2,637 research outputs found
Cost Should Be No Barrier: An Evaluation of the First Year of Harvard\u27s Financial Aid Initiative
This paper evaluates the first year of Harvardâs Financial Aid Initiative, which increased aid and recruiting for students from low income backgrounds. Using rich data from the Census and administrative sources, we estimate family incomes for the vast majority of plausible applicants from the U.S. We find that the Initiative had a significant effect almost entirely because it attracted a pool of applicants that was larger and slightly poorer. It appears that very similar standards of admission were used for this group as had been used in previous years. This group, once admitted, enrolled at a rate very similar to that of previous years. Thus, there are a greater number of low income students in the Class of 2009 than in the Class of 2008 simply because more well-qualified, low income students applied. Put another way, the initiative did not create a new form of affirmative actionârather, there was an untapped supply of able, low income students. Many apparently qualified students still do not apply, and a disproportionate share of these âmissing applicantsâ come from high schools that have little or no tradition of sending applications to selective private colleges. Targeted outreach to such âone offsâ â that is, students who are one of only a few qualified students from their school in recent years â may be a way for selective private colleges to increase their income diversity
Cost Should Be No Barrier: An Evaluation of the First Year of Harvard's Financial Aid Initiative
This paper evaluates the first year of Harvard's Financial Aid Initiative, which increased aid and recruiting for students from low income backgrounds. Using rich data from the Census and administrative sources, we estimate family incomes for the vast major of plausible applicants from the U.S. We find that the Initiative had a significant effect almost entirely because it attracted a pool of applicants that was larger and slightly poorer. It appears that very similar standards of admission were used for this group as had been used in previous years. This group, once admitted, enrolled at a rate very similar to that of previous years. Thus, there are a greater number of low income students in the Class of 2009 than in the Class of 2008 simply because more well-qualified, low income students applied. Many apparently qualified students still do not apply, and many of these "missing applicants" come from high schools that have little or no tradition of sending applications to selective private colleges. Targeted outreach to such "one offs" -- that is, students who are one of only a few qualified students from their school in recent years -- may be a way for selective private colleges to increase their income diversity.
The utility of MODIS-sPRI for investigating the photosynthetic light-use efficiency in a Mediterranean deciduous forest
The present study investigated the utility of Moderate Resolution Imaging Spectroradiometer (MODIS)-derived sPRI (scaled photochemical reflectance index) and its relationship to photosynthetic light-use efficiency (LUE) calculated from eddy covariance tower data. The analysis was performed over two consecutive years (2003â2004) in a Mediterranean Quercus cerris L. forest site in Italy. Temperature and rainfall conditions differed markedly over the study period, with 2003 being a notable drought year and 2004 a non-drought year. MODIS ocean bands 11 (centred at 531 nm) and 12 (centred at 551 nm) were used for calculating sPRI. LUE exhibited substantial variability within 2003 and 2004, and a moderate relationship between MODIS-sPRI and LUE was observed during the wet year, and for backscattering scenes. This demonstrated the capacity of sPRI to detect xanthophyll cycle activation by vegetation during high light conditions. However, our results show that sPRI should be used with care, particularly under severe water stress conditions, when an increased influence of confounding factors, such canopy structure, illumination, and viewing angles, is observed
Inert Drying System for Copper Paste Application in PV
AbstractIn this study we show that the electrical characteristics of low temperature polymer pastes are improved by carrying out the curing process in an inert nitrogen atmosphere. In order to reduce the solar cell production costs, numerous scientific works are devoted to the question, whether the commonly used silver paste can be replaced by a copper based paste. However, a major problem with the latter is, that copper tends to oxidate during the thermal treatment. Hence, this work focuses on the development of an inert inline drying system to avoid the oxidation of copper based polymer pastes. For reference, silver based polymer pastes are investigated simultaneously. Therefore the influence of different nitrogen curing atmospheres on the electrical resistance and the weight loss of the pastes is evaluated. The electrical resistance of both silver and copper based pastes is improved by reducing the residual oxygen concentration. To investigate the reason for this, the samples are analyzed by micrographics. Furthermore it is shown, that the weight loss of the pastes shows no dependence on the curing atmosphere
Angiopoietin-like 4 based therapeutics for proteinuria and kidney disease
Current drugs used to treat proteinuric disorders of the kidney have been borrowed from other branches of medicine, and are only partially effective. The discovery of a central, mechanistic role played by two different forms of the secreted glycoprotein angiopoietin-like 4 (Angptl4) in human and experimental glomerular disease has opened new treatment avenues. Localized upregulation of a hyposialylated form (lacks sialic acid residues) of Angptl4 secreted by podocytes induces the cardinal morphological and clinical manifestations of human minimal change disease, and is also being increasingly recognized as a significant contributor toward proteinuria in experimental diabetic nephropathy. Oral treatment with low doses of N-acetyl-D-mannosamine, a naturally occurring precursor of sialic acid, improves sialylation of Angptl4 in vivo, and reduces proteinuria by over 40%. By contrast, a sialylated circulating form of Angptl4, mostly secreted from skeletal muscle, heart and adipose tissue in all major primary glomerular diseases, reduces proteinuria while also causing hypertriglyceridemia. Intravenous administration of recombinant human Angptl4 mutated to avoid hypertriglyceridemia and cleavage has remarkable efficacy in reducing proteinuria by as much as 65% for 2 weeks after a single low dose. Both interventions are mechanistically relevant, utilize naturally occurring pathways, and represent new generation therapeutic agents for chronic kidney disease related to glomerular disorders
Power Participation in Digital Citizen Engagement in South African Local Government: The Case of MobiSAM
open access bookA lack of service delivery and accountability are two characteristic challenges of numerous municipalities (local government) in South Africa. MobiSAM was introduced as a collaborative effort between a local university, civil society, residents, and local government to grow digital citizen engagement, facilitate two-way communication between local government and its citizenry, and contribute to the improved provision of basic services. Through the course of the project, it became clear that power, with respect to knowledge, was at play in the interactions or lack thereof between local government and citizens. This work-in-progress paper begins the journey of exploration of the power/knowledge dynamics at play in the MobiSAM project (using the SECI model and the Power Cube) by unpacking and understanding the nature of knowledge processed in the project and the associated knowledge creation processes that ensued between the different project stakeholders over time. The influence of power in determining the effective transfer of knowledge between key stakeholders of the project, for capacity building and organisational learning has emerged as an important issue in need of thorough investigation and critical analysis. This work in progress paper presents the preliminary framing of the research findings on the phases associated with the interplay of knowledge and power in the MobiSAM project, which are: 1) Realisation, 2) Navigating Responsiveness, and 3) Emergence
Daring to be differential : metabarcoding analysis of soil and plant-related microbial communities using amplicon sequence variants and operational taxonomical units
Background: Microorganisms are not only indispensable to ecosystem functioning, they are also keystones for emerging technologies. In the last 15âyears, the number of studies on environmental microbial communities has increased exponentially due to advances in sequencing technologies, but the large amount of data generated remains difficult to analyze and interpret. Recently, metabarcoding analysis has shifted from clustering reads using Operational Taxonomical Units (OTUs) to Amplicon Sequence Variants (ASVs). Differences between these methods can seriously affect the biological interpretation of metabarcoding data, especially in ecosystems with high microbial diversity, as the methods are benchmarked based on low diversity datasets.
Results: In this work we have thoroughly examined the differences in community diversity, structure, and complexity between the OTU and ASV methods. We have examined culture-based mock and simulated datasets as well as soil- and plant-associated bacterial and fungal environmental communities. Four key findings were revealed. First, analysis of microbial datasets at family level guaranteed both consistency and adequate coverage when using either method. Second, the performance of both methods used are related to community diversity and sample sequencing depth. Third, differences in the method used affected sample diversity and number of detected differentially abundant families upon treatment; this may lead researchers to draw different biological conclusions. Fourth, the observed differences can mostly be attributed to low abundant (relative abundance <â0.1%) families, thus extra care is recommended when studying rare species using metabarcoding. The ASV method used outperformed the adopted OTU method concerning community diversity, especially for fungus-related sequences, but only when the sequencing depth was sufficient to capture the community complexity.
Conclusions: Investigation of metabarcoding data should be done with care. Correct biological interpretation depends on several factors, including in-depth sequencing of the samples, choice of the most appropriate filtering strategy for the specific research goal, and use of family level for data clustering
Interventions to increase access to or uptake of physical health screening in people with severe mental illness: a realist review
Objectives: To identify and evaluate interventions aimed at increasing uptake of, or access to, physical health screening by adults with severe mental illness; to examine why interventions might work.
Design: Realist review.
Setting: Primary, secondary and tertiary care.
Results: A systematic search identified 1448 studies, of which 22 met the inclusion criteria. Studies were from Australia (n=3), Canada (n=1), Hong Kong (n=1), UK (n=11) and USA (n=6). The studies focused on breast cancer screening, infection preventive services and metabolic syndrome (MS) screening by targeting MSrelated risk factors. The interventions could be divided into those focusing on (1) health service delivery changes (12 studies), using quality improvement, randomised controlled trial, cluster randomised feasibility trial, retrospective audit, cross-sectional study and satisfaction survey designs and (2) tests of tools designed to facilitate screening (10 studies) using consecutive case series, quality improvement, retrospective evaluation and preâpost audit study designs. All studies reported improved uptake of screening, or that patients had received screening they would not have had without the intervention. No estimation of overall effect size was possible due to heterogeneity in study design and quality. The following factors may contribute to intervention success: staff and stakeholder involvement in screening, staff flexibility when taking physical measurements (eg, using adapted equipment), strong links with primary care and having a pharmacist on the ward.
Conclusions: A range of interventions may be effective, but better quality research is needed to determine any effect size. Researchers should consider how interventions may work when designing and testing them in order to target better the specific needs of this population in the most appropriate setting. Behaviour-change interventions to reduce identified barriers of patient and health professional resistance to screening this population are required. Resource constraints, clarity over professional roles and better coordination with primary care need to be addresse
Plasmodium falciparum Produce Lower Infection Intensities in Local versus Foreign Anopheles gambiae Populations
Both Plasmodium falciparum and Anopheles gambiae show great diversity in Africa, in their own genetic makeup and population dynamics. The genetics of the individual mosquito and parasite are known to play a role in determining the outcome of infection in the vector, but whether differences in infection phenotype vary between populations remains to be investigated. Here we established two A. gambiae s.s. M molecular form colonies from Cameroon and Burkina Faso, representing a local and a foreign population for each of the geographical sites. Experimental infections of both colonies were conducted in Cameroon and Burkina Faso using local wild P. falciparum, giving a sympatric and allopatric vector-parasite combination in each site. Infection phenotype was determined in terms of oocyst prevalence and intensity for at least nine infections for each vector-parasite combination. Sympatric infections were found to produce 25% fewer oocysts per midgut than allopatric infections, while prevalence was not affected by local/foreign interactions. The reduction in oocyst numbers in sympatric couples may be the result of evolutionary processes where the mosquito populations have locally adapted to their parasite populations. Future research on vector-parasite interactions must take into account the geographic scale of adaptation revealed here by conducting experiments in natural sympatric populations to give epidemiologically meaningful results
Functional characterization of Arabidopsis ARGONAUTE 3 in reproductive tissues
Arabidopsis encodes ten ARGONAUTE (AGO) effectors of RNA silencing, canonically loaded with either 21â22 nucleotide (nt) long small RNAs (sRNA) to mediate postâtranscriptionalâgeneâsilencing (PTGS) or 24nt sRNAs to promote RNAâdirectedâDNAâmethylation. Using fullâlocus constructs, we characterized the expression, biochemical properties, and possible modes of action of AGO3. Although AGO3 arose from a recent duplication at the AGO2 locus, their expression patterns differ drastically, with AGO2 being expressed in both male and female gametes whereas AGO3 accumulates in aerial vascular terminations and specifically in chalazal seed integuments. Accordingly, AGO3 downâregulation alters gene expression in siliques. Similar to AGO2, AGO3 binds sRNAs with a strong 5ââadenosine bias, but unlike Arabidopsis AGO2, it binds most efficiently 24nt sRNAs. AGO3 immunoprecipitation experiments in siliques revealed that these sRNAs mostly correspond to genes and intergenic regions in a manner reflecting their respective accumulation from their lociâofâorigin. AGO3 localizes to the cytoplasm and coâfractionates with polysomes to possibly mediate PTGS via translation inhibition
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