181 research outputs found
TOPSEM, TwO Parameters Semi Empirical Model: Galaxy Evolution and Bulge/Disk Dicothomy from Two-Stage Halo Accretion
In recent years, increasing attention has been devoted to semi empirical,
data-driven models to tackle some aspects of the complex and still largely
debated topic of galaxy formation and evolution. We here present a new semi
empirical model whose marking feature is simplicity: it relies on solely two
assumptions, one initial condition and two free parameters. Galaxies are
connected to evolving dark matter haloes through abundance matching between
specific halo accretion rate (sHAR) and specific star formation rate (sSFR).
Quenching is treated separately, in a fully empirical way, to marginalize over
quiescent galaxies and test our assumption on the sSFR evolution without
contaminations from passive objects. Our flexible and transparent model is able
to reproduce the observed stellar mass functions up to , giving
support to our hypothesis of a monotonic relation between sHAR and sSFR. We
then exploit the model to test a hypothesis on morphological evolution of
galaxies. We attempt to explain the bulge/disk bimodality in terms of the two
halo accretion modes: fast and slow accretion. Specifically, we speculate that
bulge/spheroidal components might form during the early phase of fast halo
growth, while disks form during the later phase of slow accretion. We find
excellent agreement with both the observational bulge and elliptical mass
functions.Comment: 22 pages, 13 Figure
Binge and Emotional Eating in obese subjects seeking weight loss treatment
Objective: Binge Eating Disorder (BED) is highly prevalent among individuals seeking weight loss treatment. Considering the possible trigger factors for BED, different studies focused on the role of emotional eating. The present study compared threshold, subthreshold BED, and subjects without BED in a population of overweight/obese individuals seeking weight loss treatment, considering the anamnesis, the eating disorder specific and general psychopathology, the organic and psychiatric comorbidity, the emotional eating as a trigger factor for binge eating, and the quality of life. Design: cross-sectional survey.Subjects: Four hundred thirty eight overweight subjects seeking weight loss treatment have been enrolled in the study. Measurements: Subjects have been evaluated by means of a clinical interview (SCID I) and different self-reported questionnaires (Eating Disorder Examination Questionnaire, Binge Eating Scale, Beck Depression Inventory, Spielberg's State-Trait Anxiety Inventory, Symptom Checklist 90, Emotional Eating Scale, and Obesity Related Well-Being questionnaire). Results: One hundred and five subjects (24% of the sample) fulfilled the DSM-IV criteria of lifetime BED, 146 (33.3%) fulfilled the criteria of lifetime subthreshold BED, and 187 (42.7%) subjects were diagnosed overweight non-BED. No correlations between the binges frequencies and the overweight levels were found. All the three groups showed high psychiatric comorbidities, and the three groups significantly differed in terms of emotional eating, which was positively correlated to the binge eating frequencies. Conclusions: Threshold and subthreshold BED deserve a careful psychopathological investigation and emotional eating seems to play a key role as trigger factor for binge eating. Obesity is associated with a high psychiatric comorbidity and a low quality of life, independently from the specific and general eating disorder psychopathology
Mille general practice governance (MilleGPG): an interactive tool to address an effective quality of care through the Italian general practice network.
The General Practitioner (GP) is the "gate-keeper" in patients' treatment and management. Herein, the use of Electronic Medical Records (EMR) could represent an effective support for GPs. Software capable of managing EMRs are available and they can be functional in adopting treatment guidelines by means of computerized prompts and reminders systems. These tools can be also programmed to include clinical algorithms with which to measure the quality of care to make possible the identification of clinical issues, and to take actions for addressing them. Given that similar tools were not available in Italy, we developed MilleGPG, an interactive tool aimed to evaluate, and subsequently improve the quality of care among patients with comorbidities
Dark Matter in Fractional Gravity I: Astrophysical Tests on Galactic Scales
[abridged] We explore the possibility that the dark matter (DM) component in
galaxies may originate fractional gravity. In such a framework, the standard
law of inertia continues to hold, but the gravitational potential associated to
a given DM density distribution is determined by a modified Poisson equation
including fractional derivatives (i.e., derivatives of non-integer type), that
are meant to describe non-local effects. We derive analytically the expression
of the potential that in fractional gravity corresponds to various spherically
symmetric density profiles, including the Navarro-Frenk-White (NFW)
distribution that is usually exploited to describe virialized halos of
collisionless DM as extracted from body cosmological simulations. We show
that in fractional gravity the dynamics of a test particle moving in a cuspy
NFW density distribution is substantially altered with respect to the Newtonian
case (i.e., basing on the standard Poisson equation), mirroring what in
Newtonian gravity would instead be sourced by a density profile with an inner
core. We test the fractional gravity framework on galactic scales, showing
that: (i) it can provide accurate fits to the stacked rotation curves of
galaxies with different properties; (ii) it can reproduce to reasonable
accuracy the observed shape and scatter of the radial acceleration relation
(RAR); (iii) it can properly account for the universal surface density and the
core radius vs. disk scale-length scaling relations. Finally, we discuss the
possible origin of the fractional gravity behavior as a fundamental or emerging
property of the elusive DM component.Comment: 30 pages, 11 figures, Accepted by Ap
Type II diabetes and impaired glucose tolerance due to severe hyperinsulinism in patients with 1p36 deletion syndrome and a Prader-Willi-like phenotype
BACKGROUND: Deletion of the subtelomeric region of 1p36 is one of the most common subtelomeric deletion syndromes. In monosomy 1p36, the presence of obesity is poorly defined, and glucose metabolism deficiency is rarely reported. However, the presence of a typical Prader-Willi-like phenotype in patients with monosomy 1p36 is controversial. CASE PRESENTATION: In this report, we describe two female patients, one who is 6 years 2 months of age and another who is 10 years 1 month of age, both referred to our hospital for obesity and a Prader-Willi-like phenotype. These patients presented with severe obesity (body mass index [BMI] was 26.4 and 27.7, respectively), hyperphagia and developmental delay. Analysis of basal hormone levels showed normal thyroid function and adrenal function but considerable basal hyperinsulinism (the insulin levels were 54.5 and 49.2 μU/ml, respectively). In patient 1, glycaemia was 75 mg/dl (HOMA-R 10.09), and the HbA1c level was 6.1%; in patient 2, glycaemia was 122 mg/dl, and the HbA1c level was 6.6% (HOMA-R 14.82). An oral glucose tolerance test demonstrated impaired glucose tolerance and diabetes mellitus with marked insulin resistance (the peak insulin level for each patient was 197 and 279 μU/mL, respectively, while the 120’ insulin level of each patient was 167 and 234 μU/mL, respectively). CONCLUSION: some patients with monosomy 1p36 may show Prader-Willi-like physical and physiologic characteristics such as obesity and hyperinsulinism with impaired glucose metabolism, which can cause type II diabetes mellitus. Further studies are necessary to evaluate these findings
The weak dependence of velocity dispersion on disc fractions, mass-to-light ratio, and redshift: implications for galaxy and black hole evolution
Velocity dispersion ( σ) is a key driver for galaxy structure and evolution. We here present a comprehensive semi-empirical approach to compute σvia detailed Jeans modelling assuming both a constant and scale-dependent mass-to-light ratio M ∗/ L . We compare with a large sample of local galaxies from MaNGA and find that both models can reproduce the Faber–Jackson (FJ) relation and the weak dependence of σon bulge-to-total (B/T) ratio (for B/T 0.25). The dynamical-to-stellar mass ratio within R R e can be fully accounted for by a gradient in M ∗/ L . We then build velocity dispersion evolutionary tracks σap [ M ∗, z] (within an aperture) along the main progenitor dark matter haloes assigning stellar masses, ef fecti ve radii, and S ´ersic indices via a variety of abundance matching and empirically moti v ated relations. We find: (1) clear e vidence for do wnsizing in σap [ M ∗, z] along the progenitor tracks; (2) at fixed stellar mass σ∝ (1 + z) 0.2 −0.3 depending on the presence or not of a gradient in M ∗/ L . We extract σap [ M ∗, z] from the TNG50 hydrodynamic simulation and find very similar results to our models with constant M ∗/ L . The increasing dark matter fraction within R e tends to flatten the σap [ M ∗, z] along the progenitors at z 1 in constant M ∗/ L models, while σap [ M ∗, z] have a steeper evolution in the presence of a stellar gradient. We then show that a combination of mergers and gas accretion is likely responsible for the constant or increasing σap [ M ∗, z] with time. Finally, our σap [ M ∗, z] are consistent with a nearly constant and steep M bh −σrelation at z 2, with black hole masses derived from the L X −M ∗relation
Cosmic evolution of the incidence of active galactic nuclei in massive clusters : simulations versus observations
Peer reviewe
Long-term auxological and endocrinological evaluation of patients with 9p trisomy: a focus on the growth hormone-insulin-like growth factor-I axis
Long-term auxological and endocrinological evaluation of patients with 9p trisomy: a focus on the growth hormone-insulin-like growth factor-I axis
BACKGROUND:
Trisomy 9p is an uncommon anomaly characterised by mental retardation, head and facial abnormalities, congenital heart defects, kidney abnormalities, and skeletal malformations. Affected children may also show growth and puberty retardation with delayed bone age. Auxological and endocrinological data are lacking for this syndrome.
METHODS:
We describe three girls and one boy with 9p trisomy showing substantial growth failure, and we evaluate the main causes of their short stature.
RESULTS:
The target height was normal in all families, ranging from 0.1 and -1.2 standard deviation scores (SDS). The patients had a low birth-weight (from -1.2 to -2.4 SDS), birth length (from -1.1 to -3.2 SDS), and head circumference (from -0.5 to -1.6 SDS). All patients presented with substantial growth (height) retardation at the time of 9p trisomy diagnosis (from -3.0 to -3.8 SDS).The growth hormone stimulation test revealed a classic growth hormone (GH) deficiency (GHD) in patients 1, 3, and 4. In contrast, patient 2 was determined to have a GH neurosecretory dysfunction (GHNSD). The plasma concentrations of IGF-I and IGFBP-3 were low in all patients for their ages and sexes (from -2.0 to -3.4 SDS, and from -1.9 to -2.8 SDS, respectively).The auxological follow-up showed that those patients who underwent rhGH treatment exhibited a very good response to the GH therapy, whereas patients 3 and 4, whose families chose not to use rhGH treatment, did not experience any significant catch-up growth.
CONCLUSIONS:
GH deficiency appears to be a possible feature of patients with 9p trisomy syndrome. These patients, particularly those with growth delays, should be evaluated for GH secretion
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