768 research outputs found
Intrarectal administration of hCG (Human Choriogonadotropin) and fat loss as assessed by Dual energy X-ray absorptiometry (DXA) in experimental animals.
Our studies suggest that in experimental animals, submitted to a hypocaloric diet, the intrarectal administration of hCG (Human Chorionic Gonadotropin) decreases body fat and increases lean mass content in relative values to a greater extent that control animals who did not receive hCG.

Identification and characterization of nursery areas of red mullet Mullus barbatus in the Central Tyrrhenian Sea
Red Mullet Mullus barbatus is an important target of fishing activities in the central Tyrrhenian Sea, so it is essential to identify its critical habitats in order to manage this resource efficiently. Our research specifically focused on the identification and characterization of nursery areas. The use of spatial interpolation techniques enabled us to identify five nurseries that were highly persistent through time. Moreover, the estimate of juvenile density confirmed the strong aggregation effect of these nursery grounds, as a great portion of young individuals were concentrated in a relatively small surface of the study area. The environmental characterization of these areas showed that juveniles were mainly distributed on bottoms with a relatively high percentage of sand (>70%; P <0.05). Shannon biodiversity index analysis indicated that the southern nurseries reached the highest values of habitat quality (P < 0.0001). Multivariate analysis showed that nursery grounds were divided into three main groups, and analysis of spatial dynamics showed that two different strategies characterized Red Mullet juveniles when density changes over time. In particular, in some areas young individuals selected habitats in a density-dependent way following the basin model scheme, while in other zones they selected habitats in a density-independent way according to the proportional density model. Results also showed that juveniles followed the proportional density model strategy into nursery areas with the highest Shannon biodiversity index values
Mapping and classification of ecologically sensitive marine habitats using unmanned aerial vehicle (UAV) imagery and object-based image analysis (OBIA)
Nowadays, emerging technologies, such as long-range transmitters, increasingly miniaturized components for positioning, and enhanced imaging sensors, have led to an upsurge in the availability of new ecological applications for remote sensing based on unmanned aerial vehicles (UAVs), sometimes referred to as “drones”. In fact, structure-from-motion (SfM) photogrammetry coupled with imagery acquired by UAVs offers a rapid and inexpensive tool to produce high-resolution orthomosaics, giving ecologists a new way for responsive, timely, and cost-effective monitoring of ecological processes. Here, we adopted a lightweight quadcopter as an aerial survey tool and object-based image analysis (OBIA) workflow to demonstrate the strength of such methods in producing very high spatial resolution maps of sensitive marine habitats. Therefore, three different coastal environments were mapped using the autonomous flight capability of a lightweight UAV equipped with a fully stabilized consumer-grade RGB digital camera. In particular we investigated a Posidonia oceanica seagrass meadow, a rocky coast with nurseries for juvenile fish, and two sandy areas showing biogenic reefs of Sabelleria alveolata. We adopted, for the first time, UAV-based raster thematic maps of these key coastal habitats, produced after OBIA classification, as a new method for fine-scale, low-cost, and time saving characterization of sensitive marine environments which may lead to a more effective and efficient monitoring and management of natural resource
La sucesiĂłn intestada en la reforma del CĂłdigo Civil
Fil: Belluscio, Augusto César. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Civil V. Buenos Aires, Argentin
La especialidad del régimen de nulidades matrimoniales
Fil: Belluscio, Augusto César. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Civil V. Buenos Aires, Argentin
La legĂtima en la reforma del CĂłdigo Civil
Fil: Belluscio, Augusto César. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Civil V. Buenos Aires, Argentin
El pensamiento finalista como obstáculo epistemológico para la enseñanza del modelo darwiniano
En este trabajo presentamos evidencias que apoyan la hipĂłtesis segĂşn la cual el pensamiento finalista funciona como un obstáculo para el aprendizaje del modelo darwiniano. Estas evidencias provienen de la indagaciĂłn de las concepciones de los estudiantes, la puesta en práctica de una unidad didáctica centrada en la superaciĂłn de este obstáculo y el análisis epistemolĂłgico del modelo cientĂfico
Transcranial Electric Stimulation Entrains Cortical Neuronal Populations in Rats
Low intensity electric fields have been suggested to affect the ongoing neuronal activity in vitro and in human studies. However, the physiological mechanism of how weak electrical fields affect and interact with intact brain activity is not well understood. We performed in vivo extracellular and intracellular recordings from the neocortex and hippocampus of anesthetized rats and extracellular recordings in behaving rats. Electric fields were generated by sinusoid patterns at slow frequency (0.8, 1.25 or 1.7 Hz) via electrodes placed on the surface of the skull or the dura. Transcranial electric stimulation (TES) reliably entrained neurons in widespread cortical areas, including the hippocampus. The percentage of TES phase-locked neurons increased with stimulus intensity and depended on the behavioral state of the animal. TES-induced voltage gradient, as low as 1 mV/mm at the recording sites, was sufficient to phase-bias neuronal spiking. Intracellular recordings showed that both spiking and subthreshold activity were under the combined influence of TES forced fields and network activity. We suggest that TES in chronic preparations may be used for experimental and therapeutic control of brain activity
Multielectrode Recordings From Identified Neurons Involved in Visually Elicited Escape Behavior
A major challenge in current neuroscience is to understand the concerted functioning of distinct neurons involved in a particular behavior. This goal first requires achieving an adequate characterization of the behavior as well as an identification of the key neuronal elements associated with that action. Such conditions have been considerably attained for the escape response to visual stimuli in the crab Neohelice. During the last two decades a combination of in vivo intracellular recordings and staining with behavioral experiments and modeling, led us to postulate that a microcircuit formed by four classes of identified lobula giant (LG) neurons operates as a decision-making node for several important visually-guided components of the crab’s escape behavior. However, these studies were done by recording LG neurons individually. To investigate the combined operations performed by the group of LG neurons, we began to use multielectrode recordings. Here we describe the methodology and show results of simultaneously recorded activity from different lobula elements. The different LG classes can be distinguished by their differential responses to particular visual stimuli. By comparing the response profiles of extracellular recorded units with intracellular recorded responses to the same stimuli, two of the four LG classes could be faithfully recognized. Additionally, we recorded units with stimulus preferences different from those exhibited by the LG neurons. Among these, we found units sensitive to optic flow with marked directional preference. Units classified within a single group according to their response profiles exhibited similar spike waveforms and similar auto-correlograms, but which, on the other hand, differed from those of groups with different response profiles. Additionally, cross-correlograms revealed excitatory as well as inhibitory relationships between recognizable units. Thus, the extracellular multielectrode methodology allowed us to stably record from previously identified neurons as well as from undescribed elements of the brain of the crab. Moreover, simultaneous multiunit recording allowed beginning to disclose the connections between central elements of the visual circuits. This work provides an entry point into studying the neural networks underlying the control of visually guided behaviors in the crab brain.Fil: Cámera, Alejandro Gabriel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; ArgentinaFil: Belluscio, Mariano Andres. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Tomsic, Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentin
Retos para el futuro de los alimentos
En una entrevista exclusiva con la Revista RIA, la doctora en bioquĂmica [Raquel Chan] habla sobre la importancia de la investigaciĂłn en materia de cultivos mejorados y su impacto en la producciĂłn de alimentos.Gerencia de ComunicaciĂłn e Imagen InstitucionalFil: Belluscio, Ana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Area de DivulgaciĂłn CientĂfica; Argentin
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