147 research outputs found
Updated opacities from the opacity project
Using the code autostructure, extensive calculations of inner-shell atomic data have been made for the chemical elements He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni. The results are used to obtain updated opacities from the Opacity Project (OP). A number of other improvements on earlier work have also been included. Rosseland-mean opacities from the OP are compared with those from OPAL. Differences of 5-10 per cent occur. The OP gives the 'Z-bump', at log(T) 5.2, to be shifted to slightly higher temperatures. The opacities from the OP, as functions of temperature and density, are smoother than those from OPAL. The accuracy of the integrations used to obtain mean opacities can depend on the frequency mesh used. Tests involving variation of the numbers of frequency points show that for typical chemical mixtures the OP integrations are numerically correct to within 0.1 per cent. The accuracy of the interpolations used to obtain mean opacities for any required values of temperature and density depends on the temperature-density meshes used. Extensive tests show that, for all cases of practical interest, the OP interpolations give results correct to better than 1 per cent. Prior to a number of recent investigations which have indicated a need for downward revisions in the solar abundances of oxygen and other elements, there was good agreement between properties of the Sun deduced from helioseismology and from stellar evolution models calculated using OPAL opacities. The revisions destroy that agreement. In a recent paper, Bahcall et al. argue that the agreement would be restored if opacities for the regions of the Sun with 2 × 106T 5 × 106 K (0.7-0.4 R) were larger than those given by OPAL by about 10 per cent. In the region concerned, the present results from the OP do not differ from those of OPAL by more than 2.5 per cent
Clinical applications of contactless photoplethysmography for monitoring in adults: A systematic review and meta-analysis
Contactless photoplethysmography (cPPG) is a method of physiological monitoring. It differs from conventional monitoring methods (e.g., saturation probe) by ensuring no contact with the subject by use of a camera. The majority of research on cPPG is conducted in a laboratory setting or in healthy populations. This review aims to evaluate the current literature on monitoring using cPPG in adults within a clinical setting. Adhering to the Preferred Items for Systematic Reviews and Meta-analysis (PRISMA, 2020) guidelines, OVID, Webofscience, Cochrane library, and clinicaltrials.org were systematically searched by two researchers. Research articles using cPPG for monitoring purposes in adults within a clinical setting were selected. Twelve studies with a total of 654 individuals were included. Heart rate (HR) was the most investigated vital sign (n = 8) followed by respiratory rate ((n = 2), Sp02 (n = 2), and HR variability (n = 2). Four studies were included in a meta-analysis of HR compared to ECG data which demonstrated a mean bias of –0.13 (95% CI, –1.22–0.96). This study demonstrates cPPG can be a useful tool in the remote monitoring of patients and has demonstrated accuracy for HR. However, further research is needed into the clinical applications of this method
Fasciola hepatica induces eosinophil apoptosis in the migratory and biliary stages of infection in sheep
The aim of the present work was to evaluate the number of apoptotic eosinophils in the livers of sheep experimentally infected with Fasciola hepatica during the migratory and biliary stages of infection. Four groups (n = 5) of sheep were used; groups 1–3 were orally infected with 200 metacercariae (mc) and sacrificed at 8 and 28 days post-infection (dpi), and 17 weeks post-infection (wpi), respectively. Group 4 was used as an uninfected control. Apoptosis was detected using immunohistochemistry with a polyclonal antibody against anti-active caspase-3, and transmission electron microscopy (TEM). Eosinophils were identified using the Hansel stain in serial sections for caspase-3, and by ultrastructural features using TEM. At 8 and 28 dpi, numerous caspase-3+ eosinophils were mainly found at the periphery of acute hepatic necrotic foci. The percentage of caspase -3+ apoptotic eosinophils in the periphery of necrotic foci was high (46.1–53.9) at 8 and 28 dpi, respectively, and decreased in granulomas found at 28 dpi (6%). Transmission electron microscopy confirmed the presence of apoptotic eosinophils in hepatic lesions at 8 and 28 dpi. At 17 wpi, apoptotic eosinophils were detected in the infiltrate surrounding some enlarged bile ducts containing adult flukes. This is the first report of apoptosis induced by F. hepatica in sheep and the first study reporting apoptosis in eosinophils in hepatic inflammatory infiltrates in vivo. The high number of apoptotic eosinophils in acute necrotic tracts during the migratory and biliary stages of infection suggests that eosinophil apoptosis may play a role in F. hepatica survival during different stages of infection
Modeling of Photoionized Plasmas
In this paper I review the motivation and current status of modeling of
plasmas exposed to strong radiation fields, as it applies to the study of
cosmic X-ray sources. This includes some of the astrophysical issues which can
be addressed, the ingredients for the models, the current computational tools,
the limitations imposed by currently available atomic data, and the validity of
some of the standard assumptions. I will also discuss ideas for the future:
challenges associated with future missions, opportunities presented by improved
computers, and goals for atomic data collection.Comment: 17 pages, 8 figures, to appear in the proceedings of Xray2010,
Utrecht, the Netherlands, March 15-17 201
Morphological, molecular and phylogenetic analyses of the spirurid nematode Stegophorus macronectes (Johnston & Mawson, 1942)
©2015. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Accepted, version of a Published Work that appeared in final form in Journal of Helminthology. To access the final edited and published work see https://doi.org/10.1017/S0022149X15000218Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed
Apoptosis of peritoneal leucocytes during early stages of Fasciola hepatica infections in sheep
Several immunomodulatory properties have been described in Fasciola hepatica infections. Apoptosis has been shown to be an effective mechanism to avoid the immune response in helminth infections. The aim of the present work was to study apoptosis in peritoneal leucocytes of sheep experimentally infected with F. hepatica during the early stages of infection. Five groups (n = 5) of sheep were used. Groups 2–5 were orally infected with 200 metacercariae (mc) and sacrificed at 1, 3, 9 and 18 days post-infection (dpi), respectively. Group 1 was used as the uninfected control (UC). Apoptosis was detected using three different methods 1) immunocytochemistry (ICC) with a polyclonal antibody anti-active caspase-3; 2) an annexin V flow cytometry assay using the Annexin V-FITC/propidium iodide (PI); and 3) transmission electron microscopy (TEM). The differential leucocyte count revealed that the majority of peritoneal granulocytes were eosinophils, which increased significantly at 9 and 18 dpi with respect to the uninfected controls. The ICC study revealed that the percentage of caspase-3+ apoptotic peritoneal leucocytes increased significantly from 3 dpi onwards with respect to the uninfected controls. The flow cytometry annexin V assay detected a very significant (P < 0.001) increase of apoptotic peritoneal macrophages, lymphocytes and granulocytes, which remained higher than in the UC until 18 dpi. Transmission electron microscopy studies also confirmed the presence of apoptosis in peritoneal eosinophils at 18 dpi. This is the first report of apoptosis induced by F. hepatica in the peritoneal leucocytes of sheep in vivo. The results of this work suggest the importance of apoptosis induction for the survival of the juvenile parasites in the peritoneal migratory stages of infection
Effets anatomiques de l'ozone sur le térébinthe (Pistacia terebinthus)
Cet article, écrit par des chercheurs espagnols de Valence, décrit les changements anatomiques produits sur les feuilles de térébinthe, arbuste méditerranéen, soumises à différents niveaux d'exposition à l'ozone. On note une grande variabilité de réactions en fonction du stade de développement. Ainsi, des expositions à l'ozone effectuées sur différentes années peuvent produire des lésions visibles, pour des doses d'ozone très différentes
Maternal fish consumption, fatty acid levels and angiogenic factors: The Generation R Study
Introduction Angiogenic factors, such as placental growth factor (PlGF) and soluble Flt-1 (sFlt-1), are key regulators of placental vascular development. Evidence from in vitro studies indicates that fatty acids can affect angiogenesis. We investigated the associations of maternal fish consumption and fatty acids levels with angiogenic factors during pregnancy, and in cord blood in a large population-based prospective cohort. Methods First trimester fish consumption was assessed among 3134 pregnant women using a food-frequency questionnaire. Plasma fatty acid levels were measured in second trimester. Plasma PlGF and sFlt-1 were measured in first and second trimester and in cord blood. Associations of fish consumption or fatty acid levels with angiogenic factors were assessed by multivariable linear regression analyses. Results There were no consistent associations of total fish or lean fish consumption with levels of PlGF, sFlt-1, or sFlt-1/PlGF ratio. Neither fatty fish nor shellfish were associated with angiogenic factors. Plasma omega-3 polyunsaturated fatty acids, which are the main type of fatty acids in fish, were inconsistently associated with angiogenic factors in second trimester and cord blood. Yet, higher levels of arachidonic acid, an omega-6 polyunsaturated fatty acid, were associated with lower levels of PlGF and sFlt-1. Discussion We found no consistent associations of fish consumption or fatty acids levels with angiogenic factors in a population with low fish consumption. Studies including populations with higher fish consumption are required to fully grasp the potential effects of maternal fish consumption on placental angiogenesis
Analisis de las respuestas moleculares profundas alcanzadas por las multiples secuencias de tratamientos con ITKS en LMC. Estudio de largo seguimiento del registro español de LMC
Poster [PC-231]
Introducción: Cinco inhibidores de tirosina cinasa (ITKs) están disponibles para el tratamiento de pacientes con leucemia mieloide crónica en fase crónica (LMC-FC). Analizamos las diferentes secuencias de ITKs utilizadas como terapia para la LMC-FC en un análisis a largo plazo en vida real.
Métodos: En un análisis retrospectivo de cohortes, se incluyeron pacientes con LMC-FC tratados en la práctica clínica con diferentes ITKs en el Registro Español de LMC (RELMC) (17 hospitales de todo el país) entre 2000 y 2014. El objetivo principal del estudio fue describir la secuencia del tratamiento con ITKs en la práctica de la vida real y la última respuesta molecular profunda (DMR) (MR4, MR4.5 o transcrito indetectable) para cada esquema.
Resultados: Nuestro análisis incluyó 862 pacientes con LMC en 1º FC tratados con ITKs en 1ª línea o después de interferón alfa. Datos demográficos demográficos: 517 H, 345 M, mediana de edad: 52 años (14-94a). Distribución del Índice Sokal (bajo 49% Inter 38% Alto 13%), Índice EURO (bajo 50% Inter 45% Alto 5%), Índice EUTOS (bajo 93% Alto 7%), Índice LT-EUTOS (bajo 68 % Inter 25% Alto 7%). Esquemas de tratamiento: la Tabla 1 resume todos los esquemas utilizados y la última respuesta molecular. Los pacientes se dividieron en 4 grupos según el tratamiento con ITKs. Grupo 1: solo tratados con Imatinib 394 p (45, 7%) Grupo 2: Imatinib y luego 2ºGITKs debido a intolerancia o fallo 170 p (19, 7%) (12 esquemas de tratamiento secuenciales diferentes con ITKs) Grupo 3: 2ºGITKs en 1ª línea 91 p (13 esquemas secuenciales) (10, 5%) Grupo 4: Interferón alfa y luego ITKs 207 p (24%) (9 esquemas secuenciales). La Figura 1 resume la evolución de diferentes tratamientos alrededor de los 14 años. Última respuesta molecular profunda: con una mediana de seguimiento de 82 meses (1-351 m) desde el diagnóstico, 77 m (1-311 m) desde el primer tratamiento y 70 m (1-191 m) desde el primer tratamiento con ITK. Las tasas de respuesta molecular profunda para cada grupo fueron (G1: DMR 65% MMR 13% No MMR 15%, G2: DMR 46% MMR 24% No MMR 17%, G3: DMR 62% MMR 13% No MMR 12%, G4: DMR 53% MMR 17% No MMR 18%). Supervivencia a largo plazo (SLP o SG): no se encontraron diferencias estadísticas entre los grupos de tratamiento, ya sea desde el diagnóstico, el primer tratamiento o el primer ITK. Alcanzar una respuesta profunda garantiza mejores resultados. Variables predictivas de respuesta: los índices SOKAL, EUTOS, EURO y LT-EUTOS continúan siendo útiles para predecir el resultado a largo plazo.
Conclusiones: En el contexto de un registro multicéntrico basado en hospitales, el tratamiento con ITKs es muy variable, con un gran número de secuencias diferentes de ITKs. Con una mediana de seguimiento de 7 años la tasa de respuesta molecular profunda es aproximadamente del 60% en pacientes tratados con imatinib y que no necesitan cambio de ITKs, y en aquellos tratados en 1º línea con 2ºGITKs(a pesar de su corto seguimiento), pero parece menor en pacientes tratados con imatinib que necesitan cambiar a 2ºGITKs. Los resultados de supervivencia fueron similares para todos los grupos
Atomic X-ray Spectroscopy of Accreting Black Holes
Current astrophysical research suggests that the most persistently luminous
objects in the Universe are powered by the flow of matter through accretion
disks onto black holes. Accretion disk systems are observed to emit copious
radiation across the electromagnetic spectrum, each energy band providing
access to rather distinct regimes of physical conditions and geometric scale.
X-ray emission probes the innermost regions of the accretion disk, where
relativistic effects prevail. While this has been known for decades, it also
has been acknowledged that inferring physical conditions in the relativistic
regime from the behavior of the X-ray continuum is problematic and not
satisfactorily constraining. With the discovery in the 1990s of iron X-ray
lines bearing signatures of relativistic distortion came the hope that such
emission would more firmly constrain models of disk accretion near black holes,
as well as provide observational criteria by which to test general relativity
in the strong field limit. Here we provide an introduction to this phenomenon.
While the presentation is intended to be primarily tutorial in nature, we aim
also to acquaint the reader with trends in current research. To achieve these
ends, we present the basic applications of general relativity that pertain to
X-ray spectroscopic observations of black hole accretion disk systems, focusing
on the Schwarzschild and Kerr solutions to the Einstein field equations. To
this we add treatments of the fundamental concepts associated with the
theoretical and modeling aspects of accretion disks, as well as relevant topics
from observational and theoretical X-ray spectroscopy.Comment: 63 pages, 21 figures, Einstein Centennial Review Article, Canadian
Journal of Physics, in pres
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