up to 15 km. We present continuum imaging at 151, 236 and 290 GHz, at
unprecedented angular resolutions as fine as 23 milliarcseconds (mas),
corresponding to an un-magnified spatial scale of ~180 pc at z=3.042. The ALMA
images clearly show two main gravitational arc components of an Einstein ring,
with emission tracing a radius of ~1.5". We also present imaging of CO(10-9),
CO(8-7), CO(5-4) and H2O line emission. The CO emission, at an angular
resolution of ~170 mas, is found to broadly trace the gravitational arc
structures but with differing morphologies between the CO transitions and
compared to the dust continuum. Our detection of H2O line emission, using only
the shortest baselines, provides the most resolved detection to date of thermal
H2O emission in an extragalactic source. The ALMA continuum and spectral line
fluxes are consistent with previous Plateau de Bure Interferometer and
Submillimeter Array observations despite the impressive increase in angular
resolution. Finally, we detect weak unresolved continuum emission from a
position that is spatially coincident with the center of the lens, with a
spectral index that is consistent with emission from the core of the foreground
lensing galaxy.Comment: 9 pages, 5 figures and 3 tables, accepted for publication in the
Astrophysical Journal Letter
IMPACT OF PERSISTENT ENDOTRACHEAL TUBE BIOFILM ON VENTILATOR-ASSOCIATED PNEUMONIA CLINICAL AND MICROBIOLOGICAL RESPONSE
Transcriptional Shift Identifies a Set of Genes Driving Breast Cancer Chemoresistance
Background
Distant recurrences after antineoplastic treatment remain a serious problem for breast cancer clinical management, which threats patients’ life. Systemic therapy is administered to eradicate cancer cells from the organism, both at the site of the primary tumor and at any other potential location. Despite this intervention, a significant proportion of breast cancer patients relapse even many years after their primary tumor has been successfully treated according to current clinical standards, evidencing the existence of a chemoresistant cell subpopulation originating from the primary tumor.Methods/Findings
To identify key molecules and signaling pathways which drive breast cancer chemoresistance we performed gene expression analysis before and after anthracycline and taxane-based chemotherapy and compared the results between different histopathological response groups (good-, mid- and bad-response), established according to the Miller & Payne grading system. Two cohorts of 33 and 73 breast cancer patients receiving neoadjuvant chemotherapy were recruited for whole-genome expression analysis and validation assay, respectively. Identified genes were subjected to a bioinformatic analysis in order to ascertain the molecular function of the proteins they encode and the signaling in which they participate. High throughput technologies identified 65 gene sequences which were over-expressed in all groups (P ≤ 0·05 Bonferroni test). Notably we found that, after chemotherapy, a significant proportion of these genes were over-expressed in the good responders group, making their tumors indistinguishable from those of the bad responders in their expression profile (P ≤ 0.05 Benjamini-Hochgerg`s method).Conclusions
These data identify a set of key molecular pathways selectively up-regulated in post-chemotherapy cancer cells, which may become appropriate targets for the development of future directed therapies against breast cancer.Thanks are due to the ConsejerÃa de Economia, Innovación y Ciencia (CEIC) from the Junta de AndalucÃa and Fondo Europeo de Desarrollo Regional (FEDER)/Fondo de Cohesión Europeo (FSE) to financial support through the Programa Operativo FEDER/FSE de AndalucÃa 2007-2013 and the research project CTS-5350. The authors also acknowledge financial support by the PN de I+D+i 2006-2009/ISCIII/Ministerio de Sanidad, Servicios Sociales e Igualdad (Spain) and Fondo Europeo de Desarrollo Regional (FEDER) from the European Union, through the research project PI06/90388
First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
We present Atacama Large Millimeter/submillimeter Array (ALMA) observations
from the 2014 Long Baseline Campaign in dust continuum and spectral line
emission from the HL Tau region. The continuum images at wavelengths of 2.9,
1.3, and 0.87 mm have unprecedented angular resolutions of 0.075 arcseconds (10
AU) to 0.025 arcseconds (3.5 AU), revealing an astonishing level of detail in
the circumstellar disk surrounding the young solar analogue HL Tau, with a
pattern of bright and dark rings observed at all wavelengths. By fitting
ellipses to the most distinct rings, we measure precise values for the disk
inclination (46.72pm0.05 degrees) and position angle (+138.02pm0.07 degrees).
We obtain a high-fidelity image of the 1.0 mm spectral index (), which
ranges from in the optically-thick central peak and two
brightest rings, increasing to 2.3-3.0 in the dark rings. The dark rings are
not devoid of emission, we estimate a grain emissivity index of 0.8 for the
innermost dark ring and lower for subsequent dark rings, consistent with some
degree of grain growth and evolution. Additional clues that the rings arise
from planet formation include an increase in their central offsets with radius
and the presence of numerous orbital resonances. At a resolution of 35 AU, we
resolve the molecular component of the disk in HCO+ (1-0) which exhibits a
pattern over LSR velocities from 2-12 km/s consistent with Keplerian motion
around a ~1.3 solar mass star, although complicated by absorption at low
blue-shifted velocities. We also serendipitously detect and resolve the nearby
protostars XZ Tau (A/B) and LkHa358 at 2.9 mm.Comment: 11 pages, 5 figures, 2 tables, accepted for publication in the
Astrophysical Journal Letter
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