359 research outputs found

    Motor interference in interactive contexts

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    Action observation and execution share overlapping neural substrates, so that simultaneous activation by observation and execution modulates motor performance. Previous literature on simple prehension tasks has revealed that motor influence can be two-sided: facilitation for observed and performed congruent actions and interference for incongruent actions. But little is known of the specific modulations of motor performance in complex forms of interaction. Is it possible that the very same observed movement can lead either to interference or facilitation effects on a temporally overlapping congruent executed action, depending on the context? To answer this question participants were asked to perform a reach-to-grasp movement adopting a precision grip (PG) while: (i) observing a fixation cross, (ii) observing an actor performing a PG with interactive purposes, (iii) observing an actor performing a PG without interactive purposes. In particular, in the interactive condition the actor was shown trying to pour some sugar on a large cup located out of her reach but close to the participant watching the video, thus eliciting in reaction a complementary whole-hand grasp. Notably, fine-grained kinematic analysis for this condition revealed a specific delay in the grasping and reaching components and an increased trajectory deviation despite the observed and executed movement’s congruency. Moreover, early peaks of trajectory deviation seem to indicate that socially relevant stimuli are acknowledged by the motor system very early. These data suggest that interactive contexts can determine a prompt modulation of stimulus–response compatibility effects

    The multiform motor cortical output: kinematic, predictive and response coding

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    Observing actions performed by others entails a subliminal activation of primary motor cortex reflecting the components encoded in the observed action. One of the most debated issues concerns the role of this output: Is it a mere replica of the incoming flow of information (kinematic coding), is it oriented to anticipate the forthcoming events (predictive coding) or is it aimed at responding in a suitable fashion to the actions of others (response coding)? The aim of the present study was to disentangle the relative contribution of these three levels and unify them into an integrated view of cortical motor coding. We combined transcranial magnetic stimulation (TMS) and electromyography recordings at different timings to probe the excitability of corticospinal projections to upper and lower limb muscles of participants observing a soccer player performing: (i) a penalty kick straight in their direction and then coming to a full stop, (ii) a penalty kick straight in their direction and then continuing to run, (iii) a penalty kick to the side and then continuing to run. The results show a modulation of the observer's corticospinal excitability in different effectors at different times reflecting a multiplicity of motor coding. The internal replica of the observed action, the predictive activation, and the adaptive integration of congruent and non-congruent responses to the actions of others can coexist in a not mutually exclusive way. Such a view offers reconciliation among different (and apparently divergent) frameworks in action observation literature, and will promote a more complete and integrated understanding of recent findings on motor simulation, motor resonance and automatic imitation

    VST - VLT Survey Telescope Integration Status

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    The VLT Survey Telescope (VST) is a 2.6m aperture, wide field, UV to I facility, to be installed at the European Southern Observatory (ESO) on the Cerro Paranal Chile. VST was primarily intended to complement the observing capabilities of VLT with wide-angle imaging for detecting and pre-characterising sources for further observations with the VLT.Comment: 2 pages, 2 figures, conferenc

    Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle

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    The origin of vertebrate paired appendages is one of the most investigated and debated examples of evolutionary novelty. Paired appendages are widely considered key innovations that allowed new opportunities for controlled swimming and gill ventilation and were prerequisites for the eventual transition from water to land. The last 150 years of debate has been shaped by two contentious theories: the ventrolateral fin-fold hypothesis and the archipterygium hypothesis. The latter proposes that fins and girdles evolved from an ancestral gill arch. Although tantalizing developmental evidence has revived interest in this idea, it is apparently unsupported by fossil evidence. Here we present fossil evidence of a pharyngeal basis for the vertebrate shoulder girdle. We use CT scanning to reveal details of the braincase of Kolymaspis sibirica, a placoderm fish from the Early Devonian of Siberia that suggests a pharyngeal component of the shoulder. We combine these findings with refreshed comparative anatomy of placoderms and jawless outgroups to place the origin of the shoulder girdle on the sixth branchial arch. These findings provide a novel framework for understanding the origin of the pectoral girdle. Our new evidence clarifies the location of the presumptive head-trunk interface in jawless fishes and explains the constraint on branchial arch number in gnathostomes. The results revive a key aspect of the archipterygium hypothesis, but also reconciles it with the ventrolateral fin fold model

    The Vallo di Diano Range-Bounding Fault-System (Southern Italy): New Evidence of Recent Activity From High-Resolution Seismic Profiling

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    The Vallo di Diano is the largest intermountain basin in the Southern Apennines (Italy). The basin evolution was controlled by the Quaternary activity of a range-bounding, SW-dipping normal fault system located to the east (Vallo di Diano Fault System, VDFS). Geological and oil industry data define the sin-sedimentary activity of the VDFS up to the Middle Pleistocene. However, commercial profiles do not resolve the shallower, eastern portion of the basin, due to strong lateral heterogeneities and unfavourable surface conditions. Therefore, Late Pleistocene-Holocene activity of the VDFS and its seismogenic potential are still uncertain. To better constrain the shallow structure of the basin, we performed four high-resolution seismic surveys, along its eastern side, where slope breccias and fans cover the Mesozoic carbonate bedrock and bury the VDFS. We also investigated some NW-trending flexures affecting Late Pleistocene fans, that we had previously detected and dubitatively ascribed to recent faulting. Seismic data were acquired with a dense wide-aperture geometry. Two high-resolution (HR) NE-trending profiles, about 1.5 km long, were collected using respectively 5 m and 10 m spaced receivers and sources. Two very high-resolution (VHR) NE-trending profiles, 400 and 350 m long, with densely spaced sources (4 m) and receivers (2 m) were also collected. HR profiling was aimed at imaging alluvial fan thickness and morphology of the underlying carbonate bedrock. VHR surveys targeted the flexures and their possible origin. All lines were acquired with a HR vibroseis source, except for the shortest profile, where we used a buffalo-gun, better suited for very near-surface imaging (z < 50 m depth). Seismic imaging consists of reflectivity images obtained by CDP-processing of reflection data complemented by Vp images obtained by multi-scale seismic tomography. The stack sections illuminated the basin down to 0.4-0.5 s TWT and reveal an array of high-angle, generally SW-dipping faults dissecting the bedrock and the alluvial fans. Faulting created accommodation space in the hanging-wall and displaced the different fan generations. Clear reflection truncations in the stack-sections correspond to significant Vp lateral changes in the tomographic images. VHR tomography is well defined along the shortest line down to 40 m depth, where two steps within slope breccias are visible. Moreover, two low-velocity wedges (colluvial packages) are imaged in the near surface (5-20 m depth). These data support recent faulting consistently with surface geomorphic features. We interpret these fault structures as splays of the range bounding master fault. Comparison with commercial reflection profiles nearby reveals a great improvement in seismic imaging achieved by HR surveys, which allow a detailed seismostratigraphic analysis of the basin.UnpublishedSan Francisco (CA), Moscone West, Howard Street3.2. Tettonica attivaope

    The Vallo di Diano Range-Bounding Fault-System (Southern Italy): New Evidence of Recent Activity From High-Resolution Seismic Profiling

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    The Vallo di Diano is the largest intermountain basin in the Southern Apennines (Italy). The basin evolution was controlled by the Quaternary activity of a range-bounding, SW-dipping normal fault system located to the east (Vallo di Diano Fault System, VDFS). Geological and oil industry data define the sin-sedimentary activity of the VDFS up to the Middle Pleistocene. However, commercial profiles do not resolve the shallower, eastern portion of the basin, due to strong lateral heterogeneities and unfavourable surface conditions. Therefore, Late Pleistocene-Holocene activity of the VDFS and its seismogenic potential are still uncertain. To better constrain the shallow structure of the basin, we performed four high-resolution seismic surveys, along its eastern side, where slope breccias and fans cover the Mesozoic carbonate bedrock and bury the VDFS. We also investigated some NW-trending flexures affecting Late Pleistocene fans, that we had previously detected and dubitatively ascribed to recent faulting. Seismic data were acquired with a dense wide-aperture geometry. Two high-resolution (HR) NE-trending profiles, about 1.5 km long, were collected using respectively 5 m and 10 m spaced receivers and sources. Two very high-resolution (VHR) NE-trending profiles, 400 and 350 m long, with densely spaced sources (4 m) and receivers (2 m) were also collected. HR profiling was aimed at imaging alluvial fan thickness and morphology of the underlying carbonate bedrock. VHR surveys targeted the flexures and their possible origin. All lines were acquired with a HR vibroseis source, except for the shortest profile, where we used a buffalo-gun, better suited for very near-surface imaging (z < 50 m depth). Seismic imaging consists of reflectivity images obtained by CDP-processing of reflection data complemented by Vp images obtained by multi-scale seismic tomography. The stack sections illuminated the basin down to 0.4-0.5 s TWT and reveal an array of high-angle, generally SW-dipping faults dissecting the bedrock and the alluvial fans. Faulting created accommodation space in the hanging-wall and displaced the different fan generations. Clear reflection truncations in the stack-sections correspond to significant Vp lateral changes in the tomographic images. VHR tomography is well defined along the shortest line down to 40 m depth, where two steps within slope breccias are visible. Moreover, two low-velocity wedges (colluvial packages) are imaged in the near surface (5-20 m depth). These data support recent faulting consistently with surface geomorphic features. We interpret these fault structures as splays of the range bounding master fault. Comparison with commercial reflection profiles nearby reveals a great improvement in seismic imaging achieved by HR surveys, which allow a detailed seismostratigraphic analysis of the basin

    Oculomotor interference during manual response preparation: evidence from the response-cueing paradigm

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    Preparation provided by visual location cues is known to speed up behavior. However, the role of concurrent saccades in response to visual cues remains unclear. In this study, participants performed a spatial precueing task by pressing one of four response keys with one of four fingers (two of each hand) while eye movements were monitored. Prior to the stimulus, we presented a neutral cue (baseline), a hand cue (corresponding to left vs. right positions), or a finger cue (corresponding to inner vs. outer positions). Participants either remained fixated on a central fixation point or moved their eyes freely. The results demonstrated that saccades during the cueing interval altered the pattern of cueing effects. Finger cueing trials in which saccades were spatially incompatible (vs. compatible) with the subsequently required manual response exhibited slower manual RTs. We propose that interference between saccades and manual responses affects manual motor preparation

    Lentiviral gene therapy corrects platelet phenotype and function in patients with Wiskott-Aldrich syndrome

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    BACKGROUND: Thrombocytopenia is a serious issue for all patients with classical Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) because it causes severe and life-threatening bleeding. Lentiviral gene therapy (GT) for WAS has shown promising results in terms of immune reconstitution. However, despite the reduced severity and frequency of bleeding events, platelet counts remain low in GT-treated patients. OBJECTIVE: We carefully investigated platelet defects in terms of phenotype and function in untreated patients with WAS and assessed the effect of GT treatment on platelet dysfunction. METHODS: We analyzed a cohort of 20 patients with WAS/XLT, 15 of them receiving GT. Platelet phenotype and function were analyzed by using electron microscopy, flow cytometry, and an aggregation assay. Platelet protein composition was assessed before and after GT by means of proteomic profile analysis. RESULTS: We show that platelets from untreated patients with WAS have reduced size, abnormal ultrastructure, and a hyperactivated phenotype at steady state, whereas activation and aggregation responses to agonists are decreased. GT restores platelet size and function early after treatment and reduces the hyperactivated phenotype proportionally to WAS protein expression and length of follow-up. CONCLUSIONS: Our study highlights the coexistence of morphologic and multiple functional defects in platelets lacking WAS protein and demonstrates that GT normalizes the platelet proteomic profile with consequent restoration of platelet ultrastructure and phenotype, which might explain the observed reduction of bleeding episodes after GT. These results are instrumental also from the perspective of a future clinical trial in patients with XLT only presenting with microthrombocytopenia

    B-cell reconstitution after lentiviral vector-mediated gene therapy in patients with Wiskott-Aldrich syndrome

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    Background Wiskott-Aldrich syndrome (WAS) is a severe X-linked immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, and susceptibility to autoimmunity and lymphomas. Hematopoietic stem cell transplantation is the treatment of choice; however, administration of WAS gene-corrected autologous hematopoietic stem cells has been demonstrated as a feasible alternative therapeutic approach. Objective Because B-cell homeostasis is perturbed in patients with WAS and restoration of immune competence is one of the main therapeutic goals, we have evaluated reconstitution of the B-cell compartment in 4 patients who received autologous hematopoietic stem cells transduced with lentiviral vector after a reduced-intensity conditioning regimen combined with anti-CD20 administration. Methods We evaluated B-cell counts, B-cell subset distribution, B cell-activating factor and immunoglobulin levels, and autoantibody production before and after gene therapy (GT). WAS gene transfer in B cells was assessed by measuring vector copy numbers and expression of Wiskott-Aldrich syndrome protein. Results After lentiviral vector-mediated GT, the number of transduced B cells progressively increased in the peripheral blood of all patients. Lentiviral vector-transduced progenitor cells were able to repopulate the B-cell compartment with a normal distribution of B-cell subsets both in bone marrow and the periphery, showing a WAS protein expression profile similar to that of healthy donors. In addition, after GT, we observed a normalized frequency of autoimmune-associated CD19+CD21-CD35- and CD21low
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