8,341 research outputs found
Group-galaxy correlations in redshift space as a probe of the growth of structure
We investigate the use of the cross-correlation between galaxies and galaxy
groups to measure redshift-space distortions (RSD) and thus probe the growth
rate of cosmological structure. This is compared to the classical approach
based on using galaxy auto-correlation. We make use of realistic simulated
galaxy catalogues that have been constructed by populating simulated dark
matter haloes with galaxies through halo occupation prescriptions. We adapt the
classical RSD dispersion model to the case of the group-galaxy
cross-correlation function and estimate the RSD parameter by fitting
both the full anisotropic correlation function and its multipole
moments. In addition, we define a modified version of the latter statistics by
truncating the multipole moments to exclude strongly non-linear distortions at
small transverse scales. We fit these three observable quantities in our set of
simulated galaxy catalogues and estimate statistical and systematic errors on
for the case of galaxy-galaxy, group-group, and group-galaxy
correlation functions. When ignoring off-diagonal elements of the covariance
matrix in the fitting, the truncated multipole moments of the group-galaxy
cross-correlation function provide the most accurate estimate, with systematic
errors below 3% when fitting transverse scales larger than . Including
the full data covariance enlarges statistical errors but keep unchanged the
level of systematic error. Although statistical errors are generally larger for
groups, the use of group-galaxy cross-correlation can potentially allow the
reduction of systematics while using simple linear or dispersion models.Comment: 18 pages, 16 figure
EPR before EPR: a 1930 Einstein-Bohr thought experiment revisited
In 1930 Einstein argued against consistency of the time-energy uncertainty
relation by discussing a thought experiment involving a measurement of mass of
the box which emitted a photon. Bohr seemingly triumphed over Einstein by
arguing that the Einstein's own general theory of relativity saves the
consistency of quantum mechanics. We revisit this thought experiment from a
modern point of view at a level suitable for undergraduate readership and find
that neither Einstein nor Bohr was right. Instead, this thought experiment
should be thought of as an early example of a system demonstrating nonlocal
"EPR" quantum correlations, five years before the famous
Einstein-Podolsky-Rosen paper.Comment: 11 pages, revised, accepted for publication in Eur. J. Phy
Disinvestment in healthcare: An overview of HTA agencies and organizations activities at European level
Background: In an era of a growing economic pressure for all health systems, the interest for "disinvestment" in healthcare increased. In this context, evidence based approaches such as Health Technology Assessment (HTA) are needed both to invest and to disinvest in health technologies. In order to investigate the extent of application of HTA in this field, methodological projects/frameworks, case studies, dissemination initiatives on disinvestment released by HTA agencies and organizations located in Europe were searched. Methods: In July 2015, the websites of HTA agencies and organizations belonging to the European network for HTA (EUnetHTA) and the International Network of Agencies for HTA (INAHTA) were accessed and searched through the use of the term "disinvestment". Retrieved deliverables were considered eligible if they reported methodological projects/frameworks, case studies and dissemination initiatives focused on disinvestment in healthcare. Results: 62 HTA agencies/organizations were accessed and eight methodological projects/frameworks, one case study and one dissemination initiative were found starting from 2007. With respect to methodological projects/frameworks, two were delivered in Austria, one in Italy, two in Spain and three in U.K. As for the case study and the dissemination initiative, both came from U.K. The majority of deliverables were aimed at making an overview of existing disinvestment approaches and at identifying challenges in their introduction. Conclusions: Today, in a healthcare context characterized by resource scarcity and increasing service demand, "disinvestment" from low-value services and reinvestment in high-value ones is a key strategy that may be supported by HTA. The lack of evaluation of technologies in use, in particular at the end of their lifecycle, may be due to the scant availability of frameworks and guidelines for identification and assessment of obsolete technologies that was shown by our work. Although several projects were carried out in different countries, most remain constrained to the field of research. Disinvestment is a relatively new concept in HTA that could pose challenges also from a methodological point of view. To tackle these challenges, it is necessary to construct experiences at international level with the aim to develop new methodological approaches to produce and grow evidence on disinvestment policies and practices
Effect of Xylanase on the Technological Behaviour of Wheat Flours
The objective of this work is to investigate the effect of enzyme xylanase on the technological behaviour of wheat flours, particularly in alveograms and bread making, using two flour qualities and two bread making methods. The enzyme used was xylanase from Bacillus subtilis which is sold for mainly for baking applications. Breads were made applying both the French and the pan bread methods. Experts scored the external and internal characteristics of breads. Increase in enzyme concentration produced a decrease in maximum pressure (P) and tensile strength/extensibility (P/L) but deformation energy (W) remained almost constant in the alveogram. This means that the water released by the hydrolysis of insoluble pentosans has reduced the tenacity of the dough. The higher the enzyme concentration, the lower the dough consistency during kneading. Besides, the greatest improvement of quality was produced when xylanase was added to low quality flour and when the French type bread making method was applied.Fil: Osella, C.. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Instituto de TecnologĂa de Los Alimentos; ArgentinaFil: de la Torre, M. A. G.. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Instituto de TecnologĂa de Los Alimentos; ArgentinaFil: Erben, Melina. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Instituto de TecnologĂa de Los Alimentos; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Santa Fe; ArgentinaFil: Gallardo, A.. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Instituto de TecnologĂa de Los Alimentos; ArgentinaFil: Sanchez, H.. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Instituto de TecnologĂa de Los Alimentos; Argentin
Functional assessment of cancer therapy questionnaire for breast cancer (FACT-B+4): Italian version validation
BACKGROUND:
Improvements in breast cancer diagnosis and treatment led to an increased incidence of survivors' rate. The healthcare system has to face new problems related not only to the treatment of the disease, but also to the management of the quality of life after the diagnosis. The aim of this study was to validate the Italian version of the Functional Assessment of Cancer Therapy - Breast (FACT-B+4) questionnaire and to evaluate its reliability.
METHODS:
The questionnaire was administered twice, with an interval of three days between each administration, to a cohort of women of the Breast Surgical Unit, PoliclincoUmberto I. Cronbach's alpha was used as a measure of the internal consistency of the Italian version.
RESULTS:
The Italian version of the tool was administered to 55 subjects. The Cronbach's alpha for most scores registered values >0.7, both at baseline and at the follow-up analysis, therefore the subscale showed good internal consistency.
CONCLUSIONS:
The Italian version of FACT-B+4 demonstrated acceptable reliability properties in the Breast Unit patients. The use of this questionnaire seemed to be effective and in line with the results derived from the English and Spanishversions. Internal consistency and validity had similar performance results
Imaging and photogrammetry models of Olduvai Gorge (Tanzania) by Unmanned Aerial Vehicles: A high-resolution digital database for research and conservation of Early Stone Age sites
This paper presents the first aerial mapping of Olduvai Gorge (Tanzania) using Unmanned Aerial Vehicles and photogrammetric techniques, to provide a detailed digital cartographic basis for this world-renowned paleoanthropological site. The survey covered an area of 32Â km2 of Olduvai Gorge, and through the use of aerial photos and ground control points from Global Navigation Satellite Systems, an orthomosaic and Digital Surface Model, with a higher than 5Â cm/pixel ground resolution, were produced. The Digital Surface Model was then denoised to calculate a Digital Elevation Model, and a high-resolution imaging model of Olduvai Gorge was generated. A preliminary morphometric characterization using Geographic Information Systems shows the potential of this approach when analysing multiple topographic variables in large areas of paleoanthropological relevance, including production of a new map template for Olduvai Gorge and new data for the investigation of sedimentary and tectonic processes. These results constitute one of the first attempts to obtain high quality imagery from large geographic areas amenable to Early Stone Age research, and introduce new workflows for the creation of Digital Elevation Models. Overall, the digital dataset produced is intended to support archaeological and geological investigation in this area, and provide new monitoring tools for the conservation of cultural heritage
A comparative study of experimental configurations in synchrotron pair distribution function
The identification and quantification of amorphous components and nanocrystalline phases
with very small crystal sizes, smaller than ~3 nm, within samples containing crystalline phases is
very challenging. However, this is important as there are several types of systems that contain these
matrices: building materials, glass-ceramics, some alloys, etc. The total scattering synchrotron pair
distribution function (PDF) can be used to characterize the local atomic order of the nanocrystalline
components and to carry out quantitative analyses in complex mixtures. Although the resolution in
momentum transfer space has been widely discussed, the resolution in the interatomic distance space
has not been discussed to the best of our knowledge. Here, we report synchrotron PDF data collected at
three beamlines in different experimental configurations and X-ray detectors. We not only discuss the
effect of the resolution in Q-space, Qmax ins of the recorded data and Qmax of the processed data, but we
also discuss the resolution in the interatomic distance (real) space. A thorough study of single-phase
crystalline nickel used as standard was carried out. Then, selected cement-related samples including
anhydrous tricalcium and dicalcium silicates, and pastes derived from the hydration of tricalcium
silicate and ye’elimite with bassanite were analyzed.This work is part of the PhD of Mr. Jesus D. Zea-Garcia. This work was supported by Spanish MINECO and FEDER [BIA2017-82391-R research project and I3 [IEDI-2016-0079] program]
Olive Oil Phenolic Compounds’ Activity against Age-Associated Cognitive Decline: Clinical and Experimental Evidence
Epidemiological studies have shown that consuming olive oil rich in phenolic bioactive compounds is associated with a lower risk of neurodegenerative diseases and better cognitive performance in aged populations. Since oxidative stress is a common hallmark of age-related cognitive decline, incorporating exogenous antioxidants could have beneficial effects on brain aging. In this review, we firstly summarize and critically discuss the current preclinical evidence and the potential neuroprotective mechanisms. Existing studies indicate that olive oil phenolic compounds can modulate and counteract oxidative stress and neuroinflammation, two relevant pathways linked to the onset and progression of neurodegenerative processes. Secondly, we summarize the current clinical evidence. In contrast to preclinical studies, there is no direct evidence in humans of the bioactivity of olive oil phenolic compounds. Instead, we have summarized current findings regarding nutritional interventions supplemented with olive oil on cognition. A growing body of research indicates that high consumption of olive oil phenolic compounds is associated with better preservation of cognitive performance, conferring an additional benefit, independent of the dietary pattern. In conclusion, the consumption of olive oil rich in phenolic bioactive compounds has potential neuroprotective effects. Further research is needed to understand the underlying mechanisms and potential clinical applications
Association between work related stress and health related quality of life: the impact of socio-demographic variables. A cross sectional study in a region of central Italy
The aim of this work is investigate relationship between health-related quality of life and work-related stress and the impact of gender, education level, and age on this relationship. A cross-sectional study was conducted among workers of various setting in Rome and Frosinone. Work-related stress was measured with a demand-control questionnaire and health-related functioning by SF (short form)-12 health survey. There were 611 participants. Men reported high mental composite summary (MCS) and physical composite summary (PCS). In multivariate analysis age, gender (p < 0.001) and job demand (0.045) predicted low PCS. Low MCS predicted poor PCS. Job demand and educational level resulted negatively associated with MCS. In an analysis stratified for age, gender, and educational level, gender and age resulted effect modifier for MCS, gender and education level for PCS. In women increase of decision latitude predict (p = 0.001) an increase in MCS; a low job demand predict high MCS in male (p ≤ 0.001). In younger workers, a lower level of job demand predicted high MCS (<0.001). For PCS, gender and education level resulted effect modifier. In women, high decision latitude predicted higher PCS (p = 0.001) and lower level of job demand results in higher PCS (p ≤ 0.001). Higher educational level resulted predictor of low PCS. Management of risk about work-related stress should consider socio-demographic factors
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