18 research outputs found

    A deep neural network model of the primate superior colliculus for emotion recognition

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    Although sensory processing is pivotal to nearly every theory of emotion, the evaluation of the visual input as ‘emotional’ (e.g. a smile as signalling happiness) has been traditionally assumed to take place in supramodal ‘limbic’ brain regions. Accordingly, subcortical structures of ancient evolutionary origin that receive direct input from the retina, such as the superior colliculus (SC), are traditionally conceptualized as passive relay centres. However, mounting evidence suggests that the SC is endowed with the necessary infrastructure and computational capabilities for the innate recognition and initial categorization of emotionally salient features from retinal information. Here, we built a neurobiologically inspired convolutional deep neural network (DNN) model that approximates physiological, anatomical and connectional properties of the retino-collicular circuit. This enabled us to characterize and isolate the initial computations and discriminations that the DNN model of the SC can perform on facial expressions, based uniquely on the information it directly receives from the virtual retina. Trained to discriminate facial expressions of basic emotions, our model matches human error patterns and above chance, yet suboptimal, classification accuracy analogous to that reported in patients with V1 damage, who rely on retino-collicular pathways for non-conscious vision of emotional attributes. When presented with gratings of different spatial frequencies and orientations never ‘seen’ before, the SC model exhibits spontaneous tuning to low spatial frequencies and reduced orientation discrimination, as can be expected from the prevalence of the magnocellular (M) over parvocellular (P) projections. Likewise, face manipulation that biases processing towards the M or P pathway affects expression recognition in the SC model accordingly, an effect that dovetails with variations of activity in the human SC purposely measured with ultra-high field functional magnetic resonance imaging. Lastly, the DNN generates saliency maps and extracts visual features, demonstrating that certain face parts, like the mouth or the eyes, provide higher discriminative information than other parts as a function of emotional expressions like happiness and sadness. The present findings support the contention that the SC possesses the necessary infrastructure to analyse the visual features that define facial emotional stimuli also without additional processing stages in the visual cortex or in ‘limbic’ areas

    Proteomics Reveals Novel Oxidative and Glycolytic Mechanisms in Type 1 Diabetic Patients' Skin Which Are Normalized by Kidney-Pancreas Transplantation

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    Background: In type 1 diabetes (T1D) vascular complications such as accelerated atherosclerosis and diffused macro-/microangiopathy are linked to chronic hyperglycemia with a mechanism that is not yet well understood. End-stage renal disease (ESRD) worsens most diabetic complications, particularly, the risk of morbidity and mortality from cardiovascular disease is increased several fold. Methods and Findings: We evaluated protein regulation and expression in skin biopsies obtained from T1D patients with and without ESRD, to identify pathways of persistent cellular changes linked to diabetic vascular disease. We therefore examined pathways that may be normalized by restoration of normoglycemia with kidney-pancreas (KP) transplantation. Using proteomic and ultrastructural approaches, multiple alterations in the expression of proteins involved in oxidative stress (catalase, superoxide dismutase 1, Hsp27, Hsp60, ATP synthase δ chain, and flavin reductase), aerobic and anaerobic glycolysis (ACBP, pyruvate kinase muscle isozyme, and phosphoglycerate kinase 1), and intracellular signaling (stratifin-14-3-3, S100-calcyclin, cathepsin, and PPI rotamase) as well as endothelial vascular abnormalities were identified in T1D and T1D+ESRD patients. These abnormalities were reversed after KP transplant. Increased plasma levels of malondialdehyde were observed in T1D and T1D+ESRD patients, confirming increased oxidative stress which was normalized after KP transplant. Conclusions: Our data suggests persistent cellular changes of anti-oxidative machinery and of aerobic/anaerobic glycolysis are present in T1D and T1D+ESRD patients, and these abnormalities may play a key role in the pathogenesis of hyperglycemia-related vascular complications. Restoration of normoglycemia and removal of uremia with KP transplant can correct these abnormalities. Some of these identified pathways may become potential therapeutic targets for a new generation of drugs

    Notulae to the Italian native vascular flora: 10

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    In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations, exclusions, and status changes to the Italian administrative regions for taxa in the genera Artemisia, Chaetonychia, Cirsium, Cynanchum, Genista, Hieracium, Iberis, Melica, Misopates, Myosotis, Thalictrum, Trifolium, Utricularia, Veronica, and Vicia. Nomenclatural and distribution updates, published elsewhere, and corrigenda are provided as supplementary material

    Accelerated endothelial wound healing on microstructured substrates under flow

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    Understanding and accelerating the mechanisms of endothelial wound healing is of fundamental interest for biotechnology and of significant medical utility in repairing pathologic changes to the vasculature induced by invasive medical interventions. We report the fundamental mechanisms that determine the influence of substrate topography and flow on the efficiency of endothelial regeneration. We exposed endothelial monolayers, grown on topographically engineered substrates (gratings), to controlled levels of flow-induced shear stress. The wound healing dynamics were recorded and analyzed in various configurations, defined by the relative orientation of an inflicted wound, the topography and the flow direction. Under flow perpendicular to the wound, the speed of endothelial regeneration was significantly increased on substrates with gratings oriented in the direction of the flow when compared to flat substrates. This behavior is linked to the dynamic state of cell-to-cell adhesions in the monolayer. In particular, interactions with the substrate topography counteract Vascular Endothelial Cadherin phosphorylation induced by the flow and the wounding. This effect contributes to modulating the mechanical connection between migrating cells to an optimal level, increasing their coordination and resulting in coherent cell motility and preservation of the monolayer integrity, thus accelerating wound healing. We further demonstrate that the reduction of vascular endothelial cadherin phosphorylation, through specific inhibition of Src activity, enhances endothelial wound healing in flows over flat substrates

    Consensus Statement of the Italian Polispecialistic Society of Young Surgeons (SPIGC): Diagnosis and Treatment of Acute Appendicitis

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    Background Acute appendicitis (AA) is one of the most common causes of abdominal pain requiring surgical intervention. Approximately 20% of AA cases are characterized by complications such as gangrene, abscesses, perforation, or diffuse peritonitis, which increase patients’ morbidity and mortality. Diagnosis of AA can be difficult, and evaluation of clinical signs, laboratory index and imaging should be part of the management of patients with suspicion of AA. Methods This consensus statement was written in relation to the most recent evidence for diagnosis and treatment of AA, performing a literature review on the most largely adopted scientific sources. The members of the SPIGC (Italian Polispecialistic Society of Young Surgeons) worked jointly to draft it. The recommendations were defined and graded based on the current levels of evidence and in accordance with the criteria adopted by the American College of Chest Physicians (CHEST) for the strength of the recommendations. Results Fever and migratory pain tend to be present in patients with suspicion of AA. Laboratory and radiological examinations are commonly employed in the clinical practice, but today also scoring systems based on clinical signs and laboratory data have slowly been adopted for diagnostic purpose. The clinical presentation of AA in children, pregnant and elderly patients can be unusual, leading to more difficult and delayed diagnosis. Surgery is the best option in case of complicated AA, whereas it is not mandatory in case of uncomplicated AA. Laparoscopic surgical treatment is feasible and recommended. Postoperative antibiotic treatment is recommended only in patients with complicated AA

    Clinical competence in the surgery of rectal cancer: The Italian Consensus Conference

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    BACKGROUND AND AIM: The literature continues to emphasize the advantages of treating patients in "high volume" units by "expert" surgeons, but there is no agreed definition of what is meant by either term. In September 2012, a Consensus Conference on Clinical Competence was organized in Rome as part of the meeting of the National Congress of Italian Surgery (I Congresso Nazionale della Chirurgia Italiana: Unità e valore della chirurgia italiana). The aims were to provide a definition of "expert surgeon" and "high-volume facility" in rectal cancer surgery and to assess their influence on patient outcome. METHOD: An Organizing Committee (OC), a Scientific Committee (SC), a Group of Experts (E) and a Panel/Jury (P) were set up for the conduct of the Consensus Conference. Review of the literature focused on three main questions including training, "measuring" of quality and to what extent hospital and surgeon volume affects sphincter-preserving procedures, local recurrence, 30-day morbidity and mortality, survival, function, choice of laparoscopic approach and the choice of transanal endoscopic microsurgery (TEM). RESULTS AND CONCLUSION: The difficulties encountered in defining competence in rectal surgery arise from the great heterogeneity of the parameters described in the literature to quantify it. Acquisition of data is difficult as many articles were published many years ago. Even with a focus on surgeon and hospital volume, it is difficult to define their role owing to the variability and the quality of the relevant studies
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