224 research outputs found

    Microinclusions in cassiterite of different deposits in western Spain

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    [Resumen] Se incluyen en este estudio casiteritas procedentes de distintos yacimientos de Salamanca y Extremadura que se han seleccionado en función de sus diferentes caracteres: hábito, color, zonaci6n, tipología genética y composición química. Se presenta la descripción microscópica así como la composición química obtenida mediante microsonda de las casiteritas y sus microinclusiones. Cabe destacar una clara relación entre la razón Nb/Ta y el tipo genético. Por otro lado, la razón Fe/Mn es característica propia del ambiente geoquímico de cada yacimiento. Las casiteritas ricas en Nb y Ta contienen microinclusiones de columbo-tantalita, las casiteritas ricas en Ti y Nb, ilmeno-rutilo y columbo-tantalita y las esencialmente, titaníferas , rutilos.[Abstract] Cassiterites of different deposits in western Spain were selectioned for this study by different characteristics: colour, crystal habit, zonation, genetic type and chemical composition. Microscopic description and Microprobe analysis of cassiterites and microinclusions are presented. There is correlation between columbite-tantalite composition (Nb/Ta) and the genetic type; on the other hand, Fe/Mn depends of geochemical enviroment in ore deposits formation. The Nb-Ta cassiterites contain microinclusions of columbite-tantalite, the Ti-Nb cassiterites microinclusions of ilmeno-rutile and columbite-Tantalite and the Ti-cassiterites, rutiles

    Distribución de elementos menores y trazas en casiteritas de distintos tipos de yacimientos españoles

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    [Resumen] En este trabajo se presenta, por primera vez, la composición química de muestras de casi teri tas pertenecientes a distintos tipos de yacimientos españoles, local izados a lo largo del Macizo Hespérico. Se establecen correlaciones entre los caracteres geoquímicos y genéticos, así como, entre el hábito y el color con la tipología del yacimiento: Bipirámides de tonalidades oscuras, junto con una escasa ó nula maclación, son típicas de los depósitos de diseminación y pegmatíticos. Prismas apuntados en pirámides, con una extensa gama de color y abundante maclación I son característicos de yacimientos filonianos.[Abstract] This study presents the chemical composi tion of cassi teri tes samples from different kinds of Spanish deposi ts, for first time. The correlations between geochemical and genetic characteristics are presented, and also, between habi t and colour wi th the type of deposit: Bipyramids of dark tonali ties wi th a li ttle or null twining are characteristic of dissemination and pegmati tic deposits. Pointed prims in pyramid wi th a wide range of colours and abundant twining are characteristic of lode deposit

    Multi-resolution low-power Gaussian filtering by reconfigurable focal-plane binning

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    Gaussian filtering is a basic tool for image processing. Noise reduction, scale-space generation or edge detection are examples of tasks where different Gaussian filters can be successfully utilized. However, their implementation in a conventional digital processor by applying a convolution kernel throughout the image is quite inefficient. Not only the value of every single pixel is taken into consideration sucessively, but also contributions from their neighbors need to be taken into account. Processing of the frame is serialized and memory access is intensive and recurrent. The result is a low operation speed or, alternatively, a high power consumption. This inefficiency is specially remarkable for filters with large variance, as the kernel size increases significantly. In this paper, a different approach to achieve Gaussian filtering is proposed. It is oriented to applications with very low power budgets. The key point is a reconfigurable focal-plane binning. Pixels are grouped according to the targeted resolution by means of a division grid. Then, two consecutive shifts of this grid in opposite directions carry out the spread of information to the neighborhood of each pixel in parallel. The outcome is equivalent to the application of a 3×3 binomial filter kernel, which in turns is a good approximation of a Gaussian filter, on the original image. The variance of the closest Gaussian filter is around 0.5. By repeating the operation, Gaussian filters with larger variances can be achieved. A rough estimation of the necessary energy for each repetition until reaching the desired filter is below 20nJ for a QCIF-size array. Finally, experimental results of a QCIF proofof- concept focal-plane array manufactured in 0.35μm CMOS technology are presented. A maximum RMSE of only 1.2% is obtained by the on-chip Gaussian filtering with respect to the corresponding equivalent ideal filter implemented off-chip.Junta de Andalucía 2006-TIC-2352Ministerio de Ciencia e Innovación TEC 2009-11812Office of Naval Research (USA) N00014111031

    Effect of Exercise on Inflammation in Hemodialysis Patients: A Systematic Review

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    Background: In recent years, physical exercise has been investigated for its potential as a therapeutic tool in patients with end-stage renal disease (ESRD) undergoing hemodialysis maintenance treatment (HD). It has been shown that regular practice of moderate-intensity exercise can improve certain aspects of immune function and exert anti-inflammatory effects, having been associated with low levels of pro-inflammatory cytokines and high levels of anti-inflammatory cytokines. Purpose: The aim of this review is to examine the studies carried out in this population that analyzed the effect of intradialytic exercise on the inflammatory state and evaluate which exercise modality is most effective. Methods: The search was carried out in the MEDLINE, CINAHL Web of Science and Cochrane Central Register of Controlled Trials databases from inception to June 2022. The PEDro scale was used to assess methodological quality, and the Cochrane Risk of Bias Tool and MINORS were used to evaluate the risk of bias. The quality of evidence was assessed with GRADE scale. The outcome measures were systemic inflammation biomarkers. Results: Mixed results were found in terms of improving inflammation biomarkers, such as CRP, IL-6 or TNFα, after exercise. Aerobic exercise seems to improve systemic inflammation when performed at medium intensity while resistance training produced better outcomes when performed at high intensity. However, some studies reported no differences after exercise and these results should be taken with caution. Conclusions: The low quality of the evidence suggests that aerobic and resistance exercise during HD treatment improves systemic inflammation biomarkers in patients with ESRD. In any case, interventions that increase physical activity in patients with ESRD are of vital importance as sedentary behaviors are associated with mortality. More studies are needed to affirm solid conclusions and to make intervention parameters, such as modality, dose, intensity or duration, sufficiently clear

    Role of subterranean microbiota in the carbon cycle and greenhouse gas dynamics

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    Subterranean ecosystems play an active role in the global carbon cycle, yet only a few studies using indirect methods have focused on the role of the cave microbiota in this critical cycle. Here we present pioneering research based on in situ real-time monitoring of CO2 and CH4 diffusive fluxes and concurrent δ13C geochemical tracing in caves, combined with 16S microbiome analysis. Our findings show that cave sediments are promoting continuous CH4 consumption from cave atmosphere, resulting in a significant removal of 65% to 90%. This research reveals the most effective taxa and metabolic pathways in consumption and uptake of greenhouse gases. Methanotrophic bacteria were the most effective group involved in CH4 consumption, namely within the families Methylomonaceae, Methylomirabilaceae and Methylacidiphilaceae. In addition, Crossiella and Nitrosococcaceae wb1-P19 could be one of the main responsible of CO2 uptake, which occurs via the Calvin-Benson-Bassham cycle and reversible hydration of CO2. Thus, syntrophic relationships exist between Crossiella and nitrifying bacteria that capture CO2, consume inorganic N produced by heterotrophic ammonification in the surface of sediments, and induce moonmilk formation. Moonmilk is found as the most evolved phase of the microbial processes in cave sediments that fixes CO2 as calcite and intensifies CH4 oxidation. From an ecological perspective, cave sediments act qualitatively as soils, providing fundamental ecosystem services (e.g. nutrient cycling and carbon sequestration) with direct influence on greenhouse gas emissions.This work was supported by the Spanish Ministry of Science, Innovation through project PID2019-110603RB-I00, MCIN/AEI/FEDER, UE/10.13039/501100011033 and with collaboration of projects RTI2018-099052-B-I00 and PID2020-114978GB-I00. This research has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 844535 — MIFLUKE

    Efficacy of Manual Therapy on Facilitatory Nociception and Endogenous Pain Modulation in Older Adults with Knee Osteoarthritis: A Case Series.

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    Background: manual therapy (MT) has been shown to have positive effects in patients with osteoarthritis (OA)-related pain, and its use in clinical settings is recommended. However, the mechanisms of action for how these positive effects occur are not yet well understood. The aim of the present study was to investigate the influence of MT treatment on facilitatory nociception and endogenous pain modulation in patients with knee OA related pain. Methods: Twenty-eight patients with knee OA were included in this study. Pain intensity using the numerical pain rating scale (NPRS), temporal summation (TS), conditioned pain modulation (CPM), and local (knee) and distant (elbow) hyperalgesia through the pressure pain threshold (PPT), were assessed to evaluate the pain modulatory system. Patients underwent four sessions of MT treatments within 3 weeks and were evaluated at the baseline, after the first session and after the fourth session. Results: the MT treatment reduced knee pain after the first session (p = 0.03) and after the fourth session (p = 0.04). TS decreased significantly after the fourth session of MT (p = 0.02), while a significant increase in the CPM assessment was detected after the fourth session (p = 0.05). No significant changes in the PPT over the knee and elbow were found in the follow-ups. Conclusions: The results from our study suggest that MT might be an effective and safe method for improving pain and for decreasing temporal summation.post-print502 K

    Delineating reef fish trophic guilds with global gut content data synthesis and phylogeny

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    Understanding species' roles in food webs requires an accurate assessment of their trophic niche. However, it is challenging to delineate potential trophic interactions across an ecosystem, and a paucity of empirical information often leads to inconsistent definitions of trophic guilds based on expert opinion, especially when applied to hyperdiverse ecosystems. Using coral reef fishes as a model group, we show that experts disagree on the assignment of broad trophic guilds for more than 20% of species, which hampers comparability across studies. Here, we propose a quantitative, unbiased, and reproducible approach to define trophic guilds and apply recent advances in machine learning to predict probabilities of pairwise trophic interactions with high accuracy. We synthesize data from community-wide gut content analyses of tropical coral reef fishes worldwide, resulting in diet information from 13,961 individuals belonging to 615 reef fish. We then use network analysis to identify 8 trophic guilds and Bayesian phylogenetic modeling to show that trophic guilds can be predicted based on phylogeny and maximum body size. Finally, we use machine learning to test whether pairwise trophic interactions can be predicted with accuracy. Our models achieved a misclassification error of less than 5%, indicating that our approach results in a quantitative and reproducible trophic categorization scheme, as well as high-resolution probabilities of trophic interactions. By applying our framework to the most diverse vertebrate consumer group, we show that it can be applied to other organismal groups to advance reproducibility in trait-based ecology. Our work thus provides a viable approach to account for the complexity of predator-prey interactions in highly diverse ecosystems.Peer reviewe

    Process evaluation in the field: global learnings from seven implementation research hypertension projects in low-and middle-income countries

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    Background Process evaluation is increasingly recognized as an important component of effective implementation research and yet, there has been surprisingly little work to understand what constitutes best practice. Researchers use different methodologies describing causal pathways and understanding barriers and facilitators to implementation of interventions in diverse contexts and settings. We report on challenges and lessons learned from undertaking process evaluation of seven hypertension intervention trials funded through the Global Alliance of Chronic Diseases (GACD). Methods Preliminary data collected from the GACD hypertension teams in 2015 were used to inform a template for data collection. Case study themes included: (1) description of the intervention, (2) objectives of the process evaluation, (3) methods including theoretical basis, (4) main findings of the study and the process evaluation, (5) implications for the project, policy and research practice and (6) lessons for future process evaluations. The information was summarized and reported descriptively and narratively and key lessons were identified. Results The case studies were from low- and middle-income countries and Indigenous communities in Canada. They were implementation research projects with intervention arm. Six theoretical approaches were used but most comprised of mixed-methods approaches. Each of the process evaluations generated findings on whether interventions were implemented with fidelity, the extent of capacity building, contextual factors and the extent to which relationships between researchers and community impacted on intervention implementation. The most important learning was that although process evaluation is time consuming, it enhances understanding of factors affecting implementation of complex interventions. The research highlighted the need to initiate process evaluations early on in the project, to help guide design of the intervention; and the importance of effective communication between researchers responsible for trial implementation, process evaluation and outcome evaluation. Conclusion This research demonstrates the important role of process evaluation in understanding implementation process of complex interventions. This can help to highlight a broad range of system requirements such as new policies and capacity building to support implementation. Process evaluation is crucial in understanding contextual factors that may impact intervention implementation which is important in considering whether or not the intervention can be translated to other contexts
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