5,998 research outputs found
Effects of the network structural properties on its controllability
In a recent paper, it has been suggested that the controllability of a
diffusively coupled complex network, subject to localized feedback loops at
some of its vertices, can be assessed by means of a Master Stability Function
approach, where the network controllability is defined in terms of the spectral
properties of an appropriate Laplacian matrix. Following that approach, a
comparison study is reported here among different network topologies in terms
of their controllability. The effects of heterogeneity in the degree
distribution, as well as of degree correlation and community structure, are
discussed.Comment: Also available online at: http://link.aip.org/link/?CHA/17/03310
mould design for manufacturing of isogrid structures in composite material
Abstract In the transport industry, fuel consumption and emissions can be reduced introducing very light parts. An optimal solution to these problems consists in the construction of isogrid structures made of composite materials, whose manufacturing process is a critical step, since it can induce some damages that cause the rejection of the produced part. The forming technology, the necessary equipment and the process parameters must be carefully chosen, since they strongly affect the part quality. The mould shape has to be carefully designed since the part presents a complex geometry, due to the presence of ribs, that could present a bad compaction. The aim of this work is to introduce and verify through structural tests a design methodology for the manufacturing of isogrid structures made of composite materials. In particular, the mould groove geometry was defined in order to obtain the right compaction degree. Then, different experimental tests were carried out to determine the quality of the produced structures
An allelic variant in the intergenic region between ERAP1 and ERAP2 correlates with an inverse expression of the two genes
The Endoplasmatic Reticulum Aminopeptidases ERAP1 and ERAP2 are implicated in a variety of immune and non-immune functions. Most studies however have focused on their role in shaping the HLA class I peptidome by trimming peptides to the optimal size. Genome Wide Association Studies highlighted non-synonymous polymorphisms in their coding regions as associated with several immune mediated diseases. The two genes lie contiguous and oppositely oriented on the 5q15 chromosomal region. Very little is known about the transcriptional regulation and the quantitative variations of these enzymes. Here, we correlated the level of transcripts and proteins of the two aminopeptidases in B-lymphoblastoid cell lines from 44 donors harbouring allelic variants in the intergenic region between ERAP1 and ERAP2. We found that the presence of a G instead of an A at SNP rs75862629 in the ERAP2 gene promoter strongly influences the expression of the two ERAPs with a down-modulation of ERAP2 coupled with a significant higher expression of ERAP1. We therefore show here for the first time a coordinated quantitative regulation of the two ERAP genes, which can be relevant for the setting of specific therapeutic approaches
Quantum test of the equivalence principle for atoms in superpositions of internal energy eigenstates
The Einstein Equivalence Principle (EEP) has a central role in the
understanding of gravity and space-time. In its weak form, or Weak Equivalence
Principle (WEP), it directly implies equivalence between inertial and
gravitational mass. Verifying this principle in a regime where the relevant
properties of the test body must be described by quantum theory has profound
implications. Here we report on a novel WEP test for atoms. A Bragg atom
interferometer in a gravity gradiometer configuration compares the free fall of
rubidium atoms prepared in two hyperfine states and in their coherent
superposition. The use of the superposition state allows testing genuine
quantum aspects of EEP with no classical analogue, which have remained
completely unexplored so far. In addition, we measure the Eotvos ratio of atoms
in two hyperfine levels with relative uncertainty in the low ,
improving previous results by almost two orders of magnitude.Comment: Accepted for publication in Nature Communicatio
Femicide Fatal Risk Factors: A Last Decade Comparison between Italian Victims of Femicide by Age Groups
Femicide is a wide-spread lethal form of violence against women. Despite its diffusion, to date, very few studies analyzed possible victims' age differences in regard to fatal risk factors for femicide. To this aim, we carried out archive research on Italian femicide cases in the last decade, by comparing prior types of violence suffered and motives for femicide, which are considered crucial fatal risk factors for femicide, across adolescent/young (15-24 years), adults (25-64 years) and older women (65-93 years). From 2010 to 2019 we found 1207 female victims. Characteristics of victims, perpetrators, and their relationship were consistent with those found by international studies and underlined that the majority of femicides were perpetrated by an intimate partner. The results regarding fatal risk factors comparisons across age groups showed the existence of significant differences regarding both types of violence suffered prior to femicide and motives for femicide. The results are discussed in terms of policy implication and intervention
analysis of thermal damage in frp drilling
Abstract Among machining operations applied to polymeric composite materials, drilling is the more important one due to the need to implement mechanical couplings, which in most cases are not yet possible using structural adhesives. Such process is very critical because not only it causes the interruption of the fibers continuity, but also it can generate localized thermal shock in the resin, due to the presence of extremely hard and abrasive fibers and to the low thermal conductivity of the resin itself, that limits the heat dissipation. These phenomena are more severe in dry machining process, that are used in aeronautic industry. The poor FRP machinability is manifested in the induced phenomena of delamination, fragmentation and matrix thermal damage that cause negative outcomes, such as the reduction of the material fatigue strength and the consequent decay of long-term performance. The evaluation of such critical issues is possible through indirect analysis, that is through the analysis of some control parameters, such as the process forces and temperatures that assume different values depending on the combination of cutting parameters. Therefore, to acquire useful information for machining optimization is possible through process monitoring: the input data can be analyzed, processed and made available to optimize the process parameters in order to reduce critical issues such as the delamination, the fragmentation and the thermal damage. The present work deals with the problem of damage due to the high temperatures reached during the FRP dry drilling process. The temperature was measured by K type thermocouples positioned in the workpiece, near the hole surface, and it was evaluated as a function of the main process parameters in order to estimate the critical cutting conditions that lead to critical temperature overcoming
Highly Automated Dipole EStimation (HADES)
Automatic estimation of current dipoles from biomagnetic data is
still a problematic task. This is due not only to the ill-posedness of
the inverse problem but also to two intrinsic difficulties introduced by
the dipolar model: the unknown number of sources and the nonlinear
relationship between the source locations and the data. Recently, we
have developed a new Bayesian approach, particle filtering, based on
dynamical tracking of the dipole constellation. Contrary to many
dipole-based methods, particle filtering does not assume stationarity
of the source configuration: the number of dipoles and their positions
are estimated and updated dynamically during the course of the MEG
sequence. We have now developed a Matlab-based graphical user interface,
which allows nonexpert users to do automatic dipole estimation
from MEG data with particle filtering. In the present paper, we describe
the main features of the software and show the analysis of both
a synthetic data set and an experimental dataset
FILODINAMICA E FILOGEOGRAFIA DEI PRINCIPALI SOTTOTIPI DI HCV NEI BALCANI OCCIDENTALI
ABSTRACT
Hepatitis C virus (HCV) is the leading cause of liver disease and causes both acute and chronic infection. 130-170 million people are chronically infected worldwide. It is characterized by an high degree of genetic heterogeneity due to the lack of proofreading activities of viral RNA polymerase.
HCV is classified into 7 genotypes, which are subdivided into 67 epidemiologically diverse subtypes. The main 7 HCV genotypes vary in their geographical distribution and their level of genetic diversity.
Genotype 1, 2 , 3 e 4 are endemics because circulating for a long time in restricted regions of the world.
While subtype 1a, 1b, 3a, 2a, 2c and 4d are epidemics because they have spread rapidly in the last century through blood, unsafe medical injections and injection drug use.
The aim of this study was to investigate HCV sub/genotype distribution in Montenegro e Albania and estimate the phylodynamics and phylogeography of the most prevalent subtype in order to reconstruct the origin and diffusion of the virus on a local regional scale, using a Bayesian approach.
To this aim, we analyzed the NS5B gene sequences of a total 162 HCV-positive Montenegrin patients and 67 Albanian subjects HCV chronic infected.
The Montenegrin patients are stratified into two populations: intra-venus drug users (IVDUs) and the general population. Our study showed that the prevalent HCV subtype in Montenegrin general population was 1b (45%) followed by 4d (19%), 3a (17%), 1a (16%) and 2a/c (1%). While in the IVDU Montenegrin population, the most prevalent subtype was 3a (47%), followed by 1a (25%), 4d (20%) and 1b (8%). The subtype 3a was common among subjects who used injecting drug (47%), while the subtype 1b was common related with iatrogenic transmission (53.3%). Likewise the 67 Albanian patients was stratified into two populations: intra-venus drug users (IVDUs) and the general population. The main subtype in the general population was 1b (60%) followed by 2a/c (27%), 3a and 1a (4%) while genotype 4 was present in the 4%. In the IVDU Albanian population the prevalent subtype was 3a (67%), followed by 1a (25%) and 4d (8%). In order to estimate the phylodinamics and phylogeography of HCV subtypes, three separate datasets were prepared that include 227 sequence of HCV 1b, 271 of HCV 3a and 106 of HCV 4d.
The phylogeographical analysis of HCV-1b revealed two main clades: clade A included sequence from Montenegro, Albania, Germany, Italy, Greece and Cyprus; clade B included the majority of the Asian isolates (Turkey and Uzbekistan). The origin of the tree root is dated back to the year 1912 in Cyprus (state probability, sp= 0.78). The analysis of population dynamics of entire dataset shows an exponential growth of the 1b epidemics between 1960-1980, after the curve reached a plateau that still continuing.
Phylogeographic analysis of HCV-3a showed that the most probable location of the tree root was Pakistan (sp=0.57). The tree showed many significant clade. Clade A and B comprise Asian and East European isolates (Bulgaria, Azerbaijan, Cyprus, Estonia) (pp=0.86 and 0.98); the clade C included 21 Pakistan isolates (pp=0.88); clade D, E, F and G included Montenegrin isolates. The time of most recent common ancestor (tMRCA) of the tree root went back to about 144 years ago, the clade A and B origin in Azerbaijan about 22 years ago (1992). The four Montenegrin clade dated back between 6-17 year ago corresponding to 1997-2007. The phylodinamics analysis of 54 Montenegrin and Albanian sequence revealed segregation between the two locations. The tree showed many recent Montenegrin clade dating back 10-11 years ago. The skyline plot suggest that subtype 3a was present in the population in the 1980, after occur a biphasic exponential growth between 1980-1990 and mid of XXI century.
Phylogeographic analysis of HCV-4d shows two main significant clade: clade I included Turkish isolates; whereas the clade II included European sequences (Italian, Montenegrin, Albanian, French and Dutch). The Montenegrin isolates segregates in an unique significant clade. The root had a tMRCA of 125 years ago corresponding to 1888; the Turkish clade had a tMRCA of 48 years ago (1966) whereas the European clade had an origin of 65 years ago (1948). The Montenegrin sequences had a tMRCA of 50 years ago dating back 1964.
This study suggests that HCV in Western Balkans present an high heterogeneity regarding subtype distribution through different transmission routes. In particular, HCV-1b penetrated in the XX century in the Aegean area and spread in Europe through two entrance; one in the Eastern Europe and the other in the Eastern Mediterranean probably related to unsafe iatrogenic procedure in the area after the 1950s.
HCV-3a showed an old origin about 144 years ago in Pakistan but a recent increase in Central Asia and Eastern Europe about 20 years ago with rapid spread in Montenegro among IVDUs living in this area.
HCV 4d entered in Europe probably through Italy in 1930 and spread in Western Balkans in the 1960s showing a clear segregation of the infection in Turkey. Nevertheless, further studies an larger group of samples are needed to clarify the phylodynamics of HCV-4d.
In conclusion, the Western Balkans are an area of encounter of various ethnic groups where the virus can be spread and diversified
- …