832 research outputs found

    Complex Symplectic Lie Algebras with Large Abelian Subalgebras

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    We present two constructions of complex symplectic structures on Lie algebras with large abelian ideals. In particular, we completely classify complex symplectic structures on almost abelian Lie algebras. By considering compact quotients of their corresponding connected, simply connected Lie groups we obtain many examples of complex symplectic manifolds which do not carry (hyper)k\"ahler metrics. We also produce examples of compact complex symplectic manifolds endowed with a fibration whose fibers are Lagrangian tori.Comment: 33 pages, no figures. Comments are welcome

    Abnormal salivary total and oligomeric alpha-synuclein in Parkinson's disease

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    In Parkinson’s disease (PD), alpha-synuclein (a-syn) can be detected in biological fluids including saliva. Although previous studies found reduced a-syn total (a-syntotal) concentration in saliva of PD patients, no studies have previously examined salivary a-syn oligomers (a-synolig) concentrations or assessed the correlation between salivary a-syntotal, a-synolig and clinical features in a large cohort of PD patients. Is well known that a-synolig exerts a crucial neurotoxic effect in PD. We collected salivary samples from 60 PD patients and 40 age- and sex-comparable healthy subjects. PD was diagnosed according to the United Kingdom Brain Bank Criteria. Samples of saliva were analyzed by specific anti-a-syn and anti-oligomeric a-syn ELISA kits. A complete clinical evaluation of each patient was performed using MDS-Unified Parkinson's Disease Rating Scale, Beck Depression Inventory, Montreal Cognitive Assessment and Frontal Assessment Battery. Salivary a-syntotal was lower, whereas a-synolig was higher in PD patients than healthy subjects. The a-synolig/a-syntotal ratio was also higher in patients than in healthy subjects. Salivary a-syntotal concentration negatively correlated with that of a-synolig and correlated with several patients’ clinical features. In PD, decreased salivary concentration of a-syntotal may reflect the reduction of a-syn monomers (a-synmon), as well as the formation of insoluble intracellular inclusions and soluble oligomers. The combined detection of a-syntotal and a-synolig in the saliva might help the early diagnosis of P

    Hacia una actualizaciĂłn y apropiaciĂłn del horizonte institucional del colegio Mayor de Occidente de FacatativĂĄ

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    80 PĂĄginas.En este trabajo se analiza el Horizonte Institucional existente del Colegio Mayor de Occidente y por medio de una serie de encuestas aplicadas a todos los grupos de la comunidad educativa se evalĂșa dicho Horizonte, luego se presenta una propuesta de mejora teniendo en cuenta los aportes obtenidos por la comunidad, la nueva propuesta debe ser socializada antes de ser aprobada por el consejo directivo, una vez aprobada, se da a conocer el nuevo Horizonte Institucional a todos los miembros de la comunidad para que de ahĂ­ en adelante se trabaje en la apropiaciĂłn del mismo

    Validation of a guideline to reduce variability in diagnosing cervical dystonia

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    Background: Cervical dystonia is characterized by a variable pattern of neck muscle involvement. Due to the lack of a diagnostic test, cervical dystonia diagnosis is based on clinical examination and is therefore subjective. The present work was designed to provide practical guidance for clinicians in confirming or refuting suspected cervical dystonia. Methods: Participants were video recorded according to a standardized protocol to assess 6 main clinical features possibly contributing to cervical dystonia diagnosis: presence of repetitive, patterned head/neck movements/postures inducing head/neck deviation from neutral position (item 1); sensory trick (item 2); and red flags related to conditions mimicking dystonia that should be absent in dystonia (items 3-6). Inter-/intra-rater agreement among three independent raters was assessed by k statistics. To estimate sensitivity and specificity, the gold standard was cervical dystonia diagnosis reviewed at each site by independent senior neurologists. Results: The validation sample included 43 idiopathic cervical dystonia patients and 41 control subjects (12 normal subjects, 6 patients with isolated head tremor, 4 with chorea, 6 with tics, 4 with head ptosis due to myasthenia or amyotrophic lateral sclerosis, 7 with orthopedic/rheumatologic neck diseases, and 2 with ocular torticollis). The best combination of sensitivity and specificity was observed considering all the items except for an item related to capability to voluntarily suppress spasms (sensitivity: 96.1%; specificity: 81%). Conclusions: An accurate diagnosis of cervical dystonia can be achieved if, in addition to the core motor features, we also consider some clinical features related to dystonia mimics that should be absent in dystonia

    Expression and regulation of α-transducin in the pig gastrointestinal tract

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    Taste signalling molecules are found in the gastrointestinal (GI) tract suggesting that they participate to chemosensing. We tested whether fasting and refeeding affect the expression of the taste signalling molecule, a-transducin (Gatran), throughout the pig GI tract and the peptide content of Gatran cells. The highest density of Gatran-immunoreactive (IR) cells was in the pylorus, followed by the cardiac mucosa, duodenum, rectum, descending colon, jejunum, caecum, ascending colon and ileum. Most Gatran-IR cells contained chromogranin A. In the stomach, many Gatran-IR cells contained ghrelin, whereas in the upper small intestine many were gastrin/cholecystokinin-IR and a few somatostatin-IR. Gatran-IR and Gagust-IR colocalized in some cells. Fasting (24 h) resulted in a significant decrease in Gatran-IR cells in the cardiac mucosa (29.3 0.8 versus 64.8 1.3, P < 0.05), pylorus (98.8 1.7 versus 190.8 1.9, P < 0.0 l), caecum (8 0.01 versus 15.5 0.5, P < 0.01), descending colon (17.8 0.3 versus 23 0.6, P < 0.05) and rectum (15.3 0.3 versus 27.5 0.7, P < 0.05). Refeeding restored the control level of Gatran-IR cells in the cardiac mucosa. In contrast, in the duodenum and jejunum, Gatran-IR cells were significantly reduced after refeeding, whereas Gatran-IR cells density in the ileum was not changed by fasting/refeeding. These findings provide further support to the concept that taste receptors contribute to luminal chemosensing in the GI tract and suggest they are involved in modulation of food intake and GI function induced by feeding and fasting

    Corneal endothelium assessment in specular microscopy images with Fuchs’ dystrophy via deep regression of signed distance maps

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    Specular microscopy assessment of the human corneal endothelium (CE) in Fuchs’ dystrophy is challenging due to the presence of dark image regions called guttae. This paper proposes a UNet-based segmentation approach that requires minimal post-processing and achieves reliable CE morphometric assessment and guttae identification across all degrees of Fuchs’ dystrophy. We cast the segmentation problem as a regression task of the cell and gutta signed distance maps instead of a pixel-level classification task as typically done with UNets. Compared to the conventional UNet classification approach, the distance-map regression approach converges faster in clinically relevant parameters. It also produces morphometric parameters that agree with the manually-segmented ground-truth data, namely the average cell density difference of -41.9 cells/mm2 (95% confidence interval (CI) [-306.2, 222.5]) and the average difference of mean cell area of 14.8 ”m 2 (95% CI [-41.9, 71.5]). These results suggest a promising alternative for CE assessment.This work has been partly funded by Ministerio de Ciencia, TecnologĂ­a e InnovaciĂłn, Colombia, Project 124489786239 (Contract 763-2021), Universidad TecnolĂłgica de BolĂ­var (UTB) Project CI2021P02, and Agencia Estatal de InvestigaciĂłn del Gobierno de España (PID2020-114582RB-I00/ AEI / 10.13039/501100011033). J. Sierra thanks UTB for a post-graduate scholarship.Peer ReviewedPostprint (published version

    Caregiver burden and its related factors in advanced Parkinson’s disease: data from the PREDICT study

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    Introduction: Caring for a person with Parkinson’s disease (PD) is associated with an increased risk of psychiatric morbidity and persistent distress. The objective of this study was to describe the burden and the related factors of caregivers of advanced PD (APD) patients either treated with continuous dopaminergic delivery systems or standard therapy. Methods: This cross-sectional, epidemiologic study conducted in 13 Italian sites enrolled PD patients treated with continuous dopaminergic delivering systems [either levodopa/carbidopa intestinal gel (LCIG) infusion or continuous subcutaneous apomorphine infusion (CSAI)] or continuation of standard of care (SOC) with a caregiver. Patient quality of life (QoL) and caregiver burden were assessed using the Parkinson’s Disease Questionnaire (PDQ-8) and Zarit Burden Inventory (ZBI), respectively. Results: 126 patients (mean age 69.3 ± 8 years) and their caregivers (mean age 57.9 ± 12.9) were enrolled. Most caregivers were spouses. Fifty-three patients were treated with LCIG, 19 with CSAI, and 54 with SOC. Mean ZBI scores were 29.6 ± 14.4 for LCIG, 35.8 ± 20.2 for CSAI, and 31.4 ± 16.0 for SOC. Caregivers of LCIG, CSAI, and SOC patients showed no burden or mild/moderate burden in 74, 53, and 63% of the cases, respectively. Mean PDQ-8 scores were 11.25 ± 5.67, 11.26 ± 5.55, and 14.22 ± 6.51 in LCIG, CSAI, and SOC patients. Neurologists considered patients “very much or much improved” in 89, 58, and 13% of the LCIG, CSAI, and SOC groups using the Clinical Global Impression–Global Improvement Scale. Predictors significantly associated with caregiver burden were patients and caregivers’ judgment of QoL and caregivers’ need to change work. Conclusions: Caregiver burden showed a tendency to be lower when patients are treated with LCIG than with CSAI or SOC

    Application and uses of electronic noses for clinical diagnosis on urine samples: A review

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    The electronic nose is able to provide useful information through the analysis of the volatile organic compounds in body fluids, such as exhaled breath, urine and blood. This paper focuses on the review of electronic nose studies and applications in the specific field of medical diagnostics based on the analysis of the gaseous headspace of human urine, in order to provide a broad overview of the state of the art and thus enhance future developments in this field. The research in this field is rather recent and still in progress, and there are several aspects that need to be investigated more into depth, not only to develop and improve specific electronic noses for different diseases, but also with the aim to discover and analyse the connections between specific diseases and the body fluids odour. Further research is needed to improve the results obtained up to now; the development of new sensors and data processing methods should lead to greater diagnostic accuracy thus making the electronic nose an effective tool for early detection of different kinds of diseases, ranging from infections to tumours or exposure to toxic agents
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