Research Findings: Universal screening is the first stage in identifying students at risk for reading difficulties within a Response to Intervention model. However, there is a lack of validated ...screening tools for assessing reading abilities in first-grade students from Spain. This pilot study examines the technical adequacy, classification accuracy, and best predictors within a set of curriculum-based measures (CBMs) in Spanish. A sample of 178 first graders from urban and peripheral areas of Santa Cruz de Tenerife (the Canary Islands, Spain) was assessed in the fall, winter, and spring. Receiver operating characteristic curves and logistic regression models were conducted to evaluate the predictive validity of each CBM and their composite score. In addition, students' learning growth on each CBM was analyzed using hierarchical linear models. Although results suggested that most of the CBMs had adequate reliability and validity throughout first grade and were able to detect students' growth, some measures showed low reliability and validity coefficients. Practice or Policy: Some of the studied CBMs could potentially be used as universal screening to early detect reading difficulties in this population. A two-stage gated screening procedure is proposed for future research and practical implementation using oral reading fluency in the first step.
Rights‐based fisheries management (RBFM) seeks to create market incentives to reduce competition, avoid overexploitation, and increase economic efficiency. Particularly for artisanal fisheries, ...however, assumptions of RBFM may not be met and its use needs to be carefully considered. This study applies an existing tool (SEASALT) to evaluate the strength of RBFM based on attributes of security, exclusivity, fish mortality, scale, responsibility, limitations, and transferability. Results for 17 fisheries in Mexico show a positive (nonsignificant) relationship between the strength of RBFM and stock status, and no effect on prices or landed value. Real‐world fisheries governance systems are much more complex than the simple linkages between attributes implied in SEASALT, but results highlight pre‐existing monitoring and enforcement capacity as essential for successful RBFM. Transitions to RBFM may strengthen this capacity, but likely cannot create it where it does not already exist. Based on our findings, RBFM strategies may benefit from group quotas with limited transferability to avoid negative social outcomes from consolidation or rent capture by intermediaries; this could potentially build on the latent capacity of traditional community associations common in many artisanal fisheries.
The Colombian Creole bovine breeds Blanco Orejinegro (BON) and Sanmartinero (SM) are the most important of the Creole breeds in Colombia because they are the most numerous, the most widely used in ...their pure form or in crosses with foreign breeds, and because they are dual-purpose producers of milk and meat. We estimated heritability for adaptability (coefficient of adaptability-CA and heat tolerance coefficient-HTC), and reproductive traits (age at first calving-AFC and calving interval-CI) using genomic and genealogical records. Variance components were estimated using the AIREMLF90 program under a mixed single-trait model to calculate genealogical and genomic heritability, based on genealogical, phenotypic, and genomic information. Genomic information was obtained for 1,262 BON and 742 SM genotyped animals, with a total of 58,868 single nucleotide polymorphisms-SNPs in BON, and 57,482 SNPs in SM. Genealogical heritability values in BON for CA and HTC were 0.05 and 0.13, and 0.06 and 0.13 for AFC and CI, respectively. For the SM breed, genealogical heritability values for CA and HTC were 0.08 and 0.09, and 0.20 and 0.07 for AFC and CI, respectively. Genomic heritability values in the BON breed for CA and HTC were 0.06 and 0.16, and 0.07 and 0.14 for AFC and CI, respectively. For the SM breed, genomic heritability values for CA and HTC were 0.10 and 0.11, and 0.20 and 0.07 for AFC and CI, respectively. Heritabilities for adaptability traits in both BON and SM were of medium to low magnitude, indicating the possibility of using these variables in selection schemes for adaptation-related characteristics.
The main objective of this study was to examine the effectiveness of an intervention implemented by elementary school teachers within the context of the Response to Intervention (RtI) model. For this ...purpose, a Tier 2 or secondary intervention was implemented by Spanish-speaking teachers in grades K-3 after receiving training to implement RtI components with fidelity. A total of 1,923 at-risk students were assigned to treatment (in reading, n = 542; in math, n = 483) or control (in reading, n = 406; in math, n = 492). Teachers were provided with a support system that included two web-based training programs for reading (i.e., Letra program) and math (i.e., Primate program). Implementation fidelity was analyzed using direct observations and self-reports. All students were assessed three times during the academic year. A hierarchical linear growth modeling was conducted, and differences in the growth rate of reading and math performance were analyzed between at-risk students who have received the intervention and those who have not received it. Children at-risk in the intervention condition appeared to benefit more than at-risk children in the control condition. Moreover, findings indicate that the earlier the intervention, the greater the percentage of students who leave the situation of risk of learning difficulties in reading and math.
Redox flow cells for energy conversion Ponce de León, C.; Frías-Ferrer, A.; González-García, J. ...
Journal of power sources,
09/2006, Letnik:
160, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Energy storage technologies provide an alternative solution to the problem of balancing power generation and power consumption. Redox flow cells are designed to convert and store electrical energy ...into chemical energy and release it in a controlled fashion when required. Many redox couples and cell designs have being evaluated. In this paper, redox flow systems are compared in the light of characteristics such as open circuit potential, power density, energy efficiency and charge-discharge behaviour. The key advantages and disadvantages of redox flow cells are considered while areas for further research are highlighted.
Redox flow batteries (RFBs) have emerged as prime candidates for energy storage on the medium and large scales, particularly at the grid scale. The demand for versatile energy storage continues to ...increase as more electrical energy is generated from intermittent renewable sources. A major barrier in the way of broad deployment and deep market penetration is the use of expensive metals as the active species in the electrolytes. The use of organic redox couples in aqueous or non-aqueous electrolytes is a promising approach to reducing the overall cost in long-term, since these materials can be low-cost and abundant. The performance of such redox couples can be tuned by modifying their chemical structure. In recent years, significant developments in organic redox flow batteries has taken place, with the introduction of new groups of highly soluble organic molecules, capable of providing a cell voltage and charge capacity comparable to conventional metal-based systems. This review summarises the fundamental developments and characterization of organic redox flow batteries from both the chemistry and materials perspectives. The latest advances, future challenges and opportunities for further development are discussed.
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•Future opportunities for organic redox flow batteries are reviewed.•Advantages, disadvantages and challenges are discussed.•Organic redox couples are classified (aqueous & non-aqueous chemistries).•The performance of systems are discussed against benchmarks.•Critical areas requiring further R & D are highlighted.
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•The history and relevance of redox flow batteries in energy storage are highlighted.•Electrochemical engineering principles of cell design and operation are summarised.•Performance ...can be quantified at a known state of charge and modelled by multiphysics.•Reaction environment can be described by dimensionless relationships.•The importance of operational parameters is illustrated by experimental data.
Despite many studies and several extensive reviews of redox flow batteries (RFBs) over the last three decades, information on engineering aspects is scarce, which hinders progress with scale-up and implementation of this energy storage technology. This review summarises cell design requirements then critically considers design, construction and cell features together with their benefits and problems, leading to good practice through improved cell performance, knowledge and experience. Techniques for the characterisation of the reaction environment are illustrated by measurements of mass transport to (and from) electrode surfaces as a function of flow conditions, as well as pressure drop and electrolyte flow dispersion. The influence of design features on performance is illustrated by the effect of process conditions on the components of cell potential. Adequate attention to engineering aspects is seen to be critical to the effective performance of RFBs, particularly during scale-up and long-term operation. Techniques for the characterisation of reaction environment are summarised and a list of essential design and construction factors is provided. Finally, critical areas needing research and development are highlighted.
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