Sterile Neutrino Dark Matter in Non-Standard Scenarios

Sterile neutrino with a mass of O(keV) is a well-motivated candidate to play the roleof dark matter (DM), one of the most abundant constituents of our Universe whosenature remains still unknown. It arises as a natural and straightforward extension ofthe particle content of the standard model (SM), it is neutral under all SM charges, itcan be stable over cosmological time scales, and it can be produced in adequate amountin the early Universe to account for today’s DM abundance. In this thesis, we studysterile neutrinos as DM candidates produced in the early Universe through oscillationand collisions induced by their mixing with one of the active neutrino species, i.e. in theframework of the Dodelson-Widrow and the Shi-Fuller mechanisms. In particular, weinvestigate the parameter space of sterile neutrinos in two non-standard scenarios. Thefirst scenario studied is a non-standard cosmological scenario in which the productionof sterile neutrinos is delayed and starts at a critical temperature associated with alow reheating temperature of the Universe or with a dynamical change in the sterileneutrino mass. Here, we show that the discovery potential in terrestrial experiments isconsiderably enhanced. In the second scenario, the production through the Dodelson-Widrow mechanism is modified by non-standard interactions among active neutrinos.An effective formalism to include such neutrino non-standard self-interactions in theDM production is developed, and the sensitivity of the HUNTER experiment to thisspecific model is highlighted. At the same time, we demonstrate that the stringentlimit on sterile neutrino DM coming from observations in the X-ray band should beconsidered model-dependent and can be relaxed in different ways, thereby letting opena window in the parameter space of utmost interest for experimental searches

Del aprendizaje literario del código social al aprendizaje con apoyo visual. La incorporación de la imagen en los manuales de urbanidad

El presente artículo analiza el proceso de penetración de la imagen en los libros escolares de urbanidad desde mediados del siglo xix hasta el primer tercio del siglo xx. Se trata de un largo proceso que implica importantes cambios en las técnicas de ilustración empleadas y sobre todo en las funciones que va adquiriendo la imagen en los trataditos y cartillas de urbanidad, tal como se evidencia a través de la selección de imágenes que se presentan relativas a distintos manuales de esta disciplina escolar

Prospects for Finding Sterile Neutrino Dark Matter at KATRIN

We discuss under what circumstances a signal in upcoming laboratory searchesfor keV-scale sterile neutrinos would be compatible with those particles beinga sizable part or all of dark matter. In the parameter space that will beexperimentally accessible by KATRIN/TRISTAN, strong X-ray limits need to berelaxed and dark matter overproduction needs to be avoided. We discusspostponing the dark matter production to lower temperatures, a reduced sterileneutrino contribution to dark matter, and a reduction of the branching ratio inphotons and active neutrinos through cancellation with a new physics diagram.Both the Dodelson-Widrow and the Shi-Fuller mechanisms for sterile neutrinodark matter production are considered. As a final exotic example, potentialconsequences of CPT violation are discussed.<br

THE HUMAN BETA-DEFENSIN-1 LEVEL FROM SMOKERS WITH CHRONIC PERIODONTITIS

ABSTRACTObjective: The role of human beta-defensin-1 (HBD-1) as an antimicrobial peptide in a smoker's periodontitis is still unclear, this study aimed toanalyze the association of the levels of HBD-1 in smokers and non-smokers with chronic periodontitis.Methods: In total, 104 male subjects, 33-78 years old, were diagnosed to have chronic periodontitis in the Department of Periodontology, Oral DiseaseSpecial Clinic of the University of Indonesia. This cross-sectional study included clinical and laboratory examination. The data collected included thosefrom anamnesis, clinical examination (oral hygiene index Siller, pocket depth, clinical attachment level), and smoking status. The samples were storedat −20°C until testing for HBD-1 level by enzyme-linked immunosorbent assay.Results: The median (min-max) HBD-1 level in the group of mild-moderate chronic periodontitis was 57.61 (0.87-343.58) pg/ml and in the groupof severe periodontitis 15.27 (0.94-198.03) pg/ml (p=0.087). The median (min-max) HBD-1 level in non-smokers with chronic periodontitis was27.82 (0.92-200.58) pg/ml, and in smokers 25.04 (0.87-343.58) pg/ml (p=0.457).Conclusion: There were no significant differences in the HBD-1 levels in subjects with chronic periodontitis regardless of the smoking status orseverity of the disease.Keywords: Periodontitis, β-defensin, Smokers

Severe and moderate seasonal influenza epidemics among Italian healthcare workers: A comparison of the excess of absenteeism

Background: This study aims to quantify the excess of sickness absenteeism among healthcare workers (HCWs), to estimate the impact of a severe versus moderate influenza season and to determine whether the vaccination rates are associated with reduced sickness absence. Methods: We investigated the excess absenteeism that occurred in a large Italian hospital, 5300 HCWs, during the severe influenza season of 2017/2018 and compared it with three moderate flu seasons (2010/2013). Data on influenza vaccinations and absenteeism were obtained from the hospital's databases. The data were split into two periods: the epidemic, from 42 to 17 weeks, and non-epidemic, defined as 18 to 41 weeks, which was used as the baseline. We stratified the absenteeism among HCWs in multiple variables. Results: Our study showed an increased absenteeism among HCWs during the epidemic period of severe season in comparison with non-epidemic periods, the absolute increase correlated with a relative increase of 70% (from 4.05 to 6.68 days/person). Vaccinated HCWs had less excess of absenteeism in comparison with non-vaccinated HCWs (1.74 vs 2.71 days/person). The comparison with the moderate seasons showed a stronger impact on HCW sick absenteeism in the severe season (+0.747days/person, P =.03), especially among nurses and HCWs in contact with patients (+1.53 P <.01; +1.19 P <.01). Conclusions: In conclusion, a severe influenza epidemic has greater impacts on the absenteeism among HCWs than a moderate one. Although at a low rate, a positive effect of vaccination on absenteeism is present, it may support healthcare facilities to recommend vaccinations for their workers

PROMON: a profile monitor of software applications

Software techniques can be efficiently used to increase the dependability of safety-critical applications. Many approaches are based on information redundancy to prevent data and code corruption during the software execution. This paper presents PROMON, a C++ library that exploits a new methodology based on the concept of “Programming by Contract” to detect system malfunctions. Resorting to assertions, pre- and post-conditions, and marginal programmer interventions, PROMON-based applications can reach high level of dependability

Endocrine activities of cortistatin-14 and its interaction with GHRH and ghrelin in humans.

Cortistatin (CST)-14, a neuropeptide with high homology with somatostatin (SS)-14, binds all sst subtypes but, unlike SS, also ghrelin's receptor. In six normal adults, we studied the effects of CST-14 or SS-14 administration (2.0 micro g/kg/h iv) on: 1) GH and insulin secretion; 2) the GH response to GHRH (1.0 microg/kg i.v.); and 3) the GH, prolactin (PRL), ACTH, cortisol, insulin, and glucose responses to ghrelin (1.0 microg/kg i.v.). CST-14 inhibited GH and insulin secretion (P < 0.01) to the same extent of SS-14. The GH response to GHRH was similarly inhibited (P < 0.01) by either CST-14 or SS-14. Ghrelin released more GH than GHRH (P < 0.01); these responses were similarly inhibited (P < 0.05) by either CST-14 or SS-14, that made ghrelin-induced GH rise similar to that after GHRH alone. Neither CST-14 nor SS-14 modified PRL, ACTH, or cortisol responses to ghrelin. The inhibitory effect of CST-14 and SS-14 on insulin was unaffected by ghrelin that, in turn, reduced insulin secretion per se (P < 0.01). Ghrelin increased glucose levels (P < 0.05); CST-14 and SS-14 did not modify this effect. Thus, CST-14 inhibits both basal and stimulated GH secretion in humans to the same extent of SS-14. The GH-releasing activity of ghrelin seems partially resistant to CST-14 as well as SS-14. CST-14 and SS-14 do not affect PRL and ACTH secretion but, like ghrelin, inhibit insulin secretion; the ghrelin-induced inhibition is not additive with that of CST-14 or SS-14, suggesting a common mechanism of action on beta cell secretion

Cortistatin-17 and -14 exert the same endocrine activities as somatostatin in humans

Cortistatin (CST) is a neuropeptide, which binds with high affinity all somatostatin (SS) receptor subtypes and shows high structural homology with SS itself. A receptor specific for CST only, i.e., not recognized by SS, has been recently described in agreement with data reporting that not all CST actions are shared by SS. Interestingly, CST but not SS also binds ghrelin receptor (GHS-R1a) in vitro, suggesting a potential interplay between CST and ghrelin system. The aim of this study was to investigate in humans the endocrine and metabolic activities of human CST-17 in comparison with rat CST-14 that has previously been shown to exert the same endocrine actions of SS in healthy volunteers. To this aim, in six healthy male volunteers (age [median, 3rd-97th centiles]: 28.5; 23.6-34.3 years; Body Mass Index: 23.5; 21.0-25.1 kg/m2), we studied the effects of human CST-17 (2.0 μg/kg/h iv over 120 min), rat CST-14 (2.0 μg/kg/h iv over 120 min) and SS-14 (2.0 μg/kg/h iv over 120 min) on: (a) spontaneous GH, ACTH, PRL, cortisol, insulin and glucose levels; (b) the GH responses to GHRH (1.0 μg/kg iv at 0 min); (c) the GH, PRL, ACTH, cortisol, insulin and glucose responses to ghrelin (1.0 μg/kg iv at 0 min). CST-17 inhibited (p<0.01) basal GH secretion to the same extent of CST-14 and SS-14. Spontaneous PRL, ACTH and cortisol secretion were not significantly modified by CST-17, CST-14 or SS-14. CST-17 as well as CST-14 and SS-14 also inhibited (p<0.05) spontaneous insulin secretion to a similar extent. None of these peptides modified glucose levels. The GH response to GHRH was inhibited to the same extent by CST-17 (p<0.01), CST-14 (p<0.01) and SS-14 (p<0.05). The ghrelin-induced GH response was higher than that elicited by GHRH (p<0.01) and inhibited by CST-17 (p<0.05) as well as by CST-14 (p<0.05) and SS-14 (p<0.01). The PRL, ACTH and cortisol responses to ghrelin were unaffected by CST-17, CST-14 or SS-14. On the other hand, the inhibitory effect of ghrelin on insulin levels was abolished by CST-17, CST-14 or SS-14 (p<0.05) that, in turn, did not modify the ghrelin-induced increase in glucose levels. In conclusion, this study demonstrates that human CST-17 and rat CST-14 exert the same endocrine activities of SS in humans. The endocrine actions of human and rat CST therefore are likely to reflect activation of classical SS receptors