Antiprotons from Dark Matter: Effects of a Position-Dependent Diffusion Coefficient

Energetic antiprotons in cosmic rays can serve as an important indirect signature of dark matter. Conventionally, the antiproton flux from dark matter decays or annihilations is calculated by solving the transport equation with a space-independent diffusion coefficient within the diffusion zone of the galaxy, and assuming free propagation outside this zone. Antiproton sources outside of the diffusion zone are ignored. In reality, it is far more likely that the diffusion coefficient increases smoothly with distance from the disk, and the outlying part of the dark matter halo ignored in the conventional approach can be significant, containing as much as 90% of the galactic dark matter by mass in some models. We extend the conventional approach to address these issues. We obtain analytic approximations and numerical solutions for antiproton flux assuming that the diffusion coefficient increases exponentially with the distance from the disk, and including contributions from dark matter annihilations/decays in essentially the full dark matter halo. We find that the antiproton flux predicted in this model deviates from the conventional calculation for the same dark matter parameters by up to about 25%.Comment: minor corrections and clarifications. main results and conclusions unchanged. final version accepted for publication in PR

Right-handed Neutrinos and R(D(∗))R(D^{(*)})

We explore scenarios where the $R(D^{(*)})$ anomalies arise from semitauonic decays to a right-handed sterile neutrino. We perform an EFT study of all five simplified models capable of generating at tree-level the lowest dimension electroweak operators that give rise to this decay. We analyze their compatibility with current $R(D^{(*)})$ data and other relevant hadronic branching ratios, and show that one simplified model is excluded by this analysis. The remainder are compatible with collider constraints on the mediator semileptonic branching ratios, provided the mediator mass is of order TeV. We also discuss the phenomenology of the sterile neutrino itself, which includes possibilities for displaced decays at colliders and direct searches, measurable dark radiation, and gamma ray signals.Comment: 30 pages, 13 figures. Updated collider constraints and discussions. Matches published version in JHE

Financial and Economic Analysis of CRP, Row Crop, and White Pine Production on Erodible Lands of Southern Ohio

Exact date of working paper unknown

The effect of applied magnetic field on photocurrent generation in poly-3-hexylthiophene:[6,6]-phenyl C61-butyric acid methyl ester photovoltaic devices

This is the author’s version of a work that was accepted for publication in Journal of Physics: Condensed Matter http://dx.doi.org/10.1088/0953-8984/20/45/45220

R(D(∗))R(D^{(*)}) from W′W' and right-handed neutrinos

We provide an ultraviolet (UV) complete model for the $R(D^{(*)})$ anomalies, in which the additional contribution to semi-tauonic $b \to c$ transitions arises from decay to a right-handed sterile neutrino via exchange of a TeV-scale $SU(2)_L$ singlet $W'$. The model is based on an extension of the Standard Model (SM) hypercharge group, $U(1)_Y$, to the $SU(2)_V\times U(1)'$ gauge group, containing several pairs of heavy vector-like fermions. We present a comprehensive phenomenological survey of the model, ranging from the low-energy flavor physics, direct searches at the LHC, to neutrino physics and cosmology. We show that, while the $W'$ and $Z'$-induced constraints are important, it is possible to find parameter space naturally consistent with all the available data. The sterile neutrino sector also offers rich phenomenology, including possibilities for measurable dark radiation, gamma ray signals, and displaced decays at colliders.Comment: 26 pages, 5 figure

The IBMAP approach for Markov networks structure learning

In this work we consider the problem of learning the structure of Markov networks from data. We present an approach for tackling this problem called IBMAP, together with an efficient instantiation of the approach: the IBMAP-HC algorithm, designed for avoiding important limitations of existing independence-based algorithms. These algorithms proceed by performing statistical independence tests on data, trusting completely the outcome of each test. In practice tests may be incorrect, resulting in potential cascading errors and the consequent reduction in the quality of the structures learned. IBMAP contemplates this uncertainty in the outcome of the tests through a probabilistic maximum-a-posteriori approach. The approach is instantiated in the IBMAP-HC algorithm, a structure selection strategy that performs a polynomial heuristic local search in the space of possible structures. We present an extensive empirical evaluation on synthetic and real data, showing that our algorithm outperforms significantly the current independence-based algorithms, in terms of data efficiency and quality of learned structures, with equivalent computational complexities. We also show the performance of IBMAP-HC in a real-world application of knowledge discovery: EDAs, which are evolutionary algorithms that use structure learning on each generation for modeling the distribution of populations. The experiments show that when IBMAP-HC is used to learn the structure, EDAs improve the convergence to the optimum

The exchanged EF-hands in calmodulin and troponin C chimeras impair the Ca2+-induced hydrophobicity and alter the interaction with Orai1: a spectroscopic, thermodynamic and kinetic study

Background Calmodulin (CaM) plays an important role in Ca2+-dependent signal transduction. Ca2+ binding to CaM triggers a conformational change, forming a hydrophobic patch that is important for target protein recognition. CaM regulates a Ca2+-dependent inactivation process in store-operated Ca2+entry, by interacting Orai1. To understand the relationship between Ca2+-induced hydrophobicity and CaM/Orai interaction, chimera proteins constructed by exchanging EF-hands of CaM with those of Troponin C (TnC) are used as an informative probe to better understand the functionality of each EF-hand. Results ANS was used to assess the context of the induced hydrophobic surface on CaM and chimeras upon Ca2+ binding. The exchanged EF-hands from TnC to CaM resulted in reduced hydrophobicity compared with wild-type CaM. ANS lifetime measurements indicated that there are two types of ANS molecules with rather distinct fluorescence lifetimes, each specifically corresponding to one lobe of CaM or chimeras. Thermodynamic studies indicated the interaction between CaM and a 24-residue peptide corresponding to the CaM-binding domain of Orail1 (Orai-CMBD) is a 1:2 CaM/Orai-CMBD binding, in which each peptide binding yields a similar enthalpy change (ΔH = −5.02 ± 0.13 kcal/mol) and binding affinity (Ka = 8.92 ± 1.03 × 105 M−1). With the exchanged EF1 and EF2, the resulting chimeras noted as CaM(1TnC) and CaM(2TnC), displayed a two sequential binding mode with a one-order weaker binding affinity and lower ΔH than that of CaM, while CaM(3TnC) and CaM(4TnC) had similar binding thermodynamics as CaM. The dissociation rate constant for CaM/Orai-CMBD was determined to be 1.41 ± 0.08 s−1 by rapid kinetics. Stern-Volmer plots of Orai-CMBD Trp76 indicated that the residue is located in a very hydrophobic environment but becomes more solvent accessible when EF1 and EF2 were exchanged. Conclusions Using ANS dye to assess induced hydrophobicity showed that exchanging EFs for all Ca2+-bound chimeras impaired ANS fluorescence and/or binding affinity, consistent with general concepts about the inadequacy of hydrophobic exposure for chimeras. However, such ANS responses exhibited no correlation with the ability to interact with Orai-CMBD. Here, the model of 1:2 binding stoichiometry of CaM/Orai-CMBD established in solution supports the already published crystal structure

Leisure-Time Physical Activity and Characteristics of Social Network Support for Exercise Among Latinas

Purpose: To examine the association between characteristics of social support for exercise and moderate-to-vigorous leisure-time physical activity (LTPA) among Latinas. Design: This cross-sectional study used baseline data from a cluster randomized controlled trial. Setting: The study was conducted in 16 churches located in San Diego County. Participants: Participants (N = 436) were Latinas between 18 and 65 years old who did not self-report >150 minutes or did not exceed 250 minutes of moderate-to-vigorous PA per week measured by accelerometer. Measures: Latinas listed up to 6 individuals who had provided support for exercise within the past 6 months, including their gender, relationship with the respondent, types of support provided, and respondent’s satisfaction with support. Self-reported LTPA was dichotomized (none vs any). Analyses: We generated dyads between Latinas who named ≥1 supporter (n = 323) and each supporter they named (n = 569 dyads). Logistic regression analyses were conducted using generalized estimating equations to adjust for multiple observations per participant. Results: Having an exercise partner (odds ratio [OR]: 2.16; 95% confidence interval [CI]: 1.01-4.62), help with household duties (OR: 2.70; 95% CI: 1.35-3.38), being “very much” satisfied with support (OR: 2.33; 95% CI: 1.26-4.30), and naming >2 supporters (OR: 2.57; 95% CI: 1.06-6.25) was positively associated with LTPA. Conclusions: Findings suggest specific aspects of support for exercise that should be targeted in future interventions to promote LTPA

Did Covid-19 lockdown positively affect the urban environment and UN- Sustainable Development Goals?

Nigam, R., Tripathi, G., Priya, T., Luis, A. J., Vaz, E., Kumar, S., Shakya, A., Damásio, B., Kotha, M., & Yu, B. (Ed.) (2022). Did Covid-19 lockdown positively affect the urban environment and UN- Sustainable Development Goals? PLoS ONE, 17(9), 1-21. [e0274621]. https://doi.org/10.1371/journal.pone.0274621This work quantifies the impact of pre-, during- and post-lockdown periods of 2020 and 2019 imposed due to COVID-19, with regards to a set of satellite-based environmental parameters (greenness using Normalized Difference Vegetation and water indices, land surface temperature, night-time light, and energy consumption) in five alpha cities (Kuala Lumpur, Mexico, greater Mumbai, Sao Paulo, Toronto). We have inferenced our results with an extensive questionnaire-based survey of expert opinions about the environment-related UN Sustainable Development Goals (SDGs). Results showed considerable variation due to the lockdown on environment-related SDGs. The growth in the urban environmental variables during lockdown phase 2020 relative to a similar period in 2019 varied from 13.92% for Toronto to 13.76% for greater Mumbai to 21.55% for Kuala Lumpur; it dropped to −10.56% for Mexico and −1.23% for Sao Paulo city. The total lockdown was more effective in revitalizing the urban environment than partial lockdown. Our results also indicated that Greater Mumbai and Toronto, which were under a total lockdown, had observed positive influence on cumulative urban environment. While in other cities (Mexico City, Sao Paulo) where partial lockdown was implemented, cumulative lockdown effects were found to be in deficit for a similar period in 2019, mainly due to partial restrictions on transportation and shopping activities. The only exception was Kuala Lumpur which observed surplus growth while having partial lockdown because the restrictions were only partial during the festival of Ramadan. Cumulatively, COVID-19 lockdown has contributed significantly towards actions to reduce degradation of natural habitat (fulfilling SDG-15, target 15.5), increment in available water content in Sao Paulo urban area(SDG-6, target 6.6), reduction in NTL resulting in reducied per capita energy consumption (SDG–13, target 13.3).publishersversionpublishe

An Open Data and Citizen Science Approach to Building Resilience to Natural Hazards in a Data-Scarce Remote Mountainous Part of Nepal

The citizen science approach has gained momentum in recent years. It can enable both experts and citizen scientists to co-create new knowledge. Better understanding of local environmental, social, and geographical contexts can help in designing appropriate plans for sustainable development. However, a lack of geospatial data, especially in the context of developing countries, often precludes context-specific development planning. This study therefore tests an innovative approach of volunteer citizen science and an open mapping platform to build resilience to natural hazards in the remote mountainous parts of western Nepal. In this study, citizen scientists and mapping experts jointly mapped two districts of Nepal (Bajhang and Bajura) using the OpenStreetMap (OSM) platform. Remote mapping based on satellite imagery, capacity building, and mobilization of citizen scientists was performed to collect the data. These data were then uploaded to OSM and later retrieved in ArcGIS to produce a usable map that could be exploited as a reference resource for evidence-based decision-making. The collected data are freely accessible to community members as well as government and humanitarian actors, and can be used for development planning and risk reduction. By piloting in two communities of western Nepal, we found that using open data platforms for collecting and analyzing location-based data has a mutual benefit for researchers and communities. Such data could be vital in understanding the local landscape, environmental risk, and distribution of resources. Furthermore, they enable both researchers and local people to transfer technical knowledge, collect location-specific data, and use them for better decision-making