How feedback inhibition shapes spike-timing-dependent plasticity and its implications for recent Schizophrenia models

It has been shown that plasticity is not a fixed property but, in fact, changes depending on the location of the synapse on the neuron and/or changes of biophysical parameters. Here we investigate how plasticity is shaped by feedback inhibition in a cortical microcircuit. We use a differential Hebbian learning rule to model spike-timing dependent plasticity and show analytically that the feedback inhibition shortens the time window for LTD during spike-timing dependent plasticity but not for LTP. We then use a realistic GENESIS model to test two hypothesis about interneuron hypofunction and conclude that a reduction in GAD67 is the most likely candidate as the cause for hypofrontality as observed in Schizophrenia

Reliability assessment of ultrasound muscle echogenicity in patients with rheumatic diseases: Results of a multicenter international web-based study

ObjectivesTo investigate the inter/intra-reliability of ultrasound (US) muscle echogenicity in patients with rheumatic diseases.MethodsForty-two rheumatologists and 2 radiologists from 13 countries were asked to assess US muscle echogenicity of quadriceps muscle in 80 static images and 20 clips from 64 patients with different rheumatic diseases and 8 healthy subjects. Two visual scales were evaluated, a visual semi-quantitative scale (0–3) and a continuous quantitative measurement (“VAS echogenicity,” 0–100). The same assessment was repeated to calculate intra-observer reliability. US muscle echogenicity was also calculated by an independent research assistant using a software for the analysis of scientific images (ImageJ). Inter and intra reliabilities were assessed by means of prevalence-adjusted bias-adjusted Kappa (PABAK), intraclass correlation coefficient (ICC) and correlations through Kendall’s Tau and Pearson’s Rho coefficients.ResultsThe semi-quantitative scale showed a moderate inter-reliability [PABAK = 0.58 (0.57–0.59)] and a substantial intra-reliability [PABAK = 0.71 (0.68–0.73)]. The lowest inter and intra-reliability results were obtained for the intermediate grades (i.e., grade 1 and 2) of the semi-quantitative scale. “VAS echogenicity” showed a high reliability both in the inter-observer [ICC = 0.80 (0.75–0.85)] and intra-observer [ICC = 0.88 (0.88–0.89)] evaluations. A substantial association was found between the participants assessment of the semi-quantitative scale and “VAS echogenicity” [ICC = 0.52 (0.50–0.54)]. The correlation between these two visual scales and ImageJ analysis was high (tau = 0.76 and rho = 0.89, respectively).ConclusionThe results of this large, multicenter study highlighted the overall good inter and intra-reliability of the US assessment of muscle echogenicity in patients with different rheumatic diseases

Avances en la elaboración de un sistema termosolar inteligente de descarga pulsada

Se presenta la elaboración y evaluación de un prototipo termosolar de descarga pulsada programable. El mismo se basa en un sistema electrónico inteligente, adquisidor y de control, que decide las estrategias de descarga del agua caliente que se genera en un absorbedor construido con una larga manguera negra de polietileno. Las descargas se realizan hacia un tanque aislado al momento en que la temperatura del agua en el absorbedor llega a cierto valor determinado. Este controlador es diseñado de tal manera de poder programar las estrategias que maximicen la eficiencia y/o la producción total de agua caliente en distintas condiciones ambientales. Según la simulación térmica-solar presentada en otro trabajo, se espera que este sistema pueda producir grandes cantidades de agua caliente a un muy bajo costo, y satisfacer demandas tanto residenciales como industriales.Fil: Olivares, M.. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Juanico, Luis Eduardo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Lalla, Nicolás. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tilca, Fernando Florentin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; Argentin

Effects of fishery practices on fecundity of two lithodid crab species of commercial interest in Southern South America

The fishery of Lithodes santolla is the second most productive lithodid crab fishery in the world and in southernmost South America is considered a mixed fishery due to its co-occurrence with Paralomis granulosa. Fishing takes place in Argentina and Chile, where regulations restrict to land only males larger than a legal size, but with variable fishing seasons. All females and small males must be returned to water. Both species have long periods of embryogenesis. Individual fishers operate on a small geographic scale, following lithodid crabs which are typically confined to channels, fjords or straits. Therefore females can be fished and discarded on multiple occasions throughout egg-bearing period. We studied the effect of the fishing practices on the fecundity of L. santolla and P. granulosa. First, we experimentally evaluated the effect of seven repeated return-to-water simulations in different conditions: aerial exposition or aerial exposition followed by a free fall (FF) or ramp. Secondly and only in L. santolla, we tested the effect on the egg-loss of different stocking densities followed by a FF return-to-water. Finally, we estimated the fecundity at the beginning and at the end of the egg-bearing period in females of L. santolla. The FF produced a high egg-loss and did not increase with the trial repetitions in L. santolla. Female P. granulosa showed a similar egg-loss pattern for all treatments, and overall lost fewer eggs than female L. santolla. In P. granulosa except for the FF, the trial repetition produced an increase in the egg-loss. In L. santolla there was no effect on the egg-loss due to stocking densities. Based on the field studies, fecundity of L. santolla decreased during the egg-bearing period. This study demonstrated the effects of repetitive fishing events on the fecundity in two lithodid species of commercial interest.Fil: Di Salvatore, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Gowland Sainz, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Florentin, Olga Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Screening for minor changes in the distal part of the human dystrophin gene in Greek DMD/BMD patients

The distal part of the human dystrophin gene is characterised by particular features and seems to play an important functional role. Additionally in recent years several data have implicated minor mutations in this gene region in some patients,vith mental retardation (MR), In order to screen for pathogenic mutations at the distal part of the human dystrophin gene we have used single-strand conformation analysis of products amplified by polymerase chain reaction (PCR-SSCA) in 35 unrelated male Greek DMD/BMD patients with no detectable deletions. Seven patients also had severe mental retardation. Direct sequencing of samples demonstrating a shift of SSCA mobility revealed six different and pathogenic minor changes, five in DMD and one in a BMD patient. Four of the mutations were found in DMD patients,vith severe MR. Three of these mutations were localised in exon 66,,which presents an interesting similarity with part of the 3’ end of the genome of eastern equine encephalomyelitis virus (EEEV). The present data from Greek DMD/BMD patients give further information about the phenotypic effects consequent on mutations in exons at the distal part of the human dystrophin gene

Female reproductive output and potential recruitment of three fished southern king crab stocks from the Southern Atlantic Ocean

The female reproductive output and potential recruitment (PR) were studied in three Argentinean southern king crab (Lithodes santolla and Lithodes confundens) stocks: in the Beagle Channel (BC), under an artisanal fishery pressure since ; in the San Jorge Gulf (SJG), under - years industrial fishing exploitation; and off the Atlantic coast of Isla Grande de Tierra del Fuego (TDF), under current exploratory regime. After evaluating their reproductive parameters, we suggest that these fisheries pass through at least two detectable phases. The first phase, in the SJG stock, is sperm limitation evidenced by a high proportion of ovigerous females but a decreased female fecundity. A second phase, in the BC stock, shows a sustained low proportion of ovigerous females which were the largest females of this stock, along with a decreased relative abundance, which in lithodids are indicators of recruitment overfishing. Contrastingly, the TDF stock showed healthy population parameters before the opening of the exploratory fishery. The extremely low value of PR (.%) in the BC stock further reinforces that this stock is experiencing or has experienced recruitment overfishing, as a small proportion of the offspring would reach sexual maturity or achieve legal sizes.Fil: Di Salvatore, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Sacristán, Hernán Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Florentin, Olga Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Varisco, Martin Alejandro. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigaciones y Transferencia Golfo San Jorge; ArgentinaFil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

Suspended mesh-bags enclosures for Southern King Crab Lithodes santolla (Molina 1782) larvae and juvenile culture in the sea

The potential for using suspended mesh-bags for larval/juvenile southern king crab (Lithodes santolla) aquaculture was assessed. Three early stages (Zoea, Megalopa and first juvenile, or C1) were confined for 45–65 days in mesh-bags near the sea-bottom. As L. santolla starts feeding when it reaches the first juvenile stage, the effect of biofouling presence was also tested in the C1 culture. Extreme vulnerability of the first larval stage was observed, as no live larvae were recovered when Z1 were used as seeds. On the other hand, survival of Megalopa and C1 reached 19.76 ± 1.08 and 30.00 ± 3.50%, respectively, and both C1 juvenile survival and growth were enhanced significantly by the presence of biofouling on the bags. These results indicate that suspended mesh-bags have potential for L. santolla juvenile culture in the sea. We suggest a 2-step culture process: indoor culturing of the three Zoea stages, and subsequently sea culture starting at the Megalopa stage. Once Megalopa molt to the C1 stage in the field, the already fouled culture system (mesh-bags) would allow newly molted crabs to feed. Further research should be directed towards sea culture optimization, including feeding requirements for bigger crabs, to implement a future stock enhancement program for king crabs in the Beagle Channel.Fil: Sotelano, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Lovrich, Gustavo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Di Salvatore, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Florentin, Olga Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Giamportone, Ariel Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Tapella, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

How feedback inhibition shapes spike-timing-dependent plasticity and its implications for recent Schizophrenia models

It has been shown that plasticity is not a fixed property but, in fact, changes depending on the location of the synapse on the neuron and/or changes of biophysical parameters. Here we investigate how plasticity is shaped by feedback inhibition in a cortical microcircuit. We use a differential Hebbian learning rule to model spike-timing dependent plasticity and show analytically that the feedback inhibition shortens the time window for LTD during spike-timing dependent plasticity but not for LTP. We then use a realistic GENESIS model to test two hypothesis about interneuron hypofunction and conclude that a reduction in GAD67 is the most likely candidate as the cause for hypofrontality as observed in Schizophrenia