Pastoreo rotativo en producciones bovinas extensivas como herramienta para la conservación de la biodiversidad en el Monte Central - Mendoza

Chillo, Verónica. Universidad Nacional de Río Negro ( Sede Andina). Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Bariloche, Río Negro, Argentina.Ojeda, Ricardo A. CONICET. Instituto Argentino de Investigaciones de Zonas Áridas (IADIZA). Grupo de Investigaciones de la Biodiversidad. Mendoza, Argentina.38-49En la región de Cuyo, la ganadería es la principal actividad productiva de secano y mostró un marcado aumento en los últimos 30 años. La pérdida de la biodiversidad asociada a la degradación por sobre-pastoreo merece especial atención por sus consecuencias sobre el funcionamiento del ecosistema. En el desierto del monte central, el pastoreo continuo es la práctica dominante para la producción bovina extensiva. Como alternativa, en el campo experimental El Divisadero (Mendoza) se implementó una estrategia de pastoreo rotativo que implica acomodar los tiempos de descanso de los potreros en base a la disponibilidad de forraje en las pasturas. Se presenta una revisión donde se sintetizan e integran resultados ya publicados que analizaron la respuesta de la biodiversidad y la dinámica del ecosistema a la intensidad de pastoreo (estimado como la distancia a la aguada) en condiciones de pastoreo rotativo y continuo en el desierto del monte central, y su interacción con factores ambientales. La presente revisión permite concluir que: a) la diversidad de plantas, hormigas y pequeños mamíferos varía dentro de cada estrategia de manejo según la intensidad de pastoreo; y b) bajo pastoreo rotativo, los efectos negativos del aumento en la intensidad de pastoreo sobre la diversidad son menores que bajo pastoreo continuo. Lo mismo ocurre con la funcionalidad del ecosistema, con un menor impacto sobre la tasa de descomposición y menor ocurrencia de umbrales de degradación bajo pastoreo rotativo. Se propone que los tiempos de descanso, acoplados con períodos de mayor precipitación, pueden ser herramientas para el manejo sustentable y la restauración de este ecosistema

Enhanced at puberty 1 (EAP1) is a new transcriptional regulator of the female neuroendocrine reproductive axis

The initiation of mammalian puberty and the maintenance of female reproductive cycles are events controlled by hypothalamic neurons that secrete the decapeptide gonadotropin-releasing hormone (GnRH). GnRH secretion is, in turn, controlled by changes in neuronal and glial inputs to GnRH-producing neurons. The hierarchical control of the process is unknown, but it requires coordinated regulation of these cell-cell interactions. Here we report the functional characterization of a gene (termed enhanced at puberty 1 [EAP1]) that appears to act as an upstream transcriptional regulator of neuronal networks controlling female reproductive function. EAP1 expression increased selectively at puberty in both the nonhuman primate and rodent hypothalamus. EAP1 encoded a nuclear protein expressed in neurons involved in the inhibitory and facilitatory control of reproduction. EAP1 transactivated genes required for reproductive function, such as GNRH1, and repressed inhibitory genes, such as preproenkephalin. It contained a RING finger domain of the C3HC4 subclass required for this dual transcriptional activity. Inhibition of EAP1 expression, targeted to the rodent hypothalamus via lentivirus-mediated delivery of EAP1 siRNAs, delayed puberty, disrupted estrous cyclicity, and resulted in ovarian abnormalities. These results suggest that EAP1 is a transcriptional regulator that, acting within the neuroendocrine brain, contributes to controlling female reproductive function.This work was supported by grants from the NIH, the National Institute of Child Health and Human Development/NIH (to S.R. Ojeda), the European Society for Paediatric Endocrinology (to H. Jung), the German Research Foundation (to S. Heger), and the European Commission (PIONEER to S. Heger)

Development and evaluation of equations to predict body weight of Pelibuey ewes using heart girth

The aim of this study was to develop and evaluate equations to predict body weight (BW) using heart girth (HG) in Pelibuey ewes. For model develop a data set composed by 366, 3-year-old, non-pregnant and non-lactating ewes; with a mean BW of 45.7±9.16 kg and HG of 87.55± 7.93 cm was used. A linear equation was fitted: BW= -47.97 (±2.01*) + 1.07 (±0.02**)×HG (R2 = 0.86, RMSE = 3.46, , y n = 366). A second data set composed by 67 animals, with similar characteristics (BW of 38.25± 8.62 kg and HG of 80.37± 7.03 cm) was used to evaluate the developed equations. For the evaluation, the relationship between observed and predicted values of BW by linear regression, the mean squared error of prediction (MSEP) and root MSEP (RMSEP), and concordance correlation coefficient analysis were used. The proposed equation was highly precise (r2 =0.913) and accurate (Cb=0.996) with a reproducibility index of 0.95. The MEF have indicates a higher efficiency of prediction with higher proportion of the total variance of the observed values been explained by the predicted data (0.91). The partition of the MSEP have indicated a very small mean bias (0.082). The systematic bias have shown that only 1.93% of the error of prediction was associated with the slope and most of the error was explained by the random component indicating small biases with the predictions. The proposed equation accurately and precisely estimated the BW of Pelibuey ewe using HG and therefore is recommended to be used

Revision and analysis of the chromosome variability in the speciose genus Akodon (Rodentia, Sigmodontinae), including new data from Argentina

Abstract Rodentia has a high species number and chromosomal variability. The South American genus Akodon is one of the most speciose muroids, with more than 40 species included in several species groups. Here, we characterize cytogenetically specimens of Akodon from central-western Argentina. Subsequently, we reviewed and analyzed the cytogenetic data for this genus, build a phylogeny and mapped chromosome changes to interpret its evolution. Specimens of A. dolores from central-western Argentina have 2n=42-44/FNa=44 (46, 48) due to a Robertsonian rearrangement. Our data expand the distribution range known for this polymorphism and confirm its geographic structure. Other specimens had 2n=40/FNa=40, representing populations of A. oenos, A. polopi, and A. spegazzinii. All karyotypes have a low amount of heterochromatin, concentrated in centromeres and sex chromosomes, as in other rodents. The complement with 2n=40/FNa=40 is the most frequent in Akodon and is shared by most species in some groups. Chromosome numbers are very diverse. The FNa shows less variability; FNa=42 was recovered as ancestral, excluding A. mimus, which was connected at the base of the Akodon tree and has FNa=44. This indicates a complex chromosome evolution in Akodon, and suggests that reductions and increases in the 2n and FNa evolved independently in some lineages

Plan de negocios para la creaci?n de una plataforma virtual colaborativa de estacionamientos

Se ha establecido la realizaci?n de encuestas para profundizar en el an?lisis del mercado que se desea conocer. Este m?todo de investigaci?n nos permite conocer de primera mano las opiniones y preferencias de los potenciales usuarios para una herramienta novedosa en el mercado. Gracias a la Internet los costos de realizar una encuesta pr?cticamente han desaparecido y que al ser desarrollado en la intimidad de su smartphone de manera privada el nivel de veracidad es alto. El estudio de mercado muestra un alto inter?s por parte de los conductores de hacer sus reservaciones de estacionamientos a trav?s de un aplicativo m?vil, como es la soluci?n que estamos planteando en este plan de negocio, hecho similar ocurre con aquellos propietarios que tienen un estacionamiento. El modelo de negocio sustentado es una soluci?n tecnol?gica y econ?micamente viable, que emerge como resultado de la b?squeda de una gesti?n eficiente a la problem?tica del tr?fico y la falta de espacios de aparcamiento en las grandes urbes y, que mediante este modelo de negocio se pretende resolver

Ipsilateral vagotomy to unilaterally ovariectomized pre-pubertal rats modifies compensatory ovarian responses

The present study evaluates the participation of the vagus nerve in pre-pubertal rats with unilateral ovariectomy on puberty onset, and on progesterone, testosterone and estradiol serum levels, and the compensatory responses of the ovary. Unilateral vagotomy did not modify the onset of puberty in unilaterally ovariectomized rats. Ovulation rates of animals with the left vagus nerve sectioned and the left ovary in-situ was lower than in rats with only unilateral ovariectomy. Sectioning the left vagus to 32-day old rats with the left ovary in-situ resulted in lower compensatory ovarian hypertrophy than in rats with right unilateral ovariectomy. Twenty-eight or 32-day old animals with sectioning of the right vagus nerve and the right ovary in situ showed higher compensatory ovulation. Twenty-eight -day old rats with the right ovary in situ had higher progesterone and testosterone levels than animals of the same age with the left ovary in-situ. Compared to animals with the right ovary in situ, animals treated at 32-days of age, sectioning the ipsi-lateral vagus nerve resulted in higher progesterone levels. Higher progesterone levels were observed in 28- and 32 days old rats with the left ovary in situ and left vagus nerve sectioned. Thirty-two day old animals with the right ovary in situ and right vagus nerve sectioned had higher progesterone levels than rats of the same age with the left ovary in situ and left vagus nerve sectioned. Left vagotomy to 28-day old rats with the left ovary in situ resulted in higher testosterone levels, a reverse response to that observed in animals with sectioning of the right vagus and the right ovary in situ. Thirty-two day old rats with the left ovary in situ and left vagus nerve sectioned showed lower testosterone levels than animals without vagotomy and with the left ovary in situ

USH2A is a Meissner’s corpuscle protein necessary for normal vibration sensing in mice and humans

Fingertip mechanoreceptors comprise sensory neuron endings together with specialized skin cells that form the end-organ. Exquisitely sensitive, vibration-sensing neurons are associated with Meissner’s corpuscles in the skin. In the present study, we found that USH2A, a transmembrane protein with a very large extracellular domain, was found in terminal Schwann cells within Meissner’s corpuscles. Pathogenic USH2A mutations cause Usher’s syndrome, associated with hearing loss and visual impairment. We show that patients with biallelic pathogenic USH2A mutations also have clear and specific impairments in vibrotactile touch perception, as do mutant mice lacking USH2A. Forepaw rapidly adapting mechanoreceptors innervating Meissner’s corpuscles, recorded from Ush2a−/− mice, showed large reductions in vibration sensitivity. However, the USH2A protein was not found in sensory neurons. Thus, loss of USH2A in corpuscular end-organs reduced mechanoreceptor sensitivity as well as vibration perception. Thus, a tether-like protein is required to facilitate detection of small-amplitude vibrations essential for the perception of fine-grained tactile surfaces.The present study was funded by grants from the Deutsche Forschungsgemeinshaft (grant nos. SFB665-B6 to G.R.L., SFB1315 to J.F.A.P. and SFB1158-A01 to S.G.L.) and grants from the European Research Council (grant nos. 789128 to G.R.L. and ERC-2015-CoG-682422 to J.F.A.P.). Additional funding was from the Institute of Health Carlos III (Spanish Ministry of Science and Innovation, grant no. FIS PI16/00539 to J.M.).Peer reviewe

The global impact of the COVID-19 pandemic on the management and course of chronic urticaria

Introduction: The COVID-19 pandemic dramatically disrupts health care around the globe. The impact of the pandemic on chronic urticaria (CU) and its management are largely unknown. Aim: To understand how CU patients are affected by the COVID-19 pandemic; how specialists alter CU patient management; and the course of CU in patients with COVID-19. Materials and Methods: Our cross-sectional, international, questionnaire-based, multicenter UCARE COVID-CU study assessed the impact of the pandemic on patient consultations, remote treatment, changes in medications, and clinical consequences. Results: The COVID-19 pandemic severely impairs CU patient care, with less than 50% of the weekly numbers of patients treated as compared to before the pandemic. Reduced patient referrals and clinic hours were the major reasons. Almost half of responding UCARE physicians were involved in COVID-19 patient care, which negatively impacted on the care of urticaria patients. The rate of face-to-face consultations decreased by 62%, from 90% to less than half, whereas the rate of remote consultations increased by more than 600%, from one in 10 to more than two thirds. Cyclosporine and systemic corticosteroids, but not antihistamines or omalizumab, are used less during the pandemic. CU does not affect the course of COVID-19, but COVID-19 results in CU exacerbation in one of three patients, with higher rates in patients with severe COVID-19. Conclusions: The COVID-19 pandemic brings major changes and challenges for CU patients and their physicians. The long-term consequences of these changes, especially the increased use of remote consultations, require careful evaluation