Sites for Gamma-ray Astronomy in Argentina

We have searched for possible sites in Argentina for the installation of large air Cherenkov telescope arrays and water Cherenkov systems. At present seven candidates are identified at altitudes from 2500 to 4500 m. The highest sites are located at the Northwest of the country, in La Puna. Sites at 2500 and 3100 m are located in the West at El Leoncito Observatory, with excellent infrastructure. A description of these candidate sites is presented with emphasis on infrastructure and climatology.Comment: Submitted to Proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008

A New Kind of Quinonic-Antibiotic Useful Against Multidrug-Resistant S. aureus and E. faecium Infections

Indexación: Scopus.A rapid emergence of resistant bacteria is occurring worldwide, endangering the efficacy of antibiotics and reducing the therapeutic arsenal available for treatment of infectious diseases. In the present study, we developed a new class of compounds with antibacterial activity obtained by a simple, two step synthesis and screened the products for in vitro antibacterial activity against ATCC® strains using the broth microdilution method. The compounds exhibited minimum inhibitory concentrations (MIC) of 1⁻32 μg/mL against Gram-positive ATCC® strains. The structure⁻activity relationship indicated that the thiophenol ring is essential for antibacterial activity and the substituents on the thiophenol ring module, for antibacterial activity. The most promising compounds detected by screening were tested against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VREF) clinical isolates. We found remarkable activity against VREF for compounds 7 and 16, were the MIC50/90 were 2/4 µg/mL and 4/4 µg/mL, respectively, while for vancomycin the MIC50/90 was 256/512 µg/mL. Neither compound affected cell viability in any of the mammalian cell lines at any of the concentrations tested. These in vitro data show that compounds 7 and 16 have an interesting potential to be developed as new antibacterial drugs against infections caused by VREF.https://www.mdpi.com/1420-3049/23/7/177

Estudio de Seeing en la Zona del Cerro Champaquí (I)

Resumen: Se reportan los resultados del estudio más reciente de seeing que hemos realizado en la zona del Cerro Champaquí (2800 m) en el cordón de las Sierras Grandes en la Provincia de Córdoba. Se describe además, el dispositivo DIMM de alta frecuencia construido para este trabajo. Este instrumento se empleó en otros muestreos de seeing realizados en las provincias de San Juan y San Luis como parte de un proyecto de búsqueda de sitios con muy baja turbulencia atmosférica y adecuados para observaciones con óptica activa y adaptable en el rango infrarrojo cercano, iniciado en 2006. Dos de estos sitios han sido monitoreados un total de 46 noches distribuidas en seis meses del periodo 2011-2012. Los resultados indican que se darían condiciones de seeing estable, inferior al segundo de arco por prolongados períodos de tiempo, en al menos un sitio del cordón montañoso del SO de Córdoba y NE de San Luis.Abstract: Abstract. We report the results of the most recent seeing feasibility study performed in the region of Cerro Champaquí (2800 m) at the mountain range of Sierras Grandes at the Province of Córdoba. We also describe the high frequency DIMM device built for this and other seeing samplings obtained at the provinces of San Juan, San Luis and Córdoba. This work is part of a long term project started in 2006, in search of sites of very low turbulence and suited for near infrared telescopes with active and adaptive optics. Two of the sites have been monitored during a total of 46 nights distributed in six months of the period 2011-2012. The preliminary results suggest the existence of ‘sub-arcsecond’ seeing conditions during extended periods of time in at least one location in the mountain range in the SW of Córdoba and NE of San Luis provinces.www.astronomiaargentina.orgpublishedVersionFil: Díaz, Rubén Joaquín. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Díaz, Rubén Joaquín. Conicet, Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Argentina.Meteorología y Ciencias Atmosférica

Polycystic ovary syndrome

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the presence of hyperandrogenism, ovulatory dysfunction and PCOM. Treatment should be tailored to the complaints and needs of the patient and involves targeting metabolic abnormalities through lifestyle changes, medication and potentially surgery for the prevention and management of excess weight, androgen suppression and/or blockade, endometrial protection, reproductive therapy and the detection and treatment of psychological features. This Primer summarizes the current state of knowledge regarding the epidemiology, mechanisms and pathophysiology, diagnosis, screening and prevention, management and future investigational directions of the disorder.Robert J Norman, Ruijin Wu and Marcin T Stankiewic

Ovarian estradiol modulates the stimulatory effect of ovulation-inducing factor (OIF) on pituitary LH secretion in llamas

This study was designed to: 1) characterize the effect of ovulation-inducing factor (OIF) on pituitary LH secretion in ovariectomized (OVX) llamas; and 2) determine the effect of OIF on LH secretion in OVX llamas pretreated with estradiol-17 beta (E-17 beta) or estradiol benzoate (EB). In Experiment 1, intact and OVX llamas (n = 5 or 6 per group) were assigned to a two by two factorial design: 1) Intact llamas treated with 1 mL of phosphate buffered saline (PBS); 2) Intact llamas treated with 1 mg of purified OIF; 3) OVX llamas treated with 1 mL of PBS; or 4) OVX llamas treated with 1 mg of purified OIF. In Experiment 2, intact and OVX llamas (n = 5 or 6 per group) were randomly assigned to the following groups: 1) Intact llamas treated with I mg of purified OIF; 2) OVX llamas treated with 1.0 mL of PBS; 3) OVX llamas treated with 1.0 mg of purified OIF; 4) OVX llamas primed with E-17 beta, followed by 1.0 mg of purified OIF. Experiment 3 was similar as described for Experiment 2, except that priming was done with EB. In Experiment 1, animal category by treatment and animal category by treatment by time interactions tended (P = 0.08) to affect LH concentration. The effect of OIF on LH released was partly restored (P < 0.05), to the values observed for the intact OIF-treated females, when OVX llamas were primed with E-17 beta or BE (Experiments 2 and 3). We concluded that peripheral estradiol concentrations in llamas partially modulates the effect of OIF on pituitary LH secretion; however, other ovarian factor(s) could also participate in this modulatory action. (C) 2012 Elsevier Inc. All rights reserved

Prenatal testosterone exposure disrupts Insulin secretion and promotes insulin resistance

Hyperandrogenemia and metabolic disturbances during postnatal life are strongly linked both to polycystic ovary syndrome and other conditions that arise from prenatal exposure to androgen excess. In an animal model of this condition, we reported that insulin sensitivity (IS) was lower in young female sheep born to testosterone-treated mothers versus sheep born to non-exposed mothers (control). This lower insulin sensitivity remains throughout reproductive life. However, it is unknown whether abnormal postnatal levels of testosterone (T) further decrease IS derived from prenatal exposure to testosterone. Therefore, we assessed the effects of an acute testosterone administration (40 mg) on IS and insulin secretion during an intravenous glucose tolerance test performed at 40 weeks of age (adulthood) in previously ovariectomized sheep at 26 weeks of age (prepuberty), that were either prenatally exposed to testosterone (T-females, n = 6) or not (C-females, n = 6). The incremental area under the curve of insulin was greater in C-females both with or without the acute testosterone treatment (P < 0.05). The ISI-Composite was lower after an acute testosterone treatment, only in T-females. We conclude that prenatal exposure to testosterone disrupts pancreatic insulin secretion in response to glucose and that in this setting further hyperandrogenemia may predispose to lower insulin sensitivity.Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) CONICYT FONDECYT 114043

Ovarian morphometry and mRNA expression of antimullerian hormone (AMH), follicle stimulating hormone receptor (FSHR) and nuclear factor kappa B (NFκB) in growing follicles of female lambs prenatally exposed to testosterone Morfometría ovárica y expresión

Antenatal exposure to testosterone (T) has a series of consequences on postnatal reproductive parameters in females of several animal species. In sheep born under this condition the ovaries are characterized by an increased number of growing follicles. If such disruptions are manifested early in life or involve changes in follicular recruitment and ovary paracrine environment, it remains unclear. This study addressed the impact of prenatal T on ovarian morphometry and the mRNA expression of ovarian anti-mullerian hormone (AMH), FSH receptor (FSHR) and nuclear factor kappa B (NFκB, a transcription factor for AMH), factors that are involved in the growth and selection of the dominant follicle. At 4 weeks of age, female lambs born to dams treated with 30 mg of T propionate twice weekly from day 30 to day 90, followed by 40 mg of T propionate from day 90 to day 120 of pregnancy (T females), showed similar number of primordial, primary, secondary and antral follicles than control females (

Altered testicular development as a consequence of increase number of sertoli cell in male lambs exposed prenatally to excess testosterone

The reprograming effects of prenatal testosterone (T) treatment on postnatal reproductive parameters have been studied extensively in females of several species but similar studies in males are limited. We recently found that prenatal T treatment increases Sertoli cell number and reduced spermatogenesis in adult rams. If such disruptions are manifested early in life and involve changes in testicular paracrine environment remain to be explored. This study addresses the impact of prenatal T excess on testicular parameters in infant males, including Sertoli cell number and expression of critical genes [FSH receptor (FSHR), androgen receptor (AR), transforming growth factor beta 1 (TGFB1), 3 (TGFB3), transforming growth factor beta type 1 receptor, (TGFBR1), and anti-Mullerian hormone (AMH)] modulating testicular function. At 4 week of age, male lambs born to dams treated with 30 mg of T propionate twice weekly from day 30 to 90, followed by 40 mg of T propionate from day 90 to 120 of pregnancy (T-males), had a higher number of Sertoli cells/ testis compared to C-males. Expression level of AMH, TGFB1, and AR also tended to be lower in T-males. These findings provide evidence that impact of fetal exposure to T excess is evident early in postnatal life, mainly characterized by an increase in Sertoli cell number. This could explain the testicular dysfunction observed in adult rams.Fil: Rojas García, Pedro P.. Universidad de Concepción; ChileFil: Recabarren, Mónica P.. Universidad de Concepción; ChileFil: Sir Petermann, Teresa. Universidad de Santiago de Chile; ChileFil: Rey, Rodolfo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones Endocrinológicas; ArgentinaFil: Palma, Sergio. Universidad de Concepción; ChileFil: Carrasco, Albert. Universidad de Concepción; ChileFil: Pérez Marín, Carlos C.. Universidad de Córdoba; ArgentinaFil: Padmanabhan, Vasantha. University Of Michigan; Estados UnidosFil: Recabarren, Sergio E.. Universidad de Concepción; Chil

Prenatal testosterone excess alters Sertoli and germ cell number and testicular FSH receptor expression in rams

Exposure to excess testosterone (T) during fetal life has a profound impact on the metabolic and reproductive functions in the female's postnatal life. However, less is known about the effects of excess testosterone in males. The aim of the present study was to evaluate the impact (consequences) of an excess of T during fetal development on mature male testis. The testicular evaluation was by histological analysis and by determination of mRNA expression of the FSH receptor (FSH-R), transforming growth factor-β type I receptor (TβR-I), and two members of the TGF-β superfamily, transforming growth factor-β3 (TGFβ3) and anti-Müllerian hormone (AMH) in males born to mothers receiving an excess of T during pregnancy. At 42 wk of age, postpubertal males born to mothers treated with 30 mg of T propionate twice weekly from day 30 to 90, followed by 40 mg of T propionate from day 90 to 120 of pregnancy (T males), showed higher concentrations of FSH in response to a GnRH analog, a higher number of Sertoli cells/seminiferous tubule cross-section, and a lower number of germ cells/tubules (P < 0.05) than control males (C males) born to mothers treated with the vehicle. The mRNA expression of FSH-R and of TβR-I was higher in T males compared with C males (P < 0.05). Moreover, in T males, AMH expression level correlated negatively with the expression level of TGFβ3. In C males, this latter correlation was not observed. These results suggest that prenatal exposure to an excess of T can negatively modify some histological and molecular characteristics of the mature testis.Fil: Rojas García, Pedro P.. Universidad de Concepción; ChileFil: Recabarren, Mónica. Universidad de Concepción; ChileFil: Sarabia, Luis. Universidad de Chile; ChileFil: Schön, Jennifer. Freie Universität; AlemaniaFil: Gabler, Christoph. Freie Universität; AlemaniaFil: Einspanier, Ralf. Freie Universität; AlemaniaFil: Maliqueo, Manuel. Universidad de Chile; ChileFil: Sir Petermann, Teresa. Universidad de Chile; ChileFil: Rey, Rodolfo Alberto. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Biología Celular e Histología; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Recabarren, Sergio E.. Universidad de Concepción; Chil