La igualdad de género en el proceso editorial de revistas de salud pública del continente americano

Despite an increase in the participation of women in scientific publications, a gender gap persists with a predominantly male authorship, especially in high-impact factor journals. Similarly, there is a lower proportion of women participating as peer reviewers or editors for journal publications.Revisión por paresCampus Lima Centr

Lambda-parameter of lattice QCD with the overlap-Dirac operator

We compute the ratio $\Lambda_L/\Lambda_{\bar{MS}}$ between the scale parameter $\Lambda_L$, associated with a lattice formulation of QCD using the overlap-Dirac operator, and $\Lambda_{\bar{MS}}$ of the $\bar{\rm MS}$ renormalization scheme. To this end, the necessary one-loop relation between the lattice coupling $g_0$ and the coupling renormalized in the $\bar{{\rm MS}}$ scheme is calculated, using the lattice background field technique.Comment: 11 pages, 2 figure

Chaos and stability in a two-parameter family of convex billiard tables

We study, by numerical simulations and semi-rigorous arguments, a two-parameter family of convex, two-dimensional billiard tables, generalizing the one-parameter class of oval billiards of Benettin--Strelcyn [Phys. Rev. A 17, 773 (1978)]. We observe interesting dynamical phenomena when the billiard tables are continuously deformed from the integrable circular billiard to different versions of completely-chaotic stadia. In particular, we conjecture that a new class of ergodic billiard tables is obtained in certain regions of the two-dimensional parameter space, when the billiards are close to skewed stadia. We provide heuristic arguments supporting this conjecture, and give numerical confirmation using the powerful method of Lyapunov-weighted dynamics.Comment: 19 pages, 13 figures. Submitted for publication. Supplementary video available at http://sistemas.fciencias.unam.mx/~dsanders

Rasgos biológicos y poblacionales del depredador ceraeochrysa sp. nr. cincta (México) (neuroptera: chrysopidae)

Ceraeochrysa sp. nr. cincta (Mexico) (Neuroptera: Chrysopidae) is a predator with cryptic larvae that attack diverse arthropod pests in fruit trees of Mexico. In order to contribute to facilitate the possible use of this beneficial insect in pest biological control, the objective of this study was to determine lifehistory traits and population parameters. We studied under controlled lab conditions three cohorts of 50 C. sp. nr. cincta specimens. The results showed that the species completed development, from egg to adult emergence, in 29 days, with 96% survivorship. The demographic statistics were: Ro = 95, T = 9 days, Td = 8 days and rm = 0.081 females per female per day. These traits are similar to some indicated for other reported chrysopid species; in contrast, C. sp. nr. cincta (Mexico) had a long preoviposition period, small proportion of ovipositing females and reduced egg fertility. Such reproductive characters were studied in a subsequent experiment, where females were maintained under different male ratios (1:0, 1:1, 1:2, 1:3 and 1:5). Except for the females that were kept without presence of males (1:0), those that were maintained temporarily with 1, 2, 3, and 5 males had short preoviposition period, as well as high values of ovipositing females, egg fertility and fecundity. The number of matings under the different proportions of female:male were not significantly different. The biological traits and demographic statistics results show the potential for mass-rearing and use of the predator in pest biological control in Mexico.Ceraeochrysa sp. nr. cincta (México) (Neuroptera: Chrysopidae) es un depredador con larvas crípticas que atacan diversos artrópodos plaga en frutales de México. Para contribuir al posible aprovechamiento de este insecto benéfico en el control biológico de plagas, esta investigación fue realizada con el objetivo de determinar sus rasgos biológicos y parámetros poblacionales. Los estudios se realizaron bajo condiciones controladas de laboratorio con tres cohortes de 50 individuos de C. sp. nr. cincta. Los resultados mostraron que el tiempo de desarrollo de huevo hasta la emergencia de adultos fue de 29 días, con una supervivencia general de 96%. Los estadísticos demográficos estimados, fueron: Ro = 95, T = 59 días, Td = 8 días y rm= 0.081 hijas/hembra/día. Estos rasgos son similares a los indicados para otras especies de Chrysopidae; en cambio, el porcentaje de hembras fecundadas y fertilidad de huevos fueron menores, y el periodo de preoviposición fue mayor. Estas características reproductivas fueron estudiadas en un experimento subsecuente, donde las hembras permanecieron con diferentes proporciones de machos (1:0, 1:1, 1:2, 1:3 y 1:5) en forma temporal. Excepto por la condición de hembras sin machos (1:0), cuando éstas se mantuvieron en forma temporal con 1, 2, 3 y 5 machos, mostraron un período de preoviposición más corto; también existieron valores altos de hembras en oviposición, fertilidad de huevos y fecundidad. El número de apareamientos bajo las diferentes proporciones de hembras:machos no fue significativamente diferente. Los resultados indican el potencial de C. sp. nr. cincta para ser producida masivamente para su aprovechamiento en el control biológico de plagas en México

Estudio del mecanismo de eliminación demagnesio de aleaciones Al-Si en estado líquido mediante inyección de minerales base sílice

RESUMEN Se empleó el método de inyección sumergida de polvos por medio de un gas de arrastre inerte (Ar) con el fin de eliminar el magnesio de la aleación Al-Si A380 a 750 °C. Los polvos inyectados al baño de metal fundido fueron zeolita mineral, arena sílice y mezclas de ambas. Las variables de respuesta medidas fueron el contenido de magnesio en el baño metálico respecto al tiempo de inyección y las mermas de metal al final de cada experimento. En el análisis de resultados, la mezcla sílice:zeolita 66:34 % e.p. obtuvo la mayor eficiencia, lográndose una disminución en el contenido de magnesio en el baño metálico de 1 a 0.0066 % e.p. Los productos de reacción se analizaron por difracción de rayos-X, microscopía electrónica de barrido y de transmisión. Los resultados de estos análisis y el empleo del paquete termodinámico FactSage, versión 6, permitieron justificar el mecanismo de reacción entre los minerales y el aluminio líquido. ABSTRAC In order to eliminate magnesium from an A 380 Al-Si alloy at 750°C, the submerged powder injection method, using an inert carrier gas (Ar), was applied. The injected powders in the liquid aluminum bath were zeolite, silica and mixtures of zeolite-silica minerals. For each experiment the response variables were: eliminated magnesium versus injection time and quantity of drosses produced. Chemical analysis by atomic absorption spectrometry showed that mixtures of silica-zeolite 66:34 wt% have the best results with regarding to the removal magnesium from 1 to 0.0066 wt%. During the elimination of magnesium complex stoichiometry compounds were formed due to the reactions among zeolite, water steam and liquid aluminum. These compounds were analyzed by XRD, SEM and TEM. The results obtained, along with using the FactSage 6 thermodynamic software, allowed to elucidate the reaction mechanism between the minerals used and liquid aluminum

Identification of virulence factors genes in Escherichia coli isolates from women with urinary tract infection

E coli isolates (108) from Mexican women, clinically diagnosed with urinary tract infection, were screened to identify virulence genes, phylogenetic groups, and antibiotic resistance. Isolates were identified by MicroScan4 system; additionally, the minimum inhibitory concentration (MIC) was assessed. The phylogenetic groups and 16 virulence genes encoding adhesins, toxins, siderophores, lipopolysaccharide (LPS), and invasins were identified by PCR. Phylogenetic groups distribution was as follows: B1 9.3%, A 30.6%, B2 55.6%, and D 4.6%. Virulence genes prevalence was ecp 98.1%, fimH 86.1%, traT 77.8%, sfa/focDE 74.1%, papC 62%, iutA 48.1%, fyuA 44.4%, focG 2.8%, sfaS 1.9%, hlyA 7.4%, cnf-1 6.5%, cdt-B 0.9%, cvaC 2.8%, ibeA 2.8%, and rfc 0.9%. Regarding antimicrobial resistance it was above 50% to ampicillin/sulbactam, ampicillin, piperacillin, trimethoprim/sulfamethoxazole, ciprofloxacin, and levofloxacin. Uropathogenic E. coli clustered mainly in the pathogenic phylogenetic group B2. The isolates showed a high presence of siderophores and adhesion genes and a low presence of genes encoding toxins. The high frequency of papC gene suggests that these isolates have the ability to colonize the kidneys. High resistance to drugs considered as first choice treatment such as trimethoprim/sulfamethoxazole and fluoroquinolones was consistently observed

Comparative fruit quality parameters of ‘Ninfa’ apricot (Prunus armeniaca L.) grafted on two different rootstocks in a newly established organic orchard

The fruit quality parameters of Prunus armeniaca L. cv ‘Ninfa’ grafted on ‘Myrobalan 29C’ (Prunus cerasifera Ehrh.) and ‘Real Fino’ apricot seedling (Prunus armeniaca L.) were analysed in an experimental orchard under organic management. The study was performed between 2010 and 2012 in the province of Seville (SW Spain). Colour, fruit and stone weights, firmness, soluble solid concentration, and acidity were measured for fruit quality evaluation. Trunk cross-sectional area, main branches, and fruit yield were also determined. In general, ‘Myrobalan 29C’ rootstock produced fruit slightly larger in size and with a bigger weight. By contrast, apricots on ‘Myrobalan 29C’ had less firmness and a lower solid soluble concentration than on ‘Real Fino’. There was little difference in the colour, acidity, and stone dry weights. Trees on ‘Real Fino’ had larger areas of trunk and branches but no significant differences were obtained in relation to fruit yields

No silver bullet for digital soil mapping: country-specific soil organic carbon estimates across Latin America.

Country-specific soil organic carbon (SOC) estimates are the baseline for the Global SOC Map of the Global Soil Partnership (GSOCmap-GSP). This endeavor is key to explaining the uncertainty of global SOC estimates but requires harmonizing heterogeneous datasets and building country-specific capacities for digital soil mapping (DSM).We identified country-specific predictors for SOC and tested the performance of five predictive algorithms for mapping SOC across Latin America. The algorithms included support vector machines (SVMs), random forest (RF), kernel-weighted nearest neighbors (KK), partial least squares regression (PL), and regression kriging based on stepwise multiple linear models (RK). Country-specific training data and SOC predictors (5 x 5 km pixel resolution) were obtained from ISRIC - World Soil Information. Temperature, soil type, vegetation indices, and topographic constraints were the best predictors for SOC, but country-specific predictors and their respective weights varied across Latin America. We compared a large diversity of country-specific datasets and models, and were able to explain SOC variability in a range between ~ 1 and ~ 60 %, with no universal predictive algorithm among countries. A regional (n = 11 268 SOC estimates) ensemble of these five algorithms was able to explain ~ 39% of SOC variability from repeated 5-fold cross-validation.We report a combined SOC stock of 77.8 +- 43.6 Pg (uncertainty represented by the full conditional response of independent model residuals) across Latin America. SOC stocks were higher in tropical forests (30 +- 16.5 Pg) and croplands (13 +- 8.1 Pg). Country-specific and regional ensembles revealed spatial discrepancies across geopolitical borders, higher elevations, and coastal plains, but provided similar regional stocks (77.8 +- 42.2 and 76.8 +- 45.1 Pg, respectively). These results are conservative compared to global estimates (e.g., SoilGrids250m 185.8 Pg, the Harmonized World Soil Database 138.4 Pg, or the GSOCmap-GSP 99.7 Pg). Countries with large area (i.e., Brazil, Bolivia, Mexico, Peru) and large spatial SOC heterogeneity had lower SOC stocks per unit area and larger uncertainty in their predictions. We highlight that expert opinion is needed to set boundary prediction limits to avoid unrealistically high modeling estimates. For maximizing explained variance while minimizing prediction bias, the selection of predictive algorithms for SOC mapping should consider density of available data and variability of country-specific environmental gradients. This study highlights the large degree of spatial uncertainty in SOC estimates across Latin America. We provide a framework for improving country-specific mapping efforts and reducing current discrepancy of global, regional, and country-specific SOC estimates

Living on the Edge: Assessing the Extinction Risk of Critically Endangered Bonelli’s Eagle in Italy

Background: The population of Bonelli’s eagle (Aquila fasciata) has declined drastically throughout its European range due to habitat degradation and unnatural elevated mortality. There are less than 1500 breeding pairs accounted for in Europe, and the species is currently catalogued as Critically Endangered in Italy, where the 22 territories of Sicily, represent nearly 95% of the entire Italian population. However, despite national and European conservation concerns, the species currently lacks a specific conservation plan, and no previous attempts to estimate the risk of extinction have been made. Methodology/Principal Findings: We incorporated the most updated demographic information available to assess the extinction risk of endangered Bonelli’s eagle in Italy through a Population Viability Analysis. Using perturbation analyses (sensitivity and elasticity), and a combination of demographic data obtained from an assortment of independent methods, we evaluated which demographic parameters have more influence on the population’s fate. We also simulated different scenarios to explore the effects of possible management actions. Our results showed that under the current conditions, Bonelli’s eagle is expected to become extinct in Italy in less than 50 years. Stand-alone juvenile mortality was the most critical demographic parameter with the strongest influence on population persistence with respect to other demographic parameters. Measures aimed at either decreasing juvenile mortality, adult mortality or decreasing both juvenile and adult mortality resulted in equivalent net positive effects on population persistence (population growth rate l.1). In contrast, changes aimed at increasing breeding success had limited positive effects on demographic trends. Conclusions/Significance: Our PVA provides essential information to direct the decision-making process and exposes gaps in our previous knowledge. To ensure the long-term persistence of the species in Italy, measures are urgently needed to decrease both adult mortality due to poaching and juvenile mortality due to nest plundering, the top ranking mortality causes.PLL is supported by a “Juan de la Cierva” postdoctoral grant of the Spanish Ministry of Economy and Competitiveness (reference JCI-2011–09588)