833 resultados para Strategies Used To Learn


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The neutral bis ((pivaloyloxy)methyl) (PIV$\sb2\rbrack$ derivatives of FdUMP, ddUMP, and AZTMP were synthesized as potential membrane-permeable prodrugs of FdUMP, ddUMP, and AZTMP. These compounds were designed to enter cells by passive diffusion and revert to the parent nucleotides after removal of the PIV groups by hydrolytic enzymes. These prodrugs were prepared by condensation of FUdR, ddU, and AZT with PIV$\sb2$ phosphate in the presence of triphenylphosphine and diethyl azodicarboxylate (the Mitsunobo reagent). PIV$\sb2$-FdUMP, PIV$\sb2$-ddUMP, and PIV$\sb2$-AZTMP were stable in the pH range 1.0-4.0 (t$\sb{1/2} = {>}$100 h). They were also fairly stable at pH 7.4 (t$\sb{1/2} = {>}$40 h). In 0.05 M NaOH solution, however, they were rapidly degraded (t$\sb{1/2} < 2$ min). In the presence hog liver carboxylate esterase, they were converted quantitatively to the corresponding phosphodiesters, PIV$\sb1$-FdUMP, PIV$\sb1$-ddUMP, and PIV$\sb1$-AZTMP; after 24 h incubation, only trace amounts of FdUMP, ddUMP, and AZTMP (1-5%) were observed indicating that the PIV$\sb1$ compounds were poor substrates for the enzyme. In human plasma, the PIV$\sb2$ compounds were rapidly degraded with half-lives of less than 5 min. The rate of degradation of the PIV$\sb2$ compounds in the presence of phosphodiesterase I was the same as that in buffer controls, indicating that they were not substrates for this enzyme. In the presence of phosphodiesterase I, PIV$\sb1$-FdUMP, PIV$\sb1$-ddUMP, and PIV$\sb1$-AZTMP were converted quantitatively to FdUMP, ddUMP, and AZTMP.^ PIV$\sb2$-ddUMP and PIV$\sb2$-AZTMP were effective at controlling HIV type 1 infection in MT-4 and CEM tk$\sp-$ cells in culture. Mechanistic studies demonstrated that PIV$\sb2$-ddUMP and PIV$\sb2$-AZTMP were taken up by the cells and converted to ddUTP and AZTTP, both potent inhibitors of HIV reverse transcriptase. However, a potential shortcoming of PIV$\sb2$-ddUMP and PIV$\sb2$-AZTMP as clinical therapeutic agents is that they are rapidly degraded (t$\sb{1/2}$ = approx. 4 minutes) in human plasma by carboxylate esterases. To circumvent this limitation, chemically-labile nucleotide prodrugs and liposome-encapsulated nucleotide prodrugs were investigated. In the former approach, the protective groups bis(N, N-(dimethyl)carbamoyloxymethyl) (DM$\sb2$) and bis (N-(piperidino)carbamoyloxymethyl) (DP$\sb2$) were used to synthesize DM$\sb2$-ddUMP and DP$\sb2$-ddUMP, respectively. In aqueous buffers (pH range 1.0-9.0) these compounds were degraded with half-lives of 3 to 4 h. They had similar half-lives in human plasma demonstrating that they were resistant to esterase-mediated cleavage. However, neither compound gave rise to significant concentrations of ddUMP in CEM or CEM tk$\sp-$ cells. In the liposome-encapsulated nucleotide prodrug approach, three different liposomal formulations of PIV$\sb2$-ddUMP (L-PIV$\sb2$-ddUMP) were investigated. The half-lifes of these L-PIV$\sb2$-ddUMP preparations in human plasma were 2 h compared with 4 min for the free drug. The preparations were more effective at controlling HIV-1 infection than free PIV$\sb2$-ddUMP in human T cells in culture. Collectively, these data indicate that PIV$\sb2$-FdUMP, PIV$\sb2$-ddUMP, and PIV$\sb2$-AZTMP are effective membrane-permeable prodrugs of FdUMP, ddUMP, and AZTMP. ^

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The main aim of the methodology presented in this paper is to provide a framework for a participatory process for the appraisal and selection of options to mitigate desertification and land degradation. This methodology is being developed within the EU project DESIRE (www.desire-project.eu/) in collaboration with WOCAT (www.wocat.org). It is used to select promising conservation strategies for test-implementation in each of the 16 degradation and desertification hotspot sites in the Mediterranean and around the world. The methodology consists of three main parts: In a first step, prevention and mitigation strategies already applied at the respective DESIRE study site are identified and listed during a workshop with representatives of different stakeholders groups (land users, policy makers, researchers). The participatory and process-oriented approach initiates a mutual learning process among the different stakeholders by sharing knowledge and jointly reflecting on current problems and solutions related to land degradation and desertification. In the second step these identified, locally applied solutions (technologies and approaches) are assessed with the help of the WOCAT methodology. Comprehensive questionnaires and a database system have been developed to document and evaluate all relevant aspects of technical measures as well as implementation approaches by teams of researchers and specialists, together with land users. This research process ensures systematic assessing and piecing together of local information, together with specific details about the environmental and socio-economic setting. The third part consists of another stakeholder workshop where promising strategies for sustainable land management in the given context are selected, based on the best practices database of WOCAT, including the evaluated locally applied strategies at the DESIRE sites. These promising strategies will be assessed with the help of a selection and decision support tool and adapted for test-implementation at the study site.

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The Astronomical Institute of the University of Bern (AIUB) is conducting several search campaigns for space debris using optical sensors. The debris objects are discovered during systematic survey observations. In general, the result of a discovery consists in only a short observation arc, or tracklet, which is used to perform a first orbit determination in order to be able to observe t he object again in subsequent follow-up observations. The additional observations are used in the orbit improvement process to obtain accurate orbits to be included in a catalogue. In order to obtain the most accurate orbit within the time available it is necessary to optimize the follow-up observations strategy. In this paper an in‐depth study, using simulations and covariance analysis, is performed to identify the optimal sequence of follow-up observations to obtain the most accurate orbit propagation to be used for the space debris catalogue maintenance. The main factors that determine the accuracy of the results of an orbit determination/improvement process are: tracklet length, number of observations, type of orbit, astrometric error of the measurements, time interval between tracklets, and the relative position of the object along its orbit with respect to the observing station. The main aim of the covariance analysis is to optimize the follow-up strategy as a function of the object-observer geometry, the interval between follow-up observations and the shape of the orbit. This an alysis can be applied to every orbital regime but particular attention was dedicated to geostationary, Molniya, and geostationary transfer orbits. Finally the case with more than two follow-up observations and the influence of a second observing station are also analyzed.

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The north-eastern escarpment of Madagascar contains the island’s last remaining large-scale humid forest massifs surrounded by diverse small-scale agricultural mosaics. There is high deforestation mainly caused by shifting cultivation practiced by local land users to produce upland rice for subsistence. Today, large protected areas restrict land users’ access to forests to collect wood and other forest products. Moreover, they are no more able to expand their cultivated land, which leads to shorter shifting cultivation cycles and decreasing plot sizes for irrigated rice and cash crop cultivation. Cash crop production of clove and vanilla is exposed to risks such as extreme inter-annual price fluctuations, pests and cyclones. In the absence of work opportunities, agricultural extension services and micro-finance schemes people are stuck in a poverty trap. New development strategies are needed to mitigate the trade-offs between forest conservation and human well-being. As landscape composition and livelihood strategies vary across the region, these strategies need to be spatially differentiated to avoid implementing generic solutions, which do not fit the local context. However, up to date, little is known about the spatial patterns of shifting cultivation and other land use systems at the regional level. This is mainly due to the high spatial and temporal dynamics inherent to shifting cultivation, which makes it difficult to monitor the dynamics of this land use system with remote sensing methods. Furthermore, knowledge about land users’ livelihood strategies and the risks and opportunities they face stems from very few local case studies. To overcome this challenge, firstly, we used remote sensing data and a landscape mosaic approach to delineate the main landscape types at the regional level. Secondly, we developed a land user typology based on socio-ecological data from household surveys in 45 villages spread throughout the region. Combining the land user typology with the landscape mosaic map allowed us to reveal spatial patterns of the interaction between landscapes and people and to better understand the trade-offs between forest conservation and local wellbeing. While shifting cultivation systems are being transformed into more intensive permanent agricultural systems in many countries around the globe, Madagascar seems to be an exception to this trend. Linking land cover information to human-environmental interactions over large areas is crucial to designing policies and to inform decision making for a more sustainable development of this resource-rich but poverty-prone context.

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Soil indicators may be used for assessing both land suitability for restoration and the effectiveness of restoration strategies in restoring ecosystem functioning and services. In this review paper, several soil indicators, which can be used to assess the effectiveness of ecological restoration strategies in dryland ecosystems at different spatial and temporal scales, are discussed. The selected indicators represent the different viewpoints of pedology, ecology, hydrology, and land management. Two overall outcomes stem from the review. (i) The success of restoration projects relies on a proper understanding of their ecology, namely the relationships between soil, plants, hydrology, climate, and land management at different scales, which are particularly complex due to the heterogeneous pattern of ecosystems functioning in drylands. (ii) The selection of the most suitable soil indicators follows a clear identification of the different and sometimes competing ecosystem services that the project is aimed at restoring.

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This dissertation focuses on Project HOPE, an American medical aid agency, and its work in Tunisia. More specifically this is a study of the implementation strategies of those HOPE sponsored projects and programs designed to solve the problems of high morbidity and infant mortality rates due to environmentally related diarrheal and enteric diseases. Several environmental health programs and projects developed in cooperation with Tunisian counterparts are described and analyzed. These include (1) a paramedical manpower training program; (2) a national hospital sanitation and infection control program; (3) a community sewage disposal project; (4) a well reconstruction project; and (5) a solid-waste disposal project for a hospital.^ After independence, Tunisia, like many developing countries, encountered several difficulties which hindered progress toward solving basic environmental health problems and prompted a request for aid. This study discusses the need for all who work in development programs to recognize and assess those difficulties or constraints which affect the program planning process, including those latent cultural and political constraints which not only exist within the host country but within the aid agency as well. For example, failure to recognize cultural differences may adversely affect the attitudes of the host staff towards their work and towards the aid agency and its task. These factors, therefore, play a significant role in influencing program development decisions and must be taken into account in order to maximize the probability of successful outcomes.^ In 1969 Project HOPE was asked by the Tunisian government to assist the Ministry of Health in solving its health manpower problems. HOPE responded with several programs, one of which concerned the training of public health nurses, sanitary technicians, and aids at Tunisia's school of public health in Nabeul. The outcome of that program as well as the strategies used in its development are analyzed. Also, certain questions are addressed such as, what should the indicators of success be, and when is the time right to phase out?^ Another HOPE program analyzed involved hospital sanitation and infection control. Certain generic aspects of basic hospital sanitation procedures were documented and presented in the form of a process model which was later used as a "microplan" in setting up similar programs in other Tunisian hospitals. In this study the details of the "microplan" are discussed. The development of a nation-wide program without any further need of external assistance illustrated the success of HOPE's implementation strategies.^ Finally, although it is known that the high incidence of enteric disease in developing countries is due to poor environmental sanitation and poor hygiene practices, efforts by aid agencies to correct these conditions have often resulted in failure. Project HOPE's strategy was to maximize limited resources by using a systems approach to program development and by becoming actively involved in the design and implementation of environmental health projects utilizing "appropriate" technology. Three innovative projects and their implementation strategies (including technical specifications) are described.^ It is advocated that if aid agencies are to make any progress in helping developing countries basic sanitation problems, they must take an interdisciplinary approach to progrm development and play an active role in helping counterparts seek and identify appropriate technologies which are socially and economically acceptable. ^

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La agricultura es uno de los sectores más afectados por el cambio climático. A pesar de haber demostrado a lo largo de la historia una gran capacidad para adaptarse a nuevas situaciones, hoy en día la agricultura se enfrenta a nuevos retos tales como satisfacer un elevado crecimiento en la demanda de alimentos, desarrollar una agricultura sostenible con el medio ambiente y reducir las emisiones de gases de efecto invernadero. El potencial de adaptación debe ser definido en un contexto que incluya el comportamiento humano, ya que éste juega un papel decisivo en la implementación final de las medidas. Por este motivo, y para desarrollar correctamente políticas que busquen influir en el comportamiento de los agricultores para fomentar la adaptación a estas nuevas condiciones, es necesario entender previamente los procesos de toma de decisiones a nivel individual o de explotación, así como los efectos de los factores que determinan las barreras o motivaciones de la implementación de medidas. Esta Tesis doctoral trata de profundizar en el análisis de factores que influyen en la toma de decisiones de los agricultores para adoptar estrategias de adaptación al cambio climático. Este trabajo revisa la literatura actual y desarrolla un marco metodológico a nivel local y regional. Dos casos de estudio a nivel local (Doñana, España y Makueni, Kenia) han sido llevados a cabo con el fin de explorar el comportamiento de los agricultores hacia la adaptación. Estos casos de estudio representan regiones con notables diferencias en climatología, impactos del cambio climático, barreras para la adaptación y niveles de desarrollo e influencia de las instituciones públicas y privadas en la agricultura. Mientras el caso de estudio de Doñana representa un ejemplo de problemas asociados al uso y escasez del agua donde se espera que se agraven en el futuro, el caso de estudio de Makueni ejemplifica una zona fuertemente amenazada por las predicciones de cambio climático, donde adicionalmente la falta de infraestructura y la tecnología juegan un papel crucial para la implementación de la adaptación. El caso de estudio a nivel regional trata de generalizar en África el comportamiento de los agricultores sobre la implementación de medidas. El marco metodológico que se ha seguido en este trabajo abarca una amplia gama de enfoques y métodos para la recolección y análisis de datos. Los métodos utilizados para la toma de datos incluyen la implementación de encuestas, entrevistas, talleres con grupos de interés, grupos focales de discusión, revisión de estudios previos y bases de datos públicas. Los métodos analíticos incluyen métodos estadísticos, análisis multi‐criterio para la toma de decisiones, modelos de optimización de uso del suelo y un índice compuesto calculado a través de indicadores. Los métodos estadísticos se han utilizado con el fin de evaluar la influencia de los factores socio‐económicos y psicológicos sobre la adopción de medidas de adaptación. Dentro de estos métodos se incluyen regresiones logísticas, análisis de componentes principales y modelos de ecuaciones estructurales. Mientras que el análisis multi‐criterio se ha utilizado con el fin de evaluar las opciones de adaptación de acuerdo a las opiniones de las diferentes partes interesadas, el modelo de optimización ha tenido como fin analizar la combinación óptima de medidas de adaptación. El índice compuesto se ha utilizado para evaluar a nivel regional la implementación de medidas de adaptación en África. En general, los resultados del estudio ponen de relieve la gran importancia de considerar diferentes escalas espaciales a la hora de evaluar la implementación de medidas de adaptación al cambio climático. El comportamiento de los agricultores es diferente entre lugares considerados a una escala local relativamente pequeña, por lo que la generalización de los patrones del comportamiento a escalas regionales o globales resulta relativamente compleja. Los resultados obtenidos han permitido identificar factores determinantes tanto socioeconómicos como psicológicos y calcular su efecto sobre la adopción de medidas de adaptación. Además han proporcionado una mejor comprensión del distinto papel que desempeñan los cinco tipos de capital (natural, físico, financiero, social y humano) en la implementación de estrategias de adaptación. Con este trabajo se proporciona información de gran interés en los procesos de desarrollo de políticas destinadas a mejorar el apoyo de la sociedad a tomar medidas contra el cambio climático. Por último, en el análisis a nivel regional se desarrolla un índice compuesto que muestra la probabilidad de adoptar medidas de adaptación en las regiones de África y se analizan las causas que determinan dicha probabilidad de adopción de medidas. ABSTRACT Agriculture is and will continue to be one of the sectors most affected by climate change. Despite having demonstrated throughout history a great ability to adapt, agriculture today faces new challenges such as meeting growing food demands, developing sustainable agriculture and reducing greenhouse gas emissions. Adaptation policies planned on global, regional or local scales are ultimately implemented in decision‐making processes at the farm or individual level so adaptation potentials have to be set within the context of individual behaviour and regional institutions. Policy instruments can play a formative role in the adoption of such policies by addressing incentives/disincentives that influence farmer’s behaviour. Hence understanding farm‐level decision‐making processes and the influence of determinants of adoption is crucial when designing policies aimed at fostering adoption. This thesis seeks to analyse the factors that influence decision‐making by farmers in relation to the uptake of adaptation options. This work reviews the current knowledge and develops a methodological framework at local and regional level. Whilst the case studies at the local level are conducted with the purpose of exploring farmer’s behaviour towards adaptation the case study at the regional level attempts to up‐scale and generalise theory on adoption of farmlevel adaptation options. The two case studies at the local level (Doñana, Spain and Makueni, Kenya) encompass areas with different; climates, impacts of climate change, adaptation constraints and limits, levels of development, institutional support for agriculture and influence from public and private institutions. Whilst the Doñana Case Study represents an area plagued with water‐usage issues, set to be aggravated further by climate change, Makueni Case study exemplifies an area decidedly threatened by climate change where a lack of infrastructure and technology plays a crucial role in the uptake of adaptation options. The proposed framework is based on a wide range of approaches for collecting and analysing data. The approaches used for data collection include the implementation of surveys, interviews, stakeholder workshops, focus group discussions, a review of previous case studies, and public databases. The analytical methods include statistical approaches, multi criteria analysis for decision‐making, land use optimisation models, and a composite index based on public databases. Statistical approaches are used to assess the influence of socio‐economic and psychological factors on the adoption or support for adaptation measures. The statistical approaches used are logistic regressions, principal component analysis and structural equation modelling. Whilst a multi criteria analysis approach is used to evaluate adaptation options according to the different perspectives of stakeholders, the optimisation model analyses the optimal combination of adaptation options. The composite index is developed to assess adoption of adaptation measures in Africa. Overall, the results of the study highlight the importance of considering various scales when assessing adoption of adaptation measures to climate change. As farmer’s behaviour varies at a local scale there is elevated complexity when generalising behavioural patterns for farmers at regional or global scales. The results identify and estimate the effect of most relevant socioeconomic and psychological factors that influence adoption of adaptation measures to climate change. They also provide a better understanding of the role of the five types of capital (natural, physical, financial, social, and human) on the uptake of farm‐level adaptation options. These assessments of determinants help to explain adoption of climate change measures and provide helpful information in order to design polices aimed at enhancing societal support for adaptation policies. Finally the analysis at the regional level develops a composite index which suggests the likelihood of the regions in Africa to adopt farm‐level adaptation measures and analyses the main causes of this likelihood of adoption.

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Microencapsulation of cell spheroids in an immunoselective, highly biocompatible, biomembrane offers a way to create viable implantation options in the treatment of insulin-dependent diabetes mellitus (IDDM). Traditionally the encapsulation process has been achieved through the injection/extrusion of alginate/cell mixtures into a calcium chloride solution to produce calcium alginate capsules around the cells. A novel alternative is explored here through a procedure using an emulsion process to produce thin adherent calcium alginate membranes around cell spheroids. In this study, a thorough investigation has been used to establish the emulsion process parameters that are critical to the formation of a coherent alginate coat both on a model spheroid system and subsequently on cell spheroids. Optical and fluorescence microscopy are used to assess the morphology and coherence of the calcium alginate/ poly-L-ornithine/alginate (APA) capsules produced. (c) 2005 Wiley Periodicals, Inc.

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The communicative practice in the ex-GDR was complex and diverse, although public political discourse had been fairly ritualized. Text-types characteristic of the Communist Party discourse were full of general (superordinate) terms semantic specification was hardly possible (propositional reduction). Changes in the social world result in changes in the communicative practice as well. However, a systematic comparision of text-types across cultures and across ideological boundaries reveals both differences in the textual macro- and superstructures and overlapping as well as universal features, probably related to functional aspects (discourse of power). Six sample texts of the text-type `government declaration', two produced in the ex-GDR, four in the united Germany, are analysed. Special attention is paid to similarities and differences (i) in the textual superstructure (problem-solution schema), (ii) in the concepts that reflect the aims of political actions (simple worlds), (iii) in the agents who (are to) perform these actions (concrete vs abstract agents). Similarities are found mainly in the discursive strategies, e.g. legitimization text actions. Differences become obvious in the strategies used for legitimization, and also in the conceptual domains referred to by the problem-solution schema. The metaphors of construction, path and challenge are of particular interest in this respect.

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Targeting of drugs and therapies locally to the esophagus is an important objective in the development of new and more effective dosage forms. Therapies that are retained within the oral cavity for both local and systemic action have been utilized for many years, although delivery to the esophagus has been far less reported. Esophageal disease states, including infections, motility disorders, gastric reflux, and cancers, would all benefit from localized drug delivery. Therefore, research in this area provides significant opportunities. The key limitation to effective drug delivery within the esophagus is sufficient retention at this site coupled with activity profiles to correspond with these retention times; therefore, a suitable formulation needs to provide the drug in a ready-to-work form at the site of action during the rapid transit through this organ. A successfully designed esophageal-targeted system can overcome these obstacles. This review presents a range of dosage form approaches for targeting the esophagus, including bioadhesive liquids and orally retained lozenges, chewing gums, gels, and films, as well as endoscopically delivered therapeutics. The techniques used to measure efficacy both in vitro and in vivo are also discussed. Drug delivery is a growing driver within the pharmaceutical industry and offers benefits both in terms of clinical efficacy, as well as in market positioning, as a means of extending a drug's exclusivity and profitability. Emerging systems that can be used to target the esophagus are reported within this review, as well as the potential of alternative formulations that offer benefits in this exciting area.

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A systematic review was conducted to explicitly identify interventions that alone, or in combination, were effective in improving antibiotic prescribing. The citation search strategy used in the present review provided a database of 365077 studies, of which only twenty-five were included in the final review (“review studies”). Analysis of the interventions used within the review studies indicated that a combination of “guidelines” and “pharmacy” interventions have the greatest potential to improve antibiotic prescribing. Two types of qualitative research were conducted, semi-structured interviews and the collection of naturally occurring data. Semi-structured interviews were conducted in order to determine NHS managers? perceptions of current policies used to improve antibiotic prescribing within selected Primary Care Trusts and highlighted the importance of pharmacy intervention, formularies or guidelines and improved prescribing analysis (IT based intervention) on improving antibiotic prescribing. This was supported by the collection of naturally occurring data, which was used to provide further insight into interventions used to improve antibiotic prescribing. The Specialist Antibiotic Pharmacist (HD) produced and implemented an innovative electronic antibiotic prescribing analysis tool (the Antibiotic Database) to analyse and improve antibiotic prescribing in a consistent manner. The key advantage of the Antibiotic Database was the time and money saved on producing visual electronic outputs containing an inaccurate outcome measure or time period for analysis. The results concluded that an IT based intervention, such as the Antibiotic Database should be used, in addition to the use of antibiotic guidelines and pharmacy intervention, within all sectors of the NHS in order to improve antibiotic prescribing and its analysis.

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This study explores women's perceptions of what made them successful doctoral students and what strategies they used to cope and succeed in the academic environment of an off-campus program in South Florida. The study's theoretical framework was built on Bandura's (1997) theory regarding ways self-efficacy influences choices made and effort expended; and Gilligan (1982), Belenky et al. (1986) and other feminists' theories concerning how women learn. ^ The study included data obtained from individual, semi-structured interviews with 10 participants, documents spanning the 10 years of the program and interviews with founding faculty members. For each, academic resilience was built on (a) viewing that working on the degree was personally fulfilling; (b) believing she possessed a strong sense of academic confidence; (c) priding herself on having self discipline; (d) seeing herself as a role model; and (e) being motivated by a personal or career goal. ^ Strategies the participants used to overcome roadblocks included (a) time management—finding time for personal, professional, and academic duties; (b) focus—making the dissertation a priority; (c) collaboration—utilizing both personal and programmatic assistance; (d) and advocacy—acting on their individual needs. ^ Results of the study indicated that the program at the satellite campus provided structural resources that satisfied basic needs and strengthened the students' self-efficacy. This helped them become successful doctoral graduates. The women had personal fortitude and strong self-efficacy to complete the doctoral journey. They understood that their success was primarily based on the support they received from people: families, peers, and their major professors. Participants suggested that successful women students ascertain whether they have time and resources to devote to an extended study, an understanding family, and the resilience to overcome roadblocks along the way. ^

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An integrated flow and transport model using MIKE SHE/MIKE 11 software was developed to predict the flow and transport of mercury, Hg(II), under varying environmental conditions. The model analyzed the impact of remediation scenarios within the East Fork Poplar Creek watershed of the Oak Ridge Reservation with respect to downstream concentration of mercury. The numerical simulations included the entire hydrological cycle: flow in rivers, overland flow, groundwater flow in the saturated and unsaturated zones, and evapotranspiration and precipitation time series. Stochastic parameters and hydrologic conditions over a five year period of historical hydrological data were used to analyze the hydrological cycle and to determine the prevailing mercury transport mechanism within the watershed. Simulations of remediation scenarios revealed that reduction of the highly contaminated point sources, rather than general remediation of the contaminant plume, has a more direct impact on downstream mercury concentrations.

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The purpose of this action research was to determine what instructional strategies could be used to improve student achievement in fraction addition. An eighth grade intensive math class practiced multiplication facts and hands-on applications of fractions concepts for 2 months. Pretests/posttests were used to measure improvement in computation and understanding.

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It has long been known that vocabulary is essential in the development of reading. Because vocabulary leading to increased comprehension is important, it necessary to determine strategies for ensuring that the best methods of teaching vocabulary are used to help students make gains in vocabulary leading to reading comprehension. According to the National Reading Panel, multiple strategies that involve active engagement on the part of the student are more effective than the use of just one strategy. The purpose of this study was to determine if students' use of visualization, student-generated pictures of onset-and-rime-patterned vocabulary, and story read-alouds with discussion, would enable diverse first-grade students to increase their vocabulary and comprehension. In addition, this study examined the effect of the multimodal framework of strategies on English learners (ELs). This quasi-experimental study (N=69) was conducted in four first-grade classrooms in a low socio-economic school. Two treatment classes used a multimodal framework of strategies to learn weekly vocabulary words and comprehension. Two comparison classrooms used the traditional method of teaching weekly vocabulary and comprehension. Data sources included Florida Assessments for Instruction in Reading (FAIR), comprehension and vocabulary scores, and weekly MacMillan/McGraw Hill Treasures basal comprehension questions and onset-and-rime vocabulary questions. This research determined that the treatment had an effect in adjusted FAIR comprehension means by group, with the treatment group (adj M = 5.14) significantly higher than the comparison group ( adj M = -8.26) on post scores. However, the treatment means did not increase from pre to post, but the comparison means significantly decreased from pre to post as the materials became more challenging. For the FAIR vocabulary, there was a significant difference by group with the comparison adjusted post mean higher than the treatment's, although both groups significantly increased from pre to post. However, the FAIR vocabulary posttest was not part of the Treasures vocabulary, which was taught using the multimodal framework of strategies. The Treasures vocabulary scores were not significantly different by group on the assessment across the weeks, although the treatment means were higher than those of the comparison group. Continued research is needed in the area of vocabulary and comprehension instructional methods in order to determine strategies to increase diverse, urban students' performance.