122 research outputs found

    Covert preparation of a manual response in a ‘go’/‘no-go’ saccadic task is driven by execution of the eye movement and not by visual stimulus occurrence.

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    It has been recently demonstrated that visually guided saccades are linked to changes in muscle excitability in the relaxed upper limb, which are compatible with a covert motor plan encoding a hand movement toward the gaze target. In this study we investigated whether these excitability changes are time locked to the visual stimulus, as predicted by influential attention models, or are strictly dependent on saccade execution. Single-pulse transcranial magnetic stimulation was applied to the motor cortex at eight different time delays during a ’go’/’no-go’ task, which involved overt or covert orienting of attention. By analyzing the time course of excitability in three hand muscles, synchronized with the onset of either the attentional cue or the eye movement, we demonstrated that side- and muscle-specific excitability changes were strictly time locked to the saccadic response and were not correlated to the onset of the visual attentive stimulus. Furthermore, muscle excitability changes were absent following a covert shift of attention. We conclude that a sub-threshold manual motor plan is automatically activated by the saccade decision-making process, as part of a covert eye-hand coordination program. We found no evidence for a representation of spatial attention within the upper limb motor map

    Dynamic Changes in Upper-Limb Corticospinal Excitability during a 'Pro-/Anti-saccade' Double-Choice Task

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    Under natural behavioral conditions, visually guided eye movements are linked to direction-specific modulations of cortico-spinal system (CSS) excitability in upper-limb muscles, even in absence of a manual response. These excitability changes have been shown to be compatible with a covert motor program encoding a manual movement toward the same target of the eyes. The aim of this study is to investigate whether this implicit oculo-manual coupling is enforced following every saccade execution or it depends on the behavioral context. Twenty-two healthy young adults participated in the study. Single-pulse transcranial magnetic stimulation was applied to the motor cortex at nine different time epochs during a double-choice eye task, in which the decision to execute a prosaccade or an antisaccade was made on the color of a peripheral visual cue. By analyzing the amplitude of the motor evoked potentials (MEP) in three distal muscles of the resting upper-limb, a facilitation peak of CSS excitability was found in two of them at 120 ms before the eyes begin to move. Furthermore, a long-lasting, generalized reduced corticomotor excitability develops following the eye response. Finally, a quite large modulation of MEP amplitude, depending on the direction of the saccade, is observed only in the first dorsal interosseous muscle, in a narrow time window at about 150 ms before the eye movement, irrespective of the type of the ocular response (pro-/anti-saccade). This change in CSS excitability is not tied up to the timing of the occurrence of the visual cue but, instead, appears to be tightly time-related to the saccade onset. Observed excitability changes differ in many respects from those previously reported with different behavioral paradigms. A main finding of our study is that the implicit coupling between eye and hand motor systems is contingent upon the particular motor set determined by the cognitive aspects of the performed oculomotor task. In particular, the direction-specific modulation in CSS excitability described in this study appears to be related to perceptual and decision-making processes rather than representing an implicit upper-limb motor program, coupled to the saccade execution

    Covert preparation of a manual response in a ‘go’/‘no-go’ saccadic task is driven by execution of the eye movement and not by visual stimulus occurrence.

    Get PDF
    It has been recently demonstrated that visually guided saccades are linked to changes in muscle excitability in the relaxed upper limb, which are compatible with a covert motor plan encoding a hand movement toward the gaze target. In this study we investigated whether these excitability changes are time locked to the visual stimulus, as predicted by influential attention models, or are strictly dependent on saccade execution. Single-pulse transcranial magnetic stimulation was applied to the motor cortex at eight different time delays during a ’go’/’no-go’ task, which involved overt or covert orienting of attention. By analyzing the time course of excitability in three hand muscles, synchronized with the onset of either the attentional cue or the eye movement, we demonstrated that side- and muscle-specific excitability changes were strictly time locked to the saccadic response and were not correlated to the onset of the visual attentive stimulus. Furthermore, muscle excitability changes were absent following a covert shift of attention. We conclude that a sub-threshold manual motor plan is automatically activated by the saccade decision-making process, as part of a covert eye-hand coordination program. We found no evidence for a representation of spatial attention within the upper limb motor map

    Genotype-phenotype correlation study in 364 osteogenesis imperfecta Italian patients

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    Osteogenesis imperfecta (OI) is a rare genetic disorder of the connective tissue and 90% of cases are due to dominant mutations in COL1A1 and COL1A2 genes. To increase OI disease knowledge and contribute to patient follow-up management, a homogeneous Italian cohort of 364 subjects affected by OI types I-IV was evaluated. The study population was composed of 262 OI type I, 24 type II, 39 type III, and 39 type IV patients. Three hundred and nine subjects had a type I collagen affecting function mutations (230 in α1(I) and 79 in α2(I)); no disease-causing changes were noticed in 55 patients. Compared with previous genotype-phenotype OI correlation studies, additional observations arose: a new effect for α1- and α2-serine substitutions has been pointed out and heart defects, never considered before, resulted associated to quantitative mutations (P = 0.043). Moreover, some different findings emerged if compared with previous literature; especially, focusing the attention on the lethal form, no association with specific collagen regions was found and most of variants localized in the previously reported "lethal clusters" were causative of OI types I-IV. Some discrepancies have been highlighted also considering the "50-55 nucleotides rule," as well as the relationship between specific collagen I mutated region and the presence of dentinogenesis imperfecta and/or blue sclera. Despite difficulties still present in defining clear rules to predict the clinical outcome in OI patients, this study provides new pieces for completing the puzzle, also thanks to the inclusion of clinical signs never considered before and to the large number of OI Italian patients

    The COVID-19 Pandemic and Its Implications for Rural Economies

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    This paper presents a rapid assessment of current and likely future impacts of the COVID-19 outbreak on rural economies given their socio-economic characteristics. Drawing principally on current evidence for the UK, as well as lessons from the 2001 Foot and Mouth Disease outbreak and the 2007/8 financial crises, it outlines the likely key demand and supply effects, paying attention to the situation for agriculture as well as discussing the implications for rural communities. A distinction is made between the effects on businesses offering goods and services for out-of-home as opposed to in-home consumption. Gendered dimensions are also noted as likely business and household strategies for coping and adaptation. The paper concludes with a brief mapping of a research agenda for studying the longer-term effects of COVID-19 on rural economies

    COL1-Related Disorders: Case Report and Review of Overlapping Syndromes

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    Collagen type I mutations are related to wide phenotypic expressions frequently causing an overlap of clinical manifestations, in particular between Osteogenesis Imperfecta (OI) and Ehlers-Danlos syndrome (EDS). Both disorders present inter- and intra-familial clinical variability and several clinical signs are present in both diseases. Recently, after the observation that some individuals first ascertained by a suspicion of EDS resulted then carriers of pathogenic variants of genes known to primarily cause OI, some authors proposed the term “COL1-related overlap disorder” to describe these cases. In this paper, we report clinical, molecular, and biochemical information about an individual with a diagnosis of EDS with severe joint hypermobility who carries a pathogenic heterozygous variant in COL1A2 gene, and a benign variant in COL1A1 gene. The pathogenic variant, commonly ascribed to OI, as well as the benign variant, has been inherited from the individual's mother, who presented only mild signs of OI and the diagnosis of OI was confirmed only after molecular testing. In addition, we reviewed the literature of similar cases of overlapping syndromes caused by COL1 gene mutations. The reported case and the literature review suggest that the COL1-related overlap disorders (OI, EDS and overlapping syndromes) represent a continuum of clinical phenotypes related to collagen type I mutations. The spectrum of COL1-related clinical manifestations, the pathophysiology and the underlying molecular mechanisms support the adoption of the updated proposed term “COL1-related overlap disorder” to describe the overlapping syndromes

    Cytochalasin B Modulates Nanomechanical Patterning and Fate in Human Adipose-Derived Stem Cells

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    Cytoskeletal proteins provide architectural and signaling cues within cells. They are able to reorganize themselves in response to mechanical forces, converting the stimuli received into specific cellular responses. Thus, the cytoskeleton influences cell shape, proliferation, and even differentiation. In particular, the cytoskeleton affects the fate of mesenchymal stem cells (MSCs), which are highly attractive candidates for cell therapy approaches due to their capacity for self-renewal and multi-lineage differentiation. Cytochalasin B (CB), a cyto-permeable mycotoxin, is able to inhibit the formation of actin microfilaments, resulting in direct effects on cell biological properties. Here, we investigated for the first time the effects of different concentrations of CB (0.1–10 ÎŒM) on human adipose-derived stem cells (hASCs) both after 24 h (h) of CB treatment and 24 h after CB wash-out. CB influenced the metabolism, proliferation, and morphology of hASCs in a dose-dependent manner, in association with progressive disorganization of actin microfilaments. Furthermore, the removal of CB highlighted the ability of cells to restore their cytoskeletal organization. Finally, atomic force microscopy (AFM) revealed that cytoskeletal changes induced by CB modulated the viscoelastic properties of hASCs, influencing their stiffness and viscosity, thereby affecting adipogenic fat

    SATURN: A Technological Demonstration Mission for Distributed SAR Imaging

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    The OHB-Italia S.p.A-led consortium is in the midst of Phase B of SATURN (Synthetic AperTure radar cUbesat foRmation flyiNg), part of ALCOR, an Italian Space Agency (ASI) programme promoting the development of the next generation Italian CubeSats. SATURN is a demonstration mission that features Multiple-Input-Multiple-Output (MIMO) technology applied to a Swarm of CubeSats equipped with Synthetic Aperture Radar (SAR) for Earth Observation. MIMO is based on cooperative active sensors, where each one transmits signals and receives the illuminated common area backscatter related to the entire swarm, increasing measurement performances with a trend approximatively equal to the square of the number of sensors. The complete SATURN constellation features 16 mini-swarms, each of 3 CubeSats, spread over 4 SSOs equally spaced by 3 hours of local time. The constellation is designed to provide an average revisit time of 1.5 h and an interferometric revisit time of 1 day worldwide. The aim of this demonstration mission is to verify MIMO technology applied to SAR on a mini-swarm of 3 CubeSats in close formation on a Low Earth Down-Dusk Sun Synchronous Orbit. Using OHB-I’s M3Multi Mission Modular platform equipped with a miniaturized SAR Instrument, developed by ARESYS S.r.l. and Airbus Italia S.p.A., our mission is able to achieve a resolution of 5x5 m over a 30 km swath. Thus, SATURN enables low-cost, scalable SAR missions for affordable access to space for public and private entities, overcoming the single point of failure of one large and complex satellite. Subsequent swarms, deploying from 3 to 48 CubeSats, are expected to bring technological innovations and improve Italy’s competitiveness in the European and global Earth Observation scenario

    Men and wolves: Anthropogenic causes are an important driver of wolf mortality in human-dominated landscapes in Italy

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    Over the last 40 years the gray wolf (Canis lupus) re-colonized its historical range in Italy increasing human-predator interactions. However, temporal and spatial trends in wolf mortality, including direct and indirect persecution, were never summarized. This study aims to fill this gap by focusing on the situation of Tuscany and Emilia-Romagna regions, hosting a significant proportion of the Italian wolf population, by: (i) identifying the prevalent causes of wolf mortality, (ii) summarizing their temporal and spatial patterns and (iii) applying spatially-explicit Generalized Linear Models to predict wolf persecution. Between October 2005 and February 2021, 212 wolf carcasses were collected and subjected to necropsy, being involved in collisions with vehicles (n = 104), poisoned (n = 45), wounded with gunshot (n = 24) or blunt objects (n = 4) and being hanged (n = 2). The proportion of illegally killed wolves did not increase through time. Most persecution events occurred between October and February. None of our candidate models outperformed a null model and covariates such as the density of sheep farms, number of predations on livestock, or human density were never associated to the probability of having illegally killed wolves, at the municipal scale. Our findings show that conventional correlates of wolf persecution, combined with a supposedly high proportion of non-retrieved carcasses, fail to predict illegal wolf killings in areas where the species have become ubiquitous. The widespread spatial distribution of illegal killings indicates that persecution probably arises from multiple kinds of conflicts with humans, beyond those with husbandry. Wolf conservation in Italy should thus address cryptic wolf killings with multi-disciplinary approaches, such as shared national protocols, socioecological studies, the support of experts’ experience and effective sampling schemes for the detection of carcasses

    Early glycoprotein IIb–IIIa inhibitors in primary angioplasty (EGYPT) cooperation: an individual patient data meta-analysis

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    Background: Even though time-to-treatment has been shown to be a determinant of mortality in primary angioplasty, the potential benefits from early pharmacological reperfusion by glycoprotein (Gp) IIb-IIIa inhibitors are still unclear. The aim of this meta-analysis was to combine individual data from all randomised trials conducted on facilitated primary angioplasty by the use of early Gp IIb-IIIa inhibitors. Methods and results: The literature was scanned by formal searches of electronic databases (MEDLINE, EMBASE) from January 1990 to October 2007. All randomised trials on facilitation by the early administration of Gp IIb-IIIa inhibitors in ST-segment elevation myocardial infarction (STEMI) were examined. No language restrictions were enforced. Individual patient data were obtained from 11 out of 13 trials, including 1662 patients (840 patients (50.5%) randomly assigned to early and 822 patients (49.5%) to late Gp IIb-IIIa inhibitor administration). Preprocedural Thrombolysis in Myocardial Infarction Study (TIMI) grade 3 flow was more frequent with early Gp IIb-IIIa inhibitors. Postprocedural TIMI 3 flow and myocardial blush grade 3 were higher with early Gp IIb IIIa inhibitors but did not reach statistical significance except for abciximab, whereas the rate of complete ST-segment resolution was significantly higher with early Gp IIb-IIIa inhibitors. Mortality was not significantly different between groups, although early abciximab demonstrated improved survival compared with late administration, even after adjustment for clinical and angiographic confounding factors. Conclusions: This meta-analysis shows that pharmacological facilitation with the early administration of Gp IIb IIIa inhibitors in patients undergoing primary angioplasty for STEMI is associated with significant benefits in terms of preprocedural epicardial recanalisation and ST-segment resolution, which translated into non-significant mortality benefits except for abciximab
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