Variación geográfica de la composición y riqueza de plantas vasculares en los talares bonaerenses y su relación con el clima, sustrato, estructura del paisaje y uso

Tesis presentada para optar al Grado de Doctor en Ciencias NaturalesFil: Torres Robles, Silvia S.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin

Notes on the sexual condition of Myriophyllum aquaticum, Haloragaceae Notas sobre la condición sexual de Myriophyllum aquaticum, Haloragaceae

Resumen. Myriophyllum aquaticum (Vell.) Verdc. es nativa de Sudamérica con distribución pantropical. Esta especie ha sido citada como dioica, monoica y polígama. El objetivo de este trabajo es contribuir a la discusión sobre su condición sexual, basada en material de herbario, y apoyada por observaciones de campo. Se examinó material de herbario de Argentina. En la Reserva Natural de Punta Lara (Buenos Aires, Argentina), se muestrearon periódicamente veinte ramas para registrar el sexo de las flores presentes en cada verticilo durante el período de floración de 2002. Tanto en material de herbario, como en el campo, observamos especímenes con ramas con flores femeninas, especímenes con ramas con flores masculinas y especímenes con flores femeninas y masculinas en la misma rama. Algunos de estos materiales presentan frutos. Nuestras observaciones apoyan la idea que M. aquaticum no es una especie estrictamente dioica, al menos en Argentina. Palabras clave: Dioecia; Monoecia; Myriophyllum aquaticum; Punta Lara. Abstract. Myriophyllum aquaticum (Vell.) Verdc. is native of South America and has a pantropical distribution. This species has been cited as dioecious, monoecious and polygamous. The purpose of this paper was to contribute to the discussion of its sexual condition, based on herbarium material, and supported by field observations. Herbarium material from Argentina was examined. Also, twenty branches from the Punta Lara Nature Reserve (Buenos Aires, Argentina) were periodically sampled to record the sex of flowers present on each whorl during the flowering period of 2002. Both in herbarium material and in field, we observed specimens with branches bearing either female or male, and specimens with female and male flowers on the same branch. Some of these materials have also fruits. Our observations support the idea that M. aquaticum is not a strictly dioecious species, at least in Argentina

Material tipo de Carlos L. Spegazzini en el herbario del Museo de La Plata (LP), Argentina. II: Fabaceae

A catalogue of the Fabaceae type material of Carlos Luis Spegazzini (1858-1926) deposited in the herbarium of Museo de La Plata (LP), Argentina, is presented. Spegazzini and collaborators collected extensively in Argentina, mainly in Patagonia. As a result of these expeditions, Spegazzini´s collection of types includes ca. 700 specimens. The analysis of Fabaceae reveals 79 type specimens, 63 of which are deposited in LP. Thirty three taxa have resulted in nomina nuda, nomina illegitima, etc. The treatment includes a list of original names arranged alphabetically, the current names with authors, the exsiccata followed by the type category, the original citation or protologue, and all relevant observations. In addition, a list of specimens that were not found in LP, a list of the nomina illegitima, nomina invalida, nomina nova and nomina nuda, and a list of the Spegazzini´s genera are provided. The most representative illustrations attached to the type specimens, drawn by Spegazzini, are also included.Se presenta un catálogo del material tipo de Fabaceae de Carlos Luis Spegazzini (1858-1926) depositado en el Herbario del Museo de La Plata (LP), Argentina. Spegazzini y colaboradores colectaron extensivamente en Argentina, principalmente en Patagonia. Como resultado de estas expediciones, la colección de tipos de Spegazzini alcanza ca. 700 especímenes. El análisis de Fabaceae dio como resultado 79 especímenes, de los cuales 63 se hallan depositados en LP, y 33 resultaron nomina nuda, nomina illegitima, etc. El tratamiento incluye una lista de los nombres originales ordenados alfabéticamente, los nombres actuales con autores, la exsiccata seguida por la categoría del tipo, la cita original o protólogo, y observaciones consideradas relevantes. Además, se proporciona una lista de los especímenes que no se encontraron en LP, una lista de la nomina illegitima, nomina invalida, nomina nova y nomina nuda, y una lista de los géneros de Spegazzini. También son incluidas las ilustraciones más representativas adjuntas a los materiales tipo realizadas por Spegazzini.Facultad de Ciencias Naturales y Muse

Producción anual de Carne/HA en pastoreo rotacional en los zacates ferrer, estrella de áfrica y señal, con y sin fertilizantes, en Hueytamalco, Pue.

En el Centro Experimental Pecuario de Hueytamalco, Pue., se investigó en los zacates introducidos Ferrer, Cynodon dactylon; Señal, Brachiaria brizantha, y Estrella de África, Cynodon plectostachyus, su potencial de producción anual y estacional de carne. Se utilizó un diseño completamente al azar con diferente número de animales por tratamiento: 0 y 150 kg N/ha con una carga de dos y cuatro animales/ha, respectivamente. La respuesta a la fertilización fue altamente significativa, obteniendo en promedio 618 kg carne/ha en los zacates fertilizados y 325 kg carne/ha en los zacates no fertilizados. La fertilización permitió un incremento de 92% en producción de carne/ha. Los zacates Ferrer, Estrella y Señal con cuatro animales/ha y 150 kg N/ha alcanzaron en un año de pastoreo una producción de 636, 583 y 637 kg carne/ha con una ganancia diaria promedio de 437, 400 y 438 g. respectivamente, diferencias que no fueron estadísticamente significativas (

Relationship between Serum Concentration of Uric Acid and Insulin Secretion among Adults with Type 2 Diabetes Mellitus

To determine the relationship between serum concentrations of uric acid and insulin secretion with hyperglycaemic clamp technique among adults with type 2 diabetes mellitus (DM2) without hyperuricemia, we carried out a cross-sectional study on 45 patients of both gender. We observed correlation between uric acid with male gender r = 0.710 (P = 0.001). Also correlation between uric acid and total insulin secretion was positive r = 0.295 (P = 0.049). As well as a positive correlation adjusted for body mass index was demonstrated for the first, second, and total phases of insulin secretion, respectively, r = 0.438 (P = 0.022), r = 0.433 (P = 0.022), and r = 0.439 (P = 0.024). Serum concentration of uric acid showed a positive relationship with the total phase of insulin secretion; even in states prior to hyperuricemia, uric acid can play an important role in the function of the beta cell in patients with DM2

Loss of caveolin-1 is associated with a decrease in beta cell death in mice on a high fat diet

Indexación: Scopus.Elevated free fatty acids (FFAs) impair beta cell function and reduce beta cell mass as a consequence of the lipotoxicity that occurs in type 2 diabetes (T2D). We previously reported that the membrane protein caveolin-1 (CAV1) sensitizes to palmitate-induced apoptosis in the beta pancreatic cell line MIN6. Thus, our hypothesis was that CAV1 knock-out (CAV1 KO) mice subjected to a high fat diet (HFD) should suffer less damage to beta cells than wild type (WT) mice. Here, we evaluated the in vivo response of beta cells in the pancreatic islets of 8-week-old C57Bl/6J CAV1 KO mice subjected to a control diet (CD, 14% kcal fat) or a HFD (60% kcal fat) for 12 weeks. We observed that CAV1 KO mice were resistant to weight gain when on HFD, although they had high serum cholesterol and FFA levels, impaired glucose tolerance and were insulin resistant. Some of these alterations were also observed in mice on CD. Interestingly, KO mice fed with HFD showed an adaptive response of the pancreatic beta cells and exhibited a significant decrease in beta cell apoptosis in their islets compared to WT mice. These in vivo results suggest that although the CAV1 KO mice are metabolically unhealthy, they adapt better to a HFD than WT mice. To shed light on the possible signaling pathway(s) involved, MIN6 murine beta cells expressing (MIN6 CAV) or not expressing (MIN6 Mock) CAV1 were incubated with the saturated fatty acid palmitate in the presence of mitogen-activated protein kinase inhibitors. Western blot analysis revealed that CAV1 enhanced palmitate-induced JNK, p38 and ERK phosphorylation in MIN6 CAV1 cells. Moreover, all the MAPK inhibitors partially restored MIN6 viability, but the effect was most notable with the ERK inhibitor. In conclusion, our results suggest that CAV1 KO mice adapted better to a HFD despite their altered metabolic state and that this may at least in part be due to reduced beta cell damage. Moreover, they indicate that the ability of CAV1 to increase sensitivity to FFAs may be mediated by MAPK and particularly ERK activation. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.https://www.mdpi.com/1422-0067/21/15/522

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

New host, geographical records, and factors affecting the prevalence of helminths infection from synanthropic rodents in Yucatán, Mexico

The aim of this paper was to study the occurrence of helminths in Mus musculus and Rattus rattus from urban, suburban and rural settlements in Yucatán, Mexico; and to analyse the host factors (e.g. sex) related to helminths' distribution. Helminths in a total of 279 rodents were surveyed by visual examination of the liver for metacestodes and faecal examination for helminth eggs using the formalin-ethyl acetate sedimentation technique. The cestodes Hydatigera taeniaeformis (metacestodes detected in the liver) and Hymenolepis diminuta, and the nematodes Aspiculuris sp., Nippostrongylus brasiliensis, Syphacia muris, Syphacia obvelata, and Trichuris muris were identified. In M. musculus, the prevalence of infection with T. muris and H. taeniaeformis was higher in the rural village compared to those in the suburban neighbourhood. For R. rattus, a higher prevalence of infection with H. diminuta was found in the urban site compared to that in the suburban site. This study reports the occurrence of H. diminuta among rodents living in close proximity to humans, representing a potential public health risk. In addition, this survey increases our understanding of dynamic transmission among intestinal helminths recorded in Yucatán, Mexico.Centro de Estudios Parasitológicos y de Vectore

A survey of zoonotic pathogens carried by house mouse and black rat populations in Yucatan, Mexico

The house mouse (Mus musculus) and the black rat (Rattus rattus) are reservoir hosts for zoonotic pathogens, several of which cause neglected tropical diseases (NTDs). Studies of the prevalence of these NTD-causing zoonotic pathogens, in house mice and black rats from tropical residential areas are scarce. Three hundred and two house mice and 161 black rats were trapped in 2013 from two urban neighbourhoods and a rural village in Yucatan, Mexico, and subsequently tested for Trypanosoma cruzi, Hymenolepis diminuta and Leptospira interrogans. Using the polymerase chain reaction we detected T. cruzi DNA in the hearts of 4.9% (8/165) and 6.2% (7/113) of house mice and black rats, respectively. We applied the sedimentation technique to detect eggs of H. diminuta in 0.5% (1/182) and 14.2% (15/106) of house mice and black rats, respectively. Through the immunofluorescent imprint method, L. interrogans was identified in 0.9% (1/106) of rat kidney impressions. Our results suggest that the black rat could be an important reservoir for T. cruzi and H. diminuta in the studied sites. Further studies examining seasonal and geographical patterns could increase our knowledge on the epidemiology of these pathogens in Mexico and the risk to public health posed by rodents.Centro de Estudios Parasitológicos y de Vectore

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente