546 research outputs found
Proposal to study transitions
It is proposed to clear some of the puzzles of B decay to the broad
states by studying the corresponding decay with strange
states at LHCb. Interpretation of the results
should be easier due to the narrowness of the state.Comment: 21 page
Disability and its influence in nutritional assessment tools in elderly people living in nursing homes
Introduction: Poor nutritional status is associated with increased morbidity and mortality, especially in older people. Objective: The aim of this study was to assess nutritional status in elderly nursing home residents with different nutritional test, and to determine which parameters used for nutritional assessment can be carried out in this population, which usually have a high prevalence of functionally dependent residents. Methods: A cross-sectional study was performed in 383 elderly. The nutritional assessment tools used were the Mini Nutritional Assessment (MNA), the new ESPEN consensus definition of malnutrition, and the tool for Controlling Nutritional Status (CONUT). Moreover, the ability to perform basic activities of daily living was assessed with the Barthel index (BI). Results: According to BI, 78.9% had a total dependence and only 20.9% could be weighed and heighed. The prevalence of malnutrition with MNA, ESPEN and CONUT was 21.3%, 17.6% and 20.7%, respectively. The agreement between MNA vs ESPEN criteria was moderate (?= 0.483), but with CONUT was low. Conclusions: Nursing homes had a high percentage of totally dependent residents. This high degree of functional dependence made difficult to obtain some anthropometric parameters such as weight and height, which are essential to carry out most nutritional tests. MNA, CONUT and the new ESPEN criteria of malnutrition showed a high prevalence of malnutrition and risk of malnutrition in subjects in which they could be performed.
Introducción: un estado nutricional deficiente está asociado con un incremento de la morbilidad y la mortalidad, especialmente en personas ancianas. Objetivo: el objetivo de este estudio fue evaluar el estado nutricional en ancianos institucionalizados en residencias geriátricas mediante diferentes test nutricionales, y determinar qué parámetros utilizados en la valoración nutricional pueden ser realizados en esta población. Métodos: se llevó a cabo un estudio transversal en 383 ancianos. Las herramientas de valoración nutricional empleadas fueron el Mini Nutritional Assessment (MNA), el nuevo consenso de definición de malnutrición, y el CONUT. Además, la capacidad de realizar las actividades básicas de la vida diaria fue evaluada con el índice de Barthel. Resultados: según el índice de Barthel, hasta un 78, 9% de los residentes tenía una dependencia total, y en solo el 20, 9% se pudo determinar el peso y la talla. La prevalencia de malnutrición con MNA, el consenso de ESPEN y CONUT fueron 21, 3%, 17, 2% y 20, 7%, respectivamente. La concordancia (kappa) entre el MNA y el ESPEN fue moderada (? = 0, 483), pero con CONUT fue baja. Conclusiones: en las residencias geriátricas públicas existe un elevado porcentaje de ancianos totalmente dependientes. Este alto grado de dependencia funcional dificulta la obtención de algunos parámetros antropométricos como el peso y la talla, que son esenciales para llevar a cabo la mayoría de los test de valoración nutricional. El MNA, el CONUT y los nuevos criterios de desnutrición de la ESPEN mostraron una elevada prevalencia de desnutrición y de riesgo de desnutrición en esta población de ancianos institucionalizados, en aquellos en los que fue posible realizarlos
Neck circumference is associated with nutritional status in elderly nursing home residents
Objectives: Anthropometry is an easy and noninvasive method to evaluate nutritional status in institutionalized elderly people who are often bedridden. The aim of this study was to investigate the relationship between the neck circumference (NC) and nutritional status of elderly nursing home residents and to find cutoff points for NC size to identify individuals at risk of malnutrition.
Methods: A cross-sectional study was developed with data collected from 352 elderly people living in five public nursing homes. Different anthropometric measures and the Mini Nutritional Assessment (MNA) were used to determine nutritional status. Receiver operating characteristic (ROC) curves were built for each anthropometric variable to determine their sensitivity and specificity for predicting the risk of malnutrition according to the MNA.
Results: The mean age of the participants (59% females) was 83 years old. In total, 48.3% of women and 45.5% of men were at risk of malnutrition according to their MNA scores. All anthropometric measurements were highly intercorrelated in both men and women, indicating a high degree of collinearity. Bootstrapped linear regression was used to assess the strength of the association between an individuals’ nutritional status and their anthropometric parameters. Calf circumference and NC presented the best predictive value with the highest sensitivity for diagnosing the risk of malnutrition in both institutionalized elderly men and women. The best cutoff points of NC to identify elderly nursing home residents at risk of malnutrition were 35.2 cm for females and 37.8 cm for males.
Conclusions: NC is associated with other classical anthropometric parameters and malnutrition status in elderly people living in nursing homes
Observations of the Hubble Deep Field South with the Infrared Space Observatory - II. Associations and star formation rates
We present results from a deep mid-IR survey of the Hubble Deep Field South
(HDF-S) region performed at 7 and 15um with the CAM instrument on board ISO. We
found reliable optical/near-IR associations for 32 of the 35 sources detected
in this field by Oliver et al. (2002, Paper I): eight of them were identified
as stars, one is definitely an AGN, a second seems likely to be an AGN, too,
while the remaining 22 appear to be normal spiral or starburst galaxies. Using
model spectral energy distributions (SEDs) of similar galaxies, we compare
methods for estimating the star formation rates (SFRs) in these objects,
finding that an estimator based on integrated (3-1000um) IR luminosity
reproduces the model SFRs best. Applying this estimator to model fits to the
SEDs of our 22 spiral and starburst galaxies, we find that they are forming
stars at rates of ~1-100 M_sol/yr, with a median value of ~40M_sol/yr, assuming
an Einstein - de Sitter universe with a Hubble constant of 50 km/s/Mpc, and
star formation taking place according to a Salpeter (1955) IMF across the mass
range 0.1-100M_sol. We split the redshift range 0.0<z<0.6 into two equal-volume
bins to compute raw estimates of the star formation rate density contributed by
these sources, assuming the same cosmology and IMF as above and computing
errors based on estimated uncertainties in the SFRs of individual galaxies. We
compare these results with other estimates of the SFR density made with the
same assumptions, showing them to be consistent with the results of Flores et
al. (1999) from their ISO survey of the CFRS 1415+52 field. However, the
relatively small volume of our survey means that our SFR density estimates
suffer from a large sampling variance, implying that our results, by
themselves, do not place tight constraints on the global mean SFR density.Comment: Accepted for MNRAS. 23 pages, 10 figures (Figs. 4&6 included here as
low resolution JPEGS), latex, uses mn,epsfig. Further information and full
resolution versions of Figs 4&6 available at http://astro.ic.ac.uk/hdfs (v2:
full author list added
Observations of the Hubble Deep Field with the Infrared Space Observatory. I. Data reduction, maps and sky coverage
We present deep imaging at 6.7 micron and 15 micron from the CAM instrument
on the Infrared Space Observatory (ISO), centred on the Hubble Deep Field
(HDF). These are the deepest integrations published to date at these
wavelengths in any region of sky. We discuss the observation strategy and the
data reduction. The observed source density appears to approach the CAM
confusion limit at 15 micron, and fluctuations in the 6.7 micron sky background
may be identifiable with similar spatial fluctuations in the HDF galaxy counts.
ISO appears to be detecting comparable field galaxy populations to the HDF, and
our data yields strong evidence that future IR missions (such as SIRTF, FIRST
and WIRE) as well as SCUBA and millimetre arrays will easily detect field
galaxies out to comparably high redshifts.Comment: 7 pages, LaTeX (using mn.sty), 9 figures included as GIFs. Gzipped
Postscipt version available from http://artemis.ph.ic.ac.uk/hdf/papers/ps/.
Further information on ISO-HDF project can be found at
http://artemis.ph.ic.ac.uk/hdf
Masseter muscle thickness measured by ultrasound as a possible link with sarcopenia, malnutrition and dependence in nursing homes
Sarcopenia is a progressive and generalized loss of skeletal muscle mass and strength. It is frequently associated with malnutrition and dependence in nursing homes. Masticatory muscle strength could be the link between sarcopenia, malnutrition and dependence. We aimed to study the relation between sarcopenia, malnutrition and dependence with masseter muscle thickness measured by ultrasound. A cross-sectional study was realized, with 464 patients from 3 public nursing homes in Zaragoza (Spain). The diagnosis of sarcopenia was assessed according to the EuropeanWorking Group on Sarcopenia in Older People 2 criteria, malnutrition by the Mini Nutritional Assessment (MNA) and the Global Leadership Initiative on Malnutrition (GLIM) criteria and functional capacity by the Barhel Index and the texture diet. Masseter muscle thickness (MMT) was measured by ultrasound. The median age was 84.7 years, and 70% of the participants were women. Sarcopenia was confirmed in 39.2% of patients, malnutrition in 26.5% (risk 47.8%), total dependence in 37.9% and diet texture was modified in 44.6%. By logistic regression, once the model was adjusted for age, sex, Barthel index and texture diet, our analyses indicated that each 1 mm decrease in MMT increased the risk of sarcopenia by ~57% (OR: 0.43), the risk of malnutrition by MNA by ~63% (OR: 0.37) and the risk of malnutrition by GLIM by ~34% (OR: 0.66). We found that MMT was reduced in sarcopenic, malnourished and dependent patients, and it could be the common point of a vicious cycle between sarcopenia and malnutrition. Further studies are needed to establish causality. © 2021 by the authors
The Ncoa7 locus regulates V-ATPase formation and function, neurodevelopment and behaviour
Members of the Tre2/Bub2/Cdc16 (TBC), lysin motif (LysM), domain catalytic (TLDc) protein family are associated with multiple neurodevelopmental disorders, although their exact roles in disease remain unclear. For example, nuclear receptor coactivator 7 (NCOA7) has been associated with autism, although almost nothing is known regarding the mode-of-action of this TLDc protein in the nervous system. Here we investigated the molecular function of NCOA7 in neurons and generated a novel mouse model to determine the consequences of deleting this locus in vivo. We show that NCOA7 interacts with the cytoplasmic domain of the vacuolar (V)-ATPase in the brain and demonstrate that this protein is required for normal assembly and activity of this critical proton pump. Neurons lacking Ncoa7 exhibit altered development alongside defective lysosomal formation and function; accordingly, Ncoa7 deletion animals exhibited abnormal neuronal patterning defects and a reduced expression of lysosomal markers. Furthermore, behavioural assessment revealed anxiety and social defects in mice lacking Ncoa7. In summary, we demonstrate that NCOA7 is an important V-ATPase regulatory protein in the brain, modulating lysosomal function, neuronal connectivity and behaviour; thus our study reveals a molecular mechanism controlling endolysosomal homeostasis that is essential for neurodevelopment
Observations of the Hubble Deep Field with the Infrared Space Observatory V. Spectral energy distributions starburst models and star formation history
We have modelled the spectral energy distributions of the 13 Hubble Deep Field (HDF) galaxies reliably detected by the Infrared Space Observatoiy (ISO). For two galaxies the emission detected by ISO is consistent with being starlight or the infrared 'cirrus' in the galaxies. For the remaining 11 galaxies there is a clear mid-infrared excess, which we interpret as emission from dust associated with a strong starburst. 10 of these galaxies are spirals or interacting pairs, while the remaining one is an elliptical with a prominent nucleus and broad emission lines. We give a new discussion of how the star formation rate can be deduced from the far-infrared luminosity, and derive star formation rates for these galaxies of 8-1000ø M¿ yr-1, where ø takes account of the uncertainty in the initial mass function. The HDF galaxies detected by ISO are clearly forming stars at a prodigious rate compared with nearby normal galaxies. We discuss the implications of our detections for the history of star and heavy element formation in the Universe. Although uncertainties in the calibration, reliability of source detection, associations and starburst models remain, it is clear that dust plays an important role in star formation out to redshift 1 at least
Trust transitivity in social networks
Non-centralized recommendation-based decision making is a central feature of
several social and technological processes, such as market dynamics,
peer-to-peer file-sharing and the web of trust of digital certification. We
investigate the properties of trust propagation on networks, based on a simple
metric of trust transitivity. We investigate analytically the percolation
properties of trust transitivity in random networks with arbitrary degree
distribution, and compare with numerical realizations. We find that the
existence of a non-zero fraction of absolute trust (i.e. entirely confident
trust) is a requirement for the viability of global trust propagation in large
systems: The average pair-wise trust is marked by a discontinuous transition at
a specific fraction of absolute trust, below which it vanishes. Furthermore, we
perform an extensive analysis of the Pretty Good Privacy (PGP) web of trust, in
view of the concepts introduced. We compare different scenarios of trust
distribution: community- and authority-centered. We find that these scenarios
lead to sharply different patterns of trust propagation, due to the segregation
of authority hubs and densely-connected communities. While the
authority-centered scenario is more efficient, and leads to higher average
trust values, it favours weakly-connected "fringe" nodes, which are directly
trusted by authorities. The community-centered scheme, on the other hand,
favours nodes with intermediate degrees, in detriment of the authorities and
its "fringe" peers.Comment: 11 pages, 9 figures (with minor corrections
Effect of magnetically simulated zero-gravity and enhanced gravity on the walk of the common fruitfly†
Understanding the effects of gravity on biological organisms is vital to the success of future space missions. Previous studies in Earth orbit have shown that the common fruitfly (Drosophila melanogaster) walks more quickly and more frequently in microgravity, compared with its motion on Earth. However, flight preparation procedures and forces endured on launch made it difficult to implement on the Earth's surface a control that exposed flies to the same sequence of major physical and environmental changes. To address the uncertainties concerning these behavioural anomalies, we have studied the walking paths of D. melanogaster in a pseudo-weightless environment (0g*) in our Earth-based laboratory. We used a strong magnetic field, produced by a superconducting solenoid, to induce a diamagnetic force on the flies that balanced the force of gravity. Simultaneously, two other groups of flies were exposed to a pseudo-hypergravity environment (2g*) and a normal gravity environment (1g*) within the spatially varying field. The flies had a larger mean speed in 0g* than in 1g*, and smaller in 2g*. The mean square distance travelled by the flies grew more rapidly with time in 0g* than in 1g*, and slower in 2g*. We observed no other clear effects of the magnetic field, up to 16.5 T, on the walks of the flies. We compare the effect of diamagnetically simulated weightlessness with that of weightlessness in an orbiting spacecraft, and identify the cause of the anomalous behaviour as the altered effective gravity
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