Class Size Reduction: A Facilitator of Instructional Program Coherence

This case study evaluation explored how class size reduction (CSR) combined with other reform initiatives and contextual factors to affect student achievement. The evaluand was an elementary school that implemented Wisconsin\u27s fortified CSR program named SAGE. Evidence was collected from existing records and purposively selected teachers via a focus group. A three-phase cut and paste analysis strategy was used to reduce data, display data, and draw and verify conclusions. Main and interaction effects are reported. Findings suggest smaller classes may affect student achievement by facilitating the coherence of school-level instructional programs

Atrial fibrillation: a study of substrate and triggers

1. Introduction2. History and Overview of Atrial Fibrillation3. A New Fully Implantable Goat Model of Atrial Fibrillation4. The Profibdilatory Action of Verapamil is Not Prevented by Propafenone5. Repetitive Four-Week Periods of Atrial Electrical Remodelling Promote Stability of Atrial Fibrillation -Evidence for a Second Factor Independent of Atrial Refractoriness in the Self-Perpetuation of Atrial Fibrillation6. Atrial Ectopy - The Coupling Interval of Atrial Premature Beats Following DC Cardioversion of Persistent AF Predicts Subsequent Recurrence of AF7. Atrial Ectopy -Evidence for Reversal of Atrial Electrical Remodelling8. Prevalence and Significance of Focal Sources of Atrial Arrhythmia in Patients Undergoing Cardioversion of Persistent Atrial Fibrillation9. Changes in Heart Rate Variability Following Cardioversion of Persistent Atrial Fibrillation in Ma

Examining the Cost-Outcome Relationship of a Fortified Class-Size Reduction Program

Class-size reduction initiatives have been criticized for producing modest achievement gains for the resources they consume. Wisconsin’s Student Achievement Guarantee in Education (SAGE) was designed to amplify the achievement benefits of smaller classes by requiring complementary changes in the teaching and learning environment and accountability for results. This study examined SAGE in an urban school district. The achievement benefits realized by the evaluand were marginalized by high per-student costs and similar performance of comparison groups on a state-mandated reading test. Suggestions for improving the cost-outcome relationship were presented

Optimization of ethylene bioproduction in Synechocystis sp. PCC 6803

Ethylene is the most widely produced petrochemical feedstock globally. It is currently produced exclusively from fossil fuels through petroleum fractionation, the largest CO₂-emitting process in the chemical industry. In this study, the efe gene encoding an ethylene-forming enzyme was expressed in Synechocystis sp. PCC 6803, leading to continuous ethylene production. By optimizing concentrations of key nutrients in the media of Synechocystis, we achieved a better understanding of the limiting nutrients that lead to optimal ethylene bioproduction. Using response surface methodology, we determined that major nutrients found in the standard Synechocystis media—NO₃⁺, PO₄³⁻, SO₄²⁻, Ca⁺, Mg⁺, and HCO₃⁻—are required for optimal growth, suggesting that ethylene production is strongly correlated with general growth

Reasons for littering: Social constructions from lower income communities in South Africa

Littering has been defined as the careless and improper disposal of small amounts of waste that results in unwanted and unnatural elements remaining in the environment. People tend to blame external factors for their own littering. A person seldom refers to themselves as being the litterer but will rather place the blame on insufficient infrastructure, such as lack of bins, or on other persons. When referring to other people, they identify problematic behaviour and personal traits such as ignorance, naivety, need for convenience, laziness and inattentiveness as causes of littering. This study addressed the gap in the literature on the socially constructed perceptions people hold about reasons for littering in the South African context, as subjectively perceived reasons for littering may correspond with actual causes and could point towards options for tackling the littering problem. Five lower socio-economic areas in South Africa – particularly those that experience major infrastructural challenges – were included in the study. Qualitative semistructured interviews were held with 322 residents from the respective areas. The data were thematically analysed and the results from the areas compared with each other. The cross-case analysis confirmed that littering is contingent on contextual effects, and unique reasons for littering in the South African context were mentioned. The research reported on in this study highlights that we have only thematically ‘identified’ or named the socially constructed perceptions about the reasons for littering by the participants. The importance of creating platforms and processes for dialogues to deepen our understanding of people’s socially constructed perceptions and subsequent behaviour, is of critical importance.Significance:• This study presents subjective or self-reported perceptions of people living in lower socio-economic areas on the reasons for littering and dumping.• These perceptions about reasons for littering then provide directions for possible interventions to manage and curb littering in the South African context

Determinants of Cost to Client in Accessing Rural Financial Services – A Case of Zambia's Chongwe District

Providing affordable access to appropriate financial services for the low-income population has been an on-going challenge for most developing nations, Zambia included. On this premise, this paper seeks to empirically investigate and quantify costs to clients in accessing financial services in the rural areas of Zambia, based on cross-sectional primary data collected in the Chongwe district from 236 households, documentation and key informant interviews. This study used the Probit and Heckman selection models to analyse cost to the client factors affecting the likelihood of accessing financial services (credit) by rural households in Zambia. Results revealed that households’ costs incurred by clients in accessing financial services are not limited to financial costs such interest, fees, transport and savings, etc., but equally other hidden costs such regulatory and compliance costs, economic costs, psychological costs, and social and cultural costs. The study recommends that policy formulation in the areas of financial inclusion, rural and agricultural finance should be based on reducing cost-to-client attributes such as the regulatory and compliance costs, economic costs and psychological costs identified above. Keywords: costs to client, financial services, access to finance, Heckman two-stage model

An improved optimization technique for estimation of solar photovoltaic parameters

The nonlinear current vs voltage (I-V) characteristics of solar PV make its modelling difficult. Optimization techniques are the best tool for identifying the parameters of nonlinear models. Even though, there are different optimization techniques used for parameter estimation of solar PV, still the best optimized results are not achieved to date. In this paper, Wind Driven Optimization (WDO) technique is proposed as the new method for identifying the parameters of solar PV. The accuracy and convergence time of the proposed method is compared with results of Pattern Search (PS), Genetic Algorithm (GA), and Simulated Annealing (SA) for single diode and double diode models of solar PV. Furthermore, for performance validation, the parameters obtained through WDO are compared with hybrid Bee Pollinator Flower Pollination Algorithm (BPFPA), Flower Pollination Algorithm (FPA), Generalized Oppositional Teaching Learning Based Optimization (GOTLBO), Artificial Bee Swarm Optimization (ABSO), and Harmony Search (HS). The obtained results clearly reveal that WDO algorithm can provide accurate optimized values with less number of iterations at different environmental conditions. Therefore, the WDO can be recommended as the best optimization algorithm for parameter estimation of solar PV

CRISPR/Cas9-induced (CTG⋅CAG)n repeat instability in the myotonic dystrophy type 1 locus: implications for therapeutic genome editing

Myotonic dystrophy type 1 (DM1) is caused by (CTG⋅CAG)n-repeat expansion within the DMPK gene and thought to be mediated by a toxic RNA gain of function. Current attempts to develop therapy for this disease mainly aim at destroying or blocking abnormal properties of mutant DMPK (CUG)n RNA. Here, we explored a DNA-directed strategy and demonstrate that single clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-cleavage in either its 5′ or 3′ unique flank promotes uncontrollable deletion of large segments from the expanded trinucleotide repeat, rather than formation of short indels usually seen after double-strand break repair. Complete and precise excision of the repeat tract from normal and large expanded DMPK alleles in myoblasts from unaffected individuals, DM1 patients, and a DM1 mouse model could be achieved at high frequency by dual CRISPR/Cas9-cleavage at either side of the (CTG⋅CAG)n sequence. Importantly, removal of the repeat appeared to have no detrimental effects on the expression of genes in the DM1 locus. Moreover, myogenic capacity, nucleocytoplasmic distribution, and abnormal RNP-binding behavior of transcripts from the edited DMPK gene were normalized. Dual sgRNA-guided excision of the (CTG⋅CAG)n tract by CRISPR/Cas9 technology is applicable for developing isogenic cell lines for research and may provide new therapeutic opportunities for patients with DM1

Host tissue proteomics reveal insights into the molecular basis of Schistosoma haematobium-induced bladder pathology.

Urogenital schistosomiasis remains a major public health concern worldwide. In response to egg deposition, the host bladder undergoes gross and molecular morphological changes relevant for disease manifestation. However, limited mechanistic studies to date imply that the molecular mechanisms underlying pathology are not well-defined. We leveraged a mouse model of urogenital schistosomiasis to perform for the first time, proteome profiling of the early molecular events that occur in the bladder after exposure to S. haematobium eggs, and to elucidate the protein pathways involved in urogenital schistosomiasis-induced pathology. Purified S. haematobium eggs or control vehicle were microinjected into the bladder walls of mice. Mice were sacrificed seven days post-injection and bladder proteins isolated and processed for proteome profiling using mass spectrometry. We demonstrate that biological processes including carcinogenesis, immune and inflammatory responses, increased protein translation or turnover, oxidative stress responses, reduced cell adhesion and epithelial barrier integrity, and increased glucose metabolism were significantly enriched in S. haematobium infection. S. haematobium egg deposition in the bladder results in significant changes in proteins and pathways that play a role in pathology. Our findings highlight the potential bladder protein indicators for host-parasite interplay and provide new insights into the complex dynamics of pathology and characteristic bladder tissue changes in urogenital schistosomiasis. The findings will be relevant for development of improved interventions for disease control

Comparison of chemical compounds associated with sclerites from healthy and diseased sea fan corals (Gorgonia ventalina)

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PeerJ 5 (2017): e3677, doi:10.7717/peerj.3677.The roles of gorgonian sclerites as structural components and predator deterrents have been widely studied. Yet their role as barriers against microbes has only recently been investigated, and even less is known about the diversity and roles of the chemical compounds associated with sclerites. Here, we examine the semi-volatile organic compound fraction (SVOCs) associated with sclerites from healthy and diseased Gorgonia ventalina sea fan corals to understand their possible role as a stress response or in defense of infection. We also measured the oxidative potential of compounds from diseased and healthy G. ventalina colonies. The results showed that sclerites harbor a great diversity of SVOCs. Overall, 70 compounds were identified, the majority of which are novel with unknown biological roles. The majority of SVOCs identified exhibit multiple immune-related roles including antimicrobial and radical scavenging functions. The free radical activity assays further confirmed the anti-oxidative potential of some these compounds. The anti-oxidative activity was, nonetheless, similar across sclerites regardless of the health condition of the colony, although sclerites from diseased sea fans display slightly higher anti-oxidative activity than the healthy ones. Sclerites harbor great SVOCs diversity, the majority of which are novel to sea fans or any other corals. Yet the scientific literature consulted showed that the roles of compounds found in sclerites vary from antioxidant to antimicrobial compounds. However, this study fell short in determine the origin of the SVOCs identified, undermining our capacity to determine the biological roles of the SVOCs on sclerites and sea fans.This work was supported by the Puerto Rico Center for Environmental Neuroscience (PRCEN) through an NSF Centers of Research Excellent in Science and Technology (CREST) award, number HRD-1137725