530 research outputs found
Embodied learning in the classroom: Effects on primary school childrenâs attention and foreign language vocabulary learning
Objectives: The aim of the present study was to investigate the effects of specifically designed physical activities
on primary school childrenâs foreign language vocabulary learning and attentional performance.
Design: A total of 104 children aged between 8 and 10 years were assigned to either (a) an embodied learning
condition consisting of task-relevant physical activities, (b) a physical activity condition involving task-irrelevant
physical activities, or (c) a control condition consisting of a sedentary teaching style. Within a 2-week teaching
program, consisting of four learning sessions, children had to learn 20 foreign language words.
Method: Children were tested on their memory performance (cued r
p35, the non-cyclin activator of Cdk5, protects podocytes against apoptosis in vitro and in vivo
Cyclin-dependent kinase-5 is widely expressed and predominantly regulated by the non-cyclin activator p35. Since we recently showed that expression of p35 in the kidney is restricted to podocytes, we examined here its function in mice in which p35 was genetically deleted. The mice did not exhibit kidney abnormalities during glomerular development or during adult life. Conditionally immortalized cultured podocytes, derived from these null mice, did not have any change in their morphology, differentiation, or proliferation. However, when these cultured podocytes were exposed to UV-C irradiation, serum depletion, puromycin aminonucleoside, or transforming growth factor-β-1, they showed increased apoptosis compared to those from wild-type mice. Levels of Bcl-2 were decreased in these null podocytes but increased after transduction with human p35. Restoration of p35 or the ectopic expression of Bcl-2 reduced the susceptibility of p35-null podocytes to apoptosis. Experimental glomerulonephritis, characterized by podocyte apoptosis and subsequent crescent formation, was utilized to test these findings in vivo. Podocyte apoptosis was significantly increased in diseased p35-null compared with wild-type mice, accompanied by increased glomerulosclerosis and decreased renal function. Our study shows that p35 does not affect glomerulogenesis but controls podocyte survival following injury, in part, by regulating Bcl-2 expression
In planta expression of human polyQ-expanded huntingtin fragment reveals mechanisms to prevent disease-related protein aggregation
In humans, aggregation of polyglutamine repeat (polyQ) proteins causes disorders such as Huntingtonâs disease. Although plants express hundreds of polyQ-containing proteins, no pathologies arising from polyQ aggregation have been reported. To investigate this phenomenon, we expressed an aggregation-prone fragment of human huntingtin (HTT) with an expanded polyQ stretch (Q69) in Arabidopsis thaliana plants. In contrast to animal models, we find that Arabidopsis sp. suppresses Q69 aggregation through chloroplast proteostasis. Inhibition of chloroplast proteostasis diminishes the capacity of plants to prevent cytosolic Q69 aggregation. Moreover, endogenous polyQ-containing proteins also aggregate on chloroplast dysfunction. We find tha
Urea concentration on vegetative development and nutrition of Cactaceae epiphytic species
Functional role of T-cell receptor nanoclusters in signal initiation and antigen discrimination
Antigen recognition by the T-cell receptor (TCR) is a hallmark of the adaptive immune system. When the TCR engages a peptide bound to the restricting major histocompatibility complex molecule (pMHC), it transmits a signal via the associated CD3 complex. How the extracellular antigen recognition event leads to intracellular phosphorylation remains unclear. Here, we used single-molecule localization microscopy to quantify the organization of TCRâCD3 complexes into nanoscale clusters and to distinguish between triggered and nontriggered TCRâCD3 complexes. We found that only TCRâCD3 complexes in dense clusters were phosphorylated and associated with downstream signaling proteins, demonstrating that the molecular density within clusters dictates signal initiation. Moreover, both pMHC dose and TCRâpMHC affinity determined the density of TCRâCD3 clusters, which scaled with overall phosphorylation levels. Thus, TCRâCD3 clustering translates antigen recognition by the TCR into signal initiation by the CD3 complex, and the formation of dense signaling-competent clusters is a process of antigen discrimination
Tubulohelical membrane arrays: From the initial observation to the elucidation of nanophysical properties and cellular function
Lipids undergo self-assembly to form ordered nonlamellar, nanoperiodic arrays both in vitro and in vivo. While engineering of such membrane arrays for technical devices is envisaged, we know little about their cellular function. Do they represent building blocks of an inherent cellular nanotechnology? Prospects for answering this question could be improved if the nanophysical properties of the membrane arrays could be studied in the context of specific cellular functions. Therefore, we draw attention to exceptional complex membrane arrays found in the renal epithelial cell line PtK2 that could provide perfect conditions for both biophysical and cell functional studies. The so-called tubulohelical membrane arrays (TUHMAs) combine nanoperiodicity of lipid membranes with that of helix-like proteinaceous core structures. Strikingly, they show several characteristics of dynamic, microtubule-associated single organelles. Our initial data indicate that TUHMA formation occurs in the depth of the cytoplasm under participation of cytoplasmic nucleoporins. Once matured, they may fuse with the nuclear membrane in polarized positions, either perpendicularly or in parallel to the nucleus. As a starting point for the initiation of functional studies we found a connection between TUHMAs and primary cilia, indicated by immunolabeling patterns of detyrosynated tubulin and cytoplasmic nucleoporins. We discuss these observations in the context of the ciliary cycle and of the specific requirement of ciliated renal epithelial cells for oriented cell division. Finally, we raise the question of whether putative nanooptical properties of TUHMAs could serve for communicating orientation between dividing cells
Plant structure predicts leaf litter capture in the tropical montane bromeliad Tillandsia turneri
Efeitos da umidade do solo e da cobertura vegetal na distribuição e abundância de Drosera montana (Droseraceae)
Novel study design to assess the utility of the copd assessment test in a primary care setting
The quality of a consultation provided by a physician can have a profound impact on the quality of care and
patient engagement in treatment decisions. When the COPD Assessment Test (CAT) was developed, one of its aims
was to aid the communication between physician and patient about the impact of COPD. We developed a novel
study design to assess this in a primary care consultation.
Primary care physicians across five countries in Europe conducted videoed consultations with six standardised
COPD patients (played by trained actors) which had patient-specific issues that the physician needed to identify
through questioning. Half the physicians saw the patients with the completed CAT, and half without. Independent
assessors scored the physicians on their ability to identify and address the patient-specific issues, review standard COPD aspects, their understanding of the case and their overall performance. This novel study design presented
many challenges which needed to be addressed to achieve an acceptable level of robustness to assess the utility of
the CAT. This paper discusses these challenges and the measures adopted to eliminate or minimise their impact on
the study results
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