59 resultados para Generation of test processes
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
This multi-phase study examined the influence of retrieval processes on children’s metacognitive processes in relation to and in interaction with achievement level and age. First, N = 150 9/10- and 11/12-year old high and low achievers watched an educational film and predicted their test performance. Children then solved a cloze test regarding the film content including answerable and unanswerable items and gave confidence judgments to every answer. Finally, children withdrew answers that they believed to be incorrect. All children showed adequate metacognitive processes before and during test taking with 11/12- year-olds outperforming 9/10-year-olds when considering characteristics of on-going retrieval processes. As to the influence of achievement level, high compared to low achievers proved to be more accurate in their metacognitive monitoring and controlling. Results suggest that both cognitive resources (operationalized through achievement level) and mnemonic experience (assessed through age) fuel metacognitive development. Nevertheless, when facing higher demands regarding retrieval processes, experience seems to play the more important role.
Resumo:
Abstract: Research on human values within the family focuses on value congruence between the family members (Knafo & Schwartz, 2004), based on the assumption that transmission of values is part of a child’s socialization process. Within the family, values are not only implicitly transmitted through this process but also explicitly conveyed through the educational goals of parents (Grusec et al., 2000; Knafo & Schwartz, 2003; 2004, 2009). However, there is a lack of empirical evidence on the role of family characteristics in the value transmission process, especially for families with young children. Thus, the study presented had multiple aims: Firstly, it analyzed the congruency between mothers’ and fathers’ values and their value-based educational goals. Secondly, it examined the influence of mothers’ and fathers’ socio-demographic characteristics on their educational goals. Thirdly, it analyzed the differences in parental educational goals in families with daughters and families with sons. Finally, it examined the congruency between children’s values and the value-based educational goals of their parents. The value transmission process within families with young children was analyzed using data from complete families (child, mother and father) in Switzerland (N = 265). The survey of children consisted of 139 boys and 126 girls aged between 7 and 9 years. Parents’ values and parental educational goals were assessed using the Portrait Value Questionnaire (PVQ-21) (Schwartz, 2005). Children’s’ values were assessed using the Picture-Based Value Survey for Children (PBVS-C) (Döring et al., 2010). Regarding the role of the family context in the process of shaping children’s values, the results of the study show that, on average, parents are similar not only with respect to their value profiles but also with regard to their notion as to which values they would like to transmit to their children. Our findings also suggest that children’s values at an early age are shaped more strongly by mothers’ values than by fathers’ values. Moreover, our results show differences in value transmission with respect to the child’s gender. In particular, they suggest that value transmission within the family has a greater influence on female than on male offspring.
Resumo:
The precise timing of events in the brain has consequences for intracellular processes, synaptic plasticity, integration and network behaviour. Pyramidal neurons, the most widespread excitatory neuron of the neocortex have multiple spike initiation zones, which interact via dendritic and somatic spikes actively propagating in all directions within the dendritic tree. For these neurons, therefore, both the location and timing of synaptic inputs are critical. The time window for which the backpropagating action potential can influence dendritic spike generation has been extensively studied in layer 5 neocortical pyramidal neurons of rat somatosensory cortex. Here, we re-examine this coincidence detection window for pyramidal cell types across the rat somatosensory cortex in layers 2/3, 5 and 6. We find that the time-window for optimal interaction is widest and shifted in layer 5 pyramidal neurons relative to cells in layers 6 and 2/3. Inputs arriving at the same time and locations will therefore differentially affect spike-timing dependent processes in the different classes of pyramidal neurons.
Resumo:
BACKGROUND Detection of HIV-1 p24 antigen permits early identification of primary HIV infection and timely intervention to limit further spread of the infection. Principally, HIV screening should equally detect all viral variants, but reagents for a standardised test evaluation are limited. Therefore, we aimed to create an inexhaustible panel of diverse HIV-1 p24 antigens. METHODS We generated a panel of 43 recombinantly expressed virus-like particles (VLPs), containing the structural Gag proteins of HIV-1 subtypes A-H and circulating recombinant forms (CRF) CRF01_AE, CRF02_AG, CRF12_BF, CRF20_BG and group O. Eleven 4th generation antigen/antibody tests and five antigen-only tests were evaluated for their ability to detect VLPs diluted in human plasma to p24 concentrations equivalent to 50, 10 and 2 IU/ml of the WHO p24 standard. Three tests were also evaluated for their ability to detect p24 after heat-denaturation for immune-complex disruption, a pre-requisite for ultrasensitive p24 detection. RESULTS Our VLP panel exhibited an average intra-clade p24 diversity of 6.7%. Among the 4th generation tests, the Abbott Architect and Siemens Enzygnost Integral 4 had the highest sensitivity of 97.7% and 93%, respectively. Alere Determine Combo and BioRad Access were least sensitive with 10.1% and 40.3%, respectively. Antigen-only tests were slightly more sensitive than combination tests. Almost all tests detected the WHO HIV-1 p24 standard at a concentration of 2 IU/ml, but their ability to detect this input for different subtypes varied greatly. Heat-treatment lowered overall detectability of HIV-1 p24 in two of the three tests, but only few VLPs had a more than 3-fold loss in p24 detection. CONCLUSIONS The HIV-1 Gag subtype panel has a broad diversity and proved useful for a standardised evaluation of the detection limit and breadth of subtype detection of p24 antigen-detecting tests. Several tests exhibited problems, particularly with non-B subtypes.
Resumo:
Autophagy has been demonstrated to have an essential function in several cellular hematopoietic differentiation processes, for example, the differentiation of reticulocytes. To investigate the role of autophagy in neutrophil granulopoiesis, we studied neutrophils lacking autophagy-related (Atg) 5, a gene encoding a protein essential for autophagosome formation. Using Cre-recombinase mediated gene deletion, Atg5-deficient neutrophils showed no evidence of abnormalities in morphology, granule protein content, apoptosis regulation, migration, or effector functions. In such mice, however, we observed an increased proliferation rate in the neutrophil precursor cells of the bone marrow as well as an accelerated process of neutrophil differentiation, resulting in an accumulation of mature neutrophils in the bone marrow, blood, spleen, and lymph nodes. To directly study the role of autophagy in neutrophils, we employed an in vitro model of differentiating neutrophils that allowed modulating the levels of ATG5 expression, or, alternatively, intervening pharmacologically with autophagy-regulating drugs. We could show that autophagic activity correlated inversely with the rate of neutrophil differentiation. Moreover, pharmacological inhibition of p38 MAPK or mTORC1 induced autophagy in neutrophilic precursor cells and blocked their differentiation, suggesting that autophagy is negatively controlled by the p38 MAPK-mTORC1 signaling pathway. On the other hand, we obtained no evidence for an involvement of the PI3K-AKT or ERK1/2 signaling pathways in the regulation of neutrophil differentiation. Taken together, these findings show that, in contrast to erythropoiesis, autophagy is not essential for neutrophil granulopoiesis, having instead a negative impact on the generation of neutrophils. Thus, autophagy and differentiation exhibit a reciprocal regulation by the p38-mTORC1 axis.
Resumo:
The first generation of the everolimus-eluting bioresorbable vascular scaffold (BVS 1.0) showed an angiographic late loss higher than the metallic everolimus-eluting stent Xience V due to scaffold shrinkage. The new generation (BVS 1.1) presents a different design and manufacturing process than the BVS 1.0. This study sought to evaluate the differences in late shrinkage, neointimal response, and bioresorption process between these two scaffold generations using optical coherence tomography (OCT).
Resumo:
The first generation of the bioresorbable everolimus drug-eluting vascular scaffold showed signs of shrinkage at 6 months, which largely contributed to late luminal loss. Nevertheless, late luminal loss was less than that observed with bare metal stents. To maintain the mechanical integrity of the device up to 6 months, the scaffold design and manufacturing process of its polymer were modified.
Resumo:
Prosthesis-patient mismatch (PPM) remains a controversial issue with the most recent stented biological valves. We analyzed the incidence of PPM after implantation of the Carpentier-Edwards Perimount Magna Ease aortic valve (PMEAV) bioprosthesis and assessed the early clinical outcome. Two hundred and seventy consecutive patients who received a PMEAV bioprosthesis between January 2007 and July 2008 were analyzed. Pre-, peri- and postoperative data were assessed and echocardiographic as well as clinical follow-up was performed. Mean age was 72+/-9 years, 168 (62.2%) were males. Fifty-seven patients (21.1%) were below 65 years of age. Absence of PPM, corresponding to an indexed effective orifice area >0.85 cm(2)/m(2), was 99.5%. Observed in-hospital mortality was 2.2% (six patients), with a predicted mortality according to the additive EuroSCORE of 7.6+/-3.1%. At echocardiographic assessment after a mean follow-up period of 150+/-91 days, mean transvalvular gradient was 11.8+/-4.8 mmHg (all valve sizes). No paravalvular leakage was seen. Nine patients died during follow-up. The Carpentier-Edwards PMEAV bioprosthesis shows excellent hemodynamic performance. This valve can be implanted in all sizes with an incidence of severe PPM below 0.5%.
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The objective of the study was to determine the feasibility of generating a biodegradable, stem cell-loaded osteogenic composite graft from human placenta. Initially, a scaffold from human chorion membrane was produced. Human placenta mesenchymal stem cells (MSCs) derived from either first-trimester chorionic villi or term chorion membrane were differentiated osteogenically on this scaffold. Outgrowth, adherence, and osteogenic differentiation of cells were assessed by immunohistochemistry (IHC), scanning electron microscopy, protein expression, and real-time polymerase chain reaction (RT-PCR). Our results showed that a cell-free extracellular matrix scaffold can be generated from human chorion. Seeded MSCs densely adhered to that scaffold and were osteogenically differentiated. Calcium and alkaline phosphatase were detected in the cell-scaffold constructs as a proof of mineralization and findings were confirmed by IHC and RT-PCR results. This study shows for the first time that generation of an osteogenic composite graft using placental tissue is feasible. It might allow therapeutic application of autologous or allogeneic grafts in congenital skeletal defects by means of a composite graft.
Resumo:
Vessel angulation and large changes in vessel geometry after stent implantation have been associated with an increased risk of target lesion failure (TLF) using bare-metal stents. Second-generation drug-eluting stents (DES)offer superior conformability and inhibition of neointima. The aim of the study is to investigate the relationship between pre and post-implant vessel geometry and the occurrence of TLF at 1 year after treatment with second-generation DES; and to compare the conformability of Resolute and Xience stents.
Resumo:
The aim of this study was to demonstrate that the prevention of early scaffold area shrinkage of the ABSORB BVS (Rev.1.1, Abbott Vascular, Santa Clara, California) was sustained and not simply delayed by a few months.
Resumo:
The aim of this study is to assess the serial changes in strut apposition and coverage of the bioresorbable vascular scaffolds (BVS) and to relate this with the presence of intraluminal masses at 6 months with optical coherence tomography (OCT).