2,487 research outputs found
Spread of streptococcus pneumoniae serotype 8-ST63 multidrug-resistant recombinant clone, Spain
Since 2004, a total of 131 isolates of Streptococcus pneumoniae multidrug-resistant invasive serotype 8 have been detected in Spain. These isolates showed resistance to erythromycin, clindamycin, tetracycline, and ciprofloxacin. All isolates were obtained from adult patients and shared a common genotype (sequence type [ST]63; penicillin-binding protein 1a [pbp1a], pbp2b, and pbp2x gene profiles; ermB and tetM genes; and a ParC-S79F change). Sixty-eight isolates that required a ciprofloxacin MIC ≥16 μg/mL had additional gyrA gene changes. Serotype 8-ST63 pbp2x sequences were identical with those of antimicrobial drug-susceptible serotype 8-ST53 isolates. Serotype 8-ST63 pbp2b sequences were identical with those of the multidrug-resistant Sweden 15A-ST63 clone. Recombination between the capsular locus and flanking regions of an ST53 isolate (donor) and an ST63 pneumococcus (recipient) generated the novel 15A-ST63 clone. One recombination point was upstream of pbp2x and another was within pbp1a. A serotype 8-ST63 clone was identified as a cause of invasive disease in Spain
Use of sonic tomography to detect and quantify wood decay in living trees.
Premise of the studyField methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes.Methods and resultsLiving trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness.ConclusionsSonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees
Sequía e inundación en la hiperllanura pampeana : una mirada desde el lote al municipio
71-77En la Región Pampeana la lluvia, y su elevada variabilidad, es la principal determinante de la producción agropecuaria (Hall et al., 1992)que motoriza la economía de muchos municipios. En los sistemas de producción pampeanos, en los que el riego es aún una práctica poco común, la escasez de lluvias resiente a la producción y propaga sus efectos en el tiempo y en la comunidad a partir de los daños económicos que genera. En el otro extremo, las lluvias excesivas desencadenan procesos de anegamiento e inundación capaces de generar daños de magnitud similar a los de la sequía. En paisajes extremadamente planos o de 'hiperllanura' (Jobbágy et al., 2008), como son los de la Pampa Deprimida e Interior, el escurrimiento lento y dificultoso lleva a que los excesos hídricos se almacenen localmente, elevando los niveles freáticos e incrementando el área ocupada por agua en las zonas más bajas del paisaje. Las inundaciones resultantes son de avance gradual y sostenido y pueden durar muchos meses, generando pérdidas productivas y daños en la infraestructura de áreas rurales y urbanas. En el Oeste Pampeano y en gran parte de la cuenca del Río Salado las fluctuaciones del nivel de la napa freática están estrechamente conectadas al balance hídrico local y con los cuerpos superficiales de agua (Aragón et al., 2010; Badano, 2010). Los excesos hídricos son almacenados localmente en lagunas o en la napa freática, que lentamente sube de nivel. Las napas cercanas a la superficie aumentan fuertemente el rendimiento de los cultivos, especialmente en años secos (Nosetto et al., 2009), representando una vía de transferencia de agua de años de exceso a años de déficit (Jobbagy et al., 2008). Sin embargo, una vez que la napa supera un umbral de cercanía a la superficie el rendimiento cae abruptamente (Nosetto et al., 2009)y, a nivel de paisaje, el área ocupada por cuerpos de agua se expande con mucha rapidez, las lagunas comienzan a coalecer y en casos extremos se disparan inundaciones regionales (Aragón et al., 2010). Como el drenaje superficial natural y/o artificial de los excedentes tiene un alcance limitado en la región (Badano, 2010), cobra gran importancia el control de la recarga para evitar llegar a ese umbral crítico en el que aumenta el riesgo de inundación. Existen evidencias de que el reemplazo de pasturas perennes por cultivos ha aumentado la recarga (Nosetto et al., 2012), especialmente cuando luego de algunos años secos se siembran campos bajos que luego, en años húmedos, quedan sin sembrar o pierden sus cultivos tempranamente. Al margen del riesgo de inundación, los productores también se beneficiarían si lograran disminuir los excedentes hídricos. Aumentar la transpiración vegetal es una de las avenidas más potentes para lograr mayor productividad del agua limitando otras vías de pérdidas del sistema (Passioura, 2006), como el drenaje profundo o la evaporación desde grandes cuerpos de agua durante una inundación. Por eso, aunque pueden existir conflictos entre distintos usos de la tierra y los intereses de los municipios, también es claro que puede haber oportunidades para un beneficio mutuo. Lograr un uso más inteligente y justo del territorio requiere del conocimiento de los beneficios y riesgos que enfrentan sus múltiples usuarios y las alternativas disponibles. Frente al rol dual del agua en la Hiperllanura Pampeana, es valioso adaptar las estrategias de uso de la tierra para minimizar riesgos y daños maximizando la producción y el desarrollo económico. Para dar este paso surge una necesidad previa que es la de comprender la percepción que distintos actores del territorio tienen respecto a estas fluctuaciones ecohidrológicas. Con ese objetivo, realizamos un taller de discusión en la localidad de América, guiados por las siguientes preguntas: ¿en qué medida difieren los efectos, productivos y económicos, de la sequía y la inundación? ¿Cómo afectan estas perturbaciones aperturbaciones a distintos productores y a todo un municipio? ¿Cuáles son sus opciones y respuestas más comunes? Este trabajo presenta los hallazgos más sobresalientes
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Acromegaly is associated with increased cancer risk: A survey in Italy
It is debated if acromegalic patients have an increased risk to develop malignancies. The aim of the present study was to assess the standardized incidence ratios (SIRs) of different types of cancer in acromegaly on a large series of acromegalic patients managed in the somatostatin analogs era. It was evaluated the incidence of cancer in an Italian nationwide multicenter cohort study of 1512 acromegalic patients, 624 men and 888 women, mean age at diagnosis 45 \uc2\ub1 13 years, followed up for a mean of 10 years (12573 person-years) in respect to the general Italian population. Cancer was diagnosed in 124 patients, 72 women and 52 men. The SIRs for all cancers was significantly increased compared to the general Italian population (expected: 88, SIR 1.41; 95% CI, 1.18-1.68, P < 0.001). In the whole series, we found a significantly increased incidence of colorectal cancer (SIR 1.67; 95% CI, 1.07-2.58, P = 0.022), kidney cancer (SIR 2.87; 95% CI, 1.55-5.34, P < 0.001) and thyroid cancer (SIR 3.99; 95% CI, 2.32-6.87, P < 0.001). The exclusion of 11 cancers occurring before diagnosis of acromegaly (all in women) did not change remarkably the study outcome. In multivariate analysis, the factors significantly associated with an increased risk of malignancy were age and family history of cancer, with a non-significant trend for the estimated duration of acromegaly before diagnosis. In conclusion, we found evidence that acromegaly in Italy is associated with a moderate increase in cancer risk
Dynamics of Transcription Regulation in Human Bone Marrow Myeloid Differentiation to Mature Blood Neutrophils.
Neutrophils are short-lived blood cells that play a critical role in host defense against infections. To better comprehend neutrophil functions and their regulation, we provide a complete epigenetic overview, assessing important functional features of their differentiation stages from bone marrow-residing progenitors to mature circulating cells. Integration of chromatin modifications, methylation, and transcriptome dynamics reveals an enforced regulation of differentiation, for cellular functions such as release of proteases, respiratory burst, cell cycle regulation, and apoptosis. We observe an early establishment of the cytotoxic capability, while the signaling components that activate these antimicrobial mechanisms are transcribed at later stages, outside the bone marrow, thus preventing toxic effects in the bone marrow niche. Altogether, these data reveal how the developmental dynamics of the chromatin landscape orchestrate the daily production of a large number of neutrophils required for innate host defense and provide a comprehensive overview of differentiating human neutrophils
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