Fully Geant4 compatible package for the simulation of Dark Matter in fixed target experiments

We present the package for the simulation of DM (Dark Matter) particles in fixed target experiments. The most convenient way of this simulation (and the only possible way in the case of beam-dump) is to simulate it in the framework of the program for tracing particles in the experimental setup. One of the most popular such programs is Geant4. Specifically, the package includes the processes of DM particles production via electron and muon bremsstrahlung off nuclei, resonant in-flight positron annihilation on atomic electrons and gamma to ALP (axion-like particles) conversion on nuclei. Four types of DM mediator particles are considered: vector, scalar, pseudoscalar and axial vector. In particular, for bremsstrahlung the total cross sections are calculated at exact tree level (ETL). The code handles both the case of invisible DM mediator decay and of visible decay into $e^+e^-$ (or into $\gamma \gamma$ in the case of ALP). The software consists of a collection of different classes, inheriting from the Geant4 framework classes, thus the expected use of this package is to include it in a Geant4-based code for the simulation of particles propagation and interaction in the detector. As an example of its usage, we discuss the results obtained from the simulation of a typical active beam-dump experiment, considering $5 \times 10^{12}$ 100 GeV electrons impinging on a lead/plastic scintillator active thick target, showing the expected sensitivity for the four types of DM mediator particles mentioned above.Comment: 10 pages, 4 figure

GABAergic and Cortical and Subcortical Glutamatergic Axon Terminals Contain CB1 Cannabinoid Receptors in the Ventromedial Nucleus of the Hypothalamus

Background: Type-1 cannabinoid receptors (CB1R) are enriched in the hypothalamus, particularly in the ventromedial hypothalamic nucleus (VMH) that participates in homeostatic and behavioral functions including food intake. Although CB1R activation modulates excitatory and inhibitory synaptic transmission in the brain, CB1R contribution to the molecular architecture of the excitatory and inhibitory synaptic terminals in the VMH is not known. Therefore, the aim of this study was to investigate the precise subcellular distribution of CB1R in the VMH to better understand the modulation exerted by the endocannabinoid system on the complex brain circuitries converging into this nucleus. Methodology/Principal Findings: Light and electron microscopy techniques were used to analyze CB1R distribution in the VMH of CB1R-WT, CB1R-KO and conditional mutant mice bearing a selective deletion of CB1R in cortical glutamatergic (Glu-CB1R-KO) or GABAergic neurons (GABA-CB1R-KO). At light microscopy, CB1R immunolabeling was observed in the VMH of CB1R-WT and Glu-CB1R-KO animals, being remarkably reduced in GABA-CB1R-KO mice. In the electron microscope, CB1R appeared in membranes of both glutamatergic and GABAergic terminals/preterminals. There was no significant difference in the percentage of CB1R immunopositive profiles and CB1R density in terminals making asymmetric or symmetric synapses in CB1R-WT mice. Furthermore, the proportion of CB1R immunopositive terminals/preterminals in CB1R-WT and Glu-CB1R-KO mice was reduced in GABA-CB1R-KO mutants. CB1R density was similar in all animal conditions. Finally, the percentage of CB1R labeled boutons making asymmetric synapses slightly decreased in Glu-CB1R-KO mutants relative to CB1R-WT mice, indicating that CB1R was distributed in cortical and subcortical excitatory synaptic terminals. Conclusions/Significance: Our anatomical results support the idea that the VMH is a relevant hub candidate in the endocannabinoid-mediated modulation of the excitatory and inhibitory neurotransmission of cortical and subcortical pathways regulating essential hypothalamic functions for the individual's survival such as the feeding behavior.L. Reguero is in receipt of a Predoctoral Fellowship from the Basque Country Government (BFI 07.286); I. Buceta is in receipt of a Predoctoral Fellowship from the Basque Country University. Dr. Pedro Grandes' laboratory is supported by The Basque Country Government grant GIC07/70-IT-432-07, by Ministerio de Ciencia e Innovacion (SAF2009-07065) and by Red de Trastornos Adictivos, RETICS, Instituto de Salud Carlos III, MICINN, grant RD07/0001/2001. Dr. Giovanni Marsicano's laboratory is supported by AVENIR/INSERM (with the Fondation Bettencourt-Schueller), by ANR (ANR-06-NEURO-043-01), by European Foundation for the Study of Diabetes (EFSD), by the EU-FP7 (REPROBESITY, contract number HEALTH-F2-2008-223713) and European Commission Coordination Action ENINET (contract number LSHM-CT-2005-19063). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Synthesis of 4-substituted-1,2-dihydroquinolines by means of gold-catalyzed intramolecular hydroarylation reaction of n-ethoxycarbonyl-n-propargylanilines

An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-Npropargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-metasubstituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning

Development of the fully Geant4 compatible package for the simulation of Dark Matter in fixed target experiments

The search for new comparably light (well below the electroweak scale) feebly interacting particles is an exciting possibility to explain some mysterious phenomena in physics, among them the origin of Dark Matter. The sensitivity study through detailed simulation of projected experiments is a key point in estimating their potential for discovery. Several years ago we created the DMG4 package for the simulation of DM (Dark Matter) particles in fixed target experiments. The natural approach is to integrate this simulation into the same program that performs the full simulation of particles in the experiment setup. The Geant4 toolkit framework was chosen as the most popular and versatile solution nowadays. The simulation of DM particles production by this package accommodates several possible scenarios, employing electron, muon or photon beams and involving various mediators, such as vector, axial vector, scalar, pseudoscalar, or spin 2 particles. The bremsstrahlung, annihilation or Primakoff processes can be simulated. The package DMG4 contains a subpackage DarkMatter with cross section methods weakly connected to Geant4. It can be used in different frameworks. In this paper, we present the latest developments of the package, such as extending the list of possible mediator particle types, refining formulas for the simulation and extending the mediator mass range. The user interface is also made more flexible and convenient. In this work, we also demonstrate the usage of the package, the improvements in the simulation accuracy and some cross check validations.Comment: 17 pages, 11 figures, 1 tabl

Toward a Generative Modeling Analysis of CLAS Exclusive 2 Photoproduction

AI-supported algorithms, particularly generative models, have been successfully used in a variety of different contexts. This work employs a generative modeling approach to unfold detector effects specifically tailored for exclusive reactions that involve multiparticle final states. Our study demonstrates the preservation of correlations between kinematic variables in a multidimensional phase space. We perform a full closure test on two-pion photoproduction pseudodata generated with a realistic model in the kinematics of the Jefferson Lab CLAS g11 experiment. The overlap of different reaction mechanisms leading to the same final state associated with the CLAS detector’s nontrivial effects represents an ideal test case for AI-supported analysis. Uncertainty quantification performed via bootstrap provides an estimate of the systematic uncertainty associated with the procedure. The test demonstrates that GANs can reproduce highly correlated multidifferential cross sections even in the presence of detector-induced distortions in the training datasets, and provides a solid basis for applying the framework to real experimental data

Digital Transformation of Public Services in a Startup-Based Environment: Job Perceptions, Relationships, Potentialities and Restrictions

Digital transformation in public administration needs to be accompanied by more dynamic and intelligent strategies, which effect cultural change. Inspired by the business culture of startups, in 2021 the Brazilian government created the StartUp GOV.BR program to develop and accelerate the development of digital transformation projects within the Federal Government. This program aims to make digital transformation processes more proactive and flexible and generate more profitable operations. In this work, we investigated the perception of ICT practitioners (members of startups) about the program and the issues that surround it. Our goal was to identify relations, potentialities and restrictions of this program to contribute to outlining growth strategies, as well as the assets and capabilities needed to successfully transform digital public services in a startup-based environment. For this purpose, we conducted 23 focus groups with up to 12 people, totaling 175 participants. Then, we fully transcribed and qualitatively analyzed the data from each of the focus groups based on Grounded Theory. As a result, we developed maps of relationships between categories, along with narratives that help explain and understand the members’ perception of the StartUp GOV.BR program. We also listed 34 points for improvement and 62 actions to be taken to improve the program. The results achieved in this work can contribute to a research agenda of initiatives towards the Digital Transformation of public services in governments around the world combining innovative digital strategies based on the perspective of professionals

Preoperative anaemia and clinical outcomes in the South African Surgical Outcomes Study

Background. In high-income countries, preoperative anaemia has been associated with poor postoperative outcomes. To date, no large study has investigated this association in South Africa (SA). The demographics of SA surgical patients differ from those of surgical patients in the European and Northern American settings from which the preoperative anaemia data were derived. These associations between preoperative anaemia and postoperative outcomes are therefore not necessarily transferable to SA surgical patients.Objectives. The primary objective was to determine the association between preoperative anaemia and in-hospital mortality in SA adult non-cardiac, non-obstetric patients. The secondary objectives were to describe the association between preoperative anaemia and (i) critical care admission and (ii) length of hospital stay, and the prevalence of preoperative anaemia in adult SA surgical patients.Methods. We performed a secondary analysis of the South African Surgical Outcomes Study (SASOS), a large prospective observational study of patients undergoing inpatient non-cardiac, non-obstetric surgery at 50 hospitals across SA over a 1-week period. To determine whether preoperative anaemia is independently associated with mortality or admission to critical care following surgery, we conducted a multivariate logistic regression analysis that included all the independent predictors of mortality and admission to critical care identified in the original SASOS model.Results. The prevalence of preoperative anaemia was 1 727/3 610 (47.8%). Preoperative anaemia was independently associated with in-hospital mortality (odds ratio (OR) 1.657, 95% confidence interval (CI) 1.055 - 2.602; p=0.028) and admission to critical care (OR 1.487, 95% CI 1.081 - 2.046; p=0.015).Conclusions. Almost 50% of patients undergoing surgery at government-funded hospitals in SA had preoperative anaemia, which was independently associated with postoperative mortality and critical care admission. These numbers indicate a significant perioperative risk, with a clear need for quality improvement programmes that may improve surgical outcomes. Long waiting lists for elective surgery allow time for assessment and correction of anaemia preoperatively. With a high proportion of patients presenting for urgent or emergency surgery, perioperative clinicians in all specialties should educate themselves in the principles of patient blood management.Â