2,398 research outputs found
The Brera Multi-scale Wavelet (BMW) ROSAT HRI source catalog. I: the algorithm
We present a new detection algorithm based on the wavelet transform for the
analysis of high energy astronomical images. The wavelet transform, due to its
multi-scale structure, is suited for the optimal detection of point-like as
well as extended sources, regardless of any loss of resolution with the
off-axis angle. Sources are detected as significant enhancements in the wavelet
space, after the subtraction of the non-flat components of the background.
Detection thresholds are computed through Monte Carlo simulations in order to
establish the expected number of spurious sources per field. The source
characterization is performed through a multi-source fitting in the wavelet
space. The procedure is designed to correctly deal with very crowded fields,
allowing for the simultaneous characterization of nearby sources. To obtain a
fast and reliable estimate of the source parameters and related errors, we
apply a novel decimation technique which, taking into account the correlation
properties of the wavelet transform, extracts a subset of almost independent
coefficients. We test the performance of this algorithm on synthetic fields,
analyzing with particular care the characterization of sources in poor
background situations, where the assumption of Gaussian statistics does not
hold. For these cases, where standard wavelet algorithms generally provide
underestimated errors, we infer errors through a procedure which relies on
robust basic statistics. Our algorithm is well suited for the analysis of
images taken with the new generation of X-ray instruments equipped with CCD
technology which will produce images with very low background and/or high
source density.Comment: 8 pages, 6 figures, ApJ in pres
Phytochemistry of Commiphora erythraea: A Review:
Commiphora erythraea (Burseraceae) resin derives from the bark injury of the plant, a small tree native to the Arabian Peninsula. The resin is commonly known as myrrh and it is traditionally used to protect livestock from ticks and to treat diseases related to inflammation. The resin is constituted by a volatile and a non-volatile fraction. The volatile fraction is a source of furanosesquiterpenoids among which furanodienone showed to be the most promising pharmacological active compound. The composition and pharmacological activities of the extracts and the isolated compounds have been reviewed
Precautionary saving and health risk evidence from the Italian households using a time series of cross sections
In this paper we analyse the importance of precautionary saving in Italy. In contrast to previous studies, we focus on two contemporaneous sources of uncertainty, income and health expenditures, to explain the presence of precautionary saving. The major changes occurred in public health care policies from 1985 to 1996 have caused households to pay a larger share of their out-of-the-pocket medical expenditures. These
events have caused households to face both a higher expected mean and a larger variance of health expenditures. Moreover, the economic recession occurred in the early ‘90s and the Maastricht requirements led to general worsening of future expectations of income. We therefore expect consumers to react to this uncertainty by generating precautionary saving. We test this prediction using an Euler equation augmented with the presence of the variance of income and health expenditure shocks. By using a time series of cross sections from the ISTAT household budget survey, we find strong support for
precautionary saving as a response to health uncertainty
Management of Symptomatic Venous Aneurysm
Venous aneurysms (VAs) have been described in quite of all the major veins. They represent uncommon events but often life-threatening because of pulmonary or paradoxical embolism. We describe our twelve patients' series with acute pulmonary emboli due to venous aneurysm thrombosis. Our experience underlines the importance of a multilevel case-by-case approach and the immediate venous lower limbs duplex scan evaluation in pulmonary embolism events. Our data confirm that anticoagulant alone is not effective in preventing pulmonary embolism. We believe that all the VAs of the deep venous system of the extremities should be treated with surgery as well as symptomatic superficial venous aneurysm. A simple excision can significantly improve symptoms and prevent pulmonary embolism
Immunomodulation of fucosyl-lactose and lacto-N-fucopentaose on mononuclear cells from multiple sclerosis and healthy subjects
The 1,2-fucosyl-oligosaccharides, and among these the 2’-fucosyl-lactose (2’-FL) and lacto-N-fucopentaose (LNFP)-I, are quantitatively the most represented
oligosaccharides of human milk. They are also seen to represent an important
immune device to prevent nursing infants from severe infectious diarrhoea.
Recent evidences show that the appearance of 2’-FL and LNFP-I in human colostrums
is synchronised with the macrophage inhibition and that LNFP-III induces
a Th2 response from the mouse peripheral immune system. Since mannosyl-fucosyl
receptors are described on the macrophage surface, all these evidences allow
us to investigate on the possible immune function of human 2’-FL and LNFP-I in
vitro on LPS-activated mononuclear cells (MNC) from 12 patients with multiple
sclerosis (MS) and 20 matched health controls (HC). We found that 2’-FL and
LNFP-I significantly decrease, to a different extent, the MNC proliferation from
both HC and MS patients, in a linear and dose-dependent manner. 2’-FL and LNFPI
also reduce the production of IL-12 and IFN-γ, particularly in MS patients as
compared to HC (p=0.01 and p<0.001, respectively), while increasing that of IL-
10. The overall immunomodulatory effect of 2’-FL and LNFP I here presented may
represent a future therapeutic option for the abnormal immune response found in
some monocyte-mediated diseases
Copy number variations in healthy subjects. Case study: iPSC line CSSi005-A (3544) production from an individual with variation in 15q13.3 chromosome duplicating gene CHRNA7
CHRNA7, encoding the neuronal alpha7 nicotinic acetylcholine receptor (a7nAChR), is highly expressed in the brain, particularly in the hippocampus. It is situated in the 15q13.3 chromosome region, frequently associated with a Copy Number Variation (CNV), which causes its duplication or deletion. The clinical significance of CHRNA7 duplications is unknown so far, but there are several research data suggesting that they may be pathogenic, with reduced penetrance. We have produced an iPS cell line from a single healthy donor's fibroblasts carrying a 15q13.3 CNV, including CHRNA7 in order to study the exact role of this CNV during the neurodevelopment
Effect of vacuum level on milk flow traits in Mediterranean Italian buffalo cow
The aim of this study was to determine the effects of six different working vacuum levels (range from 37 to 52 kPa) on the milk production, milk flow rate and milking times in Mediterranean Italian buffalo. A total of eight hundred and one milk flow curves were recorded at random from all of the four hundred and fifty animals in different parity and stage of lactation over a period of 12 weeks, with electronic milk flow meters (Lactocorder®). The different vacuum levels tested did not affect significantly the individual milk production per milking (on average 4.02±0.06 kg). When diminishing vacuum level, a decrease in average and peak flow rate occurred (P<0.001), as well as an increase in effective milking time between attaching the teat cup and reaching the value of 0.20 kg/min at the end of milking (P<0.001). The vacuum levels of 37 and 40 kPa showed good milkability conditions, at which plateau phase was longer than decline phase and lag time was not affected by vacuum level
Design of a Service for the Management of Heart Failure Patients Using Telemedicine
The tremendous prevalence and mortality of heart failure (HF), along with the social and economic impact of its consequences, make an appropriate disease management utmost important. In this context, telemedicine offers promising possibilities. Current clinical guidelines and technological solutions do not address the problem of monitoring at-risk patients and patients affected by mild HF for prevention purposes. The goal of this work is to design a service based on a telemedicine framework for the management of heart failure patients. The proposed service grounds the monitoring of the patient on a custom multi-sensor array that we designed and developed for the purpose. The description of the processes involved in the service was carried out by means of Process Modelling tools, and in particular through Swim Lane Activity Diagrams. The results look promising for the implementation of the service in a real-life scenario. The main strength of the service resides in a) the use of noninvasive monitoring technologies to include patients with a mild HF or at-risk patients; and b) the integration of hospital and territory services to grant continuity and coherence in the treatment
A Multi-Layered Study on Harmonic Oscillations in Mammalian Genomics and Proteomics
Cellular, organ, and whole animal physiology show temporal variation predominantly featuring 24-h (circadian) periodicity. Time-course mRNA gene expression profiling in mouse liver showed two subsets of genes oscillating at the second (12-h) and third (8-h) harmonic of the prime (24-h) frequency. The aim of our study was to identify specific genomic, proteomic, and functional properties of ultradian and circadian subsets. We found hallmarks of the three oscillating gene subsets, including different (i) functional annotation, (ii) proteomic and electrochemical features, and (iii) transcription factor binding motifs in upstream regions of 8-h and 12-h oscillating genes that seemingly allow the link of the ultradian gene sets to a known circadian network. Our multifaceted bioinformatics analysis of circadian and ultradian genes suggests that the different rhythmicity of gene expression impacts physiological outcomes and may be related to transcriptional, translational and post-translational dynamics, as well as to phylogenetic and evolutionary components
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