1,158 research outputs found

    Cortical synchrony across cognitive processing stages:dynamics & coordinating mechanisms

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    Any cognitive task requires of executing a set of elementary cognitive processes. These cognitive process are assumed to require of coordinating specific regions of the brain. However, the patterns of neural coordination related to each cognitive process were never measured due to some technical limitations. In this thesis we overcame these limitations and measured the patterns of neural coordination at each elementary processing stage in a memory task. Indeed, our results show that a new pattern of neural coordination emerges at the onset of each processing stage. Furthermore, we investigated the mechanisms that cause these switches between patterns of neural coordination. To this end, we developed the first whole-brain model that can simulate large-scale neural coordination throughout a cognitive task. First we showed that this model is able to simulate the dynamics of neural coordination during resting state. Next we showed that short pulses of neural activity targeted at specific brain regions cause the switching between states of neural coordination associated with elementary cognitive processes

    Impact in the reduction of complications through a personalized follow-up strategy to ensure adherence to antihypertensive therapy

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    The lack in continuity of antihypertensive treatment is one of the major common causes of uncontrolled high blood pressure and increased of adverse effects and medical costs associated to this disease. The current study aimed to investigate the relationship between a personalized strategy that guarantees the adherence to antihypertensive treatment and complications related to hypertension. To do so, 586 patients hypertensive patients attending primary care institutions in La Plata Argentina, were randomly assigned either to an intervention group that had regular and periodically follow up contact to check treatment adherence or to control group. Both groups received free of charge antihypertensive medicines. The adherence was assessed with the adherence evaluation scale of Girerd. The presence of complications of hypertension disease (stroke, angina pectoris, myocardial infarct, transient ischemic attack, heart failure, kidney failure, retinopathy and death associated to this disease) were checked monthly. Among the 293 patients included in the intervention group study 98.63 % (289/293) were adherents while only 49.14% (144/293) of the control group had continuity in the therapy. Comparing complications events developed by patients belonging to Intervention vs Control group after 24 month of follow up were for overall events 19.79% vs 27.98% (p<0.001), for stoke 0.34/1.02%(pNS); angina pectoris 4.09/6.48% (p 0.004), 0.68/1.02 (pNS), TIA 0/0.34% (p NS), heart failure 4.77 /7.16% (p0.003), while hospitalization associate to primary hypertension disease was 16.04/30.3% (p<0.001)respectively. We can conclude that a personalized strategy to guarantee hypertension treatment adherence reduce the hospitalization and several complication associated to this disease.Fil: Marin, Gustavo Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: Marin, Lupe. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; ArgentinaFil: Errecalde, Jorge Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Médicas; Argentin

    Universality of Tip Singularity Formation in Freezing Water Drops

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    A drop of water deposited on a cold plate freezes into an ice drop with a pointy tip. While this phenomenon clearly finds its origin in the expansion of water upon freezing, a quantitative description of the tip singularity has remained elusive. Here we demonstrate how the geometry of the freezing front, determined by heat transfer considerations, is crucial for the tip formation. We perform systematic measurements of the angles of the conical tip, and reveal the dynamics of the solidification front in a Hele-Shaw geometry. It is found that the cone angle is independent of substrate temperature and wetting angle, suggesting a universal, self-similar mechanism that does not depend on the rate of solidification. We propose a model for the freezing front and derive resulting tip angles analytically, in good agreement with observations.Comment: Letter format, 5 pages, 3 figures. Note: authors AGM and ORE contributed equally to the pape

    A global synthesis of the impacts of urbanization on bird dawn choruses

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    Urbanization drives changes in acoustic communication systems in some animal species. Noise and light pollution are among the main urban factors known to disrupt the timing and structure of avian singing behaviour. Despite our understanding of the ways in which urbanization can drive variations in avian acoustic communication, our ability to generalize the underlying causes of such variation and its consequences is still limited. Here, we reviewed the literature focused on the study of avian dawn choruses in urban settings at a global scale. Our findings reveal that avian dawn chorus research has focused on the impact of anthropogenic noise on dawn chorus traits (i.e. timing, peak, song output, song frequencies); relationships between light pollution and chorus timing; the effects of temperature, cloudiness, moonlight and natural light on chorus timing; relationships between nocturnal noise and light, and dawn chorus timing; the effects of chemical pollution and supplementary feeding on dawn chorus activity; and ecological patterns of dawn choruses in soundscapes across urban-non-urban gradients. We identified important knowledge gaps in the study of avian dawn choruses in urban settings and thus suggest future research directions, including frameworks (e.g. the urbanization intensity gradient) and consideration of a wider array of urban conditions and variables. Given the complexity of urban settings, we encourage further studies to address the role that all sources of pollution can have on avian acoustic communication at dawn. Additionally, a central question to resolve is whether the function of avian dawn choruses in urban areas differs, and if so how, from non-urban counterparts. Given that most research has been performed across Holarctic cities and towns, studies from tropical and subtropical regions are needed if we aim to understand the phenomenon globally. Finally, studies at the community- and soundscape-level across cities could advance understanding of the way in which urban birds use the acoustic space during the most critical singing time period, dawn.Peer reviewe

    Erythropoietin treatment in chronic renal failure anaemia-biosimilar option in the rational use of medicine process in order to reduced public health economic burden

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    Biopharmaceuticals innovation molecules have changed the course of a large number of chronic diseases. Many of these molecules became Gold Standards in oncology, rheumatology and other illness. However, their cost makes these drugs unattainable for most patients, and often put the health systems’ budgets at risk. This study takes the anaemia due to Chronic Renal Failure disease (CRFD) as an example to a rational selection of treatment with erythropoietin (EPO) and compares the trade brand mark of this drug with biosimilars option. Prescriptions of EPO in 394 patients with CRFD were submitted to a protocol of rational selection based in efficacy/risk ratio demonstration. This protocol was able to reduce that initial number to 91 cases that could really benefited with EPO treatment. These patients were included in a cohort study that compared EPO trade mark with biosimilars option. The experience demonstrated equal clinical outcomes in both groups but a reduction to half the original cost when biosimilars were dispensed. Biosimilars demonstrated to be a cheap and safe option to increase medicine access for anaemia associated to CRFD.Fil: Marin, Gustavo Horacio. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Articulación de Ciencias Básicas y Clínicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Marin, Lupe. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Articulación de Ciencias Básicas y Clínicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Haag, Griselda Octavia. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Articulación de Ciencias Básicas y Clínicas; ArgentinaFil: Risso, Paula. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Articulación de Ciencias Básicas y Clínicas; ArgentinaFil: Errecalde, Jorge Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Articulación de Ciencias Básicas y Clínicas; Argentin

    The interplay of product modularity, service types, and servitization depth on firm performance:a moderated mediation model

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    The servitization literature has explored the role that product modularity plays in supporting service design and delivery. Importantly, product modularity has the potential to aid manufacturers in providing customized solutions on a larger scale, thereby strengthening firm performance. However, despite the prospective benefits of product modularity, manufacturers also need considerable servitization depth, which comprises service orientation, resources, and delivery systems, to provide services in a cost-effective manner. Taking this into account, the study both theoretically articulates and empirically tests relationships among product modularity, servitization depth, service types, and firm performance, employing a moderated mediation model. Using survey data collected from 204 manufacturers in the UK and German, the findings indicate that product modularity exerts a positive influence on firm performance, with servitization depth acting as a mediating factor. The mediation effect of servitization depth on the correlation between product modularity and firm performance was found to fluctuate based on the service types offered by the manufacturer. This study adds to the existing literature on servitization and the role of product modularity and servitization depth in achieving superior firm performance

    The Involvement of Urinary Kallikrein in the Renal Escape from the Sodium Retaining Effect of Mineralocorticoids

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    It is well known that the normal kidney escapes the sodium retaining effect of mineralocorticoids. However, the mechanism that mediates this escape is not understood. The possible role of kallikrein in this escape phenomenon was investigated by placing seven dogs in metabolic cages and giving them a constant sodium diet. After they had been on this diet three days, urine was collected for two 24-hour periods. DOCA (25 mg/day) was then given intramuscularly for five days. Urine was collected daily during this DOCA period and for two additional 24- hour periods. Urine volume, sodium, potassium, protein, and kallikrein excretion were then measured. Urinary kallikrein increased from 251.9 ± 34.8 (mean ± SE) in the second day of the control period to 639.8 ± 110.1 IJ-g/day (P \u3c .01) by the third day of treatment. It remained elevated two days after DOCA was discontinued. Sodium excretion decreased significantly on the first day of DOCA treatment, returning to the previous values thereafter. Urine protein excretion remained constant. The enhanced urinary kallikrein during the escape suggests that the kallikrein system could be involved in the regulation of sodium metabolism by acting as a natriuretic factor, or perhaps by regulating the renal blood flow

    Partial Phase Cohesiveness in Networks of Networks of Kuramoto Oscillators

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    Partial, instead of complete, synchronization has been widely observed in various networks including, in particular, brain networks. Motivated by data from human brain functional networks, in this technical note, we analytically show that partial synchronization can be induced by strong regional connections in coupled subnetworks of Kuramoto oscillators. To quantify the required strength of regional connections, we first obtain a critical value for the algebraic connectivity of the corresponding subnetwork using the incremental 2-norm. We then introduce the concept of the generalized complement graph, and obtain another condition on the node strength by using the incremental infinity-norm. Under these two conditions, regions of attraction for partial phase cohesiveness are estimated in the forms of the incremental 2- and infinity-norms, respectively. Our result based on the incremental infinity-norm is the first known criterion that applies to non-complete graphs. Numerical simulations are performed on a two-level network to illustrate our theoretical results; more importantly, we use real anatomical brain network data to show how our results may contribute to a better understanding of the interplay between anatomical structure and empirical patterns of synchrony
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