808 research outputs found
The History and geography of the Y chromosome SNPs in Europe: an update
The knowledge of the evolution of the human
genome is strictly dependent on the availability
of appropriate genetic markers and their relative
coverage of genetic variation which refine the
phylogenetic reconstruction. While autosomal
markers are particularly valuable for recognizing
correspondence between genetic and geographic
distances, markers on mitochondrial DNA
(mtDNA) or Non Recombining Portion of Y
Chromosome (NRY), because of their unilinear
transmission, can effectively trace diachronical
patterns of the human peopling.
The maximum extent of polymorphism
coverage has already been reached for the very
small mitochondrial genome (about 16,5
Kbp), whereas the first studies based on RFLPs
(Restriction Fragment Length Polymorphisms)
(Cann et al., 1987) and on sequencing of the
hypervariable regions (Vigliant et al., 1991),
were then combined to get higher resolution
(Torroni et al., 1996), and finally the complete
genome sequencing is now routinely performed
(Achilli et al., 2004, Pala et al., 2009), in order
to detect the whole mtDNA variation. A similar
approach cannot be used yet at population level
for the by far larger nuclear genome. However,
advances in genotyping technology have dramatically
enhanced the resolution of the analysis
at genome-wide level, and recent papers significantly
improved the knowledge of the relationships
among European populations, using 300 to
500 K SNPs (Single Nucleotide Polymorphisms)
on microarrays chips (Tian et al., 2008;
Novembre et al., 2008). As to the NRY, most of
the studies before the year 2000 were performed
using Alu insertion (Hammer, 1995) or STRs
(Short Tandem Repeats) (De Knijff et al., 1997;
Pritchard et al., 1999) with the known limitations
due to recurrence and reversion of this kind
of polymorphisms. Using D-HPLC (Denaturing
High Performance Liquid Chromatography)
technology, Underhill and coworkers (1997)
discovered 22 new SNP biallelic markers, rapidly
raising in number to 167 (Underhill et al.,
2000), 242 (YCC, 2002), about 600 (Karafet et
al., 2008), up to more than 725 presently listed
in the Y-DNA SNP Index 2009, (www.isogg.
org), and the knowledge of Y chromosome phylogeny
and of the spread worldwide of human
populations raised proportionally. The next goal
of the research on Y chromosome will be the use
of specific microarrays that can genotype a much
higher number of SNPs than nowadays routinely
performed, and, ultimately, the complete
Y chromosome sequencing. Waiting for future
developments, this short note reports the state of
the art of the phylogenetic (“history”) and phylogeographic
(“geography”) research on Y chromosome
SNP analyses in Europe, updating the
review published in this Journal by Francalacci
& Sanna at the beginning of 2008
The concentration of personal wealth in Italy 1995-2016
We estimate the distribution of wealth in Italy between 1995 and 2016 using a novel source of inheritance tax files, combined with surveys and national accounts. We find that the level of wealth concentration is in line with other European countries; however, its time trend appears more in line with the US, showing a significant increase over the period studied. The country exhibits one of the greatest declines in the wealth share of the bottom 50%. The paper also shows that age plays a marginal role in explaining wealth concentration. Changes in savings, instead, are the predominant force behind the increase in wealth inequality, even at the top. Equity prices also account for a large share of wealth growth above the 99th percentile, whereas changes in house prices play only a minor role. Finally, we document the growing concentration of life-time wealth transfers, and their increasingly favorable tax treatment
The concentration of personal wealth in Italy 1995–2016
Italy is one the countries with the highest wealth-to-income ratio in the developed world, but knowledge about the size distribution of wealth is currently limited. In this paper we estimate the distribution of personal wealth between 1995 and 2016, a period of economic turbulence and structural reforms. For this, we use a novel source on the full records of inheritance tax files, combined with surveys and national accounts. Unlike available statistics from household surveys alone, our estimates point to a sharp inversion of fortunes between the top and the bottom of the wealth distribution since the mid-1990s. Whereas the level of wealth concentration in Italy is in line with other European countries, its time trend appears more in line with the U.S., showing a large increase. Moreover, Italy stands out as one of the countries with the strongest decline in the wealth share of the bottom 50% of the population. A range of alternative series of wealth concentration, including estimates applying no adjustments and imputations, confirm our main findings. The paper also sheds new light on the determinants of wealth inequality trends. First, we show that although average wealth increases with age, dispersion within age groups remains very high; hence age plays a marginal role in explaining wealth concentration. Second, we show that house prices explain little of the change in wealth across the distribution since 1995. Changes in equity prices account for a large share of wealth growth above the 99th percentile. However, all in all, changes in the volume of assets and savings appear to be the predominant force behind the increase in wealth inequality, even at the top. The probability of top earners to climb to the top of the wealth distribution has doubled since the 2000s. Third, we document the growing role of life-time wealth transfers receipts, their increasing concentration at the top, and their increasingly favourable tax treatment for the wealthy
A versatile facility for the calibration of X-ray polarimeters with polarized and unpolarized controlled beams
We devised and built a versatile facility for the calibration of the next
generation X-ray polarimeters with unpolarized and polarized radiation. The
former is produced at 5.9 keV by means of a Fe55 radioactive source or by X-ray
tubes, while the latter is obtained by Bragg diffraction at nearly 45 degrees.
Crystals tuned with the emission lines of X-ray tubes with molybdenum, rhodium,
calcium and titanium anodes are employed for the efficient production of highly
polarized photons at 2.29, 2.69, 3.69 and 4.51 keV respectively. Moreover the
continuum emission is exploited for the production of polarized photons at 1.65
keV and 2.04 keV and at energies corresponding to the higher orders of
diffraction. The photons are collimated by means of interchangeable capillary
plates and diaphragms, allowing a trade-off between collimation and high
fluxes. The direction of the beam is accurately arranged by means of high
precision motorized stages, controlled via computer so that long and automatic
measurements can be done. Selecting the direction of polarization and the
incidence point we can map the response of imaging devices to both polarized
and unpolarized radiation. Changing the inclination of the beam we can study
the systematic effects due to the focusing of grazing incidence optics and the
feasibility of instruments with large field of view.Comment: 12 pages, 11 figure
Assessment of the Feasibility of an Extended Range Helicopter Operational Standard for Offshore Flights
The accident rate of rotorcraft has improved signi1cantly over the years but at a slow pace, and in any case
the number of accidents per 2ight hours is one or two orders of magnitude higher than that of commercial
aircraft, a consideration that could be reasonably related to the inherent higher risk associate with rotorcraft
operations. This represent a strong evidence of the necessity to introduce airworthiness operation
standards also in the rotorcraft community, as an effective mean to improve safety records, borrowing
from the experience done in the commercial air transport community with the introduction of ETOPS. In
this paper, a 1rst proposal of development of a safety standard for helicopter offshore operation is discussed
together with the possible support to this development that could be given by the EU H2020 project
NITROS
Adrenal Ganglioneuroma with Multifocal Retroperitoneal Extension: A Challenging Diagnosis
A ganglioneuroma (GN) is the rarest and most benign of the neuroblastic tumors and originates from neural crest cells wherever sympathetic nervous tissue exists, such as in the retroperitoneum and adrenal gland. The diagnosis can be very challenging, given the rarity and asymptomatic presentation of this neoplasia, and can be achieved only by means of histological evaluation. Although benign, a few cases of metastatic GNs have been reported in the literature. The prognosis, however, seems to be excellent after surgical resection. We describe a rare case of multifocal retroperitoneal GN, diagnosed incidentally in a 46-year-old woman, with para-aortic and adrenal localizations. After intraoperative pathological diagnosis was made, complete excision of all the visible masses was performed. The postoperative period was uneventful and she was recurrence free 3 months after surgery. To our knowledge, this is the first case report of a multifocal retroperitoneal GN. Among the broad differential diagnoses of adrenal incidentalomas, an adrenal location of neuroblastic tumors should not be forgotten
Surname analysis of the Corsican population reveals an agreement with geographical and linguistic structure
The surname is a cultural trait that is extremely useful for historical and linguistic studies and can effectively be used as a genetic marker. In many human populations the surname is inherited in the paternal lineage, and can therefore be considered a marker for the Y chromosome. In this study, surnames were recorded from the white pages of telephone directories in current use in Corsica in 1993. All surnames present in thirteen villages scattered over the whole island and covering the main historical regions were transcribed. Surname variability was found to be higher in coastal villages, and lower in more isolated communities. The isonymy detected among the thirteen villages allowed the calculation of kinship values, visualized in a tree showing two main clusters, one referring to the northern villages and one encompassing the villages of the south. The pattern reflects the administrative division of the island, with the exception of Vico, which belongs to the southern administrative region but is geographically close to the northern villages, and Ghisoni, which belongs to the northern district but is more similar to the village of Bastelica in the southern district. The data presented here show a structure in the surname distribution that is in substantial agreement with the geographical patterns. The kinship values are consistent with a moderated gene flow among villages producing a surname structure according to the geographic features of the territory
Reduced brain UCP2 expression mediated by microRNA-503 contributes to increased stroke susceptibility in the high-salt fed stroke-prone spontaneously hypertensive rat
UCP2 maps nearby the lod score peak of STR1-stroke QTL in the SHRSP rat strain. We explored the potential contribution of UCP2 to the high-salt diet (JD)-dependent increased stroke susceptibility of SHRSP. Male SHRSP, SHRSR, two reciprocal SHRSR/SHRSP-STR1/QTL stroke congenic lines received JD for 4 weeks to detect brain UCP2 gene/protein modulation as compared with regular diet (RD). Brains were also analyzed for NF-κB protein expression, oxidative stress level and UCP2-targeted microRNAs expression level. Next, based on knowledge that fenofibrate and Brassica Oleracea (BO) stimulate UCP2 expression through PPARα activation, we monitored stroke occurrence in SHRSP receiving JD plus fenofibrate versus vehicle, JD plus BO juice versus BO juice plus PPARα inhibitor. Brain UCP2 expression was markedly reduced by JD in SHRSP and in the (SHRsr.SHRsp-(D1Rat134-Mt1pa)) congenic line, whereas NF-κB expression and oxidative stress level increased. The opposite phenomenon was observed in the SHRSR and in the (SHRsp.SHRsr-(D1Rat134-Mt1pa)) reciprocal congenic line. Interestingly, the UCP2-targeted rno-microRNA-503 was significantly upregulated in SHRSP and decreased in SHRSR upon JD, with consistent changes in the two reciprocal congenic lines. Both fenofibrate and BO significantly decreased brain microRNA-503 level, upregulated UCP2 expression and protected SHRSP from stroke occurrence. In vitro overexpression of microRNA-503 in endothelial cells suppressed UCP2 expression and led to a significant increase of cell mortality with decreased cell viability. Brain UCP2 downregulation is a determinant of increased stroke predisposition in high-salt-fed SHRSP. In this context, UCP2 can be modulated by both pharmacological and nutraceutical agents. The microRNA-503 significantly contributes to mediate brain UCP2 downregulation in JD-fed SHRSP
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