2,924 research outputs found
Effectiveness of a video-feedback and questioning programme to develop cognitive expertise in sport
The importance within sport expertise of cognitive factors has been emphasised in many research studies. Adaptations that take place in athletes’ long-term memories are going to condition their decision-making and performance, and training programmes must be developed that improve these adaptations. In our study, we provide a tactical-cognitive training programme based on video-feedback and questioning in order to improve tactical knowledge in tennis players and verify its effect when transferred to athletes’ decision-making. 11 intermediate tennis players participated in this study (12.960.7 years old), distributed into two groups (experimental, n = 5; control, n = 6). Tactical knowledge was measured by problem representation and strategy planning with a verbal protocol. Decision-making was measured by a systematic observation instrument. Results confirm the effectiveness of a combination of video-feedback and questioning on cognitive expertise, developing adaptations in long-term memory that produce an improvement in the quality of tactical knowledge (content, sophistication and structure). This, in turn, is transferred to the athletes’ decision-making capacity, leading to a higher percentage of successful decisions made during game play. Finally, we emphasise the need to develop effective programmes to develop cognitive expertise and improve athletes’ performance, and include it in athletes’ formative stages
The Relative Age Effect on Soccer Players in Formative Stages with Different Sport Expertise Levels
The Relative Age Effect (RAE) in sport has been targeted by many research studies. The objective of this study was to analyze, in amateur clubs, the RAE of soccer players, according to the sport expertise level of the team (e.g., A, B, C and subsequent) that they belong to within the same game category. 1, 098 soccer players in formative stages took part in the study, with ages varying between 6 and 18 years old (U8 to U19 categories). All of them were members of 4 Spanish federated clubs. The birth dates were classified into 4 quartiles (Q1 = Jan-Mar; Q2 = Apr-Jun; Q3 = Jul-Sept; Q4 = Oct-Dec)according to the team they belonged to. The results obtained in the chi-squared test and d value (effect size) revealed the existence of RAE in the teams with the highest expertise level, "A" (X2 = 15.342, p = .002, d = 0.4473) and "B" (X2 = 10.905, p = .012, d = 0.3657). However, in the lower level teams, "C and subsequent", this effect was not observed. Present findings show that players born during the first months of the year tend to be selected to play in teams with a higher sport expertise level of each category, due to their physical maturity. Consequently, this causes differences in terms of the experience they accumulate and the motivation that this creates in these players
Implications of instructional strategies in sport teaching: a nonlinear pedagogy-based approach
In this article, we have tried to establish the practical implications of instructional strategies in sport teaching. Firstly, we have highlighted the importance of the Teaching Game for Understanding as a teaching model that is fundamentally based on the use of modified games, whose purpose is for students to learn the tactical aspects of a certain sport, by way of modified versions of the real game. Later on, we have gone further into depth into a new way of understanding the teaching-learning process in sport, non-Linear Pedagogy, which is based on manipulating the relevant determining factors (task, environment and individual) to increase information sources and thus be able to guide students towards obtaining their objectives. Within non-linear pedagogy, verbal instruction (e.g., questioning) is considered to be a determining factor that attempts to channel the search for tactical solutions within a learning environment. Finally, we end the article with a section that refers to practical applications, where we purport to give a series of guidelines on how to implement questioning as a didactical resource whose aim is to improve students’ tactical action capacity
Obstructive Sleep Apnoea Syndrome, Endothelial Function and Markers of Endothelialization. Changes after CPAP
STUDY OBJECTIVES: This study tries to assess the endothelial function in vivo using flow-mediated dilatation (FMD) and several biomarkers of endothelium formation/restoration and damage in patients with obstructive sleep apnoea (OSA) syndrome at baseline and after three months with CPAP therapy. DESIGN: Observational study, before and after CPAP therapy. SETTING AND PATIENTS: We studied 30 patients with apnoea/hypopnoea index (AHI) >15/h that were compared with themselves after three months of CPAP therapy. FMD was assessed non-invasively in vivo using the Laser-Doppler flowmetry. Circulating cell-free DNA (cf-DNA) and microparticles (MPs) were measured as markers of endothelial damage and the vascular endothelial growth factor (VEGF) was determined as a marker of endothelial restoration process. MEASUREMENTS AND RESULTS: After three month with CPAP, FMD significantly increased (1072.26 ± 483.21 vs. 1604.38 ± 915.69 PU, p< 0.005) cf-DNA and MPs significantly decreased (187.93 ± 115.81 vs. 121.28 ± 78.98 pg/ml, p<0.01, and 69.60 ± 62.60 vs. 39.82 ± 22.14 U/μL, p<0.05, respectively) and VEGF levels increased (585.02 ± 246.06 vs. 641.11 ± 212.69 pg/ml, p<0.05). These changes were higher in patients with more severe disease. There was a relationship between markers of damage (r = -0.53, p<0.005) but not between markers of damage and restoration, thus suggesting that both types of markers should be measured together. CONCLUSIONS: CPAP therapy improves FMD. This improvement may be related to an increase of endothelial restoration process and a decrease of endothelial damage
CD44-high neural crest stem-like cells are associated with tumour aggressiveness and poor survival in neuroblastoma tumours
BACKGROUND:
Neuroblastoma is a paediatric tumour originated from sympathoadrenal precursors and characterized by its heterogeneity and poor outcome in advanced stages. Intra-tumoral cellular heterogeneity has emerged as an important feature in neuroblastoma, with a potential major impact on tumour aggressiveness and response to therapy. CD44 is an adhesion protein involved in tumour progression, metastasis and stemness in different cancers; however, there has been controversies about the significance of CD44 expression in neuroblastoma and its relationship with tumour progression.
METHODS:
We have performed transcriptomic analysis on patient tumour samples studying the outcome of patients with high CD44 expression. Adhesion, invasion and proliferation assays were performed in sorted CD44high neuroblastoma cells. Tumoursphere cultures have been used to enrich in undifferentiated stem-like cells and to asses self-renewal and differentiation potential. We have finally performed in vivo tumorigenic assays on cell line-derived or Patient-derived xenografts.
FINDINGS:
We show that high CD44 expression is associated with low survival in high-grade human neuroblastoma, independently of MYCN amplification. CD44 is expressed in a cell population with neural crest stem-like features, and with the capacity to generate multipotent, undifferentiated tumourspheres in culture. These cells are more invasive and proliferative in vitro. CD44 positive cells obtained from tumours are more tumorigenic and metastatic, giving rise to aggressive neuroblastic tumours at high frequency upon transplantation.
INTERPRETATION:
We describe an unexpected intra-tumoural heterogeneity within cellular entities expressing CD44 in neuroblastoma, and propose that CD44 has a role in neural crest stem-like undifferentiated cells, which can contribute to tumorigenesis and malignancy in this type of cancer.
FUNDING:
Research supported by grants from the "Asociación Española contra el Cáncer" (AECC), the Spanish Ministry of Science and Innovation SAF program (SAF2016-80412-P), and the European Research Council (ERC Starting Grant to RP).Spanish Ministry of Science and Innovation SAF program (SAF2016-80412-P
Cuidados de enfermería en las emesis en pacientes oncohematológicos
Emesis not only the onset of vomiting associated with chemotherapy treatment but the arches and nausea, which is the feeling of desire vomiting, digestive distress and inability to retain vomiting, even When this does not occur.The main problem is that it deteriorates the quality of life of patients and even, in some cases, endangers his life. Hence the importance of its perception and treatment, although the best measure is prevention.It is one of the best known toxic effects by patients before starting treatment and one of the most feared. Therefore, this study seeks to analyze the response to antiemetic prophylaxis in the acute phase (AF) and delayed (FR) in haematological patients with chemotherapy.It includes patients treated with intravenous cytostatic between January and October 2008. 14 patients were treated, with the following diagnoses: Hodgkin lymphoma, multiple myeloma, non-Hodgkin's lymphoma and chronic lymphocytic leukemia. 84 Surveys are delivered (66 processed). Among the conclusions to be drawn is that we see a good response to chemotherapy in both FA and FR. Haematology is reviewed along with the protocol of antiemetic regimen for highly emetogenic chemotherapy in FMD, where there was 21% non-response.La emesis no es solo la aparición de vómitos relacionados con el tratamiento de la quimioterapia sino también las arcadas y las náuseas, que son la sensación del deseo de vomitar, de malestar digestivo y de incapacidad para retener el vomito; aunque este no se produzca.Su principal problema radica en que deteriora la calidad de vida del paciente e incluso, en determinados casos, compromete su vida. De ahí la importancia de percibirla y tratarla, aunque la mejor medida es la prevención.Es uno de los efectos tóxicos más conocidos por los pacientes antes de empezar el tratamiento y uno de los más temidos. Por ello, en este estudio se trata de analizar la respuesta a la profilaxis antiemética en fase aguda (FA) y retardada (FR) en pacientes hematológicos con quimioterapia.Se incluyen los pacientes tratados con citostáticos intravenosos entre Enero/Octubre 2008. Se tratan 14 pacientes con los siguientes diagnósticos: linfoma de Hodgkin, mieloma múltiple, linfoma no Hodgkin y leucemia linfoide crónica. Se entregan 84 encuestas (procesadas 66).Entre las conclusiones que se obtiene es que se aprecia una buena respuesta de los pacientes a la quimioterapia tanto en FA como FR. Se revisa junto con Hematología el protocolo de pauta antiemética para quimioterapia altamente emetógena en FA en la que se ha observado un 21% de no respuesta
Study of the Briquetting Process of Walnut Shells for Pyrolysis and Combustion
Walnut shells can be used as fuels in power plants directly or as biochars obtained by pyrolysis or torrefaction. They are an example of clean waste biomass which shows a low ash content and a high Net Calorific Value, making them excellent for energy recovery in industrial and non-industrial applications, such as in bakeries, restaurants, and homes. Their main inconvenience is their low bulk density. Densification is a possible solution that reduces the costs of transportation, handling, and storage. In this work, after the characterization of the walnut shells, briquettes were obtained using a hydraulic piston press briquette machine under different conditions to find the best quality without the need for previous grinding for pelletizing. This method features easy operation and maintenance, and the briquette shape could be adapted as desired. The quality of the briquettes was measured through their density and durability. After fixing a compaction pressure to obtain acceptable briquettes, the factors affecting their quality were studied: operating temperature, moisture content, and the presence of small amounts of walnuts. Good quality briquettes were obtained with a compaction pressure of 66 MPa, with densities around 1040 kg/m3, and durabilities higher than 94% when the process was carried at 140 °C. The greatest increase in durability was observed between briquettes obtained at room temperature and those obtained at 80 °C. The presence of small amounts of walnuts, common after the shelling process, improved the durability. Although water is necessary, briquettes obtained from biomass with only 1% of moisture showed better durabilities. Therefore, walnut shells are suitable for obtaining good quality briquettes according to the specifications of solid biofuels established in the standards, without the need for any pretreatment.This research was funded by the Agencia Estatal de Investigación (Spain) [grant number AEI/10.13039/501100011033], by the University of Alicante [grant number UAUSTI21-03] and by the Spanish Ministerio de Economia y Competividad [Research Project CTQ2016-76608-R]
Semisíntesis estereoselectiva del 3-b-D-glucósido del sitosterol, principio antihiperglucemiante de Ceutaurea seridis L. var. Maritima Lge.
The stereoselective semisynthesis conditions have been established to obtain β-sitosterol 3-β-D-glucoside, which is an antihyperglycemic principe isolated from the aerial part of Centaurea seridis L. var. maritima Lge. The yield was 11,6 per cent, much higher than the one obtained from the vegetal species, which was 0,03 per cent.Se han establecido las condiciones operatorias para la semisíntesis estereoselectiva del 3-β-D-glucósido del β -sitosterol, principio antihiperglucemiante aislado de la sumidad florida de Centaurea serídis L. varo maritima Lge. El rendimiento del proceso fue de 11,6 por ciento, netamente superior al obtenido a partir de la especie vegetal que fue 0,03 por ciento
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