2,498 research outputs found
Gender in endocrine diseases: role of sex gonadal hormones
Gender- and sex- related differences represent a new frontier towards patient-tailored medicine, taking into account that
theoretically every medical specialty can be influenced by both of them. Sex hormones define the differences between
males and females, and the different endocrine environment promoted by estrogens, progesterone, testosterone, and their
precursors might influence both human physiology and pathophysiology. With the term Gender we refer, instead, to behaviors,
roles, expectations, and activities carried out by the individual in society. In other words, “gender” refers to a sociocultural
sphere of the individual, whereas “sex” only defines the biological sex. In the last decade, increasing attention has been paid to
understand the influence that gender can have on both the human physiology and pathogenesis of diseases. Even the clinical
response to therapy may be influenced by sex hormones and gender, but further research is needed to investigate and clarify
how they can affect the human pathophysiology. The path to a tailored medicine in which every patient is able to receive early
diagnosis, risk assessments, and optimal treatments cannot exclude the importance of gender. In this review, we have focused
our attention on the involvement of sex hormones and gender on different endocrine diseases
Gauge and Averaging in Gravitational Self-force
A difficulty with previous treatments of the gravitational self-force is that
an explicit formula for the force is available only in a particular gauge
(Lorenz gauge), where the force in other gauges must be found through a
transformation law once the Lorenz gauge force is known. For a class of gauges
satisfying a ``parity condition'' ensuring that the Hamiltonian center of mass
of the particle is well-defined, I show that the gravitational self-force is
always given by the angle-average of the bare gravitational force. To derive
this result I replace the computational strategy of previous work with a new
approach, wherein the form of the force is first fixed up to a gauge-invariant
piece by simple manipulations, and then that piece is determined by working in
a gauge designed specifically to simplify the computation. This offers
significant computational savings over the Lorenz gauge, since the Hadamard
expansion is avoided entirely and the metric perturbation takes a very simple
form. I also show that the rest mass of the particle does not evolve due to
first-order self-force effects. Finally, I consider the ``mode sum
regularization'' scheme for computing the self-force in black hole background
spacetimes, and use the angle-average form of the force to show that the same
mode-by-mode subtraction may be performed in all parity-regular gauges. It
appears plausible that suitably modified versions of the Regge-Wheeler and
radiation gauges (convenient to Schwarzschild and Kerr, respectively) are in
this class
Endocrine disrupting chemicals: Effects on endocrine glands
In recent years, endocrine disrupting chemicals have gained interest in human physiopathology and more and more studies aimed to explain how these chemicals compounds affect endocrine system. In human populations, the majority of the studies point toward an association between exposure to endocrine disrupting chemicals and the disorders affecting endocrine axis. A great number of endocrine disrupting chemicals seem to be able to interfere with the physiology of hypothalamus-pituitary-gonadal axis; however, every endocrine axis may be a target for each EDCs and their action is not limited to a single axis or organ. Several compounds may also have a negative impact on energy metabolic homeostasis altering adipose tissue and promoting obesity, metabolic syndrome, and diabetes. Different mechanism have been proposed to explain these associations but their complexity together with the degree of occupational or environmental exposure, the low standardization of the studies, and the presence of confounding factors have prevented to establish causal relationship between the endocrine disorders and exposure to specific toxicants so far. This manuscript aims to review the state of art of scientific literature regarding the effects of endocrine-disrupting chemicals (EDCs) on endocrine system
"Magic" numbers in Smale's 7th problem
Smale's 7-th problem concerns N-point configurations on the 2-dim sphere
which minimize the logarithmic pair-energy V_0(r) = -ln r averaged over the
pairs in a configuration; here, r is the chordal distance between the points
forming a pair. More generally, V_0(r) may be replaced by the standardized
Riesz pair-energy V_s(r)= (r^{-s} -1)/s, which becomes - ln r in the limit s to
0, and the sphere may be replaced by other compact manifolds. This paper
inquires into the concavity of the map from the integers N>1 into the minimal
average standardized Riesz pair-energies v_s(N) of the N-point configurations
on the 2-sphere for various real s. It is known that v_s(N) is strictly
increasing for each real s, and for s<2 also bounded above, hence "overall
concave." It is (easily) proved that v_{-2}(N) is even locally strictly
concave, and that so is v_s(2n) for s<-2. By analyzing computer-experimental
data of putatively minimal average Riesz pair-energies v_s^x(N) for s in
{-1,0,1,2,3} and N in {2,...,200}, it is found that {v}_{-1}^x(N) is locally
strictly concave, while v_s^x(N) is not always locally strictly concave for s
in {0,1,2,3}: concavity defects occur whenever N in C^{x}_+(s) (an s-specific
empirical set of integers). It is found that the empirical map C^{x}_+(s), with
s in {-2,-1,0,1,2,3}, is set-theoretically increasing; moreover, the percentage
of odd numbers in C^{x}_+(s), s in {0,1,2,3}, is found to increase with s. The
integers in C^{x}_+(0) are few and far between, forming a curious sequence of
numbers, reminiscent of the "magic numbers" in nuclear physics. It is
conjectured that the "magic numbers" in Smale's 7-th problem are associated
with optimally symmetric optimal-energy configurations.Comment: 109 pages, of which 30 are numerical data tables. Thoroughly revised
version, to appear in J. Stat. Phys. under the different title: `Optimal N
point configurations on the sphere: "Magic" numbers and Smale's 7th problem
Quasi-Lie schemes and Emden--Fowler equations
The recently developed theory of quasi-Lie schemes is studied and applied to
investigate several equations of Emden type and a scheme to deal with them and
some of their generalisations is given. As a first result we obtain t-dependent
constants of the motion for particular instances of Emden equations by means of
some of their particular solutions. Previously known results are recovered from
this new perspective. Finally some t-dependent constants of the motion for
equations of Emden type satisfying certain conditions are recovered
MicroShield/ISOCS gamma modeling comparison.
Quantitative radiological analysis attempts to determine the quantity of activity or concentration of specific radionuclide(s) in a sample. Based upon the certified standards that are used to calibrate gamma spectral detectors, geometric similarities between sample shape and the calibration standards determine if the analysis results developed are qualitative or quantitative. A sample analyzed that does not mimic a calibrated sample geometry must be reported as a non-standard geometry and thus the results are considered qualitative and not quantitative. MicroShieldR or ISOCSR calibration software can be used to model non-standard geometric sample shapes in an effort to obtain a quantitative analytical result. MicroShieldR and Canberra's ISOCSR software contain several geometry templates that can provide accurate quantitative modeling for a variety of sample configurations. Included in the software are computational algorithms that are used to develop and calculate energy efficiency values for the modeled sample geometry which can then be used with conventional analysis methodology to calculate the result. The response of the analytical method and the sensitivity of the mechanical and electronic equipment to the radionuclide of interest must be calibrated, or standardized, using a calibrated radiological source that contains a known and certified amount of activity
Biomolecular identification of (CCTG)n mutation in myotonic dystrophy type 2 (DM2) by FISH on muscle biopsy
Myotonic dystrophy type 2 (DM2) is a dominantly inherited disorder with multisystemic clinical features, caused by a CCTG repeat expansion in intron 1 of the zinc finger protein 9 (ZNF9) gene. The mutant transcripts are retained in the nucleus forming multiple discrete foci also called ribonuclear inclusions. The size and the somatic instability of DM2 expansion complicate the molecular diagnosis of DM2. In our study fluorescence-labeled CAGG-repeat oligonucleotides were hybridized to muscle biopsies to investigate if fluorescence in situ hybridization (FISH), a relatively quick and simple procedure, could be used as a method to diagnose DM2. When FISH was performed with (CAGG)5 probe, nuclear foci of mutant RNA were present in all genetically confirmed DM2 patients (n = 17) and absent in all patients with myotonic dystrophy type 1 (DM1; n = 5) or with other muscular disease (n = 17) used as controls. In contrast, foci were observed both in DM1 and DM2 myonuclei when muscle tissue were hybridized with (CAG)6CA probe indicating that this probe is not specific for DM2 identification. The consistent detection of ribonuclear inclusions in DM2 muscles and their absence in DM1, in agreement with the clinical diagnosis and with leukocyte (CCTG)n expansion, suggests that fluorescence in situ hybridization using (CAGG)5 probes, may be a specific method to distinguish between DM1 and DM2. Moreover, the procedure is simple, and readily applicable in any pathology laboratory
Ribonuclear inclusions as biomarker of myotonic dystrophy type 2, even in improperly frozen or defrozen skeletal muscle biopsies
Myotonic dystrophy type 2 (DM2) is a dominantly inherited disorder caused by a CCTG repeat expansion in intron 1 of ZNF9 gene. The size and the somatic instability of DM2 expansion complicate the molecular diagnosis of DM2. In situ hybridization represents a rapid and sensitive method to obtain a definitive diagnosis in few hours, since it allows the direct visualization of the mutant mRNA foci on skeletal muscle sections. This approach makes the muscle biopsy an important tool for definitive diagnosis of DM2. Consequently, a rapid freezing at ultra cold temperature and a good storage of muscle specimens are essential to avoid morphologic alterations and nucleic acids degradation. However incorrect freezing or thawing may accidentally occur. In this work we report that fluorescence in situ hybridization may be applied on improperly frozen or inappropriately stored muscle biopsies since foci of mutant mRNA are well preserved and can still be detected in muscle sections no more useful for histopathological evaluation
Sufficient Conditions for Fast Switching Synchronization in Time Varying Network Topologies
In previous work, empirical evidence indicated that a time-varying network
could propagate sufficient information to allow synchronization of the
sometimes coupled oscillators, despite an instantaneously disconnected
topology. We prove here that if the network of oscillators synchronizes for the
static time-average of the topology, then the network will synchronize with the
time-varying topology if the time-average is achieved sufficiently fast. Fast
switching, fast on the time-scale of the coupled oscillators, overcomes the
descychnronizing decoherence suggested by disconnected instantaneous networks.
This result agrees in spirit with that of where empirical evidence suggested
that a moving averaged graph Laplacian could be used in the master-stability
function analysis. A new fast switching stability criterion here-in gives
sufficiency of a fast-switching network leading to synchronization. Although
this sufficient condition appears to be very conservative, it provides new
insights about the requirements for synchronization when the network topology
is time-varying. In particular, it can be shown that networks of oscillators
can synchronize even if at every point in time the frozen-time network topology
is insufficiently connected to achieve synchronization.Comment: Submitted to SIAD
Homelessness and Incarceration: An Examination of Barriers to Misdemeanor Resolution for the Homeless
Abstract: The relationship between homelessness and crime has been investigated in few studies despite the implications of prior offenses and incarceration on job seekers. This study examined the relationship among homelessness, misdemeanors, incarceration, and misdemeanor resolution. Factors hindering misdemeanor resolution were explored by surveying participants at two Veterans Administration (VA) Stand Downs (n=186). The sample includes the primary service population of homeless veterans and other homeless persons. Respondents reported on factors perceived as limiting them from resolving misdemeanors, along with socio-demographic, homeless status, misdemeanor, and incarceration data. Factor Analysis yielded three factors as barriers that have implications for social work practice
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