447 research outputs found

    Coupling stem water potential and soil water potential on irrigated and not irrigated vines: preliminary results for Vitis vinifera L. cv Teroldego

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    Improving wine quality necessitates precise control over plant water stress, which requires accurate scheduling of irrigation based on the plant's water status and the soil's water availability. The aim of this experiment is to monitor the water status of grapevines and soil in both irrigated and not-irrigated conditions to quantify differences in the plant's physiological response and yield. In addition, novel microtensiometer probes for measuring continuously the Stem Water Potential were tested for efficacy. These probes were coupled with a handcrafted tensiometer to monitor the Soil Water status and at the end of the season all the yield was analyzed to determine the main oenological parameters driving the final quality of the musts. Initial findings indicate that the microtensiometers gave effective estimates of the vines’ water status, revealing rapid plant responses to water inputs and atmospheric changes. Notably for the experiment, soil moisture exceeded field capacity under irrigated vines before irrigation, suggesting potential water loss through deep percolation, and both the irrigated and not-irrigated vines were in water comfort for all the vegetative season without any detriment both in production and quality

    Development of the visual white matter pathways mediates development of electrophysiological responses in visual cortex

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    The latency of neural responses in the visual cortex changes systematically across the lifespan. Here, we test the hypothesis that development of visual white matter pathways mediates maturational changes in the latency of visual signals. Thirty-eight children participated in a cross-sectional study including diffusion magnetic resonance imaging (MRI) and magnetoencephalography (MEG) sessions. During the MEG acquisition, participants performed a lexical decision and a fixation task on words presented at varying levels of contrast and noise. For all stimuli and tasks, early evoked fields were observed around 100 ms after stimulus onset (M100), with slower and lower amplitude responses for low as compared to high contrast stimuli. The optic radiations and optic tracts were identified in each individual's brain based on diffusion MRI tractography. The diffusion properties of the optic radiations predicted M100 responses, especially for high contrast stimuli. Higher optic radiation fractional anisotropy (FA) values were associated with faster and larger M100 responses. Over this developmental window, the M100 responses to high contrast stimuli became faster with age and the optic radiation FA mediated this effect. These findings suggest that the maturation of the optic radiations over childhood accounts for individual variations observed in the developmental trajectory of visual cortex responses

    Alginate Formulations: Current Developments in the Race for Hydrogel-Based Cardiac Regeneration

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    Cardiovascular diseases, including myocardial infarction (MI), represent the main worldwide cause of mortality and morbidity. In this scenario, to contrast the irreversible damages following MI, cardiac regeneration has emerged as a novel and promising solution for in situ cellular regeneration, preserving cell behavior and tissue cytoarchitecture. Among the huge variety of natural, synthetic, and hybrid compounds used for tissue regeneration, alginate emerged as a good candidate for cellular preservation and delivery, becoming one of the first biomaterial tested in pre-clinical research and clinical trials concerning cardiovascular diseases. Although promising results have been obtained, recellularization and revascularization of the infarcted area present still major limitations. Therefore, the demand is rising for alginate functionalization and its combination with molecules, factors, and drugs capable to boost the regenerative potential of the cardiac tissue. The focus of this review is to elucidate the promising properties of alginate and to highlight its benefits in clinical trials in relation to cardiac regeneration. The definition of hydrogels, the alginate characteristics, and recent biomedical applications are herewith described. Afterward, the review examines in depth the ongoing developments to refine the material relevance in cardiac recovery and regeneration after MI and presents current clinical trials based on alginate

    Increased Functional Connectivity in the Default Mode Network in Mild Cognitive Impairment: A Maladaptive Compensatory Mechanism Associated with Poor Semantic Memory Performance

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    Semantic memory decline and changes of default mode network (DMN) connectivity have been reported in mild cognitive impairment (MCI). Only a few studies, however, have investigated the role of changes of activity in the DMN on semantic memory in this clinical condition. The present study aimed to investigate more extensively the relationship between semantic memory impairment and DMN intrinsic connectivity in MCI. Twenty-one MCI patients and 21 healthy elderly controls matched for demographic variables took part in this study. All participants underwent a comprehensive semantic battery including tasks of category fluency, visual naming and naming from definition for objects, actions and famous people, word-association for early and late acquired words and reading. A subgroup of the original sample (16 MCI patients and 20 healthy elderly controls) was also scanned with resting state functional magnetic resonance imaging and DMN connectivity was estimated using a seed-based approach. Compared with healthy elderly, patients showed an extensive semantic memory decline in category fluency, visual naming, naming from definition, words-association, and reading tasks. Patients presented increased DMN connectivity between the medial prefrontal regions and the posterior cingulate and between the posterior cingulate and the parahippocampus and anterior hippocampus. MCI patients also showed a significant negative correlation of medial prefrontal gyrus connectivity with parahippocampus and posterior hippocampus and visual naming performance. Our findings suggest that increasing DMN connectivity may contribute to semantic memory deficits in MCI, specifically in visual naming. Increased DMN connectivity with posterior cingulate and medio-temporal regions seems to represent a maladaptive reorganization of brain functions in MCI, which detrimentally contributes to cognitive impairment in this clinical population

    Associations between neuropsychiatric symptoms and Alzheimer’s disease biomarkers in people with mild cognitive impairment

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    Background: Neuropsychiatric symptoms (NPS) are associated with faster decline in mild cognitive impairment (MCI). This study aimed to investigate the association between NPS severity and Alzheimer’s disease (AD) biomarkers, i.e., amyloid-β (Aβ), phosphorylated tau protein (p-tau) and hippocampal volume ratio (HR), to characterise in more detail MCI patients with a poor prognosis. Methods: A total of 506 individuals with MCI and 99 cognitively unimpaired older adults were selected from the ADNI dataset. The patients were divided into three different groups based on their NPI-Q total scores: no NPS (n = 198), mild NPS (n = 160) and severe NPS (n = 148). Regression models were used to assess the association between the severity of NPS and each biomarker level and positivity status. Results: Cerebrospinal fluid Aβ levels were positively associated with older age and lower MMSE scores, while higher p-tau levels were associated with female sex and lower MMSE scores. Only patients with severe NPS had a lower HR (β = −0.18, p = 0.050), i.e., more pronounced medio-temporal atrophy, than those without NPS. Discussion: Only HR was associated with the presence of NPS, partially in line with previous evidence showing that severe NPS may be explained primarily by greater grey matter loss. Future longitudinal studies will be needed to ascertain the relevance of this finding
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