On the fraction of dark matter in charged massive particles (CHAMPs)

From various cosmological, astrophysical and terrestrial requirements, we derive conservative upper bounds on the present-day fraction of the mass of the Galactic dark matter (DM) halo in charged massive particles (CHAMPs). If dark matter particles are neutral but decay lately into CHAMPs, the lack of detection of heavy hydrogen in sea water and the vertical pressure equilibrium in the Galactic disc turn out to put the most stringent bounds. Adopting very conservative assumptions about the recoiling velocity of CHAMPs in the decay and on the decay energy deposited in baryonic gas, we find that the lifetime for decaying neutral DM must be > (0.9-3.4)x 10^3 Gyr. Even assuming the gyroradii of CHAMPs in the Galactic magnetic field are too small for halo CHAMPs to reach Earth, the present-day fraction of the mass of the Galactic halo in CHAMPs should be < (0.4-1.4)x 10^{-2}. We show that redistributing the DM through the coupling between CHAMPs and the ubiquitous magnetic fields cannot be a solution to the cuspy halo problem in dwarf galaxies.Comment: 21 pages, 2 figures. To appear in JCA

New Perspectives in the Development of the Artificial Sport Trainer

ABSTRACT: The rapid development of computer science and telecommunications has brought new ways and practices to sport training. The artificial sport trainer, founded on computational intelligence algorithms, has gained momentum in the last years. However, artificial sport trainer usually suffers from a lack of automatisation in realization and control phases of the training. In this study, the Digital Twin is proposed as a framework for helping athletes, during realization of training sessions, to make the proper decisions in situations they encounter. The digital twin for artificial sport trainer is based on the cognitive model of humans. This concept has been applied to cycling, where a version of the system on a Raspberry Pi already exists. The results of porting the digital twin on the mentioned platform shows promising potential for its extension to other sport disciplines.Akemi Galvez and Andres Iglesias have received funding from the project PDE-GIR of the European Union’s Horizon 2020 research and innovation programme under the Marie SklodowskaCurie grant agreement no. 778035, and from the project TIN2017-89275-R funded by MCIN/AEI/10.13039/501100011033/FEDER “Una manera de hacer Europa”

Biomass and nutrient dynamics associated with slash fires in neotropical dry forests

Unprecedented rates of deforestation and biomass burning in tropical dry forests are dramatically influencing biogeochemical cycles, resulting in resource depletion, declines in biodiversity, and atmospheric pollution. We quantified the effects of defores- tation and varying levels of slash-fire severity on nutrient losses and redistribution in a second-growth tropical dry forest ("Caatinga") near Serra Talhada, Pernambuco, Brazil. Total aboveground biomass prior to burning was 74 Mg/ha. Nitrogen and phosphorus concentrations were highest in litter, leaves attached to slash, and fine wood debris (<0.64 cm diameter). While these components comprised only 30% of the prefire aboveground biomass, they accounted for -60% of the aboveground pools of N and P. Three experi- mental fires were conducted during the 1989 burning season. In these treatments con- sumption was 78, 88, and 95% of the total aboveground biomass. As much as 96% of the prefire aboveground N and C pools and 56% of the prefire aboveground P pool was lost during combustion processes. Nitrogen losses exceeded 500 kg/ha and P losses exceeded 20 kg/ha in the fires of the greatest severity. With increasing fire severity, the concentrations of N and P in ash decreased while the concentration of Ca increased. This indicates greater amounts of these nutrients were volatilized (i.e., greater ecosystem losses occurred) with increasing fire severity. Following fire, up to 47% of the residual aboveground N and 84% of the residual aboveground P were in the form of ash, which was quickly lost from the site via wind erosion. Fires appeared to have a minor immediate effect on total N, C, or P in the soils. However, soils in forests with no history of cultivation had significantly higher concentrations of C and P than second-growth forests. Based upon the measured losses of nutrients from these single slash-burning events, it would likely require a century or more of fallow for reaccumulation to occur. However, current fallow periods in this region are 15 yr or less

Stakeholder management and project management office: effect on project results

Managing stakeholders is relevant for project management, as they affect project results. Likewise, the support of a Project Management Office (PMO) improves these results. This study analyzes the positive influence of stakeholder management on project results, specifically on the likelihood of concluding projects within the predicted time and cost, together with the moderating effect of PMOs. A conceptual model was validated through logistic regression, with data collected through a survey responded by 216 experienced professionals studying in graduate programs on project management. Findings indicate that stakeholder management improves project results in terms of time and cost and confirm that PMO enhances the influence of stakeholder management on these results. As its contribution, the study reinforces stakeholder management and PMO as key elements for successful project management. Sampling was sufficient for research replicability but restricted to professionals of project management living in Peru. Thus, future studies could target a broader population.La gesti?n de stakeholders es relevante para la gesti?n de proyectos, ya que afectan los resultados del proyecto. Asimismo, el apoyo de una Oficina de Gesti?n de Proyectos (PMO) tambi?n mejora estos resultados. Este estudio tiene como objetivo analizar la influencia positiva de la gesti?n de stakeholders en los resultados del proyecto, espec?ficamente en la probabilidad de concluir los proyectos en tiempo y costo, junto con el efecto moderador de la PMO. Se valid? un modelo conceptual mediante regresi?n log?stica, con 216 encuestados. Los hallazgos indican que la gesti?n de stakeholders mejora los resultados del proyecto, en t?rminos de tiempo y costo, y confirman que la PMO mejora la influencia de la gesti?n de stakeholders en estos resultados. Como contribuci?n, el estudio refuerza la gesti?n de stakeholders y PMO como elementos clave para una exitosa gesti?n de proyectos. Asimismo, el muestreo fue suficiente para la replicabilidad de la investigaci?n, restringida a los profesionales del proyecto que viven en Per?. Por lo tanto, los estudios futuros podr?an apuntar a una poblaci?n m?s amplia

Beyond complex Langevin equations II: a positive representation of Feynman path integrals directly in the Minkowski time

Recently found positive representation for an arbitrary complex, gaussian weight is used to construct a statistical formulation of gaussian path integrals directly in the Minkowski time. The positivity of Minkowski weights is achieved by doubling the number of real variables. The continuum limit of the new representation exists only if some of the additional couplings tend to infinity and are tuned in a specific way. The construction is then successfully applied to three quantum mechanical examples including a particle in a constant magnetic field -- a simplest prototype of a Wilson line. Further generalizations are shortly discussed and an intriguing interpretation of new variables is alluded to.Comment: 16 pages, 2 figures, references adde

Faces da ilegalidade em Bogotá

Os bairros de Santa Inés e Santa Fe, no centro histórico de Bogotá, estão entre os mais perigosos da capital colombiana e são classificados pelo governo distrital como Zonas Vermelhas, Críticas ou de Alto Impacto. Neste artigo, são exploradas, a partir de uma perspectiva etnográfica, as diversas relações entre legalidade e ilegalidade nessas regiões de medo e perigo, cuja degradação física e moral é atribuída a certas pessoas estigmatizadas. São descritas as regulações informais internas ou máximas da rua, como no dar papaya ["não dar mole"], e sua coexistência com práticas de "limpeza social", que refletem intolerância e moralismo no convívio com a diferença. Recentemente, os projetos de renovação urbana, que fazem parte dos planos de recuperação do Centro, buscam intervir nesses setores de delinquência, prostituição e atividades ilegais com o fim de erradicar a violência e empreender futuros megaprojetos residenciais e comerciais de revalorização imobiliária.The Santa Inés and Santa Fe districts in Bogotá's historical centre are among the Colombian capital's most dangerous, classified by the local government as Red, Critical or High Impact Zones. This article provides an ethnographic exploration of the complex relations between legality and illegality in these regions associated with fear and danger, whose physical and moral decline are attributed to certain stigmatized groups of people. It describes the informal internal regulations or street maxims, such as no dar papaya ['don't be soft'], and their coexistence with 'social cleansing' practices that reflect intolerance and moralism in the face of difference. Recently the urban reform projects, which form part of the plans for recuperating the Centre, have tried to intervene in these sectors of crime, prostitution and illegal activities in order to eradicate violence and pave the way for future residential and commercial megaprojects designed to improve the real estate value of urban areas

Gerenciamento de stakeholders e escritório de gerenciamento de projetos: Efeito nos resultados

Uma vez que stakeholders de projetos afetam seus resultados, o gerenciamento desses atores deve ser considerado uma atividade relevante no gerenciamento de projetos. Somado a essa evidência, este estudo reconhece que os resultados de projetos podem ser incrementados quando há o apoio de um Escritório de Gerenciamento de Projetos (EGP). Assim, busca-se analisar a influência positiva do gerenciamento de stakeholders nos resultados dos projetos, especificamente na probabilidade de sua conclusão dentro de prazos e custos previstos, considerando o efeito moderador do apoio de EGPs. Para isso, o estudo apresenta um modelo conceitual validado por regressão logarítmica, usando dados coletados em pesquisa do tipo survey respondida por 216 professionais experientes da área de gerenciamento de projetos e que estudam o tema em cursos de pós-graduação. Os resultados indicam que o gerenciamento de stakeholders melhora os resultados de projetos e confirmam que o EGP aprimora a influência desse tipo de gerenciamento nos resultados. Como contribuição, a pesquisa reforça o gerenciamento de stakeholders e o apoio de EGPs como elementos-chave para o sucesso no gerenciamento de projetos. A amostragem foi suficiente para a replicabilidade da pesquisa, contudo restringiu-se a profissionais que vivem no Peru. Portanto, estudos futuros podem buscar alcançar uma população mais ampla.

The Strongly Coupled 't Hooft Model on the Lattice

We study the strong coupling limit of the one-flavor and two-flavor massless 't Hooft models, $large-{\cal N}_c$-color $QCD_2$, on a lattice. We use staggered fermions and the Hamiltonian approach to lattice gauge theories. We show that the one-flavor model is effectively described by the antiferromagnetic Ising model, whose ground state is the vacuum of the gauge model in the infinite coupling limit; expanding around this ground state we derive a strong coupling expansion and compute the lowest lying hadron masses as well as the chiral condensate of the gauge theory. Our lattice computation well reproduces the results of the continuum theory. Baryons are massless in the infinite coupling limit; they acquire a mass already at the second order in the strong coupling expansion in agreement with the Witten argument that baryons are the $QCD$ solitons. The spectrum and chiral condensate of the two-flavor model are effectively described in terms of observables of the quantum antiferromagnetic Heisenberg model. We explicitly write the lowest lying hadron masses and chiral condensate in terms of spin-spin correlators on the ground state of the spin model. We show that the planar limit (${\cal N}_c\longrightarrow \infty$) of the gauge model corresponds to the large spin limit ($S\longrightarrow \infty$) of the antiferromagnet and compute the hadron mass spectrum in this limit finding that, also in this model, the pattern of chiral symmetry breaking of the continuum theory is well reproduced on the lattice.Comment: LaTex, 25 pages, no figure

Direct-acting antivirals are effective and safe in HCV/HIV-coinfected liver transplant recipients who experience recurrence of hepatitis C: A prospective nationwide cohort study.

Direct-acting antivirals have proved to be highly efficacious and safe in monoinfected liver transplant (LT) recipients who experience recurrence of hepatitis C virus (HCV) infection. However, there is a lack of data on effectiveness and tolerability of these regimens in HCV/HIV-coinfected patients who experience recurrence of HCV infection after LT. In this prospective, multicenter cohort study, the outcomes of 47 HCV/HIV-coinfected LT patients who received DAA therapy (with or without ribavirin [RBV]) were compared with those of a matched cohort of 148 HCV-monoinfected LT recipients who received similar treatment. Baseline characteristics were similar in both groups. HCV/HIV-coinfected patients had a median (IQR) CD4 T-cell count of 366 (256-467) cells/µL. HIV-RNA was <50 copies/mL in 96% of patients. The DAA regimens administered were SOF + LDV ± RBV (34%), SOF + SMV ± RBV (31%), SOF + DCV ± RBV (27%), SMV + DCV ± RBV (5%), and 3D (3%), with no differences between the groups. Treatment was well tolerated in both groups. Rates of SVR (negative serum HCV-RNA at 12 weeks after the end of treatment) were high and similar for coinfected and monoinfected patients (95% and 94%, respectively; P = .239). Albeit not significant, a trend toward lower SVR rates among patients with advanced fibrosis (P = .093) and genotype 4 (P = .088) was observed. In conclusion, interferon-free regimens with DAAs for post-LT recurrence of HCV infection in HIV-infected individuals were highly effective and well tolerated, with results comparable to those of HCV-monoinfected patients