Inventário da herpetofauna do Parque Nacional Talampaya, Patrimônio da Humanidade, na Argentina

Talampaya National Park (TNP) was designated a UNESCO World Heritage Site, together with Ischigualasto Provincial Park in 2000, but there is no list with updated information from reptiles and amphibians eighteen years after its creation. Therefore, we listed a complete inventory of the herpetofauna of TNP with the information obtained from bibliography, data from Argentina National Parks Administration (ranger reports and the species listed in their database) and fieldwork using pitfall traps, active search transects and pictures/material collected in the site. We confirm the occurrence of 35 species of herpetofauna in the TNP, including 29 reptiles and 6 amphibians. Some species found in TNP are of great value because their national conservation status is vulnerable (Chelonoidis chilensis, Liolaemus anomalus, Liolaemus riojanus) or even endangered (Boa constrictor occidentalis). Therefore, priority areas for conservation of these species should be proposed inside the park. Keywords: amphibians, conservation area, list of species, reptiles.O Parque Nacional Talampaya (TNP) foi declarado Patrimônio da Humanidade pela UNESCO, juntamente com o Parque Provincial Ischigualasto, em 2000, mas não há lista com informações atualizadas de répteis e anfíbios 18 anos após sua criação. Portanto, listamos um inventário completo da herpetofauna do TNP com as informações obtidas na bibliografia, dados da Administração de Parques Nacionais da Argentina (relatórios de guardas florestais e as espécies listadas em seu banco de dados) e trabalho de campo usando armadilhas de queda, transecções de pesquisa ativa e fotos/material coletado no site. Confirmamos a presença de 35 espécies da herpetofauna no TNP, incluindo 29 répteis e 6 anfíbios. Algumas espécies encontradas no TNP são de grande importância, pois seu estado de conservação nacional é vulnerável (Chelonoidis chilensis, Liolaemus anomalus, Liolaemus riojanus), ou mesmo em perigo (Boa constrictor occidentalis). Assim, áreas prioritárias para a conservação dessas espécies devem ser propostas para o parque.Palavras-chave: anfíbios, lista de espécies, répteis, unidade de conservação

Segundo encuentro de becarios y tesistas de la Facultad de Ciencias Naturales y Museo

El II Encuentro de Becarios/as y Tesistas de la FCNyM”, representa la continuación del “I EByT FCNyM” que fue realizado de forma virtual en el año 2020. Este encuentro es una iniciativa de becarios, becarias y tesistas doctorales con lugar de trabajo en la Facultad de Ciencias Naturales y Museo, y tiene el objetivo de generar un espacio permanente de diálogo y discusión. En esta nueva edición, realizada en forma híbrida (presencial y virtual) en el mes de octubre de 2022, se continuó con la visibilización de nuestro trabajo y con el intercambio de miradas y perspectivas. Asimismo, se extendió la invitación a participar a egresados/as recientes y a estudiantes de todas las carreras de posgrado de la FCNyM.El encuentro se dividió en tres módulos, cada uno con objetivos particulares. El primer módulo consistió en la exposición de temas de investigación y trabajos específicos que realicen los participantes, en este módulo se presentaron diez trabajos, que abarcaron temáticas de antropología, biología, paleontología y geología. El segundo módulo consistió en la exposición de dos conferencias magistrales, una relacionada a la salud mental de las personas tesistas o becadas, y otra relacionada al uso del software libre “R”. El último módulo consistió en un plenario donde se discutieron problemáticas que nos interpelan como doctorandos. Por lo anteriormente expresado, consideramos que este encuentro fue muy enriquecedor,fomentó la interacción entre pares y la interdisciplinariedad de quienes se encuentran transitando esta etapa fundamental de la formación profesional en investigación. El documento que se presenta es una compilación de los resúmenes de los trabajos y conferencias presentadas, junto con una breve síntesis gráfica de las exposiciones que tuvieron lugar durante la jornada. Agradecemos a todos su participación y compromiso.

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

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data