430 research outputs found
An evaluation of school readiness in an informal settlement
School readiness is a stage in a child's development when he
learns easily and effectively. A child who is not yet ready for
school on school entry is already at a disadvantage in the formal
learning situation. This in itself can affect his school
performance in the later years. The researcher, being a primary
school teacher noticed that the children from the informal
settlements that had no pre-school intervention arrived at school
unready to learn.
This investigation set out to evaluate the school readiness of
children from an informal settlement without a pre-school
programme. The school readiness of these children were compared
against children from an informal settlement with a pre-school
programme. Test and questionnaires were used to determine the
five year olds' school readiness. The researcher used the
idiographic method of research.
The findings of the research were based on the interpretations
of the tests and questionnaires.Educational StudiesM. Ed. (with specialisation in Guidance and Counselling
Transferring organelles into native neurons: A disease-modifying therapy for neurodegenerative disorders
Currently, there are no disease-modifying therapies to counter the progression of neurodegenerative diseases that are associated with mitochondrial dysfunction in the early stages. In this study, we have used a novel strategy of cell fusion to transfer mitochondria from one cell to another using fusogens (syncytin 1 and syncytin 2). Syncytins are placental proteins encoded by endogenous retroviral envelope genes that promote cellular fusion. In this study, we have proposed that donor cells engineered to stably express syncytin when cocultured with recipient cells will allow fusion and facilitate the transfer of mitochondria into recipient cells. Syncytin-mediated systems revealed about 16.6-18.5% cell fusion efficiencies in N2a and SH-SY5Y cells. The present work is proof that our strategy of engineering syncytin expression systems allows cell fusion in neurons.
Keywords: neurodegeneration, mitochondria, cell fusion, syncytins, fusion efficiency, heterologous system, engineered, progression, cocultured, mitochondrial transfe
CD3- Leukocytes Present in the Human Uterus During Early Placentation: Phenotypic and Morphologic Characterization of the CD56++ Population
In this study, the CD3- LGL/NK cells present in the pregnant human uterus have been
characterized. Phenotypic and morphologic analyses of decidual LGL revealed many similarities
to the minor CD56bright+, CD16- subset in peripheral blood, but there were some
important differences. The relative surface density of CD56+ is greatly increased on decidual
LGL to 22 x that found on the majority of CD56 peripheral blood NK cells. The CD56bright
cells in decidua show LGL morphology, whereas in peripheral blood, they are .mainly
agranular. Proliferation of CD56+ cells occurs predominantly during the nonpregnant secretory
(luteal) phase, indicating these CD56+ uterine LGL do not migrate as terminally differentiated
cells. The appearance of CD56 cells was examined at the ultrastructural level using
immunoelectron microscopy. Cells with phenotypic characteristics of decidual LGL occur in
a higher percentage (1.11%) in the peripheral blood of women of reproductive age than in
men (0.66%). On the basis of these results, it is proposed that the CD56bright+ uterine leukocytes
represent a distinctive, hormonally regulated subset possibly adapted to control human
placentation
Resonant frequency in polypropylene fibre reinforced concrete (PFRC) with pozzolanic materials
In this study, the resonant frequency of polypropylene fibre reinforced concrete (PFRC) under three different curing conditions was investigated and the influences of fly ash (PFA) and silica fume (SF) on PFRC under the same curing condition were also studied. The experiments were carried out in the Heavy Laboratory of City University of Hong Kong. Four types of concrete mixes were tested. A total of 24 concrete specimens were prepared. Test results show that the resonant frequency can be affected by the presence of polypropylene fibres, partial replacement of cement by silica fume or pulverized fly ash, and curing condition.
Frist Published Online: 30 Jul 201
Phosphoinositide-dependent protein kinase-1 (PDK1)-independent activation of the protein kinase C substrate, protein kinase D
Phosphoinoisitide dependent kinase l (PDK1) is proposed to phosphorylate a key threonine residue within the catalytic domain of the protein kinase C (PKC) superfamily that controls the stability and catalytic competence of these kinases. Hence, in PDK1-null embryonic stem cells intracellular levels of PKCalpha, PKCbeta1, PKCgamma, and PKCepsilon are strikingly reduced. Although PDK1-null cells have reduced endogenous PKC levels they are not completely devoid of PKCs and the integrity of downstream PKC effector pathways in the absence of PDK1 has not been determined. In the present report, the PDK1 requirement for controlling the phosphorylation and activity of a well characterised substrate for PKCs, the serine kinase protein kinase D, has been examined. The data show that in embryonic stem cells and thymocytes loss of PDK1 does not prevent PKC-mediated phosphorylation and activation of protein kinase D. These results reveal that loss of PDK1 does not functionally inactivate all PKC-mediated signal transduction
Enhanced expression of the stemness-related factors OCT4, SOX15 and TWIST1 in ectopic endometrium of endometriosis patients
Abstract Background Current evidence suggests that endometrial-derived stem cells, spilled in the peritoneal cavity via retrograde menstruation, are key players in the establishment of endometriotic lesions. The aim of this study was to determine the presence and distribution of the stemness-related factors OCT4, SOX15, TWIST1 and DCAMLK1 in women with and without endometriosis. Methods Immunohistochemical analysis was used to determine stromal and epithelial expression of OCT4, SOX15, TWIST1 and DCAMLK1 in endometriosis patient (EP) endometrium (n = 69) and endometriotic tissue (n = 90) and in control endometrium (n = 50). Quantitative Real-Time PCR of OCT4, SOX15 TWIST1 and DCAMLK1 was performed in paired samples of EP endometrium and endometriotic tissue. Co-immunofluorescence staining was performed for OCT4 and SOX15. For statistical analyses we used unpaired t-test, Fisher combination test and Spearman test. For paired analyses, paired t-test and McNemar test were used. Results We detected a significant correlation between the expression of the established stem cell marker OCT4 and the stemness-related markers SOX15 (p < 0.001) and TWIST1 (p = 0.002) but not DCAMLK1. We showed a colocalization of SOX15 and OCT4 in epithelial and stromal cells of endometriotic tissue by coimmunofluorescence. A concordant expression of OCT4 and SOX15 in the same sample was observed in epithelial cells of the endometriotic tissue (71.7%). The expression of stemness-related factors was not associated with proliferative or secretory phase of the menstrual cycle in endometriosis patients but was found to be differentially expressed during the menstrual cycle in the control group. Increased expression of epithelial OCT4, SOX15 and TWIST1 was detected in endometriotic tissue compared to EP endometrium in paired (p = 0.021, p < 0.001 and p < 0.001) and unpaired analysis (p = 0.040, p < 0.001 and p = 0.001). Conclusion Our findings support the hypothesis that upregulation of stem cell-related factors contribute to the establishment of endometriotic lesions. Trial registration The study was approved by the institutional review board (545/2010 on 6th of May 2014) of the Medical University of Vienna ( http://ethikkommission.meduniwien.ac.at/fileadmin/ethik/media/dokumente/register/alle_2010.pdf )
Post-fire Behaviour of Innovative Shear Connection for Steel-Concrete Composite Structures
YesSteel-concrete composite structures are commonly used in buildings and bridges because it takes advantage of tensile strength of steel and compressive strength of concrete. The two components are often secured by shear connectors such as headed studs to prevent slippage and to maintain composite action. In spite of its popularity, very little research was conducted on steel-concrete composites particularly on headed stud shear connectors in regards to its post-fire behaviour. This research investigates the post-fire behaviour of innovative shear connectors for composite steel and concrete. Three type of connectors were investigated. They are headed stud shear connectors, Blind Bolt 1 and Blind Bolt 2 blind bolts. Push-out test experimental studies were conducted to look at the behaviour and failure modes for each connector. Eighteen push tests were conducted according to Eurocode 4. The push test specimens were tested under ambient temperatures and post fire condition of 200ËšC, 400ËšC and 600ËšC. The results in ambient temperature are used to derive the residual strength of shear connectors after exposing to fire. Findings from this research will provide fundamental background in designing steel-concrete composites where there is danger of fire exposure
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CD3- leukocytes present in the human uterus during early placentation: phenotypic and morphologic characterization of the CD56++ population.
In this study, the CD3- LGL/NK cells present in the pregnant human uterus have been characterized. Phenotypic and morphologic analyses of decidual LGL revealed many similarities to the minor CD56bright+, CD16- subset in peripheral blood, but there were some important differences. The relative surface density of CD56+ is greatly increased on decidual LGL to 22x that found on the majority of CD56+ peripheral blood NK cells. The CD56bright+ cells in decidua show LGL morphology, whereas in peripheral blood, they are mainly agranular. Proliferation of CD56+ cells occurs predominantly during the nonpregnant secretory (luteal) phase, indicating these CD56+ uterine LGL do not migrate as terminally differentiated cells. The appearance of CD56+ cells was examined at the ultrastructural level using immunoelectron microscopy. Cells with phenotypic characteristics of decidual LGL occur in a higher percentage (1.11%) in the peripheral blood of women of reproductive age than in men (0.66%). On the basis of these results, it is proposed that the CD56bright+ uterine leukocytes represent a distinctive, hormonally regulated subset possibly adapted to control human placentation.Peer Reviewe
Sleep loss drives acetylcholine- and somatostatin interneuron-mediated gating of hippocampal activity to inhibit memory consolidation
Sleep loss disrupts consolidation of hippocampus-dependent memory. To characterize effects of learning and sleep loss, we quantified activity-dependent phosphorylation of ribosomal protein S6 (pS6) across the dorsal hippocampus of mice. We find that pS6 is enhanced in dentate gyrus (DG) following single-trial contextual fear conditioning (CFC) but is reduced throughout the hippocampus after brief sleep deprivation (SD; which disrupts contextual fear memory [CFM] consolidation). To characterize neuronal populations affected by SD, we used translating ribosome affinity purification sequencing to identify cell type-specific transcripts on pS6 ribosomes (pS6-TRAP). Cell type-specific enrichment analysis revealed that SD selectively activated hippocampal somatostatin-expressing (Sst+) interneurons and cholinergic and orexinergic hippocampal inputs. To understand the functional consequences of SD-elevated Sst+ interneuron activity, we used pharmacogenetics to activate or inhibit hippocampal Sst+ interneurons or cholinergic input from the medial septum. The activation of either cell population was sufficient to disrupt sleep-dependent CFM consolidation by gating activity in granule cells. The inhibition of either cell population during sleep promoted CFM consolidation and increased S6 phosphorylation among DG granule cells, suggesting their disinhibition by these manipulations. The inhibition of either population across post-CFC SD was insufficient to fully rescue CFM deficits, suggesting that additional features of sleeping brain activity are required for consolidation. Together, our data suggest that state-dependent gating of DG activity may be mediated by cholinergic input and local Sst+ interneurons. This mechanism could act as a sleep loss-driven inhibitory gate on hippocampal information processing.</p
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