248 research outputs found

    Optimal navigability of weighted human brain connectomes in physical space

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    The architecture of the human connectome supports efficient communication protocols relying either on distances between brain regions or on the intensities of connections. However, none of these protocols combines information about the two or reaches full efficiency. Here, we introduce a continuous spectrum of decentralized routing strategies that combine link weights and the spatial embedding of connectomes to transmit signals. We applied the protocols to individual connectomes in two cohorts, and to cohort archetypes designed to capture weighted connectivity properties. We found that there is an intermediate region, a sweet spot, in which navigation achieves maximum communication efficiency at low transmission cost. Interestingly, this phenomenon is robust and independent of the particular configuration of weights.Our results indicate that the intensity and topology of neural connections and brain geometry interplay to boost communicability, fundamental to support effective responses to external and internal stimuli and the diversity of brain functions.Comment: 49 pages (10 main text, 39 Supplementary Material

    Decomposing differences in total factor productivity across firm size

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    This paper investigates the extent to which the gap in total factor productivity between small and large firms is due to differences in the endowment of factors determining productivity and to the returns associated with these factors. We place particular emphasis on the contribution of differences in the propensity to innovate and in the use of skilled labor across firms of different size. Empirical evidence from a representative sample of Spanish manufacturing firms corroborates that both differences in endowments and returns to innovation and skilled labor significantly contribute to the productivity gap between small and large firms. In addition, it is observed that the contribution of innovation to this gap is caused only by differences in quantity, while differences in returns have no effect; in the case of human capital, however, most of the effect can be attributed to increasing differences in returns between small and large firms

    Do innovation and human capital explain the productivity gap between small and large firms?

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    Empirical evidence is compelling that large firms are more productive than small firms. The hypothesis in this paper is that the productivity differences between small and large firms are associated with two of the main determinants of a firm’s performance: the human and technological capital that firms incorporate. We suggest that the contribution of these factors in explaining the productivity-size gap might not only be due to the fact that large firms make a more extensive use of them, but also because large firms obtain higher returns from their investment in human and technological capital. The evidence we obtain for a comprehensive sample of Spanish manufacturing firms (1990-2002) supports this hypothesis, which has important implications for the effectiveness of policies designed to improve productivity in SMEs by stimulating innovation and the use of more skilled workers

    Valoració per carpetes de les estades clíniques dels estudis de fisioteràpia de l'EUCS Manresa

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    L'objectiu general que ens proposem aconseguir al llarg d'aquesta assignatura, és integrar el procés d'avaluació dins del procés d'ensenyament-aprenentatge, i aconseguir que els mateixos estudiants esdevinguin més autònoms a l'hora de controlar el seu procés d'aprenentatge

    Peroxisome Proliferator-Activated Receptor β/δ (PPAR β/δ) as a Potential Therapeutic Target for Dyslipidemia

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    Dyslipidemia is a powerful predictor of cardiovascular disease in patients at high risk (Turner et al., 1998), such as type 2 diabetic patients. Lowering of LDL-C is the prime target for treatment (2002), but even with intensification of statin therapy, a substantial residual cardiovascular risk remains (Barter et al., 2007; Miller et al., 2008; Fruchart et al., 2008; Shepherd et al., 2006). This may partly be due to atherogenic dyslipidemia. This term is commonly used to describe a condition of abnormally elevated plasma triglycerides and low high-density lipoprotein cholesterol (HDL-C), irrespective of the levels of LDL-C (Grundy, 1995). In addition to these key components, increased levels of small, dense LDL-C particles are also present, which in conjunction with the former components conform the also called “lipid triad” (Shepherd et al., 2005). Other abnormalities include accumulation in plasma of triglyceride-rich lipoproteins (TLRs), including chylomicron and very-low-density lipoprotein (VLDL) remnants. This is reflected by elevated plasma concentrations of non- HDL-C and apolipoprotein B-100 (apoB). Postprandially, there is also accumulation in plasma of TLRs and their remnants, as well as qualitative alterations in LDL and HDL particles. Thus, hypertriglyceridemia is associated with a wide spectrum of atherogenic lipoproteins not measured routinely (Taskinen, 2003). The presence of this lipid plasma profile with high triglyceride and low HDL-C levels have been shown to increase the risk of cardiovascular events independent of conventional risk factors (Bansal et al., 2007; Barter et al., 2007; deGoma et al., 2008). In fact, guidelines recommend modifying high triglyceride and low HDL-C as secondary therapeutic targets to provide additional vascular protection (2002). The presence of atherogenic dyslipidemia is seen in almost all patients with triglycerides > 2.2 mmol/l and HDL-C < 1.0 mmol/l, virtually all of whom have type 2 diabetes or abdominal obesity and insulin resistance (Taskinen, 2003)..

    Single layer mortars with microencapsulated PCM: Study of physical and thermal properties, and fire behaviour

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    Phase change materials are a promising strategy to reduce energy consumption in a wide range of applications including the building sector. Many studies have been done to evaluate the impact of PCM on thermal properties of building materials, however there exists little information on the influence of PCM on other properties of the support materials. This knowledge is necessary to determine the feasibility to apply and use building materials containing PCM. In this paper, the effect of the addition of different percentages of microencapsulated phase change material on the properties of two commercial single layer mortars has been studied. Physical and thermal properties as well as fire reaction have been evaluated

    Addition of microencapsulated PCM into single layer mortar: physical and thermal properties and fire resistance

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    The energy consumption in buildings has increased in the last years due to the energy demand for thermal comfort. The improvement of thermal properties in building materials is one of the key points to achieve a reduction of the energy demand. Thermal energy storage (TES) is an alternative to save energy that has been investigated extensively in recent years. The addition of phase change materials (PCM) in a material increases its thermal inertia because PCM are able to store and release energy in sensible and latent heat. In this paper coatings used in the outer walls of buildings are studied, in particular single layer mortar. Microencapsulated paraffin PCM is added into the material to improve the thermal properties of the building envelope. The use of PCM combined with thermal insulation can reduce the energy consumption of buildings by absorbing heat gains and reducing the heat flow. Two types of single layer mortar Weber.Therm.Mineral commerzialized by Weber Saint Gobain incorporating different percentages of microencapsulated PCM type Micronal® DS5001 (20%, 10% and 0%) in their formulations are studied in this paper. The main objective of this work is to analyze the effect of PCM addition on the properties of two single layer mortars. Fresh mortar properties, as well as fire behavior, physical, mechanical and thermal properties of hardened mortar have been evaluated. The results show that physical and mechanical properties of single layer mortar are affected by the addition of microencapsulated PCM. Compressive strength decreases 60% with the addition of 20% of PCM in the formulation while the formulation with 10% of PCM has approximately the same compressive strength than a single layer mortar without PCM. The addition of PCM in the formulation decreases in 35% the adherence of the single layer mortar to a concrete surface. The presence of PCM in the mortar formulation worsens the fire behavior, due to the organic, and therefore flammable, composition of Micronal® DS5001. Flammability increases according to the percentage of PCM added. As a general conclusion, physical and mechanical properties of the single layer mortar become worse when the percentage of the added microencapsulated PCM is increased. Nevertheless, an improvement of thermal properties is expected and the quantification will be done that could justify the addition of PCM to some extent.Peer ReviewedPostprint (published version

    Worldwide use of HPV self-sampling for cervical cancer screening

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    An increasing body of evidence supports the validity of self-sampling as an alternative to clinician collection for primary Human Papillomavirus (HPV) screening. Self-sampling effectively reaches underscreened women and can be a powerful strategy in low- and high-resource settings for all target ages. This work aims to summarize the current use of HPV self-sampling worldwide. It is part of a larger project that describes cervical cancer screening programmes and produces standardized coverage estimates worldwide. A systematic review of the literature and official documents supplemented with a formal World Health Organisation country consultation was conducted. Findings show that the global use of HPV self-sampling is still limited. Only 17 (12%) of countries with identified screening programs recommend its use, nine as the primary collection method, and eight to reach underscreened populations. We identified 10 pilots evaluating the switch to self-sampling in well-established screening programs. The global use of self-sampling is likely to increase in the coming years. COVID-19's pandemic has prompted efforts to accelerate HPV self-sampling introduction globally, and it is now considered a key element in scaling up screening coverage. The information generated by the early experiences can be beneficial for decision-making in both new and existing programs

    Cervical cancer screening programmes and age-specific coverage estimates for 202 countries and territories worldwide: a review and synthetic analysis

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    Q1Q1Background: Cervical cancer screening coverage is a key monitoring indicator of the WHO cervical cancer elimination plan. We present global, regional, and national cervical screening coverage estimates against the backdrop of the 70% coverage target set by WHO. Methods: In this review and synthetic analysis, we searched scientific literature, government websites, and official documentation to identify official national recommendations and coverage data for cervical cancer screening for the 194 WHO member states and eight associated countries and territories published from database inception until Oct 30, 2020, supplemented with a formal WHO country consultation from Nov 27, 2020, to Feb 12, 2021. We extracted data on the year of introduction of recommendations, the existence of individual invitation to participate, financing of screening tests, primary screening and triage tests used, recommended ages and screening intervals, use of selfsampling, and use of screen-and-treat approaches. We also collected coverage data, either administrative or surveybased, as disaggregated as possible by age and for any available screening interval. According to data completeness and representativeness, different statistical models were developed to produce national age-specific coverages by screening interval, which were transformed into single-age datapoints. Missing data were imputed. Estimates were applied to the 2019 population and aggregated by region and income level. Findings: We identified recommendations for cervical screening in 139 (69%) of 202 countries and territories. Cytology was the primary screening test in 109 (78%) of 139 countries. 48 (35%) of 139 countries recommended primary HPV-based screening. Visual inspection with acetic acid was the most recommended test in resource-limited settings. Estimated worldwide coverage in women aged 30–49 years in 2019 was 15% in the previous year, 28% in the previous 3 years, and 32% in the previous 5 years, and 36% ever in lifetime. An estimated 1·6 billion (67%) of 2·3 billion women aged 20–70 years, including 662 million (64%) of 1·0 billion women aged 30–49 years, had never been screened for cervical cancer. 133 million (84%) of 158 million women aged 30–49 years living in high-income countries had been screened ever in lifetime, compared with 194 million (48%) of 404 million women in upper-middle-income countries, 34 million (9%) of 397 million women in lower-middle-income countries, and 8 million (11%) of 74 million in low-income countries. Interpretation: Two in three women aged 30–49 years have never been screened for cervical cancer. Roll-out of screening is very low in low-income and middle-income countries, where the burden of disease is highest. The priority of the WHO elimination campaign should be to increase both screening coverage and treatment of detected lesions; however, expanding the efforts of surveillance systems in both coverage and quality control are major challenges to achieving the WHO elimination target. Funding: Instituto de Salud Carlos III, European Regional Development Fund, Secretariat for Universities and Research of the Department of Business and Knowledge of the Government of Catalonia, and Horizon 2020.https://orcid.org/0000-0001-7187-9946Revista Internacional - IndexadaA1N

    Use of multi-layered PCM gypsums to improve fire response. Physical, thermal and mechanical characterization

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    The building sector is one of the highest energy consumers representing around 30% of total energy use. One of the recommendations of the LEA (International Energy Agency) to reduce energy consumption in buildings is to enhance the thermal performance of building envelopes. In the present study, PCM (Phase Change Material) gypsum materials have been manufactured using three different PCM inclusion methods and a thin layer of gypsum without PCM is added as external layer with the aim of improving the fire reaction behaviour. By performing a detailed physical, mechanical and thermal characterization, the suitability of the materials to be implemented in the building envelope as inner coating is demonstrated. Results show that also the thermal properties are improved in the three cases by the addition of PCM. Moreover, the negative effect of adding paraffin wax PCM into gypsum against flame can be easily reduced by the addition of a thin gypsum layer, which is a low tech and cheap solution without extra environmental impact. (C) 2016 Elsevier B.V. All rights reserved
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