1,344 research outputs found

    Gaze-contingent flicker pupil perimetry detects scotomas in patients with cerebral visual impairments or glaucoma

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    The pupillary light reflex is weaker for stimuli presented inside as compared to outside absolute scotomas. Pupillograph perimetry could thus be an objective measure of impaired visual processing. However, the diagnostic accuracy in detecting scotomas has remained unclear. We quantitatively investigated the accuracy of a novel form of pupil perimetry. The new perimetry method, termed gaze-contingent flicker pupil perimetry, consists of the repetitive on, and off flickering of a bright disk (2 hz; 320 cd/m; 4° diameter) on a gray background (160 cd/m) for 4 seconds per stimulus location. The disk evokes continuous pupil oscillations at the same rate as its flicker frequency, and the oscillatory power of the pupil reflects visual sensitivity. We monocularly presented the disk at a total of 80 locations in the central visual field (max. 15°). The location of the flickering disk moved along with gaze to reduce confounds of eye movements (gaze-contingent paradigm). The test lasted ~5 min per eye and was performed on 7 patients with cerebral visual impairment (CVI), 8 patients with primary open angle glaucoma (age >45), and 14 healthy, age/gender-matched controls. For all patients, pupil oscillation power (FFT based response amplitude to flicker) was significantly weaker when the flickering disk was presented in the impaired as compared to the intact visual field (CVI: 12%, AUC = 0.73; glaucoma: 9%, AUC = 0.63). Differences in power values between impaired and intact visual fields of patients were larger than differences in power values at corresponding locations in the visual fields of the healthy control group (CVI: AUC = 0.95; glaucoma: AUC = 0.87). Pupil sensitivity maps highlighted large field scotomas and indicated the type of visual field defect (VFD) as initially diagnosed with standard automated perimetry (SAP) fairly accurately in CVI patients but less accurately in glaucoma patients. We provide the first quantitative and objective evidence of flicker pupil perimetry's potential in detecting CVI-and glaucoma-induced VFDs. Gaze-contingent flicker pupil perimetry is a useful form of objective perimetry and results suggest it can be used to assess large VFDs with young CVI patients whom are unable to perform SAP

    Validation of the Predictive Model of the European Society of Cardiology for Early Mortality in Acute Pulmonary Embolism

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    Background \u2003Acute pulmonary embolism (PE) is burdened by high mortality, especially within 30 days from the diagnosis. The development and the validation of predictive models for the risk of early mortality allow to differentiate patients who can undergo home treatment from those who need admission into intensive care units. Methods \u2003To validate the prognostic model for early mortality after PE diagnosis proposed by the European Society of Cardiology (ESC) in 2014, we analyzed data of a cohort of 272 consecutive patients with acute PE, observed in our hospital during a 10-year period. Moreover, we evaluated the additional contribution of D-dimer, measured at PE diagnosis, in improving the prognostic ability of the model. All cases of PE were objectively diagnosed by angiography chest CT scan or perfusion lung scan. Results \u2003The overall mortality rate within 30 days from PE diagnosis was 10% (95% confidence interval [CI]: 6.4-13.5%). According to the ESC prognostic model, the risk of death increased 3.23 times in the intermediate-low-risk category, 5.55 times in the intermediate-high-risk category, and 23.78 times in the high-risk category, as compared with the low-risk category. The receiver operating characteristic analysis showed a good discriminatory power of the model (area under the curve [AUC]\u2009=\u20090.77 [95% CI: 0.67-0.87]), which further increased when D-dimer was added (AUC\u2009=\u20090.85 [95% CI: 0.73-0.96]). Conclusion \u2003This study represents a good validation of the ESC predictive model whose performance can be further improved by adding D-dimer plasma levels measured at PE diagnosis

    Un acercamiento al estudio del impacto de una secuencia de enseñanza-aprendizaje para mejorar la definición de tecnología

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    La ponencia se enmarca en el Proyecto Iberoamericano sobre la Naturaleza de la Ciencia y la Tecnología que busca mejorar en estudiantes la comprensión sobre la Naturaleza de la Ciencia y Tecnología (NdCyT), a partir del desarrollo de secuencias de enseñanza-aprendizaje (SEA) como lo es, en este caso, Tecnología: mucho más que aparatos. Ésta pretende hacer evolucionar creencias reduccionistas de estudiantes de nivel medio de Neuquén-Argentina respecto a la definición de Tecnología, involucrándolos en la resolución de una situación problemática como lo es el diseño de un baño en un campamento. Esperando culmine el procesamiento de resultados del pre y post test estandarizado aplicado para valorar el impacto pormenorizado sobre las mismas, adelantamos un somero análisis orientativo de sus respuestas a la actividad de reflexión metacognitiva

    Inverse dynamic modelling of jumping in the red-legged running frog, Kassina maculata

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    Although the red-legged running frog, Kassina maculata, is secondarily a walker/runner, it retains the capacity for multiple locomotor modes, including jumping at a wide range of angles (nearly 70 deg). Using simultaneous hind limb kinematics and single-foot ground reaction forces, we performed inverse dynamics analyses to calculate moment arms and torques about the hind limb joints during jumping at different angles in K. maculata. We show that forward thrust is generated primarily at the hip and ankle, while body elevation is primarily driven by the ankle. Steeper jumps are achieved by increased thrust at the hip and ankle and greater downward rotation of the distal limb segments. Because of its proximity to the GRF vector, knee posture appears to be important in controlling torque directions about this joint and, potentially, torque magnitudes at more distal joints. Other factors correlated with higher jump angles include increased body angle in the preparatory phase, faster joint openings and increased joint excursion, higher ventrally directed force, and greater acceleration and velocity. Finally, we demonstrate that jumping performance in K. maculata does not appear to be compromised by presumed adaptation to walking/running. Our results provide new insights into how frogs engage in a wide range of locomotor behaviours and the multi-functionality of anuran limbs

    Salimicrobium salexigens sp. nov., a moderately halophilic bacterium from salted hides

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    Two Gram-positive, moderately halophilic bacteria, designated strains 29CMIT and 53CMI, were isolated from salted hides. Both strains were non-motile, strictly aerobic cocci, growing in the presence of 3-25 % (w/v) NaCl (optimal growth at 7.5-12.5 % [w/v] NaCl), between pH 5.0 and 10.0 (optimal growth at pH 7.5) and at temperatures between 15 and 40 ºC (optimal growth at 37 ºC). Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that both strains showed a similarity of 98.7 % and were closely related to species of the genus Salimicrobium, within the phylum Firmicutes. Strains 29CMIT and 53CMI exhibited 16S rRNA gene sequence similarity values of 97.9 % to 97.6 % with Salimicrobium album DSM 20748T, Salimicrobium halophilum DSM 4771T, Salimicrobium flavidum ISL-25T and Salimicrobium luteum BY-5T. The DNA G+C content was 50.7 mol% and 51.5 mol% for strains 29CMIT and 53CMI, respectively. The DNA-DNA hybridization between both strains was 98 %, whereas the values between strain 29CMIT and the species Salimicrobium album CCM 3517T, Salimicrobium luteum BY-5T, Salimicrobium flavidum ISL-25T and Salimicrobium halophilum CCM 4074T were 45 %, 28 %,

    A Two-Phase ASP Encoding for Solving Rehabilitation Scheduling

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    The rehabilitation scheduling process consists of planning rehabilitation physiotherapy sessions for patients, by assigning proper operators to them in a certain time slot of a given day, taking into account several requirements and optimizations, e.g., patient’s preferences and operator’s work balancing. Being able to efficiently solve such problem is of upmost importance, in particular after the COVID-19 pandemic that significantly increased rehabilitation’s needs. In this paper, we present a solution to rehabilitation scheduling based on Answer Set Programming (ASP), which proved to be an effective tool for solving practical scheduling problems. Results of experiments performed on both synthetic and real benchmarks, the latter provided by ICS Maugeri, show the effectiveness of our solution

    Transcriptional response to lactic acid stress in the hybrid yeast Zygosaccharomyces parabailii

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    Lactic acid has a wide range of applications starting from its undissociated form, and its production using cell factories requires stress-tolerant microbial hosts. The interspecies hybrid yeast Zygosaccharomyces parabailii has great potential to be exploited as a novel host for lactic acid production, due to high organic acid tolerance at low pH, and a fermentative metabolism with a fast growth rate. Here we used RNA-seq to analyze Z. parabailii's transcriptional response to lactic acid added exogenously, and we explore the biological mechanisms involved in tolerance. Z. parabailii contains two homeologous copies of most genes. Under lactic acid stress, the two genes in each homeolog pair tend to diverge in expression to a significantly greater extent than in control conditions, indicating that stress tolerance is facilitated by interactions between the two gene sets in the hybrid. Lactic acid induces downregulation of genes related to cell wall and plasma membrane functions, possibly altering the rate of diffusion of lactic acid into cells. Genes related to iron transport and redox processes were upregulated, suggesting an important role for respiratory functions and oxidative stress defense. We found differences in the expression profiles of genes putatively regulated by Haa1 and Aft1/2, previously described as lactic acid-responsive in Saccharomyces cerevisiae. Furthermore, formate dehydrogenase (FDH) genes form a lactic acid-responsive gene family that has been specifically amplified in Z. parabailii as compared to other closely related species. Our study provides a useful starting point for the engineering of Z. parabailii as a host for lactic acid production.Importance Hybrid yeasts are important in biotechnology because of their tolerance to harsh industrial conditions. The molecular mechanisms of tolerance can be studied by analyzing differential gene expression in conditions of interest, and relating gene expression patterns to protein functions. However, hybrid organisms present a challenge to the standard use of mRNA sequencing (RNA-seq) to study transcriptional responses to stress, because their genomes contain two similar copies of almost every gene. Here we used stringent mapping methods and a high-quality genome sequence to study the transcriptional response to lactic acid stress in Zygosaccharomyces parabailii ATCC60483, a natural interspecies hybrid yeast that contains two complete subgenomes that are approximately 7% divergent in sequence. Beyond the insights we gained into lactic acid tolerance in this study, the methods we developed will be broadly applicable to other yeast hybrid strains

    First step in the nuclear inverse Kohn-Sham problem: From densities to potentials

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    Nuclear density functional theory (DFT) plays a prominent role in the understanding of nuclear structure, being the approach with the widest range of applications. Hohenberg and Kohn theorems warrant the existence of a nuclear energy density functional (EDF), yet its form is unknown. Current efforts to build a nuclear EDF are hindered by the lack of a strategy for systematic improvement. In this context, alternative approaches should be pursued and, so far, an unexplored avenue is that related to the inverse DFT problem. DFT is based on the one-to-one correspondence between Kohn-Sham (KS) potentials and densities. The exact EDF produces the exact density, so that from the knowledge of experimental or ab initio densities one may deduce useful information through reverse engineering. The idea has already been proved to be useful in the case of electronic systems. The general problem should be dealt with in steps, and the objective of the present work is to focus on testing algorithms to extract the Kohn-Sham potential within the simplest ansatz from the knowledge of the experimental neutron and proton densities. We conclude that, while robust algorithms exist, the experimental densities present some critical aspects. Finally, we provide some perspectives for future works

    Endothelial Dysfunction in Patients with Severe Mitral Regurgitation

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    Mitral valve prolapse (MVP) is the most common cause of severe mitral regurgitation. It has been reported that MVP patients-candidates for mitral valve repair (MVRep)-showed an alteration in the antioxidant defense systems as well as in the L-arginine metabolic pathway. In this study, we investigate if oxidative stress and endothelial dysfunction are an MVP consequence or driving factors. Forty-five patients undergoing MVRep were evaluated before and 6 months post surgery and compared to 29 controls. Oxidized (GSSG) and reduced (GSH) forms of glutathione, and L-arginine metabolic pathway were analyzed using liquid chromatography-tandem mass spectrometry methods while osteoprotegerin (OPG) through the ELISA kit and circulating endothelial microparticles (EMP) by flow cytometry. Six-month post surgery, in MVP patients, the GSSG/GSH ratio decreased while symmetric and asymmetric dimethylarginines levels remained comparable to the baseline. Conversely, OPG levels significantly increased when compared to their baseline. Finally, pre-MVRep EMP levels were significantly higher in patients than in controls and did not change post surgery. Overall, these results highlight that MVRep completely restores the increased oxidative stress levels, as evidenced in MVP patients. Conversely, no amelioration of endothelial dysfunction was evidenced after surgery. Thus, therapies aimed to restore a proper endothelial function before and after surgical repair could benefit MVP patients

    Serum protein profiling of early and advanced stage Crohn's disease

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    AbstractCrohn's disease (CD) represents a highly debilitating disease of difficult diagnosis and increasing incidence. Serum protein profiling of early stage Crohn's disease (ES) CD was investigated in order to improve the comprehension of the very early pathologic mechanisms and to support the difficult diagnostic procedures currently available. Inflammatory proteins and complement 3 chain C (C3c) were over-represented during ES CD, clusterin, retinol binding protein, α1-microglobulin and transthyretin were under-represented. A C3c isoform was found to be present only during ES CD. By now, lack of specific antibodies to detect isoforms made it impossible to perform alternative validation
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