370 research outputs found
Moving from a discourse of access to reading instructional materials to the management and utilisation thereof : Progress International Reading Literature Study at Grade 4 in South Africa
Two cycles of the Progress in International Reading Literacy Study (PIRLS)
were completed in South Africa in 2006 and 2011. In this article, we investigate
the qualities of high-performing reading literacy schools for optimal resource management and utilisation strategies for possible application to low-performing
schools. We do this against the background of reports on reading resource
shortages and inadequacies in the context of reading literacy learning from
both of the PIRLS main studies. This is done by comparing six case study
schools with varying contexts and performance levels. The findings from a
secondary analysis using the PIRLS 2006 data together with six case studies
using international reading benchmarks from PIRLS 2006 to depict performance
levels, confirmed that learners in low-performing schools from the study had
inadequate access to reading instruction resources. This appeared partly
attributable to inadequate funding and government provisioning; ineffective
resource management at school level and non-resourcefulness of teachers
at classroom level exacerbating reading resource inadequacies; as well as
ineffective utilisation of materials at these low-performing schools. The resource
management and utilisation strategies of high-performing case study schools
were found to be potential models for schools with inadequate strategies.http://www.unisa.ac.za/default.asp?Cmd=ViewContent&ContentID=2008http://www.journals.co.za/content/journal/mousaion2017-12-30am2017Curriculum Studie
Potential Export of Unattached Benthic Macroalgae to the Deep Sea Through Wind Driven Langmuir Circulation
Carbon export to the deep sea is conventionally attributed to the sinking of open ocean phytoplankton. Here, we report a Langmuir supercell event driven by high winds across the shallow Great Bahama Bank that organized benthic non-attached macroalgae, Colpomenia sp., into visible windrows on the seafloor. Ocean color satellite imagery obtained before and after the windrows revealed a 588 km2 patch that rapidly shifted from highly productive macroalgae to bare sand. We assess a number of possible fates for this macroalgae and contend that this event potentially transported negatively buoyant macroalgae to the deep Tongue of the Ocean in a pulsed export of \u3e 7 x 1010 g of carbon. This is equivalent to the daily carbon flux of phytoplankton biomass in the pelagic tropical North Atlantic and 0.2-0.8% of daily carbon flux from the global ocean. Coastal banks and bays are highly productive ecosystems that may contribute substantially to carbon export to the deep sea. Citation: Dierssen, H. M., R. C. Zimmerman, L. A. Drake, and D. J. Burdige (2009), Potential export of unattached benthic macroalgae to the deep sea through wind-driven Langmuir circulation, Geophys. Res. Lett., 36, L04602, doi: 10.1029/2008GL036188
Benthic Ecology From Space: Optics and Net Primary Production in Seagrass and Benthic Algae Across the Great Bahama Bank
Development of repeatable and quantitative tools are necessary for determining the abundance and distribution of different types of benthic habitats, detecting changes to these ecosystems, and determining their role in the global carbon cycle. Here we used ocean color remote sensing techniques to map different major groups of primary producers and estimate net primary productivity (NPP) across Great Bahama Bank (GBB). Field investigations on the northern portion of the GBB in 2004 revealed 3 dominant types of benthic primary producers: seagrass, benthic macroalgae, and microalgae attached to sediment. Laboratory measurements of NPP ranged from barely net autotrophic for grapestone sediment with thin microalgal biofilm to highly productive for dense accumulations of brown macroalgae. A logarithmic relationship between NPP and green seafloor reflectance described the general trend in NPP across various benthic constituents. Using a radiative transfer-based approach, satellite-derived estimates of NPP for the region totaled similar to ~2 x 1013 gC yrĖĀ¹ across the GBB. The prevailing benthic habitat was mapped as sediment with little to no microalgal biofilm. Moderate to dense seagrass meadows of Thalassia testudinumwere the dominant primary producers and contributed over 80% of NPP in the region. If the vast majority of seagrass leaves decompose in the primarily carbonate sediments, carbonate dissolution processes associated with this decomposition may result in sequestration of seagrass above- and below-ground carbon into the bicarbonate pool (2.4 x 1013 gC yrĖĀ¹), where it has a residence time on the order of tens of thousands of years
Setting standards and primary school teachers' experiences of the process
In South Africa, very few standard-setting exercises are carried out in education and, if they are, teachers are not involved in their execution. As a result, there is no clear understanding of what the standard is and how it was arrived at. This situation is compounded when teachers are held accountable when learners do not meet the prescribed standards. The aim of this paper is to explore how teachers experienced a standard-setting process and if any reflection on teaching and learning practices took place. The research question addressed is: How was the SAMP standard-setting exercise experienced by teachers? Standard setting is an important component in monitoring systems whether national or school-based monitoring systems. The South African Monitoring system for Primary Schools (SAMP) is a school-based monitoring system. The Grade 1 SAMP assessment is administered in English, Afrikaans and Sepedi. As part of SAMP, a standard-setting exercise was undertaken for the Grade 1 assessment to better inform the dissemination of performance results to schools. As part of a bigger research project, a participatory qualitative approach was followed in which 27 participants were asked to partake in a modified Interactive Qualitative Analysis (IQA) process. Several themes were identified by the teachers, namely reflections on practice; emotions before and during the standard setting workshop; benefits of working in a group; and improvements in the process. In this article, these themes are explored and their relevance for standard setting within school contexts discussed.Tthe National Research Foundation (NRF) and the
South Africa Netherlands Research Programme on Alternatives in Development
(SANPAD).http://www.perspectives-in-education.comam2014gv201
Network-assisted protein identification and data interpretation in shotgun proteomics
Protein assembly and biological interpretation of the assembled protein lists are critical steps in shotgun proteomics data analysis. Although most biological functions arise from interactions among proteins, current protein assembly pipelines treat proteins as independent entities. Usually, only individual proteins with strong experimental evidence, that is, confident proteins, are reported, whereas many possible proteins of biological interest are eliminated. We have developed a clique-enrichment approach (CEA) to rescue eliminated proteins by incorporating the relationship among proteins as embedded in a protein interaction network. In several data sets tested, CEA increased protein identification by 8ā23% with an estimated accuracy of 85%. Rescued proteins were supported by existing literature or transcriptome profiling studies at similar levels as confident proteins and at a significantly higher level than abandoned ones. Applying CEA on a breast cancer data set, rescued proteins coded by well-known breast cancer genes. In addition, CEA generated a network view of the proteins and helped show the modular organization of proteins that may underpin the molecular mechanisms of the disease
C. elegans serine-threonine kinase KIN-29 modulates TGFĪ² signaling and regulates body size formation
BACKGROUND: In C. elegans there are two well-defined TGFĪ²-like signaling pathways. The Sma/Mab pathway affects body size morphogenesis, male tail development and spicule formation while the Daf pathway regulates entry into and exit out of the dauer state. To identify additional factors that modulate TGFĪ² signaling in the Sma/Mab pathway, we have undertaken a genetic screen for small animals and have identified kin-29. RESULTS: kin-29 encodes a protein with a cytoplasmic serine-threonine kinase and a novel C-terminal domain. The kinase domain is a distantly related member of the EMK (ELKL motif kinase) family, which interacts with microtubules. We show that the serine-threonine kinase domain has in vitro activity. kin-29 mutations result in small animals, but do not affect male tail morphology as do several of the Sma/Mab signal transducers. Adult worms are smaller than the wild-type, but also develop more slowly. Rescue by kin-29 is achieved by expression in neurons or in the hypodermis. Interaction with the dauer pathway is observed in double mutant combinations, which have been seen with Sma/Mab pathway mutants. We show that kin-29 is epistatic to the ligand dbl-1, and lies upstream of the Sma/Mab pathway target gene, lon-1. CONCLUSION: kin-29 is a new modulator of the Sma/Mab pathway. It functions in neurons and in the hypodermis to regulate body size, but does not affect all TGFĪ² outputs, such as tail morphogenesis
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Construction of the model for the Genetic Analysis Workshop 14 simulated data...
The Genetic Analysis Workshop 14 simulated dataset was designed 1) To test the ability to find genes related to a complex disease (such as alcoholism). Such a disease may be given a variety of definitions by different investigators, have associated endophenotypes that are common in the general population, and is likely to be not one disease but a heterogeneous collection of clinically similar, but genetically distinct, entities. 2) To observe the effect on genetic analysis and gene discovery of a complex set of gene Ć gene interactions. 3) To allow comparison of microsatellite vs. large-scale single-nucleotide polymorphism (SNP) data. 4) To allow testing of association to identify the disease gene and the effect of moderate marker Ć marker linkage disequilibrium. 5) To observe the effect of different ascertainment/disease definition schemes on the analysis. Data was distributed in two forms. Data distributed to participants contained about 1,000 SNPs and 400 microsatellite markers. Internet-obtainable data consisted of a finer 10,000 SNP map, which also contained data on controls. While disease characteristics and parameters were constant, four "studies" used varying ascertainment schemes based on differing beliefs about disease characteristics. One of the studies contained multiplex two- and three-generation pedigrees with at least four affected members. The simulated disease was a psychiatric condition with many associated behaviors (endophenotypes), almost all of which were genetic in origin. The underlying disease model contained four major genes and two modifier genes. The four major genes interacted with each other to produce three different phenotypes, which were themselves heterogeneous. The population parameters were calibrated so that the major genes could be discovered by linkage analysis in most datasets. The association evidence was more difficult to calibrate but was designed to find statistically significant association in 50% of datasets. We also simulated some marker Ć marker linkage disequilibrium around some of the genes and also in areas without disease genes. We tried two different methods to simulate the linkage disequilibrium
Reconsidering frameworks of Alzheimerās dementia when assessing psychosocial outcomes
The purpose of this introductory article to the special issue on psychosocial outcome measures in Alzheimerās & Dementia: Translational Research & Clinical Interventions is to outline new frameworks to more effectively capture and measure the full range of how people living with Alzheimerās dementia and their family caregivers experience the disease process. Specifically, we consider the strengths and weaknesses of alternative perspectives, including personācentered, strengthābased, and resilienceāfocused approaches that may complement and extend the dominant deficit paradigm to reflect the entirety of the dementia experience. Our aim is to encourage innovative methods to measure psychosocial aspects of Alzheimerās dementia and caregiving that have not yet received sufficient attention, including resources (e.g., services and supports) and positive caregiver and care recipient outcomes (e.g., positive mood and adaptation).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152840/1/trc2jtrci201902008.pd
Geocoding rural addresses in a community contaminated by PFOA: a comparison of methods
BACKGROUND: Location is often an important component of exposure assessment, and positional errors in geocoding may result in exposure misclassification. In rural areas, successful geocoding to a street address is limited by rural route boxes. Communities have assigned physical street addresses to rural route boxes as part of E911 readdressing projects for improved emergency response. Our study compared automated and E911 methods for recovering and geocoding valid street addresses and assessed the impact of positional errors on exposure classification. METHODS: The current study is a secondary analysis of existing data that included 135 addresses self-reported by participants of a rural community study who were exposed via public drinking water to perfluorooctanoate (PFOA) released from a DuPont facility in Parkersburg, West Virginia. We converted pre-E911 to post-E911 addresses using two methods: automated ZP4 address-correction software with the U.S. Postal Service LACS database and E911 data provided by Wood County, West Virginia. Addresses were geocoded using TeleAtlas, an online commercial service, and ArcView with StreetMap Premium North America NAVTEQ 2008 enhanced street dataset. We calculated positional errors using GPS measurements collected at each address and assessed exposure based on geocoded location in relation to public water pipes. RESULTS: The county E911 data converted 89% of the eligible addresses compared to 35% by ZP4 LACS. ArcView/NAVTEQ geocoded more addresses (n = 130) and with smaller median distance between geocodes and GPS coordinates (39 meters) than TeleAtlas (n = 85, 188 meters). Without E911 address conversion, 25% of the geocodes would have been more than 1000 meters from the true location. Positional errors in TeleAtlas geocoding resulted in exposure misclassification of seven addresses whereas ArcView/NAVTEQ methods did not misclassify any addresses. CONCLUSIONS: Although the study was limited by small numbers, our results suggest that the use of county E911 data in rural areas increases the rate of successful geocoding. Furthermore, positional accuracy of rural addresses in the study area appears to vary by geocoding method. In a large epidemiological study investigating the health effects of PFOA-contaminated public drinking water, this could potentially result in exposure misclassification if addresses are incorrectly geocoded to a street segment not serviced by public water
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