FCNC decays of SM fermions into a dark photon

We analyze a new class of FCNC processes, the $f \to f^{\prime} \, \bar{\gamma}$ decays of a fermion $f$ into a lighter (same-charge) fermion $f^{\prime}$ plus a {\it massless} neutral vector boson, a {\it dark photon} $\bar{\gamma}$. A massless dark photon does not interact at tree level with observable fields, and the $f \!\to\! f^{\prime} \, \bar{\gamma}$ decay presents a characteristic signature where the final fermion $f^{\prime}$ is balanced by a {\it massless invisible} system. Models recently proposed to explain the exponential spread in the standard-model Yukawa couplings can indeed foresee an extra unbroken {\it dark} $U(1)$ gauge group, and the possibility to couple on-shell dark photons to standard-model fermions via one-loop magnetic-dipole kind of FCNC interactions. The latter are suppressed by the characteristic scale related to the mass of heavy messengers, connecting the standard model particles to the dark sector. We compute the corresponding decay rates for the top, bottom, and charm decays ($t\to c\, \bar{\gamma},u\, \bar{\gamma}$, $\;b\to s\, \bar{\gamma},d\, \bar{\gamma}$, and $c\to u \bar{\gamma}$), and for the charged-lepton decays ($\tau \to \mu\, \bar{\gamma}, e\, \bar{\gamma}$, and $\mu \to e \bar{\gamma}$) in terms of model parameters. We find that large branching ratios for both quark and lepton decays are allowed in case the messenger masses are in the discovery range of the LHC. Implications of these new decay channels at present and future collider experiments are briefly discussed.Comment: 44 pages, 9 figures, BBbar constraints and new references included, same version as the published on

Gray phenotype: enhanced fitness strategy for Candida dubliniensis

In this study Yue H. et al described for the first time the gray phenotype and tristable white-gray-opaque transitions in Candida dubliniensis. Here we discuss some intriguing aspects related to this virulence trait of Candida dubliniensis in comparison to Candida albicans and within the wider and complex phenotypic switch phenomenon so typical of the virulence program of these opportunistic pathogenic fungi. In particular, the relationship between the presence of gray phenotype and prevalence of Candida dubliniensis in the oral cavity of HIV-positive subjects is pointed out

Experimental assessment of environmental decay effects in masonry via non destructive diagnostic techniques and mechanical tests

Environmental decay in porous masonry materials, such as brick and mortar, is a widespread problem concerning both new and historic masonry structures. The decay mechanisms are quite complex dependng upon several interconnected parameters and from the interaction with the specific micro-climate. Materials undergo aesthetical and substantial changes in character but while many studies have been carried out, the mechanical aspect has been largely understudied while it bears true importance from the structural viewpoint. A quantitative assessment of the masonry material degradation and how it affects the load-bearing capacity of masonry structures appears missing. The research work carried out, limiting the attention to brick masonry addresses this issue through an experimental laboratory approach via different integrated testing procedures, both non-destructive and mechanical, together with monitoring methods. Attention was focused on transport of moisture and salts and on the damaging effects caused by the crystallization of two different salts, sodium chloride and sodium sulphate. Many series of masonry specimens, very different in size and purposes were used to track the damage process since its beginning and to monitor its evolution over a number of years Athe same time suitable testing techniques, non-destructive, mini-invasive, analytical, of monitoring, were validated for these purposes. The specimens were exposed to different aggressive agents (in terms of type of salt, of brine concentration, of artificial vs. open-air natural ageing, …), tested by different means (qualitative vs. quantitative, non destructive vs. mechanical testing, punctual vs. wide areas, …), and had different size (1-, 2-, 3-header thick walls, full-scale walls vs. small size specimens, brick columns and triplets vs. small walls, masonry specimens vs. single units of brick and mortar prisms, …). Different advanced testing methods and novel monitoring techniques were applied in an integrated holistic approach, for quantitative assessment of masonry health state

A Combination of GPR Survey and Laboratory Rock Tests for Evaluating an Ornamental Stone Deposit in a Quarry Bench

Abstract The paper examines methods of assessing the critical fractures and quality of an ornamental stone deposit. Fracture status was evaluated by an in-situ Ground Penetrating Radar (GPR) test. The resulting 3D GPR model allowed exploration of the extension, shape, and orientation of the detected fractures surfaces. It also identified a rock stratum with a noticeably lower load of critical fractures compared to the other strata. Physico-mechanical properties were investigated by laboratory tests allowing classification of the deposit into quality categories, which provided a promising correlation with the GPR survey results

An integrated human health risk assessment framework for alkylphenols due to drinking water and edible crop consumption

INTRODUCTION The scarcity of clean freshwater is becoming a major issue for present and future generations, especially in densely urbanised areas. This situation promotes the potential cross-contamination of different environmental compartments by contaminants of emerging concern (CECs) which, in fact, have already been detected worldwide in surface water, groundwater and soils. In particular, the CECs released by wastewater treatment plants (WWTPs) can end up both in the recipient surface water and groundwater, both of which are used as drinking water (DW) sources. Furthermore, if those water sources and reclaimed wastewater are used for irrigation, CECs can be directly absorbed by crops intended for human consumption or accumulate in soil and translocate to crops over time. Hence, both DW and edible crops are critical CEC exposure pathways for humans, the combined effect of which requires further investigation. This work is aimed at developing an integrated framework for a quantitative chemical risk assessment due to CECs in complex multiple-use scenarios, combining DW and edible crop consumption, as a decision-making support tool for optimising solutions to minimise risks and social costs. METHODOLOGY The developed procedure includes several steps. Firstly, the analysed system boundaries are defined, to evaluate all the phenomena affecting the fate of CECs from source to end user. Then, CEC migration (e.g. diffusion in surface water, infiltration in soil, uptake by food crops) and human exposure (via water and edible crop consumption) are modelled in an integrated framework as a function of boundary conditions, CECs and by-products characteristics, and proposed interventions. Exposure models are calibrated through literature data, field monitoring and lab tests where, for instance, the CECs’ fate and uptake by vegetables from contaminated soils have been investigated. In the hazard assessment step, a toxicological characterisation was performed to obtain single CEC adverse effect potencies, aimed at applying the Relative Potency Factors methodology for combining CECs that affect the same endpoint. Lastly, exposure and hazard assessment steps are combined to quantitatively estimate the risk to human health from a mixture of CECs, which includes uncertainty analyses to account for knowledge gaps and to provide decision-makers with the confidence level of the risk estimation. RESULTS The developed quantitative risk assessment procedure has been applied to a case study on the mixture of two alkylphenols, i.e. bisphenol-A (BPA) and nonylphenol (NP), used as reference CECs. Literature and field-monitoring data were used to feed the model, with an estimate of BPA and NP concentration in DW up to 0.1 and 0.35 μg/L, respectively, as a function of different system boundary conditions. As for their uptake in edible crops, lab tests with contaminated soil (BPA=75 μg/kg and NP=10 mg/kg, according to the range reported in literature for soil irrigated with reclaimed wastewater or amended with biosolids) demonstrated a significant transfer of NP from soil to vegetables, with concentrations of up to 230 μg/kg fresh weight (f.w.) in the edible parts. No BPA (<8 μg/kg f.w.) was found in vegetables, unlike its metabolite para-hydroxybenzoic acid (up to 56 μg/kg f.w). Those results highlight that both DW and edible crop consumption exposure pathways are critical for the risk to human health due to BPA, NP and their by-products. Several interventions in WWTPs or in DW treatment plants and distribution networks were simulated, demonstrating promising cumulative risk reduction. DISCUSSION Integrated modelling of the fate of CEC mixtures in complex multiple-use water systems, combined with quantitative risk assessment, has proven to be an effective tool to identify the main causes of risk for humans and to assign the various CEC source contributions. Lab tests proved to be useful to investigate the fate of CECs, including metabolites, in the soil system and potential transfer to food crops, corroborating the information from literature and monitoring data for model calibration. Integrated modelling also made it possible to explore several intervention strategies to be adopted at different points of the water system, identifying those that achieve the minimum overall mixture risk. Moreover, in addition to CEC toxicological characterisation, this procedure allows decision-makers to prioritise CECs to be regulated not only based on their exposure levels but looking at their contribution to the overall mixture risk. Lastly, uncertainty analysis made it possible to properly consider the availability and quality of CEC data, especially as regards their physical-chemical behaviour and toxicity, thereby providing the degree of confidence for the estimated risk, which is a key factor for taking informed decisions concerning CEC

Pertussis epidemiology in Argentina: TRENDS after the introduction of maternal immunisation

Data on the impact of the recently recommended maternal pertussis vaccination are promising, but still insufficient to universalise this approach. We thus compared the epidemiological data prior to the implementation of this vaccination strategy in Argentina (2012) with the figures reported after 2012. During that 2010–2016 period, two outbreaks occurred, one in 2011 and another in 2016. In the former, the incidence was 6.9/100 000 inhabitants and the casefatality rate 2.6%. Thereafter, a decline in incidence was detected until 2014. During 2015 and 2016 an increase in the incidence transpired, but this rise was fortunately not accompanied by one in the case fatality ratio. Indeed, in 2016 the case fatality ratio was the lowest (0.6%). Moreover, during the 2016 outbreak, the incidence (3.9/100 000 inhabitants) and the case severity detected in the most vulnerable population (infants 0–2 months) were both lower than those in 2011. Consistent with this pattern, in 2016, in the most populated province of Argentina (Buenos Aires), the case percentage with laboratory-positive results indicating a high number of symptoms (59.1% of the total cases) diminished compared with that detected in the 2011 outbreak without maternal immunisation (71.9%). Using the mathematical model of pertussis transmission we previously designed, we assessed the effect of vaccination during pregnancy on infant incidence. From comparisons between the epidemiological data made through calculations, emerged the possibility that vaccinating women during pregnancy would benefit the infants beyond age 2 months, specifically in the 2–12-month cohort.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

Therapeutic activity of a Saccharomyces cerevisiae-based probiotic and inactivated whole yeast on vaginal candidiasis

Vulvovaginal candidiasis is the most prevalent vaginal infection worldwide and Candida albicans is its major agent. Vulvovaginal candidiasis is characterized by disruption of the vaginal microbiota composition, as happens following large spectrum antibiotic usage. Recent studies support the effectiveness of oral and local probiotic treatment for prevention of recurrent vulvovaginal candidiasis. Saccharomyces cerevisiae is a safe yeast used as, or for, the production of ingredients for human nutrition and health. Here, we demonstrate that vaginal administration of probiotic Saccharomyces cerevisiae live yeast (GI) and, in part, inactivated whole yeast Saccharomyces cerevisiae (IY), used as post-challenge therapeutics, was able to positively influence the course of vaginal candidiasis by accelerating the clearance of the fungus. This effect was likely due to multiple interactions of Saccharomyces cerevisiae with Candida albicans. Both live and inactivated yeasts induced coaggregation of Candida and consequently inhibited its adherence to epithelial cells. However, only the probiotic yeast was able to suppress some major virulence factors of Candida albicans such as the ability to switch from yeast to mycelial form and the capacity to express several aspartyl proteases. The effectiveness of live yeast was higher than that of inactivated whole yeast suggesting that the synergy between mechanical effects and biological effects were dominant over purely mechanical effects. The protection of epithelial cells to Candida-induced damage was also observed. Overall, our data show for the first time that Saccharomyces cerevisiae-based ingredients, particularly the living cells, can exert beneficial therapeutic effects on a widespread vaginal mucosal infection

Secretory Aspartyl Proteinases Cause Vaginitis and Can Mediate Vaginitis Caused by Candida albicans in Mice

Vaginal inflammation (vaginitis) is the most common disease caused by the human-pathogenic fungus Candida albicans. Secretory aspartyl proteinases (Sap) are major virulence traits of C. albicans that have been suggested to play a role in vaginitis. To dissect the mechanisms by which Sap play this role, Sap2, a dominantly expressed member of the Sap family and a putative constituent of an anti-Candida vaccine, was used. Injection of full-length Sap2 into the mouse vagina caused local neutrophil influx and accumulation of the inflammasome-dependent interleukin-1β (IL-1β) but not of inflammasome-independent tumor necrosis factor alpha. Sap2 could be replaced by other Sap, while no inflammation was induced by the vaccine antigen, the N-terminal-truncated, enzymatically inactive tSap2. Anti-Sap2 antibodies, in particular Fab from a human combinatorial antibody library, inhibited or abolished the inflammatory response, provided the antibodies were able, like the Sap inhibitor Pepstatin A, to inhibit Sap enzyme activity. The same antibodies and Pepstatin A also inhibited neutrophil influx and cytokine production stimulated by C. albicans intravaginal injection, and a mutant strain lacking SAP1, SAP2, and SAP3 was unable to cause vaginal inflammation. Sap2 induced expression of activated caspase-1 in murine and human vaginal epithelial cells. Caspase-1 inhibition downregulated IL-1β and IL-18 production by vaginal epithelial cells, and blockade of the IL-1β receptor strongly reduced neutrophil influx. Overall, the data suggest that some Sap, particularly Sap2, are proinflammatory proteins in vivo and can mediate the inflammasome-dependent, acute inflammatory response of vaginal epithelial cells to C. albicans. These findings support the notion that vaccine-induced or passively administered anti-Sap antibodies could contribute to control vaginitis

Anxiety, depression, and glycemic control during Covid-19 pandemic in youths with type 1 diabetes.

Abstract Objectives Our study aims to assess the impact of lockdown during the coronavirus disease 2019 pandemic on glycemic control and psychological well-being in youths with type 1 diabetes. Methods We compared glycemic metrics during lockdown with the same period of 2019. The psychological impact was evaluated with the Test of Anxiety and Depression. Results We analyzed metrics of 117 adolescents (87% on Multiple Daily Injections and 100% were flash glucose monitoring/continuous glucose monitoring users). During the lockdown, we observed an increase of the percentage of time in range (TIR) (p<0.001), with a significant reduction of time in moderate (p=0.002), and severe hypoglycemia (p=0.001), as well as the percentage of time in hyperglycemia (p<0.001). Glucose variability did not differ (p=0.863). The glucose management indicator was lower (p=0.001). 7% of youths reached the threshold-score (≥115) for anxiety and 16% for depression. A higher score was associated with lower TIR [p=0.028, p=0.012]. Conclusions Glycemic control improved during the first lockdown period with respect to the previous year. Symptoms of depression and anxiety were associated with worse glycemic control; future researches are necessary to establish if this improvement is transient and if psychological difficulties will increase during the prolonged pandemic situation