Una nueva especie de alacrán del género Centruroides Marx (1890) (Scorpiones, Buthidae) de la depresión del Balsas, México

Se describe una nueva especie del género Centruroides Marx de la Depresión del Balsas en los Estados de Guerrero, Michoacán y México, en elevaciones que van de los 400 a los 1500 msnm. Esta especies se caracteriza por tener ocho hileras de dentículos en los dedos de la quela del pedipalpo y corresponde, dentro del género, a la sección de alacranes rayados, en la cual se le ha confundido con Centruroides limpidus limpidus Karsch y con Centruroides limpidus tecomanus Hoffmann. Las diferencias se observan en morfometría y patrón de coloración. Esta nueva especie es simpátrica con C. limpidus limpidus en la parte Este de su rango de distribución en el Estado de Michoacán y con C. infamatus infamatus Pocock en la Sierra de Coalcomán y regiones adyacentes en la parte Norte del Estado. Se registra también en una localidad en el Estado de Guerrero y en una localidad en el Estado de México.A new species of scorpion of the genus Centruroides Marx is described. It occurs in the Balsas River Depression in the states of Guerrero and Michoacan, Mexico, at elevations ranging from 400 m to 1500 m above sea level. It has eight rows of denticles on the pedipalp fingers, and belongs to the stripped section of the genus, where it had been previously confused with Centruroides limpidus limpidus Karsch and with Centruroides limpidus tecomanus Hoffmann. It differs in morphometrics and color pattern. The new species is sympatric with C. limpidus limpidus in the eastern part of its range in the state of Michoacan, and with Centruroides infamatus Pocock in the Sierra de Coalcoman and adjacent regions in the northern part of the state. One locality in Guerrero State and another one in Mexico State are recorded too

Diversidad en comunidades de diatomeas epilíticas con relación a los parámetros fisicoquímicos en la cabecera del río Zinapécuaro, México

Background. The Zinapécuaro River basin has a high level of pollution coming from different economic activities that take place in the area, which have caused noticeable environmental damage. Unfortunately, there are no studies of the water quality of this river and thus we have no information regarding what current pollutants are present or their emitting sources. Goals. We studied the epilithic diatom community of the headwaters of the Zinapécuaro River, Michoacán, Mexico. Methods. Samples were collected at four stages during a one-year period. Results. Seventy species pertaining to the classes Coscinodiscophyceae, Fragilariophyceae, and Bacillariophyceae were identified. The latter had 62 taxa. The species found at all of the sampling sites were Achnanthidium exiguum, A. minutissimum, Encyonema silesiacum, Eolimna subminuscula, Frustulia latita, F. neomundana, Gomphonema lagenula, Navicula rhynchocephala, Nitzschia clausii, N. palea, Planothidium frequentissimum, P. lanceolatum, and Rhopalodia brebisonii. Among the species found at the sites, the ones with the highest degree of eutrophication are Navicula germainii, N. recens, N. rhynchocephala, Nitzchia clausii, N. palea, N. inconspicua, and Planothidium lanceolatum. Conclusions. Using nonparametric estimators, we foundthat observed species richness represented 80.5 to 89.7% of the expected richness. Rarefaction analysis indicated that the sampling effort was enough to represent the species richness in the study area and at the selected sites, except at a spring and at the Yerbabuena River during the rainy season (2013), and the Yerbabuena spring during the dry season (2013), where a greater number of samples would be needed. The greatest diversity, estimated with the Shannon-Wiener index, was found at Las Orquídeas during the rainy season of 2013. Seasonal analysis using ANOSIM showed no statistically significant differences (p >0.05), whereas Bray-Curtis similarity values did show statistically significant differences. Spatial and temporal distribution differences were associated with the differences in depth, nitrites, ammonium, pH, and total water hardness.Antecedentes. La cuenca del río Zinapécuaro presenta un alto grado de contaminación proveniente de diversas actividades económicas que se desarrollan en la zona, situación que ha generado un marcado deterioro ambiental. Desafortunadamente no existen estudios de la calidad del agua en este río y se desconoce el tipo de contaminantes presentes y las fuentes emisoras. Objetivos. Estudiar la comunidad de diatomeas epilíticas de la cabecera del río Zinapécuaro, Michoacán, México. Métodos. La recolecta se llevó a cabo durante un ciclo anual y se realizaron cuatro muestreos. Resultados. Fueron identificadas 70 especies pertenecientes a las clases Coscinodiscophyceae, Fragilariophyceae y Bacillariophyceae, esta última fue representada con 62 taxones. Las especies comunes en todos los sitios fueron Achnanthidium exiguum, A. minutissimum, Encyonema silesiacum, Eolimna subminuscula, Frustulia latita, F. neomundana, Gomphonema lagenula, Navicula rhynchocephala, Nitzschia clausii, N. palea, Planothidium frequentissimum, P. lanceolatum y Rhopalodia brebisonii. Las especies presentes en sitios con mayor grado de eutrofización fueron Navicula germainii, N. recens, N. rhynchocephala, Nitzchia clausii, N. palea, N. inconspicua y Planothidium lanceolatum. Conclusiones. Mediante estimadores no paramétricos se encontró que la riqueza específica obtenida fue de 80.5 a 89.7% de la riqueza esperada. El análisis de rarefacción indicó que el esfuerzo de muestreo para representar la riqueza del área de estudio y los sitios seleccionados fue suficiente, excepto para el manantial y el río Yerbabuena en la época de lluvias (2013) y el manantial de la Yerbabuena en la época de estiaje (2013), en los que se requeriría un tamaño de muestra más grande. La mayor diversidad, estimada con el índice Shannon-Wiener, se presentó en Las Orquídeas (época de lluvias 2013). El análisis por temporadas mediante ANOSIM no mostró diferencia estadística significativa en similitud (p >0.05) entre ellas; mientras que para sitios/temporadas sí hubo diferencias en los valores de similitud de Bray-Curtis. Las diferencias de distribución a nivel temporal y espacial se asociaron a diferencias en profundidad, nitritos, amonio, pH y dureza total

Una nueva especie de alacrán del género Centruroides Marx (Scorpiones: Buthidae) de la costa Noroeste de México

Centruroides baldazoi sp. nov. is described based on a coastal population of scorpions from the state of Sinaloa, Northwestern Mexico. The new species belongs to the "striped" group of scorpions (sensu Hoffmann, 1932) and the subgroup "infamatus" according to Ponce-Saavedra and Francke (2019). Morphological comparison is made with Centruroides suffusus, a species of the same group that is registered for the state of Sinaloa; with C. infamatus species that gives its name to the subgroup and that has historical records in Sinaloa, and with C. ornatus which its general appearance could be confused with the new species. With this addition the species of the genus Centruroides from Sinaloa now comprises: C. edwardsii, and C. noxius of the group of "non-striped" scorpions in addition to C. infamatus, C. pallidiceps, C. suffusus and the new species of the group of "striped" scorpions. The new species share habitat with Thorellius wixarica which is a new record for the state of Sinaloa, and Paravaejovis aff. spinigerus, both species of the family Vaejovidae.Se describe Centruroides baldazoi sp. nov. con base en una población de alacranes de la costa del estado de Sinaloa, México. La nueva especie se ubica en los alacranes “rayados” (sensu Hoffmann, 1932) y el subgrupo “infamatus” de acuerdo con Ponce-Saavedra y Francke (2019). Se hace la comparación morfológica con Centruroides suffusus, especie del mismo grupo que se encuentra registrado para el estado de Sinaloa; con C. infamatus especie que le da nombre al subgrupo y que tiene registros históricos en Sinaloa y con C. ornatus cuya apariencia general pudiera confundirse con la especie nueva. Con esta adición la lista de especies del género Centruroides para Sinaloa queda formada por: C. edwardsii, y C. noxius del grupo de alacranes “no rayados” además de C. infamatus, C. pallidiceps, C. suffusus y la nueva especie del grupo de alacranes “rayados”. La nueva especie comparte hábitat con Thorellius wixarica, que representa un nuevo registro para el estado de Sinaloa y Paravaejovis aff. spinigerus, ambas especies de la familia Vaejovidae

Diversidad de especies de Blacus (Hymenoptera: Braconidae, Blacinae) en dos ecosistemas forestales de Michoacán, México

Este estudio estimó la diversidad de avispas del género Blacus Nees (Braconidae, Blacinae) en dos ecosistemas forestales del noreste de Michoacán, en el Eje Neovolcánico Transversal: Parque Nacional Cerro de Garnica (PN C-Garnica) y Zona Protectora Forestal Los Azufres (ZPF Los Azufres). Se elaboró un mapa de cobertura vegetal con imágenes satelitales de estos ecosistemas forestales. La captura de especímenes se realizó mensualmente desde marzo 2008 hasta febrero 2010 con la ayuda de platos-trampa de color amarillo. Se capturó un total de 172 especímenes de 17 especies del género Blacus, de los cuales 84.3% provinieron del PN C-Garnica (13 especies) y 15.7% de la ZPF Los Azufres (10 especies). El porcentaje de similitud indicó una composición de especies diferente entre las dos áreas estudiadas (índice de Jaccard = 0.35). En el PN C-Garnica se capturaron significativamente más especímenes por mes que en la ZPF Los Azufres (12.1 ± 4.0 vs 2.3 ± 1.20). De acuerdo con el índice de Shannon-Wiener, la diversidad fue similar en ambas áreas estudiadas (2.1 vs 1.9). Los estimadores de riqueza Chao 2 y Jackknife 2 indicaron que en ambas áreas se capturó ~60% de las especies esperadas. Se concluye que el PN C-Garnica y la ZPF Los Azufres mantienen una alta diversidad de especies de Blacus. Las mayores abundancias, así como la mayor riqueza de especies se encontraron en el PN C-Garnica, la cual es una zona con mayor grado de perturbación.In this study, the diversity of wasps of the Blacus Nees (Braconidae, Blacinae) genus were estimated in two forest ecosystems in the northeastern part of Michoacán, in the Trans-Mexican Volcanic Belt: Cerro de Garnica National Park (C-Garnica NP) and Los Azufres Protected Forest Area (Los Azufres PFA). A vegetation cover map based on satellite images of these forest ecosystems was prepared. The specimens collecting was performed monthly from March 2008 until February 2010 with the help of yellow pan traps. A total of 172 specimens of 17 species of the genus Blacus were collected, of which 84.3% were from C-Garnica NP (13 species) and 15.7% from Los Azufres PFA (10 species). Percentage of similarity (Jaccard´s index = 0.35) was relatively low, indicating a different composition between both forest ecosystems. Significantly more specimens were monthly captured in C-Garnica NP than in Los Azufres PFA (12.1 ± 4.0 vs 2.3 ± 1.20). According to the Shannon-Wiener index, the diversity was similar in both studied areas (2.1 vs 1.9). Chao 2 and Jackknife 2 estimators indicated that ~60% of the expected species were captured in both areas. One concludes that C-Garnica NP and Los Azufres PFA maintain a high species diversity of Blacus. The greatest abundance, as well as the greatest species richness were found in the C-Garnica NP, which is an area with a higher degree of disturbance

Influence of color and height of pan traps to capture braconids (Hymenoptera: Braconidae)

The aim of this study was to determine the effectiveness of capturing braconids (Hymenoptera: Braconidae) on yellow, blue, cream, and green pan traps at two heights (0 and 90 cm) for a period of four weeks in the Natural Protected Area “Cerro Punhuato”, (Morelia, Michoacan, Mexico). The reflectance of each color was measured with a field analytical spectrophotometer. One hundred four (104) specimens, belonging to 14 subfamilies and 28 genera, were collected. Yellow and green pan traps caught the largest number of specimens and the greatest diversity of genera, showing 56.5 % similarity, as estimated with the Bray-Curtis index. Yellow pan traps installed at ground level exceeded the capture in green pan traps. The level of reflectance of the green and yellow pan traps was in the range from 360 to 530 nm, possibly indicating that this is the wavelength range in which braconids are attracted to both color

Development and internal validation of a multifactorial risk prediction model for gallbladder cancer in a high-incidence country

Since 2006, Chile has been implementing a gallbladder cancer (GBC) prevention program based on prophylactic cholecystectomy for gallstone patients aged 35 to 49 years. The effectiveness of this prevention program has not yet been comprehensively evaluated. We conducted a retrospective study of 473 Chilean GBC patients and 2137 population-based controls to develop and internally validate three GBC risk prediction models. The Baseline Model accounted for gallstones while adjusting for sex and birth year. Enhanced Model I also included the non-genetic risk factors: body mass index, educational level, Mapuche surnames, number of children and family history of GBC. Enhanced Model II further included Mapuche ancestry and the genotype for rs17209837. Multiple Cox regression was applied to assess the predictive performance, quantified by the area under the precision-recall curve (AUC-PRC) and the number of cholecystectomies needed (NCN) to prevent one case of GBC at age 70 years. The AUC-PRC for the Baseline Model (0.44%, 95%CI 0.42-0.46) increased by 0.22 (95%CI 0.15-0.29) when non-genetic factors were included, and by 0.25 (95%CI 0.20-0.30) when incorporating non-genetic and genetic factors. The overall NCN for Chileans with gallstones (115, 95%CI 104-131) decreased to 92 (95%CI 60-128) for Chileans with a higher risk than the median according to Enhanced Model I, and to 80 (95%CI 59-110) according to Enhanced Model II. In conclusion, age, sex and gallstones are strong risk factors for GBC, but consideration of other non-genetic factors and individual genotype data improves risk prediction and may optimize allocation of financial resources and surgical capacity.Fil: Boekstegers, Felix. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Scherer, Dominique. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Barahona Ponce, Carol. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Marcelain, Katherine. Universidad de Chile; ChileFil: Gárate Calderón, Valentina. Universidad de Chile; ChileFil: Waldenberger, Melanie. No especifíca;Fil: Morales, Erik. Universidad Católica de Maule; ChileFil: Rojas, Armando. Universidad Católica de Maule; ChileFil: Munoz, César. Universidad Católica de Maule; ChileFil: Retamales, Javier. Instituto Nacional del Cáncer; ChileFil: de Toro, Gonzalo. Universidad Austral de Chile; ChileFil: Barajas, Olga. Universidad de Chile; ChileFil: Rivera, María Teresa. Hospital del Salvador; ChileFil: Cortés, Analía. Hospital del Salvador; ChileFil: Loader, Denisse. Hospital Padre Hurtado; ChileFil: Saavedra, Javiera. Hospital Padre Hurtado; ChileFil: Gutiérrez, Lorena. Hospital San Juan de Dios; ChileFil: Ortega, Alejandro. Hospital Regional; ChileFil: Bertrán, Maria Enriqueta. Hospital Base de Valdivia; ChileFil: Bartolotti, Leonardo. Hospital Base de Valdivia; ChileFil: Gabler, Fernando. Hospital Clínico San Borja Arriarán; ChileFil: Campos, Mónica. Hospital Clínico San Borja Arriarán; ChileFil: Alvarado, Juan. Hospital Regional de Concepción - Dr. Guillermo Grant Benavente; ChileFil: Moisán, Fabricio. Hospital Regional de Concepción - Dr. Guillermo Grant Benavente; ChileFil: Spencer, Loreto. Hospital Regional de Concepción - Dr. Guillermo Grant Benavente; ChileFil: Nervi, Bruno. No especifíca;Fil: Carvajal Hausdorf, Daniel. Universidad del Desarrollo; ChileFil: Losada, Héctor. Universidad de La Frontera; ChileFil: Almau, Mauricio. Hospital de Rancagua; ChileFil: Fernández, Plinio. Hospital de Rancagua; ChileFil: Olloquequi, Jordi. Universidad de Barcelona; EspañaFil: Fuentes Guajardo, Macarena. Universidad de Tarapacá; ChileFil: Gonzalez-Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Bortolini, Maria Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Acuña Alonzo, Victor. No especifíca;Fil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerúFil: Ruiz-Linares, Andres. Colegio Universitario de Londres; Reino UnidoFil: Rothhammer, Francisco. Universidad de Tarapacá; ChileFil: Lorenzo Bermejo, Justo. Ruprecht Karls Universitat Heidelberg; Alemani

Mendelian Randomization Analysis of the Relationship Between Native American Ancestry and Gallbladder Cancer Risk

Background A strong association between the proportion of Native American ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest Native American people in Chile. We set out to investigate the causal association between Native American Mapuche ancestry and GBC risk, and the possible mediating effects of gallstone disease and body mass index (BMI) on this association. Methods Markers of Mapuche ancestry were selected based on the informativeness for assignment measure and then used as instrumental variables in two-sample mendelian randomization (MR) analyses and complementary sensitivity analyses. Result We found evidence of a causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% for every 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.6×10-5). Mapuche ancestry was also causally linked to gallstone disease (IVW risk increase of 3.6% per 1% increase in Mapuche proportion, 95% CI 3.1% to 4.0%, p = 1.0×10-59), suggesting a mediating effect of gallstones in the relationship between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative causal effect on BMI (IVW estimate -0.006 kg/m2 per 1% increase in Mapuche proportion, 95% CI -0.009 to -0.003, p = 4.4×10-5). Conclusions The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between Mapuche ancestry and GBC risk previously noted in observational studies appears to be causal, primary and secondary prevention strategies that take into account the individual proportion of Mapuche ancestry could be particularly efficient

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Combinations of single-top-quark production cross-section measurements and vertical bar f(LV)V(tb)vertical bar determinations at root s=7 and 8 TeV with the ATLAS and CMS experiments

This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb(-1) at = 7 TeV and 12.2 to 20.3 fb(-1) at = 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: t-channel, tW, and s-channel. The combined t-channel cross-sections are 67.5 +/- 5.7 pb and 87.7 +/- 5.8 pb at = 7 and 8 TeV respectively. The combined tW cross-sections are 16.3 +/- 4.1 pb and 23.1 +/- 3.6 pb at = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 +/- 1.4 pb at = 8 TeV. The square of the magnitude of the CKM matrix element V-tb multiplied by a form factor f(LV) is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation |V-td|, |V-ts| << |V-tb|. All the |f(LV)V(tb)|(2) determinations, extracted from individual ratios at = 7 and 8 TeV, are combined, resulting in |f(LV)V(tb)| = 1.02 +/- 0.04 (meas.) +/- 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions.Peer reviewe