Nonlinear Processing of Shape Information in Rat Lateral Extrastriate Cortex

In rodents, the progression of extrastriate areas located laterally to primary visual cortex (V1) has been assigned to a putative object-processing pathway (homologous to the primate ventral stream), based on anatomical considerations. Recently, we found functional support for such attribution (Tafazoli et al., 2017), by showing that this cortical progression is specialized for coding object identity despite view changes, the hallmark property of a ventral-like pathway. Here, we sought to clarify what computations are at the base of such specialization. To this aim, we performed multielectrode recordings from V1 and laterolateral area LL (at the apex of the putative ventral-like hierarchy) of male adult rats, during the presentation of drifting gratings and noise movies. We found that the extent to which neuronal responses were entrained to the phase of the gratings sharply dropped from V1 to LL, along with the quality of the receptive fields inferred through reverse correlation. Concomitantly, the tendency of neurons to respond to different oriented gratings increased, whereas the sharpness of orientation tuning declined. Critically, these trends are consistent with the nonlinear summation of visual inputs that is expected to take place along the ventral stream, according to the predictions of hierarchical models of ventral computations and a meta-analysis of the monkey literature. This suggests an intriguing homology between the mechanisms responsible for building up shape selectivity and transformation tolerance in the visual cortex of primates and rodents, reasserting the potential of the latter as models to investigate ventral stream functions at the circuitry level.SIGNIFICANCE STATEMENT Despite the growing popularity of rodents as models of visual functions, it remains unclear whether their visual cortex contains specialized modules for processing shape information. To addresses this question, we compared how neuronal tuning evolves from rat primary visual cortex (V1) to a downstream visual cortical region (area LL) that previous work has implicated in shape processing. In our experiments, LL neurons displayed a stronger tendency to respond to drifting gratings with different orientations while maintaining a sustained response across the whole duration of the drift cycle. These trends match the increased complexity of pattern selectivity and the augmented tolerance to stimulus translation found in monkey visual temporal cortex, thus revealing a homology between shape processing in rodents and primates

Platelets and extra-corporeal membrane oxygenation in adult patients: a systematic review and meta-analysis

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peri procedural thrombocytopenia after aortic bioprosthesis implant a systematic review and meta analysis comparison among conventional stentless rapid deployment and transcatheter valves

Abstract Background Thrombocytopenia has been shown to occur soon after surgical biological aortic valve replacement (AVR), and recently reported also after transcatheter valve implantation (TAVI). The mechanism underlying this phenomenon is still unknown, and its clinical impact on the peri-operative outcome has been poorly investigated. Methods A systematic review and a meta-analysis of all available studies reporting data about peri-procedural thrombocytopenia on isolated bio-AVR, comparing rapid-deployment (RDV), stentless (stentless-AVR), and TAVI vs. stented (stented-AVR) valves, have been performed. Results Fifteen trials (2.163 patients) were included in the meta-analysis. Perioperative platelet reduction ranged from 35% to 55% in stented-AVR, from 60% to 77% in stentless-AVR, from 53% to 60% in RDV, and from to 21% to 72% in TAVI (apparently, balloon-expandable valves more frequently associated to thrombocytopenia). Stented-AVR required more red blood cells transfusion than stentless-AVR (P  Conclusions Thrombocytopenia-related major adverse events were mainly reported in TAVI patients, whereas clinically meaningless in surgical patients. Transient peri-procedural thrombocytopenia is common after bio-AVR, regardless of prosthesis's type or implant modality. It should receive appropriate monitoring and focused investigations

sutured and sutureless repair of postinfarction left ventricular free wall rupture a systematic review

Summary Postinfarction left ventricular free-wall rupture is a potentially catastrophic event. Emergency surgical intervention is almost invariably required, but the most appropriate surgical procedure remains controversial. A systematic review, from 1993 onwards, of all available reports in the literature about patients undergoing sutured or sutureless repair of postinfarction left ventricular free-wall rupture was performed. Twenty-five studies were selected, with a total of 209 patients analysed. Sutured repair was used in 55.5% of cases, and sutureless repair in the remaining cases. Postoperative in-hospital mortality was 13.8% in the sutured group, while it was 14% in the sutureless group. A trend towards a higher rate of in-hospital rerupture was observed in the sutureless technique. The most common cause of in-hospital mortality (44%) was low cardiac output syndrome. In conclusion, sutured and sutureless repair for postinfarction left ventricular free-wall rupture showed comparable in-hospital mortality. However, because of the limited number of patients and the variability of surgical strategies in each reported series, further studies are required to provide more consistent data and lines of evidence

FDG PET/CT Response Evaluation in Malignant Pleural Mesothelioma Patients Treated with Talc Pleurodesis and Chemotherapy

Purpose: Talc pleurodesis (TP) is employed worldwide for the management of persistent pneumothorax or pleural effusion, particularly of malignant origin. However, there are very little available data on 18F-fluorodeoxyglucose positron-emission tomography/computed tomography (18F FDG PET/CT) response evaluation in malignant pleural mesothelioma (MPM) patients treated with TP and chemotherapy

A longitudinal analysis of the Italian national standardized mathematics tests

This paper presents a longitudinal analysis of the outcomes of the Italian national standardized mathematics tests. By intertwining quantitative and qualitative methods, we selected and analysed a set of linked questions among the tests administered to the same cohort of students first in grade 6 and then in grade 8. In particular, we focus on poor knowledge students and we argue an example of the analysis of two linked questions about graphical representation of fractions. The comparison between the two questions allows us to interpret some difficulties of students and to expect possible future behaviours