2,369 research outputs found

    The Impact of Gun Violence on African American Adolescents in Baltimore City, Maryland

    Get PDF
    Goal Statement: The aim of this social change portfolio is to prevent gun violence in African American males in Baltimore City, Maryland, through increasing awareness in schools and communities. Significant Findings: African American males are perpetrators and victims of gun violence at a substantially high rate in Baltimore City, MD. They are disproportionately affected in socioeconomically disadvantaged communities” (Shulman et al., 2021). According to County Health Rankings & Roadmaps (2018), data from 2016 to 2020 revealed 44 firearm-related deaths per 100,000 people in Baltimore City, Maryland, compared to 12 people per 100,000 in the whole state of Maryland and 12 people per 100,000 in the United States. Easy access to illegal weapons, drug turf wars, and low self-efficacy contribute to delinquency, suicides, and homicides of young Black males in Baltimore. Because of its lethality and unpredictability, it seems probable that exposure to gun violence may have uniquely harmful psychological effects” (Shulman et al., 2021). Examining African American males\u27 social-ecological relationships can help determine what interventions and strategies would be the most effective in bringing awareness to gun violence prevention in inner cities. Nisbett’s cultural cognitive theory examines the role of culture and how it affects the intergenerational transmission of violence (Kim, 2012). Nesbitt’s theory can help practitioners understand that some children may become perpetrators of violence through the intergenerational transmission of their parents. Promising Practices Network (2014) states that evidenced-based prevention programs like Big Brothers Big Sisters, located in Baltimore, have successfully diverted young Black males from engaging in violence and severe conduct problems. Objectives/Strategies/Interventions/Next Steps: The objectives of this portfolio are to assess the impact of gun violence on African American males in Baltimore City, MD. To determine how social-ecological systems assist in observing how a child’s development is affected through relationship interaction in the different systems. To determine how Nisbett’s cultural cognitive theory role of culture affects the intergenerational transmission of violence. To assess the outcome of evidence-based youth prevention programs of Big Brothers Big Sisters (BBBS). To explain institutional, community, and public policy barriers and advocacy to preventing gun violence in African American males in urban areas

    The hydrological basis for the protection of water resources to meet environmental and societal requirements.

    Get PDF
    Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.In common with other natural systems, aquatic ecosystems provide a wealth of economically valuable services and long-term benefits to society. However, growing human populations, coupled with increased aspirations for improved quality of life, have lead to intense pressure on the world's finite freshwater resources. Frequently, particularly in developing countries, there are both perceived and genuine incompatibilities between ecological and societal needs for freshwater. Environmental Flow Assessment (EFA) is essentially a tool for water resources management and its ultimate goal should be the integration of ecological and societal systems. While other ecological components (i.e. biological and geomorphological) are equally important to EFA, this thesis investigates the role of the hydrological cycle and the hydrological regime in providing the ecosystem goods and services upon which society depends. Ecological and societal systems operate at different temporal, spatial and organisational scales and hydronomic zoning or sub-zoning is proposed as an appropriate water resources management technique for matching these different scales. A major component of this thesis is a review of the South African water resources management framework and, in particular, the role of the Reserve (comprising a basic human right to survival water as well as an ecological right of the aquatic resource to maintain ecological functioning) in facilitating ecologically sustainable water resources management. South African water resources management is in the early stages of water allocation reform and the Department of Water Affairs and Forestry has stated that "the water allocation process must allow for the sustainable use of water resources and must promote the efficient and non-wasteful use of water". Thus, new ways of approaching the compromise between ecological and societal needs for freshwater water are required. This thesis argues that this requires that the focus of freshwater ecosystems be extended beyond the aquatic resource, so that societal activities on the catchment are linked to the protection of instream flows. Streamflow variability plays a major role in structuring the habitat templates that sustain aquatic and riparian ecological functioning and has been associated with increased biodiversity. Biodiversity and societal well-being are interlinked. However, there is a need in EFA for knowledge of the most influential components of the streamflow regime in order that stakeholders may anticipate any change in ecosystem goods and services as a result of their disruption to the hydrological cycle. The identification of high information hydrological indicators for characterising highly variable streamflow regimes is useful to water resources management, particularly where thresholds of streamflow regime characteristics have ecological relevance. Several researchers have revisited the choice of hydrological indices in order to ascertain whether some indices explain more of the hydrological variability in different aspects of streamflow regimes than others. However, most of the research relating to hydrological indices has focused primarily on regions with temperate climates. In this thesis multivariate analysis is applied to a relatively large dataset of readily computed ecologically relevant hydrological indices (including the Indicators of Hydrological Alteration and the South African Desktop Reserve Model indices) extracted from long-term records of daily flows at 83 sites across South Africa. Principal Component Analysis is applied in order to highlight general patterns of intercorrelation, or redundancy, among the indices and to identify a minimum subset of hydrological indices which explain the majority of the variation among the indices of different components of the streamflow regimes found in South Africa. The results indicate the value of including several of the IHA indices in EFAs for South African rivers. Statistical analysis is meaningful only when calculated for a sufficiently long hydrological record, and in this thesis the length of record necessary to obtain consistent hydrological indices, with minimal influence of climatic variation, is investigated. The results provide a guide to the length of record required for analysis of the high information hydrological indices representing the main components of the streamflow regime, for different streamflow types. An ecosystem-based approach which recognises the hydrological connectivity of the catchment landscape in linking aquatic and terrestrial systems is proposed as a framework for ecologically sustainable water resources management. While this framework is intended to be generic, its potential for application in the South African Water Allocation Reform is illustrated with a case study for the Mkomazi Catchment in KwaZulu-Natal. Hydronomic sub-zoning, based on the way in which societal activities disrupt the natural hydrological processes, both off-stream and instream, is applied to assess the incompatibilities between societal and ecological freshwater needs. Reference hydrological, or pre-development, conditions in the Mkomazi Catchment are simulated using the ACRU agrohydrological model. Management targets, based on the statistical analysis of pre-development streamflow regimes, are defined to assess the degree of hydrological alteration in the high information hydrological indices of the Mkomazi Catchment as a result of different societal activities. Hydrological alteration from predevelopment conditions is assessed using the Range of Variability Approach. The results indicate that the proposed framework is useful to the formulation of stakeholder-based catchment management plans. Applying hydrological records (either observed or simulated) as an ecological resource is highly appropriate for assessing the variability that ecosystems need to maintain the biodiversity, ecological functioning and resilience that people and society desire

    Hydrological modelling applications for water resources management in the Mkomazi Catchment.

    Get PDF
    Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.Predictions that water shortages will constrain economic growth in South Africa by 2025 have led to increased concerns among water resource managers that there is a need for comprehensive water management strategies. To this extent the new South African Water Act requires that water resource allocation be approached in a more equitable and conservative way than in the past in order to sustain water resources for catchment development. This includes protection of the water resource base by the setting aside of a health Reserve for basic human needs and for the ecological functioning of rivers. At a time when water resource management is shifting from the practice of large dam construction to reconciling water demand with water supply in more holistic strategies, the Mkomazi Catchment in KwaZulu-Natal provides an opportunity to investigate some of the major issues that dominate contemporary water resource management. Presently (2001), there are no impoundments on the Mkomazi River and the catchment is generally underdeveloped. These factors have provided the impetus for the Department of Water Affairs and Forestry's proposed inter-basin transfer scheme to use the surplus flow in the Mkomazi Catchment to augment the water resources of the neighbouring Mgeni system. Impact-of-Iand-use and development scenario studies, using the ACRU agrohydrological modelling system, were performed to simulate the impacts of (a) baseline land cover, (b) present land use, (c) the first phase of the Mkomazi-Mgeni Transfer Scheme and (d) potential climate change on the hydrological dynamics of the Mkomazi Catchment. The results indicate that the change from baseline land cover conditions to present land use conditions has little impact on the annual water resources of the Mkomazi River. This is especially so in the upper catchment where there is little anthropogenic development and from where the planned inter-basin transfer will be made from the proposed Smithfield Dam. Although the impacts of commercial forestry and irrigation in the middle and lower catchment impose local stress on streamflow generation, they do not detract substantially from the main downstream flows. Evaluation of the impacts of the proposed Smithfield Dam on annual streamflow generation revealed that there is more than sufficient water in the upper Mkomazi Catchment to sustain the inter-basin transfer under present climatic conditions. However, under potential climate change the median annual Mkomazi streamflows at the estuary could be reduced by 46% if the dam was constructed, compared with a 22% reduction under present climatic conditions. The impacts of catchment development on the seasonal low flows within the Mkomazi Catchment indicated that those areas which are already heavily utilised by afforestation and, particularly, by irrigated land use are unlikely to be able to support any further large scale commercial agricultural development, even under present climatic conditions. Water management strategies for the Mgeni system will impact on potential water allocation within the Mkomazi Catchment. The results of the impacts studies were used to assess the water demand of the major water-use sectors and the availability of streamflows for further allocation was assessed. Present total annual water demands of Mkomazi streamflows is minimal. Even allowing for the environmental demand in the Mkomazi Catchment, as identified by the Building Block Methodology during an instream flow requirements workshop, as well as the first phase of the inter-basin transfer, there would be surpluses of 66%, 43%, 42% and 45% of streamflows, respectively, at the four instream flow requirement sites on the Mkomazi River. The results of the Mkomazi instream flow requirements workshop were revisited to assess the achievability of the recommended flows within the ACRU generated daily time series of streamflows for each of the scenarios simulated, at the each of the four instream flow requirement sites on the Mkomazi River. The results confirmed the need to ascertain the Mkomazi River's natural flow variability, and to assess how much alteration is likely under development of the Mkomazi Catchment. The Indicators of Hydrologic Alteration and Range of Variability Approach methodologies were used to determine which components of the streamflow regime would be most impacted by the inter-basin transfer. Hypothetical, yet realistic, upper and lower management target thresholds were applied to determine the range of variation experienced by the streamflow regime of the Mkomazi, under both pre- and post-dam construction conditions, and to evaluate a preliminary assessment of the characteristics of the streamflow regime required to meet environmental sustainability. The issues raised by potentially conflicting water uses within catchments in South Africa have indicated that any approach to address the increasing complexity of water resource problems, and the management thereof, requires effective hydrological modelling

    Investigating Pre-Service Teachers’ Perceptions of the Virginia Computer Science Standards of Learning: A Qualitative Multiple Case Study

    Get PDF
    Computer science education is being recognized globally as necessary to better prepare students in all grade levels, K-12, for future success. As a result of this focus on computer science education in the United States and around the world, there is an increased demand for highly qualified teachers with content and pedagogical knowledge to successfully support student learning. As a result, there is a call to include and improve the computer science training offered to pre-service teachers in their educator preparation programs from methods courses to practicum and student teaching experiences. Thus, it is important to understand how pre-service teachers view content, classroom practices, and teaching and learning methodologies and theories to inform teacher educators about best practices for integrating computer science. This multi-case study investigated pre-service teachers’ perceived abilities and intent to integrate the Virginia Computer Science Standards of Learning into future content area instruction, as well as any shifts that occurred in these pre-service teachers’ perceptions as a result of their student teaching experience. Five elementary pre-service teachers enrolled in a teacher preparation program at a large, public research university in the Mid-Atlantic region of the United States comprised the cases in this research study. Data were collected during the participants’ student teaching experience and final semester in their respective programs and was comprised of the following: pre-, mid-, and post-questionnaires, meeting transcriptions (2), semi-structured individual phone interview transcriptions (2), and written/posted exchanges on an online discussion board. Data representing each case were analyzed using a qualitative general inductive approach as outlined by Thomas. A within-case analysis was performed to develop main categories and identify central themes for each case, and a cross-case analysis was then conducted using the NVivo Qualitative Data Analysis Software. The findings revealed similarities and differences across the cases, as well as perceived challenges and benefits to incorporating computer science and the Virginia Computer Science Standards of Learning into future content area lessons as determined by elementary pre-service teachers. Findings from this study can be used to inform and improve pre-service teacher education as well as provide insight to school administrators

    Multi-century variability in the Pacific North American circulation pattern reconstructed from tree rings

    Get PDF
    We here present a reconstruction (1725-1999) of the winter Pacific North American (PNA) pattern based on three winter climate sensitive tree ring records from the western USA. Positive PNA phases in our record are associated with warm phases of ENSO and PDO and the reorganization of the PNA pattern towards a positive mode is strongest when ENSO and PDO are in phase. Regime shifts in our PNA record correspond to climatic shifts in other proxies of Pacific climate variability, including two well-documented shifts in the instrumental period (1976 and 1923). The correspondence breaks down in the early 19th century, when our record shows a prolonged period of positive PNA, with a peak in 1800-1820. This period corresponds to a period of low solar activity (Dalton Minimum), suggesting a ‘positive PNA like' response to decreased solar irradiance. The distinct 30-year periodicity that dominates the PNA reconstruction in the 18th century and again from 1875 onwards is disrupted during this perio

    The Role of Adipokines in Understanding the Associations between Obesity and Depression

    Get PDF
    Objective. Two major causes of disability, major depression and obesity, share overlapping psychosocial and pathophysiological etiologies. Studies are now focused on biological mechanisms linking the two illnesses, and there is interest in the role that adipokines may have in mediating the association between obesity and depression. We reviewed the literature to look at what is currently known about this association, focusing on the adipokines leptin, adiponectin, and resistin. Methods. A MEDLINE search, citing articles from 1966 onward, supplemented by a review of bibliographies, was conducted to identify relevant studies. Results. This paper identified plausible pathways underlying a link between adipokines and depression. Only a few studies have yet been conducted specifically examining these biomarkers in patients with depression, but the results are intriguing. Conclusion. This paper is one of the first to examine the association between adipokines and depression. It provides an overview of the physiological role of adipokines and summarizes the data suggesting that they may be dysregulated in major depression. This area of research may become increasingly important as new treatment strategies are developed

    Autotuning Apache TVM-based Scientific Applications Using Bayesian Optimization

    Full text link
    Apache TVM (Tensor Virtual Machine), an open source machine learning compiler framework designed to optimize computations across various hardware platforms, provides an opportunity to improve the performance of dense matrix factorizations such as LU (Lower Upper) decomposition and Cholesky decomposition on GPUs and AI (Artificial Intelligence) accelerators. In this paper, we propose a new TVM autotuning framework using Bayesian Optimization and use the TVM tensor expression language to implement linear algebra kernels such as LU, Cholesky, and 3mm. We use these scientific computation kernels to evaluate the effectiveness of our methods on a GPU cluster, called Swing, at Argonne National Laboratory. We compare the proposed autotuning framework with the TVM autotuning framework AutoTVM with four tuners and find that our framework outperforms AutoTVM in most cases

    Inactivating the spindle checkpoint kinase Bub1 during embryonic development results in a global shutdown of proliferation

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Bub1 is a component of the spindle assembly checkpoint, a surveillance mechanism that maintains chromosome stability during M-phase. Bub1 is essential during the early stages of embryogenesis, with homozygous <it>BUB1</it>-null mice dying shortly after day E3.5. Bub1 is also required later during embryogenesis; inactivation of <it>BUB1 </it>on day E10.5 appears to rapidly block all further development. However, the mechanism(s) responsible for this phenotype remain unclear.</p> <p>Findings</p> <p>Here we show that inactivating <it>BUB1 </it>on day E10.5 stalls embryogenesis within 48 hours. This is accompanied by a global shutdown of proliferation, widespread apoptosis and haemorrhaging.</p> <p>Conclusion</p> <p>Our results suggest that Bub1 is required throughout the developing embryo for cellular proliferation. Therefore, Bub1 has been shown to be essential in all scenarios analyzed thus far in mice: proliferation of cultured fibroblasts, spermatogenesis, oogenesis and both early and late embryonic development. This likely reflects the fact that Bub1 has dual functions during mitosis, being required for both SAC function and chromosome alignment.</p
    corecore