639 research outputs found
Detection of Beat Cepheids in M33 and Their Use as a Probe of the M33 Metallicity Distribution
Our analysis of the Deep CFHT M33 variability survey database has uncovered 5
Beat Cepheids (BCs) that are pulsating in the fundamental and first overtone
modes. With {\it only} the help of stellar pulsation theory and of
mass--luminosity (M-L) relations, derived from evolutionary tracks, we can
accurately determine the metallicities Z of these stars. The [O/H] metallicity
gradient of -0.16 dex/kpc that is inferred from the M33 galacto-centric
distances of these Cepheids and from their 'pulsation' metallicities is in
excellent agreement with the standard spectroscopic metallicity gradients that
are determined from H II regions, early B supergiant stars and planetary
nebulae. Beat Cepheids can thus provide an additional, independent probe of
galactic metallicity distributions.Comment: 5 pages, 2 fig
Frequency of neurolopsychological deficits after traumatic brain injury
El traumatismo craneoencefálico (TCE) puede conllevar impactantes cambios en la vida cotidiana, que incluyen alteraciones a nivel social, profesional, comunicativo y cognitivo (dificultades atencionales, mnemónicas y ejecutivas). Este estudio tuvo por objeto caracterizar la ocurrencia de déficits neuropsicológicos post-TCE y constatar el impacto ocasionado por el nivel de severidad del trauma en el desempeño cognitivo de los pacientes. Participaron 96 adultos en la muestra total, que fue dividida en dos grupos para evaluar el nivel de severidad del trauma: TCE leve (n=39) y TCE grave (n=77). La gravedad de la lesión se clasificó por medio de la Escala de Coma de Glasgow, por la duración de la pérdida de consciencia, o por la amnesia post-traumática. No había diferencias entre la edad y la escolaridad de los participantes. Para la comparación entre los grupos en cuanto a la distribución de ocurrencia de déficits neuropsicológicos, se utilizó el Chi-cuadrado. Se utilizó una batería de evaluación neuropsicológica flexible conformada por tareas verbales y visoespaciales de habilidades lingüísticas, mnemónicas y ejecutivas. Los grupos no se diferenciaron en cuanto a las variables sociodemográficas. Los pacientes con TCE leve tuvieron mejores puntajes comparados con los de TCE grave (número de errores y categorías completadas del Test de clasificación de tarjetas de Wisconsin- [WCST, por sus siglas en inglés]; errores en la parte B del Test de Hayling; y en la interferencia retro y proactiva del Test de aprendizaje auditivo verbal de Rey [RAVLT, por sus siglas en inglés]. El nivel de severidad del trauma parece mostrar diferencias en los individuos en cuanto al desempeño en memoria episódica de información nueva y en el control de interferencia entre los recuerdos; lo mismo se aplica a las funciones de flexibilidad e inhibición. Estos resultados sugieren que es necesaria una mayor inversión en acciones de políticas públicas, priorizando intervenciones neurocognitivas reeducativas y métodos de prevención de accidentes relacionados con lesiones traumáticas que tengan alta incidencia de secuelas.El traumatismo craneoencefálico (TCE) puede conllevar impactantes cambios en la vida cotidiana, que incluyen alteraciones a nivel social, profesional, comunicativo y cognitivo (dificultades atencionales, mnemónicas y ejecutivas). Este estudio tuvo por objeto caracterizar la ocurrencia de déficits neuropsicológicos post-TCE y constatar el impacto ocasionado por el nivel de severidad del trauma en el desempeño cognitivo de los pacientes. Participaron 96 adultos en la muestra total, que fue dividida en dos grupos para evaluar el nivel de severidad del trauma: TCE leve (n=39) y TCE grave (n=77). La gravedad de la lesión se clasificó por medio de la Escala de Coma de Glasgow, por la duración de la pérdida de consciencia, o por la amnesia post-traumática. No había diferencias entre la edad y la escolaridad de los participantes. Para la comparación entre los grupos en cuanto a la distribución de ocurrencia de déficits neuropsicológicos, se utilizó el Chi-cuadrado. Se utilizó una batería de evaluación neuropsicológica flexible conformada por tareas verbales y visoespaciales de habilidades lingüísticas, mnemónicas y ejecutivas. Los grupos no se diferenciaron en cuanto a las variables sociodemográficas. Los pacientes con TCE leve tuvieron mejores puntajes comparados con los de TCE grave (número de errores y categorías completadas del Test de clasificación de tarjetas de Wisconsin- [WCST, por sus siglas en inglés]; errores en la parte B del Test de Hayling; y en la interferencia retro y proactiva del Test de aprendizaje auditivo verbal de Rey [RAVLT, por sus siglas en inglés]. El nivel de severidad del trauma parece mostrar diferencias en los individuos en cuanto al desempeño en memoria episódica de información nueva y en el control de interferencia entre los recuerdos; lo mismo se aplica a las funciones de flexibilidad e inhibición. Estos resultados sugieren que es necesaria una mayor inversión en acciones de políticas públicas, priorizando intervenciones neurocognitivas reeducativas y métodos de prevención de accidentes relacionados con lesiones traumáticas que tengan alta incidencia de secuelas.Traumatic brain injury (TBI) can lead to significant changes in daily life, as well as in social, labor, communicative, and cognitive domains (attention, memory and executive functions). This study aimed to characterize the occurrence of post-TBI neuropsychological deficits as well as to determine whether there is an impact related to the level of severity of the trauma on the patient's performance. Ninety-six adults participated in the study, who were divided in two groups to assess the trauma's level of severity: mild TBI (n=39) and severe TBI (n=57). This severity was classified by the Glasgow Coma Scale, by the duration of consciousness loss, or by post-traumatic amnesia. There were no differences between the groups regarding variables of age and years of schooling. A Chi- square test was used to do a comparison between the two groups in terms of occurrence of neuropsychological deficits. Verbal, visuospatial, mnemonic, linguistic and executive tests composed a flexible neuropsychological battery. Patients with mild TBI had better scores compared to those with severe TBI (number of errors and in completed categories of the Modified Wisconsin Card Sorting Test (MWCST); errors in Part B of The Hayling Test; and proactive and retroactive interference in the Rey Auditory Verbal Learning Test (RAVLT). The severity of the trauma seems to differentiate individual's performance on episodic memory of new information and in the control of interference between memories; the same is applied to flexibility and inhibition functions. These results suggest the need for more investments in public health policy actions, prioritizing neurocognitive remedial intervention and prevention methods for such condition with high incidence of sequelae
Emission from Hot Dust in the Infrared Spectra of Gamma-ray Bright Blazars
A possible source of -ray photons observed from the jets of blazars
is inverse Compton scattering by relativistic electrons of infrared seed
photons from a hot, dusty torus in the nucleus. We use observations from the
Spitzer Space Telescope to search for signatures of such dust in the infrared
spectra of four -ray bright blazars, the quasars 4C 21.35, CTA102, and
PKS 1510089, and the BL Lacertae object ON231. The spectral energy
distribution (SED) of 4C 21.35 contains a prominent infrared excess indicative
of dust emission. After subtracting a non-thermal component with a power-law
spectrum, we fit a dust model to the residual SED. The model consists of a
blackbody with temperature K, plus a much weaker optically thin
component at K. The total luminosity of the thermal dust emission is
erg s. If the dust lies in an equatorial
torus, the density of IR photons from the torus is sufficient to explain the
-ray flux from 4C 21.35 as long as the scattering occurs within a few
parsecs of the central engine. We also report a tentative detection of dust in
the quasar CTA102, in which the luminosity of the infrared excess is erg s. However, in CTA102 the far-IR spectra are too
noisy to detect the m silicate feature. Upper limits to the luminosity
from thermal emission from dust in PKS 1510-089, and ON231, are,
, and erg s, respectively. These
upper limits do not rule out the possibility of inverse Compton up-scattering
of IR photons to -ray energies in these two sources. The estimated
covering factor of the hot dust in 4C 21.35, 22%, is similar to that of
non-blazar quasars; however, 4C 21.35 is deficient in cooler dust.Comment: 23 Pages, 5 Figures, 2 Tables, 1 Machine Readable Table. Accepted to
Ap
HATS-18 b: An Extreme Short--Period Massive Transiting Planet Spinning Up Its Star
We report the discovery by the HATSouth network of HATS-18 b: a 1.980 +/-
0.077 Mj, 1.337 +0.102 -0.049 Rj planet in a 0.8378 day orbit, around a solar
analog star (mass 1.037 +/- 0.047 Msun, and radius 1.020 +0.057 -0.031 Rsun)
with V=14.067 +/- 0.040 mag. The high planet mass, combined with its short
orbital period, implies strong tidal coupling between the planetary orbit and
the star. In fact, given its inferred age, HATS-18 shows evidence of
significant tidal spin up, which together with WASP-19 (a very similar system)
allows us to constrain the tidal quality factor for Sun-like stars to be in the
range 6.5 <= lg(Q*/k_2) <= 7 even after allowing for extremely pessimistic
model uncertainties. In addition, the HATS-18 system is among the best systems
(and often the best system) for testing a multitude of star--planet
interactions, be they gravitational, magnetic or radiative, as well as planet
formation and migration theories.Comment: Submitted. 12 pages, 9 figures, 5 table
Acute Kidney Injury in ADPKD Patients with Pneumonia
Background. In animal models, polycystic kidneys are susceptible to acute kidney injury (AKI). We examined the occurrence of AKI in a cohort of autosomal dominant polycystic kidney disease (ADPKD) and non-ADPKD patients with acute pneumonia. Design. All ADPKD patients admitted to Mayo Clinic Rochester for pneumonia from January 1990 to April 2010 were examined. Sixty-three patients had lobar infiltration and consolidation on chest X-ray. After excluding patients on dialysis, with organ transplantation, and on chronic immunosuppression, 24 remaining ADPKD patients were enrolled. Twenty-three of the 24 were matched with 92 (1 : 4 ratio) non-ADPKD pneumonia patients based on their baseline eGFR. AKI was defined as serum creatinine elevation
≥0.3 mg/dL. Results. Sixteen of the 23 ADPKD patients (69.6%) and 36 of the 92 (39.1%) non-ADPKD patients developed AKI, P = 0.008. In both groups, those who developed AKI had a lower baseline eGFR (41.1 ± 5.00 versus 58.7 ± 11.8 in ADPKD and 40.2 ± 3.65 versus 51.8 ± 2.24 mL/min/1.73 m2 in the non-ADPKD group), more intensive care unit admissions, and longer hospital stays. AKI was associated with a reduced survival in both groups. Conclusions. Patients with ADPKD admitted for acute pneumonia had more frequent episodes of AKI than non-ADPKD patients with comparable kidney function
Dynamical derivation of Bode's law
In a planetary or satellite system, idealized as n small bodies in initially
coplanar, concentric orbits around a large central body, obeying Newtonian
point-particle mechanics, resonant perturbations will cause dynamical evolution
of the orbital radii except under highly specific mutual relationships, here
derived analytically apparently for the first time. In particular, the most
stable situation is achieved (in this idealized model) only when each planetary
orbit is roughly twice as far from the Sun as the preceding one, as observed
empirically already by Titius (1766) and Bode (1778) and used in both the
discoveries of Uranus (1781) and the Asteroid Belt (1801). ETC.Comment: 27 page
HATNet Field G205: Follow-Up Observations of 28 Transiting-Planet candidates and Confirmation of the Planet HAT-P-8b
We report the identification of 32 transiting-planet candidates in HATNet
field G205. We describe the procedures that we have used to follow up these
candidates with spectroscopic and photometric observations, and we present a
status report on our interpretation of the 28 candidates for which we have
follow-up observations. Eight are eclipsing binaries with orbital solutions
whose periods are consistent with their photometric ephemerides; two of these
spectroscopic orbits are singled-lined and six are double-lined. For one of the
candidates, a nearby but fainter eclipsing binary proved to be the source for
the HATNet light curve, due to blending in the HATNet images. Four of the
candidates were found to be rotating more rapidly than vsini = 50 km/s and were
not pursued further. Thirteen of the candidates showed no significant velocity
variation at the level of 0.5 to 1.0 km/s . Seven of these were eventually
withdrawn as photometric false alarms based on an independent reanalysis using
more sophisticated tools. Of the remaining six, one was put aside because a
close visual companion proved to be a spectroscopic binary, and two were not
followed up because the host stars were judged to be too large. Two of the
remaining candidates are members of a visual binary, one of which was
previously confirmed as the first HATNet transiting planet, HAT-P-1b. In this
paper we confirm that the last of this set of candidates is also a a transiting
planet, which we designate HAT-P-8b, with mass Mp = 1.52 +/- 0.18/0.16 Mjup,
radius Rp = 1.50 +/- 0.08/0.06 Rjup, and photometric period P = 3.076320 +/-
0.000004 days. HAT-P-8b has an inflated radius for its mass, and a large mass
for its period. The host star is a solar-metallicity F dwarf, with mass M* =
1.28 +/- 0.04 Msun and Rp = 1.58 +/- 0.08/0.06 Rsun.Comment: 16 pages, 6 figures, 13 table
Evaluation of Population-Level Changes Associated With the 2021 US Preventive Services Task Force Lung Cancer Screening Recommendations in Community-Based Health Care Systems
Importance: The US Preventive Services Task Force (USPSTF) released updated lung cancer screening recommendations in 2021, lowering the screening age from 55 to 50 years and smoking history from 30 to 20 pack-years. These changes are expected to expand screening access to women and racial and ethnic minority groups.
Objective: To estimate the population-level changes associated with the 2021 USPSTF expansion of lung cancer screening eligibility by sex, race and ethnicity, sociodemographic factors, and comorbidities in 5 community-based health care systems.
Design, Setting, and Participants: This cohort study analyzed data of patients who received care from any of 5 community-based health care systems (which are members of the Population-based Research to Optimize the Screening Process Lung Consortium, a collaboration that conducts research to better understand how to improve the cancer screening processes in community health care settings) from January 1, 2010, through September 30, 2019. Individuals who had complete smoking history and were engaged with the health care system for 12 or more continuous months were included. Those who had never smoked or who had unknown smoking history were excluded.
Exposures: Electronic health record-derived age, sex, race and ethnicity, socioeconomic status (SES), comorbidities, and smoking history.
Main Outcomes and Measures: Differences in the proportion of the newly eligible population by age, sex, race and ethnicity, Charlson Comorbidity Index, chronic obstructive pulmonary disease diagnosis, and SES as well as lung cancer diagnoses under the 2013 recommendations vs the expected cases under the 2021 recommendations were evaluated using χ2 tests.
Results: As of September 2019, there were 341 163 individuals aged 50 to 80 years who currently or previously smoked. Among these, 34 528 had electronic health record data that captured pack-year and quit-date information and were eligible for lung cancer screening according to the 2013 USPSTF recommendations. The 2021 USPSTF recommendations expanded screening eligibility to 18 533 individuals, representing a 53.7% increase. Compared with the 2013 cohort, the newly eligible 2021 population included 5833 individuals (31.5%) aged 50 to 54 years, a larger proportion of women (52.0% [n = 9631]), and more racial or ethnic minority groups. The relative increases in the proportion of newly eligible individuals were 60.6% for Asian, Native Hawaiian, or Pacific Islander; 67.4% for Hispanic; 69.7% for non-Hispanic Black; and 49.0% for non-Hispanic White groups. The relative increase for women was 13.8% higher than for men (61.2% vs 47.4%), and those with a lower comorbidity burden and lower SES had higher relative increases (eg, 68.7% for a Charlson Comorbidity Index score of 0; 61.1% for lowest SES). The 2021 recommendations were associated with an estimated 30% increase in incident lung cancer diagnoses compared with the 2013 recommendations.
Conclusions and Relevance: This cohort study suggests that, in diverse health care systems, adopting the 2021 USPSTF recommendations will increase the number of women, racial and ethnic minority groups, and individuals with lower SES who are eligible for lung cancer screening, thus helping to minimize the barriers to screening access for individuals with high risk for lung cancer
A low density of 0.8 g/cc for the Trojan binary asteroid 617 Patroclus
The Trojan population consists of two swarms of asteroids following the same
orbit as Jupiter and located at the L4 and L5 Lagrange points of the
Jupiter-Sun system (leading and following Jupiter by 60 degrees). The asteroid
617 Patroclus is the only known binary Trojan (Merline et al. 2001). The orbit
of this double system was hitherto unknown. Here we report that the components,
separated by 680 km, move around the system centre of mass, describing roughly
a circular orbit. Using the orbital parameters, combined with thermal
measurements to estimate the size of the components, we derive a very low
density of 0.8 g/cc. The components of Patroclus are therefore very porous or
composed mostly of water ice, suggesting that they could have been formed in
the outer part of the solar system.Comment: 10 pages, 3 figures, 1 tabl
Laparoscopic removal of a large abdominal foreign body granuloma using single incision laparoscopic surgery (SILS) and extraction bag in a cheetah (Acinonyx jubatus)
This case presents a thorn-induced abdominal foreign
body granuloma that was removed with single incision
laparoscopic surgery and an extraction bag. An 11-yearold
female cheetah presented for routine laparoscopic
ovariectomy. Abdominal palpation detected a midabdominal
mass. Differential diagnoses were neoplasia
and foreign body. Laparoscopic exploration of the
peritoneal cavity revealed an omentalised mass, which
was successfully removed with the aid of bipolar
electrocoagulation. Microscopic investigation
intraoperatively and postoperatively confirmed extensive
foreign body-induced granulomatous inflammation. The
foreign body was well encapsulated by fibrous tissue
with no adjacent stricture formation. The patient made a
complete recovery, and this is the first case report of a
thorn-induced abdominal foreign body removed with
minimally invasive surgery in a wild African carnivore.http://vetrecordcasereports.bmj.comhb201
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