783 research outputs found
Design of a Bubble Reactor for Altitude Simulators Used to Humidify a Combustion Air Stream by Means of CFD Multi-Phase Models
[EN] In this paper, a procedure for the design of a bubble reactor which allows the control of the humidity of a gas stream used as combustion air is presented. This reactor is designed to be used as a component of an altitude simulator test facility for the optimization, homologation and calibration of new hybrid engines. The design has been carried out by means of Computational Fluid Dynamics (CFD) multi-phase models and validated against the experimental data obtained from the developed prototype. A discussion about the adequate mesh topology and cell size is presented, as well as a comparison between the two available models for the air-water interphase. Lastly, a validation of the CFD results using experimental data shows that the model that should be used is the multi-regime interaction model, from which the final design for the bubble reactor was obtained.This research has been partially supported by Universitat Politecnica de Valencia through project PAID-01-18.Serrano, J.; Gil, A.; Quintero-Igeño, P.; Tabet-Aleixandre, R.; Gómez, J. (2021). Design of a Bubble Reactor for Altitude Simulators Used to Humidify a Combustion Air Stream by Means of CFD Multi-Phase Models. Applied Sciences. 11(1):1-15. https://doi.org/10.3390/app11010295S11511
A hybrid tgfu/se volleyball teaching unit for enhancing motivation in physical education: A mixed-method approach
Grounded in self-determination theory, this pre-experimental study analyzed the effects of a hybrid teaching games for understanding/sport education (TGfU/SE) volleyball teaching unit on students’ motivational outcomes, using a mixed-method approach. It also examined whether the intervention was equally effective for boys and girls. Participants were 53 secondary school students (Mage = 15.50, SDage = 0.57) who were taught through a hybrid TGfU/SE unit. The structure of this unit was designed according to the characteristics of SE model, while learning tasks were designed by using the pedagogical principles of TGfU model. Both self-reported validated questionnaires and focus groups were used before and after intervention to assess students’ motivational responses. After the hybrid TGfU/SE unit, both quantitative and qualitative findings showed improvements in students’ perceptions of need-support from the physical education (PE) teacher, basic psychological needs satisfaction, novelty, and variety satisfaction, as well as intrinsic motivation compared to baseline values. Although the hybrid TGfU/SE unit was effective in both genders, a large effect size was found for girls. Despite the existence of social and cultural stereotypes in team sports such as volleyball in favor of boys, results highlight the importance of developing hybrid TGfU/SE units to improve students’ motivational outcomes, especially in girls
Voluntary and community groups and health professionals contribution to selfmanagement and wellbeing
¿Qué modelo de supervision es más útil para guiar a los estudiantes de doctorado? La perspectiva española
Educating our early career researchers is becoming far more difficult. The model of supervision should be flexible and adjusted along the way. There is not a universal model that is beneficial for all the student-supervisor relationships. It is important to find which model is more suitable depending on the stage of the PhD (1-4 year) but also the characteristics of both PhD student and supervisor. Becoming an effective supervisor requires training. Higher research institutions should implement strategies and plans of action to enhance the supervision skills of their staff. This work analyses the PhD student perspective about which model of supervision is considered as the most suitable in Spain
Tratamiento asistido por artroscopia de las fracturas de radio distal
ResumenLa artroscopia proporciona una valoración directa de la superficie articular y permite detectar lesiones asociadas en las fracturas de la extremidad distal del radio. Su incorporación al tratamiento de estas fracturas ha supuesto un mejor control de la reducción de los trazos articulares, pero se trata de una técnica compleja que aún no está generalizada entre la mayoría de los cirujanos ortopédicos y/o de la mano y la muñeca.Se realiza una revisión y actualización de las ventajas, las indicaciones, las claves técnicas, los resultados y los datos científicos de su utilidad para el tratamiento de las fracturas del radio distal.AbstractArthroscopy provides a direct evaluation of the joint surface and enables associated injuries to be detected in fractures of the distal end of the radius. Although its incorporation into the treatment of these fractures has led to a better control in the reduction of joint traces, it is a complicated technique that is still not in general use by the majority of orthopaedic and/or hand and wrist surgeons.A review is presented here, as well as an update of the advantages, indications, the key techniques, results, and scientific data of its use in the treatment of distal radius fractures
Guillain–Barré syndrome associated with leptomeningeal enhancement following SARS-CoV-2 infection
INTRODUCTION: Patients with coronavirus disease 2019 (COVID-19) typically present with respiratory symptoms, but little is known about the disease''s potential neurological complications.We report a case of Guillain-Barré syndrome (GBS) following a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, in association with leptomeningeal enhancement. CASE PRESENTATION: A 56-year-old woman presented with recent unsteadiness and paraesthesia in both hands. Fifteen days earlier, she complained of fever, dry cough and shortness of breath. Her chest X-ray showed a lobar consolidation and PCR was positive for SARS-CoV-2; she was admitted due to mild COVID-19 pneumonia.In the first 48 hours of hospitalisation, she started to experience lumbar pain and weakness of the proximal lower extremities, progressing to bilateral facial nerve palsy, oropharyngeal weakness and severe proximal tetraparesis with cervical flexion 2/5 on the MRC scale. Full spine magnetic resonance imaging (MRI) showed a brainstem and cervical leptomeningeal enhancement. Analysis of cerebrospinal fluid (CSF) revealed albumin-cytological dissociation. Microbiological studies on CSF, including SARS-CoV-2, were negative. Nerve conduction studies were consistent with demyelinating neuropathy. She was treated with intravenous immunoglobulin, with significant neurological improvement noted over the next 2 weeks. CONCLUSION: Leptomeningeal enhancement is an atypical feature in GBS, but could be a marker of its association with SARS-CoV-2 infection
Morphometric and microstructural characteristics of hippocampal subfields in mesial temporal lobe epilepsy and their correlates with mnemonic discrimination.
Pattern separation (PS) is a fundamental aspect of memory creation that defines the ability to transform similar memory representations into distinct ones, so they do not overlap when storing and retrieving them. Experimental evidence in animal models and the study of other human pathologies have demonstrated the role of the hippocampus in PS, in particular of the dentate gyrus (DG) and CA3. Patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HE) commonly report mnemonic deficits that have been associated with failures in PS. However, the link between these impairments and the integrity of the hippocampal subfields in these patients has not yet been determined. The aim of this work is to explore the association between the ability to perform mnemonic functions and the integrity of hippocampal CA1, CA3, and DG in patients with unilateral MTLE-HE.
To reach this goal we evaluated the memory of patients with an improved object mnemonic similarity test. We then analyzed the hippocampal complex structural and microstructural integrity using diffusion weighted imaging.
Our results indicate that patients with unilateral MTLE-HE present alterations in both volume and microstructural properties at the level of the hippocampal subfields DG, CA1, CA3, and the subiculum, that sometimes depend on the lateralization of their epileptic focus. However, none of the specific changes was found to be directly related to the performance of the patients in a pattern separation task, which might indicate a contribution of various alterations to the mnemonic deficits or the key contribution of other structures to the function.
we established for the first time the alterations in both the volume and the microstructure at the level of the hippocampal subfields in a group of unilateral MTLE patients. We observed that these changes are greater in the DG and CA1 at the macrostructural level, and in CA3 and CA1 in the microstructural level. None of these changes had a direct relation to the performance of the patients in a pattern separation task, which suggests a contribution of various alterations to the loss of function
Mapping habitat loss in the deep-sea using current and past presences of Isidella elongata (Cnidaria: Alcyonacea)
The bamboo coral Isidella elongata is an engineering species that forms a characteristic biogenic habitat in the bathyal mud of the Mediterranean Sea. This habitat has been severely reduced in recent decades due to trawling impacts, and there is a growing concern about its conservation status. In this work, the habitat loss of I. elongata was computed using a novel approach that combines the realized niche of the species with the estimation of its past distribution (before trawling) to delineate potential areas of habitat loss with different levels of uncertainty. The realized niche of the species was modelled using only live colonies and including trawling effort as explanatory variable whereas the past distribution was estimated also using the leftovers of dead colonies as presences. Trawling effort had a statistically significant negative effect on the extent of the realized niche of I. elongata, confirming previous results on the impact of this pressure on its distribution. The novel approach used in this work has allowed us to map for the first time several areas of potential habitat loss for I. elongata in the studied area, opening new opportunities to provide this essential information for future management and restoration actions of vulnerable marine ecosystems worldwide.Versión del editor2,27
Diabetes self-management arrangements in Europe: a realist review to facilitate a project implemented in six countries
Background: Self-management of long term conditions can promote quality of life whilst delivering benefits to the financing of health care systems. However, rarely are the meso-level influences, likely to be of direct relevance to these desired outcomes, systematically explored. No specific international guidelines exist suggesting the features of the most appropriate structure and organisation of health care systems within which to situate self-management approaches and practices. This review aimed to identify the quantitative literature with regard to diabetes self-management arrangements currently in place within the health care systems of six countries (The United Kingdom, The Netherlands, Norway, Spain, Bulgaria, and Greece) and explore how these are integrated into the broader health care and welfare systems in each country.
Methods: The methodology for a realist review was followed. Publications of interest dating from 2000 to 2013 were identified through appropriate MeSH terms by a systematic search in six bibliographic databases. A search diary was maintained and the studies were assessed for their quality and risk of bias.
Results: Following the multi-step search strategy, 56 studies were included in the final review (the majority from the UK) reporting design methods and findings on 21 interventions and programmes for diabetes and chronic disease self-management. Most (11/21, 52%) of the interventions were designed to fit within the context of primary care. The majority (11/21, 52%) highlighted behavioural change as an important goal. Finally, some (5/21, 24%) referred explicitly to Internet-based tools.
Conclusions: This review is based on results which are derived from a total of at least 5,500 individuals residing in the six participating countries. It indicates a policy shift towards patient-centred self-management of diabetes in a primary care context. The professional role of diabetes specialist nurses, the need for multidisciplinary approaches and a focus on patient education emerge as fundamental principles in the design of relevant programmes. Socio-economic circumstances are relevant to the capacity to self-manage and suggest that any gains and progress will be hard to maintain during economic austerity. This realist review should be interpreted within the wider context of a whole systems approach regarding self-care support and chronic illness management
Time course and association of functional and biochemical markers in severe semitendinosus damage following intensive eccentric leg curls: differences between and within subjects
Purpose: To investigate the extent and evolution of hamstring muscle damage caused by an intensive bout of eccentric leg curls (ELCs) by (1) assessing the time course and association of different indirect markers of muscle damage such as changes in the force-generating capacity (FGC), functional magnetic resonance (fMRI), and serum muscle enzyme levels and (2) analyzing differences in the degree of hamstring muscle damage between and within subjects (limb-to-limb comparison). Methods: Thirteen male participants performed six sets of 10 repetitions of an ELC with each leg. Before and at regular intervals over 7 days after the exercise, FGC was measured with maximal isometric voluntary contraction (MVC). Serum enzyme levels, fMRI transverse relaxation time (T2) and perceived muscle soreness were also assessed and compared against the FGC. Results: Two groups of subjects were identified according to the extent of hamstring muscle damage based on decreased FGC and increased serum enzyme levels: high responders (n = 10, severe muscle damage) and moderate responders (n = 3, moderate muscle damage). In the high responders, fMRI T2 analysis revealed that the semitendinosus (ST) muscle suffered severe damage in the three regions measured (proximal, middle, and distal). The biceps femoris short head (BFsh) muscle was also damaged and there were significant differences in the FGC within subjects in the high responders. Conclusion: FGC and serum enzyme levels measured in 10 of the subjects from the sample were consistent with severe muscle damage. However, the results showed a wide range of peak MVC reductions, reflecting different degrees of damage between subjects (high and moderate responders). fMRI analysis confirmed that the ST was the hamstring muscle most damaged by ELCs, with uniform T2 changes across all the measured sections of this muscle. During intensive ELCs, the ST muscle could suffer an anomalous recruitment pattern due to fatigue and damage, placing an excessive load on the BFsh and causing it to perform a synergistic compensation that leads to structural damage. Finally, T2 and MVC values did not correlate for the leg with the smaller FGC decrease in the hamstring muscles, suggesting that long-lasting increases in T2 signals after FGC markers have returned to baseline values might indicate an adaptive process rather than damage
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