5,390 research outputs found
Fast UPLC/PDA determination of squalene in Sicilian P.D.O. pistachio from Bronte: optimization of oil extraction method and analytical characterization
A fast reversed-phase UPLC method was developed for squalene determination in Sicilian pistachio samples that entry in the European register of the products with P.D.O. In the present study the SPE procedure was optimized for the squalene extraction prior to the UPLC/PDA analysis. The precision of the full analytical procedure was satisfactory and the mean recoveries were 92.8 ± 0.3 % and 96.6 ± 0.1 % for 25 and 50 mg L-1 level of addition, respectively. Selected chromatographic conditions allowed a very fast squalene determination; in fact it was well separated in ∼ 0.54 min with good resolution. Squalene was detected in all the pistachio samples analyzed and the levels ranged from 55.45 to 226.34 mg . kg-1. Comparing our results with those of other studies it emerges that squalene contents in P.D.O. Sicilian pistachio samples, generally, were higher than those measured for other samples of different geographic origins
Heidegger and Lacan
Lacanian psychoanalysis cannot disregard its debts to philosophy, especially continental philosophy. Lacan’s conception of language is derived from multiple philosophical sources (i.e., Plato, Aristotle, Kant, Hegel, Kierkegaard) including Heidegger’s philosophy of language and pride of place. Heidegger’s view of language prepares the ground for reversing the relationship between language and human beings, overcoming common sense about language and the communicative model of language. Language is much more than a set of labels; it shapes the human world and structures social relations themselves. In addition, language acts as a social link. The function of language as a social link allows us to think of it in relation to the Law and the very function of this human subjectivity. In reference to the Other of the Law and language, the subject finds her recognition, and this implies that the language is not reducible to communication. The process of technical-scientific domination of Western institutions leads to a reduction of their functions to the formal aspects, which may lead to a reification of the human as well as a state of alienation
Optical counterparts of undetermined type -ray Active Galactic Nuclei with blazar-like Spectral Energy Distributions
During its first four years of scientific observations, the Fermi Large Area
Telescope (Fermi-LAT) detected 3033 -ray sources above a 4
significance level. Although most of the extra-Galactic sources are active
galactic nuclei (AGN) of the blazar class, other families of AGNs are observed
too, while a still high fraction of detections () remains with
uncertain association or classification. According to the currently accepted
interpretation, the AGN -ray emission arises from inverse Compton (IC)
scattering of low energy photons by relativistic particles confined in a jet
that, in the case of blazars, is oriented very close to our line of sight.
Taking advantage of data from radio and X-ray wavelengths, which we expect to
be produced together with -rays, providing a much better source
localization potential, we focused our attention on a sample of -ray
Blazar Candidates of Undetermined Type (BCUs), starting a campaign of optical
spectroscopic observations. The main aims of our investigation include a census
of the AGN families that contribute to -ray emission and a study of
their redshift distribution, with the subsequent implications on the intrinsic
source power. We furthermore analyze which -ray properties can better
constrain the nature of the source, thus helping in the study of objects not
yet associated with a reliable low frequency counterpart. In this communication
we report on the instruments and techniques used to identify the optical
counterparts of -ray sources, we give an overview on the status of our
work, and we discuss the implications of a large scale study of -ray
emitting AGNs.Comment: 9 pages, 2 figures, proceedings of the 10th Serbian Conference on
Spectral Line Shapes in Astrophysics. JOAA, accepte
Relativistic plasmas in AGN jets - From synchrotron radiation to -ray emission
Relativistic jets of plasma are a key ingredient of many types of Active
Galactic Nuclei (AGN). Today we know that AGNs are powered by the accretion of
inter stellar material into the gravitational field of a Super Massive Black
Hole and that this process can release as much power as a whole galaxy, like
the Milky Way, from a region that is comparable to the Solar System in size.
Depending on the properties of the central energy source, a large fraction of
this power can be involved in the acceleration of magnetized plasmas at
relativistic speeds, to form large scale jets. The presence of jets affects the
spectrum of AGNs through the emission of synchrotron radiation and Inverse
Compton scattering of low energy photons, thus leading to a prominent
non-thermal spectrum, some times extending from radio frequencies all the way
up to -ray energies. Here we review some characteristic processes of
radiation emission in AGN jets, which lead to the emission of photons in the
radio, optical, X-ray and -ray bands, and we present the results of a
spectroscopic campaign of optical counterparts. We discuss our observations and
their connection with -ray properties in a scenario that traces the
role of relativistic jets in different classes of AGNs, detected both in the
local as well as in the remote Universe.Comment: 11 pages, 5 figures (3 in color), proceedings of the XXVIII School on
Physics of Ionized Gases (SPIG), accepted for publication on the European
Journal of Physics
How Much Does AMH Really Vary in Normal Women?
Anti-Mullerian Hormone (AMH) is an ovarian hormone expressed in growing follicles that have undergone recruitment from the primordial follicle pool but have not yet been selected for dominance. It is considered an accurate marker of ovarian reserve, able to reflect the size of the ovarian follicular pool of a woman of reproductive age. In comparison to other hormonal biomarkers such as serum FSH, low intra- and intermenstrual cycle variability have been proposed for AMH. This review summarizes the knowledge regarding within-subject variability, with particular attention on AMH intracycle variability. Moreover the impact of ethnicity, body mass index, and smoking behaviour on AMH interindividual variability will be reviewed. Finally changes in AMH serum levels in two conditions of ovarian quiescence, namely contraceptives use and pregnancy, will be discussed. The present review aims at guiding researchers and clinicians in interpreting AMH values and fluctuations in various research and clinical scenarios
A new freeware raycasting tool combined with fluorescent coating to allow for object visibility
Abstract
Time resolved PIV encompassing moving and/or deformable objects interfering with the light source requires the employment of dynamic masking (DM). A few DM techniques have been recently developed, mainly in microfluidics and multiphase flows fields. Most of them require ad-hoc design of the experimental setup, and may spoil the accuracy of the resulting PIV analysis. A new DM technique is here presented which envisages, along with a dedicated masking algorithm, the employment of fluorescent coating to allow for accurate tracking of the object. We show results from measurements obtained through a validated PIV setup demonstrating the need to include a DM step even for objects featuring limited displacements. We compare the proposed algorithm with both a no-masking and a static masking solution. In the framework of developing low cost, flexible and accurate PIV setups, the proposed algorithm is made available through a freeware application able to generate masks to be used by an existing, freeware PIV analysis package.
Graphic abstrac
Loss of brain inter-frequency hubs in Alzheimer's disease
Alzheimer's disease (AD) causes alterations of brain network structure and
function. The latter consists of connectivity changes between oscillatory
processes at different frequency channels. We proposed a multi-layer network
approach to analyze multiple-frequency brain networks inferred from
magnetoencephalographic recordings during resting-states in AD subjects and
age-matched controls. Main results showed that brain networks tend to
facilitate information propagation across different frequencies, as measured by
the multi-participation coefficient (MPC). However, regional connectivity in AD
subjects was abnormally distributed across frequency bands as compared to
controls, causing significant decreases of MPC. This effect was mainly
localized in association areas and in the cingulate cortex, which acted, in the
healthy group, as a true inter-frequency hub. MPC values significantly
correlated with memory impairment of AD subjects, as measured by the total
recall score. Most predictive regions belonged to components of the
default-mode network that are typically affected by atrophy, metabolism
disruption and amyloid-beta deposition. We evaluated the diagnostic power of
the MPC and we showed that it led to increased classification accuracy (78.39%)
and sensitivity (91.11%). These findings shed new light on the brain functional
alterations underlying AD and provide analytical tools for identifying
multi-frequency neural mechanisms of brain diseases.Comment: 27 pages, 6 figures, 3 tables, 3 supplementary figure
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