289 research outputs found
Rich do not rise early: Spatio-temporal patterns in the mobility networks of different socio-economic classes
We analyse the urban mobility in the cities of Medellín and Manizales (Colombia). Each city is represented by six mobility networks, each one encoding the origin-destination trips performed by a subset of the population corresponding to a particular socio-economic status. The nodes of each network are the different urban locations whereas links account for the existence of a trip between two different areas of the city. We study the main structural properties of these mobility networks by focusing on their spatio-temporal patterns. Our goal is to relate these patterns with the partition into six socio-economic compartments of these two societies. Our results show that spatial and temporal patterns vary across these socio-economic groups. In particular, the two datasets show that as wealth increases the early-morning activity is delayed, the midday peak becomes smoother and the spatial distribution of trips becomes more localized
Immunotherapies and Future Combination Strategies for Head and Neck Squamous Cell Carcinoma.
Head and neck squamous cell carcinoma (HNSCC) is often diagnosed at an advanced stage and has a dismal prognosis. Nearly 10 years after the approval of cetuximab, anti-PD1/PD-L1 checkpoint inhibitors are the first drugs that have shown any survival benefit for the treatment on platinum-refractory recurrent/metastatic (R/M) HNSCC. Furthermore, checkpoint inhibitors are better tolerated than chemotherapy. The state of the art in the treatment of R/M HNSCC is changing, thanks to improved results for checkpoint inhibitors. Results for these treatments are also awaited in curative settings and for locally advanced HNSCC. Unfortunately, the response rate of immunotherapy is low. Therefore, the identification of predictive biomarkers of response and resistance to anti-PD1/PD-L1 is a key point for better selecting patients that would benefit the most from immunotherapy. Furthermore, the combination of checkpoint inhibitors with various agents is being currently evaluated to improve the response rate, prolong response duration, and even increase the chances for a cure. In this review, we summarize the most important results regarding immune targeting agents for HNSCC, predictive biomarkers for resistance to immune therapies, and future perspectives
Cash Transfers, Young Women’s Economic Well-Being, and HIV Risk: Evidence from HPTN 068
Despite the large interest in economic interventions to reduce HIV risk, little research has been done to show whether there are economic gains of these interventions for younger women and what intermediary role economic resources play in changing participants’ sexual behavior. This paper contributes to this gap by examining the impacts of a conditional cash transfer (CCT) for young women in South Africa on young women’s economic resources and the extent to which they play a role in young women’s health and behavior. We used data from HIV Prevention Trials Network 068 study, which provided transfers to young women (in addition to their parents) conditional on the young woman attending at least 80% of school days in the previous month. We found that the CCT increased young women’s economic wellbeing in terms of having savings, spending money, being unindebted, and food secure. We also investigated heterogeneous effects of the program by household economic status at baseline because the program was not specifically poverty targeted and found that the results were driven by young women from the poorest families. From these results, we examined heterogeneity by baseline poverty for other outcomes related to HIV risk including sexual behavior and psychosocial well-being. We found psychosocial well-being benefits in young women from the poorest families and that economic wellbeing gains explained much these impacts
Detención de Spongospora subterranea (Walleroth) Lagerheim f. sp subterranea mediante secuencias específicas de ADN en suelos y tubérculos para semilla de papa.
Trabajo de investigación, a través del cual se evaluó la técnica de PCR (Polimerase Chain Reaction), a fin de implementar dicha metodología no solo como una técnica útil para la detección rápida en suelo, sino también como una herramienta para prevenir la dispersión del microorganismo hacia suelos declarados libres de éste, así como para el control de calidad de semilla de papa libre del patógeno. La metodología investigativa incluyó: obtención de muestras infectadas con S. subterranea, a partir de material vegetal con síntomas y signos típicos de la roña polvosa y de suelos cultivados con papa donde se manifestó el patógeno, de muestras colectadas y enviadas por el Programa de Producción de Semilla Certificad del ICA seccional Cundinamarca y por el Laboratorio de Diagnóstico Fitosanitario de Pasto, detección macroscópica y microscópica en tejido vegetal infectado, con descripción microscópica de las lesiones típicas de la enfermedad tanto en semillas de papa como en raíces infectadas, propagación de S. subterranea bajo condiciones de invernadero, empleando como inóculo 50 gramos de mezcla de suelo infestado proveniente de los departamentos de Cundinamarca y Nariño, extracción de ADN a partir del suelo y tejido vegetal infectado, utilizando el protocolo de Aponte (Aponte 1998), seguido de columnas de purificación GFX Genomic Columns (Amersham Farmacia) y protocolo de extracción de ADN mediante el uso de estuche comercial Ultra Clean Soil DNA (Mo Bio Laboratories), y prueba de Reacción en Cadena de Polimerasa a partir de ADN de S. subterranea, usando los cebadores Spo 1-2, Spo 8-9 y Sps 1-
Boost operators in Coulomb-gauge QCD: the pion form factor and Fock expansions in phi radiative decays
In this article we rederive the Boost operators in Coulomb-Gauge Yang-Mills
theory employing the path-integral formalism and write down the complete
operators for QCD. We immediately apply them to note that what are usually
called the pion square, quartic... charge radii, defined from derivatives of
the pion form factor at zero squared momentum transfer, are completely blurred
out by relativistic and interaction corrections, so that it is not clear at all
how to interpret these quantities in terms of the pion charge distribution. The
form factor therefore measures matrix elements of powers of the QCD boost and
Moeller operators, weighted by the charge density in the target's rest frame.
In addition we remark that the decomposition of the eta' wavefunction in
quarkonium, gluonium, ... components attempted by the KLOE collaboration
combining data from phi radiative decays, requires corrections due to the
velocity of the final state meson recoiling against a photon. This will be
especially important if such decompositions are to be attempted with data from
J/psi decays.Comment: 14 pages, 4 figure
Vector meson production and nucleon resonance analysis in a coupled-channel approach for energies m_N < sqrt(s) < 2 GeV II: photon-induced results
We present a nucleon resonance analysis by simultaneously considering all
pion- and photon-induced experimental data on the final states gamma N, pi N, 2
pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass
up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the
resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), and D_{13}(1950). The
omega N production mechanism is dominated by large P_{11}(1710) and
P_{13}(1900) contributions. In this second part we present the results on the
photoproduction reactions and the electromagnetic properties of the resonances.
The inclusion of all important final states up to sqrt(s) = 2 GeV allows for
estimates on the importance of the individual states for the GDH sum rule.Comment: 41 pages, 26 figures, discussion extended, typos corrected,
references updated, to appear in Phys. Rev.
Associations of Father and Adult Male Presence with First Pregnancy and HIV Infection: Longitudinal Evidence from Adolescent Girls and Young Women in Rural South Africa (HPTN 068)
This study, a secondary analysis of the HPTN 068 randomized control trial, aimed to quantify the association of father and male presence with HIV incidence and first pregnancy among 2533 school-going adolescent girls and young women (AGYW) in rural South Africa participating in the trial between March 2011 and April 2017. Participants’ ages ranged from 13–20 years at study enrollment and 17–25 at the post-intervention visit. HIV and pregnancy incidence rates were calculated for each level of the exposure variables using Poisson regression, adjusted for age using restricted quadratic spline variables, and, in the case of pregnancy, also adjusted for whether the household received a social grant. Our study found that AGYW whose fathers were deceased and adult males were absent from the household were most at risk for incidence of first pregnancy and HIV (pregnancy: aIRR = 1.30, Wald 95% CI 1.05, 1.61, Wald chi-square p = 0.016; HIV: aIRR = 1.27, Wald 95% CI 0.84, 1.91, Wald chi-square p = 0.263) as compared to AGYW whose biological fathers resided with them. For AGYW whose fathers were deceased, having other adult males present as household members seemed to attenuate the incidence (pregnancy: aIRR = 0.92, Wald 95% CI 0.74, 1.15, Wald chi-square p = 0.462; HIV: aIRR = 0.90, Wald 95% CI 0.58, 1.39, Wald chi-square p = 0.623) such that it was similar, and therefore not statistically significantly different, to AGYW whose fathers were present in the household
Unifying inflation with dark energy in modified F(R) Horava-Lifshitz gravity
We study FRW cosmology for a non-linear modified F(R) Horava-Lifshitz gravity
which has a viable convenient counterpart. A unified description of early-time
inflation and late-time acceleration is possible in this theory, but the
cosmological dynamic details are generically different from the ones of the
convenient viable F(R) model. Remarkably, for some specific choice of
parameters they do coincide. The emergence of finite-time future singularities
is investigated in detail. It is shown that these singularities can be cured by
adding an extra, higher-derivative term, which turns out to be qualitatively
different when compared with the corresponding one of the convenient F(R)
theory.Comment: LaTeX 12 pages, typos are correcte
Field Measurements of Terrestrial and Martian Dust Devils
Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types
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