174 research outputs found
Diet and Environment Shape Fecal Bacterial Microbiota Composition and Enteric Pathogen Load of Grizzly Bears
Background: Diet and environment impact the composition of mammalian intestinal microbiota; dietary or health disturbances trigger alterations in intestinal microbiota composition and render the host susceptible to enteric pathogens. To date no long term monitoring data exist on the fecal microbiota and pathogen load of carnivores either in natural environments or in captivity. This study investigates fecal microbiota composition and the presence of pathogenic Escherichia coli and toxigenic clostridia in wild and captive grizzly bears (Ursus arctos) and relates these to food resources consumed by bears. Methodology/Principal Findings: Feces were obtained from animals of two wild populations and from two captive animals during an active bear season. Wild animals consumed a diverse diet composed of plant material, animal prey and insects. Captive animals were fed a regular granulated diet with a supplement of fruits and vegetables. Bacterial populations were analyzed using quantitative PCR. Fecal microbiota composition fluctuated in wild and in captive animals. The abundance of Clostridium clusters I and XI, and of C. perfringens correlated to regular diet protein intake. Enteroaggregative E. coli were consistently present in all populations. The C. sordellii phospholipase C was identified in three samples of wild animals and for the first time in Ursids. Conclusion: This is the first longitudinal study monitoring the fecal microbiota of wild carnivores and comparing it to that o
Lower Prevalence of Antibiotic-Resistant Enterococci on U.S. Conventional Poultry Farms that Transitioned to Organic Practices
Background: In U.S. conventional poultry production, antimicrobials are used for therapeutic, prophylactic, and nontherapeutic purposes. Researchers have shown that this can select for antibiotic-resistant commensal and pathogenic bacteria on poultry farms and in poultry-derived products. However, no U.S. studies have investigated on-farm changes in resistance as conventional poultry farms transition to organic practices and cease using antibiotics
Reliability and Reproducibility of a Novel Grading System for Lesions of the Ligamentous-Fossa-Foveolar Complex in Young Patients Undergoing Open Hip Preservation Surgery.
Background
Several classification systems based on arthroscopy have been used to describe lesions of the ligamentum teres (LT) in young active patients undergoing hip-preserving surgery. Inspection of the LT and associated lesions of the adjuvant fovea capitis and acetabular fossa is limited when done arthroscopically but is much more thorough during open surgical hip dislocation. Therefore, we propose a novel grading system based on our findings during surgical dislocation comprising the full spectrum of ligamentous-fossa-foveolar complex (LFFC) lesions.
Purpose
To determine (1) intraobserver reliability and (2) interobserver reproducibility of our new grading system.
Study Design
Cohort study (diagnosis); Level of evidence, 3.
Methods
We performed this validation study on 211 hips (633 images in total) with surgical hip dislocation (2013-2021). We randomly selected 5 images per grade for each LFFC item to achieve an equal representation of all grades (resulting in 75 images). The ligament, fossa, and fovea were subcategorized into normal, inflammation, degeneration, partial, and complete defects. All surgeries were performed in a standardized way by a single surgeon. The femur was disarticulated using a bone hook, the LT was inspected, documented and resected, then the fossa and fovea were documented with the femoral head in full dislocation using a 70° arthroscope. Six observers with different levels of expertise in hip-preserving surgery independently conducted the measurements twice, and intraclass correlation coefficients (ICC) were calculated to determine (1) intraobserver reliability and (2) interobserver reproducibility of the novel grading system.
Results
For intraobserver reliability, excellent ICCs were found in both the junior and the experienced raters for grading the ligament, fossa, fovea, and total LFFC (ICCs ranged from 0.91 to 0.99 for the LFFC score). We found excellent interobserver reproducibility between raters for all items of the LFFC (all interobserver ICCs ≥ 0.76).
Conclusion
Our new grading system for lesions of the LFFC is highly reliable and reproducible. It covers the full spectrum of damage more precisely than arthroscopic classifications do and offers a scientific basis for standardized intraoperative evaluation
Para a noção de transformação curricular
Neste artigo é evidenciada a relação entre currículo e conhecimento, abordando-se o conhecimento escolar na sua seleção, organização e transformação, a partir de uma revisão do conceito de transposição didática e da proposição dos conceitos de transformação curricular e transformação didática. Qualquer debate sobre o currículo exige a dilucidação do conhecimento e uma reflexão sobre os seus diversos significados, sobretudo quando a educação se torna num projeto amplo de questionamento da realidade social. Para além de várias questões colocadas acerca do conhecimento escolar e do modo como a sua organização pode ser realizada, procura-se centrar o debate numa reflexão sobre as fronteiras entre conhecimentos e esclarecer que, sobre essa temática, jamais poderão existir respostas fechadas.This article highlights the link between curriculum and knowledge, the approach
of school knowledge’s selection, organization and transformation is based on a
revision of the concept of didactic transposition and on the proposal of the concepts
of curriculum and didactic transformation. Debates on curriculum demand an
explanation and a reflection on the multiple meanings of knowledge mainly when
education aims to be a broad project to contest social reality. It aims to focus the
discussion on a reflection regarding the borders between knowledges and to show
that in this subject there are never closed answers.Dans cet article est mis en évidence le rapport entre le curriculum et la connaissance,
en abordant la connaissance scolaire dans sa sélection, son organisation et sa
transformation à partir d’une révision du concept de transposition didactique
et de la proposition des concepts de transformation du curriculum et de
transformation didactique. Toute discussion sur le curriculum exige la dilucidation
de la connaissance et une réflexion sur ses plusieurs signifiés, surtout quand
l’éducation devient un projet plus large de mise en question de la réalité sociale.
Au delà des plusieurs questions posées autour de la connaissance scolaire et de la
manière comme son organisation peut être réalisée, on cherche á fixer le débat
dans une réflexion sur les frontières entre connaissances et éclaircir que, sur cette
thématique jamais ne pourront exister des réponses absolues.En este trabajo se pone en evidencia la relación entre el currículum y el
conocimiento, abordándose el conocimiento escolar en su selección, organización
y transformación desde una revisión del concepto de transposición didáctica y de
la proposición de los conceptos de transformación curricular y transformación
didáctica. Cualquier discusión sobre el currículum requiere la aclaración del
conocimiento y una reflexión sobre sus diversos significados, especialmente
cuando la educación se convierte en un proyecto más amplio de cuestionamiento
de la realidad social. Además de varias preguntas sobre el conocimiento escolar y
el modo en el que su organización puede tener lugar, se intenta centrar el debate
en una reflexión sobre las fronteras entre conocimientos y aclarar que en esta
temática jamás podrán existir respuestas cerradas.(undefined
Ultra-Stable Environment Control for the NEID Spectrometer: Design and Performance Demonstration
Two key areas of emphasis in contemporary experimental exoplanet science are
the detailed characterization of transiting terrestrial planets, and the search
for Earth analog planets to be targeted by future imaging missions. Both of
these pursuits are dependent on an order-of-magnitude improvement in the
measurement of stellar radial velocities (RV), setting a requirement on
single-measurement instrumental uncertainty of order 10 cm/s. Achieving such
extraordinary precision on a high-resolution spectrometer requires
thermo-mechanically stabilizing the instrument to unprecedented levels. Here,
we describe the Environment Control System (ECS) of the NEID Spectrometer,
which will be commissioned on the 3.5 m WIYN Telescope at Kitt Peak National
Observatory in 2019, and has a performance specification of on-sky RV precision
< 50 cm/s. Because NEID's optical table and mounts are made from aluminum,
which has a high coefficient of thermal expansion, sub-milliKelvin temperature
control is especially critical. NEID inherits its ECS from that of the
Habitable-zone Planet Finder (HPF), but with modifications for improved
performance and operation near room temperature. Our full-system stability test
shows the NEID system exceeds the already impressive performance of HPF,
maintaining vacuum pressures below Torr and an RMS temperature
stability better than 0.4 mK over 30 days. Our ECS design is fully open-source;
the design of our temperature-controlled vacuum chamber has already been made
public, and here we release the electrical schematics for our custom
Temperature Monitoring and Control (TMC) system.Comment: Accepted for publication in JATI
The NANOGrav Nine-year Data Set:Mass and Geometric Measurements of Binary Millisecond Pulsars
We analyze 24 binary radio pulsars in the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) nine-year data set. We make 14 significant measurements of the Shapiro delay, including new detections in four pulsar-binary systems (PSRs J0613−0200, J2017+0603, J2302+4442, and J2317+1439), and derive estimates of the binary-component masses and orbital inclination for these MSP-binary systems. We find a wide range of binary pulsar masses, with values as low as for PSR J1918−0642 and as high as for PSR J1614−2230 (both 68.3% credibility). We make an improved measurement of the Shapiro timing delay in the PSR J1918−0642 and J2043+1711 systems, measuring the pulsar mass in the latter system to be (68.3% credibility) for the first time. We measure secular variations of one or more orbital elements in many systems, and use these measurements to further constrain our estimates of the pulsar and companion masses whenever possible. In particular, we used the observed Shapiro delay and periastron advance due to relativistic gravity in the PSR J1903+0327 system to derive a pulsar mass of (68.3% credibility). We discuss the implications that our mass measurements have on the overall neutron-star mass distribution, and on the "mass/orbital-period" correlation due to extended mass transfer
Strong Carbon Features and a Red Early Color in the Underluminous Type Ia SN 2022xkq
We present optical, infrared, ultraviolet, and radio observations of SN
2022xkq, an underluminous fast-declining type Ia supernova (SN Ia) in NGC 1784
( Mpc), from to 180 days after explosion. The
high-cadence observations of SN 2022xkq, a photometrically transitional and
spectroscopically 91bg-like SN Ia, cover the first days and weeks following
explosion which are critical to distinguishing between explosion scenarios. The
early light curve of SN 2022xkq has a red early color and exhibits a flux
excess which is more prominent in redder bands; this is the first time such a
feature has been seen in a transitional/91bg-like SN Ia. We also present 92
optical and 19 near-infrared (NIR) spectra, beginning 0.4 days after explosion
in the optical and 2.6 days after explosion in the NIR. SN 2022xkq exhibits a
long-lived C I 1.0693 m feature which persists until 5 days post-maximum.
We also detect C II 6580 in the pre-maximum optical spectra. These
lines are evidence for unburnt carbon that is difficult to reconcile with the
double detonation of a sub-Chandrasekhar mass white dwarf. No existing
explosion model can fully explain the photometric and spectroscopic dataset of
SN 2022xkq, but the considerable breadth of the observations is ideal for
furthering our understanding of the processes which produce faint SNe Ia.Comment: 38 pages, 16 figures, accepted for publication in ApJ, the figure 15
input models and synthetic spectra are now available at
https://zenodo.org/record/837925
MicroRNA Expression Characterizes Oligometastasis(es)
Cancer staging and treatment presumes a division into localized or metastatic disease. We proposed an intermediate state defined by ≤ 5 cumulative metastasis(es), termed oligometastases. In contrast to widespread polymetastases, oligometastatic patients may benefit from metastasis-directed local treatments. However, many patients who initially present with oligometastases progress to polymetastases. Predictors of progression could improve patient selection for metastasis-directed therapy.Here, we identified patterns of microRNA expression of tumor samples from oligometastatic patients treated with high-dose radiotherapy.Patients who failed to develop polymetastases are characterized by unique prioritized features of a microRNA classifier that includes the microRNA-200 family. We created an oligometastatic-polymetastatic xenograft model in which the patient-derived microRNAs discriminated between the two metastatic outcomes. MicroRNA-200c enhancement in an oligometastatic cell line resulted in polymetastatic progression.These results demonstrate a biological basis for oligometastases and a potential for using microRNA expression to identify patients most likely to remain oligometastatic after metastasis-directed treatment
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29
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