170 research outputs found
Trends in KCPE Performance: Their Function in School Effectiveness and Improvement in Gitugi Education Zone Murang’a County, Kenya
This research sought to find out whether and how the analysis of the mean scores as utilized in Gitugi zone impact on the schools’ effectiveness and improvement with regard to performance in KCPE. The research had three objectives, namely) to determine whether there is any significant difference between the KCPE mean scores among the schools,ii) to determine whether there is any significant difference between the KCPE mean scores among cohorts and,iii) to find out whether or how summative and formative evaluation can be used to improve performance in KCPE in Gitugi education zone. Nine out of the fifteen schools were chosen through systematic random sampling. Document analysis was done for both the summative KCPE results and the formative evaluation in class eight, 2011. Piloting was done in one school in the zone. The data collected is presented in tables and graphs and, analyzed using inferential statistics using one-way analysis of variance (ANOVA) and Spearman’s Rank correlation coefficient. The schools show a downward trend in performance in KCPE in the zone except two from 2007 to 2011. There is significant difference in the KCPE means among the nine schools, while there is no significant difference across cohorts. This ANOVA results point to differences between schools which need further investigation to explain the observed consistent differences in KCPE performance. Annual calculations of mean scores and ranking continue to generate anxiety without addressing the causative agents. It is recommended that analysis of trends in KCPE performance should be embraced as a useful tool in examining the differences among schools and cohorts and also used to develop strategies to raise schools’ effectiveness geared towards enhancement of KCPE scores in Gitugi education zone, Murang’a County, Kenya. [281 words] Keywords: trends in KCPE performance, ranking of schools, schools’ effectiveness, schools’ improvemen
One and Two Dimensional Pulsed Electron Paramagnetic Resonance Studies of in vivo Vanadyl Coordination in Rat Kidney
The biological fate of a chelated vanadium source is investigated by/n vivo spectroscopic methods to
elucidate the chemical form in which the metal ion is accumulated. A pulsed electron paramagnetic
resonance study of vanadyl ions in kidney tissue, taken from rats previously treated with
bis(ethylmaltolato)oxovanadium(IV) (BEOV) in drinking water, is presented. A combined approach using
stimulated echo (3-pulse) electron spin echo envelope modulation (ESEEM) and the two dimensional 4-pulse
hyperfine sublevel correlation (HYSCORE) spectroscopies has shown that at least some of the VO2+ ions are
involved in the coordination with nitrogen-containing ligands. From the experimental spectra, a 4N hyperfine
coupling constant of 4.9 MHz and a quadrupole coupling constant of 0.6 + 0.04 MHz were determined,
consistent with amine coordination of the vanadyl ions. Study of VO-histidine model complexes allowed for
a determination of the percentage of nitrogen-coordinated VO2+ ions in the tissue sample that is found
nitrogen-coordinated. By taking into account the bidentate nature of histidine coordination to VO2+ ions, a
more accurate determination of this value is reported. The biological fate of chelated versus free (i.e. salts) vanadyl ion sources has been deduced by comparison to earlier reports. In contrast to its superior pharmacological efficacy over VOSO4, BEOV shares a remarkably similar biological fate after uptake into kidney tissue
UV-Optical Pixel Maps of Face-On Spiral Galaxies -- Clues for Dynamics and Star Formation Histories
UV and optical images of the face-on spiral galaxies NGC 6753 and NGC 6782
reveal regions of strong on-going star formation that are associated with
structures traced by the old stellar populations. We make NUV--(NUV-I) pixel
color-magnitude diagrams (pCMDs) that reveal plumes of pixels with strongly
varying NUV surface brightness and nearly constant I surface brightness. The
plumes correspond to sharply bounded radial ranges, with (NUV-I) at a given NUV
surface brightness being bluer at larger radii. The plumes are parallel to the
reddening vector and simple model mixtures of young and old populations, thus
neither reddening nor the fraction of the young population can produce the
observed separation between the plumes. The images, radial surface-brightness,
and color plots indicate that the separate plumes are caused by sharp declines
in the surface densities of the old populations at radii corresponding to disk
resonances. The maximum surface brightness of the NUV light remains nearly
constant with radius, while the maximum I surface brightness declines sharply
with radius. An MUV image of NGC 6782 shows emission from the nuclear ring. The
distribution of points in an (MUV-NUV) vs. (NUV-I) pixel color-color diagram is
broadly consistent with the simple mixture model, but shows a residual trend
that the bluest pixels in (MUV-NUV) are the reddest pixels in (NUV-I). This may
be due to a combination of red continuum from late-type supergiants and [SIII]
emission lines associated with HII regions in active star-forming regions. We
have shown that pixel mapping is a powerful tool for studying the distribution
and strength of on-going star formation in galaxies. Deep, multi-color imaging
can extend this to studies of extinction, and the ages and metallicities of
composite stellar populations in nearby galaxies.Comment: LaTeX with AASTeX style file, 29 pages with 12 figures (some color,
some multi-part). Accepted for publication in The Astrophysical Journa
Street-Level Diplomacy and Local Enforcement for Meat Safety in Northern Tanzania: Kowledge, Pragmatism and Trust
With increasing demand for red meat in Tanzania comes heightened potential for zoonotic infections
in animals and humans that disproportionately affect poor communities. A range of frontline government employees work to protect public health, providing services for people engaged in animal-based livelihoods (livestock owners and butchers), and enforcing meat safety and food premises standards. In contrast to literature which emphasises the inadequacy of extension support and food safety policy implementation in low- and middle-income countries, this paper foregrounds the ‘street-level diplomacy’ deployed by frontline actors operating in challenging contexts
An HST Survey of the mid-UV Morphology of Nearby Galaxies
(Abbreviated) We present an imaging survey of 37 nearby galaxies observed
with HST/WFPC2 in the mid-UV F300W filter and in F814W. 11 galaxies were also
imaged in F255W. These galaxies were selected to be detectable with WFPC2 in
one orbit, and cover a wide range of Hubble types and inclinations. The mid-UV
spans the gap between our groundbased optical/NIR images and far-UV images
available from the Astro/UIT missions. Our first qualitative results are:
(1) Early-type galaxies show a significant decrease in surface brightness
going from the red to the mid-UV, and in some cases the presence of dust lanes.
Some galaxies would be classified different when viewed in the mid-UV, some
become dominated by a blue nuclear feature or point source.
(2) Half of the mid-type spiral and star-forming galaxies appear as a later
morphological type in the mid-UV, as Astro/UIT also found in the far-UV. Some-
times these differences are dramatic. The mid-UV images show a considerable
range in the scale and surface brightness of individual star-forming regions.
Almost all mid-type spirals have their small bulges bi-sected by a dust-lane.
(3) Most of the heterogeneous subset of late-type, irregular, peculiar, and
merging galaxies display F300W morphologies that are similar to those seen in
F814W, but with differences due to recognizable dust features absorbing the
bluer light, and due to UV-bright hot stars, star-clusters, and star-forming
ridges.
In the rest-frame mid-UV, early- to mid-type galaxies are more likely to be
misclassified as later types than vice versa. This morphological K-correction
explains only part of the excess faint blue galaxies seen in deep HST fields.Comment: 30 pages, LateX (AASTeX5.0), 2 figures and 3 tables included, mid-UV
atlas and pan-chromatic atlas provided as 63 JPG figures. Full resolution PS
version (~100Mb) available upon request. Accepted for publication in ApJ
Bed net use and associated factors in a rice farming community in Central Kenya
<p>Abstract</p> <p>Background</p> <p>Use of insecticide-treated nets (ITNs) continues to offer potential strategy for malaria prevention in endemic areas. However their effectiveness, sustainability and massive scale up remain a factor of socio-economic and cultural variables of the local community which are indispensable during design and implementation stages.</p> <p>Methods</p> <p>An ethnographic household survey was conducted in four study villages which were purposefully selected to represent socio-economic and geographical diversity. In total, 400 households were randomly selected from the four study villages. Quantitative and qualitative information of the respondents were collected by use of semi-structured questionnaires and focus group discussions.</p> <p>Results</p> <p>Malaria was reported the most frequently occurring disease in the area (93%) and its aetiology was attributed to other non-biomedical causes like stagnant water (16%), and long rains (13%). Factors which significantly caused variation in bed net use were occupant relationship to household head (χ<sup>2 </sup>= 105.705; df 14; P = 0.000), Age (χ<sup>2 </sup>= 74.483; df 14; P = 0.000), village (χ<sup>2 </sup>= 150.325; df 6; P = 0.000), occupation (χ<sup>2 </sup>= 7.955; df 3; P = 0.047), gender (χ<sup>2 </sup>= 4.254; df 1; P = 0.039) and education levels of the household head or spouse (χ<sup>2 </sup>= 33.622; df 6; P = 0.000). The same variables determined access and conditions of bed nets at household level. Protection against mosquito bite (95%) was the main reason cited for using bed nets in most households while protection against malaria came second (54%). Colour, shape and affordability were some of the key potential factors which determined choice, use and acceptance of bed nets in the study area.</p> <p>Conclusion</p> <p>The study highlights potential social and economic variables important for effective and sustainable implementation of bed nets-related programmes in Sub-Saharan Africa.</p
Malaria vector control practices in an irrigated rice agro-ecosystem in central Kenya and implications for malaria control
<p>Abstract</p> <p>Background</p> <p>Malaria transmission in most agricultural ecosystems is complex and hence the need for developing a holistic malaria control strategy with adequate consideration of socio-economic factors driving transmission at community level. A cross-sectional household survey was conducted in an irrigated ecosystem with the aim of investigating vector control practices applied and factors affecting their application both at household and community level.</p> <p>Methods</p> <p>Four villages representing the socio-economic, demographic and geographical diversity within the study area were purposefully selected. A total of 400 households were randomly sampled from the four study villages. Both semi-structured questionnaires and focus group discussions were used to gather both qualitative and quantitative data.</p> <p>Results</p> <p>The results showed that malaria was perceived to be a major public health problem in the area and the role of the vector <it>Anopheles </it>mosquitoes in malaria transmission was generally recognized. More than 80% of respondents were aware of the major breeding sites of the vector. Reported personal protection methods applied to prevent mosquito bites included; use of treated bed nets (57%), untreated bed nets (35%), insecticide coils (21%), traditional methods such as burning of cow dung (8%), insecticide sprays (6%), and use of skin repellents (2%). However, 39% of respondents could not apply some of the known vector control methods due to unaffordability (50.5%), side effects (19.9%), perceived lack of effectiveness (16%), and lack of time to apply (2.6%). Lack of time was the main reason (56.3%) reported for non-application of environmental management practices, such as draining of stagnant water (77%) and clearing of vegetations along water canals (67%).</p> <p>Conclusion</p> <p>The study provides relevant information necessary for the management, prevention and control of malaria in irrigated agro-ecosystems, where vectors of malaria are abundant and disease transmission is stable.</p
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
Acute exercise induces distinct quantitative and phenotypical T cell profiles in men with prostate cancer
BackgroundReduced testosterone levels can influence immune system function, particularly T cells. Exercise during cancer reduces treatment-related side effects and provide a stimulus to mobilize and redistribute immune cells. However, it is unclear how conventional and unconventional T cells (UTC) respond to acute exercise in prostate cancer survivors compared to healthy controls.MethodsAge-matched prostate cancer survivors on androgen deprivation therapy (ADT) and those without ADT (PCa) along with non-cancer controls (CON) completed ∼45 min of intermittent cycling with 3 min at 60% of peak power interspersed by 1.5 min of rest. Fresh, unstimulated immune cell populations and intracellular perforin were assessed before (baseline), immediately following (0 h), 2 h, and 24 h post-exercise.ResultsAt 0 h, conventional T cell counts increased by 45%–64% with no differences between groups. T cell frequency decreased by −3.5% for CD3+ and −4.5% for CD4+ cells relative to base at 0 h with CD8+ cells experiencing a delayed decrease of −4.5% at 2 h with no group differences. Compared to CON, the frequency of CD8+CD57+ cells was −18.1% lower in ADT. Despite a potential decrease in maturity, ADT increased CD8+perforin+ GMFI. CD3+Vα7.2+CD161+ counts, but not frequencies, increased by 69% post-exercise while CD3+CD56+ cell counts increased by 127% and were preferentially mobilized (+1.7%) immediately following the acute cycling bout. There were no UTC group differences. Cell counts and frequencies returned to baseline by 24 h.ConclusionFollowing acute exercise, prostate cancer survivors demonstrate normal T cell and UTC responses that were comparable to CON. Independent of exercise, ADT is associated with lower CD8+ cell maturity (CD57) and perforin frequency that suggests a less mature phenotype. However, higher perforin GMFI may attenuate these changes, with the functional implications of this yet to be determined
Enhanced articular cartilage by human mesenchymal stem cells in enzymatically mediated transiently RGDS-functionalized collagen-mimetic hydrogels
Recapitulation of the articular cartilage microenvironment for regenerative medicine applications faces significant challenges due to the complex and dynamic biochemical and biomechanical nature of native tissue. Towards the goal of biomaterial designs that enable the temporal presentation of bioactive sequences, recombinant bacterial collagens such as Streptococcal collagen-like 2 (Scl2) proteins can be employed to incorporate multiple specific bioactive and biodegradable peptide motifs into a single construct. Here, we first modified the backbone of Scl2 with glycosaminoglycan-binding peptides and cross-linked the modified Scl2 into hydrogels via matrix metalloproteinase 7 (MMP7)-cleavable or non-cleavable scrambled peptides. The cross-linkers were further functionalized with a tethered RGDS peptide creating a system whereby the release from an MMP7-cleavable hydrogel could be compared to a system where release is not possible. The release of the RGDS peptide from the degradable hydrogels led to significantly enhanced expression of collagen type II (3.9-fold increase), aggrecan (7.6-fold increase), and SOX9 (5.2-fold increase) by human mesenchymal stem cells (hMSCs) undergoing chondrogenesis, as well as greater extracellular matrix accumulation compared to non-degradable hydrogels (collagen type II; 3.2-fold increase, aggrecan; 4-fold increase, SOX9; 2.8-fold increase). Hydrogels containing a low concentration of the RGDS peptide displayed significantly decreased collagen type I and X gene expression profiles, suggesting a major advantage over either hydrogels functionalized with a higher RGDS peptide concentration, or non-degradable hydrogels, in promoting an articular cartilage phenotype. These highly versatile Scl2 hydrogels can be further manipulated to improve specific elements of the chondrogenic response by hMSCs, through the introduction of additional bioactive and/or biodegradable motifs. As such, these hydrogels have the possibility to be used for other applications in tissue engineering. Statement of Significance Recapitulating aspects of the native tissue biochemical microenvironment faces significant challenges in regenerative medicine and tissue engineering due to the complex and dynamic nature of the tissue. The ability to take advantage of, mimic, and modulate cell-mediated processes within novel naturally-derived hydrogels is of great interest in the field of biomaterials to generate constructs that more closely resemble the biochemical microenvironment and functions of native biological tissues such as articular cartilage. Towards this goal, the temporal presentation of bioactive sequences such as RGDS on the chondrogenic differentiation of human mesenchymal stem cells is considered important as it has been shown to influence the chondrogenic phenotype. Here, a novel and versatile platform to recreate a high degree of biological complexity is proposed, which could also be applicable to other tissue engineering and regenerative medicine applications
- …