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Sample records for african setting methods

  1. African Swine Fever in Uganda: Qualitative Evaluation of Three Surveillance Methods with Implications for Other Resource-Poor Settings

    PubMed Central

    Chenais, Erika; Sternberg-Lewerin, Susanna; Boqvist, Sofia; Emanuelson, Ulf; Aliro, Tonny; Tejler, Emma; Cocca, Giampaolo; Masembe, Charles; Ståhl, Karl

    2015-01-01

    Animal diseases impact negatively on households and on national economies. In low-income countries, this pertains especially to socio-economic effects on household level. To control animal diseases and mitigate their impact, it is necessary to understand the epidemiology of the disease in its local context. Such understanding, gained through disease surveillance, is often lacking in resource-poor settings. Alternative surveillance methods have been developed to overcome some of the hurdles obstructing surveillance. The objective of this study was to evaluate and qualitatively compare three methods for surveillance of acute infectious diseases using African swine fever in northern Uganda as an example. Report-driven outbreak investigations, participatory rural appraisals (PRAs), and a household survey using a smartphone application were evaluated. All three methods had good disease-detecting capacity, and each of them detected many more outbreaks compared to those reported to the World Organization for Animal Health during the same time period. Apparent mortality rates were similar for the three methods although highest for the report-driven outbreak investigations, followed by the PRAs, and then the household survey. The three methods have different characteristics and the method of choice will depend on the surveillance objective. The optimal situation might be achieved by a combination of the methods: outbreak detection via smartphone-based real-time surveillance, outbreak investigation for collection of biological samples, and a PRA for a better understanding of the epidemiology of the specific outbreak. All three methods require initial investments and continuous efforts. The sustainability of the surveillance system should, therefore, be carefully evaluated before making such investments. PMID:26664978

  2. Implementation of Evidence-Based HIV Interventions for Young Adult African American Women in Church Settings

    PubMed Central

    Stewart, Jennifer M.

    2015-01-01

    Objective To assess the barriers and facilitators to using African American churches as sites for implementation of evidence-based HIV interventions among young African American women. Design Mixed methods cross-sectional design. Setting African American churches in Philadelphia, PA. Participants 142 African American pastors, church leaders, and young adult women ages 18 to 25. Methods Mixed methods convergent parallel design. Results The majority of young adult women reported engaging in high-risk HIV-related behaviors. Although church leaders reported willingness to implement HIV risk-reduction interventions, they were unsure of how to initiate this process. Key facilitators to the implementation of evidence-based interventions included the perception of the leadership and church members that HIV interventions were needed and that the church was a promising venue for them. A primary barrier to implementation in this setting is the perception that discussions of sexuality should be private. Conclusion Implementation of evidence-based HIV interventions for young adult African American women in church settings is feasible and needed. Building a level of comfort in discussing matters of sexuality and adapting existing evidence-based interventions to meet the needs of young women in church settings is a viable approach for successful implementation. PMID:25139612

  3. Fighting through Resistance: Challenges Faced by African American Women Principals in Predominately White School Settings

    ERIC Educational Resources Information Center

    Jackson, Alicia D.

    2013-01-01

    African American women represented a growing proportion within the field of education in attaining leadership roles as school principals. As the numbers continued to rise slowly, African American women principals found themselves leading in diverse or even predominately White school settings. Leading in such settings encouraged African American…

  4. The Mapmark Standard Setting Method

    ERIC Educational Resources Information Center

    Schulz, E. Matthew; Mitzel, Howard C.

    2005-01-01

    A new standard setting method, Mapmark, was recently developed by ACT Inc. in the course of a contract with the National Assessment Governing Board (NAGB) to set achievement levels for the 2005 National Assessment of Educational Progress (NAEP) in Grade 12 mathematics. Mapmark includes elements of the bookmark method (Lewis, Mitzel, & Green, 1996;…

  5. African Dance Aesthetics in a K-12 Dance Setting: From History to Social Justice

    ERIC Educational Resources Information Center

    Ward, Sheila A.

    2013-01-01

    This article invites the reader to gain a deeper understanding of the aesthetics of African-based dance through the elements of tradition, transformation, and social justice. A discussion of the aesthetics of African dances within Africa and throughout the African diaspora opens the doors to present these dances in a K-12 setting, to explore a…

  6. An adaptive level set method

    SciTech Connect

    Milne, R.B.

    1995-12-01

    This thesis describes a new method for the numerical solution of partial differential equations of the parabolic type on an adaptively refined mesh in two or more spatial dimensions. The method is motivated and developed in the context of the level set formulation for the curvature dependent propagation of surfaces in three dimensions. In that setting, it realizes the multiple advantages of decreased computational effort, localized accuracy enhancement, and compatibility with problems containing a range of length scales.

  7. Liner setting tool and method

    SciTech Connect

    Baugh, J.L.; Fraser, J.M. III; Melenyzer, G.J.

    1989-07-18

    This paper describes a liner setting apparatus for setting a liner suspended from a tubular string in a subterranean well and for releasing from a set liner hanger to permit retrieval of the liner setting apparatus and the tubular string. The liner hanger including gripping members for bitting engagement with side walls of the wellbore in response to axial movement of the tubular string, the liner setting apparatus, and the liner within the well bore, and interior threads for threaded engagement and disengagement with the liner setting apparatus. The liner setting apparatus comprising: a tubular mandrel; a nut positioned about the tubular mandrel; a setting ring assembly positioned about the tubular mandrel and axially spaced between the nut and the upper end of the tubular mandrel. The setting ring assembly including: an annular torque control ring, one or more fingers each axially movable with respect to the torque control ring; a plurality of sleeves each positioned about the tubular mandrel and axially movable with respect to the torque control ring and with respect to each other, an actuating member radially moveable from a lock position such that the actuating member is within one of the plurality of locking recesses and the locking sleeves are axially adjacent each other, to an unlock position such that the actuating member is moved radially outwardly by engagement with the ramp surface during axial movement of the annular setting ring assembly, such that the actuating member separates the sleeves axially during radially outward movement thereof and thereby axially moves each of the one or more fingers to the unlock position.

  8. Using the Afrocentric Method in Researching Indigenous African Culture

    ERIC Educational Resources Information Center

    Mkabela, Queeneth

    2005-01-01

    The article highlights the realities and dynamics facing researchers researching indigenous African culture. The cultural aspirations, understandings, and practices of African indigenous people should position researchers to implement and organize the research process. Suggestions are also made for implementing the "Afrocentric method," and how to…

  9. A Multi-Level Approach for Promoting HIV Testing Within African American Church Settings

    PubMed Central

    2015-01-01

    Abstract The African American church is a community-based organization that is integral to the lives, beliefs, and behaviors of the African American community. Engaging this vital institution as a primary setting for HIV testing and referral would significantly impact the epidemic. The disproportionately high HIV incidence rate among African Americans dictates the national priority for promotion of early and routine HIV testing, and suggests engaging community-based organizations in this endeavor. However, few multilevel HIV testing frameworks have been developed, tested, and evaluated within the African American church. This article proposes one such framework for promoting HIV testing and referral within African American churches. A qualitative study was employed to examine the perceptions, beliefs, knowledge, and behaviors related to understanding involvement in church-based HIV testing. A total of four focus groups with church leaders and four in-depth interviews with pastors, were conducted between November 2012 and June 2013 to identify the constructs most important to supporting Philadelphia churches' involvement in HIV testing, referral, and linkage to care. The data generated from this study were analyzed using a grounded theory approach and used to develop and refine a multilevel framework for identifying factors impacting church-based HIV testing and referral and to ultimately support capacity building among African American churches to promote HIV testing and linkage to care. PMID:25682887

  10. Implementing Conjoint Behavioral Consultation for African American Children from a Low-SES, Urban Setting

    ERIC Educational Resources Information Center

    Ohmstede, Tammi J.; Yetter, Georgette

    2015-01-01

    This study investigated the effectiveness of conjoint behavioral consultation (CBC) for addressing externalizing behavior concerns in African American children at home and school in a low-socioeconomic status (SES), urban setting. A small-n, multiple-baseline design was employed across participants. Three of the six caregivers were unable to…

  11. Leading School Improvement: African American Women Principals in Urban Educational Settings

    ERIC Educational Resources Information Center

    Mack, Yejide S.

    2010-01-01

    African American women administrators working in urban educational settings have been found to be effective leaders of school improvement. Underutilized women and people of color are the untapped value that organizations of all types need to enhance creativity, change efforts, teamwork, and financial benefits (Northouse, 2001). During the last…

  12. Framing African American Students' Success and Failure in Urban Settings: A Typology for Change

    ERIC Educational Resources Information Center

    Lewis, Chance W.; James, Marlon; Hancock, Stephen; Hill-Jackson, Valerie

    2008-01-01

    Grounded in critical race theory, this article seeks to frame the ideological positions of success and failure for African American students in urban school settings. First, we revisit national data and research literature that illustrate the ongoing urban Black-White achievement gap. Second, the Matrix of Achievement Paradigms is shared in an…

  13. HIV stigma and discrimination in medical settings: stories from African women in New Zealand.

    PubMed

    Cannon Poindexter, Cynthia

    2013-01-01

    Recent changes in New Zealand's HIV and immigration situations have sparked a need to understand the experiences of HIV-positive African newcomers there. Here a narrative lens was brought to a previous qualitative study to harvest stories about discrimination in medical settings in New Zealand, told by four HIV-positive African women. Despite describing positive experiences with specialist HIV providers, their accounts shed light on weaknesses within the health care system regarding the rights and treatment of immigrants living with HIV. Participants reported inappropriate use of universal precautions, violations of confidentiality rights, discriminatory comments about Africans or persons with HIV, and misinformation about HIV transmission. Interventions must include enforcement of The Privacy Law and consistent training and monitoring of employee behavior in health care organizations. PMID:24028736

  14. Wilms’ tumour: Determinants of prognosis in an African setting

    PubMed Central

    Atanda, Akinfenwa Taoheed; Anyanwu, Lofty-John Chuhwuemeka; Atanda, Oladoyin Jareenat; Mohammad, Aminu Mohammad; Abdullahi, Lawal Barau; Farinyaro, Aliyu Umar

    2015-01-01

    Background: The few studies available in the literature on Wilms’ tumour (WT) from sub-Saharan Africa have reported a dismal outcome for children with the tumour. This study evaluated the risk factors that have been correlated with outcome in the literature and compare these with outcome among our patients. Materials and Methods: Cases of histologically confirmed WT between 2009 and 2013 in a tertiary hospital in Northwestern Nigeria were evaluated for gender, age, laterality, symptoms, duration before presentation, stage at presentation, histologic subtype and p53 mutation. These were then correlated with outcome. Results: Totally, 30 cases of WT were diagnosed with mean age of 4.8 ± 1.9 years; and male:female ratio of 2:1. No statistically significant relationship with outcome was found for gender (P = 0.138) or histologic subtype (P = 0.671). The most significant variables which positively influenced the outcome were presentation at earlier stages (P = 0.007) and completion of therapy (P = 0.0007). p53 mutation was seen in 3 (16.7%) of 18 cases and was not associated with a poor outcome (P = 0.089). However, 2 of the 3 cases presented in Stage IV and none of them survived the 1st year. Conclusion: This study shows that even though p53 mutation was associated with a more aggressive phenotype, the most significant determinants of a good outcome among patients in a developing country like ours is non-blastemal dominant histologic subtype, early stage at presentation and completion of therapy. PMID:26612121

  15. Issues and Methods for Standard-Setting.

    ERIC Educational Resources Information Center

    Hambleton, Ronald K.; And Others

    Issues involved in standard setting along with methods for standard setting are reviewed, with specific reference to their relevance for criterion referenced testing. Definitions are given of continuum and state models, and traditional and normative standard setting procedures. Since continuum models are considered more appropriate for criterion…

  16. Reliability and Validity of Instruments for Assessing Perinatal Depression in African Settings: Systematic Review and Meta-Analysis

    PubMed Central

    Tsai, Alexander C.; Scott, Jennifer A.; Hung, Kristin J.; Zhu, Jennifer Q.; Matthews, Lynn T.; Psaros, Christina; Tomlinson, Mark

    2013-01-01

    Background A major barrier to improving perinatal mental health in Africa is the lack of locally validated tools for identifying probable cases of perinatal depression or for measuring changes in depression symptom severity. We systematically reviewed the evidence on the reliability and validity of instruments to assess perinatal depression in African settings. Methods and Findings Of 1,027 records identified through searching 7 electronic databases, we reviewed 126 full-text reports. We included 25 unique studies, which were disseminated in 26 journal articles and 1 doctoral dissertation. These enrolled 12,544 women living in nine different North and sub-Saharan African countries. Only three studies (12%) used instruments developed specifically for use in a given cultural setting. Most studies provided evidence of criterion-related validity (20 [80%]) or reliability (15 [60%]), while fewer studies provided evidence of construct validity, content validity, or internal structure. The Edinburgh postnatal depression scale (EPDS), assessed in 16 studies (64%), was the most frequently used instrument in our sample. Ten studies estimated the internal consistency of the EPDS (median estimated coefficient alpha, 0.84; interquartile range, 0.71-0.87). For the 14 studies that estimated sensitivity and specificity for the EPDS, we constructed 2 x 2 tables for each cut-off score. Using a bivariate random-effects model, we estimated a pooled sensitivity of 0.94 (95% confidence interval [CI], 0.68-0.99) and a pooled specificity of 0.77 (95% CI, 0.59-0.88) at a cut-off score of ≥9, with higher cut-off scores yielding greater specificity at the cost of lower sensitivity. Conclusions The EPDS can reliably and validly measure perinatal depression symptom severity or screen for probable postnatal depression in African countries, but more validation studies on other instruments are needed. In addition, more qualitative research is needed to adequately characterize local

  17. Level set method for microfabrication simulations

    NASA Astrophysics Data System (ADS)

    Baranski, Maciej; Kasztelanic, Rafal; Albero, Jorge; Nieradko, Lukasz; Gorecki, Christophe

    2010-05-01

    The article describes application of Level Set method for two different microfabrication processes. First is shape evolution of during reflow of the glass structure. Investigated problem were approximated by viscous flow of material thus kinetics of the process were known from physical model. Second problem is isotropic wet etching of silicon. Which is much more complicated because dynamics of the shape evolution is strongly coupled with time and geometry shapes history. In etching simulations Level Set method is coupled with Finite Element Method (FEM) that is used for calculation of etching acid concentration that determine geometry evolution of the structure. The problem arising from working with FEM with time varying boundaries was solved with the use of the dynamic mesh technique employing the Level Set formalism of higher dimensional function for geometry description. Isotropic etching was investigated in context of mico-lenses fabrication. Model was compared with experimental data obtained in etching of the silicon moulds used for micro-lenses fabrication.

  18. Who We Are: (In)visible African American Women Setting Traditions of Excellence and Paving Paths for Transformation

    ERIC Educational Resources Information Center

    O'Bryant, Camille

    2015-01-01

    The purpose of this lecture is to provide the voice and visibility of African American women who have upheld the tradition of excellence set by Amy Morris Homans in the development of physical education in higher education for women and set pathways to transition our field to be more inclusive and diverse and have served as transformative leaders…

  19. The Objective Borderline Method: A Probabilistic Method for Standard Setting

    ERIC Educational Resources Information Center

    Shulruf, Boaz; Poole, Phillippa; Jones, Philip; Wilkinson, Tim

    2015-01-01

    A new probability-based standard setting technique, the Objective Borderline Method (OBM), was introduced recently. This was based on a mathematical model of how test scores relate to student ability. The present study refined the model and tested it using 2500 simulated data-sets. The OBM was feasible to use. On average, the OBM performed well…

  20. The role of dermatopathology in conjunction with teledermatology in resource-limited settings: lessons from the African Teledermatology Project

    PubMed Central

    Tsang, Matthew W.; Kovarik, Carrie L.

    2013-01-01

    Background Access to dermatology and dermatopathology services is scarce in sub-Saharan Africa. Teledermatology provides consultations for healthcare providers in resource-limited settings where specialty medical services are difficult to obtain, and the African Teledermatology Project has helped to bridge the gap in dermatological care in Africa. This program also allows for biopsy specimens to be sent to the USA for processing in cases where the clinical diagnosis is difficult and definitive diagnosis has implications for patient management. This study characterizes conditions diagnosed through clinicopathological correlation in conjunction with photos and tissue submitted to the African Teledermatology Project. Materials and methods Retrospective case review of tissue specimens submitted over three years. Results Fifty-five biopsy specimens met inclusion criteria and represent cases of malignancy (35%), infection (7%), suspected infection (15%), lichenoid tissue reaction (5%), dermatitis (15%), and other various conditions (18%). Three biopsy specimens were non-diagnostic (5%). Clinicopathological concordance between submitting clinician and biopsy results occurred in 32 out of 55 cases (58%). Clinical and pathological diagnoses differed in 21 out of 55 cases (38%). Kaposi sarcoma (KS) represents the clinical diagnosis most often suspected in the evaluated biopsy specimens (42%) and was correctly recognized clinically in 13 out of 23 cases (57%). Conclusion Clinical images may not provide sufficient information to definitively diagnose certain infectious and malignant dermatological conditions submitted through telemedicine consultation. Microscopic examination of skin biopsy specimens is an important adjunct for accurate diagnosis of disease and determination of appropriate treatment strategies. PMID:21244377

  1. Evaluation of a health setting-based stigma intervention in five African countries.

    PubMed

    Uys, Leana; Chirwa, Maureen; Kohi, Thecla; Greeff, Minrie; Naidoo, Joanne; Makoae, Lucia; Dlamini, Priscilla; Durrheim, Kevin; Cuca, Yvette; Holzemer, William L

    2009-12-01

    The study aim is to explore the results of an HIV stigma intervention in five African health care settings. A case study approach was used. The intervention consisted of bringing together a team of approximately 10 nurses and 10 people living with HIV or AIDS (PLHA) in each setting and facilitating a process in which they planned and implemented a stigma reduction intervention, involving both information giving and empowerment. Nurses (n = 134) completed a demographic questionnaire, the HIV/AIDS Stigma Instrument-Nurses (HASI-N), a self-efficacy scale, and a self-esteem scale, both before and after the intervention, and the team completed a similar set of instruments before and after the intervention, with the PLHA completing the HIV/AIDS Stigma Instrument for PLHA (HASI-P). The intervention as implemented in all five countries was inclusive, action-oriented, and well received. It led to understanding and mutual support between nurses and PLHA and created some momentum in all the settings for continued activity. PLHA involved in the intervention teams reported less stigma and increased self-esteem. Nurses in the intervention teams and those in the settings reported no reduction in stigma or increases in self- esteem and self-efficacy, but their HIV testing behavior increased significantly. This pilot study indicates that the stigma experience of PLHA can be decreased, but that the stigma experiences of nurses are less easy to change. Further evaluation research with control groups and larger samples and measuring change over longer periods of time is indicated. PMID:20025515

  2. Evaluation of a Health Setting-Based Stigma Intervention in Five African Countries

    PubMed Central

    Uys, Leana; Chirwa, Maureen; Kohi, Thecla; Greeff, Minrie; Makoae, Lucia; Dlamini, Priscilla; Durrheim, Kevin; Cuca, Yvette; Holzemer, William L.

    2009-01-01

    Abstract The study aim is to explore the results of an HIV stigma intervention in five African health care settings. A case study approach was used. The intervention consisted of bringing together a team of approximately 10 nurses and 10 people living with HIV or AIDS (PLHA) in each setting and facilitating a process in which they planned and implemented a stigma reduction intervention, involving both information giving and empowerment. Nurses (n = 134) completed a demographic questionnaire, the HIV/AIDS Stigma Instrument-Nurses (HASI-N), a self-efficacy scale, and a self-esteem scale, both before and after the intervention, and the team completed a similar set of instruments before and after the intervention, with the PLHA completing the HIV/AIDS Stigma Instrument for PLHA (HASI-P). The intervention as implemented in all five countries was inclusive, action-oriented, and well received. It led to understanding and mutual support between nurses and PLHA and created some momentum in all the settings for continued activity. PLHA involved in the intervention teams reported less stigma and increased self-esteem. Nurses in the intervention teams and those in the settings reported no reduction in stigma or increases in self- esteem and self-efficacy, but their HIV testing behavior increased significantly. This pilot study indicates that the stigma experience of PLHA can be decreased, but that the stigma experiences of nurses are less easy to change. Further evaluation research with control groups and larger samples and measuring change over longer periods of time is indicated. PMID:20025515

  3. Influences on Healthcare-seeking during Final Illnesses of Infants in Under-resourced South African Settings

    PubMed Central

    Chopra, Mickey; Jackson, Debra; Winch, Peter J.; Minkovitz, Cynthia S

    2011-01-01

    To examine how health caregivers in under-resourced South African settings select from among the healthcare alternatives available to them during the final illness of their infants, qualitative interviews were conducted with 39 caregivers of deceased infants in a rural community and an urban township. Nineteen local health providers and community leaders were also interviewed to ascertain opinions about local healthcare and other factors impacting healthcare-seeking choices. The framework analysis method guided qualitative analysis of data. Limited autonomy of caregivers in decision-making, lack of awareness of infant danger-signs, and identification of an externalizing cause of illness were important influences on healthcare-seeking during illnesses of infants in these settings. Health system factors relating to the performance of health workers and the accessibility and availability of services also influenced healthcare-seeking decisions. Although South African public-health services are free, the findings showed that poor families faced other financial constraints that impacted their access to healthcare. Often there was not one factor but a combination of factors occurring either concurrently or sequentially that determined whether, when, and from where outside healthcare was sought during final illnesses of infants. In addition to reducing health system barriers to healthcare, initiatives to improve timely and appropriate healthcare-seeking for sick infants must take into consideration ways to mitigate contextual problems, such as limited autonomy of caregivers in decision-making, and reconcile local explanatory models of childhood illnesses that may not encourage healthcare-seeking at allopathic services. PMID:21957677

  4. Bushmeat genetics: setting up a reference framework for the DNA typing of African forest bushmeat.

    PubMed

    Gaubert, Philippe; Njiokou, Flobert; Olayemi, Ayodeji; Pagani, Paolo; Dufour, Sylvain; Danquah, Emmanuel; Nutsuakor, Mac Elikem K; Ngua, Gabriel; Missoup, Alain-Didier; Tedesco, Pablo A; Dernat, Rémy; Antunes, Agostinho

    2015-05-01

    The bushmeat trade in tropical Africa represents illegal, unsustainable off-takes of millions of tons of wild game - mostly mammals - per year. We sequenced four mitochondrial gene fragments (cyt b, COI, 12S, 16S) in >300 bushmeat items representing nine mammalian orders and 59 morphological species from five western and central African countries (Guinea, Ghana, Nigeria, Cameroon and Equatorial Guinea). Our objectives were to assess the efficiency of cross-species PCR amplification and to evaluate the usefulness of our multilocus approach for reliable bushmeat species identification. We provide a straightforward amplification protocol using a single 'universal' primer pair per gene that generally yielded >90% PCR success rates across orders and was robust to different types of meat preprocessing and DNA extraction protocols. For taxonomic identification, we set up a decision pipeline combining similarity- and tree-based approaches with an assessment of taxonomic expertise and coverage of the GENBANK database. Our multilocus approach permitted us to: (i) adjust for existing taxonomic gaps in GENBANK databases, (ii) assign to the species level 67% of the morphological species hypotheses and (iii) successfully identify samples with uncertain taxonomic attribution (preprocessed carcasses and cryptic lineages). High levels of genetic polymorphism across genes and taxa, together with the excellent resolution observed among species-level clusters (neighbour-joining trees and Klee diagrams) advocate the usefulness of our markers for bushmeat DNA typing. We formalize our DNA typing decision pipeline through an expert-curated query database - DNA BUSHMEAT - that shall permit the automated identification of African forest bushmeat items. PMID:25264212

  5. Etch Profile Simulation Using Level Set Methods

    NASA Technical Reports Server (NTRS)

    Hwang, Helen H.; Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

    1997-01-01

    Etching and deposition of materials are critical steps in semiconductor processing for device manufacturing. Both etching and deposition may have isotropic and anisotropic components, due to directional sputtering and redeposition of materials, for example. Previous attempts at modeling profile evolution have used so-called "string theory" to simulate the moving solid-gas interface between the semiconductor and the plasma. One complication of this method is that extensive de-looping schemes are required at the profile corners. We will present a 2D profile evolution simulation using level set theory to model the surface. (1) By embedding the location of the interface in a field variable, the need for de-looping schemes is eliminated and profile corners are more accurately modeled. This level set profile evolution model will calculate both isotropic and anisotropic etch and deposition rates of a substrate in low pressure (10s mTorr) plasmas, considering the incident ion energy angular distribution functions and neutral fluxes. We will present etching profiles of Si substrates in Ar/Cl2 discharges for various incident ion energies and trench geometries.

  6. Challenges to HIV prevention in psychiatric settings: Perceptions of South African mental health care providers

    PubMed Central

    Collins, Pamela Y.

    2009-01-01

    Mental health services in South Africa increasingly feel the brunt of the AIDS epidemic. Despite the high prevalence of infection in the psychiatric setting, HIV risk reduction interventions targeting South Africans with psychiatric illness remain few and far between. The attitudes of mental health care providers about sexual relations and HIV among people with mental illness continue to influence the extent to which these issues are addressed in care settings. This study examines these attitudes through the use of a semi-structured interview administered to 46 mental health care providers in four provinces of South Africa. I found that personal, contextual and political factors in the clinic and the hospital create barriers to integrating prevention activities. In particular, providers face at least three challenges to intervening in the epidemic among their patients: their own views of psychiatric illness, the transitions occurring in the mental health care system, and shifting social attitudes toward sexuality. Barriers operate at the individual level, the institutional level, and the societal level. At the individual level providers’ perceptions of psychiatric symptoms shape their outlook on intervention with psychiatric patients. At the institutional level disruptive transitions in service delivery relegate HIV services to lesser importance. At the societal level, personal beliefs about sexuality and mental illness have remained slow to change despite major political changes. Minimizing barriers to implementing HIV prevention services requires institutional and health care policies that ensure adequate resources for treating people with mental illness and for staff development and support. PMID:16647793

  7. Standard Setting Lessons Learned in the South African Context: Implications for International Implementation

    ERIC Educational Resources Information Center

    Pitoniak, Mary J.; Yeld, Nan

    2013-01-01

    Criterion-referenced assessments have become more common around the world, with performance standards being set to differentiate different levels of student performance. However, use of standard setting methods developed in the United States may be complicated by factors related to the political and educational contexts within another country. In…

  8. Evaluation of Giant African Pouched Rats for Detection of Pulmonary Tuberculosis in Patients from a High-Endemic Setting

    PubMed Central

    Reither, Klaus; Jugheli, Levan; Glass, Tracy R.; Sasamalo, Mohamed; Mhimbira, Francis A.; Weetjens, Bart J.; Cox, Christophe; Edwards, Timothy L.; Mulder, Christiaan; Beyene, Negussie W.; Mahoney, Amanda

    2015-01-01

    Background This study established evidence about the diagnostic performance of trained giant African pouched rats for detecting Mycobacterium tuberculosis in sputum of well-characterised patients with presumptive tuberculosis (TB) in a high-burden setting. Methods The TB detection rats were evaluated using sputum samples of patients with presumptive TB enrolled in two prospective cohort studies in Bagamoyo, Tanzania. The patients were characterised by sputum smear microscopy and culture, including subsequent antigen or molecular confirmation of Mycobacterium tuberculosis, and by clinical data at enrolment and for at least 5-months of follow-up to determine the reference standard. Seven trained giant African pouched rats were used for the detection of TB in the sputum samples after shipment to the APOPO project in Morogoro, Tanzania. Results Of 469 eligible patients, 109 (23.2%) were culture-positive for Mycobacterium tuberculosis and 128 (27.3%) were non-TB controls with sustained recovery after 5 months without anti-TB treatment. The HIV prevalence was 46%. The area under the receiver operating characteristic curve of the seven rats for the detection of culture-positive pulmonary tuberculosis was 0.72 (95% CI 0.66–0.78). An optimal threshold could be defined at ≥2 indications by rats in either sample with a corresponding sensitivity of 56.9% (95% CI 47.0–66.3), specificity of 80.5% (95% CI 72.5–86.9), positive and negative predictive value of 71.3% (95% CI 60.6–80.5) and 68.7% (95% CI 60.6–76.0), and an accuracy for TB diagnosis of 69.6%. The diagnostic performance was negatively influenced by low burden of bacilli, and independent of the HIV status. Conclusion Giant African pouched rats have potential for detection of tuberculosis in sputum samples. However, the diagnostic performance characteristics of TB detection rats do not currently meet the requirements for high-priority, rapid sputum-based TB diagnostics as defined by the World Health

  9. Biopsychosocial Correlates of Binge Eating Disorder in Caucasian and African American Women with Obesity in Primary Care Settings.

    PubMed

    Udo, Tomoko; White, Marney A; Lydecker, Janet L; Barnes, Rachel D; Genao, Inginia; Garcia, Rina; Masheb, Robin M; Grilo, Carlos M

    2016-05-01

    This study examined racial differences in eating-disorder psychopathology, eating/weight-related histories, and biopsychosocial correlates in women (n = 53 Caucasian and n = 56 African American) with comorbid binge eating disorder (BED) and obesity seeking treatment in primary care settings. Caucasians reported significantly earlier onset of binge eating, dieting, and overweight, and greater number of times dieting than African American. The rate of metabolic syndrome did not differ by race. Caucasians had significantly elevated triglycerides whereas African Americans showed poorer glycaemic control (higher glycated haemoglobin A1c [HbA1c]), and significantly higher diastolic blood pressure. There were no significant racial differences in features of eating disorders, depressive symptoms, or mental and physical health functioning. The clinical presentation of eating-disorder psychopathology and associated psychosocial functioning differed little by race among obese women with BED seeking treatment in primary care settings. Clinicians should assess for and institute appropriate interventions for comorbid BED and obesity in both African American and Caucasian patients. PMID:26640009

  10. African Traditional Education: A Method of Dissseminating Cultural Values.

    ERIC Educational Resources Information Center

    Boateng, Felix

    1983-01-01

    Describes how the philosophical foundations of traditional African education, including oral literature, secret societies and other religious practices, served as a vehicle for intergenerational communication. Warns educational planners in contemporary Africa that a rejection of African heritage will create confusion, loss of identity, and a break…

  11. A review of hypoglycaemia in a South African family practice setting

    PubMed Central

    Ross, Andrew J.; Campbell, Laura

    2016-01-01

    Background The prevalence and incidence of diabetes in South Africa are high and are expected to increase. Mortality and morbidity may be related to hypoglycaemia, and there is limited information on hypoglycaemia from private practice sites. The aim of this study was to assess patients’ education about, knowledge of and response to hypoglycaemia. Methods The study site was a general practice, and participants were all patients with diabetes who presented to the practice over a 1-month period. Data were collected using a closed-ended questionnaire and analysed descriptively. Findings Most respondents were South Africans of Indian origin and were diagnosed with diabetes at a relatively young age. Despite attending a private practice, most had low incomes and low schooling levels. Just under half reported having experienced hypoglycaemia, and there was a strong association between hypoglycaemia and insulin use. Many reported never having received any education around hypoglycaemia. Discussion The study highlights the need for early screening for diabetes in this vulnerable population. Hypoglycaemic education should consider low schooling levels even in a private general practice, and further study is required on the quality and frequency of education provided in general practice. PMID:27380790

  12. Harvest Health: Translation of the Chronic Disease Self-Management Program for Older African Americans in a Senior Setting

    ERIC Educational Resources Information Center

    Gitlin, Laura N.; Chernett, Nancy L.; Harris, Lynn Fields; Palmer, Delores; Hopkins, Paul; Dennis, Marie P.

    2008-01-01

    Purpose: We describe the translation of K. R. Lorig and colleagues' Chronic Disease Self-Management Program (CDSMP) for delivery in a senior center and evaluate pre-post benefits for African American participants. Design and Methods: Modifications to the CDSMP included a name change; an additional introductory session; and course augmentations…

  13. Setting Performance Standards: Concepts, Methods, and Perspectives [Book Review].

    ERIC Educational Resources Information Center

    Thum, Yeow Meng

    2003-01-01

    This volume lays out the essential arguments for the need for standard setting in educational assessment, discusses standard-setting methods and applications, and reviews current issues in standard setting, including legal challenges. (SLD)

  14. The Bookmark Standard-Setting Method: A Literature Review

    ERIC Educational Resources Information Center

    Karantonis, Ana; Sireci, Stephen G.

    2006-01-01

    The Bookmark method for setting standards on educational tests is currently one of the most popular standard-setting methods. However, research to support the method is scarce. In this report, we review the published and unpublished literature on this method as well as some seminal work in the area of evaluating standard-setting studies. Our…

  15. Does Geographic Setting Alter the Roles of Academically Supportive Factors? African American Adolescents' Friendships, Math Self-Concept, and Math Performance

    ERIC Educational Resources Information Center

    Jones, Martin H.; Irvin, Matthew J.; Kibe, Grace W.

    2012-01-01

    The study is one of few to examine how living in rural, suburban, or urban settings may alter factors supporting African Americans adolescents' math performance. The study examines the relationship of math self-concept and perceptions of friends' academic behaviors to African American students' math performance. Participants (N = 1,049) are…

  16. [Surgical treatment of priapism: experience of 56 cases in an African setting].

    PubMed

    Falandry, L; Berlizot, P; Fournier, R; Mechali, P; Thuret, R; Palascak, R; Houlgatte, A

    2000-01-01

    Since priapism is uncommon, treatment is controversial and difficult. In this article we describe a practical, well-documented approach for management of priapism in countries with a high incidence of sickle cell disease. This approach is based on our experience including a total of 56 black patients (49 adults and 7 children) as well as on the results reported in the literature. The patients in our series were examined and treated by the same physician over an 18 year period in various African countries, i.e., Burkina (n = 8), Chad (n = 12), Gabon (n = 19), and Niger (n = 17). Etiologies and pathophysiology are reviewed. In all cases, surgical treatment involved diversion from corpora cavernosa. In the 51 cases with follow-up periods of 3 months or longer, results were considered as excellent in 17 cases (33 p. 100), partial in 5 (9.8 p. 100), and unsuccessful in 29 (56.8). Since 1984, needle drainage with a unilateral transglandular cavernosal-spongiosum shunt based on the technique described by Al Ghorab's has led to better results with immediate detumescence in 80 p. 100 of cases and a long-term success rate of 52 p. 100 (13/25 cases with sufficient follow-up). Except in cases involving sickle cell anemia in which concomitant medical treatment of priapism can be useful, immediate surgical treatment is the only technique effective in avoiding secondary impotence, which was common in our series (58.6). Our p. 100 needle drainage technique appears to be the method of choice for simplified achievement of a unilateral transglandular cavernosal-spongiosum shunt. PMID:10989793

  17. White Student Attitudes about African American Students in a University Setting. Research Report #9-90.

    ERIC Educational Resources Information Center

    Molla, Bekele; Westbrook, Franklin D.

    This report presents the results of a study that compared the attitudes of White university students toward African American students and discusses their perceptions about the classroom and campus environments. The study revealed that White students who had shared a dormitory room with a person of a different racial group and evaluated the…

  18. Closing the Achievement Gap between African American Children and their Caucasians Counterparts Using Collaboration Learning Setting

    ERIC Educational Resources Information Center

    Mubenga, Pascal T.

    2006-01-01

    The underachievement of a large and growing scale of African American children is nothing short of national crisis, according to Haycock (2001) in her research on closing the achievement gap. Haycock indicates that by the year 2010, Black and Hispanics will compromise approximately fifty percent of the school population. This is an alarming…

  19. Speaking up for African American English: Equity and Inclusion in Early Childhood Settings

    ERIC Educational Resources Information Center

    Beneke, Margaret; Cheatham, Gregory A.

    2015-01-01

    A large percentage of young children entering preschool are English speakers who speak a language variety that often differs from the English dialect expected by educators within early childhood programs. While African American English (AAE) is one of the most widely recognized English dialects in the United States, the use of AAE in schools and…

  20. The Relationship between Creativity and Mental Disorder in an African Setting***

    PubMed Central

    Olugbile, O.; Zachariah, M.P.

    2011-01-01

    Background: There has for some time now been recognition that there was a relationship between exceptional creative talent and mental disorder. The works of Andreasen (2008) and others in this area have been very significant. However, most of the research has been carried out in USA and Europe. Very little has come out of Africa on the subject. Aim: To survey the beliefs of different groups within an African society, concerning the possibility of a relationship between creative talent and mental disorder. To assess creativity within a community of people with a formal diagnosis of mental disorder. Materials and Methods: Some of the mythology of the Yoruba was examined for content, concerning the behaviour of certain notable individuals and the existence of psychopathology based on modern-day criteria. The beliefs of members of the general public and mental health professionals concerning the existence of a relationship between creative talent and psychopathology were surveyed using a questionnaire designed for the project. A sample of patients with formal diagnoses of affective disorder or schizophrenia drawn from two units, the Lagos State University Teaching Hospital and the Federal Neuropsychiatric Hospital Yaba, were assessed for ‘Creativity.’ Results Although there are notable ‘eccentric’ figures in local mythology, the overwhelming majority of the people surveyed do not believe there is any relationship between creativity and mental illness. They however believe that engaging in creative activities helps the mentally ill to recover from illness. The mental health professionals, who were clinical psychologists and psychiatrists, had a significant minority who believed that a relationship does exist, and they also strongly assert that creative activity has a therapeutic effect for the mentally ill. A survey of in-patients diagnosed with schizophrenia and affective disorder failed to show a significant difference in the creativity of the two populations

  1. A Preliminary Investigation of the Direct Standard Setting Method.

    ERIC Educational Resources Information Center

    Jones, J. Patrick; And Others

    Three studies assessed the psychometric characteristics of the Direct Standard Setting Method (DSSM). The Angoff technique was also used in each study. The DSSM requires judges to consider an examination 10 items at a time and determine the minimum items in that set a candidate should answer correctly to receive the credential. Nine judges set a…

  2. Revealing the Micro-scale Signature of Endemic Zoonotic Disease Transmission in an African Urban Setting.

    PubMed

    Bourhy, Hervé; Nakouné, Emmanuel; Hall, Matthew; Nouvellet, Pierre; Lepelletier, Anthony; Talbi, Chiraz; Watier, Laurence; Holmes, Edward C; Cauchemez, Simon; Lemey, Philippe; Donnelly, Christl A; Rambaut, Andrew

    2016-04-01

    The development of novel approaches that combine epidemiological and genomic data provides new opportunities to reveal the spatiotemporal dynamics of infectious diseases and determine the processes responsible for their spread and maintenance. Taking advantage of detailed epidemiological time series and viral sequence data from more than 20 years reported by the National Reference Centre for Rabies of Bangui, the capital city of Central African Republic, we used a combination of mathematical modeling and phylogenetic analysis to determine the spatiotemporal dynamics of rabies in domestic dogs as well as the frequency of extinction and introduction events in an African city. We show that although dog rabies virus (RABV) appears to be endemic in Bangui, its epidemiology is in fact shaped by the regular extinction of local chains of transmission coupled with the introduction of new lineages, generating successive waves of spread. Notably, the effective reproduction number during each wave was rarely above the critical value of 1, such that rabies is not self-sustaining in Bangui. In turn, this suggests that rabies at local geographic scales is driven by human-mediated dispersal of RABV among sparsely connected peri-urban and rural areas as opposed to dispersion in a relatively large homogenous urban dog population. This combined epidemiological and genomic approach enables development of a comprehensive framework for understanding disease persistence and informing control measures, indicating that control measures are probably best targeted towards areas neighbouring the city that appear as the source of frequent incursions seeding outbreaks in Bangui. PMID:27058957

  3. Revealing the Micro-scale Signature of Endemic Zoonotic Disease Transmission in an African Urban Setting

    PubMed Central

    Bourhy, Hervé; Nakouné, Emmanuel; Hall, Matthew; Nouvellet, Pierre; Lepelletier, Anthony; Talbi, Chiraz; Watier, Laurence; Holmes, Edward C.; Cauchemez, Simon; Lemey, Philippe; Donnelly, Christl A.; Rambaut, Andrew

    2016-01-01

    The development of novel approaches that combine epidemiological and genomic data provides new opportunities to reveal the spatiotemporal dynamics of infectious diseases and determine the processes responsible for their spread and maintenance. Taking advantage of detailed epidemiological time series and viral sequence data from more than 20 years reported by the National Reference Centre for Rabies of Bangui, the capital city of Central African Republic, we used a combination of mathematical modeling and phylogenetic analysis to determine the spatiotemporal dynamics of rabies in domestic dogs as well as the frequency of extinction and introduction events in an African city. We show that although dog rabies virus (RABV) appears to be endemic in Bangui, its epidemiology is in fact shaped by the regular extinction of local chains of transmission coupled with the introduction of new lineages, generating successive waves of spread. Notably, the effective reproduction number during each wave was rarely above the critical value of 1, such that rabies is not self-sustaining in Bangui. In turn, this suggests that rabies at local geographic scales is driven by human-mediated dispersal of RABV among sparsely connected peri-urban and rural areas as opposed to dispersion in a relatively large homogenous urban dog population. This combined epidemiological and genomic approach enables development of a comprehensive framework for understanding disease persistence and informing control measures, indicating that control measures are probably best targeted towards areas neighbouring the city that appear as the source of frequent incursions seeding outbreaks in Bangui. PMID:27058957

  4. Effect of African- and European-American maternal attitudes and limit-setting strategies on children's self-regulation.

    PubMed

    LeCuyer, Elizabeth A; Swanson, Dena P; Cole, Robert; Kitzman, Harriet

    2011-12-01

    The effect of maternal attitudes and limit-setting strategies on children's self-regulation (measured as committed compliance) was compared in 151 African-American (AA) and 108 European-American (EA) mothers and their 3-year-old children. There were no ethnic differences in children's compliance, however ethnicity moderated the relationship between maternal authoritarian attitudes and children's compliance. Higher authoritarian attitudes predicted less children's compliance in the EA sample, but greater compliance in the AA sample. Observational limit-setting data revealed that in both ethnic groups, maternal authoritarian attitudes influenced children's self-regulation through maternal use of lower-power (gentle) verbal strategies, fewer physical strategies, and judicious use of higher-power verbal strategies. The findings indicate that the meaning and purpose of authoritarian attitudes varies across these mothers' socio-cultural contexts. PMID:21928396

  5. Pain Management for Older African Americans in the Perianesthesia Setting: The "Eight I's".

    PubMed

    Booker, Staja S; Herr, Keela A

    2015-06-01

    National legislation (Affordable Care Act) emphasizes quality and equitable pain care for all patient populations, but frequently, pain management is not effective and equitable in African American (AA) elders, placing them at higher risk for severe pain and persistent pain. Research shows that AAs are less likely to receive guideline-based pain care. This underscores the need for perianesthesia nurses to be knowledgeable and capable of integrating cultural practices and evidence-based recommendations into their care of older AAs to ensure adequate pain management in this vulnerable population. This article describes differences and disparities in pain management in AA older adults and provides a cultural framework to guide perianesthesia pain management. PMID:26003763

  6. Measuring Men's Gender Norms and Gender Role Conflict/Stress in a High HIV-Prevalence South African Setting.

    PubMed

    Gottert, Ann; Barrington, Clare; Pettifor, Audrey; McNaughton-Reyes, Heath Luz; Maman, Suzanne; MacPhail, Catherine; Kahn, Kathleen; Selin, Amanda; Twine, Rhian; Lippman, Sheri A

    2016-08-01

    Gender norms and gender role conflict/stress may influence HIV risk behaviors among men; however scales measuring these constructs need further development and evaluation in African settings. We conducted exploratory and confirmatory factor analyses to evaluate the Gender Equitable Men's Scale (GEMS) and the Gender Role Conflict/Stress (GRC/S) scale among 581 men in rural northeast South Africa. The final 17-item GEMS was unidimensional, with adequate model fit and reliability (alpha = 0.79). Factor loadings were low (0.2-0.3) for items related to violence and sexual relationships. The final 24-item GRC/S scale was multidimensional with four factors: Success, power, competition; Subordination to women; Restrictive emotionality; and Sexual prowess. The scale had adequate model fit and good reliability (alpha = 0.83). While GEMS is a good measure of inequitable gender norms, new or revised scale items may need to be explored in the South African context. Adding the GRC/S scale to capture men's strain related to gender roles could provide important insights into men's risk behaviors. PMID:27209467

  7. How Good Is Good Enough? Educational Standard Setting and Its Effect on African American Test Takers

    ERIC Educational Resources Information Center

    Caines, Jade; Engelhard, George, Jr.

    2012-01-01

    Standard setting (the process of establishing minimum passing scores on high-stakes exams) is a highly evaluative and policy-driven process. It is a common belief that standard setting panels should be diverse and representative. There is concern, however, that panelists with varying characteristics may differentially influence the results of the…

  8. Bi-directional evolutionary level set method for topology optimization

    NASA Astrophysics Data System (ADS)

    Zhu, Benliang; Zhang, Xianmin; Fatikow, Sergej; Wang, Nianfeng

    2015-03-01

    A bi-directional evolutionary level set method for solving topology optimization problems is presented in this article. The proposed method has three main advantages over the standard level set method. First, new holes can be automatically generated in the design domain during the optimization process. Second, the dependency of the obtained optimized configurations upon the initial configurations is eliminated. Optimized configurations can be obtained even being started from a minimum possible initial guess. Third, the method can be easily implemented and is computationally more efficient. The validity of the proposed method is tested on the mean compliance minimization problem and the compliant mechanisms topology optimization problem.

  9. Installation of Ceramic Tile: Residential Thin-Set Methods.

    ERIC Educational Resources Information Center

    Short, Sam

    This curriculum guide contains materials for use in teaching a course on residential thin-set methods of tile installation. Covered in the individual units are the following topics: the tile industry; basic math; tools; measurement; safety in tile setting; installation materials and guidelines for their use; floors; counter tops and backsplashes;…

  10. An Analysis of Teacher Perceptions of African American Boys' Educational Status in a Rural School Setting

    ERIC Educational Resources Information Center

    Bruton, Chantrell Anita

    2012-01-01

    African American boys are the lowest achieving academic group in public schools. Current research has delved into why this occurs and into implications for African American boys and communities. However, current research has focused on this in urban populations and has not looked at length at the status of African American boys in rural…

  11. An efficient MRF embedded level set method for image segmentation.

    PubMed

    Yang, Xi; Gao, Xinbo; Tao, Dacheng; Li, Xuelong; Li, Jie

    2015-01-01

    This paper presents a fast and robust level set method for image segmentation. To enhance the robustness against noise, we embed a Markov random field (MRF) energy function to the conventional level set energy function. This MRF energy function builds the correlation of a pixel with its neighbors and encourages them to fall into the same region. To obtain a fast implementation of the MRF embedded level set model, we explore algebraic multigrid (AMG) and sparse field method (SFM) to increase the time step and decrease the computation domain, respectively. Both AMG and SFM can be conducted in a parallel fashion, which facilitates the processing of our method for big image databases. By comparing the proposed fast and robust level set method with the standard level set method and its popular variants on noisy synthetic images, synthetic aperture radar (SAR) images, medical images, and natural images, we comprehensively demonstrate the new method is robust against various kinds of noises. In particular, the new level set method can segment an image of size 500 × 500 within 3 s on MATLAB R2010b installed in a computer with 3.30-GHz CPU and 4-GB memory. PMID:25420261

  12. Attitudes Toward Contraceptive Methods Among African American Men and Women: Similarities and Differences

    PubMed Central

    Thorburn, Sheryl

    2007-01-01

    Purpose Men’s attitudes toward contraceptives are an understudied area, even though many men participate in contraceptive decision-making. The purpose of this study was to examine attitudes and perceptions regarding a selection of contraceptive methods among a national sample of African Americans, with a particular focus on gender differences. Methods Data come from a telephone survey of African Americans (aged 15–44 years) living in the contiguous U.S. For the present analyses, the sample was restricted to 152 men and 281 women who reported having had a sexual partner of the opposite gender at some point in their lives. Bivariate analyses compared men and women’s ratings of birth control pills, male condoms, female condoms, Norplant, Depo Provera, female sterilization, and male sterilization along several dimensions: bad/good, harmful/beneficial, difficult/easy, dangerous/safe, immoral/moral, and effectiveness. Multiple logistic regressions were performed to determine the association between gender and contraceptive attitudes, adjusting for sociodemographic variables. Results Male condoms were given the most favorable ratings along most dimensions by both African American men and women. In general, ratings of male condoms, female condoms, and Norplant did not significantly differ by gender. African American men did, however, give female and male sterilization, birth control pills, and Depo Provera significantly poorer ratings than did African American women. Conclusion African American men had less favorable evaluations of some contraceptive methods than did African American women. Further research is needed to examine how such gender differences may play a role in contraceptive decisions. PMID:17321945

  13. A Comparative Study of Standard-Setting Methods.

    ERIC Educational Resources Information Center

    Livingston, Samuel A.; Zieky, Michael J.

    1989-01-01

    The borderline group standard-setting method (BGSM), Nedelsky method (NM), and Angoff method (AM) were compared, using reading scores for 1,948 and mathematics scores for 2,191 sixth through ninth graders. The NM and AM were inconsistent with the BGSM. Passing scores were higher where students were more able. (SLD)

  14. A Comparison of Angoff and Bookmark Standard Setting Methods.

    ERIC Educational Resources Information Center

    Buckendahl, Chad W.; Smith, Russell W.; Impara, James C.; Plake, Barbara S.

    2002-01-01

    Compared simplified variations on the Angoff and Bookmark methods for setting cut scores on educational assessments with data from a grade 7 mathematics test (23 panelists in all). Although the Angoff method is more widely used, results show that the Bookmark method has some promising features. (SLD)

  15. A Comparison of Bookmark and Angoff Standard Setting Methods

    ERIC Educational Resources Information Center

    Çetin, Sevda; Gelbal, Selahattin

    2013-01-01

    In this research, the cut score of a foundation university was re-calculated with bookmark method and with Angoff method, each of which is a standard setting method; and the cut scores found were compared with the current proficiency score. Thus, the final cut score was found to be 27.87 with the cooperative work of 17 experts through the Angoff…

  16. Integration of non-communicable diseases in health care: tackling the double burden of disease in African settings

    PubMed Central

    Temu, Florence; Leonhardt, Marcus; Carter, Jane; Thiam, Sylla

    2014-01-01

    Sub-Saharan African countries now face the double burden of Non Communicable and Communicable Diseases. This situation represents a major threat to fragile health systems and emphasises the need for innovative integrative approaches to health care delivery. Health services need to be reorganised to address populations’ needs holistically and effectively leverage resources in already resource-limited settings. Access and delivery of quality health care should be reinforced and implemented at primary health care level within the framework of health system strengthening. Competencies need to be developed around services provided rather than specific diseases. New models of integration within the health sector and other sectors should be explored and further evidence generated to inform policy and practice to combat the double burden. PMID:25419329

  17. Experiences and effects of psychiatric stigma: Monologues of the stigmatizers and the stigmatized in an African setting

    PubMed Central

    Egbe, Catherine O.

    2015-01-01

    People with mental illness (PWMI) are faced with a number of social and health-related challenges especially stigma and discrimination which tend to have negative effects on their lives. This paper presents narrative monologues portraying the experiences and effects of psychiatric stigma and discrimination on PWMI in South Africa. These narratives voice out the concerns of the stigmatizers (specifically family members and significant others of PWMI) and the stigmatized in a poetic fashion. The society is still not very sympathetic to the plights of PWMI and this affects their general health and well-being. Traditional beliefs and prejudice still drive public attitude towards PWMI especially in African settings. These narratives presented in a poetic fashion in this paper highlight some salient issues relating to the experience and effects of stigma and the desires of PWMI to be treated with love and respect and helped to lead healthy normal lives. PMID:26088367

  18. Experiences and effects of psychiatric stigma: Monologues of the stigmatizers and the stigmatized in an African setting.

    PubMed

    Egbe, Catherine O

    2015-01-01

    People with mental illness (PWMI) are faced with a number of social and health-related challenges especially stigma and discrimination which tend to have negative effects on their lives. This paper presents narrative monologues portraying the experiences and effects of psychiatric stigma and discrimination on PWMI in South Africa. These narratives voice out the concerns of the stigmatizers (specifically family members and significant others of PWMI) and the stigmatized in a poetic fashion. The society is still not very sympathetic to the plights of PWMI and this affects their general health and well-being. Traditional beliefs and prejudice still drive public attitude towards PWMI especially in African settings. These narratives presented in a poetic fashion in this paper highlight some salient issues relating to the experience and effects of stigma and the desires of PWMI to be treated with love and respect and helped to lead healthy normal lives. PMID:26088367

  19. Fuzzy Set Methods for Object Recognition in Space Applications

    NASA Technical Reports Server (NTRS)

    Keller, James M. (Editor)

    1992-01-01

    Progress on the following four tasks is described: (1) fuzzy set based decision methodologies; (2) membership calculation; (3) clustering methods (including derivation of pose estimation parameters), and (4) acquisition of images and testing of algorithms.

  20. Quick-setting concrete and a method for making quick-setting concrete

    DOEpatents

    Wagh, Arun S.; Singh, Dileep; Pullockaran, Jose D.; Knox, Lerry

    1997-01-01

    A method for producing quick setting concrete is provided comprising hydrng a concrete dry mixture with carbonate solution to create a slurry, and allowing the slurry to cure. The invention also provides for a quick setting concrete having a predetermined proportion of CaCO.sub.3 of between 5 and 23 weight percent of the entire concrete mixture, and whereby the concrete has a compression strength of approximately 4,000 pounds per square inch (psi) within 24 hours after pouring.

  1. Children's Digital Literacy Practices in Unequal South African Settings

    ERIC Educational Resources Information Center

    Lemphane, Polo; Prinsloo, Mastin

    2014-01-01

    Contemporary movements of people and resources across rural and urban settings, city locales and national and regional borders produce challenges for familiar ways of studying languages as located and stable systems and of literacies as standardised ways of reading and writing texts. This study contrasts children's digital communicative…

  2. Stereotype Threat in Manual Labor Settings for African American and Caucasian Participants

    ERIC Educational Resources Information Center

    Flanagan, Jennifer L.; Green, Raymond J.

    2011-01-01

    Stereotype threat has primarily been studied with regard to test performance in academic settings, testing aptitude, ability, and intelligence, and it has been found to cause both behavioral and cognitive decrements. Although there is research on stereotype threat in the workplace, this too is usually conducted in upper-level or more academically…

  3. A 3D Level Set Method for Microwave Breast Imaging

    PubMed Central

    Colgan, Timothy J.; Hagness, Susan C.; Van Veen, Barry D.

    2015-01-01

    Objective Conventional inverse-scattering algorithms for microwave breast imaging result in moderate resolution images with blurred boundaries between tissues. Recent 2D numerical microwave imaging studies demonstrate that the use of a level set method preserves dielectric boundaries, resulting in a more accurate, higher resolution reconstruction of the dielectric properties distribution. Previously proposed level set algorithms are computationally expensive and thus impractical in 3D. In this paper we present a computationally tractable 3D microwave imaging algorithm based on level sets. Methods We reduce the computational cost of the level set method using a Jacobian matrix, rather than an adjoint method, to calculate Frechet derivatives. We demonstrate the feasibility of 3D imaging using simulated array measurements from 3D numerical breast phantoms. We evaluate performance by comparing full 3D reconstructions to those from a conventional microwave imaging technique. We also quantitatively assess the efficacy of our algorithm in evaluating breast density. Results Our reconstructions of 3D numerical breast phantoms improve upon those of a conventional microwave imaging technique. The density estimates from our level set algorithm are more accurate than those of conventional microwave imaging, and the accuracy is greater than that reported for mammographic density estimation. Conclusion Our level set method leads to a feasible level of computational complexity for full 3D imaging, and reconstructs the heterogeneous dielectric properties distribution of the breast more accurately than conventional microwave imaging methods. Significance 3D microwave breast imaging using a level set method is a promising low-cost, non-ionizing alternative to current breast imaging techniques. PMID:26011863

  4. A PDE-Based Fast Local Level Set Method

    NASA Astrophysics Data System (ADS)

    Peng, Danping; Merriman, Barry; Osher, Stanley; Zhao, Hongkai; Kang, Myungjoo

    1999-11-01

    We develop a fast method to localize the level set method of Osher and Sethian (1988, J. Comput. Phys.79, 12) and address two important issues that are intrinsic to the level set method: (a) how to extend a quantity that is given only on the interface to a neighborhood of the interface; (b) how to reset the level set function to be a signed distance function to the interface efficiently without appreciably moving the interface. This fast local level set method reduces the computational effort by one order of magnitude, works in as much generality as the original one, and is conceptually simple and easy to implement. Our approach differs from previous related works in that we extract all the information needed from the level set function (or functions in multiphase flow) and do not need to find explicitly the location of the interface in the space domain. The complexity of our method to do tasks such as extension and distance reinitialization is O(N), where N is the number of points in space, not O(N log N) as in works by Sethian (1996, Proc. Nat. Acad. Sci. 93, 1591) and Helmsen and co-workers (1996, SPIE Microlithography IX, p. 253). This complexity estimation is also valid for quite general geometrically based front motion for our localized method.

  5. Barriers to condom use and barrier method preferences among low-income African-American women.

    PubMed

    Eldridge, G D; St Lawrence, J S; Little, C E; Shelby, M C; Brasfield, T L

    1995-01-01

    Low-income African-American women (N = 178) entering health clinics completed surveys assessing perceived barriers to condom use for themselves personally and for African-American women generally. Following the survey, each woman received a demonstration of five barrier contraceptive methods and then rated her preference among those methods. The women perceived relatively few personal barriers to use of the male condom but perceived significantly greater barriers for other African-American women (all p < .0001). The male condom was first choice of the largest percentage of women (45%) and last choice of the smallest percentage of women (11%). The male condom was preferred for its convenience, availability, and safety, although the necessity for active cooperation by the male partner was considered a hindrance to using the method. Only 23% of women ranked the female condom as first choice and 35% ranked the female condom as last choice. Reasons for selecting the female condom included preference for a female-controlled method, safety, and protection. However, the female condom was perceived to be uncomfortable, to require the partner's acquiescence, and to interfere with sexual experience. Differences in the women's perceptions of barriers to condom use for themselves and for other African-American women are consistent with Weinstein's theory of optimistic bias. Preferences among barrier methods indicate that further research and product development are needed to develop barrier methods that are female-controlled, do not require the awareness of the male partner, and are safe, comfortable, and convenient. PMID:7483652

  6. Total variation and level set methods in image science

    NASA Astrophysics Data System (ADS)

    Tsai, Yen-Hsi Richard; Osher, Stanley

    We review level set methods and the related techniques that are common in many PDE-based image models. Many of these techniques involve minimizing the total variation of the solution and admit regularizations on the curvature of its level sets. We examine the scope of these techniques in image science, in particular in image segmentation, interpolation, and decomposition, and introduce some relevant level set techniques that are useful for this class of applications. Many of the standard problems are formulated as variational models. We observe increasing synergistic progression of new tools and ideas between the inverse problem community and the `imagers'. We show that image science demands multi-disciplinary knowledge and flexible, but still robust methods. That is why the level set method and total variation methods have become thriving techniques in this field.Our goal is to survey recently developed techniques in various fields of research that are relevant to diverse objectives in image science. We begin by reviewing some typical PDE-based applications in image processing. In typical PDE methods, images are assumed to be continuous functions sampled on a grid. We will show that these methods all share a common feature, which is the emphasis on processing the level lines of the underlying image. The importance of level lines has been known for some time. See, e.g., Alvarez, Guichard, Morel and Lions (1993). This feature places our slightly general definition of the level set method for image science in context. In Section 2 we describe the building blocks of a typical level set method in the continuum setting. Each important task that we need to do is formulated as the solution to certain PDEs. Then, in Section 3, we briefly describe the finite difference methods developed to construct approximate solutions to these PDEs. Some approaches to interpolation into small subdomains of an image are reviewed in Section 4. In Section 5 we describe the Chan

  7. Professionals' Perceptions about the Need for Pain Management Interventions for Children with Cerebral Palsy in South African School Settings.

    PubMed

    Nilsson, Stefan; Johnson, Ensa; Adolfsson, Margareta

    2016-08-01

    Pain is common in children with cerebral palsy (CP) and may have negative consequences for children's success in their studies. Research has shown that pain in childhood negatively influences individuals' participation and quality of life in later years. This study investigated how professionals in South African school settings respond to children's need for pain management in an attempt to enable the children to be active participants in school activities, despite their pain. The study was descriptive and followed a qualitative design (i.e., focus group interviews with semistructured questions and a conventional content analysis). Five government schools for children with special education needs in South Africa's Gauteng province participated. Participants/Subjects: Thirty-eight professionals who represented eight professions. Professional statements on the topic were collected from five focus group sessions conducted during one week. Qualitative content analysis of the data was performed. Similar statements were combined, coded, and sorted into main categories and subcategories. The analysis identified three main categories for pain management: environmental, treatment, and support strategies. In addition, four groups of statements emerged on how contextual factors might affect pain in children with CP and their participation in school settings. It is important to train professionals in pain management and to implement structured models for pain prevention and management to ensure that best practices are adhered to for children with CP who suffer from acute or chronic pain. PMID:27349380

  8. Assessment of gene set analysis methods based on microarray data.

    PubMed

    Alavi-Majd, Hamid; Khodakarim, Soheila; Zayeri, Farid; Rezaei-Tavirani, Mostafa; Tabatabaei, Seyyed Mohammad; Heydarpour-Meymeh, Maryam

    2014-01-25

    Gene set analysis (GSA) incorporates biological information into statistical knowledge to identify gene sets differently expressed between two or more phenotypes. It allows us to gain an insight into the functional working mechanism of cells beyond the detection of differently expressed gene sets. In order to evaluate the competence of GSA approaches, three self-contained GSA approaches with different statistical methods were chosen; Category, Globaltest and Hotelling's T(2) together with their assayed power to identify the differences expressed via simulation and real microarray data. The Category does not take care of the correlation structure, while the other two deal with correlations. In order to perform these methods, R and Bioconductor were used. Furthermore, venous thromboembolism and acute lymphoblastic leukemia microarray data were applied. The results of three GSAs showed that the competence of these methods depends on the distribution of gene expression in a dataset. It is very important to assay the distribution of gene expression data before choosing the GSA method to identify gene sets differently expressed between phenotypes. On the other hand, assessment of common genes among significant gene sets indicated that there was a significant agreement between the result of GSA and the findings of biologists. PMID:24012817

  9. The Augmented Fast Marching Method for Level Set Reinitialization

    NASA Astrophysics Data System (ADS)

    Salac, David

    2011-11-01

    The modeling of multiphase fluid flows typically requires accurate descriptions of the interface and curvature of the interface. Here a new reinitialization technique based on the fast marching method for gradient-augmented level sets is presented. The method is explained and results in both 2D and 3D are presented. Overall the method is more accurate than reinitialization methods based on similar stencils and the resulting curvature fields are much smoother. The method will also be demonstrated in a sample application investigating the dynamic behavior of vesicles in general fluid flows. Support provided by University at Buffalo - SUNY.

  10. Quick-setting concrete and a method for making quick-setting concrete

    DOEpatents

    Wagh, A.S.; Singh, D.; Pullockaran, J.D.; Knox, L.

    1997-04-29

    A method for producing quick setting concrete is provided comprising mixing a concrete dry mixture with carbonate solution to create a slurry, and allowing the slurry to cure. The invention also provides for a quick setting concrete having a predetermined proportion of CaCO{sub 3} of between 5 and 23 weight percent of the entire concrete mixture, and whereby the concrete has a compression strength of approximately 4,000 pounds per square inch (psi) within 24 hours after pouring. 2 figs.

  11. Qualitative research: Observational methods in health care settings.

    PubMed Central

    Mays, N.; Pope, C.

    1995-01-01

    Clinicians used to observing individual patients, and epidemiologists trained to observe the course of disease, may be forgiven for misunderstanding the term observational method as used in qualitative research. In contrast to the clinician or epidemiologist, the qualitative researcher systematically watches people and events to find out about behaviours and interactions in natural settings. Observation, in this sense, epitomises the idea of the researcher as the research instrument. It involves "going into the field"--describing and analysing what has been seen. In health care settings this method has been insightful and illuminating, but it is not without pitfalls for the unprepared researcher. Images p183-a PMID:7613435

  12. Mapping the African thunderstorm center in absolute units using Schumann resonance spectral decomposition method

    NASA Astrophysics Data System (ADS)

    Dyrda, Michal; Kulak, Andrzej; Mlynarczyk, Janusz

    2015-04-01

    Monitoring of the global lightning activity provides a very useful tool to study the global warming phenomenon and the other longer-scale climate changes induced by humans. The lightning activity is measured using various observational methods form space (optical satellite observations) as well as from the ground mostly by VLF /LF lightning detection networks, i.e. World Wide Lightning Location Network (WWLLN) or lightning detection network (LINET) in Europe. However, the global lightning activity measurements are possible only in the ELF range. Here we examine the African thunderstorm activity center, which is the most violent and active one. In a spherical damped resonator, such as the Earth-ionosphere cavity, the electromagnetic field is described by the solution of an inhomogeneous wave equation. For such equation the general solution can be expressed by the superposition of the solutions of the homogeneous equation, describing the resonance field, and the component, which is quite strong close to the source and weakens with source-observer separation. Thus, the superposition of the standing wave field with the field of traveling waves, which supply the energy from the lighting discharges to the global resonator, is a main reason for an asymmetric shape of the observational Schumann resonance (SR) power spectra, which highly deviate from the Lorentz curves. It is possible to separate this component from the signal using the spectrum decomposition method proposed by Kułak et al. [2006]. In our approach, we apply the inverse problem solution for determining the distance of the dominant lightning source. The distances to the thunderstorm centers are calculated using the analytical models for the electromagnetic waves propagation in the Earth-ionosphere cavity. Such forms of analytic solutions of the resonant field in the spherical cavity is the zonal harmonic series representation, described by Mushtak and Williams [2002] and we calculated the sets of such curves

  13. DEVELOPING AND EXPLOITING A UNIQUE SEISMIC DATA SET FROM SOUTH AFRICAN GOLD MINES FOR SOURCE CHARACTERIZATION AND WAVE PROPAGATION

    SciTech Connect

    Julia, J; Nyblade, A A; Gok, R; Walter, W R; Linzer, L; Durrheim, R

    2008-07-08

    In this project, we are developing and exploiting a unique seismic data set to address the characteristics of small seismic events and the associated seismic signals observed at local (< 200 km) and regional (< 2000 km) distances. The dataset is being developed using mining-induced events from 3 deep gold mines in South Africa recorded on inmine networks (< 1 km) comprised of tens of high-frequency sensors, a network of 4 broadband stations installed as part of this project at the surface around the mines (1-10 km), and a network of existing broadband seismic stations at local/regional distances (50-1000 km) from the mines. After 1 year of seismic monitoring of mine activity (2007), over 10,000 events in the range -3.4 < ML < 4.4 have been catalogued and recorded by the in-mine networks. Events with positive magnitudes are generally well recorded by the surface-mine stations, while magnitudes 3.0 and larger are seen at regional distances (up to {approx}600 km) in high-pass filtered recordings. We have analyzed in-mine recordings in detail at one of the South African mines (Savuka) to (i) improve on reported hypocentral locations, (ii) verify sensor orientations, and (iii) determine full moment tensor solutions. Hypocentral relocations on all catalogued events have been obtained from P- and S-wave travel-times reported by the mine network operator through an automated procedure that selects travel-times falling on Wadati lines with slopes in the 0.6-0.7 range; sensor orientations have been verified and, when possible, corrected by correlating P-, SV-, and SH-waveforms obtained from theoretical and empirical (polarization filter) rotation angles; full moment tensor solutions have been obtained by inverting P-, SV-, and SH- spectral amplitudes measured on the theoretically rotated waveforms with visually assigned polarities. The relocation procedure has revealed that origin times often necessitate a negative correction of a few tenths of second and that hypocentral

  14. A model for selecting assessment methods for evaluating medical students in African medical schools.

    PubMed

    Walubo, Andrew; Burch, Vanessa; Parmar, Paresh; Raidoo, Deshandra; Cassimjee, Mariam; Onia, Rudy; Ofei, Francis

    2003-09-01

    Introduction of more effective and standardized assessment methods for testing students' performance in Africa's medical institutions has been hampered by severe financial and personnel shortages. Nevertheless, some African institutions have recognized the problem and are now revising their medical curricula, and, therefore, their assessment methods. These institutions, and those yet to come, need guidance on selecting assessment methods so as to adopt models that can be sustained locally. The authors provide a model for selecting assessment methods for testing medical students' performance in African medical institutions. The model systematically evaluates factors that influence implementation of an assessment method. Six commonly used methods (the essay examinations, short-answer questions, multiple-choice questions, patient-based clinical examination, problem-based oral examination [POE], and objective structured clinical examination) are evaluated by scoring and weighting against performance, cost, suitability, and safety factors. In the model, the highest score identifies the most appropriate method. Selection of an assessment method is illustrated using two institutional models, one depicting an ideal situation in which the objective structured clinical examination was preferred, and a second depicting the typical African scenario in which the essay and short-answer-question examinations were best. The POE method received the highest score and could be recommended as the most appropriate for Africa's medical institutions, but POE assessments require changing the medical curricula to a problem-based learning approach. The authors' model is easy to understand and promotes change in the medical curriculum and method of student assessment. PMID:14507620

  15. Level set method for image segmentation based on moment competition

    NASA Astrophysics Data System (ADS)

    Min, Hai; Wang, Xiao-Feng; Huang, De-Shuang; Jin, Jing; Wang, Hong-Zhi; Li, Hai

    2015-05-01

    We propose a level set method for image segmentation which introduces the moment competition and weakly supervised information into the energy functional construction. Different from the region-based level set methods which use force competition, the moment competition is adopted to drive the contour evolution. Here, a so-called three-point labeling scheme is proposed to manually label three independent points (weakly supervised information) on the image. Then the intensity differences between the three points and the unlabeled pixels are used to construct the force arms for each image pixel. The corresponding force is generated from the global statistical information of a region-based method and weighted by the force arm. As a result, the moment can be constructed and incorporated into the energy functional to drive the evolving contour to approach the object boundary. In our method, the force arm can take full advantage of the three-point labeling scheme to constrain the moment competition. Additionally, the global statistical information and weakly supervised information are successfully integrated, which makes the proposed method more robust than traditional methods for initial contour placement and parameter setting. Experimental results with performance analysis also show the superiority of the proposed method on segmenting different types of complicated images, such as noisy images, three-phase images, images with intensity inhomogeneity, and texture images.

  16. Optimizing distance-based methods for large data sets

    NASA Astrophysics Data System (ADS)

    Scholl, Tobias; Brenner, Thomas

    2015-10-01

    Distance-based methods for measuring spatial concentration of industries have received an increasing popularity in the spatial econometrics community. However, a limiting factor for using these methods is their computational complexity since both their memory requirements and running times are in {{O}}(n^2). In this paper, we present an algorithm with constant memory requirements and shorter running time, enabling distance-based methods to deal with large data sets. We discuss three recent distance-based methods in spatial econometrics: the D&O-Index by Duranton and Overman (Rev Econ Stud 72(4):1077-1106, 2005), the M-function by Marcon and Puech (J Econ Geogr 10(5):745-762, 2010) and the Cluster-Index by Scholl and Brenner (Reg Stud (ahead-of-print):1-15, 2014). Finally, we present an alternative calculation for the latter index that allows the use of data sets with millions of firms.

  17. A Comparison of the Angoff and Bookmark Standard Setting Methods.

    ERIC Educational Resources Information Center

    Buckendahl, Chad W.; Smith, Russ W.; Impara, James C.; Plake, Barbara S.

    This paper presents a comparison of two commonly used methods, Angoff (W. Angoff, 1971) and Bookmark (D. Lewis, H. Mitzel, and D. Green, 1996), for setting cut scores on selected response tests. This comparison is presented through an application to a grade 7 mathematics assessment in a suburban Midwestern school district. Training and operational…

  18. The Learning Environment and the Reading Achievement of Middle School African American Male Students in a Suburban School Setting

    ERIC Educational Resources Information Center

    Frazier, Nicole Denise

    2012-01-01

    The reading achievement of African American males might be impacted by a host of variables. This study was undertaken to determine if there was a difference in the culturally responsive characteristics present in the learning environment of a middle school and the reading achievement of middle school African American males. The purpose of this…

  19. Illinois Secondary Principals' Perceptions and Expectations Concerning Students Who Use African American Vernacular English in an Academic Setting

    ERIC Educational Resources Information Center

    McClendon, Garrard Overton

    2010-01-01

    This study investigates principals' individual and aggregate perceptions of and expectations for students who use African American Vernacular English. Using the African American English Teacher Attitude Scale (AAETAS), the study seeks to describe the relationship between principals' demographic characteristics and their perceptions of African…

  20. Pattern of chronic myeloid leukemia in the imatinib era in a Sub-Saharan African setting.

    PubMed

    Faye, Blaise Felix; Dieng, Nata; Seck, Moussa; Gadji, Macoura; Gueye, Youssou Bamar; Sy, Diariatou; Toure, Sokhna Aissatou; Sall, Abibatou; Toure, Awa Oumar; Dieye, Tandakha Ndiaye; Diop, Saliou

    2016-10-01

    Chronic myeloid leukemia (CML) is an orphan disease in Africa because of the inaccessibility to specific treatment and the high cost of diagnosis and monitoring patients. The aim of this study was to report CML treatment response in a developing country in the tyrosine kinase inhibitor era. We conducted a longitudinal study of our cohort of CML patients. Socio-demographic, diagnosis, therapeutic, and treatment response parameters were studied. Sokal score, disease phase at diagnosis, delay from diagnosis to treatment, and treatment response were analyzed for their impact on survival. Fifty-five patients with a diagnosis of CML and who received treatment with imatinib for a minimum of 3 months were included in this study. Median follow-up was 170 patient-years. The sex ratio (M/F) was 1.62 and median age at diagnosis was 42 years. At diagnosis, 85.5 % of the patients were in chronic phase (CP), 12.7 % in accelerated phase (AP), and 1.8 % in blast crisis (BC). Sokal risk score distribution was as follows: low risk 29.8 %, intermediate risk 38.3 %, and high risk 31.9 %. Median time from first symptoms to first medical visit was 6.2 months and median time from first medical visit to cytogenetic and or molecular confirmation was 12.4 months. Mean delay time from first medical visit to imatinib initiation was 12.5 months (95 % CI 6.3-18.7). The complete hematologic response (CHR) at 3 months, the major cytogenetic response (MCR) at 12 months, and the major molecular response (MMR) at 24 months were respectively 82.4, 75, and 25 %. The 2-year overall survival rate was 81 %. Advanced phase at the diagnosis, discontinuation of imatinib therapy over 15 % of the time, lack of CHR at 3 months, lack of MCR at 12 months, and progression of the disease during imatinib therapy were associated with a risk of death (p ≤ 0.05). Our data confirm the improved prognosis of CML treated with imatinib in the setting of a developing country. However, response rates

  1. Patterns of Disclosure of HIV- Status to Infected Children in a Sub-Saharan African Setting

    PubMed Central

    Vaz, Lara M. E.; Maman, Suzanne; Eng, Eugenia; Barbarin, Oscar A.; Tshikandu, Tomi; Behets, Frieda

    2011-01-01

    Objective Adult caregivers provide children living with HIV with varying amounts and types of information about their health status that may affect their coping and health care behaviors. We aimed to describe patterns of information-sharing with children and thoughts around disclosure among caregivers in the Democratic Republic of the Congo. Methods 259 primary caregivers of children 5–17 years old in an HIV pediatric care and treatment program were screened; 8 adult caregivers (3%) had informed their child of the child’s HIV status. We conducted structured interviews with 201 caregivers whose children had not yet been told their HIV status. Results Nearly 50% of caregivers provided no information to their child about their health; 15% had given partial information without mentioning HIV, and 33% provided information that deflected attention from HIV, whether deliberately so or otherwise. Almost all caregivers said that the child should be told their status some day, and three-fourths reported having ever thought about what might lead them to tell. However, nearly one-third of caregivers saw no benefits to informing the child of her/his HIV status. A majority of caregivers felt that they themselves were the best to eventually disclose to the child, but some wanted support from health care providers. Conclusion HIV-infected children are given limited information about their health. Health care providers may serve as important sources of support to caregivers as they decide when and how to talk candidly with their children about their health. PMID:21317803

  2. "It's my secret": barriers to paediatric HIV treatment in a poor rural South African setting.

    PubMed

    Kimani-Murage, E W; Manderson, L; Norris, S A; Kahn, K

    2013-01-01

    In South Africa, a third of children born are exposed to HIV, while fewer undergo an HIV confirmatory test. Anti-retroviral therapy (ART) coverage among children remains low-despite roll-out of the national ART programme in South Africa in 2004. This study sought to understand critical barriers to seeking HIV-related care for children in rural South Africa. Data presented in this article derive from community-based qualitative research in poor rural villages in north-east South Africa; this includes 21 in-depth interviews in 2008 among caregivers of children identified as HIV-positive in 2007 from a randomly selected community-based sample. Using NVIVO 8, data were coded and analysed, using a constant comparative method to identify themes and their repetitions and variations. Structural barriers leading to poor access to health care, and social and systems barriers, all influenced paediatric HIV treatment seeking. Of concern was the expressed need to maintain secrecy regarding a child's HIV status to avoid stigma and discrimination, and misconceptions regarding the course of HIV disease in children; this led to a delay in seeking appropriate care. These barriers need to be addressed, including through focused awareness campaigns, improved access to health care and interventions to address rural poverty and development at both household and community levels. In addition, training of health care professionals to improve their attitudes and practice may be necessary. However, this study only provides the perspective of the caregivers; further studies with health care providers are needed to gain a fuller picture for appropriate policy and practice guidance. PMID:23244783

  3. SET: a pupil detection method using sinusoidal approximation.

    PubMed

    Javadi, Amir-Homayoun; Hakimi, Zahra; Barati, Morteza; Walsh, Vincent; Tcheang, Lili

    2015-01-01

    Mobile eye-tracking in external environments remains challenging, despite recent advances in eye-tracking software and hardware engineering. Many current methods fail to deal with the vast range of outdoor lighting conditions and the speed at which these can change. This confines experiments to artificial environments where conditions must be tightly controlled. Additionally, the emergence of low-cost eye tracking devices calls for the development of analysis tools that enable non-technical researchers to process the output of their images. We have developed a fast and accurate method (known as "SET") that is suitable even for natural environments with uncontrolled, dynamic and even extreme lighting conditions. We compared the performance of SET with that of two open-source alternatives by processing two collections of eye images: images of natural outdoor scenes with extreme lighting variations ("Natural"); and images of less challenging indoor scenes ("CASIA-Iris-Thousand"). We show that SET excelled in outdoor conditions and was faster, without significant loss of accuracy, indoors. SET offers a low cost eye-tracking solution, delivering high performance even in challenging outdoor environments. It is offered through an open-source MATLAB toolkit as well as a dynamic-link library ("DLL"), which can be imported into many programming languages including C# and Visual Basic in Windows OS (www.eyegoeyetracker.co.uk). PMID:25914641

  4. Efficient molecular surface generation using level-set methods.

    PubMed

    Can, Tolga; Chen, Chao-I; Wang, Yuan-Fang

    2006-12-01

    Molecules interact through their surface residues. Calculation of the molecular surface of a protein structure is thus an important step for a detailed functional analysis. One of the main considerations in comparing existing methods for molecular surface computations is their speed. Most of the methods that produce satisfying results for small molecules fail to do so for large complexes. In this article, we present a level-set-based approach to compute and visualize a molecular surface at a desired resolution. The emerging level-set methods have been used for computing evolving boundaries in several application areas from fluid mechanics to computer vision. Our method provides a uniform framework for computing solvent-accessible, solvent-excluded surfaces and interior cavities. The computation is carried out very efficiently even for very large molecular complexes with tens of thousands of atoms. We compared our method to some of the most widely used molecular visualization tools (Swiss-PDBViewer, PyMol, and Chimera) and our results show that we can calculate and display a molecular surface 1.5-3.14 times faster on average than all three of the compared programs. Furthermore, we demonstrate that our method is able to detect all of the interior inaccessible cavities that can accommodate one or more water molecules. PMID:16621636

  5. Improvements to Level Set, Immersed Boundary methods for Interface Tracking

    NASA Astrophysics Data System (ADS)

    Vogl, Chris; Leveque, Randy

    2014-11-01

    It is not uncommon to find oneself solving a moving boundary problem under flow in the context of some application. Of particular interest is when the moving boundary exerts a curvature-dependent force on the liquid. Such a force arises when observing a boundary that is resistant to bending or has surface tension. Numerically speaking, stable numerical computation of the curvature can be difficult as it is often described in terms of high-order derivatives of either marker particle positions or of a level set function. To address this issue, the level set method is modified to track not only the position of the boundary, but the curvature as well. The definition of the signed-distance function that is used to modify the level set method is also used to develop an interpolation-free, closest-point method. These improvements are used to simulate a bending-resistant, inextensible boundary under shear flow to highlight area and volume conservation, as well as stable curvature calculation. Funded by a NSF MSPRF grant.

  6. GenoSets: Visual Analytic Methods for Comparative Genomics

    PubMed Central

    Cain, Aurora A.; Kosara, Robert; Gibas, Cynthia J.

    2012-01-01

    Many important questions in biology are, fundamentally, comparative, and this extends to our analysis of a growing number of sequenced genomes. Existing genomic analysis tools are often organized around literal views of genomes as linear strings. Even when information is highly condensed, these views grow cumbersome as larger numbers of genomes are added. Data aggregation and summarization methods from the field of visual analytics can provide abstracted comparative views, suitable for sifting large multi-genome datasets to identify critical similarities and differences. We introduce a software system for visual analysis of comparative genomics data. The system automates the process of data integration, and provides the analysis platform to identify and explore features of interest within these large datasets. GenoSets borrows techniques from business intelligence and visual analytics to provide a rich interface of interactive visualizations supported by a multi-dimensional data warehouse. In GenoSets, visual analytic approaches are used to enable querying based on orthology, functional assignment, and taxonomic or user-defined groupings of genomes. GenoSets links this information together with coordinated, interactive visualizations for both detailed and high-level categorical analysis of summarized data. GenoSets has been designed to simplify the exploration of multiple genome datasets and to facilitate reasoning about genomic comparisons. Case examples are included showing the use of this system in the analysis of 12 Brucella genomes. GenoSets software and the case study dataset are freely available at http://genosets.uncc.edu. We demonstrate that the integration of genomic data using a coordinated multiple view approach can simplify the exploration of large comparative genomic data sets, and facilitate reasoning about comparisons and features of interest. PMID:23056299

  7. A level-set method for interfacial flows with surfactant

    NASA Astrophysics Data System (ADS)

    Xu, Jian-Jun; Li, Zhilin; Lowengrub, John; Zhao, Hongkai

    2006-03-01

    A level-set method for the simulation of fluid interfaces with insoluble surfactant is presented in two-dimensions. The method can be straightforwardly extended to three-dimensions and to soluble surfactants. The method couples a semi-implicit discretization for solving the surfactant transport equation recently developed by Xu and Zhao [J. Xu, H. Zhao. An Eulerian formulation for solving partial differential equations along a moving interface, J. Sci. Comput. 19 (2003) 573-594] with the immersed interface method originally developed by LeVeque and Li and [R. LeVeque, Z. Li. The immersed interface method for elliptic equations with discontinuous coefficients and singular sources, SIAM J. Numer. Anal. 31 (1994) 1019-1044] for solving the fluid flow equations and the Laplace-Young boundary conditions across the interfaces. Novel techniques are developed to accurately conserve component mass and surfactant mass during the evolution. Convergence of the method is demonstrated numerically. The method is applied to study the effects of surfactant on single drops, drop-drop interactions and interactions among multiple drops in Stokes flow under a steady applied shear. Due to Marangoni forces and to non-uniform Capillary forces, the presence of surfactant results in larger drop deformations and more complex drop-drop interactions compared to the analogous cases for clean drops. The effects of surfactant are found to be most significant in flows with multiple drops. To our knowledge, this is the first time that the level-set method has been used to simulate fluid interfaces with surfactant.

  8. SET: a pupil detection method using sinusoidal approximation

    PubMed Central

    Javadi, Amir-Homayoun; Hakimi, Zahra; Barati, Morteza; Walsh, Vincent; Tcheang, Lili

    2015-01-01

    Mobile eye-tracking in external environments remains challenging, despite recent advances in eye-tracking software and hardware engineering. Many current methods fail to deal with the vast range of outdoor lighting conditions and the speed at which these can change. This confines experiments to artificial environments where conditions must be tightly controlled. Additionally, the emergence of low-cost eye tracking devices calls for the development of analysis tools that enable non-technical researchers to process the output of their images. We have developed a fast and accurate method (known as “SET”) that is suitable even for natural environments with uncontrolled, dynamic and even extreme lighting conditions. We compared the performance of SET with that of two open-source alternatives by processing two collections of eye images: images of natural outdoor scenes with extreme lighting variations (“Natural”); and images of less challenging indoor scenes (“CASIA-Iris-Thousand”). We show that SET excelled in outdoor conditions and was faster, without significant loss of accuracy, indoors. SET offers a low cost eye-tracking solution, delivering high performance even in challenging outdoor environments. It is offered through an open-source MATLAB toolkit as well as a dynamic-link library (“DLL”), which can be imported into many programming languages including C# and Visual Basic in Windows OS (www.eyegoeyetracker.co.uk). PMID:25914641

  9. Methods for assessing movement path recursion with application to African buffalo in South Africa

    USGS Publications Warehouse

    Bar-David, S.; Bar-David, I.; Cross, P.C.; Ryan, S.J.; Knechtel, C.U.; Getz, W.M.

    2009-01-01

    Recent developments of automated methods for monitoring animal movement, e.g., global positioning systems (GPS) technology, yield high-resolution spatiotemporal data. To gain insights into the processes creating movement patterns, we present two new techniques for extracting information from these data on repeated visits to a particular site or patch ("recursions"). Identification of such patches and quantification of recursion pathways, when combined with patch-related ecological data, should contribute to our understanding of the habitat requirements of large herbivores, of factors governing their space-use patterns, and their interactions with the ecosystem. We begin by presenting output from a simple spatial model that simulates movements of large-herbivore groups based on minimal parameters: resource availability and rates of resource recovery after a local depletion. We then present the details of our new techniques of analyses (recursion analysis and circle analysis) and apply them to data generated by our model, as well as two sets of empirical data on movements of African buffalo (Syncerus coffer): the first collected in Klaserie Private Nature Reserve and the second in Kruger National Park, South Africa. Our recursion analyses of model outputs provide us with a basis for inferring aspects of the processes governing the production of buffalo recursion patterns, particularly the potential influence of resource recovery rate. Although the focus of our simulations was a comparison of movement patterns produced by different resource recovery rates, we conclude our paper with a comprehensive discussion of how recursion analyses can be used when appropriate ecological data are available to elucidate various factors influencing movement. Inter alia, these include the various limiting and preferred resources, parasites, and topographical and landscape factors. ?? 2009 by the Ecological Society of America.

  10. Two methods for setting child-focused tuberculosis care targets

    PubMed Central

    Jenkins, H. E.; Chang, R.; Mpunga, J.; Becerra, M. C.

    2016-01-01

    Objective: To allocate resources for household contact investigations, tuberculosis (TB) programs need estimates of the numbers of child contacts requiring care. Design: We developed two methods to estimate annual numbers of child contacts aged 0–14 years requiring evaluation and treatment. Method 1 combines local data using simple formulas. Using publicly available data, Method 2 uses a linear regression model based on Demographic and Health Survey and World Bank data to estimate the number of children per household, then combines these results with case notifications and risk estimates of disease and infection. Results: Applying Method 1 to data from Malawi indicated that every year ~21 000 child contacts require evaluation and ~1900 should be diagnosed with TB. Applying Method 2 to all countries suggested that, globally, 2.41 million (95% uncertainty interval [UI] 2.36–2.46) children aged <5 years, and 5.07 million (95%UI 4.81–5.34) children aged 5–14 years live in households of adult patients with known TB. Of these, 239 014 (95%UI 118 649–478581) and 419 816 (95%UI 140600–1 268805), respectively, will have TB. An additional 848 453 (95%UI 705838–1 017551) and 2660 885 (95%UI 2080517–3 413 189), respectively, will be infected. Conclusion: It is feasible to use available data to set programmatic evaluation and treatment targets to improve care for child contacts of patients with TB. PMID:27358801

  11. Fuzzy set methods for object recognition in space applications

    NASA Technical Reports Server (NTRS)

    Keller, James M.

    1991-01-01

    During the reporting period, the development of the theory and application of methodologies for decision making under uncertainty was addressed. Two subreports are included; the first on properties of general hybrid operators, while the second considers some new research on generalized threshold logic units. In the first part, the properties of the additive gamma-model, where the intersection part is first considered to be the product of the input values and the union part is obtained by an extension of De Morgan's law to fuzzy sets, is explored. Then the Yager's class of union and intersection is used in the additive gamma-model. The inputs are weighted to some power that represents their importance and thus their contribution to the compensation process. In the second part, the extension of binary logic synthesis methods to multiple valued logic synthesis methods to enable the synthesis of decision networks when the input/output variables are not binary is discussed.

  12. A level set method for materials with texturally equilibrated pores

    NASA Astrophysics Data System (ADS)

    Ghanbarzadeh, Soheil; Hesse, Marc A.; Prodanović, Maša

    2015-09-01

    Textural equilibrium controls the distribution of the liquid phase in many naturally occurring porous materials such as partially molten rocks and alloys, salt-brine and ice-water systems. In these materials, pore geometry evolves to minimize the solid-liquid interfacial energy while maintaining a constant dihedral angle, θ, at solid-liquid contact lines. We present a level set method to compute an implicit representation of the liquid-solid interface in textural equilibrium with space-filling tessellations of multiple solid grains in three dimensions. Each grain is represented by a separate level set function and interfacial energy minimization is achieved by evolving the solid-liquid interface under surface diffusion to constant mean curvature surface. The liquid volume and dihedral angle constraints are added to the formulation using virtual convective and normal velocity terms. This results in an initial value problem for a system of non-linear coupled PDEs governing the evolution of the level sets for each grain, using the implicit representation of the solid grains as initial condition. A domain decomposition scheme is devised to restrict the computational domain of each grain to few grid points around the grain. The coupling between the interfaces is achieved in a higher level on the original computational domain. The spatial resolution of the discretization is improved through high-order spatial differentiation schemes and localization of computations through domain composition. Examples of three-dimensional solutions are also obtained for different grain distributions networks that illustrate the geometric flexibility of the method.

  13. In Order to Teach Me, You Have to Know Me: A Mixed-Methods Study of African-American Male Classroom Engagement

    ERIC Educational Resources Information Center

    Henderson, Jack L.

    2013-01-01

    Nationally, 30% of high school students do not graduate. Among this percentage, 50% are African-American. This study focused on at-promise African-American male classroom engagement where the researcher employed a mixed-methods methodology. Findings reveal that in order to engage and keep at-promise African-American males in high school, educators…

  14. Minimum dominating set-based methods for analyzing biological networks.

    PubMed

    Nacher, Jose C; Akutsu, Tatsuya

    2016-06-01

    The fast increase of 'multi-omics' data does not only pose a computational challenge for its analysis but also requires novel algorithmic methodologies to identify complex biological patterns and decipher the ultimate roots of human disorders. To that end, the massive integration of omics data with disease phenotypes is offering a new window into the cell functionality. The minimum dominating set (MDS) approach has rapidly emerged as a promising algorithmic method to analyze complex biological networks integrated with human disorders, which can be composed of a variety of omics data, from proteomics and transcriptomics to metabolomics. Here we review the main theoretical foundations of the methodology and the key algorithms, and examine the recent applications in which biological systems are analyzed by using the MDS approach. PMID:26773457

  15. Examining science achievement of African American females in suburban middle schools: A mixed methods study

    NASA Astrophysics Data System (ADS)

    Topping, Kecia C.

    This dissertation examined factors that affected the science achievement of African American females in suburban middle schools. The research literature informed that African American females are facing the barriers of race, gender, socioeconomic status, and cultural learning style preferences. Nationally used measurements of science achievement such as the Standardized Achievement Test, Tenth edition (SAT-10), National Assessment for Educational Progress, and National Center for Educational Statistics showed that African American females are continuing to falter in the areas of science when compared to other ethnic groups. This study used a transformative sequential explanatory mixed methods design. In the first, quantitative, phase, the relationships among the dependent variables, science subscale SAT-10 NCE scores, yearly averages, and the independent variables, attitude toward science scores obtained from the Modified Fennema-Sherman Attitudes toward Science Scale, socioeconomics, and caregiver status were tested. The participants were 150 African American females in grades 6 through 8 in four suburban middle schools located in the Southeastern United States. The results showed a positive, significant linear relationship between the females' attitude and their science subscale SAT-10 NCE scores and a positive, significant linear relationship between the females' attitudes and their yearly averages in science. The results also confirmed that attitude was a significant predictor of science subscale SAT-10 NCE scores for these females and that attitude and socioeconomics were significant predictors of the females' yearly averages in science. In the second, qualitative, phase, nine females purposefully selected from those who had high and low attitude towards science scores on the scale in the quantitative phase were interviewed. The themes that emerged revealed seven additional factors that impacted the females' science achievement. They were usefulness of science

  16. African American Organ Donor Registration: A Mixed Methods Design using the Theory of Planned Behavior

    PubMed Central

    DuBay, Derek A.; Ivankova, Nataliya; Herby, Ivan; Wynn, Theresa A.; Kohler, Connie; Berry, Beverly; Foushee, Herman; Carson, April; Redden, David T.; Holt, Cheryl; Siminoff, Laura; Fouad, Mona; Martin, Michelle Y.

    2015-01-01

    Context A large racial disparity exists in organ donation. Objective The purpose of this study was to identify factors associated with becoming a registered organ donor in among African Americans in Alabama. Methods The study utilized a concurrent mixed methods design guided by the Theory of Planned Behavior to analyze African American’s decisions to become a registered organ donor using both qualitative (focus groups) and quantitative (survey) methods. Results The sample consisted of 22 registered organ donors (ROD) and 65 non-registered participants (NRP) from six focus groups completed in urban (n=3) and rural (n=3) areas. Participants emphasized the importance of the autonomy to make one’s own organ donation decision and have this decision honored posthumously. One novel barrier to becoming a ROD was the perception that organs from African Americans were often unusable due to high prevalence of chronic medical conditions such as diabetes and hypertension. Another novel theme discussed as an advantage to becoming a ROD was the subsequent motivation to take responsibility for one’s health. Family and friends were the most common groups of persons identified as approving and disapproving of the decision to become a ROD. The most common facilitator to becoming a ROD was information, while fear and the lack of information were the most common barriers. In contrast, religious beliefs, mistrust and social justice themes were infrequently referenced as barriers to becoming a ROD. Discussion Findings from this study may be useful for prioritizing organ donation community-based educational interventions in campaigns to increase donor registration. PMID:25193729

  17. Modeling geomagnetically induced currents in the South African power transmission network using the finite element method

    NASA Astrophysics Data System (ADS)

    Matandirotya, Electdom; Cilliers, Pierre J.; Van Zyl, Robert R.

    2015-03-01

    Geomagnetically induced currents (GIC) are a result of time variations of the geomagnetic field, which induce a geoelectric field at the Earth's surface. Geomagnetic perturbations are enhanced during adverse space weather events called geomagnetic storms. All ground-based conductor networks can be affected by GIC during such events. As a way of assessing the magnitude of GIC expected in a particular technological system, models are developed, in which the computation of the induced geoelectric field is a key step. Computation of GIC in the South African power transmission network has so far been done using a uniform Earth model and improved using a layered Earth conductivity profile. In this work we present geoelectric field results obtained by using the finite element method (FEM) and improved GIC estimates using a realistic conductivity profile, magnetic field data interpolated from two South African observatories, and a new method for estimating the network coefficients, a and b, which map the north-south and east-west electric fields to their respective GIC components. The performance of the chosen FEM model demonstrates that it is an effective tool for GIC modeling. Unlike previous engineering techniques, our method for estimating the a and b coefficients from GIC and measured magnetic field data gives results that are independent of prior knowledge of the network configuration. The GIC estimated using the a and b coefficients obtained from the proposed method compares well with the measured GIC during the late October 2003 geomagnetic storm.

  18. Colonoscopy Education Among African-American Males in the Primary Care Setting of Bronx County, New York.

    PubMed

    Babikian, Razmig; Chang, Michelle

    2015-01-01

    Healthcare disparities are prevalent throughout the United States of America, particularly among low socioeconomic communities and minority groups. As primary care providers in Bronx, New York, the authors have noted that African American males often decline colonoscopy screening measures more frequently than other minorities. Ironically, the same cohort of African American men has the highest incidence of colon cancer and less favorable outcomes from chemotherapy intervention. In hopes of making a segue into a more informed conversation with our patients, we have developed an informative fact sheet for patients and their families on the basis of evidence-based literature. The objective was to employ this fact sheet to educate patients about colorectal cancer screening in an understandable and clinically effective manner. PMID:26422268

  19. Local innovation for improving primary care cardiology in resource-limited African settings: an insight on the Cardio Pad® project in Cameroon

    PubMed Central

    Jingi, Ahmadou M.; Kengne, André Pascal

    2014-01-01

    Cardiovascular disease (CVD) is an emerging threat to the health of populations in Africa. With the inadequate health infrastructures, understaffed and underfunded health systems, African countries are ill-prepared to cope with the increasing demand for care for CVD, particularly for populations in remote and underserved rural areas, where 60% of the population currently reside. Task shifting and telehealth have been suggested as strategies to overcome the current health workforce shortage in African countries, and to increase access to prevention and curative services for emerging CVD. However, strategies for promoting their incorporation into the existing health systems, have yet to be developed. The Cardio Pad® initiative (originating from Cameroon) seeks to provide appropriate solutions to improve the application of telemedicine for CVD prevention and control in remote African settings. The Cardio Pad® is a tele-cardiology device which provides a number of advantages in terms of cost, ease of use, autonomy and reduced technology requirements. It is a fully touch screen medical device which enables cardiac tests such as electrocardiograms (ECG) to be performed in remote underserved areas (rural areas for instance), while the test results are transferred wirelessly via mobile phone connection, to specialist physicians who can interpret them and provide assistance with case management. While most of the current telemedicine clinical services on the African continent receive most expertise from developed countries, the Cardio Pad®, a local invention by a 26-year-old Cameroon-trained engineer demonstrates how much innovative solutions to combat CVD and other health issues could and should be developed locally in Africa. PMID:25414826

  20. Profile Evolution Simulation in Etching Systems Using Level Set Methods

    NASA Technical Reports Server (NTRS)

    Hwang, Helen H.; Govindan, T. R.; Meyyappan, M.

    1998-01-01

    Semiconductor device profiles are determined by the characteristics of both etching and deposition processes. In particular, a highly anisotropic etch is required to achieve vertical sidewalls. However, etching is comprised of both anisotropic and isotropic components, due to ion and neutral fluxes, respectively. In Ar/Cl2 plasmas, for example, neutral chlorine reacts with the Si surfaces to form silicon chlorides. These compounds are then removed by the impinging ion fluxes. Hence the directionality of the ions (and thus the ion angular distribution function, or IAD), as well as the relative fluxes of neutrals and ions determines the amount of undercutting. One method of modeling device profile evolution is to simulate the moving solid-gas interface between the semiconductor and the plasma as a string of nodes. The velocity of each node is calculated and then the nodes are advanced accordingly. Although this technique appears to be relatively straightforward, extensive looping schemes are required at the profile corners. An alternate method is to use level set theory, which involves embedding the location of the interface in a field variable. The normal speed is calculated at each mesh point, and the field variable is updated. The profile comers are more accurately modeled as the need for looping algorithms is eliminated. The model we have developed is a 2-D Level Set Profile Evolution Simulation (LSPES). The LSPES calculates etch rates of a substrate in low pressure plasmas due to the incident ion and neutral fluxes. For a Si substrate in an Ar/C12 gas mixture, for example, the predictions of the LSPES are identical to those from a string evolution model for high neutral fluxes and two different ion angular distributions.(2) In the figure shown, the relative neutral to ion flux in the bulk plasma is 100 to 1. For a moderately isotropic ion angular distribution function as shown in the cases in the left hand column, both the LSPES (top row) and rude's string

  1. Overcoming barriers to priority setting using interdisciplinary methods.

    PubMed

    Peacock, Stuart; Mitton, Craig; Bate, Angela; McCoy, Bonnie; Donaldson, Cam

    2009-10-01

    Ten years ago, Holm's highly influential paper "Goodbye to the simple solutions: the second phase of priority setting" was published [Holm S. Goodbye to the simple solutions: the second phase of priority setting in health care. British Medical Journal 1998;317:1000-7]. Whilst attending the 2nd International Conference on Priorities in Health Care in London, Holm argued that the search for a rational set of decision-making rules was no longer adequate. Instead, the priority setting process itself was now thought to be more complex. Ten years later, the Conference returns to the UK for the first time, and it is timely to describe some new tools intended to assist both researchers and decision-makers seeking to develop both rational and fair and legitimate priority setting processes. In this paper we argue that to do so, researchers and decision-makers need to adopt an interdisciplinary and collaborative approach to priority setting. We focus on program budgeting and marginal analysis (PBMA) and bring together three hitherto separate interdisciplinary strands of the PBMA literature. Our aim is to assist researchers and decision-makers seeking to effectively develop and implement PBMA in practice. Specifically, we focus on the use of multi-criteria decision analysis, participatory action research, and accountability for reasonableness, drawn from the disciplines of decision analysis, sociology, and ethics respectively. PMID:19346024

  2. Where is the faith? Using a CBPR approach to propose adaptations to an evidence-based HIV prevention intervention for adolescents in African American faith settings.

    PubMed

    Lightfoot, Alexandra F; Taggart, Tamara; Woods-Jaeger, Briana A; Riggins, Linda; Jackson, Melvin R; Eng, Eugenia

    2014-08-01

    African American adolescents are at increased risk for HIV/AIDS. Using a community-based participatory research approach, we engaged three black churches in adapting an evidence-based HIV prevention intervention, Focus on Youth (FOY)+ImPACT, for faith settings. To identify potential adaptations to increase FOY's relevance, utility, and efficacy for faith settings, we conducted eight focus groups pre- and post-intervention. Recommendations for maintaining FOY's core elements and enhancing its cultural authenticity include the following: incorporating faith tools, building pastor capacity, strengthening parent-child communication skills, and expanding social support for parents and youth. Engaging faith communities in adapting and implementing evidence-based HIV prevention programs could reduce HIV/AIDS disparities. PMID:24639068

  3. Congruence of Standard Setting Methods for a Nursing Certification Examination.

    ERIC Educational Resources Information Center

    Fabrey, Lawrence J.; Raymond, Mark R.

    The American Nurses' Association certification provides professional recognition beyond licensure to nurses who pass an examination. To determine the passing score as it would be set by a representative peer group, a survey was mailed to a random sample of 200 recently certified nurses. Three questions were asked: (1) what percentage of examinees…

  4. Community response to intermittent preventive treatment of malaria in infants (IPTi) delivered through the expanded programme of immunization in five African settings

    PubMed Central

    Gysels, Marjolein; Pell, Christopher; Mathanga, Don P; Adongo, Philip; Odhiambo, Frank; Gosling, Roly; Akweongo, Patricia; Mwangi, Rose; Okello, George; Mangesho, Peter; Slutsker, Lawrence; Kremsner, Peter G; Grobusch, Martin P; Hamel, Mary J; Newman, Robert D; Pool, Robert

    2009-01-01

    Background IPTi delivered through EPI has been shown to reduce the incidence of clinical malaria by 20–59%. However, new health interventions can only be effective if they are also socially and culturally acceptable. It is also crucial to ensure that attitudes to IPTi do not negatively influence attitudes to and uptake of immunization, or that people do not misunderstand IPTi as immunization against malaria and neglect other preventive measures or delay treatment seeking. Methods These issues were studied in five African countries in the context of clinical trials and implementation studies of IPTi. Mixed methods were used, including structured questionnaires (1,296), semi-structured interviews (168), in-depth interviews (748) and focus group discussions (95) with mothers, fathers, health workers, community members, opinion leaders, and traditional healers. Participant observation was also carried out in the clinics. Results IPTi was widely acceptable because it resonated with existing traditional preventive practices and a general concern about infant health and good motherhood. It also fit neatly within already widely accepted routine vaccination. Acceptance and adherence were further facilitated by the hierarchical relationship between health staff and mothers and by the fact that clinic attendance had a social function for women beyond acquiring health care. Type of drug and regimen were important, with newer drugs being seen as more effective, but potentially also more dangerous. Single dose infant formulations delivered in the clinic seem to be the most likely to be both acceptable and adhered to. There was little evidence that IPTi per se had a negative impact on attitudes to EPI or that it had any affect on EPI adherence. There was also little evidence of IPTi having a negative impact on health seeking for infants with febrile illness or existing preventive practices. Conclusion IPTi is generally acceptable across a wide range of settings in Africa and

  5. Urban African American Parents’ Messages about Violence: A Mixed Methods Study

    PubMed Central

    Lindstrom Johnson, Sarah; Finigan, Nadine; Bradshaw, Catherine; Haynie, Denise; Cheng, Tina L.

    2015-01-01

    Family socialization, which includes parental control and support, plays an important role in reducing the likelihood of adolescent involvement in conflict. This study examined the strategies that urban parents living in neighborhoods with high crime rates suggest to help their adolescent children avoid or deescalate conflict. Data come from 48 African American parent/adolescent dyads recruited through the youths’ middle school. Dyads responded to three video-taped scenarios depicting youth in potential conflict situations. Qualitative methods were used to identify 11 strategies parents suggested to help youth avoid or deescalate conflict. Although the majority of parents advocated for non-violent solutions, these same parents described situations in which their child may need to use violence. These findings have important implications for family-focused violence prevention programs. PMID:26726283

  6. Stage at breast cancer diagnosis and distance from diagnostic hospital in a periurban setting: a South African public hospital case series of over 1,000 women.

    PubMed

    Dickens, Caroline; Joffe, Maureen; Jacobson, Judith; Venter, Francois; Schüz, Joachim; Cubasch, Herbert; McCormack, Valerie

    2014-11-01

    Advanced stage at diagnosis contributes to low breast cancer survival rates in sub-Saharan Africa. Living far from health services is known to delay presentation, but the effect of residential distance to hospital, the radius at which this effect sets in and the women most affected have not been quantified. In a periurban South African setting, we examined the effect of a geographic information system (GIS)-measured straight-line distance, from a patient's residence to diagnostic hospital, on stage at diagnosis in 1,071 public-sector breast cancer patients diagnosed during 2006-2012. Generalized linear models were used to estimate risk ratios for late stage (stage III/IV vs. stage I/II) associated with distance, adjusting for year of diagnosis, age, race and socioeconomic indicators. Mean age of patients was 55 years, 90% were black African and diagnoses were at stages I (5%), II (41%), III (46%) and IV (8%). Sixty-two percent of patients with distances >20 km (n = 338) had a late stage at diagnosis compared to 50% with distances <20 km (n = 713, p = 0.02). Risk of late stage at diagnosis was 1.25-fold higher (95% CI: 1.09, 1.42) per 30 km. Effects were pronounced in an underrepresented group of patients over age 70. This positive stage-distance association held to 40 km, and plateaued or slightly reversed in patients (9%) living beyond this distance. Studies of woman and the societal and healthcare-level influences on these delays and on the late stage at diagnosis distribution are needed to inform interventions to improve diagnostic stage and breast cancer survival in this and similar settings. PMID:24658866

  7. Stage at breast cancer diagnosis and distance from diagnostic hospital in a peri-urban setting: A South African public hospital case series of over 1000 women

    PubMed Central

    Dickens, Caroline; Joffe, Maureen; Jacobson, Judith; Venter, Francois; Schüz, Joachim; Cubasch, Herbert; McCormack, Valerie

    2014-01-01

    Advanced stage at diagnosis contributes to low breast cancer survival rates in sub-Saharan Africa. Living far from health services is known to delay presentation, but the effect of distance, the radius at which the effect sets in and the women most affected has not been quantified. In a peri-urban South African setting, we examined the effect of a GIS-measured straight-line distance, from a patient’s residence to diagnostic hospital, on stage at diagnosis in 1071 public-sector breast cancer patients diagnosed during 2006–12. Generalized linear models were used to estimate risk ratios for late stage (stage III/IV vs stage I/II) associated with distance, adjusting for year of diagnosis, age, race and socioeconomic indicators. Mean age of patients was 55 years, 90% were Black African, and diagnoses were at stages I (5%), II (41%), III (46%) and IV (8%). 62% of patients with distances >20 km (n=347) had a late stage at diagnosis compared to 50% with distances <20 km (n=724, p=0.02). Risk of late stage at diagnosis was 1.25-fold higher (95% CI: 1.09, 1.42) per 30 km. Effects were pronounced in an under-represented group of patients over age 70. This positive stage-distance association held to 40 km, and plateaued or slightly reversed in patients (9%) living beyond this distance. Studies of woman and the societal and healthcare-level influences on these delays and on the late stage at diagnosis distribution are needed to inform interventions that improve diagnostic stage and breast cancer survival rates in this and similar settings. PMID:24658866

  8. A test of the Lamendin method of age estimation in South African canines.

    PubMed

    Ackermann, Anja; Steyn, Maryna

    2014-03-01

    Age estimation in unknown adult skeletons remains a considerable problem in forensic anthropology. In 1992, Lamendin et al. published a non-destructive method of age estimation on single rooted teeth. With this method, periodontosis and root transparency are judged against root height, and these are then used in regression formulae to estimate age. The aim of this study was to test the accuracy of the Lamendin method on a large sample of canines of South Africans, and if necessary to adapt the formulae for this population. A sample of known sex, age and population group was used. This included 537 upper and lower canines from 498 skulls, and included black males, black females, white males and white females. The age of the individuals ranged from 20 to 90 years. The original formulae gave relatively poor results, and in an attempt to obtain better accuracy the formulae were adapted with the current data. Even after adaptation of the formulae, the highest correlation between estimated age and actual age remained low (R(2)=0.41), with mean errors ranging between 12 and 15 years. Periodontosis was better correlated with age than root transparency. The accuracy of the method was found to be much lower than what was originally published, but probably reflects biological reality and is on a par with other methods of adult age estimation. PMID:24445081

  9. Extension and Enhancement Methods for Setting Data Quality Objectives

    SciTech Connect

    D. Goodman

    2000-03-01

    The project developed statistical tools for the application of decision theory and operations research methods, including cost-benefit analysis, to the DQO process for environmental clean up. A pilot study was conducted, using these methods at the Hanford site, to estimate vadose zone contamination plumes under the SX tank farm, and to help plan further sampling.

  10. Device and Method for Gathering Ensemble Data Sets

    NASA Technical Reports Server (NTRS)

    Racette, Paul E. (Inventor)

    2014-01-01

    An ensemble detector uses calibrated noise references to produce ensemble sets of data from which properties of non-stationary processes may be extracted. The ensemble detector comprising: a receiver; a switching device coupled to the receiver, the switching device configured to selectively connect each of a plurality of reference noise signals to the receiver; and a gain modulation circuit coupled to the receiver and configured to vary a gain of the receiver based on a forcing signal; whereby the switching device selectively connects each of the plurality of reference noise signals to the receiver to produce an output signal derived from the plurality of reference noise signals and the forcing signal.

  11. 48 CFR 19.502-4 - Methods of conducting set-asides.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Methods of conducting set... SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Set-Asides for Small Business 19.502-4 Methods of conducting set-asides. (a) Total small business set-asides may be conducted by using simplified acquisition...

  12. Assessing the performance of methods to detect and quantify African dust in airborne particulates.

    PubMed

    Viana, Mar; Salvador, Pedro; Artíñano, Begoña; Querol, Xavier; Alastuey, Andrés; Pey, Jorge; Latz, Achim J; Cabañas, Mercè; Moreno, Teresa; García dos Santos, Saúl; Herce, María Dolores; Diez Hernández, Pablo; Romero García, Dolores; Fernández-Patier, Rosalía

    2010-12-01

    African dust (AD) contributions to particulate matter (PM) levels may be reported by Member States to the European Commission during justification of exceedances of the daily limit value (DLV). However, the detection and subsequent quantification of the AD contribution to PM levels is complex, and only two measurement-based methods are available in the literature: the Spanish-Portuguese reference method (SPR), and the Tel Aviv University method (TAU). In the present study, both methods were assessed. The SPR method was more conservative in the detection of episodes (71 days identified as AD by SPR, vs 81 by TAU), as it is less affected by interferences with local dust sources. The mean annual contribution of AD was lower with the TAU method than with SPR (2.7 vs 3.5 ± 1.5 μg/m(3)). The SPR and TAU AD time series were correlated with daily aluminum levels (a known tracer of AD), as well as with an AD source identified by the Positive Matrix Factorization (PMF) receptor model. Higher r(2) values were obtained with the SPR method than with TAU in both cases (r(2) = 0.72 vs 0.56, y = 0.05x vs y = 0.06x with aluminum levels; r(2)=0.79 vs 0.43, y = 0.8x vs y = 0.4x with the PMF source). We conclude that the SPR method is more adequate from an EU policy perspective (justification of DLV exceedances) due to the fact that it is more conservative than the TAU method. Based on our results, the TAU method requires adaptation of the thresholds in the algorithm to refine detection of low-impact episodes and avoid misclassification of local events as AD. PMID:21049991

  13. Fuzzy set methods for object recognition in space applications

    NASA Technical Reports Server (NTRS)

    Keller, James M.

    1991-01-01

    Progress on the following tasks is reported: (1) fuzzy set-based decision making methodologies; (2) feature calculation; (3) clustering for curve and surface fitting; and (4) acquisition of images. The general structure for networks based on fuzzy set connectives which are being used for information fusion and decision making in space applications is described. The structure and training techniques for such networks consisting of generalized means and gamma-operators are described. The use of other hybrid operators in multicriteria decision making is currently being examined. Numerous classical features on image regions such as gray level statistics, edge and curve primitives, texture measures from cooccurrance matrix, and size and shape parameters were implemented. Several fractal geometric features which may have a considerable impact on characterizing cluttered background, such as clouds, dense star patterns, or some planetary surfaces, were used. A new approach to a fuzzy C-shell algorithm is addressed. NASA personnel are in the process of acquiring suitable simulation data and hopefully videotaped actual shuttle imagery. Photographs have been digitized to use in the algorithms. Also, a model of the shuttle was assembled and a mechanism to orient this model in 3-D to digitize for experiments on pose estimation is being constructed.

  14. A Mixed Methods Study: African American Students' Performance Trends and Perceptions Towards Advanced Placement Literature Courses and Examinations

    ERIC Educational Resources Information Center

    Buford, Brandie J.

    2012-01-01

    The purpose of this mixed methods study was to describe the perceptions of African American students pertaining to their engagement in Advanced Placement English Literature and Composition course and Advanced Placement English Literature and Composition examination. A purposive sampling design was employed to select 12 participants from one urban…

  15. Sex-Role Egalitarian Attitudes and Gender Role Socialization Experiences of African American Men and Women: A Mixed Methods Paradigm

    ERIC Educational Resources Information Center

    Heard, Courtney Christian Charisse

    2013-01-01

    The purpose of this study was to assess the sex-role egalitarian attitudes and gender role socialization experiences of African American men and women. A sequential mixed-methods design was employed to research this phenomenon. The Sex-Role Egalitarianism Scale-Short Form BB (SRES-BB) was utilized to assess sex-role egalitarian attitudes (King…

  16. Methods to Increase Educational Effectiveness in an Adult Correctional Setting.

    ERIC Educational Resources Information Center

    Kuster, Byron

    1998-01-01

    A correctional educator reflects on methods that improve instructional effectiveness. These include teacher-student collaboration, clear goals, student accountability, positive classroom atmosphere, high expectations, and mutual respect. (SK)

  17. Childhood obesity perceptions among African American caregivers in a rural Georgia community: a mixed methods approach.

    PubMed

    Alexander, Dayna S; Alfonso, Moya L; Hansen, Andrew R

    2015-04-01

    Given the pivotal role of African American caregiver's perceptions of childhood obesity in rural areas, the inclusion of caregiver's perceptions could potentially reduce childhood obesity rates. The objective of the current study was to explore childhood obesity perceptions among African Americans in a rural Georgia community. This concurrent mixed methods study utilized two theoretical frameworks: Social Cognitive Theory and Social Ecological Model. Using a convenience sample, caregivers ages 22-65 years completed a paper-based survey (n = 135) and a face-to-face interview (n = 12) to explore perceptions of obesity risk factors, health complications, weight status, built environment features, and obesity prevention approaches. Descriptive statistics were generated and a six-step process was used for qualitative analysis. Participants commonly cited behavioral risk factors; yet, social aspects and appearance of the community were not considered contributing factors. Chronic diseases were reported as obesity health complications. Caregivers had a distorted view of their child's weight status. In addition, analysis revealed that caregivers assessed child's weight and height measurements by the child's appearance or a recent doctor visit. Environmental barriers reported by caregivers included safety concerns and insufficient physical activity venues and programs. Also, caregivers conveyed parents are an imperative component of preventing obesity. Although this study found caregivers were aware of obesity risk factors, health complications, built environment features, and prevention approaches their obesity perceptions were not incorporated into school or community prevention efforts. Findings suggest that children residing in rural areas are in need of tailored efforts that address caregiver perceptions of obesity. PMID:25218019

  18. Thriving, Managing, and Struggling: A Mixed Methods Study of Adolescent African Refugees’ Psychosocial Adjustment

    PubMed Central

    Weine, Stevan Merrill; Ware, Norma; Tugenberg, Toni; Hakizimana, Leonce; Dahnweih, Gonwo; Currie, Madeleine; Wagner, Maureen; Levin, Elise

    2013-01-01

    Objectives The purpose of this mixed method study was to characterize the patterns of psychosocial adjustment among adolescent African refugees in U.S. resettlement. Methods A purposive sample of 73 recently resettled refugee adolescents from Burundi and Liberia were followed for two years and qualitative and quantitative data was analyzed using a mixed methods exploratory design. Results Protective resources identified were the family and community capacities that can promote youth psychosocial adjustment through: 1) Finances for necessities; 2) English proficiency; 3) Social support networks; 4) Engaged parenting; 5) Family cohesion; 6) Cultural adherence and guidance; 7) Educational support; and, 8) Faith and religious involvement. The researchers first inductively identified 19 thriving, 29 managing, and 25 struggling youths based on review of cases. Univariate analyses then indicated significant associations with country of origin, parental education, and parental employment. Multiple regressions indicated that better psychosocial adjustment was associated with Liberians and living with both parents. Logistic regressions showed that thriving was associated with Liberians and higher parental education, managing with more parental education, and struggling with Burundians and living parents. Qualitative analysis identified how these factors were proxy indicators for protective resources in families and communities. Conclusion These three trajectories of psychosocial adjustment and six domains of protective resources could assist in developing targeted prevention programs and policies for refugee youth. Further rigorous longitudinal mixed-methods study of adolescent refugees in U.S. resettlement are needed. PMID:24205467

  19. Chlamydia trachomatis, Human Immunodeficiency Virus (HIV) Distribution and Sexual Behaviors across Gender and Age Group in an African Setting

    PubMed Central

    Djoba Siawaya, Joel Fleury

    2014-01-01

    Objective The purpose of this study was to (1) describe the distribution of Chlamydia trachomatis (CT) and Human Immunodeficiency Virus (HIV) cases across gender and age groups in Libreville (Gabon); (2) examine Gabonese Sexually Transmitted Infections (STIs)-related risk behaviour. Methods The sampled population was people attending the “Laboratoire National de Santé Plublique”. Between 2007 and 2011, 14 667 and 9 542 people respectively, were tested for CT and HIV infections. 1 854 of them were tested for both infections. We calculated CT and HIV rates across gender and age groups. Also analysed was the groups' contribution to the general CT and HIV epidemiology. STIs-related risk behaviours were assessed in 224 men and 795 women (between July 2011 and March 2013) who agreed and answered a questionnaire including questions on their marital status, number of sex partners, sexual practices, history of STIs, sex frequency and condom use. Results Data showed a 24% dropped in the CT infection rate between 2007 and 2010, followed by a 14% increase in 2011. The HIV infection rates for the same period were between 15% and 16%. The risk of a CT-positive subject getting HIV is about 0.71 times the risk of a CT-negative subject. Young adult aged between 18 and 35 years old represented 65.2% of people who had STIs. 80% of women and 66% of men confessed to an inconsistent use of condoms. 11.6% of women and 48% of men declared having multiple sex partners. 61% of questioned women and 67% of men declared knowing their HIV status. Conclusions In this Gabonese setting, the population-aged from18 to 35 years is the most affected by STIs. Other matters of concern are the inconsistent use of protection and sex with non-spousal or non-life partners. PMID:24594663

  20. Planning the Social Studies Programme for the Contemporary African Society.

    ERIC Educational Resources Information Center

    Enaohwo, J. Okpako

    1989-01-01

    Identifies characteristics of a viable social studies program for African nations, urging multidisciplinary and integrated approaches. Offers a cyclical framework for planning a curriculum which includes defining the problem, setting objectives, identifying methods of implementation, evaluation, and regeneration. (LS)

  1. Methods and circuitry for reconfigurable SEU/SET tolerance

    NASA Technical Reports Server (NTRS)

    Shuler, Jr., Robert L. (Inventor)

    2010-01-01

    A device is disclosed in one embodiment that has multiple identical sets of programmable functional elements, programmable routing resources, and majority voters that correct errors. The voters accept a mode input for a redundancy mode and a split mode. In the redundancy mode, the programmable functional elements are identical and are programmed identically so the voters produce an output corresponding to the majority of inputs that agree. In a split mode, each voter selects a particular programmable functional element output as the output of the voter. Therefore, in the split mode, the programmable functional elements can perform different functions, operate independently, and/or be connected together to process different parts of the same problem.

  2. Trust in healthcare settings: Scale development, methods, and preliminary determinants

    PubMed Central

    LoCurto, Jamie; Berg, Gina M

    2016-01-01

    The literature contains research regarding how trust is formed in healthcare settings but rarely discusses trust formation in an emergent care population. A literature review was conducted to determine which of the trust determinants are important for this process as well as how to develop a scale to measure trust. A search generated a total of 155 articles, 65 of which met eligibility criteria. Determinants that were important included the following: honesty, confidentiality, dependability, communication, competency, fiduciary responsibility, fidelity, and agency. The process of developing a scale includes the following: a literature review, qualitative analysis, piloting, and survey validation. Results suggest that physician behaviors are important in influencing trust in patients and should be included in scales measuring trust. Next steps consist of interviewing emergent care patients to commence the process of developing a scale.

  3. Smoking Cessation Intervention Preferences Among Urban African Americans: A Mixed Methods Approach.

    PubMed

    Baker, Cathy J; Palmer, Sheena D; Lee, Chia-Wen Vianne

    2016-06-01

    African Americans suffer disproportionately from smoking-related morbidity and mortality and make more quit attempts but report less success in quitting. Smokers tend to identify more strongly with African American culture. Qualitative interviews were conducted to elicit perceptions toward smoking and intervention content. Seventy-one African American smokers recruited from community locations participated. The majority stated they would not use any cessation aids if trying to quit smoking, despite the availability of free nicotine replacement. Acculturative stress scores were significantly higher in younger participants and those with higher income. Higher African American acculturation did not predict smoking cessation intervention preference. Family and social relationships were cited as both reasons for wanting to quit and reasons for continuing to smoke. Based on these findings, interventions for urban African Americans should address household members continuing to smoke, social/family connections, stress management, and cultural identification in urban areas. PMID:26809884

  4. Hanford Site groundwater monitoring: Setting, sources and methods

    SciTech Connect

    M.J. Hartman

    2000-04-11

    Groundwater monitoring is conducted on the Hanford Site to meet the requirements of the Resource Conservation and Recovery Act of 1976 (RCRA); Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA); U.S. Department of Energy (DOE) orders; and the Washington Administrative Code. Results of monitoring are published annually (e.g., PNNL-11989). To reduce the redundancy of these annual reports, background information that does not change significantly from year to year has been extracted from the annual report and published in this companion volume. This report includes a description of groundwater monitoring requirements, site hydrogeology, and waste sites that have affected groundwater quality or that require groundwater monitoring. Monitoring networks and methods for sampling, analysis, and interpretation are summarized. Vadose zone monitoring methods and statistical methods also are described. Whenever necessary, updates to information contained in this document will be published in future groundwater annual reports.

  5. Understanding the Role of Athletics and Resiliency in the Persistence and Success of African American Males in a Community College Setting

    ERIC Educational Resources Information Center

    James, Melinda Lloyd

    2013-01-01

    This dissertation examined the part athletics and resiliency played in degree completion of African American males. Specifically, it investigated three at-risk African American males and the dynamics of athletic participation and resiliency in their degree completion. In view of the fact that many African American students begin their higher…

  6. Fuzzy set methods for object recognition in space applications

    NASA Technical Reports Server (NTRS)

    Keller, James M.

    1992-01-01

    Progress on the following tasks is reported: feature calculation; membership calculation; clustering methods (including initial experiments on pose estimation); and acquisition of images (including camera calibration information for digitization of model). The report consists of 'stand alone' sections, describing the activities in each task. We would like to highlight the fact that during this quarter, we believe that we have made a major breakthrough in the area of fuzzy clustering. We have discovered a method to remove the probabilistic constraints that the sum of the memberships across all classes must add up to 1 (as in the fuzzy c-means). A paper, describing this approach, is included.

  7. Differential magnetometer method applied to measurement of geomagnetically induced currents in Southern African power networks

    NASA Astrophysics Data System (ADS)

    Matandirotya, Electdom; Cilliers, Pierre. J.; Van Zyl, Robert R.; Oyedokun, David T.; Villiers, Jean

    2016-03-01

    Geomagnetically induced currents (GICs) in conductors connected to the Earth are driven by an electric field produced by a time-varying magnetic field linked to magnetospheric-ionospheric current perturbations during geomagnetic storms. The GIC measurements are traditionally done on the neutral-to-ground connections of power transformers. A method of inferring the characteristics of GIC in power lines using differential magnetic field measurements is presented. Measurements of the GIC in the power lines connected to a particular power transformer are valuable in the verification of the modeling of GIC in the power transmission network. The differential magnetometer method (DMM) is an indirect method used to estimate the GIC in a power line. With the DMM, low-frequency GIC in the power line is estimated from the difference between magnetic field recordings made directly underneath the power line and at some distance away, where the magnetic field of the GIC in the transmission line has negligible effect. Results of the first application of the DMM to two selected sites of the Southern African power transmission network are presented. The results show that good quality GIC measurements are achieved through the DMM using Commercially-Off-The-Shelf magnetometers.

  8. Optimum allocation of conservation funds and choice of conservation programs for a set of African cattle breeds

    PubMed Central

    Reist-Marti, Sabine B; Abdulai, Awudu; Simianer, Henner

    2006-01-01

    Although funds for livestock conservation are limited there is little known about the optimal allocation of conservation funds. A new algorithm was used to allocate Mio US$ 1, 2, 3, 5 or unlimited funds, discounted over 50 years, on 23 African cattle breeds conserved with four different possible conservation programs. Additionally, Mio US$ 1 was preferably allocated to breeds with special traits. The conceptional in situ conservation programs strongly involve breeders and give them part of the responsibility for the conservation of the breed. Therefore, the pure in situ conservation was more efficient than cryoconservation or combined in situ and cryoconservation. The average annual discounted conservation cost for a breed can be as low as US$ 1000 to US$ 4400 depending on the design of the conservation program and the economic situation of the country of conservation. The choice of the breeds and the optimal conservation program and the amount of money allocated to each breed depend on many factors such as the amount of funds available, the conservation potential of each breed, the effects of the conservation program as well as its cost. With Mio US$ 1, 64% of the present diversity could be maintained over 50 years, which is 13% more than would be maintained if no conservation measures were implemented. Special traits could be conserved with a rather small amount of the total funds. Diversity can not be conserved completely, not even with unlimited funds. A maximum of 92% of the present diversity could be conserved with Mio US$ 10, leaving 8% of the diversity to unpredictable happenings. The suggested algorithm proved to be useful for optimal allocation of conservation funds. It allocated the funds optimally among breeds by identifying the most suited conservation program for each breed, also accounting for differences in currency exchange rates between the different countries. PMID:16451794

  9. Evaluating COSMO's lake module (FLake) for an East-African lake using a comprehensive set of lake temperature profiles

    NASA Astrophysics Data System (ADS)

    Thiery, W.; Martynov, A.; Darchambeau, F.; Demuzere, M.; van Lipzig, N.

    2012-04-01

    The African great lakes are of utmost importance for the local economy (fishing), as well as being essential to the survival of the local people. During last decades, these lakes have been changing rapidly and their evolution is a major concern. Hence, it is important to correctly represent them in regional climate models for simulations over tropical Africa. However, so far lake models have been developed and tested primarily for boreal conditions. In this study, for the first time the freshwater lake model FLake is evaluated over East-Africa, more specifically over lake Kivu. Meteorological observations from January 2003 to December 2008 from an automatic weather station in Bukavu, DRC, are used to drive the standalone version of FLake. For the evaluation, a unique dataset is used which contains over 200 temperature profiles recorded since 2002. Results show that FLake in its default configuration is very successful at reproducing both the timing and magnitude of the seasonal cycle at 5 m depth. Flake captures that this seasonality is regulated by the water vapour pressure, which constrains evaporation except during summer (JJA). A positive bias of ~1 K is attributed to the driving data, which are collected in the city and are therefore expected to mirror higher temperatures and lower wind speeds compared to the lake surface. The evaluation also showed that driving FLake with Era-Interim from the nearest pixel does only slightly deteriorate the model performance. Using forcing fields from the Canadian Regional Climate Model, version 5 (CRCM5) simulation output gives similar performance as Era-Interim. Furthermore, a drawback of FLake is that it does not account for salinity and its effect upon lake stratification, and therefore requires artificial initial conditions for both lake depth and bottom temperature in order to reproduce the correct mixing regime in lake Kivu. Further research will therefore aim at improving FLake's representation of tropical lakes.

  10. NVG adjustment methods, eyepiece focus settings, and vision

    NASA Astrophysics Data System (ADS)

    Van Arsdel, Richard; Baldwin, J. Bruce; Hausmann, Martha A.; Harrington, Lawrence K.; Craig, Jeffrey L.; Koepke, Corbin G.

    2006-05-01

    Several studies and many anecdotal reports indicate that aircrew members focus night vision goggle (NVG) eyepiece lenses to more negative powers than would be expected based on refractive error, presumably due to instrument myopia, "dark focus" myopia, and other factors. Excessive negative power stimulates accommodation, introducing risks from discomfort, fatigue, and blurred vision. Aircrew members are trained to employ specific adjustment techniques to minimize "over-minusing" of eyepiece lens powers, but those techniques are prone to error. The currently fielded AN/AVS-9 NVG (F4949) has a focus range of (+2.0) to (-6.0) diopters, and meets the needs of most aircrew. However, the new AN/AVS-10 NVG panoramic night vision goggle (PNVG) has a fixed focus of (-1.0) diopters due to engineering design constraints. Accessory snap-on lenses are available, but data are needed to optimize the distribution of lens powers to be acquired and maintained. This study involved the characterization of vision (visual acuity, perceived quality, and comfort) as a function of: 1) eyepiece focus setting using trial lenses; 2) F4949 eyepiece focus adjustments using a point source vs. a Hoffman 20/20 box; and 3) PNVG eyepiece lens selections using a lens bar vs. snap-on lens selections. Eight subjects with normal (20/20 corrected) vision ranging in age from 23 years to 49 participated in this study. The experiments were conducted in the Aerospace Vision Experimental Laboratory and the Dynamic Vision Assessment Facility at Wright Patterson AFB, Ohio using F4949 and PNVG devices with a custom-designed NVG-compatible computer-based visual acuity acquisition system.

  11. Comparison of methods to estimate physical activity and energy expenditure in African American children.

    PubMed

    Ramírez-Marrero, F A; Smith, B A; Sherman, W M; Kirby, T E

    2005-06-01

    Low levels of physical activity and high levels of obesity among children in the US is a public health concern. Accurate methods to estimate physical activity are needed to determine the efficacy of intervention programs and to explore relationships between daily physical activity and health status in children. The purpose of this study was to compare the simultaneous use of the Tritrac-R3D accelerometer (Tritrac), Yamax SW-200 Digiwalker step-counter (Digiwalker) and the Self Administered Physical Activity Checklist (SAPAC) to assess physical activity (PA) and energy expenditure (EE) in African-American children aged 7 to 10 years, using the doubly-labeled water (DLW) as the criterion method. Physical activity and energy expenditure were measured over seven consecutive days under free-living conditions. Resting metabolic rate and peak VO(2) were measured before the experimental period. There was no difference in physical activity energy expenditure (PAEE) measured by Tritrac or DLW (p > 0.05). Tritrac activity counts were highly correlated with DLW-PAEE (r = 0.81). High correlations between Digiwalker and DLW were observed when body weight was considered. A low correlation (r = 0.49) was observed between the physical activity energy expenditure by SAPAC and DLW. In conclusion, with some limitations the Tritrac and Digiwalker can provide useful and accurate information about PA and EE in 7- to 10-year-old children. PMID:15895319

  12. The giant Pan-African Hook Batholith, Central Zambia: A-type magmatism in a syn-collisional setting

    NASA Astrophysics Data System (ADS)

    Milani, Lorenzo; Lehmann, Jérémie; Naydenov, Kalin V.; Saalmann, Kerstin; Kinnaird, Judith A.; Daly, J. Stephen; Frei, Dirk; Lobo-Guerrero Sanz, Alberto

    2015-04-01

    The Pan-African Hook Batholith formed during the assembly of the Gondwana supercontinent between 570 and 520 Ma (U-Pb on zircon) as a result of syn-collisional stage interaction between the Congo and Kalahari Cratons1. The extension of the batholith, exposed and undercover, is estimated to be between 25,000 and 30,000 km2. The bimodal magmatism (mafic to predominantly felsic) is characterized by both an alkali-calcic and an alkalic suite, with the felsic rocks featuring a typical A-type, metaluminous, high Fe/Mg and K/Na geochemical signature. The scattered outcrops of gabbroic rocks, both tholeiitic and alkaline, suggest periodic input of mantle material, which, in some cases, interacted with metasomatizing fluids. Fractional crystallization is invoked for the most differentiated products, while Sr-Nd isotopes rule out any significant contribution from crustal assimilation. Exceptionally highly radiogenic Pb isotopes have been measured on both unaltered and hydrothermally altered rocks, and attest to the radiogenic character of the batholith. The Pb isotopes indicate that the anomalous signature was acquired during, or soon after, magma emplacement, and was likely enhanced by metasomatizing fluids. An enrichment in Th and U, affecting large portions of the crust along the southern margin of the Congo Craton, is suggested by comparable anomalous Pb isotopes measured in basement gneisses in the Domes Region, Zambian Copperbelt. Geochemical and isotopic evidence support interaction between mantle components and portions of the deep crust at pressures of < 10 kbar, while decompression melting of rising asthenospheric mantle ponding at the base of the crust heated, and ultimately melted, crustal material. Low-pressure mineral phases in metasedimentary wall rocks along the eastern margin of the pluton indicate that the magma was subsequently emplaced at shallow crustal depths. A crucial contribution to the crustal melting was likely provided by internal radiogenic heat

  13. Eina! Ouch! Eish! Professionals’ Perceptions of How Children with Cerebral Palsy Communicate About Pain in South African School Settings: Implications for the use of AAC

    PubMed Central

    Johnson, Ensa; Nilsson, Stefan; Adolfsson, Margareta

    2015-01-01

    Abstract Most children with severe cerebral palsy experience daily pain that affects their school performance. School professionals need to assess pain in these children, who may also have communication difficulties, in order to pay attention to the pain and support the children’s continued participation in school. In this study, South African school professionals’ perceptions of how they observed pain in children with cerebral palsy, how they questioned them about it and how the children communicated their pain back to them were investigated. Thirty-eight school professionals participated in five focus groups. Their statements were categorized using qualitative content analysis. From the results it became clear that professionals observed children’s pain communication through their bodily expressions, behavioral changes, and verbal and non-verbal messages. Augmentative and alternative communication (AAC) methods were rarely used. The necessity of considering pain-related vocabulary in a multilingual South African context, and of advocating for the use of AAC strategies to enable children with cerebral palsy to communicate their pain was highlighted in this study. PMID:26372118

  14. Comparing Yes/No Angoff and Bookmark Standard Setting Methods in the Context of English Assessment

    ERIC Educational Resources Information Center

    Hsieh, Mingchuan

    2013-01-01

    The Yes/No Angoff and Bookmark method for setting standards on educational assessment are currently two of the most popular standard-setting methods. However, there is no research into the comparability of these two methods in the context of language assessment. This study compared results from the Yes/No Angoff and Bookmark methods as applied to…

  15. Convergence of hausdorff approximation methods for the Edgeworth-Pareto hull of a compact set

    NASA Astrophysics Data System (ADS)

    Efremov, R. V.

    2015-11-01

    The Hausdorff methods comprise an important class of polyhedral approximation methods for convex compact bodies, since they have an optimal convergence rate and possess other useful properties. The concept of Hausdorff methods is extended to a problem arising in multicriteria optimization, namely, to the polyhedral approximation of the Edgeworth-Pareto hull (EPH) of a convex compact set. It is shown that the sequences of polyhedral sets generated by Hausdorff methods converge to the EPH to be approximated. It is shown that the Estimate Refinement method, which is most frequently used to approximate the EPH of convex compact sets, is a Hausdorff method and, hence, generates sequences of sets converging to the EPH.

  16. Mission to Mars set to revolutionise ESA's working methods

    NASA Astrophysics Data System (ADS)

    1999-03-01

    ESA took the decision in principle to send a mission to Mars shortly after the loss of the Russian spacecraft Mars '96 with several European experiments on board. The Agency wanted to build on the Mars '96 payload experience to design a mission that would put Europe at the leading-edge of Mars exploration. But ESA had to act quickly. Major space missions can take up to 11 years from concept to launch - and there was little more than six years to go before the positioning of the planets in 2003 would offer the shortest travel time to Mars with the highest payload. Budgetary pressures were also forcing ESA to look for cheaper ways of building spacecraft. A Mars mission therefore seemed a good candidate to explore cheaper and faster working methods. Mars Express (so called because of the streamlined development time) is the first of a new type of "flexible" missions in ESA's long-term scientific programme, which should be built and launched for about half the previous budget for similar missions. The global budget for Mars Express will actually be only150 million Euro including spacecraft development, launch by a Russian Soyuz/Fregat launcher, operations, testing and management costs. Costs are being saved by shortening the time from original concept to launch, re-using existing hardware, adopting new project management practices, and having access to reduced launcher costs. Selection of the scientific payload by ESA's scientific advisory bodies and mission definition by industry have been performed simultaneously, instead of sequentially as in previous missions. This has cut the time from concept to the awarding of today's design and development contract from about five years to little more than one year. The design and development phase will take under four years, compared with up to six previously. Mars Express is making maximum use of pre-existing technology, which is either "off-the-shelf" or has already been developed for the Rosetta mission (also due for launch

  17. Using community-based participatory mixed methods research to understand preconception health in African American communities of Arizona.

    PubMed

    Hussaini, Khaleel S; Hamm, Eric; Means, Toni

    2013-12-01

    The article discusses Arizona's strategic implementation and evaluation of the first time motherhood initiative grant (FTMI) to understand preconception health among African American men and women in Arizona. Longitudinal focus groups assessed whether African American men and women in the targeted areas comprehended and recalled the messages related to preconception health. Matched pre and posttests assessed community members' knowledge of preconception as well as physicians' perceptions on preconception health and care. Focus-group data were transcribed and coded by independent coders to conduct content analyses. Inter-rater reliability and agreement among coders, bivariate and multivariate statistics were conducted for quantitative matched pre and posttests data using SAS v9.2 (SAS Institute, Cary, NC). The social marketing campaign had limited impact in recall and comprehension of the preconception health message among African American men and women. Data from focus groups revealed that African American men and women perceived preconception health to be vital. And results from the pretest and posttests of community-based presentations, further supported this finding. Evidence from Grand Round presentations indicated that practitioners and health care providers had diverging views on preconception health. Use of community-based participatory mixed methods research can facilitate better understanding of the efficacy of strategic interventions such as FTMI and can provide valuable information on preconception health. Cost limitations often prohibit extensive evaluation of social marketing campaigns, hence, evaluators and researchers should assess the feasibility of conducting an efficacy study versus an effectiveness study in evaluating social marketing campaigns. PMID:23229170

  18. Women's views on consent, counseling and confidentiality in PMTCT: a mixed-methods study in four African countries

    PubMed Central

    2012-01-01

    Background Ambitious UN goals to reduce the mother-to-child transmission of HIV have not been met in much of Sub-Saharan Africa. This paper focuses on the quality of information provision and counseling and disclosure patterns in Burkina Faso, Kenya, Malawi and Uganda to identify how services can be improved to enable better PMTCT outcomes. Methods Our mixed-methods study draws on data obtained through: (1) the MATCH (Multi-country African Testing and Counseling for HIV) study's main survey, conducted in 2008-09 among clients (N = 408) and providers at health facilities offering HIV Testing and Counseling (HTC) services; 2) semi-structured interviews with a sub-set of 63 HIV-positive women on their experiences of stigma, disclosure, post-test counseling and access to follow-up psycho-social support; (3) in-depth interviews with key informants and PMTCT healthcare workers; and (4) document study of national PMTCT policies and guidelines. We quantitatively examined differences in the quality of counseling by country and by HIV status using Fisher's exact tests. Results The majority of pregnant women attending antenatal care (80-90%) report that they were explained the meaning of the tests, explained how HIV can be transmitted, given advice on prevention, encouraged to refer their partners for testing, and given time to ask questions. Our qualitative findings reveal that some women found testing regimes to be coercive, while disclosure remains highly problematic. 79% of HIV-positive pregnant women reported that they generally keep their status secret; only 37% had disclosed to their husband. Conclusion To achieve better PMTCT outcomes, the strategy of testing women in antenatal care (perceived as an exclusively female domain) when they are already pregnant needs to be rethought. When scaling up HIV testing programs, it is particularly important that issues of partner disclosure are taken seriously. PMID:22236097

  19. A multiple data set phylogeny for the endemic South African freshwater phreatoicidean isopod genus Mesamphisopus: Taxonomic and biogeographic implications.

    PubMed

    Gouws, G; Matthee, C A; Stewart, B A

    2010-05-01

    The obligate, freshwater isopod suborder Phreatoicidea is represented in South Africa by ten species contained within the endemic genus Mesamphisopus (Mesamphisopidae). Here, phylogenetic hypotheses are proposed to describe the evolutionary and biogeographic history of the genus with respect to drainage basin evolution and to assess species diversity, particularly among populations variably identified as Mesamphisopusabbreviatus or Mesamphisopusdepressus. Twenty-three ingroup taxa were examined, including eight known species and representatives of the M. abbreviatus-depressus complex. Allozyme data from 12 loci were analysed phenetically and cladistically. Mitochondrial DNA sequence data from the 12S ribosomal RNA and cytochrome c oxidase subunit I genes were analysed as a combined mtDNA data set and as a total data set in combination with recoded allele frequency data. Analyses retrieved (1) a monophyletic Mesamphisopus; (2) Mesamphisopustsitsikamma and a Mesamphisopuspaludosus+Mesamphisopuspenicillatus clade as basal lineages; (3) a Mesamphisopuscapensis+Mesamphisopusbaccatus clade; and (4) a clade containing the M. abbreviatus-depressus complex, with these taxa nested among several other species. Large genetic distances among taxa and the paraphyly of the members of the M. abbreviatus-depressus complex suggested the presence of hidden taxonomic diversity in Mesamphisopus. Clear biogeographic patterns emerged with lineages and clades mostly restricted to geographically discrete regions. Patterns showed remarkable similarity to those seen in the region's terrestrial fauna and bore no relation to the history of drainage basins. These patterns suggested that vicariance and, possibly, limited dispersal events played a major role in the evolution of Mesamphisopus. PMID:20096796

  20. Best practices in developing a national palliative care policy in resource limited settings: lessons from five African countries.

    PubMed

    Luyirika, Emmanuel Bk; Namisango, Eve; Garanganga, Eunice; Monjane, Lidia; Ginindza, Ntombi; Madonsela, Gugulethu; Kiyange, Fatia

    2016-01-01

    Given the high unmet need for palliative care in Africa and other resource limited settings, it is important that countries embrace the public health approach to increasing access through its integration within existing healthcare systems. To give this approach a strong foundation that would ensure sustainability, the World Health Organisation urges member states to ensure that policy environments are suitable for this intervention. The development, strengthening, and implementation of national palliative care policies is a priority. Given the lack of a critical mass of palliative care professionals in the region and deficiency in documenting and sharing best practices as part of information critical for regional development, policy development becomes a complex process. This article shares experiences with regard to best practices when advocating the national palliative care policies. It also tells about policy development process, the important considerations, and cites examples of policy content outlines in Africa. PMID:27563347

  1. Best practices in developing a national palliative care policy in resource limited settings: lessons from five African countries

    PubMed Central

    Luyirika, Emmanuel BK; Namisango, Eve; Garanganga, Eunice; Monjane, Lidia; Ginindza, Ntombi; Madonsela, Gugulethu; Kiyange, Fatia

    2016-01-01

    Given the high unmet need for palliative care in Africa and other resource limited settings, it is important that countries embrace the public health approach to increasing access through its integration within existing healthcare systems. To give this approach a strong foundation that would ensure sustainability, the World Health Organisation urges member states to ensure that policy environments are suitable for this intervention. The development, strengthening, and implementation of national palliative care policies is a priority. Given the lack of a critical mass of palliative care professionals in the region and deficiency in documenting and sharing best practices as part of information critical for regional development, policy development becomes a complex process. This article shares experiences with regard to best practices when advocating the national palliative care policies. It also tells about policy development process, the important considerations, and cites examples of policy content outlines in Africa. PMID:27563347

  2. Investigating alcohol consumption as a risk factor for HIV transmission in heterosexual settings in sub-Saharan African communities.

    PubMed

    Malunguza, N J; Hove-Musekwa, S D; Musuka, G; Mukandavire, Z

    2012-09-01

    Alcohol consumption and abuse is widespread in sub-Saharan Africa where most HIV infections occur and has been associated with risky sexual behaviors. It may therefore be one of the most common, potentially modifiable HIV risk factors in this region. A deterministic system of ordinary differential equations incorporating heterogeneity and biased sexual preferences is formulated to assess the effects of alcohol consumption on the transmission dynamics of the disease in heterosexual settings. Extensive qualitative analysis of the model is carried out and epidemic threshold such as the alcohol-induced reproductive number (RA), and equilibria are derived and their stabilities examined. The disease-free equilibrium is found to be globally attracting whenever the reproductive number is less than unity. In the model, heterosexuality is the source of transmissions, and therefore, targeting a reduction of the basic reproductive number (R0) should be primary objective for any intervention programme. We show that the preference to form partnerships amongst the heterogeneous groups influences the severity of disease and its evolution, and consequently the rate of partnership formation between females and alcohol consumers and their relative infectiousness over nondrinkers has a huge positive correlation with the alcohol-induced reproductive number and hence the epidemic. The proportion or absolute number of drinkers is shown to have minimal influence on the disease dynamics, and in a community with alcohol consumers, it is more prudent to reduce their risk sexual behavior rather than to fight the spread of alcohol consumption. Thus, intervention measures targeted at reducing heterogeneous group interactions and behavior change are the key to disease control in these settings. PMID:22798160

  3. Minimum Incidence of Adult Invasive Pneumococcal Disease in Blantyre, Malawi an Urban African Setting: A Hospital Based Prospective Cohort Study

    PubMed Central

    Bar-Zeev, Naor; Mtunthama, Neema; Gordon, Stephen B; Mwafulirwa, Gershom; French, Neil

    2015-01-01

    Invasive pneumococcal disease causes substantial morbidity and mortality in Africa. Evaluating population level indirect impact on adult disease of pneumococcal conjugate vaccine (PCV) programmes in infants requires baseline population incidence rates but these are often lacking in areas with limited disease surveillance. We used hospital based blood culture and cerebrospinal fluid surveillance to calculate minimal incidence of invasive pneumococcal disease in the adult (≥15 years old) population of Blantyre, a rapidly growing urban centre in southern Malawi, in the period preceding vaccine introduction. Invasive pneumococcal disease incidence in Blantyre district was high, mean 58.1 (95% confidence interval (CI): 53.7, 62.7) per 100,000 person years and peaking among 35 to 40 year olds at 108.8 (95%CI: 89.0, 131.7) mirroring the population age prevalence of HIV infection. For pneumococcal bacteraemia in urban Blantyre, mean incidence was 60.6 (95% CI: 55.2, 66.5) per 100,000 person years, peaking among 35 to 40 year olds at 114.8 (95%CI: 90.3, 143.9). We suspected that our surveillance may under-ascertain the true burden of disease, so we used location data from bacteraemic subjects and projected population estimates to calculate local sub-district incidence, then examined the impact of community level socio-demographic covariates as possible predictors of local sub-district incidence of pneumococcal and non-pneumococcal pathogenic bacteraemia. Geographic heterogeneity in incidence was marked with localised hotspots but ward level covariates apart from prison were not associated with pneumococcal bacteraemia incidence. Modelling suggests that the current sentinel surveillance system under-ascertains the true burden of disease. We outline a number of challenges to surveillance for pneumococcal disease in our low-resource setting. Subsequent surveillance in the vaccine era will have to account for geographic heterogeneity when evaluating population level indirect

  4. Minimum incidence of adult invasive pneumococcal disease in Blantyre, Malawi an urban african setting: a hospital based prospective cohort study.

    PubMed

    Bar-Zeev, Naor; Mtunthama, Neema; Gordon, Stephen B; Mwafulirwa, Gershom; French, Neil

    2015-01-01

    Invasive pneumococcal disease causes substantial morbidity and mortality in Africa. Evaluating population level indirect impact on adult disease of pneumococcal conjugate vaccine (PCV) programmes in infants requires baseline population incidence rates but these are often lacking in areas with limited disease surveillance. We used hospital based blood culture and cerebrospinal fluid surveillance to calculate minimal incidence of invasive pneumococcal disease in the adult (≥15 years old) population of Blantyre, a rapidly growing urban centre in southern Malawi, in the period preceding vaccine introduction. Invasive pneumococcal disease incidence in Blantyre district was high, mean 58.1 (95% confidence interval (CI): 53.7, 62.7) per 100,000 person years and peaking among 35 to 40 year olds at 108.8 (95%CI: 89.0, 131.7) mirroring the population age prevalence of HIV infection. For pneumococcal bacteraemia in urban Blantyre, mean incidence was 60.6 (95% CI: 55.2, 66.5) per 100,000 person years, peaking among 35 to 40 year olds at 114.8 (95%CI: 90.3, 143.9). We suspected that our surveillance may under-ascertain the true burden of disease, so we used location data from bacteraemic subjects and projected population estimates to calculate local sub-district incidence, then examined the impact of community level socio-demographic covariates as possible predictors of local sub-district incidence of pneumococcal and non-pneumococcal pathogenic bacteraemia. Geographic heterogeneity in incidence was marked with localised hotspots but ward level covariates apart from prison were not associated with pneumococcal bacteraemia incidence. Modelling suggests that the current sentinel surveillance system under-ascertains the true burden of disease. We outline a number of challenges to surveillance for pneumococcal disease in our low-resource setting. Subsequent surveillance in the vaccine era will have to account for geographic heterogeneity when evaluating population level indirect

  5. Multicriteria Decision Making Method Based on the Higher Order Hesitant Fuzzy Soft Set

    PubMed Central

    Farhadinia, B.

    2014-01-01

    The main goal of this contribution is to introduce the concept of higher order hesitant fuzzy soft set as an extension of fuzzy soft set that encompasses most of the existing extensions of fuzzy soft set as special cases. Furthermore, this new concept provides us with a method for dealing with multicriteria fuzzy decision making problems which are difficult to explain in other existing extensions of fuzzy soft set theory, especially when problems involve parameters with different-dimensional levels. PMID:27437496

  6. Prevalence and Predictors of Intestinal Helminth Infections Among Human Immunodeficiency Virus Type 1–Infected Adults in an Urban African Setting

    PubMed Central

    Modjarrad, Kayvon; Zulu, Isaac; Redden, David T.; Njobvu, Lungowe; Freedman, David O.; Vermund, Sten H.

    2009-01-01

    Sub-Saharan Africa is disproportionately burdened by intestinal helminth and human immunodeficiency virus (HIV)-1 infection. Recent evidence suggests detrimental immunologic effects from concomitant infection with the two pathogens. Few studies, however, have assessed the prevalence of and predictors for intestinal helminth infection among HIV-1–infected adults in urban African settings where HIV infection rates are highest. We collected and analyzed sociodemographic and parasitologic data from 297 HIV-1–infected adults (mean age = 31.1 years, 69% female) living in Lusaka, Zambia to assess the prevalence and associated predictors of helminth infection. We found at least one type of intestinal helminth in 24.9% of HIV-infected adults. Thirty-nine (52.7%) were infected with Ascaris lumbricoides, and 29 (39.2%) were infected with hookworm. More than 80% were light-intensity infections. A recent visit to a rural area, food shortage, and prior history of helminth infection were significant predictors of current helminth status. The high helminth prevalence and potential for adverse interactions between helminths and HIV suggests that helminth diagnosis and treatment should be part of routine HIV care. PMID:16222025

  7. Incarceration history relative to health, substance use, and violence in a sample of vulnerable South African women: implications for health services in criminal justice settings

    PubMed Central

    Johnson, Jennifer E; Carney, Tara; Kline, Tracy; Browne, Felicia A; Wechsberg, Wendee M

    2012-01-01

    International research has suggested that women in the criminal justice system carry a higher burden of many illnesses than women in the community, especially mental health disorders, substance use disorders, sexually transmitted infections, and a history of violent victimization. Knowledge of these health disparities is often used to advocate for relevant screening and treatment services for women passing through criminal justice custody within US and European settings. However, almost all criminal justice health research has taken place in high-income countries, with little or no research taking place in other countries, especially in South Africa. This baseline analysis compares the health, substance use, and violent victimization of women who have ever been incarcerated to those who have not, in a cross-sectional sample of 720 young, vulnerable, substance-using women in Cape Town, South Africa. Results of univariate tests indicated that women who had ever been incarcerated had worse health, mental health, and sexually transmitted infection indicators and were more likely to report use of substances and to have been victims of physical and sexual assault than women who had never been incarcerated. Passing through the criminal justice system appears to be a marker for a variety of current and/or future health service needs among vulnerable South African women, suggesting that screening, prevention, and treatment referral efforts at the time of intersection with the criminal justice system may reduce health burden for these women. PMID:24474876

  8. Maternal perceptions of factors contributing to severe under-nutrition among children in a rural African setting

    PubMed Central

    Abubakar, A; Holding, P; Mwangome, M; Maitland, K

    2013-01-01

    Introduction In developing countries, severe undernutrition in early childhood is associated with increased mortality and morbidity, and 10–40% of hospital admissions. The current study aimed to elicit maternal perceptions of factors that contribute to severe undernutrition among children in a rural Kenyan community in order to identify appropriate and acceptable targeted interventions. Methods The study consisted of 10 focus group discussions (FGDs) of between eight and ten mothers each, in a rural coastal community in Kenya. A grounded theory approach was used to analyse the FGD data. Results In all FGDs ‘financial constraints’ was the main reason given for severe undernutrition of children. The mothers reported the additional factors of inadequate food intake, ill health, inadequate care of children, heavy workload for mothers, inadequate control of family resources by women and a lack of resources for generating income for the family. The mothers also reported their local cultural belief that severe malnutrition was due to witchcraft and the violation of sexual taboos. Conclusions The mothers in the study community recognised multiple aetiologies for severe undernutrition. A multidisciplinary approach is needed address the range of issues raised and so combat severe undernutrition. Suggested interventions include poverty alleviation, medical education and psychosocial strategies. The content and approach of any program must address the need for variability, determined by individual and local needs, concerns, attitudes and beliefs. PMID:21323398

  9. A Mixed-Method Analysis of African-American Women's Attendance at an HIV Prevention Intervention

    ERIC Educational Resources Information Center

    Pinto, R. M.; McKay, M. M.

    2006-01-01

    Grounded in a model of service utilization, this study conceptualizes attendance of African-American women at an HIV prevention intervention as associated with influences across three ecological domains--individual, service (program), and social network. First, the texts of responses to semistructured, open-ended elicitation interviews were…

  10. Resisting Dominant Discourses: Implications of Indigenous, African Feminist Theory and Methods for Gender and Education Research

    ERIC Educational Resources Information Center

    Chilisa, Bagele; Ntseane, Gabo

    2010-01-01

    In this paper we explore tensions between Western gender theory and research, and post-colonial and indigenous feminist standpoints, which challenge us to re-define our roles as feminist-activist educators and researchers working with formerly colonised and historically marginalised communities. We discuss how African and Black feminist approaches…

  11. Health Risk Behaviors of African American Adolescents with Mild Mental Retardation: Prevalence Depends on Measurement Method.

    ERIC Educational Resources Information Center

    Pack, Robert P.; Browne, Dorothy; Wallander, Jan L.

    1998-01-01

    Health risk behaviors (substance use, violence, suicide, and car safety) of 194 African American urban adolescents with mild mental retardation were measured using either a confidential individual interview or an anonymous group survey. The survey methodology resulted in disclosure of more risk behaviors than the interview methodology. Elevated…

  12. A Researcher "Called" to "Taboo" Places?: A Burgeoning Research Method in African-Centered Education

    ERIC Educational Resources Information Center

    Shockley, Kmt G.

    2009-01-01

    This article presents a self-reflexive analysis of the complexities of conducting Afrocentric education research while living with a "double consciousness." Having been "called" to places that are considered to be "taboo" the author takes readers on a journey that begins in his busy mind and ends in on the African continent in a "rabbit hole."…

  13. Schumann Resonance spectra decomposition method and studies of the locations of the African thunderstorm centres

    NASA Astrophysics Data System (ADS)

    Dyrda, Michal; Kulak, Andrzej; Mlynarczyk, Janusz; Ostrowski, Michal; Kubisz, Jerzy; Michalec, Adam; Nieckarz, Zenon

    2014-05-01

    The idea, that the global atmospheric electric circuit is driven by global lightning activity was introduced at the beginning of the last century. Today, the different observational methods are used from satellites to the radio observations performed in the extremely low frequency (ELF) range to evaluate local as well as global lightning activity, its spatial and temporal variability and influence on our planet and Earth's climate. The ground-based thunderstorms observations, particularly ELF, also allow the measurements of the dipole moment of discharges. Global lightning activity excites the Earth-ionosphere cavity and the produced electromagnetic radiation is responsible for generating the Schumann resonance (SR). The interaction of the standing and travelling waves leads to asymmetric shape of the observational SR power spectra picks, which was noticed by Kułak et al. (2006). They proposed a spectral decomposition method, what allows to separate the resonant field from the travelling wave contribution, which can be dominant at small distances from the sources. In such approach, one can apply the inverse problem solution for determining a distance of the dominant signal source. The distances to the thunderstorm centres are calculated using the numerical as well as the analytical models for the electromagnetic waves propagation in the Earth-ionosphere cavity. The ELF electromagnetic waves, recorded by Hylaty ELF station, located in South-East of Poland are used to derive the distances to the most powerful thunderstorm centres located in Africa and hence to obtain 1-D thunderstorm lightning activity maps. The observational data taken in January and August 2011 were binned in 10 minute intervals and SR power spectra were derived. Then a curve describing seven asymmetric SR maxima was fitted to the spectrum for each time interval. We use chi-squared test to compare the resulted decomposed power spectra with curves obtained within the considered numerical and

  14. Preventing cognitive decline in older African Americans with mild cognitive impairment: design and methods of a randomized clinical trial.

    PubMed

    Rovner, Barry W; Casten, Robin J; Hegel, Mark T; Leiby, Benjamin E

    2012-07-01

    Mild Cognitive Impairment (MCI) affects 25% of older African Americans and predicts progression to Alzheimer's disease. An extensive epidemiologic literature suggests that cognitive, physical, and/or social activities may prevent cognitive decline. We describe the methods of a randomized clinical trial to test the efficacy of Behavior Activation to prevent cognitive decline in older African Americans with the amnestic multiple domain subtype of MCI. Community Health Workers deliver 6 initial in-home treatment sessions over 2-3 months and then 6 subsequent in-home booster sessions using language, materials, and concepts that are culturally relevant to older African Americans during this 24 month clinical trial. We are randomizing 200 subjects who are recruited from churches, senior centers, and medical clinics to Behavior Activation or Supportive Therapy, which controls for attention. The primary outcome is episodic memory as measured by the Hopkins Verbal Learning Test-Revised at baseline and at months 3, 12, 18, and 24. The secondary outcomes are general and domain-specific neuropsychological function, activities of daily living, depression, and quality-of-life. The negative results of recent clinical trials of drug treatments for MCI and Alzheimer's disease suggest that behavioral interventions may provide an alternative treatment approach to preserve cognition in an aging society. PMID:22406101

  15. A Model for the Roll-Out of Comprehensive Adult Male Circumcision Services in African Low-Income Settings of High HIV Incidence: The ANRS 12126 Bophelo Pele Project

    PubMed Central

    Lissouba, Pascale; Taljaard, Dirk; Rech, Dino; Doyle, Sean; Shabangu, Daniel; Nhlapo, Cynthia; Otchere-Darko, Josephine; Mashigo, Thabo; Matson, Caitlin; Lewis, David; Billy, Scott; Auvert, Bertran

    2010-01-01

    Background World Health Organization (WHO)/Joint United Nations Programme on AIDS (UNAIDS) has recommended adult male circumcision (AMC) for the prevention of heterosexually acquired HIV infection in men from communities where HIV is hyperendemic and AMC prevalence is low. The objective of this study was to investigate the feasibility of the roll-out of medicalized AMC according to UNAIDS/WHO operational guidelines in a targeted African setting. Methods and Findings The ANRS 12126 “Bophelo Pele” project was implemented in 2008 in the township of Orange Farm (South Africa). It became functional in 5 mo once local and ethical authorizations were obtained. Project activities involved community mobilization and outreach, as well as communication approaches aimed at both men and women incorporating broader HIV prevention strategies and promoting sexual health. Free medicalized AMC was offered to male residents aged 15 y and over at the project's main center, which had been designed for low-income settings. Through the establishment of an innovative surgical organization, up to 150 AMCs under local anesthesia, with sterilized circumcision disposable kits and electrocautery, could be performed per day by three task-sharing teams of one medical circumciser and five nurses. Community support for the project was high. As of November 2009, 14,011 men had been circumcised, averaging 740 per month in the past 12 mo, and 27.5% of project participants agreed to be tested for HIV. The rate of adverse events, none of which resulted in permanent damage or death, was 1.8%. Most of the men surveyed (92%) rated the services provided positively. An estimated 39.1% of adult uncircumcised male residents have undergone surgery and uptake is steadily increasing. Conclusion This study demonstrates that a quality AMC roll-out adapted to African low-income settings is feasible and can be implemented quickly and safely according to international guidelines. The project can be a model for

  16. Using Resampling To Estimate the Precision of an Empirical Standard-Setting Method.

    ERIC Educational Resources Information Center

    Muijtjens, Arno M. M.; Kramer, Anneke W. M.; Kaufman, David M.; Van der Vleuten, Cees P. M.

    2003-01-01

    Developed a method to estimate the cutscore precisions for empirical standard-setting methods by using resampling. Illustrated the method with two actual datasets consisting of 86 Dutch medical residents and 155 Canadian medical students taking objective structured clinical examinations. Results show the applicability of the method. (SLD)

  17. Participatory mapping in low-resource settings: Three novel methods used to engage Kenyan youth and other community members in community-based HIV prevention research.

    PubMed

    Green, Eric P; Warren, Virginia Rieck; Broverman, Sherryl; Ogwang, Benson; Puffer, Eve S

    2016-01-01

    Understanding the link between health and place can strengthen the design of health interventions, particularly in the context of HIV prevention. Individuals who might one day participate in such interventions - including youth - may further improve the design if engaged in a meaningful way in the formative research process. Increasingly, participatory mapping methods are being used to achieve both aims. We describe the development of three innovative mapping methods for engaging youth in formative community-based research: 'dot map' focus groups, geocaching games, and satellite imagery-assisted daily activity logs. We demonstrate that these methods are feasible and acceptable in a low-resource, rural African setting. The discussion outlines the merits of each method and considers possible limitations. PMID:27064073

  18. Level set discrete element method for three-dimensional computations with triaxial case study

    NASA Astrophysics Data System (ADS)

    Kawamoto, Reid; Andò, Edward; Viggiani, Gioacchino; Andrade, José E.

    2016-06-01

    In this paper, we outline the level set discrete element method (LS-DEM) which is a discrete element method variant able to simulate systems of particles with arbitrary shape using level set functions as a geometric basis. This unique formulation allows seamless interfacing with level set-based characterization methods as well as computational ease in contact calculations. We then apply LS-DEM to simulate two virtual triaxial specimens generated from XRCT images of experiments and demonstrate LS-DEM's ability to quantitatively capture and predict stress-strain and volume-strain behavior observed in the experiments.

  19. Organic and Elemental Carbon Filter Sets: Preparation Method and Interlaboratory Results

    PubMed Central

    Chai, Ming; Birch, M. Eileen; Deye, Greg

    2012-01-01

    Carbonaceous aerosols play an important role in climate, visibility, air quality, and human health effects, and they have been routinely monitored in workplace and environmental settings. Different thermal analysis methods have been applied to determine the carbon content of carbonaceous aerosols. Good agreement between results for total carbon (TC) generally has been found, but the organic and elemental carbon (OC and EC) fractions determined by different methods often disagree. Measurement uncertainty is mainly due to pyrolysis and charring of OC sample components. Lack of reference materials has impeded progress on method standardization and understanding method biases. A relatively simple method for generating matched filter sets having known OC–EC contents is reported. After generation and analysis of each set to confirm agreement between filters, the filter sets were distributed to six laboratories for an interlaboratory comparison. Analytical results indicate a uniform carbon distribution for the filter sets and good agreement between the participating laboratories. Relative standard deviations (RSDs) for mean TC (OC + EC), OC, and EC results for seven laboratories were <10, 11, and 12% (respectively). Except for one EC result (RSD = 16%), RSDs reported by individual laboratories for TC, OC, and EC were <12%. The method of filter generation is generally applicable and reproducible. Depending on the application, different filter loadings and types of OC materials can be employed. Matched filter sets prepared by the described approach can be used for determining the accuracy of OC–EC methods and thereby contribute to method standardization. PMID:22459320

  20. The Rising Burden of Diabetes and Hypertension in Southeast Asian and African Regions: Need for Effective Strategies for Prevention and Control in Primary Health Care Settings

    PubMed Central

    Mohan, Viswanathan; Seedat, Yackoob K.; Pradeepa, Rajendra

    2013-01-01

    Aim. To review the available literature on burden of diabetes mellitus (DM) and hypertension (HTN) and its coexistence in Southeast Asian (SEA) and the African (AFR) regions and to suggest strategies to improve DM and HTN prevention and control in primary health care (PHC) in the two regions. Methods. A systematic review of the papers published on DM, HTN, and prevention/control of chronic diseases in SEA and AFR regions between 1980 and December 2012 was included. Results. In the year 2011, SEA region had the second largest number of people with DM (71.4 million), while the AFR region had the smallest number (14.7 million). Screening studies identified high proportions (>50%) of individuals with previously undiagnosed HTN and DM in both of the SEA and AFR regions. Studies from both regions have shown that DM and HTN coexist in type 2 DM ranging from 20.6% in India to 78.4% in Thailand in the SEA region and ranging from 9.7% in Nigeria to 70.4% in Morocco in the AFR region. There is evidence that by lifestyle modification both DM and HTN can be prevented. Conclusion. To meet the twin challenge of DM and HTN in developing countries, PHCs will have to be strengthened with a concerted and multipronged effort to provide promotive, preventive, curative, and rehabilitative services. PMID:23573413

  1. The Reliability and Validity of the Comfort Level Method of Setting Hearing Aid Gain

    ERIC Educational Resources Information Center

    Walden, Brian E.; And Others

    1977-01-01

    Investigated in a series of experiments with 40 adults (20- to 70-years-old) having bilateral sensorineural hearing impairments was the test-retest reliability of the comfort level method for setting the acoustic gain of hearing aids, and the relationship between the comfort settings utilized in more realistic daily listening situations.…

  2. A Critical Analysis of the Body of Work Method for Setting Cut-Scores

    ERIC Educational Resources Information Center

    Radwan, Nizam; Rogers, W. Todd

    2006-01-01

    The recent increase in the use of constructed-response items in educational assessment and the dissatisfaction with the nature of the decision that the judges must make using traditional standard-setting methods created a need to develop new and effective standard-setting procedures for tests that include both multiple-choice and…

  3. Setting Cut-Scores: A Critical Review of the Angoff and Modified Angoff Methods

    ERIC Educational Resources Information Center

    Ricker, Kathryn L.

    2006-01-01

    The purpose of this article is to review critically the Angoff (1971) and modified Angoff methods for setting cut-scores. The criteria used in this review were originally proposed by Berk (1986). The assumptions of the Angoff method and other current issues surrounding this method are also discussed. Recommendations are made for using the Angoff…

  4. Matching the Judgmental Task with Standard Setting Panelist Expertise: The Item-Descriptor (ID) Matching Method

    ERIC Educational Resources Information Center

    Ferrara, Steve; Perie, Marianne; Johnson, Eugene

    2008-01-01

    Psychometricians continue to introduce new approaches to setting cut scores for educational assessments in an attempt to improve on current methods. In this paper we describe the Item-Descriptor (ID) Matching method, a method based on IRT item mapping. In ID Matching, test content area experts match items (i.e., their judgments about the knowledge…

  5. Combining the Best of Two Standard Setting Methods: The Ordered Item Booklet Angoff

    ERIC Educational Resources Information Center

    Smith, Russell W.; Davis-Becker, Susan L.; O'Leary, Lisa S.

    2014-01-01

    This article describes a hybrid standard setting method that combines characteristics of the Angoff (1971) and Bookmark (Mitzel, Lewis, Patz & Green, 2001) methods. The proposed approach utilizes strengths of each method while addressing weaknesses. An ordered item booklet, with items sorted based on item difficulty, is used in combination…

  6. A Body of Work Standard-Setting Method with Construct Maps

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Bunch, Michael B.; Deville, Craig; Viger, Steven G.

    2014-01-01

    This article describes a novel variation of the Body of Work method that uses construct maps to overcome problems of transparency, rater inconsistency, and scores gaps commonly occurring with the Body of Work method. The Body of Work method with construct maps was implemented to set cut-scores for two separate K-12 assessment programs in a large…

  7. African Refugee Parents' Involvement in Their Children's Schools: Barriers and Recommendations for Improvement

    ERIC Educational Resources Information Center

    Githembe, Purity Kanini

    2009-01-01

    The purpose of this study was to examine involvement of African refugee parents in the education of their elementary school children. The setting of the study was Northern and Southern Texas. African refugee parents and their children's teachers completed written surveys and also participated in interviews. In the study's mixed-method design,…

  8. Method effects in survey and focus group findings: understanding smoking cessation in low-SES African American women.

    PubMed

    Manfredi, C; Lacey, L; Warnecke, R; Balch, G

    1997-12-01

    The same pool of African American women participated in a survey and in focus groups on motivation to quit smoking. Findings from the two studies were compared to explore potential method effects. Consistent with each method's basic purposes, the survey identified variation in study variables based on accepted theory and association patterns among such variables. The focus groups discovered themes and images salient to the participants and highlighted the situational contexts that gave meaning to smoking and smoking cessation. Survey method limitations included poor sensitivity to topic salience and contextual meanings and a deductive mode that channeled interpretation of results within the boundaries predefined by the study's theoretical framework. Focus group method limitations included an overfocus on the most dramatic and uncommon evidence and lack of systematic ways to identify explanations that may underlie the participants' overt expressions. Together, the multiple findings complemented and explained each other. PMID:9408791

  9. An improved variational level set method for MR image segmentation and bias field correction.

    PubMed

    Zhan, Tianming; Zhang, Jun; Xiao, Liang; Chen, Yunjie; Wei, Zhihui

    2013-04-01

    In this paper, we propose an improved variational level set approach to correct the bias and to segment the magnetic resonance (MR) images with inhomogeneous intensity. First, we use a Gaussian distribution with bias field as a local region descriptor in two-phase level set formulation for segmentation and bias field correction of the images with inhomogeneous intensities. By using the information of the local variance in this descriptor, our method is able to obtain accurate segmentation results. Furthermore, we extend this method to three-phase level set formulation for brain MR image segmentation and bias field correction. By using this three-phase level set function to replace the four-phase level set function, we can reduce the number of convolution operations in each iteration and improve the efficiency. Compared with other approaches, this algorithm demonstrates a superior performance. PMID:23219273

  10. Type-2 fuzzy set extension of DEMATEL method combined with perceptual computing for decision making

    NASA Astrophysics Data System (ADS)

    Hosseini, Mitra Bokaei; Tarokh, Mohammad Jafar

    2013-05-01

    Most decision making methods used to evaluate a system or demonstrate the weak and strength points are based on fuzzy sets and evaluate the criteria with words that are modeled with fuzzy sets. The ambiguity and vagueness of the words and different perceptions of a word are not considered in these methods. For this reason, the decision making methods that consider the perceptions of decision makers are desirable. Perceptual computing is a subjective judgment method that considers that words mean different things to different people. This method models words with interval type-2 fuzzy sets that consider the uncertainty of the words. Also, there are interrelations and dependency between the decision making criteria in the real world; therefore, using decision making methods that cannot consider these relations is not feasible in some situations. The Decision-Making Trail and Evaluation Laboratory (DEMATEL) method considers the interrelations between decision making criteria. The current study used the combination of DEMATEL and perceptual computing in order to improve the decision making methods. For this reason, the fuzzy DEMATEL method was extended into type-2 fuzzy sets in order to obtain the weights of dependent criteria based on the words. The application of the proposed method is presented for knowledge management evaluation criteria.

  11. [Head and Neck Tumor Segmentation Based on Augmented Gradient Level Set Method].

    PubMed

    Zhang, Qiongmin; Zhang, Jing; Wang, Mintang; He, Ling; Men, Yi; Wei, Jun; Haung, Hua

    2015-08-01

    To realize the accurate positioning and quantitative volume measurement of tumor in head and neck tumor CT images, we proposed a level set method based on augmented gradient. With the introduction of gradient information in the edge indicator function, our proposed level set model is adaptive to different intensity variation, and achieves accurate tumor segmentation. The segmentation result has been used to calculate tumor volume. In large volume tumor segmentation, the proposed level set method can reduce manual intervention and enhance the segmentation accuracy. Tumor volume calculation results are close to the gold standard. From the experiment results, the augmented gradient based level set method has achieved accurate head and neck tumor segmentation. It can provide useful information to computer aided diagnosis. PMID:26710464

  12. Promoting Language and Executive Function in Educational Settings: The Drežancic Method

    ERIC Educational Resources Information Center

    Cozzani, Francesca; Zanobini, Mirella; Usai, Maria Carmen

    2016-01-01

    Research Findings: This study aims to evaluate the efficacy of linguistic training based on the use of the Drežancic method in educational settings. It is hypothesized that characteristics of this method, based on the typical stages of linguistic and cognitive development, could influence both language competence and executive function (EF). A…

  13. Evaluating the Bookmark Standard Setting Method: The Impact of Random Item Ordering

    ERIC Educational Resources Information Center

    Davis-Becker, Susan L.; Buckendahl, Chad W.; Gerrow, Jack

    2011-01-01

    Throughout the world, cut scores are an important aspect of a high-stakes testing program because they are a key operational component of the interpretation of test scores. One method for setting standards that is prevalent in educational testing programs--the Bookmark method--is intended to be a less cognitively complex alternative to methods…

  14. Theory and methods for accuracy assessment of thematic maps using fuzzy sets

    SciTech Connect

    Gopal, S.; Woodcock, C. )

    1994-02-01

    The use of fuzzy sets in map accuracy assessment expands the amount of information that can be provided regarding the nature, frequency, magnitude, and source of errors in a thematic map. The need for using fuzzy sets arises from the observation that all map locations do not fit unambiguously in a single map category. Fuzzy sets allow for varying levels of set membership for multiple map categories. A linguistic measurement scale allows the kinds of comments commonly made during map evaluations to be used to quantify map accuracy. Four tables result from the use of fuzzy functions, and when taken together they provide more information than traditional confusion matrices. The use of a hypothetical dataset helps illustrate the benefits of the new methods. It is hoped that the enhanced ability to evaluate maps resulting from the use of fuzzy sets will improve our understanding of uncertainty in maps and facilitate improved error modeling. 40 refs.

  15. Processor and method for developing a set of admissible fixture designs for a workpiece

    DOEpatents

    Brost, R.C.; Goldberg, K.Y.; Wallack, A.S.; Canny, J.

    1996-08-13

    A fixture process and method is provided for developing a complete set of all admissible fixture designs for a workpiece which prevents the workpiece from translating or rotating. The fixture processor generates the set of all admissible designs based on geometric access constraints and expected applied forces on the workpiece. For instance, the fixture processor may generate a set of admissible fixture designs for first, second and third locators placed in an array of holes on a fixture plate and a translating clamp attached to the fixture plate for contacting the workpiece. In another instance, a fixture vice is used in which first, second, third and fourth locators are used and first and second fixture jaws are tightened to secure the workpiece. The fixture process also ranks the set of admissible fixture designs according to a predetermined quality metric so that the optimal fixture design for the desired purpose may be identified from the set of all admissible fixture designs. 27 figs.

  16. Processor and method for developing a set of admissible fixture designs for a workpiece

    DOEpatents

    Brost, Randolph C.; Goldberg, Kenneth Y.; Canny, John; Wallack, Aaron S.

    1999-01-01

    Methods and apparatus are provided for developing a complete set of all admissible Type I and Type II fixture designs for a workpiece. The fixture processor generates the set of all admissible designs based on geometric access constraints and expected applied forces on the workpiece. For instance, the fixture processor may generate a set of admissible fixture designs for first, second and third locators placed in an array of holes on a fixture plate and a translating clamp attached to the fixture plate for contacting the workpiece. In another instance, a fixture vise is used in which first, second, third and fourth locators are used and first and second fixture jaws are tightened to secure the workpiece. The fixture process also ranks the set of admissible fixture designs according to a predetermined quality metric so that the optimal fixture design for the desired purpose may be identified from the set of all admissible fixture designs.

  17. Processor and method for developing a set of admissible fixture designs for a workpiece

    DOEpatents

    Brost, Randolph C.; Goldberg, Kenneth Y.; Wallack, Aaron S.; Canny, John

    1996-01-01

    A fixture process and method is provided for developing a complete set of all admissible fixture designs for a workpiece which prevents the workpiece from translating or rotating. The fixture processor generates the set of all admissible designs based on geometric access constraints and expected applied forces on the workpiece. For instance, the fixture processor may generate a set of admissible fixture designs for first, second and third locators placed in an array of holes on a fixture plate and a translating clamp attached to the fixture plate for contacting the workpiece. In another instance, a fixture vice is used in which first, second, third and fourth locators are used and first and second fixture jaws are tightened to secure the workpiece. The fixture process also ranks the set of admissible fixture designs according to a predetermined quality metric so that the optimal fixture design for the desired purpose may be identified from the set of all admissible fixture designs.

  18. Processor and method for developing a set of admissible fixture designs for a workpiece

    DOEpatents

    Brost, R.C.; Goldberg, K.Y.; Canny, J.; Wallack, A.S.

    1999-01-05

    Methods and apparatus are provided for developing a complete set of all admissible Type 1 and Type 2 fixture designs for a workpiece. The fixture processor generates the set of all admissible designs based on geometric access constraints and expected applied forces on the workpiece. For instance, the fixture processor may generate a set of admissible fixture designs for first, second and third locators placed in an array of holes on a fixture plate and a translating clamp attached to the fixture plate for contacting the workpiece. In another instance, a fixture vise is used in which first, second, third and fourth locators are used and first and second fixture jaws are tightened to secure the workpiece. The fixture process also ranks the set of admissible fixture designs according to a predetermined quality metric so that the optimal fixture design for the desired purpose may be identified from the set of all admissible fixture designs. 44 figs.

  19. The relative contribution of viral and bacterial sexually transmitted infections on HIV acquisition in southern African women in the Methods for Improving Reproductive Health in Africa study.

    PubMed

    Venkatesh, K K; van der Straten, A; Cheng, H; Montgomery, E T; Lurie, M N; Chipato, T; Ramjee, G; Blanchard, K; Padian, N S; Mayer, K H; de Bruyn, G

    2011-04-01

    We assess the relative contribution of viral and bacterial sexually transmitted infections (STIs) on HIV acquisition among southern African women in a nested case-control study within the Methods for Improving Reproductive Health in Africa (MIRA) trial. Cases were women with incident HIV infection; controls were HIV-uninfected at the time of case seroconversion selected in a 1 to 3 case to control ratio (risk-set sampling), matched on study site and time of follow-up. Conditional logistic regression models were used to calculate adjusted odds ratios (AORs) and population-attributable fractions (PAF). Among 4948 enrolled women, we analysed 309 cases and 927 controls. The overall HIV incidence rate was 4.0 per 100 women-years. The incidence of HIV infection was markedly higher in women who had prevalent Herpes simplex virus type 2 (HSV-2) (AOR: 2.14; 95% confidence interval [CI]: 1.55-2.96), incident HSV-2 (AOR: 4.43; 95% CI: 1.77-11.05) and incident Neisseria gonorrhoeae (AOR: 6.92; 95% CI: 3.01-15.90). The adjusted PAF of HIV incidence for prevalent HSV-2 was 29.0% (95% CI: 16.8-39.3), for incident HSV-2 2.1% (95% CI: 0.6-3.6) and for incident N. gonorrhoeae 4.1% (95% CI: 2.5-5.8). Women's greatest risk factors for HIV acquisition were incident bacterial and viral STIs. Women-centred interventions aimed at decreasing HIV incidence in young African women need to address these common co-morbid conditions. PMID:21515755

  20. Automatic segmentation of Leishmania parasite in microscopic images using a modified CV level set method

    NASA Astrophysics Data System (ADS)

    Farahi, Maria; Rabbani, Hossein; Talebi, Ardeshir; Sarrafzadeh, Omid; Ensafi, Shahab

    2015-12-01

    Visceral Leishmaniasis is a parasitic disease that affects liver, spleen and bone marrow. According to World Health Organization report, definitive diagnosis is possible just by direct observation of the Leishman body in the microscopic image taken from bone marrow samples. We utilize morphological and CV level set method to segment Leishman bodies in digital color microscopic images captured from bone marrow samples. Linear contrast stretching method is used for image enhancement and morphological method is applied to determine the parasite regions and wipe up unwanted objects. Modified global and local CV level set methods are proposed for segmentation and a shape based stopping factor is used to hasten the algorithm. Manual segmentation is considered as ground truth to evaluate the proposed method. This method is tested on 28 samples and achieved 10.90% mean of segmentation error for global model and 9.76% for local model.

  1. Influences on HIV Testing among Young African-American Men Who Have Sex with Men and the Moderating Effect of the Geographic Setting

    ERIC Educational Resources Information Center

    Mashburn, Andrew J.; Peterson, John L.; Bakeman, Roger; Miller, Robin L.; Clark, Leslie F.

    2004-01-01

    This study examined the influence of demographic characteristics, risk behaviors, knowledge, and psychosocial variables on HIV testing among a sample (n = 551) of young African-American men who have sex with men (MSM) from three cities--Atlanta (n = 241), Birmingham (n = 174), and Chicago (n = 136). Among the entire sample of young men, age,…

  2. The Effects of Check-In Check-Out on the Social and Academic Planning and Outcomes of African-American Males in an Urban Secondary Setting

    ERIC Educational Resources Information Center

    Toms, Ozalle Marie

    2012-01-01

    According to Planty et al. (2009) in 2006, nearly 3.3 million students in the United States received out of school suspensions, demonstrating that exclusionary discipline is on the rise and a frequently used practice in schools across the country. Research shows that African Americans are suspended at higher rates and are more likely to receive…

  3. Application of Multi-Sensor Information Fusion Method Based on Rough Sets and Support Vector Machine

    NASA Astrophysics Data System (ADS)

    Xue, Jinxue; Wang, Guohu; Wang, Xiaoqiang; Cui, Fengkui

    In order to improve the precision and date processing speed of multi-sensor information fusion, a kind of multi-sensor data fusion process algorithm has been studied in this paper. First, based on rough set theory (RS) to attribute reduction the parameter set, we use the advantages of rough set theory in dealing with large amount of data to eliminate redundant information. Then, the data can be trained and classified by Support Vector Machine (SYM). Experimental results showed that this method can improve the speed and accuracy of multi-sensor fusion system.

  4. Diagnostic methods for African horsesickness virus using monoclonal antibodies to structural and non-structural proteins.

    PubMed

    Ranz, A I; Miguet, J G; Anaya, C; Venteo, A; Cortés, E; Vela, C; Sanz, A

    1992-11-01

    A panel of 32 hybridoma cell lines secreting monoclonal antibodies (MAbs) reactive with African horsesickness virus serotype 4 (AHSV-4) has been developed. Four of the MAbs recognized the major core antigen VP7, twenty recognized the outer capsid protein VP2 and eight reacted with the non-structural protein NS1. With the VP7-specific MAbs a rapid and sensitive double antibody sandwich immunoassay has been developed to detect viral antigen in infected Vero cells and in spleen tissue from AHSV-infected horses. The sensitivity of the assay is 10 ng viral antigen per 100 microliters. The NS1-specific MAbs allowed visualization by immunofluorescence of tubule-like structures in the cytoplasm of infected Vero cells. This can be very useful as a confirmatory diagnostic procedure. The antigenic map of the outer capsid VP2 protein with MAbs is also reported. PMID:1481354

  5. Use of simulated data sets to evaluate the fidelity of metagenomic processing methods

    SciTech Connect

    Mavromatis, K; Ivanova, N; Barry, Kerrie; Shapiro, Harris; Goltsman, Eugene; McHardy, Alice C.; Rigoutsos, Isidore; Salamov, Asaf; Korzeniewski, Frank; Land, Miriam L; Lapidus, Alla L.; Grigoriev, Igor; Hugenholtz, Philip; Kyrpides, Nikos C

    2007-01-01

    Metagenomics is a rapidly emerging field of research for studying microbial communities. To evaluate methods presently used to process metagenomic sequences, we constructed three simulated data sets of varying complexity by combining sequencing reads randomly selected from 113 isolate genomes. These data sets were designed to model real metagenomes in terms of complexity and phylogenetic composition. We assembled sampled reads using three commonly used genome assemblers (Phrap, Arachne and JAZZ), and predicted genes using two popular gene-finding pipelines (fgenesb and CRITICA/GLIMMER). The phylogenetic origins of the assembled contigs were predicted using one sequence similarity-based ( blast hit distribution) and two sequence composition-based (PhyloPythia, oligonucleotide frequencies) binning methods. We explored the effects of the simulated community structure and method combinations on the fidelity of each processing step by comparison to the corresponding isolate genomes. The simulated data sets are available online to facilitate standardized benchmarking of tools for metagenomic analysis.

  6. Use of simulated data sets to evaluate the fidelity of Metagenomicprocessing methods

    SciTech Connect

    Mavromatis, Konstantinos; Ivanova, Natalia; Barry, Kerri; Shapiro, Harris; Goltsman, Eugene; McHardy, Alice C.; Rigoutsos, Isidore; Salamov, Asaf; Korzeniewski, Frank; Land, Miriam; Lapidus, Alla; Grigoriev, Igor; Richardson, Paul; Hugenholtz, Philip; Kyrpides, Nikos C.

    2006-12-01

    Metagenomics is a rapidly emerging field of research for studying microbial communities. To evaluate methods presently used to process metagenomic sequences, we constructed three simulated data sets of varying complexity by combining sequencing reads randomly selected from 113 isolate genomes. These data sets were designed to model real metagenomes in terms of complexity and phylogenetic composition. We assembled sampled reads using three commonly used genome assemblers (Phrap, Arachne and JAZZ), and predicted genes using two popular gene finding pipelines (fgenesb and CRITICA/GLIMMER). The phylogenetic origins of the assembled contigs were predicted using one sequence similarity--based (blast hit distribution) and two sequence composition--based (PhyloPythia, oligonucleotide frequencies) binning methods. We explored the effects of the simulated community structure and method combinations on the fidelity of each processing step by comparison to the corresponding isolate genomes. The simulated data sets are available online to facilitate standardized benchmarking of tools for metagenomic analysis.

  7. Weld defect detection on digital radiographic image using level set method

    NASA Astrophysics Data System (ADS)

    Halim, Suhaila Abd; Petrus, Bertha Trissan; Ibrahim, Arsmah; Manurung, Yupiter HP; Jayes, Mohd Idris

    2013-09-01

    Segmentation is the most critical task and widely used to obtain useful information in image processing. In this study, Level set based on Chan Vese method is explored and applied to define weld defect on digital radiographic image and its accuracy is evaluated to measure its performance. A set of images with region of interest (ROI) that contain defect are used as input image. The ROI image is pre-processed to improve their quality for better detection. Then, the image is segmented using level set method that is implemented using MATLAB R2009a. The accuracy of the method is evaluated using Receiver Operating Characteristic (ROC). Experimental results show that the method generated an area underneath the ROC of 0.7 in the set of images and the operational point reached corresponds to 0.6 of sensitivity and 0.8 of specificity. The application of segmentation technique such as Chan-Vese level set able to assist radiographer in detecting the defect on digital radiographic image accurately.

  8. Study on the RF Set Point for the PEFP DTL by using a phase scan method

    NASA Astrophysics Data System (ADS)

    Jang, Ji-Ho; Kwon, Hyeok-Jung; Cho, Yong-Sub

    2012-12-01

    The drift tube linac (DTL) is used to accelerate proton beams from 20 MeV to 100 MeV in the linear accelerator of the Proton Engineering Frontier Project (PEFP). The phase scan signature method is a common technique to determine the radio-frequency (rf) set point, including the rf amplitude and phase, in DTL tanks. In this work, we applied the phase scan method to the first tank of the PEFP's DTL in order to study the procedure for determining the rf set point by using artificial experimental data generated by using the PARMILA code.

  9. Breast mass segmentation in digital mammography based on pulse coupled neural network and level set method

    NASA Astrophysics Data System (ADS)

    Xie, Weiying; Ma, Yide; Li, Yunsong

    2015-05-01

    A novel approach to mammographic image segmentation, termed as PCNN-based level set algorithm, is presented in this paper. Just as its name implies, a method based on pulse coupled neural network (PCNN) in conjunction with the variational level set method for medical image segmentation. To date, little work has been done on detecting the initial zero level set contours based on PCNN algorithm for latterly level set evolution. When all the pixels of the input image are fired by PCNN, the small pixel value will be a much more refined segmentation. In mammographic image, the breast tumor presents big pixel value. Additionally, the mammographic image with predominantly dark region, so that we firstly obtain the negative of mammographic image with predominantly dark region except the breast tumor before all the pixels of an input image are fired by PCNN. Therefore, in here, PCNN algorithm is employed to achieve mammary-specific, initial mass contour detection. After that, the initial contours are all extracted. We define the extracted contours as the initial zero level set contours for automatic mass segmentation by variational level set in mammographic image analysis. What's more, a new proposed algorithm improves external energy of variational level set method in terms of mammographic images in low contrast. In accordance with the gray scale of mass region in mammographic image is higher than the region surrounded, so the Laplace operator is used to modify external energy, which could make the bright spot becoming much brighter than the surrounded pixels in the image. A preliminary evaluation of the proposed method performs on a known public database namely MIAS, rather than synthetic images. The experimental results demonstrate that our proposed approach can potentially obtain better masses detection results in terms of sensitivity and specificity. Ultimately, this algorithm could lead to increase both sensitivity and specificity of the physicians' interpretation of

  10. Global adaptive rank truncated product method for gene-set analysis in association studies.

    PubMed

    Vilor-Tejedor, Natalia; Calle, M Luz

    2014-08-01

    Gene set analysis (GSA) aims to assess the overall association of a set of genetic variants with a phenotype and has the potential to detect subtle effects of variants in a gene or a pathway that might be missed when assessed individually. We present a new implementation of the Adaptive Rank Truncated Product method (ARTP) for analyzing the association of a set of Single Nucleotide Polymorphisms (SNPs) in a gene or pathway. The new implementation, referred to as globalARTP, improves the original one by allowing the different SNPs in the set to have different modes of inheritance. We perform a simulation study for exploring the power of the proposed methodology in a set of scenarios with different numbers of causal SNPs with different effect sizes. Moreover, we show the advantage of using the gene set approach in the context of an Alzheimer's disease case-control study where we explore the endocytosis pathway. The new method is implemented in the R function globalARTP of the globalGSA package available at http://cran.r-project.org. PMID:25082012

  11. The research of object selection method based on rough set in map generalization

    NASA Astrophysics Data System (ADS)

    Li, Wenjing; Long, Yi; Lin, Zhiyong

    2007-06-01

    Object selection is an important technical problem in the process of map generalization. Considering creative-thinking characteristic of map generalization process, the paper bring the Rough Set theory from spatial data mine field to map generalization field, put forward a new thought for map generalization based on classification idea of Rough Set. The method of Rough Set which has the benefit on enormous data with the imperfection and non-precision character has become a new tool to make research on spatial data mining. The paper analyzes the imperfection characters of geo-spatial data processing based on Rough Set and the selection problem in the processing of map generalization with classification thought; presents the thought that map generalization is a kind of classification for map objects. The method mentioned in this paper use different spatial and attribute information as different point of view to observe the map objects. The result of the classification is ordered by the weightiness of all kinds of factors. In the end, a river objects selection test validates the rough set map generalization method mentioned in this paper.

  12. A fast method for computing the centroid of a type-2 fuzzy set.

    PubMed

    Wu, Hsin-Jung; Su, Yao-Lung; Lee, Shie-Jue

    2012-06-01

    Type reduction does the work of computing the centroid of a type-2 fuzzy set. The result is a type-1 fuzzy set from which a corresponding crisp number can then be obtained through defuzzification. Type reduction is one of the major operations involved in type-2 fuzzy inference. Therefore, making type reduction efficient is a significant task in the application of type-2 fuzzy systems. Liu introduced a horizontal slice representation, called the α-plane representation, and proposed a type-reduction method for a type-2 fuzzy set. By exploring some useful properties of the α-plane representation and of the type reduction for interval type-2 fuzzy sets, a fast method is developed for computing the centroid of a type-2 fuzzy set. The number of computations and comparisons involved is greatly reduced. Convergence in each iteration can then speed up, and type reduction can be done much more efficiently. The effectiveness of the proposed method is analyzed mathematically and demonstrated by experimental results. PMID:22180511

  13. Study of burn scar extraction automatically based on level set method using remote sensing data.

    PubMed

    Liu, Yang; Dai, Qin; Liu, Jianbo; Liu, ShiBin; Yang, Jin

    2014-01-01

    Burn scar extraction using remote sensing data is an efficient way to precisely evaluate burn area and measure vegetation recovery. Traditional burn scar extraction methodologies have no well effect on burn scar image with blurred and irregular edges. To address these issues, this paper proposes an automatic method to extract burn scar based on Level Set Method (LSM). This method utilizes the advantages of the different features in remote sensing images, as well as considers the practical needs of extracting the burn scar rapidly and automatically. This approach integrates Change Vector Analysis (CVA), Normalized Difference Vegetation Index (NDVI) and the Normalized Burn Ratio (NBR) to obtain difference image and modifies conventional Level Set Method Chan-Vese (C-V) model with a new initial curve which results from a binary image applying K-means method on fitting errors of two near-infrared band images. Landsat 5 TM and Landsat 8 OLI data sets are used to validate the proposed method. Comparison with conventional C-V model, OSTU algorithm, Fuzzy C-mean (FCM) algorithm are made to show that the proposed approach can extract the outline curve of fire burn scar effectively and exactly. The method has higher extraction accuracy and less algorithm complexity than that of the conventional C-V model. PMID:24503563

  14. A Cartesian Adaptive Level Set Method for Two-Phase Flows

    NASA Technical Reports Server (NTRS)

    Ham, F.; Young, Y.-N.

    2003-01-01

    In the present contribution we develop a level set method based on local anisotropic Cartesian adaptation as described in Ham et al. (2002). Such an approach should allow for the smallest possible Cartesian grid capable of resolving a given flow. The remainder of the paper is organized as follows. In section 2 the level set formulation for free surface calculations is presented and its strengths and weaknesses relative to the other free surface methods reviewed. In section 3 the collocated numerical method is described. In section 4 the method is validated by solving the 2D and 3D drop oscilation problem. In section 5 we present some results from more complex cases including the 3D drop breakup in an impulsively accelerated free stream, and the 3D immiscible Rayleigh-Taylor instability. Conclusions are given in section 6.

  15. Understanding client satisfaction with HIV testing and counseling services: a mixed-methods study in four African countries.

    PubMed

    Osborn, Michelle; Obermeyer, Carla Makhlouf

    2016-06-01

    This paper uses mixed methods to provide comparative evidence across four African countries and identify those aspects of the testing experience that are the most important components of clients' satisfaction with services. We analyze data from three sources: a survey of clients at health facilities that included closed-ended questions about specific services and interactions around testing; responses to open-ended questions about testing experiences that were part of the same survey; and semi-structured interviews with a subsample of respondents who described their experience of testing and being diagnosed with HIV. High levels of reported satisfaction are found in both the survey and interview. The critical factors contributing to client satisfaction included: the three C's of testing-counseling, consent, and confidentiality, client-provider interactions, convenience of location, "good services", and reliable test results. PMID:26872848

  16. A Primer-Test Centered Equating Method for Setting Cut-Off Scores

    ERIC Educational Resources Information Center

    Zhu, Weimo; Plowman, Sharon Ann; Park, Youngsik

    2010-01-01

    This study evaluated the use of a new primary field test method based on test equating to address inconsistent classification among field tests. We analyzed students' information on the Progressive Aerobic Cardiovascular Endurance Run (PACER), mile run (MR), and VO[subscript 2]max from three data sets (college: n = 94; middle school: n = 39;…

  17. A regularized Newton method for solving equilibrium programming problems with an inexactly specified set

    NASA Astrophysics Data System (ADS)

    Antipin, A. S.; Vasil'Ev, F. P.; Stukalov, A. S.

    2007-01-01

    Unstable equilibrium problems are examined in which the objective function and the set where the equilibrium point is sought are specified inexactly. A regularized Newton method, combined with penalty functions, is proposed for solving such problems, and its convergence is analyzed. A regularizing operator is constructed.

  18. An Evaluation of Methods for Setting Standards on the Essay Portion of the National Teacher Examinations.

    ERIC Educational Resources Information Center

    Busch, John Christian; Jaeger, Richard M.

    This study addressed seven questions regarding the methods used in setting passing scores on the essay subtest of the National Teacher Examinations (NTE) Communication Skills test for the North Carolina State Board of Education. North Carolina uses these tests to screen prospective applicants to teacher education programs. The judges (five college…

  19. Monitoring Reading Growth: Goal Setting, Measurement Frequency, and Methods of Evaluation

    ERIC Educational Resources Information Center

    Jenkins, Joseph; Terjeson, Kari J.

    2011-01-01

    This study examined effects of goal setting, frequency of progress monitoring, and method of evaluating progress on the number of instructional change prompts generated by reading-curriculum-based measurements (CBM). Participants were 31 high-incidence special education students in grades 2-6 selected from 8 schools. Following baseline…

  20. Commentary: A Response to Reckase's Conceptual Framework and Examples for Evaluating Standard Setting Methods

    ERIC Educational Resources Information Center

    Schulz, E. Matthew

    2006-01-01

    A look at real data shows that Reckase's psychometric theory for standard setting is not applicable to bookmark and that his simulations cannot explain actual differences between methods. It is suggested that exclusively test-centered, criterion-referenced approaches are too idealized and that a psychophysics paradigm and a theory of group…

  1. Application of Vertical Cluster Analysis Method to the Analysis of Time Dependent Biological Data Sets

    NASA Astrophysics Data System (ADS)

    Chandra, Sathees B. C.; Wang, Yao

    The purpose of this study is to apply vertical cluster analysis method to interpret and analyze habituation of the leg movement response, to different odors, in fruit flies. In most cases cluster analysis methods are used to analyze data sets, which can be classified into categories. We define this type of method as horizontal cluster analysis method. In this study, instead of dividing the data into categories, we divide the data based on different periods of time. We define this method as a vertical cluster analysis method. Here we apply vertical cluster analysis method to evaluate the habituation of leg movement responses of fruit fly, Drosophila melanogaster. The vertical cluster analyses helped us to identify hidden features of fruit fly behavior.

  2. Comparisons and Limitations of Gradient Augmented Level Set and Algebraic Volume of Fluid Methods

    NASA Astrophysics Data System (ADS)

    Anumolu, Lakshman; Ryddner, Douglas; Trujillo, Mario

    2014-11-01

    Recent numerical methods for implicit interface transport are generally presented as enjoying higher order of spatial-temporal convergence when compared to classical methods or less sophisticated approaches. However, when applied to test cases, which are designed to simulate practical industrial conditions, significant reduction in convergence is observed in higher-order methods, whereas for the less sophisticated approaches same convergence is achieved but a growth in the error norms occurs. This provides an opportunity to understand the underlying issues which causes this decrease in accuracy in both types of methods. As an example we consider the Gradient Augmented Level Set method (GALS) and a variant of the Volume of Fluid (VoF) method in our study. Results show that while both methods do suffer from a loss of accuracy, it is the higher order method that suffers more. The implication is a significant reduction in the performance advantage of the GALS method over the VoF scheme. Reasons for this lie in the behavior of the higher order derivatives, particular in situations where the level set field is highly distorted. For the VoF approach, serious spurious deformations of the interface are observed, albeit with a deceptive zero loss of mass.

  3. Online monitoring of oil film using electrical capacitance tomography and level set method

    SciTech Connect

    Xue, Q. Ma, M.; Sun, B. Y.; Cui, Z. Q.; Wang, H. X.

    2015-08-15

    In the application of oil-air lubrication system, electrical capacitance tomography (ECT) provides a promising way for monitoring oil film in the pipelines by reconstructing cross sectional oil distributions in real time. While in the case of small diameter pipe and thin oil film, the thickness of the oil film is hard to be observed visually since the interface of oil and air is not obvious in the reconstructed images. And the existence of artifacts in the reconstructions has seriously influenced the effectiveness of image segmentation techniques such as level set method. Besides, level set method is also unavailable for online monitoring due to its low computation speed. To address these problems, a modified level set method is developed: a distance regularized level set evolution formulation is extended to image two-phase flow online using an ECT system, a narrowband image filter is defined to eliminate the influence of artifacts, and considering the continuity of the oil distribution variation, the detected oil-air interface of a former image can be used as the initial contour for the detection of the subsequent frame; thus, the propagation from the initial contour to the boundary can be greatly accelerated, making it possible for real time tracking. To testify the feasibility of the proposed method, an oil-air lubrication facility with 4 mm inner diameter pipe is measured in normal operation using an 8-electrode ECT system. Both simulation and experiment results indicate that the modified level set method is capable of visualizing the oil-air interface accurately online.

  4. Online monitoring of oil film using electrical capacitance tomography and level set method

    NASA Astrophysics Data System (ADS)

    Xue, Q.; Sun, B. Y.; Cui, Z. Q.; Ma, M.; Wang, H. X.

    2015-08-01

    In the application of oil-air lubrication system, electrical capacitance tomography (ECT) provides a promising way for monitoring oil film in the pipelines by reconstructing cross sectional oil distributions in real time. While in the case of small diameter pipe and thin oil film, the thickness of the oil film is hard to be observed visually since the interface of oil and air is not obvious in the reconstructed images. And the existence of artifacts in the reconstructions has seriously influenced the effectiveness of image segmentation techniques such as level set method. Besides, level set method is also unavailable for online monitoring due to its low computation speed. To address these problems, a modified level set method is developed: a distance regularized level set evolution formulation is extended to image two-phase flow online using an ECT system, a narrowband image filter is defined to eliminate the influence of artifacts, and considering the continuity of the oil distribution variation, the detected oil-air interface of a former image can be used as the initial contour for the detection of the subsequent frame; thus, the propagation from the initial contour to the boundary can be greatly accelerated, making it possible for real time tracking. To testify the feasibility of the proposed method, an oil-air lubrication facility with 4 mm inner diameter pipe is measured in normal operation using an 8-electrode ECT system. Both simulation and experiment results indicate that the modified level set method is capable of visualizing the oil-air interface accurately online.

  5. A GPU Accelerated Discontinuous Galerkin Conservative Level Set Method for Simulating Atomization

    NASA Astrophysics Data System (ADS)

    Jibben, Zechariah J.

    This dissertation describes a process for interface capturing via an arbitrary-order, nearly quadrature free, discontinuous Galerkin (DG) scheme for the conservative level set method (Olsson et al., 2005, 2008). The DG numerical method is utilized to solve both advection and reinitialization, and executed on a refined level set grid (Herrmann, 2008) for effective use of processing power. Computation is executed in parallel utilizing both CPU and GPU architectures to make the method feasible at high order. Finally, a sparse data structure is implemented to take full advantage of parallelism on the GPU, where performance relies on well-managed memory operations. With solution variables projected into a kth order polynomial basis, a k + 1 order convergence rate is found for both advection and reinitialization tests using the method of manufactured solutions. Other standard test cases, such as Zalesak's disk and deformation of columns and spheres in periodic vortices are also performed, showing several orders of magnitude improvement over traditional WENO level set methods. These tests also show the impact of reinitialization, which often increases shape and volume errors as a result of level set scalar trapping by normal vectors calculated from the local level set field. Accelerating advection via GPU hardware is found to provide a 30x speedup factor comparing a 2.0GHz Intel Xeon E5-2620 CPU in serial vs. a Nvidia Tesla K20 GPU, with speedup factors increasing with polynomial degree until shared memory is filled. A similar algorithm is implemented for reinitialization, which relies on heavier use of shared and global memory and as a result fills them more quickly and produces smaller speedups of 18x.

  6. Online monitoring of oil film using electrical capacitance tomography and level set method.

    PubMed

    Xue, Q; Sun, B Y; Cui, Z Q; Ma, M; Wang, H X

    2015-08-01

    In the application of oil-air lubrication system, electrical capacitance tomography (ECT) provides a promising way for monitoring oil film in the pipelines by reconstructing cross sectional oil distributions in real time. While in the case of small diameter pipe and thin oil film, the thickness of the oil film is hard to be observed visually since the interface of oil and air is not obvious in the reconstructed images. And the existence of artifacts in the reconstructions has seriously influenced the effectiveness of image segmentation techniques such as level set method. Besides, level set method is also unavailable for online monitoring due to its low computation speed. To address these problems, a modified level set method is developed: a distance regularized level set evolution formulation is extended to image two-phase flow online using an ECT system, a narrowband image filter is defined to eliminate the influence of artifacts, and considering the continuity of the oil distribution variation, the detected oil-air interface of a former image can be used as the initial contour for the detection of the subsequent frame; thus, the propagation from the initial contour to the boundary can be greatly accelerated, making it possible for real time tracking. To testify the feasibility of the proposed method, an oil-air lubrication facility with 4 mm inner diameter pipe is measured in normal operation using an 8-electrode ECT system. Both simulation and experiment results indicate that the modified level set method is capable of visualizing the oil-air interface accurately online. PMID:26329232

  7. Online measuring method of the wheel set wear based on CCD and image processing

    NASA Astrophysics Data System (ADS)

    Wu, Kaihua; Zhang, Jianhua; Yan, Kuang

    2005-01-01

    The online measurement of wheel set wear parameters is important for ensuring the safety of train vehicle and increasing the reliability and efficiency of maintaining. The paper researched an automatic measuring method of wheel set parameters based on CCD and image processing. The method used precision laser displacement sensor, CCD, digital image processing and motion control technology to realize the non-contact automatic measuring of wheel set parameters. These parameters include the flange thickness, flange height, wheel diameter, rim inside distance, rim inside thickness, rim width, scotching and flaking on wheel tread. The tread and flange profile were captured using laser source and high resolution CCD sensor. The image SNR was gained through narrow band-pass optical filters which wavelength matched with laser source. In order to detect the irregular tread failures formed in running of train vehicle, the paper used precision laser displacement sensor to scan the tread and acquire the position while the wheel set was rotating. The displacement data of different positions were transformed to digital image. Then digital image processing was used to distinguish and judge the failures. The measuring accuracy of geometrical parameters, scotching depth and flaking length were 0.2mm, 0.1mm and 0.5mm respectively. The repeatability and accuracy can meet the demand of non-contact online wheel set maintaining.

  8. Benchmarking Methods and Data Sets for Ligand Enrichment Assessment in Virtual Screening

    PubMed Central

    Xia, Jie; Tilahun, Ermias Lemma; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

    2014-01-01

    Retrospective small-scale virtual screening (VS) based on benchmarking data sets has been widely used to estimate ligand enrichments of VS approaches in the prospective (i.e. real-world) efforts. However, the intrinsic differences of benchmarking sets to the real screening chemical libraries can cause biased assessment. Herein, we summarize the history of benchmarking methods as well as data sets and highlight three main types of biases found in benchmarking sets, i.e. “analogue bias”, “artificial enrichment” and “false negative”. In addition, we introduced our recent algorithm to build maximum-unbiased benchmarking sets applicable to both ligand-based and structure-based VS approaches, and its implementations to three important human histone deacetylase (HDAC) isoforms, i.e. HDAC1, HDAC6 and HDAC8. The Leave-One-Out Cross-Validation (LOO CV) demonstrates that the benchmarking sets built by our algorithm are maximum-unbiased in terms of property matching, ROC curves and AUCs. PMID:25481478

  9. An automatic method of brain tumor segmentation from MRI volume based on the symmetry of brain and level set method

    NASA Astrophysics Data System (ADS)

    Li, Xiaobing; Qiu, Tianshuang; Lebonvallet, Stephane; Ruan, Su

    2010-02-01

    This paper presents a brain tumor segmentation method which automatically segments tumors from human brain MRI image volume. The presented model is based on the symmetry of human brain and level set method. Firstly, the midsagittal plane of an MRI volume is searched, the slices with potential tumor of the volume are checked out according to their symmetries, and an initial boundary of the tumor in the slice, in which the tumor is in the largest size, is determined meanwhile by watershed and morphological algorithms; Secondly, the level set method is applied to the initial boundary to drive the curve evolving and stopping to the appropriate tumor boundary; Lastly, the tumor boundary is projected one by one to its adjacent slices as initial boundaries through the volume for the whole tumor. The experiment results are compared with hand tracking of the expert and show relatively good accordance between both.

  10. African American Suicide

    MedlinePlus

    ... accounted for 83.8% of Caucasian elderly suicides. • Firearms were the predominant method of suicide among African ... per 100,000 annually. Source: Centers for Disease Control and Prevention. National Vital Statistics System. Mortality Data. ...

  11. A mixed methods study of health and social disparities among substance-using African American/Black men who have sex with men.

    PubMed

    Buttram, Mance E; Kurtz, Steven P

    2015-03-01

    African American/Black men who have sex with men (MSM) in the U.S. experience health and social disparities at greater rates than MSM of other races/ethnicities, including HIV infection and substance use. This mixed methods paper presents: 1) a quantitative examination of health and social disparities among a sample of substance-using African American/Black MSM (N=108), compared to Caucasian/White MSM (N=250), and 2) in-depth qualitative data from a subsample of African American/Black MSM (N=21) in order to contextualize the quantitative data. Findings indicate that compared to Caucasian/White MSM, African American/Black MSM experienced a wide range of health and social disparities including: substance use and dependence; buying, trading or selling sex; educational attainment; employment; homelessness; identifying as gay; HIV status; arrest history; social support; and satisfaction with one's living situation. Qualitative data suggests that structural interventions that address homophobia and the social environment would be likely to mitigate many of the health and social disparities experienced by African American/Black MSM. PMID:25960944

  12. Why does Japan use the probability method to set design flood?

    NASA Astrophysics Data System (ADS)

    Nakamura, S.; Oki, T.

    2015-12-01

    Design flood is hypothetical flood to make flood prevention plan. In Japan, a probability method based on precipitation data is used to define the scale of design flood: Tone River, the biggest river in Japan, is 1 in 200 years, Shinano River is 1 in 150 years, and so on. It is one of important socio-hydrological issue how to set reasonable and acceptable design flood in a changing world. The method to set design flood vary among countries. Although the probability method is also used in Netherland, but the base data is water level or discharge data and the probability is 1 in 1250 years (in fresh water section). On the other side, USA and China apply the maximum flood method which set the design flood based on the historical or probable maximum flood. This cases can leads a question: "what is the reason why the method vary among countries?" or "why does Japan use the probability method?" The purpose of this study is to clarify the historical process which the probability method was developed in Japan based on the literature. In the late 19the century, the concept of "discharge" and modern river engineering were imported by Dutch engineers, and modern flood prevention plans were developed in Japan. In these plans, the design floods were set based on the historical maximum method. Although the historical maximum method had been used until World War 2, however, the method was changed to the probability method after the war because of limitations of historical maximum method under the specific socio-economic situations: (1) the budget limitation due to the war and the GHQ occupation, (2) the historical floods: Makurazaki typhoon in 1945, Kathleen typhoon in 1947, Ione typhoon in 1948, and so on, attacked Japan and broke the record of historical maximum discharge in main rivers and the flood disasters made the flood prevention projects difficult to complete. Then, Japanese hydrologists imported the hydrological probability statistics from the West to take account of

  13. Periodical capacity setting methods for make-to-order multi-machine production systems

    PubMed Central

    Altendorfer, Klaus; Hübl, Alexander; Jodlbauer, Herbert

    2014-01-01

    The paper presents different periodical capacity setting methods for make-to-order, multi-machine production systems with stochastic customer required lead times and stochastic processing times to improve service level and tardiness. These methods are developed as decision support when capacity flexibility exists, such as, a certain range of possible working hours a week for example. The methods differ in the amount of information used whereby all are based on the cumulated capacity demand at each machine. In a simulation study the methods’ impact on service level and tardiness is compared to a constant provided capacity for a single and a multi-machine setting. It is shown that the tested capacity setting methods can lead to an increase in service level and a decrease in average tardiness in comparison to a constant provided capacity. The methods using information on processing time and customer required lead time distribution perform best. The results found in this paper can help practitioners to make efficient use of their flexible capacity.

  14. Method and Basis Set Analysis of Oxorhenium(V) Complexes for Theoretical Calculations

    PubMed Central

    Demoin, Dustin Wayne; Li, Yawen; Jurisson, Silvia S.; Deakyne, Carol A.

    2012-01-01

    A variety of method and basis set combinations has been evaluated for monooxorhenium(V) complexes with N, O, P, S, Cl, and Se donor atoms. The geometries and energies obtained are compared to both high-level computations and literature structures. These calculations show that the PBE0 method outperforms the B3LYP method with respect to both structure and energetics. The combination of 6-31G** basis set on the nonmetal atoms and LANL2TZ effective core potential on the rhenium center gives reliable equilibrium structures with minimal computational resources for both model and literature compounds. Single-point energy calculations at the PBE0/LANL2TZ,6-311+G* level of theory are recommended for energetics. PMID:23087847

  15. Segmentation of cardiac cine-MR images and myocardial deformation assessment using level set methods.

    PubMed

    Chenoune, Y; Deléchelle, E; Petit, E; Goissen, T; Garot, J; Rahmouni, A

    2005-12-01

    In this paper, we present an original method to assess the deformations of the left ventricular myocardium on cardiac cine-MRI. First, a segmentation process, based on a level set method is directly applied on a 2D + t dataset to detect endocardial contours. Second, the successive segmented contours are matched using a procedure of global alignment, followed by a morphing process based on a level set approach. Finally, local measurements of myocardial deformations are derived from the previously determined matched contours. The validation step is realized by comparing our results to the measurements achieved on the same patients by an expert using the semi-automated HARP reference method on tagged MR images. PMID:16290086

  16. Accurate Adaptive Level Set Method and Sharpening Technique for Three Dimensional Deforming Interfaces

    NASA Technical Reports Server (NTRS)

    Kim, Hyoungin; Liou, Meng-Sing

    2011-01-01

    In this paper, we demonstrate improved accuracy of the level set method for resolving deforming interfaces by proposing two key elements: (1) accurate level set solutions on adapted Cartesian grids by judiciously choosing interpolation polynomials in regions of different grid levels and (2) enhanced reinitialization by an interface sharpening procedure. The level set equation is solved using a fifth order WENO scheme or a second order central differencing scheme depending on availability of uniform stencils at each grid point. Grid adaptation criteria are determined so that the Hamiltonian functions at nodes adjacent to interfaces are always calculated by the fifth order WENO scheme. This selective usage between the fifth order WENO and second order central differencing schemes is confirmed to give more accurate results compared to those in literature for standard test problems. In order to further improve accuracy especially near thin filaments, we suggest an artificial sharpening method, which is in a similar form with the conventional re-initialization method but utilizes sign of curvature instead of sign of the level set function. Consequently, volume loss due to numerical dissipation on thin filaments is remarkably reduced for the test problems

  17. Identifying outcome research methods that facilitate data collection in the behavioral healthcare setting

    SciTech Connect

    Smith, E.R.; Brooker, C.

    1996-12-31

    Outcome research is a necessary and increasingly prevalent part of any behavioral healthcare program. With the large set of available choices for beginning outcome research, it is of value to weigh the benefits and liabilities of using the various methods. This paper reviews methods for deciding what variables to measure, types of measures and methods for using them, and sources of tools that allow for data processing, analysis, and presentation. We will also address the organizational cultural issues that influence success and failure in the outcome research process. Finally, the value of simply beginning the research process will be emphasized.

  18. A Novel Fractal Coding Method Based on M-J Sets

    PubMed Central

    Sun, Yuanyuan; Xu, Rudan; Chen, Lina; Kong, Ruiqing; Hu, Xiaopeng

    2014-01-01

    In this paper, we present a novel fractal coding method with the block classification scheme based on a shared domain block pool. In our method, the domain block pool is called dictionary and is constructed from fractal Julia sets. The image is encoded by searching the best matching domain block with the same BTC (Block Truncation Coding) value in the dictionary. The experimental results show that the scheme is competent both in encoding speed and in reconstruction quality. Particularly for large images, the proposed method can avoid excessive growth of the computational complexity compared with the traditional fractal coding algorithm. PMID:25010686

  19. Astronomy for African development

    NASA Astrophysics Data System (ADS)

    Govender, Kevindran

    2011-06-01

    In recent years there have been a number of efforts across Africa to develop the field of astronomy as well as to reap benefit from astronomy for African people. This presentation will discuss the case of the SALT (Southern African Large Telescope) Collateral Benefits Programme (SCBP) which was set up to ensure societal benefit from astronomy. With African society as the target, the SCBP has embarked on various projects from school level education to public understanding of science to socio-economic development, the latter mainly being felt in the rural communities surrounding the South African Astronomical Observatory (home to SALT). A development plan for ``Astronomy in Africa'' will also be discussed. This plan has been drawn up with input from all over Africa and themed ``Astronomy for Education''. The Africa case stands as a good example for the IYA cornerstone project ``Developing Astronomy Globally'' which focuses on developing regions.

  20. Using novel methods to examine stress among HIV-positive African American men who have sex with men and women.

    PubMed

    Glover, Dorie A; Williams, John K; Kisler, Kimberly A

    2013-06-01

    Biomarker composites (BCs) that objectively quantify psychosocial stress independent of self report could help to identify those at greatest risk for negative health outcomes and elucidate mechanisms of stress-related processes. Here, BCs are examined in the context of existing disease progression among HIV-positive African American men who have sex with men and women (MSMW) with high stress histories, including childhood sexual abuse. Participants (N = 99) collected 12-h overnight and morning urine samples for assay of cortisol and catecholamines (primary BC) and neopterin (an indicator of HIV disease progression). Data on cumulative psychosocial trauma history (severity, types, frequency, age at first incident), posttraumatic stress disorder (PTSD) symptoms, sexual risk behaviors, and a secondary BC consisting of routine health indicators (heart rate, blood pressure, body mass index, waist-to-hip ratio) were also collected. Lifetime trauma exposure was highly pervasive and significantly greater among those meeting a standard cutoff for PTSD caseness (24 %). After controlling for HIV factors (neopterin levels and years with disease), PTSD was a significant (p < .05) predictor of the primary, but not secondary BC. Those with PTSD also had significantly more sexual partners, sex without a condom, and exchange sex for money or drugs than those without PTSD. Specific trauma characteristics predicted PTSD severity and caseness independently and uniquely in regression models (p's < .05-.001). A primary BC appears sensitive to cumulative trauma burden and PTSD in HIV-positive African American MSMW, providing support for the use of BCs to quantify psychosocial stress and inform novel methods for examining mechanisms of stress influenced health behaviors and disease outcomes in at-risk populations. PMID:22538773

  1. Hard Bigotry, Low Expectations and Soft Support: Educating American African Boys in the United States with the Warrior Method

    ERIC Educational Resources Information Center

    Winbush, Raymond A.

    2013-01-01

    Educating American Africans boys has been a mixture of political rhetoric, educational pedagogy, and historical neglect. Although American African educators have produced several models for effectively educating Black boys, most of them are dismissed as too "radical" by White researchers who have little understanding or experience in…

  2. Teaching Them All: An Exploratory Mixed Methods Study of African American Students' Perceptions of Their Middle School's Culture

    ERIC Educational Resources Information Center

    Hankerson, Henry

    2009-01-01

    Research indicates school culture impacts student achievement. At Teach Them All Middle School (TTA), an achievement gap exists between African American and White students. The purpose of the current study was to examine the perceptions of African American students concerning the school culture at TTA. The research questions explored the…

  3. Acceptability of a Community-Based Outreach HIV-Testing Intervention Using Oral Fluid Collection Devices and Web-Based HIV Test Result Collection Among Sub-Saharan African Migrants: A Mixed-Method Study

    PubMed Central

    Manirankunda, Lazare; Platteau, Tom; Albers, Laura; Fransen, Katrien; Vermoesen, Tine; Namanya, Fiona; Nöstlinger, Christiana

    2016-01-01

    fluid collection devices were well accepted mainly because sub-Saharan African migrants dislike blood taking. For some participants, the method raised concerns about HIV transmission via saliva. The combination of information sessions, testimonies, and oral fluid collection devices was perceived as effectively reducing thresholds to participation. Acceptability of the intervention differed between individual participants and settings. Acceptance was higher among women, in churches and settings where community leaders were engaged in HIV awareness raising. Higher preventive outcomes were observed in settings with lower acceptance. The presence of the intervention team visualized the magnitude of the HIV epidemic to the public and promoted HIV testing uptake at large, for example, those who declined indicated they would take up testing later. Conclusions When accompanied by tailored provision of information, outreach HIV testing interventions adopting a community-based approach and innovative methods such as Web-based result collection and oral fluid collection devices are acceptable and reduce thresholds for HIV testing uptake. The swab2know intervention was able to reach sub-Saharan African migrants at risk of HIV infection, and with limited access to regular HIV testing. Among nontesters, the intervention contributed to awareness raising and therefore has a place in a multipronged HIV test promotion strategy. PMID:27493067

  4. Evidence-based vaccination strategies in obstetrics and gynecology settings: Current practices and methods for assessment.

    PubMed

    O'Leary, Sean T; Pyrzanowski, Jennifer; Brewer, Sarah E; Dickinson, L Miriam; Dempsey, Amanda F

    2016-04-01

    Obstetrician-gynecologists have the potential to play an important role in the delivery of immunizations to women. However, despite national recommendations, immunization rates among pregnant women and adults in general remain low. Pragmatic immunization delivery trials are needed to demonstrate how best to deliver vaccines in such settings. We report the development and implementation of 2 novel methodologies for immunization delivery research and quality improvement in such settings. The first was the development and application of a 47-point Immunization Delivery Scale that formally assessed variability among practices in their engagement in a variety of evidence-based practices for improving immunization rates. The second was a covariate-constrained randomization technique - a method for achieving balance between study arms in cluster-randomized trials that is especially applicable to pragmatic trials.. To best achieve meaningful and interpretable findings, we recommend use of these or similar techniques in future immunization research and quality improvement projects in OB/GYN settings. PMID:26829978

  5. Vascular Tree Segmentation in Medical Images Using Hessian-Based Multiscale Filtering and Level Set Method

    PubMed Central

    Jin, Jiaoying; Yang, Linjun; Zhang, Xuming

    2013-01-01

    Vascular segmentation plays an important role in medical image analysis. A novel technique for the automatic extraction of vascular trees from 2D medical images is presented, which combines Hessian-based multiscale filtering and a modified level set method. In the proposed algorithm, the morphological top-hat transformation is firstly adopted to attenuate background. Then Hessian-based multiscale filtering is used to enhance vascular structures by combining Hessian matrix with Gaussian convolution to tune the filtering response to the specific scales. Because Gaussian convolution tends to blur vessel boundaries, which makes scale selection inaccurate, an improved level set method is finally proposed to extract vascular structures by introducing an external constrained term related to the standard deviation of Gaussian function into the traditional level set. Our approach was tested on synthetic images with vascular-like structures and 2D slices extracted from real 3D abdomen magnetic resonance angiography (MRA) images along the coronal plane. The segmentation rates for synthetic images are above 95%. The results for MRA images demonstrate that the proposed method can extract most of the vascular structures successfully and accurately in visualization. Therefore, the proposed method is effective for the vascular tree extraction in medical images. PMID:24348738

  6. Dynamic multi-source X-ray tomography using a spacetime level set method

    NASA Astrophysics Data System (ADS)

    Niemi, Esa; Lassas, Matti; Kallonen, Aki; Harhanen, Lauri; Hämäläinen, Keijo; Siltanen, Samuli

    2015-06-01

    A novel variant of the level set method is introduced for dynamic X-ray tomography. The target is allowed to change in time while being imaged by one or several source-detector pairs at a relatively high frame-rate. The algorithmic approach is motivated by the results in [22], showing that the modified level set method can tolerate highly incomplete projection data in stationary tomography. Furthermore, defining the level set function in spacetime enforces temporal continuity in the dynamic tomography context considered here. The tomographic reconstruction is found as a minimizer of a nonlinear functional. The functional contains a regularization term penalizing the L2 norms of up to n derivatives of the reconstruction. The case n = 1 is shown to be equivalent to a convex Tikhonov problem that has a unique minimizer. For n ≥ 2 the existence of a minimizer is proved under certain assumptions on the signal-to-noise ratio and the size of the regularization parameter. Numerical examples with both simulated and measured dynamic X-ray data are included, and the proposed method is found to yield reconstructions superior to standard methods such as FBP or non-negativity constrained Tikhonov regularization and favorably comparable to those of total variation regularization. Furthermore, the methodology can be adapted to a wide range of measurement arrangements with one or more X-ray sources.

  7. TOGETHER Project to Increase Understanding of the HIV Epidemic Among Sub-Saharan African Migrants: Protocol of Community-Based Participatory Mixed-Method Studies

    PubMed Central

    Vuylsteke, Bea; Manirankunda, Lazare; Deblonde, Jessika; Kint, Ilse; Namanya, Fiona; Fransen, Katrien; Colebunders, Robert; Laga, Marie; Adobea, Dorothy; Nöstlinger, Christiana

    2016-01-01

    Background Sub-Saharan African Migrants (SAM) are the second largest group affected by HIV/AIDS in Belgium and the rest of Western Europe. Increasing evidence shows that, more than previously thought, SAM are acquiring HIV in their host countries. This calls for a renewed focus on primary prevention. Yet, knowledge on the magnitude of the HIV epidemic among SAM (HIV prevalence estimates and proportions of undiagnosed HIV infections) and underlying drivers are scarce and limit the development of such interventions. Objective By applying a community-based participatory and mixed-methods approach, the TOGETHER project aims to deepen our understanding of HIV transmission dynamics, as well as inform future primary prevention interventions for this target group. Methods The TOGETHER project consists of a cross-sectional study to assess HIV prevalence and risk factors among SAM visiting community settings in Antwerp city, Belgium, and links an anonymous electronic self-reported questionnaire to oral fluid samples. Three formative studies informed this method: (1) a social mapping of community settings using an adaptation of the PLACE method; (2) a multiple case study aiming to identify factors that increase risk and vulnerability for HIV infection by triangulating data from life history interviews, lifelines, and patient files; and (3) an acceptability and feasibility study of oral fluid sampling in community settings using participant observations. Results Results have been obtained from 4 interlinked studies and will be described in future research. Conclusions Combining empirically tested and innovative epidemiological and social science methods, this project provides the first HIV prevalence estimates for a representative sample of SAM residing in a West European city. By triangulating qualitative and quantitative insights, the project will generate an in-depth understanding of the factors that increase risk and vulnerability for HIV infection among SAM. Based on this

  8. Coresets vs clustering: comparison of methods for redundancy reduction in very large white matter fiber sets

    NASA Astrophysics Data System (ADS)

    Alexandroni, Guy; Zimmerman Moreno, Gali; Sochen, Nir; Greenspan, Hayit

    2016-03-01

    Recent advances in Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) of white matter in conjunction with improved tractography produce impressive reconstructions of White Matter (WM) pathways. These pathways (fiber sets) often contain hundreds of thousands of fibers, or more. In order to make fiber based analysis more practical, the fiber set needs to be preprocessed to eliminate redundancies and to keep only essential representative fibers. In this paper we demonstrate and compare two distinctive frameworks for selecting this reduced set of fibers. The first framework entails pre-clustering the fibers using k-means, followed by Hierarchical Clustering and replacing each cluster with one representative. For the second clustering stage seven distance metrics were evaluated. The second framework is based on an efficient geometric approximation paradigm named coresets. Coresets present a new approach to optimization and have huge success especially in tasks requiring large computation time and/or memory. We propose a modified version of the coresets algorithm, Density Coreset. It is used for extracting the main fibers from dense datasets, leaving a small set that represents the main structures and connectivity of the brain. A novel approach, based on a 3D indicator structure, is used for comparing the frameworks. This comparison was applied to High Angular Resolution Diffusion Imaging (HARDI) scans of 4 healthy individuals. We show that among the clustering based methods, that cosine distance gives the best performance. In comparing the clustering schemes with coresets, Density Coreset method achieves the best performance.

  9. Clustering and training set selection methods for improving the accuracy of quantitative laser induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Anderson, Ryan B.; Bell, James F., III; Wiens, Roger C.; Morris, Richard V.; Clegg, Samuel M.

    2012-04-01

    We investigated five clustering and training set selection methods to improve the accuracy of quantitative chemical analysis of geologic samples by laser induced breakdown spectroscopy (LIBS) using partial least squares (PLS) regression. The LIBS spectra were previously acquired for 195 rock slabs and 31 pressed powder geostandards under 7 Torr CO2 at a stand-off distance of 7 m at 17 mJ per pulse to simulate the operational conditions of the ChemCam LIBS instrument on the Mars Science Laboratory Curiosity rover. The clustering and training set selection methods, which do not require prior knowledge of the chemical composition of the test-set samples, are based on grouping similar spectra and selecting appropriate training spectra for the partial least squares (PLS2) model. These methods were: (1) hierarchical clustering of the full set of training spectra and selection of a subset for use in training; (2) k-means clustering of all spectra and generation of PLS2 models based on the training samples within each cluster; (3) iterative use of PLS2 to predict sample composition and k-means clustering of the predicted compositions to subdivide the groups of spectra; (4) soft independent modeling of class analogy (SIMCA) classification of spectra, and generation of PLS2 models based on the training samples within each class; (5) use of Bayesian information criteria (BIC) to determine an optimal number of clusters and generation of PLS2 models based on the training samples within each cluster. The iterative method and the k-means method using 5 clusters showed the best performance, improving the absolute quadrature root mean squared error (RMSE) by ~ 3 wt.%. The statistical significance of these improvements was ~ 85%. Our results show that although clustering methods can modestly improve results, a large and diverse training set is the most reliable way to improve the accuracy of quantitative LIBS. In particular, additional sulfate standards and specifically fabricated

  10. Applying a fuzzy-set-based method for robust estimation of coupling loss factors

    NASA Astrophysics Data System (ADS)

    Nunes, R. F.; Ahmida, K. M.; Arruda, J. R. F.

    2007-10-01

    Finite element models have been used by many authors to provide accurate estimations of coupling loss factors. Although much progress has been achieved in this area, little attention has been paid to the influence of uncertain parameters in the finite element model used to estimate these factors. It is well known that, in the mid-frequency range, uncertainty is a major issue. In this context, a spectral element method combined with a special implementation of a fuzzy-set-based method, which is called the transformation method, is proposed as an alternative to compute coupling loss factors. The proposed technique is applied to a frame-type junction, which can consist of two beams connected at an arbitrary angle. In this context, two problems are investigated. In the first one, the influence of the confidence intervals of the coupling loss factors on the estimated energy envelopes assuming a unit power input is considered. In the other problem the influence of the envelope of the input power obtained considering the confidence intervals of the coupling loss factors is also taken into account. The estimates of the intervals are obtained by using the spectral element method combined with a fuzzy-set-based method. Results using a Monte Carlo analysis for the estimation of the coupling loss factors under the influence of uncertain parameters are shown for comparison and verification of the fuzzy method.

  11. A mass conserving level set method for detailed numerical simulation of liquid atomization

    SciTech Connect

    Luo, Kun; Shao, Changxiao; Yang, Yue; Fan, Jianren

    2015-10-01

    An improved mass conserving level set method for detailed numerical simulations of liquid atomization is developed to address the issue of mass loss in the existing level set method. This method introduces a mass remedy procedure based on the local curvature at the interface, and in principle, can ensure the absolute mass conservation of the liquid phase in the computational domain. Three benchmark cases, including Zalesak's disk, a drop deforming in a vortex field, and the binary drop head-on collision, are simulated to validate the present method, and the excellent agreement with exact solutions or experimental results is achieved. It is shown that the present method is able to capture the complex interface with second-order accuracy and negligible additional computational cost. The present method is then applied to study more complex flows, such as a drop impacting on a liquid film and the swirling liquid sheet atomization, which again, demonstrates the advantages of mass conservation and the capability to represent the interface accurately.

  12. Parallel computation of level set method for 500 Hz visual servo control

    NASA Astrophysics Data System (ADS)

    Fei, Xianfeng; Igarashi, Yasunobu; Hashimoto, Koichi

    2008-11-01

    We propose a 2D microorganism tracking system using a parallel level set method and a column parallel vision system (CPV). This system keeps a single microorganism in the middle of the visual field under a microscope by visual servoing an automated stage. We propose a new energy function for the level set method. This function constrains an amount of light intensity inside the detected object contour to control the number of the detected objects. This algorithm is implemented in CPV system and computational time for each frame is 2 [ms], approximately. A tracking experiment for about 25 s is demonstrated. Also we demonstrate a single paramecium can be kept tracking even if other paramecia appear in the visual field and contact with the tracked paramecium.

  13. A method of hidden Markov model optimization for use with geophysical data sets

    NASA Technical Reports Server (NTRS)

    Granat, R. A.

    2003-01-01

    Geophysics research has been faced with a growing need for automated techniques with which to process large quantities of data. A successful tool must meet a number of requirements: it should be consistent, require minimal parameter tuning, and produce scientifically meaningful results in reasonable time. We introduce a hidden Markov model (HMM)-based method for analysis of geophysical data sets that attempts to address these issues.

  14. A Condition-Enumeration Tree method for mining biclusters from DNA microarray data sets.

    PubMed

    Chen, Jiun-Rung; Chang, Ye-In

    2009-07-01

    Biclustering, which performs simultaneous clustering of rows (e.g., genes) and columns (e.g., conditions), has proved of great value for finding interesting patterns from microarray data. To find biclusters, a model called pCluster was proposed. A pCluster consists of a set of genes and a set of conditions, where the expression levels of these genes have a similar variation under these conditions. Based on this model, most of the previous methods need to compute MDSs (maximum dimension sets) for every two genes in the microarray data. Since the number of genes is far larger than the number of conditions, this step is inefficient. Another method called MicroCluster was proposed. This method does not compute MDSs for every two genes, and transforms the problem into a graph problem. However, it needs to solve the Maximal Clique problem, which is NP-Complete. To avoid the above disadvantages, in this paper, we propose a new method, CE-Tree (Condition-Enumeration Tree), for finding pClusters. Instead of generating MDSs for every two genes, we generate only MDSs for every two conditions. Then, based only on these MDSs, we expand the CE-Tree in a special local breadth-first within global depth-first manner to efficiently find all pClusters. We also utilize the idea of the traditional hash join approach to efficiently support the CE-Tree. From the simulation results, we show that the CE-Tree method could find pClusters more efficiently than those previous methods. PMID:19393714

  15. Ersatz function method for minimizing a finite-valued function on a compact set

    NASA Astrophysics Data System (ADS)

    Ryabikov, A. I.

    2014-02-01

    A method is proposed for solving optimization problems with continuous variables and a function taking a large finite set of values. Problems of this type arise in the multicriteria construction of a control rule for a discrete-time dynamical system whose performance criteria coincide with the number of violations of requirements imposed on the system. The rule depends on a finite set of parameters whose set of admissible values defines a collection of admissible control rules. An example is the problem of choosing a control rule for a cascade of reservoirs. The optimization method is based on solving a modified problem in which the original function is replaced by a continuous ersatz function. A theorem on the relation between the average-minimal values of the original and ersatz functions is proved. Optimization problems are solved with power-law ersatz functions, and the influence exerted by the exponent on the quality of the solution is determined. It is experimentally shown that the solutions produced by the method are of fairly high quality.

  16. Comparing simple root phenotyping methods on a core set of rice genotypes.

    PubMed

    Shrestha, R; Al-Shugeairy, Z; Al-Ogaidi, F; Munasinghe, M; Radermacher, M; Vandenhirtz, J; Price, A H

    2014-05-01

    Interest in belowground plant growth is increasing, especially in relation to arguments that shallow-rooted cultivars are efficient at exploiting soil phosphorus while deep-rooted ones will access water at depth. However, methods for assessing roots in large numbers of plants are diverse and direct comparisons of methods are rare. Three methods for measuring root growth traits were evaluated for utility in discriminating rice cultivars: soil-filled rhizotrons, hydroponics and soil-filled pots whose bottom was sealed with a non-woven fabric (a potential method for assessing root penetration ability). A set of 38 rice genotypes including the OryzaSNP set of 20 cultivars, additional parents of mapping populations and products of marker-assisted selection for root QTLs were assessed. A novel method of image analysis for assessing rooting angles from rhizotron photographs was employed. The non-woven fabric was the easiest yet least discriminatory method, while the rhizotron was highly discriminatory and allowed the most traits to be measured but required more than three times the labour of the other methods. The hydroponics was both easy and discriminatory, allowed temporal measurements, but is most likely to suffer from artefacts. Image analysis of rhizotrons compared favourably to manual methods for discriminating between cultivars. Previous observations that cultivars from the indica subpopulation have shallower rooting angles than aus or japonica cultivars were confirmed in the rhizotrons, and indica and temperate japonicas had lower maximum root lengths in rhizotrons and hydroponics. It is concluded that rhizotrons are the preferred method for root screening, particularly since root angles can be assessed. PMID:24015692

  17. Setting health research priorities using the CHNRI method: IV. Key conceptual advances

    PubMed Central

    Rudan, Igor

    2016-01-01

    Introduction Child Health and Nutrition Research Initiative (CHNRI) started as an initiative of the Global Forum for Health Research in Geneva, Switzerland. Its aim was to develop a method that could assist priority setting in health research investments. The first version of the CHNRI method was published in 2007–2008. The aim of this paper was to summarize the history of the development of the CHNRI method and its key conceptual advances. Methods The guiding principle of the CHNRI method is to expose the potential of many competing health research ideas to reduce disease burden and inequities that exist in the population in a feasible and cost–effective way. Results The CHNRI method introduced three key conceptual advances that led to its increased popularity in comparison to other priority–setting methods and processes. First, it proposed a systematic approach to listing a large number of possible research ideas, using the “4D” framework (description, delivery, development and discovery research) and a well–defined “depth” of proposed research ideas (research instruments, avenues, options and questions). Second, it proposed a systematic approach for discriminating between many proposed research ideas based on a well–defined context and criteria. The five “standard” components of the context are the population of interest, the disease burden of interest, geographic limits, time scale and the preferred style of investing with respect to risk. The five “standard” criteria proposed for prioritization between research ideas are answerability, effectiveness, deliverability, maximum potential for disease burden reduction and the effect on equity. However, both the context and the criteria can be flexibly changed to meet the specific needs of each priority–setting exercise. Third, it facilitated consensus development through measuring collective optimism on each component of each research idea among a larger group of experts using a simple

  18. Towards a Norm in South African Englishes.

    ERIC Educational Resources Information Center

    van der Walt, Johann L.; van Rooy, Bertus

    2002-01-01

    Investigates the perception and application of the norm in South African English with specific reference to Black South African English. Hypothesizes that South African English is in the hibernation and expansion phase. Three sets of data are presented and analyzed. (Author/VWL)

  19. Approaches, tools and methods used for setting priorities in health research in the 21st century

    PubMed Central

    Yoshida, Sachiyo

    2016-01-01

    Background Health research is difficult to prioritize, because the number of possible competing ideas for research is large, the outcome of research is inherently uncertain, and the impact of research is difficult to predict and measure. A systematic and transparent process to assist policy makers and research funding agencies in making investment decisions is a permanent need. Methods To obtain a better understanding of the landscape of approaches, tools and methods used to prioritize health research, I conducted a methodical review using the PubMed database for the period 2001–2014. Results A total of 165 relevant studies were identified, in which health research prioritization was conducted. They most frequently used the CHNRI method (26%), followed by the Delphi method (24%), James Lind Alliance method (8%), the Combined Approach Matrix (CAM) method (2%) and the Essential National Health Research method (<1%). About 3% of studies reported no clear process and provided very little information on how priorities were set. A further 19% used a combination of expert panel interview and focus group discussion (“consultation process”) but provided few details, while a further 2% used approaches that were clearly described, but not established as a replicable method. Online surveys that were not accompanied by face–to–face meetings were used in 8% of studies, while 9% used a combination of literature review and questionnaire to scrutinise the research options for prioritization among the participating experts. Conclusion The number of priority setting exercises in health research published in PubMed–indexed journals is increasing, especially since 2010. These exercises are being conducted at a variety of levels, ranging from the global level to the level of an individual hospital. With the development of new tools and methods which have a well–defined structure – such as the CHNRI method, James Lind Alliance Method and Combined Approach Matrix – it is

  20. New Approach for Setting a Management Criterion in Microbiological Monitoring Using Rapid Microbiological Methods.

    PubMed

    Miyashita, Noe; Tanaka, Makoto; Gotoda, Ryusuke

    2015-01-01

    The application of rapid microbiological methods (RMM) to bacterial monitoring in pharmaceutical manufacturing processes is now a key topic, since timely microbiological data are critical for product release, continuous process improvement and quality control. An automated, highly sensitive detection system has been developed which can measure the amount of ATP in a sample in 2 h with one hundredfold more sensitive than the conventional ATP method. One of the major subjects for adoption and implementation of RMM is how to set the criterion value for practical microbial control. This value was conventionally been set by experimental rule and indicated as the number of colonies counted after incubation in a particular medium. We have adopted a new approach to set a criterion value which enables assessment in whether the status of the object is normal or not. By setting this criterion value, it is possible to conduct the microbiological control with the intended probability of false-positive and false-negative. In this approach the probability distribution model of the measurement value of each object in a normal status has been established by performing repetitive measurement of each object. We have suggested and verified the probability distribution form of the ATP measurement value using measurement data of the standard bacterial solution of Staphylococcus aureus. The theoretical value of the model was in good agreement with the actual measured value. The results suggest it is possible to set an applicable management criterion value using this model and to conduct new microbiological monitoring using RMM. PMID:26521822

  1. Developing core outcomes sets: methods for identifying and including patient-reported outcomes (PROs)

    PubMed Central

    2014-01-01

    Background Synthesis of patient-reported outcome (PRO) data is hindered by the range of available PRO measures (PROMs) composed of multiple scales and single items with differing terminology and content. The use of core outcome sets, an agreed minimum set of outcomes to be measured and reported in all trials of a specific condition, may improve this issue but methods to select core PRO domains from the many available PROMs are lacking. This study examines existing PROMs and describes methods to identify health domains to inform the development of a core outcome set, illustrated with an example. Methods Systematic literature searches identified validated PROMs from studies evaluating radical treatment for oesophageal cancer. PROM scale/single item names were recorded verbatim and the frequency of similar names/scales documented. PROM contents (scale components/single items) were examined for conceptual meaning by an expert clinician and methodologist and categorised into health domains. A patient advocate independently checked this categorisation. Results Searches identified 21 generic and disease-specific PROMs containing 116 scales and 32 single items with 94 different verbatim names. Identical names for scales were repeatedly used (for example, ‘physical function’ in six different measures) and others were similar (overlapping face validity) although component items were not always comparable. Based on methodological, clinical and patient expertise, 606 individual items were categorised into 32 health domains. Conclusion This study outlines a methodology for identifying candidate PRO domains from existing PROMs to inform a core outcome set to use in clinical trials. PMID:24495582

  2. Cloning of complete genome sets of six dsRNA viruses using an improved cloning method for large dsRNA genes.

    PubMed

    Potgieter, A C; Steele, A D; van Dijk, A A

    2002-09-01

    Cloning full-length large (>3 kb) dsRNA genome segments from small amounts of dsRNA has thus far remained problematic. Here, a single-primer amplification sequence-independent dsRNA cloning procedure was perfected for large genes and tailored for routine use to clone complete genome sets or individual genes. Nine complete viral genome sets were amplified by PCR, namely those of two human rotaviruses, two African horsesickness viruses (AHSV), two equine encephalosis viruses (EEV), one bluetongue virus (BTV), one reovirus and bacteriophage Phi12. Of these amplified genomes, six complete genome sets were cloned for viruses with genes ranging in size from 0.8 to 6.8 kb. Rotavirus dsRNA was extracted directly from stool samples. Co-expressed EEV VP3 and VP7 assembled into core-like particles that have typical orbivirus capsomeres. This work presents the first EEV sequence data and establishes that EEV genes have the same conserved termini (5' GUU and UAC 3') and coding assignment as AHSV and BTV. To clone complete genome sets, one-tube reactions were developed for oligo-ligation, cDNA synthesis and PCR amplification. The method is simple and efficient compared to other methods. Complete genomes can be cloned from as little as 1 ng dsRNA and a considerably reduced number of PCR cycles (22-30 cycles compared to 30-35 of other methods). This progress with cloning large dsRNA genes is important for recombinant vaccine development and determination of the role of terminal sequences for replication and gene expression. PMID:12185276

  3. African American Preschoolers' Language, Emergent Literacy Skills, and Use of African American English: A Complex Relation

    ERIC Educational Resources Information Center

    Connor, Carol McDonald; Craig, Holly K.

    2006-01-01

    Purpose: This study examined the relation between African American preschoolers' use of African American English (AAE) and their language and emergent literacy skills in an effort to better understand the perplexing and persistent difficulties many African American children experience learning to read proficiently. Method: African American…

  4. Set-theoretic methods in robust detection and isolation of sensor faults

    NASA Astrophysics Data System (ADS)

    Xu, Feng; Puig, Vicenç; Ocampo-Martinez, Carlos; Olaru, Sorin; Stoican, Florin

    2015-10-01

    This paper proposes a sensorfault detection and isolation (FDI) approach based on interval observers and invariant sets. In fault detection (FD), both interval observer-based and invariant set-based mechanisms are used to provide real-time fault alarms. In fault isolation (FI), the proposed approach also uses these two different mechanisms. The former, based on interval observers, aims to isolate faults during the transient-state operation induced by faults. If the former does not succeed, the latter, based on both interval observers and invariant sets, is started to guarantee FI after the system enters into steady state. Besides, a collection of invariant set-based FDI conditions are established by using all available system-operating information provided by all interval observers. In order to reduce computational complexity, a method to remove all available but redundant/unnecessary system-operating information is incorporated into this approach. If the considered faults satisfy the proposed FDI conditions, it can be guaranteed that they are detectable and isolable after their occurrences. This paper concludes with a case study based on a subsystem of a wind turbine benchmark, which can illustrate the effectiveness of this FDI technique.

  5. Method development for impurity profiling in SFC: The selection of a dissimilar set of stationary phases.

    PubMed

    Galea, Charlene; Mangelings, Debby; Heyden, Yvan Vander

    2015-01-01

    Supercritical fluid chromatography (SFC) is drawing considerable interest as separation technique in the pharmaceutical industry. The technique is already well established in chiral separations both analytically and on a preparative scale. The use of SFC as a technique for drug impurity profiling is examined here. To define starting conditions in method development for drug impurity profiling, a set of dissimilar stationary phases is screened in parallel. The possibility to select a set of dissimilar columns using the retention factors (k-values) for a set of 64 drugs measured on 27 columns in SFC was examined. Experiments were carried out at a back-pressure of 150 bar and 25 °C with a mobile phase consisting of CO2 and methanol with 0.1% isopropylamine (5-40% over 10 min) at a flow rate of 3 mL/min. These k-values were then used to calculate correlation coefficients on the one hand and to perform a principal component analysis on the other. The Kennard and Stone algorithm, besides dendrograms and correlation-coefficient colour maps were used to select a set of 6 dissimilar stationary phases. The stationary phase characterization results from this study were compared to those from previous studies found in the literature. Retention mechanisms for compounds possessing different properties were also evaluated. The dissimilarity of the selected subset of 6 stationary phases was validated using mixtures of compounds with similar properties and structures, as one can expect in a drug impurity profile. PMID:25630237

  6. Improved semen collection method for wild felids: urethral catheterization yields high sperm quality in African lions (Panthera leo).

    PubMed

    Lueders, I; Luther, I; Scheepers, G; van der Horst, G

    2012-08-01

    For wild and domestic felids, electroejaculation (EE) is the most common semen collection method. However, the equipment is expensive, there is a risk of urine contamination and animals usually show strong muscular contraction despite general anesthesia. Accordingly, we tested the feasibility of a different approach using urethral catheterization (UC) in seven African lions, previously described for domestic cats only. After general anesthesia with the α2-agonist medetomidine (which also stimulates semen release into the urethra) and ketamine, a transrectal ultrasound was performed to locate the prostate. A commercial dog urinary catheter (2.6 or 3.3 mm in diameter) was advanced approximately 30 cm into the urethra to allow semen collection into the lumen of the catheter by capillary forces. After retraction, sperm volumes between of 422.86 ± 296.07 μl yielded motility of 88.83 ± 13.27% (mean ± SD) with a mean sperm concentration of 1.94 × 10(9)/ml. Here we describe a simple, field friendly and effective method to attain highly concentrated semen samples with excellent motility in lions and potentially other wild felid species as an alternative to electroejaculation. PMID:22538007

  7. A variational level set method for the topology optimization of steady-state Navier Stokes flow

    NASA Astrophysics Data System (ADS)

    Zhou, Shiwei; Li, Qing

    2008-12-01

    The smoothness of topological interfaces often largely affects the fluid optimization and sometimes makes the density-based approaches, though well established in structural designs, inadequate. This paper presents a level-set method for topology optimization of steady-state Navier-Stokes flow subject to a specific fluid volume constraint. The solid-fluid interface is implicitly characterized by a zero-level contour of a higher-order scalar level set function and can be naturally transformed to other configurations as its host moves. A variational form of the cost function is constructed based upon the adjoint variable and Lagrangian multiplier techniques. To satisfy the volume constraint effectively, the Lagrangian multiplier derived from the first-order approximation of the cost function is amended by the bisection algorithm. The procedure allows evolving initial design to an optimal shape and/or topology by solving the Hamilton-Jacobi equation. Two classes of benchmarking examples are presented in this paper: (1) periodic microstructural material design for the maximum permeability; and (2) topology optimization of flow channels for minimizing energy dissipation. A number of 2D and 3D examples well demonstrated the feasibility and advantage of the level-set method in solving fluid-solid shape and topology optimization problems.

  8. Methods for Comparing Nutrients in Beebread Made by Africanized and European Honey Bees and the Effects on Hemolymph Protein Titers

    PubMed Central

    Degrandi-Hoffman, Gloria; Eckholm, Bruce; Huang, Ming

    2015-01-01

    Honey bees obtain nutrients from pollen they collect and store in the hive as beebread. We developed methods to control the pollen source that bees collect and convert to beebread by placing colonies in a specially constructed enclosed flight area. Methods were developed to analyze the protein and amino acid composition of the pollen and beebread. We also describe how consumption of the beebread was measured and methods used to determine adult worker bee hemolymph protein titers after feeding on beebread for 4, 7 and 11 days after emergence. Methods were applied to determine if genotype affects the conversion of pollen to beebread and the rate that bees consume and acquire protein from it. Two subspecies (European and Africanized honey bees; EHB and AHB respectively) were provided with the same pollen source. Based on the developed methods, beebread made by both subspecies had lower protein concentrations and pH values than the pollen. In general, amino acid concentrations in beebread made by either EHB or AHB were similar and occurred at higher levels in beebread than in pollen. Both AHB and EHB consumed significantly more of the beebread made by AHB than by EHB. Though EHB and AHB consumed similar amounts of each type of beebread, hemolymph protein concentrations in AHB were higher than in EHB. Differences in protein acquisition between AHB and EHB might reflect environmental adaptations related to the geographic region where each subspecies evolved. These differences could contribute to the successful establishment of AHB populations in the New World because of the effects on brood rearing and colony growth. PMID:25867246

  9. DIETARY ASSESSMENT IN AFRICAN AMERICANS: METHODS USED IN THE JACKSON HEART STUDY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: The dietary assessment methods used in the Jackson Heart Study (JHS) with the entire cohort and a subset of the cohort who participated in a diet and physical activity substudy (DPASS) are reported. These methods were employed to validate culturally explicit data collection instruments d...

  10. Heuristic method for searches on large data-sets organised using network models

    NASA Astrophysics Data System (ADS)

    Ruiz-Fernández, D.; Quintana-Pacheco, Y.

    2016-05-01

    Searches on large data-sets have become an important issue in recent years. An alternative, which has achieved good results, is the use of methods relying on data mining techniques, such as cluster-based retrieval. This paper proposes a heuristic search that is based on an organisational model that reflects similarity relationships among data elements. The search is guided by using quality estimators of model nodes, which are obtained by the progressive evaluation of the given target function for the elements associated with each node. The results of the experiments confirm the effectiveness of the proposed algorithm. High-quality solutions are obtained evaluating a relatively small percentage of elements in the data-sets.

  11. A semi-implicit level set method for multiphase flows and fluid-structure interaction problems

    NASA Astrophysics Data System (ADS)

    Cottet, Georges-Henri; Maitre, Emmanuel

    2016-06-01

    In this paper we present a novel semi-implicit time-discretization of the level set method introduced in [8] for fluid-structure interaction problems. The idea stems from a linear stability analysis derived on a simplified one-dimensional problem. The semi-implicit scheme relies on a simple filter operating as a pre-processing on the level set function. It applies to multiphase flows driven by surface tension as well as to fluid-structure interaction problems. The semi-implicit scheme avoids the stability constraints that explicit scheme need to satisfy and reduces significantly the computational cost. It is validated through comparisons with the original explicit scheme and refinement studies on two-dimensional benchmarks.

  12. A new method of excitation control based on fuzzy set theory

    SciTech Connect

    Handschin, E.; Hoffmann, W.; Reyer, F.; Stephanblome, T.; Schluecking, U.; Westermann, D. ); Ahmed, S.S. )

    1994-02-01

    The synthesis of the structure of the PSS and its parameterization are based entirely on method of linear system theory. Thus the desorbed effect of the PSS is limited to a bounded area around one system operating point. The use of a controller based on fuzzy set theory introduces an event controlled excitation of the synchronous machine taking into account the power system operation. The desired response of the fuzzy controller is given by a set of rules which are obtained from the limits of the voltage regulator and the undesired performance of the conventional excitation control. A fuzzy controller has been developed for which simulation results are provided. These results support the concept of a fuzzy controller for the purpose of excitation control. They show that a well designed fuzzy controller is superior to a fast excitation control with an additional PSS.

  13. Unsaturated fractured rock characterization methods and data sets at the Apache Leap Tuff Site

    SciTech Connect

    Rasmussen, T.C.; Evans, D.D.; Sheets, P.J.; Blanford, J.H.

    1990-08-01

    Performance assessment of high-level nuclear waste containment feasibility requires representative values of parameters as input, including parameter moments, distributional characteristics, and covariance structures between parameters. To meet this need, characterization methods and data sets for interstitial, hydraulic, pneumatic and thermal parameters for a slightly welded fractured tuff at the Apache Leap Tuff Site situated in central Arizona are reported in this document. The data sets include the influence of matric suction on measured parameters. Spatial variability is investigated by sampling along nine boreholes at regular distances. Laboratory parameter estimates for 105 core segments are provided, as well as field estimates centered on the intervals where the core segments were collected. Measurement uncertainty is estimated by repetitively testing control samples. 31 refs., 10 figs., 21 tabs.

  14. Wave breaking over sloping beaches using a coupled boundary integral-level set method

    SciTech Connect

    Garzon, M.; Adalsteinsson, D.; Gray, L.; Sethian, J.A.

    2003-12-08

    We present a numerical method for tracking breaking waves over sloping beaches. We use a fully non-linear potential model for in-compressible, irrotational and inviscid flow, and consider the effects of beach topography on breaking waves. The algorithm uses a Boundary Element Method (BEM) to compute the velocity at the interface, coupled to a Narrow Band Level Set Method to track the evolving air/water interface, and an associated extension equation to update the velocity potential both on and off the interface. The formulation of the algorithm is applicable to two and three dimensional breaking waves; in this paper, we concentrate on two-dimensional results showing wave breaking and rollup, and perform numerical convergence studies and comparison with previous techniques.

  15. Simultaneous segmentation and reconstruction: A level set method approach for limited view computed tomography

    SciTech Connect

    Yoon, Sungwon; Pineda, Angel R.; Fahrig, Rebecca

    2010-05-15

    Purpose: An iterative tomographic reconstruction algorithm that simultaneously segments and reconstructs the reconstruction domain is proposed and applied to tomographic reconstructions from a sparse number of projection images. Methods: The proposed algorithm uses a two-phase level set method segmentation in conjunction with an iterative tomographic reconstruction to achieve simultaneous segmentation and reconstruction. The simultaneous segmentation and reconstruction is achieved by alternating between level set function evolutions and per-region intensity value updates. To deal with the limited number of projections, a priori information about the reconstruction is enforced via penalized likelihood function. Specifically, smooth function within each region (piecewise smooth function) and bounded function intensity values for each region are assumed. Such a priori information is formulated into a quadratic objective function with linear bound constraints. The level set function evolutions are achieved by artificially time evolving the level set function in the negative gradient direction; the intensity value updates are achieved by using the gradient projection conjugate gradient algorithm. Results: The proposed simultaneous segmentation and reconstruction results were compared to ''conventional'' iterative reconstruction (with no segmentation), iterative reconstruction followed by segmentation, and filtered backprojection. Improvements of 6%-13% in the normalized root mean square error were observed when the proposed algorithm was applied to simulated projections of a numerical phantom and to real fan-beam projections of the Catphan phantom, both of which did not satisfy the a priori assumptions. Conclusions: The proposed simultaneous segmentation and reconstruction resulted in improved reconstruction image quality. The algorithm correctly segments the reconstruction space into regions, preserves sharp edges between different regions, and smoothes the noise

  16. A self-adaptive oriented particles Level-Set method for tracking interfaces

    NASA Astrophysics Data System (ADS)

    Ianniello, S.; Di Mascio, A.

    2010-02-01

    A new method for tracking evolving interfaces by lagrangian particles in conjunction with a Level-Set approach is introduced. This numerical technique is based on the use of time evolution equations for fundamental vector and tensor quantities defined on the front and represents a new and convenient way to couple the advantages of the Eulerian description given by a Level-Set function ϕ to the use of Lagrangian massless particles. The term oriented points out that the information advected by the particles not only concern the spatial location, but also the local (outward) normal vector n to the interface Γ and the second fundamental tensor (the shape operator) ∇n. The particles are exactly located upon Γ and provide all the requested information for tracking the interface on their own. In addition, a self-adaptive mechanism suitably modifies, at each time step, the markers distribution in the numerical domain: each particle behaves both as a potential seeder of new markers on Γ (so as to guarantee an accurate reconstruction of the interface) and a de-seeder (to avoid any useless gathering of markers and to limit the computational effort). The algorithm is conceived to avoid any transport equation for ϕ and to confine the Level-Set function to the role of a mere post-processing tool; thus, all the numerical diffusion problems usually affecting the Level-Set methodology are removed. The method has been tested both on 2D and 3D configurations; it carries out a fast reconstruction of the interface and its accuracy is only limited by the spatial resolution of the mesh.

  17. A method of setting limits for the purpose of quality assurance.

    PubMed

    Sanghangthum, Taweap; Suriyapee, Sivalee; Kim, Gwe-Ya; Pawlicki, Todd

    2013-10-01

    The result from any assurance measurement needs to be checked against some limits for acceptability. There are two types of limits; those that define clinical acceptability (action limits) and those that are meant to serve as a warning that the measurement is close to the action limits (tolerance limits). Currently, there is no standard procedure to set these limits. In this work, we propose an operational procedure to set tolerance limits and action limits. The approach to establish the limits is based on techniques of quality engineering using control charts and a process capability index. The method is different for tolerance limits and action limits with action limits being categorized into those that are specified and unspecified. The procedure is to first ensure process control using the I-MR control charts. Then, the tolerance limits are set equal to the control chart limits on the I chart. Action limits are determined using the Cpm process capability index with the requirements that the process must be in-control. The limits from the proposed procedure are compared to an existing or conventional method. Four examples are investigated: two of volumetric modulated arc therapy (VMAT) point dose quality assurance (QA) and two of routine linear accelerator output QA. The tolerance limits range from about 6% larger to 9% smaller than conventional action limits for VMAT QA cases. For the linac output QA, tolerance limits are about 60% smaller than conventional action limits. The operational procedure describe in this work is based on established quality management tools and will provide a systematic guide to set up tolerance and action limits for different equipment and processes. PMID:24043363

  18. A method of setting limits for the purpose of quality assurance

    NASA Astrophysics Data System (ADS)

    Sanghangthum, Taweap; Suriyapee, Sivalee; Kim, Gwe-Ya; Pawlicki, Todd

    2013-10-01

    The result from any assurance measurement needs to be checked against some limits for acceptability. There are two types of limits; those that define clinical acceptability (action limits) and those that are meant to serve as a warning that the measurement is close to the action limits (tolerance limits). Currently, there is no standard procedure to set these limits. In this work, we propose an operational procedure to set tolerance limits and action limits. The approach to establish the limits is based on techniques of quality engineering using control charts and a process capability index. The method is different for tolerance limits and action limits with action limits being categorized into those that are specified and unspecified. The procedure is to first ensure process control using the I-MR control charts. Then, the tolerance limits are set equal to the control chart limits on the I chart. Action limits are determined using the Cpm process capability index with the requirements that the process must be in-control. The limits from the proposed procedure are compared to an existing or conventional method. Four examples are investigated: two of volumetric modulated arc therapy (VMAT) point dose quality assurance (QA) and two of routine linear accelerator output QA. The tolerance limits range from about 6% larger to 9% smaller than conventional action limits for VMAT QA cases. For the linac output QA, tolerance limits are about 60% smaller than conventional action limits. The operational procedure describe in this work is based on established quality management tools and will provide a systematic guide to set up tolerance and action limits for different equipment and processes.

  19. Methods for Adjusting U.S. Geological Survey Rural Regression Peak Discharges in an Urban Setting

    USGS Publications Warehouse

    Moglen, Glenn E.; Shivers, Dorianne E.

    2006-01-01

    A study was conducted of 78 U.S. Geological Survey gaged streams that have been subjected to varying degrees of urbanization over the last three decades. Flood-frequency analysis coupled with nonlinear regression techniques were used to generate a set of equations for converting peak discharge estimates determined from rural regression equations to a set of peak discharge estimates that represent known urbanization. Specifically, urban regression equations for the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year return periods were calibrated as a function of the corresponding rural peak discharge and the percentage of impervious area in a watershed. The results of this study indicate that two sets of equations, one set based on imperviousness and one set based on population density, performed well. Both sets of equations are dependent on rural peak discharges, a measure of development (average percentage of imperviousness or average population density), and a measure of homogeneity of development within a watershed. Average imperviousness was readily determined by using geographic information system methods and commonly available land-cover data. Similarly, average population density was easily determined from census data. Thus, a key advantage to the equations developed in this study is that they do not require field measurements of watershed characteristics as did the U.S. Geological Survey urban equations developed in an earlier investigation. During this study, the U.S. Geological Survey PeakFQ program was used as an integral tool in the calibration of all equations. The scarcity of historical land-use data, however, made exclusive use of flow records necessary for the 30-year period from 1970 to 2000. Such relatively short-duration streamflow time series required a nonstandard treatment of the historical data function of the PeakFQ program in comparison to published guidelines. Thus, the approach used during this investigation does not fully comply with the

  20. Methods for Identifying Neisseria meningitidis Carriers: A Multi-Center Study in the African Meningitis Belt

    PubMed Central

    Basta, Nicole E.; Stuart, James M.; Nascimento, Maria C.; Manigart, Olivier; Trotter, Caroline; Hassan-King, Musa; Chandramohan, Daniel; Sow, Samba O.; Berthe, Abdoulaye; Bedru, Ahmed; Tekletsion, Yenenesh K.; Collard, Jean-Marc; Jusot, Jean-François; Diallo, Aldiouma; Basséne, Hubert; Daugla, Doumagoum M.; Gamougam, Khadidja; Hodgson, Abraham; Forgor, Abudulai A.; Omotara, Babatunji A.; Gadzama, Galadima B.; Watkins, Eleanor R.; Rebbetts, Lisa S.; Diallo, Kanny; Weiss, Noel S.; Halloran, M. Elizabeth; Maiden, Martin C. J.; Greenwood, Brian

    2013-01-01

    Objective Detection of meningococcal carriers is key to understanding the epidemiology of Neisseria meningitidis, yet no gold standard has been established. Here, we directly compare two methods for collecting pharyngeal swabs to identify meningococcal carriers. Methods We conducted cross-sectional surveys of schoolchildren at multiple sites in Africa to compare swabbing the posterior pharynx behind the uvula (U) to swabbing the posterior pharynx behind the uvula plus one tonsil (T). Swabs were cultured immediately and analyzed using molecular methods. Results One thousand and six paired swab samples collected from schoolchildren in four countries were analyzed. Prevalence of meningococcal carriage was 6.9% (95% CI: 5.4-8.6%) based on the results from both swabs, but the observed prevalence was lower based on one swab type alone. Prevalence based on the T swab or the U swab alone was similar (5.2% (95% CI: 3.8-6.7%) versus 4.9% (95% CI: 3.6-6.4%) respectively (p=0.6)). The concordance between the two methods was 96.3% and the kappa was 0.61 (95% CI: 0.50-0.73), indicating good agreement. Conclusions These two commonly used methods for collecting pharyngeal swabs provide consistent estimates of the prevalence of carriage, but both methods misclassified carriers to some degree, leading to underestimates of the prevalence. PMID:24194921

  1. Use of handheld X-ray fluorescence as a non-invasive method to distinguish between Asian and African elephant tusks

    PubMed Central

    Buddhachat, Kittisak; Thitaram, Chatchote; Brown, Janine L.; Klinhom, Sarisa; Bansiddhi, Pakkanut; Penchart, Kitichaya; Ouitavon, Kanita; Sriaksorn, Khanittha; Pa-in, Chalermpol; Kanchanasaka, Budsabong; Somgird, Chaleamchat; Nganvongpanit, Korakot

    2016-01-01

    We describe the use of handheld X-ray fluorescence, for elephant tusk species identification. Asian (n = 72) and African (n = 85) elephant tusks were scanned and we utilized the species differences in elemental composition to develop a functional model differentiating between species with high precision. Spatially, the majority of measured elements (n = 26) exhibited a homogeneous distribution in cross-section, but a more heterologous pattern in the longitudinal direction. Twenty-one of twenty four elements differed between Asian and African samples. Data were subjected to hierarchical cluster analysis followed by a stepwise discriminant analysis, which identified elements for the functional equation. The best equation consisted of ratios of Si, S, Cl, Ti, Mn, Ag, Sb and W, with Zr as the denominator. Next, Bayesian binary regression model analysis was conducted to predict the probability that a tusk would be of African origin. A cut-off value was established to improve discrimination. This Bayesian hybrid classification model was then validated by scanning an additional 30 Asian and 41 African tusks, which showed high accuracy (94%) and precision (95%) rates. We conclude that handheld XRF is an accurate, non-invasive method to discriminate origin of elephant tusks provides rapid results applicable to use in the field. PMID:27097717

  2. Use of handheld X-ray fluorescence as a non-invasive method to distinguish between Asian and African elephant tusks.

    PubMed

    Buddhachat, Kittisak; Thitaram, Chatchote; Brown, Janine L; Klinhom, Sarisa; Bansiddhi, Pakkanut; Penchart, Kitichaya; Ouitavon, Kanita; Sriaksorn, Khanittha; Pa-in, Chalermpol; Kanchanasaka, Budsabong; Somgird, Chaleamchat; Nganvongpanit, Korakot

    2016-01-01

    We describe the use of handheld X-ray fluorescence, for elephant tusk species identification. Asian (n = 72) and African (n = 85) elephant tusks were scanned and we utilized the species differences in elemental composition to develop a functional model differentiating between species with high precision. Spatially, the majority of measured elements (n = 26) exhibited a homogeneous distribution in cross-section, but a more heterologous pattern in the longitudinal direction. Twenty-one of twenty four elements differed between Asian and African samples. Data were subjected to hierarchical cluster analysis followed by a stepwise discriminant analysis, which identified elements for the functional equation. The best equation consisted of ratios of Si, S, Cl, Ti, Mn, Ag, Sb and W, with Zr as the denominator. Next, Bayesian binary regression model analysis was conducted to predict the probability that a tusk would be of African origin. A cut-off value was established to improve discrimination. This Bayesian hybrid classification model was then validated by scanning an additional 30 Asian and 41 African tusks, which showed high accuracy (94%) and precision (95%) rates. We conclude that handheld XRF is an accurate, non-invasive method to discriminate origin of elephant tusks provides rapid results applicable to use in the field. PMID:27097717

  3. African bees to control African elephants

    NASA Astrophysics Data System (ADS)

    Vollrath, Fritz; Douglas-Hamilton, Iain

    2002-11-01

    Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

  4. Some free boundary problems in potential flow regime usinga based level set method

    SciTech Connect

    Garzon, M.; Bobillo-Ares, N.; Sethian, J.A.

    2008-12-09

    Recent advances in the field of fluid mechanics with moving fronts are linked to the use of Level Set Methods, a versatile mathematical technique to follow free boundaries which undergo topological changes. A challenging class of problems in this context are those related to the solution of a partial differential equation posed on a moving domain, in which the boundary condition for the PDE solver has to be obtained from a partial differential equation defined on the front. This is the case of potential flow models with moving boundaries. Moreover the fluid front will possibly be carrying some material substance which will diffuse in the front and be advected by the front velocity, as for example the use of surfactants to lower surface tension. We present a Level Set based methodology to embed this partial differential equations defined on the front in a complete Eulerian framework, fully avoiding the tracking of fluid particles and its known limitations. To show the advantages of this approach in the field of Fluid Mechanics we present in this work one particular application: the numerical approximation of a potential flow model to simulate the evolution and breaking of a solitary wave propagating over a slopping bottom and compare the level set based algorithm with previous front tracking models.

  5. Numerical Simulation of Dynamic Contact Angles and Contact Lines in Multiphase Flows using Level Set Method

    NASA Astrophysics Data System (ADS)

    Pendota, Premchand

    Many physical phenomena and industrial applications involve multiphase fluid flows and hence it is of high importance to be able to simulate various aspects of these flows accurately. The Dynamic Contact Angles (DCA) and the contact lines at the wall boundaries are a couple of such important aspects. In the past few decades, many mathematical models were developed for predicting the contact angles of the inter-face with the wall boundary under various flow conditions. These models are used to incorporate the physics of DCA and contact line motion in numerical simulations using various interface capturing/tracking techniques. In the current thesis, a simple approach to incorporate the static and dynamic contact angle boundary conditions using the level set method is developed and implemented in multiphase CFD codes, LIT (Level set Interface Tracking) (Herrmann (2008)) and NGA (flow solver) (Desjardins et al (2008)). Various DCA models and associated boundary conditions are reviewed. In addition, numerical aspects such as the occurrence of a stress singularity at the contact lines and grid convergence of macroscopic interface shape are dealt with in the context of the level set approach.

  6. Implementation of a near-optimal global set point control method in a DDC controller

    SciTech Connect

    Cascia, M.A.

    2000-07-01

    A near-optimal global set point control method that can be implemented in an energy management system's (EMS) DDC controller is described in this paper. Mathematical models are presented for the power consumption of electric chillers, hot water boilers, chilled and hot water pumps, and air handler fans, which allow the calculation of near-optimal chilled water, hot water, and coil discharge air set points to minimize power consumption, based on data collected by the EMS. Also optimized are the differential and static pressure set points for the variable speed pumps and fans. A pilot test of this control methodology was implemented for a cooling plant at a pharmaceutical manufacturing facility near Dallas, Texas. Data collected at this site showed good agreement between the actual power consumed by the chillers, chilled water pumps, and air handlers and that predicted by the models. An approximate model was developed to calculate real-time power savings in the DDC controller. A third-party energy accounting program was used to track savings due to the near-optimal control, and results show a monthly KWH reduction ranging from 3% to 14%.

  7. Evaluation of Methods for Measuring Soil Organic Carbon in West African Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased interest in implementing projects in the Sahel region of Africa for sequestration of atmospheric carbon dioxide in soil organic matter has intensified the need for methods that accurately measure soil C but are also suitable for use by often resource limited soil analysis laboratories in t...

  8. Healthier home food preparation methods and youth and caregiver psychosocial factors are associated with lower BMI in African American youth.

    PubMed

    Kramer, Rebecca F; Coutinho, Anastasia J; Vaeth, Elisabeth; Christiansen, Karina; Suratkar, Sonali; Gittelsohn, Joel

    2012-05-01

    Obesity disproportionately affects African American (AA) children and adolescents and leads to an increased risk of adult chronic diseases. Eating few meals at home has been implicated as a cause of obesity among youth, but to our knowledge, previous studies have not specifically investigated this relationship in AA adolescents or looked at both the healthfulness and frequency of home meals in AA households. The objective of the present study was to investigate the relationship between home food preparation and adolescent BMI in a sample of 240 AA adolescents aged 10-15 y and their caregivers. Multiple linear regressions were used to model psychosocial characteristics, household factors, and adolescent and caregiver food preparation behaviors as predictors of adolescent BMI, and psychosocial and household factors as predictors of food preparation behavior. Adolescents in the sample had a mean BMI-for-age percentile of 70.4, and >90% of the sample families received at least one form of food assistance. Adolescent children of caregivers who used healthier cooking methods were more likely to use healthy cooking methods themselves (P = 0.02). Having more meals prepared by a caregiver was predictive of higher BMI-for-age percentile in adolescents (P = 0.02), but healthier cooking methods used by the caregiver was associated with reduced risk of adolescent overweight or obesity (P < 0.01). Meals prepared at home in AA households do not necessarily promote healthy BMI in youth. Family meals are a promising adolescent obesity prevention strategy, but it is important to target both frequency and healthfulness of meals prepared at home for effective health promotion in AA families. PMID:22457390

  9. Preliminary studies developing methods for the control of Chrysomya putoria, the African latrine fly, in pit latrines in The Gambia

    PubMed Central

    Lindsay, T C; Jawara, M; D'Alessandro, U; Pinder, M; Lindsay, S W

    2013-01-01

    Objective To explore ways of controlling Chrysomya putoria, the African latrine fly, in pit latrines. As pit latrines are a major source of these flies, eliminating these important breeding sites is likely to reduce village fly populations, and may reduce the spread of diarrhoeal pathogens. Methods We treated 24 latrines in a Gambian village: six each with (i) pyriproxyfen, an insect juvenile hormone mimic formulated as Sumilarv® 0.5G, a 0.5% pyriproxyfen granule, (ii) expanded polystyrene beads (EPB), (iii) local soap or (iv) no treatment as controls. Flies were collected using exit traps placed over the drop holes, weekly for five weeks. In a separate study, we tested whether latrines also function as efficient flytraps using the faecal odours as attractants. We constructed six pit latrines each with a built-in flytrap and tested their catching efficiency compared to six fish-baited box traps positioned 10 m from the latrine. Focus group discussions conducted afterwards assessed the acceptability of the flytrap latrines. Results Numbers of emerging C. putoria were reduced by 96.0% (95% CIs: 94.5–97.2%) 4–5 weeks after treatment with pyriproxyfen; by 64.2% (95% CIs: 51.8–73.5%) after treatment with local soap; by 41.3% (95% CIs = 24.0–54.7%) after treatment with EPB 3–5 weeks after treatment. Flytraps placed on latrines collected C. putoria and were deemed acceptable to local communities. Conclusions Sumilarv 0.5G shows promise as a chemical control agent, whilst odour-baited latrine traps may prove a useful method of non-chemical fly control. Both methods warrant further development to reduce fly production from pit latrines. A combination of interventions may prove effective for the control of latrine flies and the diseases they transmit. PMID:23198767

  10. Vessel Segmentation and Blood Flow Simulation Using Level-Sets and Embedded Boundary Methods

    SciTech Connect

    Deschamps, T; Schwartz, P; Trebotich, D; Colella, P; Saloner, D; Malladi, R

    2004-12-09

    In this article we address the problem of blood flow simulation in realistic vascular objects. The anatomical surfaces are extracted by means of Level-Sets methods that accurately model the complex and varying surfaces of pathological objects such as aneurysms and stenoses. The surfaces obtained are defined at the sub-pixel level where they intersect the Cartesian grid of the image domain. It is therefore straightforward to construct embedded boundary representations of these objects on the same grid, for which recent work has enabled discretization of the Navier-Stokes equations for incompressible fluids. While most classical techniques require construction of a structured mesh that approximates the surface in order to extrapolate a 3D finite-element gridding of the whole volume, our method directly simulates the blood-flow inside the extracted surface without losing any complicated details and without building additional grids.

  11. A GPU-accelerated adaptive discontinuous Galerkin method for level set equation

    NASA Astrophysics Data System (ADS)

    Karakus, A.; Warburton, T.; Aksel, M. H.; Sert, C.

    2016-01-01

    This paper presents a GPU-accelerated nodal discontinuous Galerkin method for the solution of two- and three-dimensional level set (LS) equation on unstructured adaptive meshes. Using adaptive mesh refinement, computations are localised mostly near the interface location to reduce the computational cost. Small global time step size resulting from the local adaptivity is avoided by local time-stepping based on a multi-rate Adams-Bashforth scheme. Platform independence of the solver is achieved with an extensible multi-threading programming API that allows runtime selection of different computing devices (GPU and CPU) and different threading interfaces (CUDA, OpenCL and OpenMP). Overall, a highly scalable, accurate and mass conservative numerical scheme that preserves the simplicity of LS formulation is obtained. Efficiency, performance and local high-order accuracy of the method are demonstrated through distinct numerical test cases.

  12. Test case set generation method on MC/DC based on binary tree

    NASA Astrophysics Data System (ADS)

    Wang, Jun-jie; Zhang, Bo; Chen, Yuan

    2013-03-01

    Exploring efficient, reliable test case design methods has been tester pursuit of the goal. Along with the aerospace software logic complexity of improving and software scale enlarging, this requirement also gets more compelling. Test case design techniques suited for MC/DC improved test case design efficiency, increase the test coverage. It is suitable to test the software that logical relationship is complicated comparatively. Some software test tools provide the function to calculate the test coverage. And it can assess the test cases whether on the MC/DC or not. But the software tester needs the reverse thinking. The paper puts forward that design the test case by Unique-cause and Masking approach. And it proposes automatic generation method of test case on MC/DC. It improved the efficiency and correctness of generation the test case set on DC/DC.

  13. Validation of non-rigid point-set registration methods using a porcine bladder pelvic phantom

    NASA Astrophysics Data System (ADS)

    Zakariaee, Roja; Hamarneh, Ghassan; Brown, Colin J.; Spadinger, Ingrid

    2016-01-01

    The problem of accurate dose accumulation in fractionated radiotherapy treatment for highly deformable organs, such as bladder, has garnered increasing interest over the past few years. However, more research is required in order to find a robust and efficient solution and to increase the accuracy over the current methods. The purpose of this study was to evaluate the feasibility and accuracy of utilizing non-rigid (affine or deformable) point-set registration in accumulating dose in bladder of different sizes and shapes. A pelvic phantom was built to house an ex vivo porcine bladder with fiducial landmarks adhered onto its surface. Four different volume fillings of the bladder were used (90, 180, 360 and 480 cc). The performance of MATLAB implementations of five different methods were compared, in aligning the bladder contour point-sets. The approaches evaluated were coherent point drift (CPD), gaussian mixture model, shape context, thin-plate spline robust point matching (TPS-RPM) and finite iterative closest point (ICP-finite). The evaluation metrics included registration runtime, target registration error (TRE), root-mean-square error (RMS) and Hausdorff distance (HD). The reference (source) dataset was alternated through all four points-sets, in order to study the effect of reference volume on the registration outcomes. While all deformable algorithms provided reasonable registration results, CPD provided the best TRE values (6.4 mm), and TPS-RPM yielded the best mean RMS and HD values (1.4 and 6.8 mm, respectively). ICP-finite was the fastest technique and TPS-RPM, the slowest.

  14. Validation of non-rigid point-set registration methods using a porcine bladder pelvic phantom.

    PubMed

    Zakariaee, Roja; Hamarneh, Ghassan; Brown, Colin J; Spadinger, Ingrid

    2016-01-21

    The problem of accurate dose accumulation in fractionated radiotherapy treatment for highly deformable organs, such as bladder, has garnered increasing interest over the past few years. However, more research is required in order to find a robust and efficient solution and to increase the accuracy over the current methods. The purpose of this study was to evaluate the feasibility and accuracy of utilizing non-rigid (affine or deformable) point-set registration in accumulating dose in bladder of different sizes and shapes. A pelvic phantom was built to house an ex vivo porcine bladder with fiducial landmarks adhered onto its surface. Four different volume fillings of the bladder were used (90, 180, 360 and 480 cc). The performance of MATLAB implementations of five different methods were compared, in aligning the bladder contour point-sets. The approaches evaluated were coherent point drift (CPD), gaussian mixture model, shape context, thin-plate spline robust point matching (TPS-RPM) and finite iterative closest point (ICP-finite). The evaluation metrics included registration runtime, target registration error (TRE), root-mean-square error (RMS) and Hausdorff distance (HD). The reference (source) dataset was alternated through all four points-sets, in order to study the effect of reference volume on the registration outcomes. While all deformable algorithms provided reasonable registration results, CPD provided the best TRE values (6.4 mm), and TPS-RPM yielded the best mean RMS and HD values (1.4 and 6.8 mm, respectively). ICP-finite was the fastest technique and TPS-RPM, the slowest. PMID:26740511

  15. Simulation method for transmission-type radio-frequency single-electron transistor (RF-SET) operation by SPICE

    NASA Astrophysics Data System (ADS)

    Yu, Yun Seop; Oh, Jung Hyun; Kim, Hee Tae; Kim, Yong Gyu; Son, Seung Hun; Choi, Bum Ho; Hwang, Sung Woo; Ahn, Doyel

    2009-02-01

    An efficient simulation method for transmission-type radio-frequency single-electron transistors (RF-SETs) is developed. By introducing equivalent circuits of propagating microwaves through RF cables, we solve the master equation for RF-SETs self-consistently by using the conventional circuit simulator SPICE together with the SET current model. By examining transmitted waves from the transmission-type RF-SET, we show that the developed method successfully reproduces the numerical reference methods (calculated self- consistently). We also show that our method provides simple and fast ways to simulate and analyze RF-SETs even under complicated circuit geometry and in high frequencies over GHz. Based on the developed simulation method, we introduce the modulation technique to estimate the charge sensitivity of the transmission-type RF-SET.

  16. IIA: a novel method to optimize media instruction set of embedded processor

    NASA Astrophysics Data System (ADS)

    Chen, Keming; Yu, Guojun; Liu, Peng; Yao, Qingdong

    2006-02-01

    To accelerate media processing, many media enhancement instructions have been adopted into the instruction set of embedded processors. In this paper, a novel method, called interaction between instructions and algorithms (IIA), is proposed to optimize these media enhancement instructions. Based on the analysis for inherent characteristics of video processing algorithms and processor's architecture, three measures are proposed: three single-cycle instructions for manipulation on bit level are implemented to speed up variable-length decoding; a data path is designed to solve data misalignment in SIMD processing instead of software programs; a memory architecture is proposed to support 128-bit word parallel processing. All these suggestions are used in the optimization of an embedded processor, MediaDSP3200 which fuses RISC architecture and DSP computation capability thoroughly and achieves reduced instruction and 64-bit SIMD instruction set with various addressing mode in a unified RISC pipeline stage architecture. Simulation results show that this optimization method can reduce more than 26.4% of clock cycles for VLD, 47.8% for IDCT and 66.8% for MC in real-time processing.

  17. An improved method to set significance thresholds for β diversity testing in microbial community comparisons.

    PubMed

    Gülay, Arda; Smets, Barth F

    2015-09-01

    Exploring the variation in microbial community diversity between locations (β diversity) is a central topic in microbial ecology. Currently, there is no consensus on how to set the significance threshold for β diversity. Here, we describe and quantify the technical components of β diversity, including those associated with the process of subsampling. These components exist for any proposed β diversity measurement procedure. Further, we introduce a strategy to set significance thresholds for β diversity of any group of microbial samples using rarefaction, invoking the notion of a meta-community. The proposed technique was applied to several in silico generated operational taxonomic unit (OTU) libraries and experimental 16S rRNA pyrosequencing libraries. The latter represented microbial communities from different biological rapid sand filters at a full-scale waterworks. We observe that β diversity, after subsampling, is inflated by intra-sample differences; this inflation is avoided in the proposed method. In addition, microbial community evenness (Gini > 0.08) strongly affects all β diversity estimations due to bias associated with rarefaction. Where published methods to test β significance often fail, the proposed meta-community-based estimator is more successful at rejecting insignificant β diversity values. Applying our approach, we reveal the heterogeneous microbial structure of biological rapid sand filters both within and across filters. PMID:25534614

  18. A level set method for determining critical curvatures for drainage and imbibition.

    PubMed

    Prodanović, Masa; Bryant, Steven L

    2006-12-15

    An accurate description of the mechanics of pore level displacement of immiscible fluids could significantly improve the predictions from pore network models of capillary pressure-saturation curves, interfacial areas and relative permeability in real porous media. If we assume quasi-static displacement, at constant pressure and surface tension, pore scale interfaces are modeled as constant mean curvature surfaces, which are not easy to calculate. Moreover, the extremely irregular geometry of natural porous media makes it difficult to evaluate surface curvature values and corresponding geometric configurations of two fluids. Finally, accounting for the topological changes of the interface, such as splitting or merging, is nontrivial. We apply the level set method for tracking and propagating interfaces in order to robustly handle topological changes and to obtain geometrically correct interfaces. We describe a simple but robust model for determining critical curvatures for throat drainage and pore imbibition. The model is set up for quasi-static displacements but it nevertheless captures both reversible and irreversible behavior (Haines jump, pore body imbibition). The pore scale grain boundary conditions are extracted from model porous media and from imaged geometries in real rocks. The method gives quantitative agreement with measurements and with other theories and computational approaches. PMID:17027812

  19. GPU-Based Visualization of 3D Fluid Interfaces using Level Set Methods

    NASA Astrophysics Data System (ADS)

    Kadlec, B. J.

    2009-12-01

    We model a simple 3D fluid-interface problem using the level set method and visualize the interface as a dynamic surface. Level set methods allow implicit handling of complex topologies deformed by evolutions where sharp changes and cusps are present without destroying the representation. We present a highly optimized visualization and computation algorithm that is implemented in CUDA to run on the NVIDIA GeForce 295 GTX. CUDA is a general purpose parallel computing architecture that allows the NVIDIA GPU to be treated like a data parallel supercomputer in order to solve many computational problems in a fraction of the time required on a CPU. CUDA is compared to the new OpenCL™ (Open Computing Language), which is designed to run on heterogeneous computing environments but does not take advantage of low-level features in NVIDIA hardware that provide significant speedups. Therefore, our technique is implemented using CUDA and results are compared to a single CPU implementation to show the benefits of using the GPU and CUDA for visualizing fluid-interface problems. We solve a 1024^3 problem and experience significant speedup using the NVIDIA GeForce 295 GTX. Implementation details for mapping the problem to the GPU architecture are described as well as discussion on porting the technique to heterogeneous devices (AMD, Intel, IBM) using OpenCL. The results present a new interactive system for computing and visualizing the evolution of fluid interface problems on the GPU.

  20. A flexible method for estimating the fraction of fitness influencing mutations from large sequencing data sets.

    PubMed

    Moon, Sunjin; Akey, Joshua M

    2016-06-01

    A continuing challenge in the analysis of massively large sequencing data sets is quantifying and interpreting non-neutrally evolving mutations. Here, we describe a flexible and robust approach based on the site frequency spectrum to estimate the fraction of deleterious and adaptive variants from large-scale sequencing data sets. We applied our method to approximately 1 million single nucleotide variants (SNVs) identified in high-coverage exome sequences of 6515 individuals. We estimate that the fraction of deleterious nonsynonymous SNVs is higher than previously reported; quantify the effects of genomic context, codon bias, chromatin accessibility, and number of protein-protein interactions on deleterious protein-coding SNVs; and identify pathways and networks that have likely been influenced by positive selection. Furthermore, we show that the fraction of deleterious nonsynonymous SNVs is significantly higher for Mendelian versus complex disease loci and in exons harboring dominant versus recessive Mendelian mutations. In summary, as genome-scale sequencing data accumulate in progressively larger sample sizes, our method will enable increasingly high-resolution inferences into the characteristics and determinants of non-neutral variation. PMID:27197222

  1. Toward automatic computer aided dental X-ray analysis using level set method.

    PubMed

    Li, Shuo; Fevens, Thomas; Krzyzak, Adam; Jin, Chao; Li, Song

    2005-01-01

    A Computer Aided Dental X-rays Analysis (CADXA) framework is proposed to semi-automatically detect areas of bone loss and root decay in digital dental X-rays. In this framework, first, a new proposed competitive coupled level set method is proposed to segment the image into three pathologically meaningful regions using two coupled level set functions. Tailored for the dental clinical environment, the segmentation stage uses a trained support vector machine (SVM) classifier to provide initial contours. Then, based on the segmentation results, an analysis scheme is applied. First, the scheme builds an uncertainty map from which those areas with bone loss will be automatically detected. Secondly, the scheme employs a method based on the SVM and the average intensity profile to isolate the teeth and detect root decay. Experimental results show that our proposed framework is able to automatically detect the areas of bone loss and, when given the orientation of the teeth, it is able to automatically detect the root decay with a seriousness level marked for diagnosis. PMID:16685904

  2. A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana)

    PubMed Central

    Stansfield, Fiona J.

    2015-01-01

    The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323) were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to molar progression. These ‘Age Reference Lines’ were then associated with an age scale based on previous studies and Zimbabwean mandibles of known age. The new ranking produced a single age scale that proved useful for both male and female mandibles up to the maximum lifespan age of 70–75 years. Methods to aid in molar identification and the sexing of found jaws were also identified. PMID:25970428

  3. A Novel Objective Method of Estimating the Age of Mandibles from African Elephants (Loxodonta africana Africana).

    PubMed

    Stansfield, Fiona J

    2015-01-01

    The importance of assigning an accurate estimate of age and sex to elephant carcasses found in the wild has increased in recent years with the escalation in levels of poaching throughout Africa. Irregularities identified in current ageing techniques prompted the development of a new method to describe molar progression throughout life. Elephant mandibles (n = 323) were studied and a point near the distal dental alveolus was identified as being most useful in ranking each jaw according to molar progression. These 'Age Reference Lines' were then associated with an age scale based on previous studies and Zimbabwean mandibles of known age. The new ranking produced a single age scale that proved useful for both male and female mandibles up to the maximum lifespan age of 70-75 years. Methods to aid in molar identification and the sexing of found jaws were also identified. PMID:25970428

  4. [Control of human African trypanosomiasis in Luba in equatorial Guinea:evaluation of three methods].

    PubMed

    Simarro, P P; Sima, F O; Mir, M; Mateo, M J; Roche, J

    1991-01-01

    The object of this study was to (a) reduce the prevalence of sleeping sickness by serological testing, parasitological examination, and treatment of every infected person; (b) determine the maximum acceptable interval between serological surveys; and (c) define the impact of vector control, using monopyramidal non-impregnated traps, on the transmission. For this sero-parasitological survey, the focus in Luba was divided into three zones as follows: Epicentre A (with high prevalence, 27.5%), Epicentre B (with average prevalence, 8.3%), and Peripheral C (with moderate prevalence, 3.0%). Differences in the prevalence rates in the Epicentres and Peripheral zone permitted the use of three different approaches for control and epidemiological follow-up of the disease: (1) Serological examination of the entire population was carried out by the indirect immunofluorescent antibody test (IFAT), with six-month intervals in Epicentres A and B and once a year in the Peripheral zone C. (2) DIAGNOSIS AND TREATMENT: all IFAT seropositives were examined in Luba hospital for parasites, and every parasitologically confirmed patient was treated according to the WHO protocol of 1983. Another serological test (CATT) was applied to cases in which trypanosomes were not present and if this was positive, the CSF was examined. Cases with parasites and abnormal CSF were treated with melarsoprol, and those with a normal CSF received pentamidine. CATT-negative and parasite-negative cases were considered to be false-positives by IFAT and free of the disease. (3) Vector control: 74 monopyramidal traps (18 traps per km2) were set up in Epicentre A. The flies captured were collected once a month and sent to the programme's laboratory where they were identified and counted.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1934239

  5. LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation

    PubMed Central

    Huang, Shiyong; Ren, Yi; Choo, Kim-Kwang Raymond

    2016-01-01

    Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack). PMID:27326763

  6. LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation.

    PubMed

    Ren, Wei; Huang, Shiyong; Ren, Yi; Choo, Kim-Kwang Raymond

    2016-01-01

    Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack). PMID:27326763

  7. A New Ghost Cell/Level Set Method for Moving Boundary Problems: Application to Tumor Growth

    PubMed Central

    Macklin, Paul

    2011-01-01

    In this paper, we present a ghost cell/level set method for the evolution of interfaces whose normal velocity depend upon the solutions of linear and nonlinear quasi-steady reaction-diffusion equations with curvature-dependent boundary conditions. Our technique includes a ghost cell method that accurately discretizes normal derivative jump boundary conditions without smearing jumps in the tangential derivative; a new iterative method for solving linear and nonlinear quasi-steady reaction-diffusion equations; an adaptive discretization to compute the curvature and normal vectors; and a new discrete approximation to the Heaviside function. We present numerical examples that demonstrate better than 1.5-order convergence for problems where traditional ghost cell methods either fail to converge or attain at best sub-linear accuracy. We apply our techniques to a model of tumor growth in complex, heterogeneous tissues that consists of a nonlinear nutrient equation and a pressure equation with geometry-dependent jump boundary conditions. We simulate the growth of glioblastoma (an aggressive brain tumor) into a large, 1 cm square of brain tissue that includes heterogeneous nutrient delivery and varied biomechanical characteristics (white matter, gray matter, cerebrospinal fluid, and bone), and we observe growth morphologies that are highly dependent upon the variations of the tissue characteristics—an effect observed in real tumor growth. PMID:21331304

  8. Fast Electron Correlation Methods for Molecular Clusters without Basis Set Superposition Errors

    SciTech Connect

    Kamiya, Muneaki; Hirata, So; Valiev, Marat

    2008-02-19

    Two critical extensions to our fast, accurate, and easy-to-implement binary or ternary interaction method for weakly-interacting molecular clusters [Hirata et al. Mol. Phys. 103, 2255 (2005)] have been proposed, implemented, and applied to water hexamers, hydrogen fluoride chains and rings, and neutral and zwitterionic glycine–water clusters with an excellent result for an initial performance assessment. Our original method included up to two- or three-body Coulomb, exchange, and correlation energies exactly and higher-order Coulomb energies in the dipole–dipole approximation. In this work, the dipole moments are replaced by atom-centered point charges determined so that they reproduce the electrostatic potentials of the cluster subunits as closely as possible and also self-consistently with one another in the cluster environment. They have been shown to lead to dramatic improvement in the description of short-range electrostatic potentials not only of large, charge-separated subunits like zwitterionic glycine but also of small subunits. Furthermore, basis set superposition errors (BSSE) known to plague direct evaluation of weak interactions have been eliminated by com-bining the Valiron–Mayer function counterpoise (VMFC) correction with our binary or ternary interaction method in an economical fashion (quadratic scaling n2 with respect to the number of subunits n when n is small and linear scaling when n is large). A new variant of VMFC has also been proposed in which three-body and all higher-order Coulomb effects on BSSE are estimated approximately. The BSSE-corrected ternary interaction method with atom-centered point charges reproduces the VMFC-corrected results of conventional electron correlation calculations within 0.1 kcal/mol. The proposed method is significantly more accurate and also efficient than conventional correlation methods uncorrected of BSSE.

  9. Methods of training set construction: Towards improving performance for automated mesozooplankton image classification systems

    NASA Astrophysics Data System (ADS)

    Chang, Chun-Yi; Ho, Pei-Chi; Sastri, Akash R.; Lee, Yu-Ching; Gong, Gwo-Ching; Hsieh, Chih-hao

    2012-03-01

    The correspondence between variation in the physico-chemical properties of the water column and the taxonomic composition of zooplankton communities represents an important indicator of long-term and broad-scale change in marine systems. Evaluating and relating compositional change to various forms of perturbation demand routine taxonomic identification methods that can be applied rapidly and accurately. Traditional identification by human experts is accurate but very time-consuming. The application of automated image classification systems for plankton communities has emerged as a potential resolution to this limitation. The objective of this study is to evaluate how specific aspects of training set construction for the ZooScan system influenced our ability to relate variation in zooplankton taxonomic composition to variation of hydrographic properties in the East China Sea. Specifically, we compared the relative utility of zooplankton classifiers trained with the following: (i) water mass-specific and global training sets; (ii) balanced versus imbalanced training sets. The classification performance (accuracy and precision) of water-mass specific classifiers tended to decline with environmental dissimilarity, suggesting water-mass specificity However, similar classification performance was also achieved by training our system with samples representing all hydrographic sub-regions (i.e. a global classifier). After examining category-specific accuracy, we found that equal performance arises because the accuracy was mainly determined by dominant taxa. This apparently high classification accuracy was at the expense of accurate classification of rare taxa. To explore the basis for such biased classification, we trained our global classifier with an equal amount of training data for each category (balanced training). We found that balanced training had higher accuracy at recognizing rare taxa but low accuracy at abundant taxa. The errors introduced in recognition still

  10. Treatability and characterization of Natural Organic Matter (NOM) in South African waters using newly developed methods

    NASA Astrophysics Data System (ADS)

    Nkambule, T. I.; Krause, R. W. M.; Haarhoff, J.; Mamba, B. B.

    Managing the removal of Natural Organic Matter (NOM) or problematic components from water has become increasingly important. NOM is a heterogeneous mixture of organic compounds of human origin and derived from plant and microbial residues. The inadequate removal of NOM has a bearing on the capacity of the other treatment processes to remove organic micro-pollutants or inorganic species that may be present in the water. In addition the action of certain disinfection processes has been shown to lead to the formation of harmful disinfection by-products (DBPs). Owing to the complexity, in composition and structure, of NOM, the techniques currently employed for its characterization have a number of limitations, both in terms of quantification and removal of the NOM within short periods of time. The dissolved organic carbon (DOC), biodegradable dissolved organic carbon (BDOC) and Fluorescence Emission Excitation Matrices (FEEM) were used to characterize NOM from various water samples collected around South Africa. Characterization results gave an indication of the character of NOM present in all the water samples. FEEM and UV-Vis results indicated that most of the water samples were aromatic in nature, since they had high hydrophobic and humic acid-like materials content. Generally, the characterization data indicated a varying composition of NOM amongst the various sampling points. The polarity rapid assessment method (PRAM) was then employed as a rapid NOM characterization tool. The characterization under PRAM is based on preferential adsorption of dissolved organic matter (DOM) fractions onto solid phase extraction (SPE) sorbents. The PRAM also allows the separation of DOM into fractions by polarity, hence reducing the molecular heterogeneity of NOM and thus aiding the removal of specific NOM fractions from water. The PRAM provided a quick characterization of the NOM character. However, DOC quantification by the PRAM analysis was hindered by excessive carbon leaching

  11. 42 CFR 447.205 - Public notice of changes in Statewide methods and standards for setting payment rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SERVICES Payment Methods: General Provisions § 447.205 Public notice of changes in Statewide methods and standards for setting payment rates. (a) When notice is required. Except as specified in paragraph (b) of... standards for setting payment rates. 447.205 Section 447.205 Public Health CENTERS FOR MEDICARE &...

  12. Elimination of the linearization error and improved basis-set convergence within the FLAPW method

    NASA Astrophysics Data System (ADS)

    Michalicek, Gregor; Betzinger, Markus; Friedrich, Christoph; Blügel, Stefan

    2013-12-01

    We analyze in detail the error that arises from the linearization in linearized augmented-plane-wave (LAPW) basis functions around predetermined energies El and show that it can lead to undesirable dependences of the calculated results on method-inherent parameters such as energy parameters El and muffin-tin sphere radii. To overcome these dependences, we evaluate approaches that eliminate the linearization error systematically by adding local orbitals (LOs) to the basis set. We consider two kinds of LOs: (i) constructed from solutions ul(r,E) to the scalar-relativistic approximation of the radial Dirac equation with E>El and (ii) constructed from second energy derivatives ∂2ul(r,E)/∂E2 at E=El. We find that the latter eliminates the error most efficiently and yields the density functional answer to many electronic and materials properties with very high precision. Finally, we demonstrate that the so constructed LAPW +LO basis shows a more favorable convergence behavior than the conventional LAPW basis due to a better decoupling of muffin-tin and interstitial regions, similarly to the related APW +lo approach, which, however, requires an extra set of LOs to reach the same total energy.

  13. Time Domain Propagation of Quantum and Classical Systems using a Wavelet Basis Set Method

    NASA Astrophysics Data System (ADS)

    Lombardini, Richard; Nowara, Ewa; Johnson, Bruce

    2015-03-01

    The use of an orthogonal wavelet basis set (Optimized Maximum-N Generalized Coiflets) to effectively model physical systems in the time domain, in particular the electromagnetic (EM) pulse and quantum mechanical (QM) wavefunction, is examined in this work. Although past research has demonstrated the benefits of wavelet basis sets to handle computationally expensive problems due to their multiresolution properties, the overlapping supports of neighboring wavelet basis functions poses problems when dealing with boundary conditions, especially with material interfaces in the EM case. Specifically, this talk addresses this issue using the idea of derivative matching creating fictitious grid points (T.A. Driscoll and B. Fornberg), but replaces the latter element with fictitious wavelet projections in conjunction with wavelet reconstruction filters. Two-dimensional (2D) systems are analyzed, EM pulse incident on silver cylinders and the QM electron wave packet circling the proton in a hydrogen atom system (reduced to 2D), and the new wavelet method is compared to the popular finite-difference time-domain technique.

  14. Atomic self-consistent-field program by the basis set expansion method: Columbus version

    NASA Astrophysics Data System (ADS)

    Pitzer, Russell M.

    2005-08-01

    A revised and extended (Columbus) version of the Chicago atomic self-consistent-field (Hartree-Fock) program of 1963 is described. Its principal present use is in developing Gaussian basis sets for molecular calculations. Complete memory allocation (using Fortran 90) has been added as well as improved integral formulas and efficient and simple programming features. Energy-expression coefficients have been added sufficient to treat the ground states of all atoms to the extent that Russell-Saunders (LS) coupling applies. Excited states with large angular-momentum orbitals can be treated. Relativistic effects can be included to the extent possible with relativistic effective core potentials. A review of earlier work is included. Program summaryProgram title: atmscf Catalogue identifier: ADVR Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVR Program available from: CPC Program Library, Queen's University of Belfast, N. Ireland Programming language: Fortran 90 Computer: Sun, SGI, PC Operating system: Solaris, Irix, Linux RAM: 10 Mbytes No. of lines in distributed program, including test data, etc.: 2113 No. of bytes in distributed program, including test data, etc.: 15 379 Distribution format: tar.gz Nature of problem: Energies and wave functions, at the Hartree-Fock level Solution method: Expansions in Gaussian or Slater functions. Iterative minimization of the total energy. Optimization of exponential parameters. Used frequently for developing Gaussian basis sets for molecular use Running time: Typical 30 s per calculation

  15. Semi-Automated Detection of Surface Degradation on Bridges Based on a Level Set Method

    NASA Astrophysics Data System (ADS)

    Masiero, A.; Guarnieri, A.; Pirotti, F.; Vettore, A.

    2015-08-01

    Due to the effect of climate factors, natural phenomena and human usage, buildings and infrastructures are subject of progressive degradation. The deterioration of these structures has to be monitored in order to avoid hazards for human beings and for the natural environment in their neighborhood. Hence, on the one hand, monitoring such infrastructures is of primarily importance. On the other hand, unfortunately, nowadays this monitoring effort is mostly done by expert and skilled personnel, which follow the overall data acquisition, analysis and result reporting process, making the whole monitoring procedure quite expensive for the public (and private, as well) agencies. This paper proposes the use of a partially user-assisted procedure in order to reduce the monitoring cost and to make the obtained result less subjective as well. The developed method relies on the use of images acquired with standard cameras by even inexperienced personnel. The deterioration on the infrastructure surface is detected by image segmentation based on a level sets method. The results of the semi-automated analysis procedure are remapped on a 3D model of the infrastructure obtained by means of a terrestrial laser scanning acquisition. The proposed method has been successfully tested on a portion of a road bridge in Perarolo di Cadore (BL), Italy.

  16. Scoring Methods for Building Genotypic Scores: An Application to Didanosine Resistance in a Large Derivation Set

    PubMed Central

    Houssaini, Allal; Assoumou, Lambert; Miller, Veronica; Calvez, Vincent; Marcelin, Anne-Geneviève; Flandre, Philippe

    2013-01-01

    Background Several attempts have been made to determine HIV-1 resistance from genotype resistance testing. We compare scoring methods for building weighted genotyping scores and commonly used systems to determine whether the virus of a HIV-infected patient is resistant. Methods and Principal Findings Three statistical methods (linear discriminant analysis, support vector machine and logistic regression) are used to determine the weight of mutations involved in HIV resistance. We compared these weighted scores with known interpretation systems (ANRS, REGA and Stanford HIV-db) to classify patients as resistant or not. Our methodology is illustrated on the Forum for Collaborative HIV Research didanosine database (N = 1453). The database was divided into four samples according to the country of enrolment (France, USA/Canada, Italy and Spain/UK/Switzerland). The total sample and the four country-based samples allow external validation (one sample is used to estimate a score and the other samples are used to validate it). We used the observed precision to compare the performance of newly derived scores with other interpretation systems. Our results show that newly derived scores performed better than or similar to existing interpretation systems, even with external validation sets. No difference was found between the three methods investigated. Our analysis identified four new mutations associated with didanosine resistance: D123S, Q207K, H208Y and K223Q. Conclusions We explored the potential of three statistical methods to construct weighted scores for didanosine resistance. Our proposed scores performed at least as well as already existing interpretation systems and previously unrecognized didanosine-resistance associated mutations were identified. This approach could be used for building scores of genotypic resistance to other antiretroviral drugs. PMID:23555613

  17. Methods for intraoperative, sterile pose-setting of patient-specific microstereotactic frames

    NASA Astrophysics Data System (ADS)

    Vollmann, Benjamin; Müller, Samuel; Kundrat, Dennis; Ortmaier, Tobias; Kahrs, Lüder A.

    2015-03-01

    This work proposes new methods for a microstereotactic frame based on bone cement fixation. Microstereotactic frames are under investigation for minimal invasive temporal bone surgery, e.g. cochlear implantation, or for deep brain stimulation, where products are already on the market. The correct pose of the microstereotactic frame is either adjusted outside or inside the operating room and the frame is used for e.g. drill or electrode guidance. We present a patientspecific, disposable frame that allows intraoperative, sterile pose-setting. Key idea of our approach is bone cement between two plates that cures while the plates are positioned with a mechatronics system in the desired pose. This paper includes new designs of microstereotactic frames, a system for alignment and first measurements to analyze accuracy and applicable load.

  18. Effective gene selection method with small sample sets using gradient-based and point injection techniques.

    PubMed

    Huang, D; Chow, Tommy W S

    2007-01-01

    Microarray gene expression data usually consist of a large amount of genes. Among these genes, only a small fraction is informative for performing cancer diagnostic test. This paper focuses on effective identification of informative genes. We analyze gene selection models from the perspective of optimization theory. As a result, a new strategy is designed to modify conventional search engines. Also, as overfitting is likely to occur in microarray data because of their small sample set, a point injection technique is developed to address the problem of overfitting. The proposed strategies have been evaluated on three kinds of cancer diagnosis. Our results show that the proposed strategies can improve the performance of gene selection substantially. The experimental results also indicate that the proposed methods are very robust under all the investigated cases. PMID:17666766

  19. A method for testing railway wheel sets on a full-scale roller rig

    NASA Astrophysics Data System (ADS)

    Liu, Binbin; Bruni, Stefano

    2015-09-01

    Full-scale roller rigs for tests on a single axle enable the investigation of several dynamics and durability problems related with the design and operation of the railway rolling stock. In order to exploit the best potential of this test equipment, appropriate test procedures need to be defined, particularly in terms of actuators' references, to make sure that meaningful wheel -rail contact conditions can be reproduced. The aim of this paper is to propose a new methodology to define the forces to be generated by the actuators in the rig in order to best reproduce the behaviour of a wheel set and especially the wheel -rail contact forces in a running condition of interest as obtained either from multi-body system (MBS) simulation or from on-track measurements. The method is supported by the use of a mathematical model of the roller rig and uses an iterative correction scheme, comparing the time histories of the contact force components from the roller rig test as predicted by the mathematical model to a set of target contact force time histories. Two methods are introduced, the first one considering a standard arrangement of the roller rig, the second one assuming that a differential gear is introduced in the rig, allowing different rolling speeds of the two rollers. Results are presented showing that the deviation of the roller rig test results from the considered targets can be kept within low tolerances (1% approximately) as far as the vertical and lateral contact forces on both wheels are concerned. For the longitudinal forces, larger deviations are obtained except in the case where a differential gear is introduced.

  20. Progress and gaps in reproductive health services in three humanitarian settings: mixed-methods case studies

    PubMed Central

    2015-01-01

    Background Reproductive health (RH) care is an essential component of humanitarian response. Women and girls living in humanitarian settings often face high maternal mortality and are vulnerable to unwanted pregnancy, unsafe abortion, and sexual violence. This study explored the availability and quality of, and access barriers to RH services in three humanitarian settings in Burkina Faso, Democratic Republic of the Congo (DRC), and South Sudan. Methods Data collection was conducted between July and October 2013. In total, 63 purposively selected health facilities were assessed: 28 in Burkina Faso, 25 in DRC, and nine in South Sudan, and 42 providers completed a questionnaire to assess RH knowledge and attitudes. Thirty-four focus group discussions were conducted with 29 members of the host communities and 273 displaced married and unmarried women and men to understand access barriers. Results All facilities reported providing some RH services in the prior three months. Five health facilities in Burkina Faso, six in DRC, and none in South Sudan met the criteria as a family planning service delivery point. Two health facilities in Burkina Faso, one in DRC, and two in South Sudan met the criteria as an emergency obstetric and newborn care service delivery point. Across settings, three facilities in DRC adequately provided selected elements of clinical management of rape. Safe abortion was unavailable. Many providers lacked essential knowledge and skills. Focus groups revealed limited knowledge of available RH services and socio-cultural barriers to accessing them, although participants reported a remarkable increase in use of facility-based delivery services. Conclusion Although RH services are being provided, the availability of good quality RH services was inconsistent across settings. Commodity management and security must be prioritized to ensure consistent availability of essential supplies. It is critical to improve the attitudes, managerial and technical

  1. Balancing acts: A mixed methods study of the figured world of African American 7th graders in urban science classrooms

    NASA Astrophysics Data System (ADS)

    Cleveland-Solomon, Tanya E.

    What beliefs and cultural models do youth who are underrepresented in science have about the domain of science and about themselves as science learners? What do they imagine is possible for them in relation to science both now and in the future? In other words, what constitutes their figured world of science? This dissertation study, using a mixed methods design, offers new perspectives on the ways that underrepresented youth's unexamined assumptions or cultural models and resources may shape their identities and motivation to learn science. Through analyses of survey and interview data, I found that urban African American youths' social context, gender, racial identity, and perceptions of the science they had in school influenced their motivation to learn science. Analyses of short-term classroom observations and interviews suggested that students had competing cultural models that they used in their constructions of identities as science learners, which they espoused and adopted in relation to how well they leveraged the science-related cultural resources available to them. Results from this study suggested that these 7th graders would benefit from access to more expansive cultural models through access to individuals with scientific capital as a way to allow them to create fruitful identities as science learners. If we want to ensure that students from groups that are underrepresented in science not only have better outcomes, but aspire to and enter the science career pipeline, we must also begin to support them in their negotiations of competing cultural models that limit their ability to adopt science-learner identities in their classrooms. This study endeavored to understand the particular cultural models and motivational beliefs that drive students to act, and what types of individuals they imagine scientists and science workers to be. This study also examined how cultural models and resources influence identity negotiation, specifically the roles youths

  2. Design and methods for evaluating an early childhood obesity prevention program in the childcare center setting

    PubMed Central

    2013-01-01

    Background Many unhealthy dietary and physical activity habits that foster the development of obesity are established by the age of five. Presently, approximately 70 percent of children in the United States are currently enrolled in early childcare facilities, making this an ideal setting to implement and evaluate childhood obesity prevention efforts. We describe here the methods for conducting an obesity prevention randomized trial in the child care setting. Methods/design A randomized, controlled obesity prevention trial is currently being conducted over a three year period (2010-present). The sample consists of 28 low-income, ethnically diverse child care centers with 1105 children (sample is 60% Hispanic, 15% Haitian, 12% Black, 2% non-Hispanic White and 71% of caregivers were born outside of the US). The purpose is to test the efficacy of a parent and teacher role-modeling intervention on children’s nutrition and physical activity behaviors. . The Healthy Caregivers-Healthy Children (HC2) intervention arm schools received a combination of (1) implementing a daily curricula for teachers/parents (the nutritional gatekeepers); (2) implementing a daily curricula for children; (3) technical assistance with meal and snack menu modifications such as including more fresh and less canned produce; and (4) creation of a center policy for dietary requirements for meals and snacks, physical activity and screen time. Control arm schools received an attention control safety curriculum. Major outcome measures include pre-post changes in child body mass index percentile and z score, fruit and vegetable and other nutritious food intake, amount of physical activity, and parental nutrition and physical activity knowledge, attitudes, and beliefs, defined by intentions and behaviors. All measures were administered at the beginning and end of the school year for year one and year two of the study for a total of 4 longitudinal time points for assessment. Discussion Although few

  3. Redefining racial residential segregation and its association with physical activity among African Americans 50 years and older: a mixed methods approach.

    PubMed

    Armstrong-Brown, Janell; Eng, Eugenia; Hammond, Wizdom Powell; Zimmer, Catherine; Bowling, J Michael

    2015-04-01

    Physical inactivity is one of the factors contributing to disproportionate disease rates among older African Americans. Previous literature indicates that older African Americans are more likely to live in racially segregated neighborhoods and that racial residential segregation is associated with limited opportunities for physical activity. A cross-sectional mixed methods study was conducted guided by the concept of therapeutic landscapes. Multilevel regression analyses demonstrated that racial residential segregation was associated with more minutes of physical activity and greater odds of meeting physical activity recommendations. Qualitative interviews revealed the following physical activity related themes: aging of the neighborhood, knowing your neighbors, feeling of safety, and neighborhood racial identity. Perceptions of social cohesion enhanced participants' physical activity, offering a plausible explanation to the higher rates of physical activity found in this population. Understanding how social cohesion operates within racially segregated neighborhoods can help to inform the design of effective interventions for this population. PMID:24812201

  4. Comparison of several BHT correction methods: a case study on an Australian data set

    NASA Astrophysics Data System (ADS)

    Goutorbe, Bruno; Lucazeau, Francis; Bonneville, Alain

    2007-08-01

    Bottom-hole temperatures (BHT) from oil exploration provide useful constraints on the subsurface thermal regime, but they need to be corrected to obtain the equilibrium temperature. In this work, we introduce several BHT correction methods and compare them using a large Australian data set of more than 650 groups of multiple BHT measurements in about 300 oil exploration boreholes. Existing and suggested corrections are classified within a coherent framework, in which methods are divided into: line/cylinder source; instantaneous/continuous heat extraction; one/two component(s). Comparisons with reservoir test temperatures show that most of the corrections lead to reliable estimates of the formation equilibrium temperature within +/-10°C, but too few data exist to perform an intercomparison of the models based on this criterion. As expected, the Horner method diverges from its parent models for small elapsed times (or equivalently large radii). The mathematical expression of line source models suffers from an unphysical delay time that also restrains their domain of applicability. The model that takes into account the difference of thermal properties between circulating mud and surrounding rocks-that is the two-component model-is delicate to use because of its high complexity. For these reasons, our preferred correction methods are the cylindrical source models. We show that mud circulation time below 10 hr has a negligible effect. The cylindrical source models rely on one parameter depending on the thermal diffusivity and the borehole radius, which are poorly constrained, but the induced uncertainty on the extrapolations remains reasonably low.

  5. Emerging analytical methods to determine gluten markers in processed foods—method development in support of standard setting

    PubMed Central

    Weber, Dorcas; Cléroux, Chantal

    2009-01-01

    The availability of analytical methods to detect and determine levels of markers of priority allergens in foods is of the utmost importance to support standard setting initiatives, the development of compliance and enforcement activities, as well as to provide guidance to industry on implementation of quality control practices, ensuring the effectiveness of allergen-related sanitation techniques. This paper describes the development and implementation of a mass-spectrometry-based technique to determine markers for individual sources of gluten in beer products. This methodology was shown to answer the requirements of Health Canada’s proposed labeling standard for individual gluten source declaration, in order to achieve its policy objectives (i.e., protection of sensitive consumers, while promoting choice). Minimal sample work-up was required and the results obtained by ELISA were further complemented using the LC-MS/MS method. This paper aims to demonstrate the feasibility of alternative techniques to ELISA-based methodologies to determine allergen and gluten markers in food. PMID:19636545

  6. Governance of professional nursing practice in a hospital setting: a mixed methods study1

    PubMed Central

    dos Santos, José Luís Guedes; Erdmann, Alacoque Lorenzini

    2015-01-01

    Objective: to elaborate an interpretative model for the governance of professional nursing practice in a hospital setting. Method: a mixed methods study with concurrent triangulation strategy, using data from a cross-sectional study with 106 nurses and a Grounded Theory study with 63 participants. The quantitative data were collected through the Brazilian Nursing Work Index - Revised and underwent descriptive statistical analysis. Qualitative data were obtained from interviews and analyzed through initial, selective and focused coding. Results: based on the results obtained with the Brazilian Nursing Work Index - Revised, it is possible to state that nurses perceived that they had autonomy, control over the environment, good relationships with physicians and organizational support for nursing governance. The governance of the professional nursing practice is based on the management of nursing care and services carried out by the nurses. To perform these tasks, nurses aim to get around the constraints of the organizational support and develop management knowledge and skills. Conclusion: it is important to reorganize the structures and processes of nursing governance, especially the support provided by the organization for the management practices of nurses. PMID:26625992

  7. On estimating frequency response function envelopes using the spectral element method and fuzzy sets

    NASA Astrophysics Data System (ADS)

    Nunes, R. F.; Klimke, A.; Arruda, J. R. F.

    2006-04-01

    The influence of uncertain input data on response spectra of dynamic structures is considered. Traditionally, frequency response analyses are based on finite or boundary element models of the objective structure. In the case of the mid-frequency range problem, however, a very fine mesh is required to correctly approximate the frequency response. This is particularly problematic in uncertainty modeling where the computational effort is usually increased significantly by the need for multiple runs (e.g. when conducting a Monte Carlo analysis) to achieve reliable results. In this paper, the spectral element method, combined with a fuzzy set-based uncertainty modeling approach, is presented as an appealing alternative, provided that the models are simple enough to yield a spectral element representation. To conduct the fuzzy analysis part, three different implementations of the extension principle of fuzzy arithmetic are applied and compared. The suitability of each method depends on the number of uncertain parameters, the problem characteristics, and the required accuracy of the results. The performance of the proposed approach is illustrated by two test problems, a simple coupled rod and a reinforced plate model. To verify the fuzzy-valued results, a Monte Carlo simulation has also been included.

  8. Measurement of thermally ablated lesions in sonoelastographic images using level set methods

    NASA Astrophysics Data System (ADS)

    Castaneda, Benjamin; Tamez-Pena, Jose Gerardo; Zhang, Man; Hoyt, Kenneth; Bylund, Kevin; Christensen, Jared; Saad, Wael; Strang, John; Rubens, Deborah J.; Parker, Kevin J.

    2008-03-01

    The capability of sonoelastography to detect lesions based on elasticity contrast can be applied to monitor the creation of thermally ablated lesion. Currently, segmentation of lesions depicted in sonoelastographic images is performed manually which can be a time consuming process and prone to significant intra- and inter-observer variability. This work presents a semi-automated segmentation algorithm for sonoelastographic data. The user starts by planting a seed in the perceived center of the lesion. Fast marching methods use this information to create an initial estimate of the lesion. Subsequently, level set methods refine its final shape by attaching the segmented contour to edges in the image while maintaining smoothness. The algorithm is applied to in vivo sonoelastographic images from twenty five thermal ablated lesions created in porcine livers. The estimated area is compared to results from manual segmentation and gross pathology images. Results show that the algorithm outperforms manual segmentation in accuracy, inter- and intra-observer variability. The processing time per image is significantly reduced.

  9. Research on the feature set construction method for spherical stereo vision

    NASA Astrophysics Data System (ADS)

    Zhu, Junchao; Wan, Li; Röning, Juha; Feng, Weijia

    2015-01-01

    Spherical stereo vision is a kind of stereo vision system built by fish-eye lenses, which discussing the stereo algorithms conform to the spherical model. Epipolar geometry is the theory which describes the relationship of the two imaging plane in cameras for the stereo vision system based on perspective projection model. However, the epipolar in uncorrected fish-eye image will not be a line but an arc which intersects at the poles. It is polar curve. In this paper, the theory of nonlinear epipolar geometry will be explored and the method of nonlinear epipolar rectification will be proposed to eliminate the vertical parallax between two fish-eye images. Maximally Stable Extremal Region (MSER) utilizes grayscale as independent variables, and uses the local extremum of the area variation as the testing results. It is demonstrated in literatures that MSER is only depending on the gray variations of images, and not relating with local structural characteristics and resolution of image. Here, MSER will be combined with the nonlinear epipolar rectification method proposed in this paper. The intersection of the rectified epipolar and the corresponding MSER region is determined as the feature set of spherical stereo vision. Experiments show that this study achieved the expected results.

  10. Elliptical tiling method to generate a 2-dimensional set of templates for gravitational wave search

    NASA Astrophysics Data System (ADS)

    Arnaud, Nicolas; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Kreckelbergh, Stephane; Porter, Edward K.

    2003-05-01

    Searching for a signal depending on unknown parameters in a noisy background with matched filtering techniques always requires an analysis of the data with several templates in parallel in order to ensure a proper match between the filter and the real waveform. The key feature of such an implementation is the design of the filter bank which must be small to limit the computational cost while keeping the detection efficiency as high as possible. This paper presents a geometrical method that allows one to cover the corresponding physical parameter space by a set of ellipses, each of them being associated with a given template. After the description of the main characteristics of the algorithm, the method is applied in the field of gravitational wave (GW) data analysis, for the search of damped sine signals. Such waveforms are expected to be produced during the deexcitation phase of black holes—the so-called “ringdown” signals—and are also encountered in some numerically computed supernova signals. First, the number of templates N computed by the method is similar to its analytical estimation, despite the overlaps between neighbor templates and the border effects. Moreover, N is small enough to test for the first time the performances of the set of templates for different choices of the minimal match MM, the parameter used to define the maximal allowed loss of signal-to-noise ratio (SNR) due to the mismatch between real signals and templates. The main result of this analysis is that the fraction of SNR recovered is on average much higher than MM, which dramatically decreases the mean percentage of false dismissals. Indeed, it goes well below its estimated value of 1-MM3 used as input of the algorithm. Thus, as this feature should be common to any tiling algorithm, it seems possible to reduce the constraint on the value of MM—and indeed the number of templates and the computing power—without losing as many events as expected on

  11. Investigation of optimal feature value set in false positive reduction process for automated abdominal lymph node detection method

    NASA Astrophysics Data System (ADS)

    Nakamura, Yoshihiko; Nimura, Yukitaka; Kitasaka, Takayuki; Mizuno, Shinji; Furukawa, Kazuhiro; Goto, Hidemi; Fujiwara, Michitaka; Misawa, Kazunari; Ito, Masaaki; Nawano, Shigeru; Mori, Kensaku

    2015-03-01

    This paper presents an investigation of optimal feature value set in false positive reduction process for the automated method of enlarged abdominal lymph node detection. We have developed the automated abdominal lymph node detection method to aid for surgical planning. Because it is important to understand the location and the structure of an enlarged lymph node in order to make a suitable surgical plan. However, our previous method was not able to obtain the suitable feature value set. This method was able to detect 71.6% of the lymph nodes with 12.5 FPs per case. In this paper, we investigate the optimal feature value set in the false positive reduction process to improve the method for automated abdominal lymph node detection. By applying our improved method by using the optimal feature value set to 28 cases of abdominal 3D CT images, we detected about 74.7% of the abdominal lymph nodes with 11.8 FPs/case.

  12. High-Order Discontinuous Galerkin Level Set Method for Interface Tracking and Re-Distancing on Unstructured Meshes

    NASA Astrophysics Data System (ADS)

    Greene, Patrick; Nourgaliev, Robert; Schofield, Sam

    2015-11-01

    A new sharp high-order interface tracking method for multi-material flow problems on unstructured meshes is presented. The method combines the marker-tracking algorithm with a discontinuous Galerkin (DG) level set method to implicitly track interfaces. DG projection is used to provide a mapping from the Lagrangian marker field to the Eulerian level set field. For the level set re-distancing, we developed a novel marching method that takes advantage of the unique features of the DG representation of the level set. The method efficiently marches outward from the zero level set with values in the new cells being computed solely from cell neighbors. Results are presented for a number of different interface geometries including ones with sharp corners and multiple hierarchical level sets. The method can robustly handle the level set discontinuities without explicit utilization of solution limiters. Results show that the expected high order (3rd and higher) of convergence for the DG representation of the level set is obtained for smooth solutions on unstructured meshes. High-order re-distancing on irregular meshes is a must for applications were the interfacial curvature is important for underlying physics, such as surface tension, wetting and detonation shock dynamics. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Information management release number LLNL-ABS-675636.

  13. A-type magmatism in a syn-collisional setting: The case of the Pan-African Hook Batholith in Central Zambia

    NASA Astrophysics Data System (ADS)

    Milani, Lorenzo; Lehmann, Jérémie; Naydenov, Kalin V.; Saalmann, Kerstin; Kinnaird, Judith A.; Daly, J. Stephen; Frei, Dirk; Lobo-Guerrero Sanz, Alberto

    2015-02-01

    The Pan-African Hook Batholith formed during the assembly of the Gondwana supercontinent as a result of syn-collisional stage interaction between the Congo and Kalahari Cratons. The bimodal magmatism (mafic to predominantly felsic) is characterized by both an alkali-calcic and an alkalic suite, with typical A-type, metaluminous, high Fe/Mg and K/Na geochemical signature. Occasionally, sodic granitoids have been documented. Compositions were driven to more differentiated products by fractional crystallization, while Sr-Nd isotopes exclude crustal assimilation during crystallization. Recent new U-Pb age data constrain most of the felsic magmatism between 550 and 540 Ma. Scattered outcrops of gabbroic rocks, both tholeiitic and alkaline, testify to periodic input of mantle material, and, in some cases, to interaction with metasomatizing fluids. Crystallization ages on mafic rocks span from 570 to 520 Ma, thus indicating that they were contemporaneous with the major granitic intrusion, which was the result of a number of successive felsic batches, eventually forming a coalescing batholith. Highly radiogenic Pb isotopic values attest to the radiogenic character of the rocks. Such an anomalous signature was acquired during, or soon after, magma emplacement, perhaps as result of metasomatizing fluids. Enrichment in Th-U of large portions of the crust along this part of the margin of the Congo Craton is suggested. Geochemical and isotopic evidence support the interaction between mantle components and portions of the deep crust at pressure of < 10 kbar, while decompression melting of rising asthenospheric mantle ponding at the base of the crust heated, and ultimately melted, crustal material. An additional and crucial contribution to the crustal melting was likely provided by internal radiogenic heat production of the thickened crust, and is in agreement with the high radioactivity of the pluton. A tectono-thermal model, implying crustal accretion accompanied by slab

  14. Methods for comparing beebread made by Africanized and European honey bees and the effects on hemolymph protein titers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of genotype on the conversion of pollen to beebread and on the ability of bees to acquire protein from it was examined using European and Africanized honey bees (EHB and AHB respectively). Both subspecies were provided with the same pollen source. Pollen stored and converted to beebr...

  15. Comparison of Web-Based and Face-to-Face Standard Setting Using the Angoff Method

    ERIC Educational Resources Information Center

    Katz, Irvin R.; Tannenbaum, Richard J.

    2014-01-01

    Web-based standard setting holds promise for reducing the travel and logistical inconveniences of traditional, face-to-face standard setting meetings. However, because there are few published reports of setting standards via remote meeting technology, little is known about the practical potential of the approach, including technical feasibility of…

  16. An abdominal aortic aneurysm segmentation method: Level set with region and statistical information

    SciTech Connect

    Zhuge Feng; Rubin, Geoffrey D.; Sun Shaohua; Napel, Sandy

    2006-05-15

    We present a system for segmenting the human aortic aneurysm in CT angiograms (CTA), which, in turn, allows measurements of volume and morphological aspects useful for treatment planning. The system estimates a rough 'initial surface', and then refines it using a level set segmentation scheme augmented with two external analyzers: The global region analyzer, which incorporates a priori knowledge of the intensity, volume, and shape of the aorta and other structures, and the local feature analyzer, which uses voxel location, intensity, and texture features to train and drive a support vector machine classifier. Each analyzer outputs a value that corresponds to the likelihood that a given voxel is part of the aneurysm, which is used during level set iteration to control the evolution of the surface. We tested our system using a database of 20 CTA scans of patients with aortic aneurysms. The mean and worst case values of volume overlap, volume error, mean distance error, and maximum distance error relative to human tracing were 95.3%{+-}1.4% (s.d.); worst case=92.9%, 3.5%{+-}2.5% (s.d.); worst case=7.0%, 0.6{+-}0.2 mm (s.d.); worst case=1.0 mm, and 5.2{+-}2.3mm (s.d.); worstcase=9.6 mm, respectively. When implemented on a 2.8 GHz Pentium IV personal computer, the mean time required for segmentation was 7.4{+-}3.6min (s.d.). We also performed experiments that suggest that our method is insensitive to parameter changes within 10% of their experimentally determined values. This preliminary study proves feasibility for an accurate, precise, and robust system for segmentation of the abdominal aneurysm from CTA data, and may be of benefit to patients with aortic aneurysms.

  17. Gliding Box method applied to trace element distribution of a geochemical data set

    NASA Astrophysics Data System (ADS)

    Paz González, Antonio; Vidal Vázquez, Eva; Rosario García Moreno, M.; Paz Ferreiro, Jorge; Saa Requejo, Antonio; María Tarquis, Ana

    2010-05-01

    The application of fractal theory to process geochemical prospecting data can provide useful information for evaluating mineralization potential. A geochemical survey was carried out in the west area of Coruña province (NW Spain). Major elements and trace elements were determined by standard analytical techniques. It is well known that there are specific elements or arrays of elements, which are associated with specific types of mineralization. Arsenic has been used to evaluate the metallogenetic importance of the studied zone. Moreover, as can be considered as a pathfinder of Au, as these two elements are genetically associated. The main objective of this study was to use multifractal analysis to characterize the distribution of three trace elements, namely Au, As, and Sb. Concerning the local geology, the study area comprises predominantly acid rocks, mainly alkaline and calcalkaline granites, gneiss and migmatites. The most significant structural feature of this zone is the presence of a mylonitic band, with an approximate NE-SW orientation. The data set used in this study comprises 323 samples collected, with standard geochemical criteria, preferentially in the B horizon of the soil. Occasionally where this horizon was not present, samples were collected from the C horizon. Samples were taken in a rectilinear grid. The sampling lines were perpendicular to the NE-SW tectonic structures. Frequency distributions of the studied elements departed from normal. Coefficients of variation ranked as follows: Sb < As < Au. Significant correlation coefficients between Au, Sb, and As were found, even if these were low. The so-called ‘gliding box' algorithm (GB) proposed originally for lacunarity analysis has been extended to multifractal modelling and provides an alternative to the ‘box-counting' method for implementing multifractal analysis. The partitioning method applied in GB algorithm constructs samples by gliding a box of certain size (a) over the grid map in all

  18. Parameters influencing the location and characteristics of volcanic eruptions in a youthful extensional setting: Insights from the Virunga Volcanic Province, in the Western Branch of the East African Rift System

    NASA Astrophysics Data System (ADS)

    Smets, Benoît; d'Oreye, Nicolas; Kervyn, Matthieu; Kervyn, François

    2016-04-01

    The East African Rift System (EARS) is often mentioned as the modern archetype for rifting and continental break-up (Calais et al., 2006, GSL Special Publication 259), showing the complex interaction between rift faults, magmatism and pre-existing structures of the basement. Volcanism in the EARS is characterized by very active volcanoes, several of them being among the most active on Earth (Wright et al., 2015, GRL 42). Such intense volcanic activity provides useful information to study the relationship between rifting, magmatism and volcanism. This is the case of the Virunga Volcanic Province (VVP) located in the central part of the Western Branch of the EARS, which hosts two of the most active African volcanoes, namely Nyiragongo and Nyamulagira. Despite the intense eruptive activity in the VVP, the spatial distribution of volcanism and its relationship with the extensional setting remain little known. Here we present a study of the interaction between tectonics, magmatism and volcanism at the scale of the Kivu rift section, where the VVP is located, and at the scale of a volcano, by studying the dense historical eruptive activity of Nyamulagira. Both the complex Precambrian basement and magmatism appear to contribute to the development of the Kivu rift. The presence of transfer zones north and south of the Lake Kivu rift basin favoured the development of volcanic provinces at these locations. Rift faults, including reactivated Precambrian structures influenced the location of volcanism within the volcanic provinces and the rift basin. At a more local scale, the historical eruptive activity of Nyamulagira highlights that, once a composite volcano developed, the gravitational stress field induced by edifice loading becomes the main parameter that influence the location, duration and lava volume of eruptions.

  19. An efficient out-of-core volume ray casting method for the visualization of large medical data sets

    NASA Astrophysics Data System (ADS)

    Xue, Jian; Tian, Jie; Chen, Jian; Dai, Yakang

    2007-03-01

    Volume ray casting algorithm is widely recognized for high quality volume visualization. However, when rendering very large volume data sets, the original ray casting algorithm will lead to very inefficient random accesses in disk and make it very slowly to render the whole volume data set. In order to solve this problem, an efficient out-of-core volume ray casting method with a new out-of-core framework for processing large volume data sets based on consumer PC hardware is proposed in this paper. The new framework gives a transparent and efficient access to the volume data set cached in disk, while the new volume ray casting method minimizes the data exchange between hard disk and physical memory and performs comparatively fast high quality volume rendering. The experimental results indicate that the new method and framework are effective and efficient for the visualization of very large medical data sets.

  20. Refined microdialysis method for protein biomarker sampling in acute brain injury in the neurointensive care setting.

    PubMed

    Dahlin, Andreas P; Purins, Karlis; Clausen, Fredrik; Chu, Jiangtao; Sedigh, Amir; Lorant, Tomas; Enblad, Per; Lewén, Anders; Hillered, Lars

    2014-09-01

    There is growing interest in cerebral microdialysis (MD) for sampling of protein biomarkers in neurointensive care (NIC) patients. Published data point to inherent problems with this methodology including protein interaction and biofouling leading to unstable catheter performance. This study tested the in vivo performance of a refined MD method including catheter surface modification, for protein biomarker sampling in a clinically relevant porcine brain injury model. Seven pigs of both sexes (10-12 weeks old; 22.2-27.3 kg) were included. Mean arterial blood pressure, heart rate, intracranial pressure (ICP) and cerebral perfusion pressure was recorded during the stepwise elevation of intracranial pressure by inflation of an epidural balloon catheter with saline (1 mL/20 min) until brain death. One naïve MD catheter and one surface modified with Pluronic F-127 (10 mm membrane, 100 kDa molecular weight cutoff MD catheter) were inserted into the right frontal cortex and perfused with mock CSF with 3% Dextran 500 at a flow rate of 1.0 μL/min and 20 min sample collection. Naïve catheters showed unstable fluid recovery, sensitive to ICP changes, which was significantly stabilized by surface modification. Three of seven naïve catheters failed to deliver a stable fluid recovery. MD levels of glucose, lactate, pyruvate, glutamate, glycerol and urea measured enzymatically showed an expected gradual ischemic and cellular distress response to the intervention without differences between naïve and surface modified catheters. The 17 most common proteins quantified by iTRAQ and nanoflow LC-MS/MS were used as biomarker models. These proteins showed a significantly more homogeneous response to the ICP intervention in surface modified compared to naïve MD catheters with improved extraction efficiency for most of the proteins. The refined MD method appears to improve the accuracy and precision of protein biomarker sampling in the NIC setting. PMID:25075428

  1. The structure and material composition of ossified aortic valves identified using a set of scientific methods

    NASA Astrophysics Data System (ADS)

    Zeman, Antonín; Šmíd, Michal; Havelcová, Martina; Coufalová, Lucie; Kučková, Štěpánka; Velčovská, Martina; Hynek, Radovan

    2013-11-01

    Degenerative aortic stenosis has become a common and dangerous disease in recent decades. This disease leads to the mineralization of aortic valves, their gradual thickening and loss of functionality. We studied the detailed assessment of the proportion and composition of inorganic and organic components in the ossified aortic valve, using a set of analytical methods applied in science: polarized light microscopy, scanning electron microscopy, X-ray fluorescence, X-ray diffraction, gas chromatography/mass spectrometry and liquid chromatography-tandem mass spectrometry. The sample valves showed the occurrence of phosphorus and calcium in the form of phosphate and calcium carbonate, hydroxyapatite, fluorapatite and hydroxy-fluorapatite, with varying content of inorganic components from 65 to 90 wt%, and with phased development of degenerative disability. The outer layers of the plaque contained an organic component with peptide bonds, fatty acids, proteins and cholesterol. The results show a correlation between the formation of fluorapatite in aortic valves and in other parts of the human bodies, associated with the formation of bones.

  2. A level set method for solid-liquid interface tracking in texturally equilibrated pore networks

    NASA Astrophysics Data System (ADS)

    Ghanbarzadeh, Soheil; Hesse, Marc; Prodanovic, Masa

    2015-04-01

    The properties of some porous media are determined by their evolution towards textural equilibrium. Melt drainage from temperate glacier ice and the accumulation of hydrocarbons beneath rock salt are two examples in natural systems. In these materials, pore geometry evolves to minimize the solid-liquid interfacial energy while maintaining dihedral angle, θ, at solid-liquid contact lines. In this work we present the first computations of 3-D texturally equilibrated pore networks using a novel level set method. Interfacial energy minimization is achieved by evolving interface under surface diffusion to constant mean curvature surface. The porosity and dihedral angle constraints are added to the formulation using virtual velocity terms. A domain decomposition scheme is devised to restrict the computational domain and the coupling between the interfaces is achieved on the original computational domain. For the last 30 years, explicit representation of the interfaces limited the computations to highly idealized geometries. The presented model overcomes these limitations and opens the door to the exploration of the physics of these materials in realistic systems. For example, our results show that the fully wetted grain boundaries exist even for θ>0 which reconciles the theory with experimental observations. This work is sponsored by the Statoil Fellows Program at The University of Texas.

  3. A Standard Setting Method Designed for Complex Performance Assessments with Multiple Performance Categories: Categorical Assignments of Student Work.

    ERIC Educational Resources Information Center

    Plake, Barbara S.; Hambleton, Ronald K.

    This paper reports on a standard-setting method designed for complex performance assessments with multiple performance categories. The method studied, the Analytical Judgment Method, involves panelists' making analytical classification decisions for each of the test's components individually. It also allows for discussion and reconsideration of…

  4. Inkwari: An Emerging High-Risk Place Potentiating HIV Spread Among Young Adults in a Hyper-Endemic South African Setting

    PubMed Central

    Closson, Elizabeth F.; Safren, Steven A.; Mabude, Zonke; Mosery, Nzwakie; Taylor, Scott W.; Perez-Brumer, Amaya; Matthews, Lynn T.; Psaros, Christina; Harrison, Abigail; Grelotti, David J.; Bangsberg, David R.; Smit, Jennifer A.

    2015-01-01

    Young adults in South Africa are at the epicenter of the HIV epidemic. The prevalence of HIV among young people in the province of KwaZulu-Natal (KZN) is particularly high. This study characterizes inkwari (Zulu word for raves or weekend-long parties) in eThekwini District, KZN and explored how these place-based dynamics shape the risk environment for the young adult attendees. In 2011, 13 qualitative interviews were conducted with men and women between 18 and 30 years-old who reported unprotected sex with at least one casual partner in the prior 3 months and attended an inkwari in the same time period. Interviews were analyzed using qualitative content analysis. Nine key informant interviews helped to triangulate these data. Five women and eight men were interviewed and the mean age was 25 years (SD 3.24). Ten reported meeting a sexual partner at an inkwari. Inkwari were characterized as sexualized settings with limited adult supervision. Participants attended inkwari to socialize with peers, use drugs and alcohol, and meet sexual partners. Sexual and physical violence also occurred at inkwari. Given the convergence of social, sexual, and substance- using networks at inkwari, further inquiry is needed to determine how this place may potentiate HIV transmission risk in an endemic setting. PMID:25091214

  5. A Classification Method of Inquiry E-mails for Describing FAQ with Automatic Setting Mechanism of Judgment Thresholds

    NASA Astrophysics Data System (ADS)

    Tsuda, Yuki; Akiyoshi, Masanori; Samejima, Masaki; Oka, Hironori

    In this paper the authors propose a classification method of inquiry e-mails for describing FAQ (Frequently Asked Questions) and automatic setting mechanism of judgment thresholds. In this method, a dictionary used for classification of inquiries is generated and updated automatically by statistical information of characteristic words in clusters, and inquiries are classified correctly to each proper cluster by using the dictionary. Threshold values are automatically set by using statistical information.

  6. Modeling Primary Breakup: A Three-Dimensional Eulerian Level Set/Vortex Sheet Method for Two-Phase Interface Dynamics

    NASA Technical Reports Server (NTRS)

    Herrmann, M.

    2003-01-01

    This paper is divided into four parts. First, the level set/vortex sheet method for three-dimensional two-phase interface dynamics is presented. Second, the LSS model for the primary breakup of turbulent liquid jets and sheets is outlined and all terms requiring subgrid modeling are identified. Then, preliminary three-dimensional results of the level set/vortex sheet method are presented and discussed. Finally, conclusions are drawn and an outlook to future work is given.

  7. A Qualitative Investigation of Panelists' Experiences of Standard Setting Using Two Variations of the Bookmark Method

    ERIC Educational Resources Information Center

    Hein, Serge F.; Skaggs, Gary E.

    2009-01-01

    Only a small number of qualitative studies have investigated panelists' experiences during standard-setting activities or the thought processes associated with panelists' actions. This qualitative study involved an examination of the experiences of 11 panelists who participated in a prior, one-day standard-setting meeting in which either the…

  8. Expert Consensus on the Rehabilitation Framework Guiding a Model of Care for People Living With HIV in a South African Setting.

    PubMed

    Chetty, Verusia; Hanass-Hancock, Jill; Myezwa, Hellen

    2016-01-01

    Disabilities and treatments related to HIV are a focus for rehabilitation professionals in HIV-endemic countries, yet these countries lack guidance to integrate rehabilitation into a model of care for people living with HIV. We asked HIV and rehabilitation experts in South Africa to engage in a modified Delphi survey based on findings from (a) an enquiry into stakeholder perspectives of a context-specific rehabilitation framework at a semi-rural setting and (b) an analysis of international models of care-guiding rehabilitation. Consensus was determined by an a priori threshold of 70% of agreement and interquartile range (≤ 1 on criterion) to be included as essential or useful in the model of care framework. Experts agreed that improving access to care, optimal communication between stakeholders, education and training for health care workers, and home-based rehabilitation were essential for the model. Furthermore, task shifting and evidence-based practice were seen as fundamental for optimal care. PMID:26585032

  9. Narcolepsy in African Americans

    PubMed Central

    Kawai, Makoto; O'Hara, Ruth; Einen, Mali; Lin, Ling; Mignot, Emmanuel

    2015-01-01

    Study Objectives: Although narcolepsy affects 0.02–0.05% of individuals in various ethnic groups, clinical presentation in different ethnicities has never been fully characterized. Our goal was to study phenotypic expression across ethnicities in the United States. Design/Setting: Cases of narcolepsy from 1992 to 2013 were identified from searches of the Stanford Center for Narcolepsy Research database. International Classification of Sleep Disorders, Third Edition diagnosis criteria for type 1 and type 2 narcolepsy were used for inclusion, but subjects were separated as with and without cataplexy for the purpose of data presentation. Information extracted included demographics, ethnicity and clinical data, HLA-DQB1*06:02, polysomnography (PSG), multiple sleep latency test (MSLT) data, and cerebrospinal fluid (CSF) hypocretin-1 level. Patients: 182 African-Americans, 839 Caucasians, 35 Asians, and 41 Latinos with narcolepsy. Results: Sex ratio, PSG, and MSLT findings did not differ across ethnicities. Epworth Sleepiness Scale (ESS) score was higher and age of onset of sleepiness earlier in African Americans compared with other ethnicities. HLA-DQB1*06:02 positivity was higher in African Americans (91.0%) versus others (76.6% in Caucasians, 80.0% in Asians, and 65.0% in Latinos). CSF hypocretin-1 level, obtained in 222 patients, was more frequently low (≤ 110 pg/ml) in African Americans (93.9%) versus Caucasians (61.5%), Asians (85.7%) and Latinos (75.0%). In subjects with low CSF hypocretin-1, African Americans (28.3%) were 4.5 fold more likely to be without cataplexy when compared with Caucasians (8.1%). Conclusions: Narcolepsy in African Americans is characterized by earlier symptom onset, higher Epworth Sleepiness Scale score, higher HLA-DQB1*06:02 positivity, and low cerebrospinal fluid hypocretin-1 level in the absence of cataplexy. In African Americans, more subjects without cataplexy have type 1 narcolepsy. Citation: Kawai M, O'Hara R, Einen M, Lin L

  10. Angoff Method of Setting Cut Scores for High-Stakes Testing: Foley Catheter Checkoff as an Exemplar.

    PubMed

    Kardong-Edgren, Suzan; Mulcock, Pamela M

    2016-01-01

    The Angoff method is a commonly used and legally defensible method for setting passing or cut scores for high-stakes examinations. It also can be used for setting passing scores on clinical skill checklists. Two variations of the Angoff method were compared with a traditional and arbitrary 75% passing score, using a Foley catheter insertion checklist as an exemplar. Both Angoff methods produced slightly lower scores than our traditional scoring; because of "must pass" steps on our checklist, 12 of 13 students still failed the evaluation. The project uncovered multiple variations of checklists within different courses and variations in teaching practices for this skill. PMID:26402909

  11. Setting health research priorities using the CHNRI method: VI. Quantitative properties of human collective opinion

    PubMed Central

    Yoshida, Sachiyo; Rudan, Igor; Cousens, Simon

    2016-01-01

    Introduction Crowdsourcing has become an increasingly important tool to address many problems – from government elections in democracies, stock market prices, to modern online tools such as TripAdvisor or Internet Movie Database (IMDB). The CHNRI method (the acronym for the Child Health and Nutrition Research Initiative) for setting health research priorities has crowdsourcing as the major component, which it uses to generate, assess and prioritize between many competing health research ideas. Methods We conducted a series of analyses using data from a group of 91 scorers to explore the quantitative properties of their collective opinion. We were interested in the stability of their collective opinion as the sample size increases from 15 to 90. From a pool of 91 scorers who took part in a previous CHNRI exercise, we used sampling with replacement to generate multiple random samples of different size. First, for each sample generated, we identified the top 20 ranked research ideas, among 205 that were proposed and scored, and calculated the concordance with the ranking generated by the 91 original scorers. Second, we used rank correlation coefficients to compare the ranks assigned to all 205 proposed research ideas when samples of different size are used. We also analysed the original pool of 91 scorers to to look for evidence of scoring variations based on scorers' characteristics. Results The sample sizes investigated ranged from 15 to 90. The concordance for the top 20 scored research ideas increased with sample sizes up to about 55 experts. At this point, the median level of concordance stabilized at 15/20 top ranked questions (75%), with the interquartile range also generally stable (14–16). There was little further increase in overlap when the sample size increased from 55 to 90. When analysing the ranking of all 205 ideas, the rank correlation coefficient increased as the sample size increased, with a median correlation of 0.95 reached at the sample size

  12. Ethics and Rationing Access to Dialysis in Resource-Limited Settings: The Consequences of Refusing a Renal Transplant in the South African State Sector.

    PubMed

    Etheredge, Harriet; Paget, Graham

    2015-12-01

    Resource constraints in developing countries compel policy makers to ration the provision of healthcare services. This article examines one such set of Guidelines: A patient dialysing in the state sector in South Africa may not refuse renal transplantation when a kidney becomes available. Refusal of transplantation can lead to exclusion from the state-funded dialysis programme. This Guideline is legally acceptable as related to Constitutional stipulations which allow for rationing healthcare resources in South Africa. Evaluating the ethical merit of the Guideline, and exploring the ethical dilemma it poses, proves a more complex task. We examine the actions of healthcare professionals as constrained by the Guideline. From a best interests framework, we argue that in these circumstances directing patient decision making (pressurising a patient to undergo renal transplantation) is not necessarily unethical or unacceptably paternalistic. We then scrutinise the guideline itself through several different ethical 'lenses'. Here, we argue that bioethics does not provide a definitive answer as to the moral merit of rationing dialysis under these circumstances, however it can be considered just in this context. We conclude by examining a potential pitfall of the Guideline: Unwilling transplant recipients may not comply with immunosuppressive medication, which raises questions for policies based on resource management and rationing. PMID:24953161

  13. Two Methods for Efficient Solution of the Hitting-Set Problem

    NASA Technical Reports Server (NTRS)

    Vatan, Farrokh; Fijany, Amir

    2005-01-01

    A paper addresses much of the same subject matter as that of Fast Algorithms for Model-Based Diagnosis (NPO-30582), which appears elsewhere in this issue of NASA Tech Briefs. However, in the paper, the emphasis is more on the hitting-set problem (also known as the transversal problem), which is well known among experts in combinatorics. The authors primary interest in the hitting-set problem lies in its connection to the diagnosis problem: it is a theorem of model-based diagnosis that in the set-theory representation of the components of a system, the minimal diagnoses of a system are the minimal hitting sets of the system. In the paper, the hitting-set problem (and, hence, the diagnosis problem) is translated from a combinatorial to a computational problem by mapping it onto the Boolean satisfiability and integer- programming problems. The paper goes on to describe developments nearly identical to those summarized in the cited companion NASA Tech Briefs article, including the utilization of Boolean-satisfiability and integer- programming techniques to reduce the computation time and/or memory needed to solve the hitting-set problem.

  14. Setting health research priorities using the CHNRI method: V. Quantitative properties of human collective knowledge

    PubMed Central

    Rudan, Igor; Yoshida, Sachiyo; Wazny, Kerri; Chan, Kit Yee; Cousens, Simon

    2016-01-01

    Introduction The CHNRI method for setting health research priorities has crowdsourcing as the major component. It uses the collective opinion of a group of experts to generate, assess and prioritize between many competing health research ideas. It is difficult to compare the accuracy of human individual and collective opinions in predicting uncertain future outcomes before the outcomes are known. However, this limitation does not apply to existing knowledge, which is an important component underlying opinion. In this paper, we report several experiments to explore the quantitative properties of human collective knowledge and discuss their relevance to the CHNRI method. Methods We conducted a series of experiments in groups of about 160 (range: 122–175) undergraduate Year 2 medical students to compare their collective knowledge to their individual knowledge. We asked them to answer 10 questions on each of the following: (i) an area in which they have a degree of expertise (undergraduate Year 1 medical curriculum); (ii) an area in which they likely have some knowledge (general knowledge); and (iii) an area in which they are not expected to have any knowledge (astronomy). We also presented them with 20 pairs of well–known celebrities and asked them to identify the older person of the pair. In all these experiments our goal was to examine how the collective answer compares to the distribution of students’ individual answers. Results When answering the questions in their own area of expertise, the collective answer (the median) was in the top 20.83% of the most accurate individual responses; in general knowledge, it was in the top 11.93%; and in an area with no expertise, the group answer was in the top 7.02%. However, the collective answer based on mean values fared much worse, ranging from top 75.60% to top 95.91%. Also, when confronted with guessing the older of the two celebrities, the collective response was correct in 18/20 cases (90%), while the 8 most

  15. Standard Setting in a Small Scale OSCE: A Comparison of the Modified Borderline-Group Method and the Borderline Regression Method

    ERIC Educational Resources Information Center

    Wood, Timothy J.; Humphrey-Murto, Susan M.; Norman, Geoffrey R.

    2006-01-01

    When setting standards, administrators of small-scale OSCEs often face several challenges, including a lack of resources, a lack of available expertise in statistics, and difficulty in recruiting judges. The Modified Borderline-Group Method is a standard setting procedure that compensates for these challenges by using physician examiners and is…

  16. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  17. The Effects of Different Standard Setting Methods and the Composition of Borderline Groups: A Study within a Law Curriculum

    ERIC Educational Resources Information Center

    Dochy, Filip; Kyndt, Eva; Baeten, Marlies; Pottier, Sofie; Veestraeten, Marlies; Leuven, K. U.

    2009-01-01

    The aim of this study was to examine the effect of different standard setting methods on the size and composition of the borderline group, on the discrimination between different types of students and on the types of students passing with one method but failing with another. A total of 107 university students were classified into 4 different types…

  18. Understanding Rasch Measurement: A Mapmark Method of Standard Setting as Implemented for the National Assessment Governing Board

    ERIC Educational Resources Information Center

    Schulz, E. Matthew; Mitzel, Howard C.

    2011-01-01

    This article describes a Mapmark standard setting procedure, developed under contract with the National Assessment Governing Board (NAGB). The procedure enhances the bookmark method with spatially representative item maps, holistic feedback, and an emphasis on independent judgment. A rationale for these enhancements, and the bookmark method, is…

  19. Comparing of goal setting strategy with group education method to increase physical activity level: A randomized trial

    PubMed Central

    Jiryaee, Nasrin; Siadat, Zahra Dana; Zamani, Ahmadreza; Taleban, Roya

    2015-01-01

    Background: Designing an intervention to increase physical activity is important to be based on the health care settings resources and be acceptable by the subject group. This study was designed to assess and compare the effect of the goal setting strategy with a group education method on increasing the physical activity of mothers of children aged 1 to 5. Materials and Methods: Mothers who had at least one child of 1-5 years were randomized into two groups. The effect of 1) goal-setting strategy and 2) group education method on increasing physical activity was assessed and compared 1 month and 3 months after the intervention. Also, the weight, height, body mass index (BMI), waist and hip circumference, and well-being were compared between the two groups before and after the intervention. Results: Physical activity level increased significantly after the intervention in the goal-setting group and it was significantly different between the two groups after intervention (P < 0.05). BMI, waist circumference, hip circumference, and well-being score were significantly different in the goal-setting group after the intervention. In the group education method, only the well-being score improved significantly (P < 0.05). Conclusion: Our study presented the effects of using the goal-setting strategy to boost physical activity, improving the state of well-being and decreasing BMI, waist, and hip circumference. PMID:26929765

  20. Population diversity and antibody selective pressure to Plasmodium falciparum MSP1 block2 locus in an African malaria-endemic setting

    PubMed Central

    2009-01-01

    Background Genetic evidence for diversifying selection identified the Merozoite Surface Protein1 block2 (PfMSP1 block2) as a putative target of protective immunity against Plasmodium falciparum. The locus displays three family types and one recombinant type, each with multiple allelic forms differing by single nucleotide polymorphism as well as sequence, copy number and arrangement variation of three amino acid repeats. The family-specific antibody responses observed in endemic settings support immune selection operating at the family level. However, the factors contributing to the large intra-family allelic diversity remain unclear. To address this question, population allelic polymorphism and sequence variant-specific antibody responses were studied in a single Senegalese rural community where malaria transmission is intense and perennial. Results Family distribution showed no significant temporal fluctuation over the 10 y period surveyed. Sequencing of 358 PCR fragments identified 126 distinct alleles, including numerous novel alleles in each family and multiple novel alleles of recombinant types. The parasite population consisted in a large number of low frequency alleles, alongside one high-frequency and three intermediate frequency alleles. Population diversity tests supported positive selection at the family level, but showed no significant departure from neutrality when considering intra-family allelic sequence diversity and all families combined. Seroprevalence, analysed using biotinylated peptides displaying numerous sequence variants, was moderate and increased with age. Reactivity profiles were individual-specific, mapped to the family-specific flanking regions and to repeat sequences shared by numerous allelic forms within a family type. Seroreactivity to K1-, Mad20- and R033 families correlated with the relative family genotype distribution within the village. Antibody specificity remained unchanged with cumulated exposure to an increasingly large

  1. Analytic design method for optimal imaging: coupling three ray sets using two free-form lens profiles.

    PubMed

    Duerr, Fabian; Benítez, Pablo; Miñano, Juan C; Meuret, Youri; Thienpont, Hugo

    2012-02-27

    In this work, a new two-dimensional optics design method is proposed that enables the coupling of three ray sets with two lens surfaces. The method is especially important for optical systems designed for wide field of view and with clearly separated optical surfaces. Fermat's principle is used to deduce a set of functional differential equations fully describing the entire optical system. The presented general analytic solution makes it possible to calculate the lens profiles. Ray tracing results for calculated 15th order Taylor polynomials describing the lens profiles demonstrate excellent imaging performance and the versatility of this new analytic design method. PMID:22418364

  2. 'They can't report abuse, they can't move out. They are at the mercy of these men': exploring connections between intimate partner violence, gender and HIV in South African clinical settings.

    PubMed

    Sprague, Courtenay; Hatcher, Abigail M; Woollett, Nataly; Sommers, Theresa; Black, Vivian

    2016-05-01

    This qualitative study captured South African female health provider perspectives of intimate partner violence in female patients, gender norms and consequences for patients' health. Findings indicated female patients' health behaviours were predicated on sociocultural norms of submission to men's authority and economic dependence on their partners. Respondents described how men's preferences and health decision-making in clinics affected their patients' health. Adverse gender norms and gender inequalities affected women's opportunities to be healthy, contributing to HIV risk and undermining effective HIV management in this context. Some providers, seeking to deliver a standard of quality healthcare to their female patients, demonstrated a willingness to challenge patriarchal gender relations. Findings enhance understanding of how socially-sanctioned gender norms, intimate partner violence and HIV are synergistic, also reaffirming the need for integrated HIV-intimate partner violence responses in multi-sector national strategic plans. Health providers' intimate knowledge of the lived experiences of female patients with intimate partner violence and/or HIV deepens understanding of how adverse gender norms generate health risks for women in ways that may inform policy and clinical practice in South Africa and other high-HIV prevalence settings. PMID:26505136

  3. ‘Peace’ and ‘life worthwhile’ as measures of spiritual well-being in African palliative care: a mixed-methods study

    PubMed Central

    2013-01-01

    Background Patients with incurable, progressive disease receiving palliative care in sub-Saharan Africa experience high levels of spiritual distress with a detrimental impact on their quality of life. Locally validated measurement tools are needed to identify patients’ spiritual needs and evaluate and improve spiritual care, but up to now such tools have been lacking in Africa. The African Palliative Care Association (APCA) African Palliative Outcome Scale (POS) contains two items relating to peace and life worthwhile. We aimed to determine the content and construct validity of these items as measures of spiritual wellbeing in African palliative care populations. Methods The study was conducted at five palliative care services, four in South Africa and one in Uganda. The mixed-methods study design involved: (1) cognitive interviews with 72 patients, analysed thematically to explore the items’ content validity, and (2) quantitative data collection (n = 285 patients) using the POS and the Spirit 8 to assess construct validity. Results (1) Peace was interpreted according to the themes ‘perception of self and world’, ‘relationship to others’, ‘spiritual beliefs’ and ‘health and healthcare’. Life worthwhile was interpreted in relation to ‘perception of self and world’, ‘relationship to others’ and ‘identity’. (2) Conceptual convergence and divergence were also evident in the quantitative data: there was moderate correlation between peace and Spirit 8 spiritual well-being (r = 0.46), but little correlation between life worthwhile and Spirit 8 spiritual well-being (r = 0.18) (both p < 0.001). Correlations with Spirit 8 items were weak to moderate. Conclusions Findings demonstrate the utility of POS items peace and life worthwhile as distinct but related measures of spiritual well-being in African palliative care. Peace and life worthwhile are brief and simple enough to be integrated into routine practice and can be used to

  4. Use of the delta-t method for setting rf phase and amplitude for the AHF linac

    SciTech Connect

    Swain, G.R.

    1989-01-01

    The delta-t procedure is a time-of-flight method of finding set points for the rf phase and amplitude for each module of a linac. Expected errors for LAMPF afterburner linacs which might be used for an advanced hadron facility (AHF) are calculated. The modified delta-t procedure used on modules 13 through 48 of the present linac appears adequate to set up the proposed AHF linacs. 24 refs., 7 figs., 1 tab.

  5. Impact of anthropogenic and climatic changes on biomass and diversity of the Central African forests, from local to global scale: original methods for new results

    NASA Astrophysics Data System (ADS)

    Mortier, Frédéric; Gourlet-Fleury, Sylvie; Ouédraogo, Dakis; Picard, Nicolas; Rossi, Vivien

    2014-05-01

    Forests of the Congo Basin, the second most important remaining block of tropical moist forest in the world, are facing increasing anthropogenic pressure and climate change. Understanding the biomass and diversity dynamics under these pressures is one major challenge for African nations and international communities. This talk aims to present original methods to model, infer, and predict growth, biomass and diversity of Central African forests, as well as new results on the impacts of global change on those forests, at various scales. With respect to methods, we will present theoretical frameworks allowing (i) to model growth processes in species-rich ecosystems like tropical rain forests, (ii) to take into account uncertainties in biomass estimation. In terms of results, we will highlight at a local scale, how human activities as well as climatic variations would impact (i) the composition and diversity of forests, (ii) the dynamics of biomass and growth processes. At a global scale, we will demonstrate how environmental filtering controls the above ground biomass. The number of studies are currently increasing over the Congo Basin through several research projects led by our team (CoForTips, DynAfFor) and contributing to various international organization's programs (Cifor, FAO, Comifac, Ofac).

  6. Sensitivity of the properties of ruthenium ``blue dimer'' to method, basis set, and continuum model

    NASA Astrophysics Data System (ADS)

    Ozkanlar, Abdullah; Clark, Aurora E.

    2012-05-01

    The ruthenium "blue dimer" [(bpy)2RuIIIOH2]2O4+ is best known as the first well-defined molecular catalyst for water oxidation. It has been subject to numerous computational studies primarily employing density functional theory. However, those studies have been limited in the functionals, basis sets, and continuum models employed. The controversy in the calculated electronic structure and the reaction energetics of this catalyst highlights the necessity of benchmark calculations that explore the role of density functionals, basis sets, and continuum models upon the essential features of blue-dimer reactivity. In this paper, we report Kohn-Sham complete basis set (KS-CBS) limit extrapolations of the electronic structure of "blue dimer" using GGA (BPW91 and BP86), hybrid-GGA (B3LYP), and meta-GGA (M06-L) density functionals. The dependence of solvation free energy corrections on the different cavity types (UFF, UA0, UAHF, UAKS, Bondi, and Pauling) within polarizable and conductor-like polarizable continuum model has also been investigated. The most common basis sets of double-zeta quality are shown to yield results close to the KS-CBS limit; however, large variations are observed in the reaction energetics as a function of density functional and continuum cavity model employed.

  7. 48 CFR 19.502-5 - Methods of conducting set-asides.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (see part 13), sealed bids (see part 14), or competitive proposals (see part 15). Partial small business set-asides may be conducted using sealed bids (see part 14), or competitive proposals (see part 15... the size representation, an SBA determination must be obtained (see subpart 19.3)....

  8. Rejoinder: Evaluating Standard Setting Methods Using Error Models Proposed by Schulz

    ERIC Educational Resources Information Center

    Reckase, Mark D.

    2006-01-01

    Schulz (2006) provides a different perspective on standard setting than that provided in Reckase (2006). He also suggests a modification to the bookmark procedure and some alternative models for errors in panelists' judgments than those provided by Reckase. This article provides a response to some of the points made by Schulz and reports some…

  9. Illumination Sufficiency Survey Techniques: In-situ Measurements of Lighting System Performance and a User Preference Survey for Illuminance in an Off-Grid, African Setting

    SciTech Connect

    Alstone, Peter; Jacobson, Arne; Mills, Evan

    2010-08-26

    Efforts to promote rechargeable electric lighting as a replacement for fuel-based light sources in developing countries are typically predicated on the notion that lighting service levels can be maintained or improved while reducing the costs and environmental impacts of existing practices. However, the extremely low incomes of those who depend on fuel-based lighting create a need to balance the hypothetically possible or desirable levels of light with those that are sufficient and affordable. In a pilot study of four night vendors in Kenya, we document a field technique we developed to simultaneously measure the effectiveness of lighting service provided by a lighting system and conduct a survey of lighting service demand by end-users. We took gridded illuminance measurements across each vendor's working and selling area, with users indicating the sufficiency of light at each point. User light sources included a mix of kerosene-fueled hurricane lanterns, pressure lamps, and LED lanterns.We observed illuminance levels ranging from just above zero to 150 lux. The LED systems markedly improved the lighting service levels over those provided by kerosene-fueled hurricane lanterns. Users reported that the minimum acceptable threshold was about 2 lux. The results also indicated that the LED lamps in use by the subjects did not always provide sufficient illumination over the desired retail areas. Our sample size is much too small, however, to reach any conclusions about requirements in the broader population. Given the small number of subjects and very specific type of user, our results should be regarded as indicative rather than conclusive. We recommend replicating the method at larger scales and across a variety of user types and contexts. Policymakers should revisit the subject of recommended illuminance levels regularly as LED technology advances and the price/service balance point evolves.

  10. A comparison of limit setting methods for the on-off problem

    NASA Astrophysics Data System (ADS)

    Rolke, Wolfgang A.

    2016-01-01

    We study the frequentist properties of confidence intervals found with various methods previously proposed for the On-Off problem. We derive explicit formulas for the limits and calculate the true coverage and the expected lengths of these methods.

  11. A variational approach to multi-phase motion of gas, liquid and solid based on the level set method

    NASA Astrophysics Data System (ADS)

    Yokoi, Kensuke

    2009-07-01

    We propose a simple and robust numerical algorithm to deal with multi-phase motion of gas, liquid and solid based on the level set method [S. Osher, J.A. Sethian, Front propagating with curvature-dependent speed: Algorithms based on Hamilton-Jacobi formulation, J. Comput. Phys. 79 (1988) 12; M. Sussman, P. Smereka, S. Osher, A level set approach for capturing solution to incompressible two-phase flow, J. Comput. Phys. 114 (1994) 146; J.A. Sethian, Level Set Methods and Fast Marching Methods, Cambridge University Press, 1999; S. Osher, R. Fedkiw, Level Set Methods and Dynamics Implicit Surface, Applied Mathematical Sciences, vol. 153, Springer, 2003]. In Eulerian framework, to simulate interaction between a moving solid object and an interfacial flow, we need to define at least two functions (level set functions) to distinguish three materials. In such simulations, in general two functions overlap and/or disagree due to numerical errors such as numerical diffusion. In this paper, we resolved the problem using the idea of the active contour model [M. Kass, A. Witkin, D. Terzopoulos, Snakes: active contour models, International Journal of Computer Vision 1 (1988) 321; V. Caselles, R. Kimmel, G. Sapiro, Geodesic active contours, International Journal of Computer Vision 22 (1997) 61; G. Sapiro, Geometric Partial Differential Equations and Image Analysis, Cambridge University Press, 2001; R. Kimmel, Numerical Geometry of Images: Theory, Algorithms, and Applications, Springer-Verlag, 2003] introduced in the field of image processing.

  12. The expanded FindCore method for identification of a core atom set for assessment of protein structure prediction.

    PubMed

    Snyder, David A; Grullon, Jennifer; Huang, Yuanpeng J; Tejero, Roberto; Montelione, Gaetano T

    2014-02-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (Snyder and Montelione, Proteins 2005;59:673-686) is a superimposition independent method for identifying a core atom set and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an "Expanded FindCore" atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines "expanded core atom sets" that match an expert's intuition of which parts of the structure are sufficiently well defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  13. Patient goal setting as a method for program improvement/development in partial hospitalization programs.

    PubMed

    Gates, A

    1991-12-01

    Data were collected from a study of 49 patients in 1990 and 106 patients in 1991 admitted into Country View Treatment Center and Green Country Counseling Center. Country View is a 30-bed chemical dependency residential center operating under St. John Medical Center in Tulsa, Oklahoma. Green Country is an evening partial hospital chemical dependency program operating under St. John Medical Center in Tulsa, Oklahoma, The tools used in this study were the Country View Patient Self-Reporting Questionnaire, the global Rating Scale, and the Model of Recovering Alcoholics Behavior Stages and Goal Setting (Wing, 1990). These assessments were specifically designed to measure the patient's perceptions of goal setting and the patient's perspective on treatment outcome. The study outcome resulted in program improvement (Green Country evening partial hospital program) and the development of the Country View Substance Abuse Intermediate Link (SAIL) Program (day partial hospital). PMID:10170967

  14. Difficulties Experienced in Setting and Achieving Goals by Participants of a Falls Prevention Programme: A Mixed-Methods Evaluation

    PubMed Central

    Mason, Wendy; Haines, Terry P.

    2014-01-01

    ABSTRACT Purpose: To evaluate the ability of participants of a falls prevention programme to set and achieve goals. Methods: The study used a prospective longitudinal design and a mixed-methods approach to data collection. Study participants were (1) 220 older adults participating in a 15-week combined exercise and education falls prevention programme and (2) 9 practitioners (3 home-care nurses, 5 community workers, and an exercise physiologist) involved in delivering the programme. Data from goal-setting forms were analyzed, and descriptive statistics were used to determine the number of appropriate goals set and achieved. Data were analyzed according to programme setting (home- or group-based) and whether or not participants were classified as being from a Culturally and Linguistically Diverse (CALD) background in the Australian context. Semi-structured interviews with programme practitioners were thematically analyzed. Results: A total of 144 respondents (n=75 CALD group, n=41 non-CALD group, n=6 CALD home, n=22 non-CALD home) set 178 goals. Only 101 (57%) goals could be evaluated according to achievement, because participants set goals that focused on health state instead of behaviour, set goals not relevant to falls prevention, used inappropriate constructs to measure goal achievement, and either did not review their goals or dropped out of the programme before goal review. Of these 101 goals, 64 were achieved. Practitioners described their own difficulties in understanding the process of setting health behaviour goals along with communication, cultural, and logistic difficulties. Conclusions: Both CALD and non-CALD participants and those participating in both group- and home-based programmes experienced difficulty in setting and achieving goals to facilitate behaviour change for falls prevention. Data suggest that home-based participants had more difficulty in setting goals than their group-based counterparts and, to a lesser extent, that CALD participants

  15. It Takes a Village: A Mixed Method Analysis of Inner Setting Variables and Dialectical Behavior Therapy Implementation.

    PubMed

    Ditty, Matthew S; Landes, Sara J; Doyle, Andrea; Beidas, Rinad S

    2015-11-01

    Guided by the Consolidated Framework for Implementation Research, this mixed method study explored the relationship between inner setting variables and dialectical behavior therapy (DBT) implementation. Intensively trained DBT clinicians completed an online quantitative survey (n = 79) and a subset were sequentially interviewed using qualitative methods (n = 20) to identify relationships between inner setting variables and DBT implementation. Four interpersonal variables-team cohesion, team communication, team climate, and supervision-were correlated with the quantity of DBT elements implemented. Qualitative themes corroborated these findings. Additional variables were connected to implementation by either quantitative or qualitative findings, but not both. PMID:25315183

  16. Learning and applying new quality improvement methods to the school health setting.

    PubMed

    Elik, Laurel L

    2013-11-01

    A school health registered nurse identified medication administration documentation errors by unlicensed assistive personnel (UAP) in a system of school health clinics in an urban setting. This nurse applied the Lean Six Sigma Define, Measure, Analyze, Improve, Control process of improvement methodology to effectively improve the process. The UAP of medication administration documentation error rate improved from 68% to 35%. This methodology may be used by school nurses to collaboratively look at ways to improve processes at the point of care. PMID:24386696

  17. Simulation of Heterogeneous Atom Probe Tip Shapes Evolution during Field Evaporation Using a Level Set Method and Different Evaporation Models

    SciTech Connect

    Xu, Zhijie; Li, Dongsheng; Xu, Wei; Devaraj, Arun; Colby, Robert J.; Thevuthasan, Suntharampillai; Geiser, B. P.; Larson, David J.

    2015-04-01

    In atom probe tomography (APT), accurate reconstruction of the spatial positions of field evaporated ions from measured detector patterns depends upon a correct understanding of the dynamic tip shape evolution and evaporation laws of component atoms. Artifacts in APT reconstructions of heterogeneous materials can be attributed to the assumption of homogeneous evaporation of all the elements in the material in addition to the assumption of a steady state hemispherical dynamic tip shape evolution. A level set method based specimen shape evolution model is developed in this study to simulate the evaporation of synthetic layered-structured APT tips. The simulation results of the shape evolution by the level set model qualitatively agree with the finite element method and the literature data using the finite difference method. The asymmetric evolving shape predicted by the level set model demonstrates the complex evaporation behavior of heterogeneous tip and the interface curvature can potentially lead to the artifacts in the APT reconstruction of such materials. Compared with other APT simulation methods, the new method provides smoother interface representation with the aid of the intrinsic sub-grid accuracy. Two evaporation models (linear and exponential evaporation laws) are implemented in the level set simulations and the effect of evaporation laws on the tip shape evolution is also presented.

  18. LEGO: a novel method for gene set over-representation analysis by incorporating network-based gene weights.

    PubMed

    Dong, Xinran; Hao, Yun; Wang, Xiao; Tian, Weidong

    2016-01-01

    Pathway or gene set over-representation analysis (ORA) has become a routine task in functional genomics studies. However, currently widely used ORA tools employ statistical methods such as Fisher's exact test that reduce a pathway into a list of genes, ignoring the constitutive functional non-equivalent roles of genes and the complex gene-gene interactions. Here, we develop a novel method named LEGO (functional Link Enrichment of Gene Ontology or gene sets) that takes into consideration these two types of information by incorporating network-based gene weights in ORA analysis. In three benchmarks, LEGO achieves better performance than Fisher and three other network-based methods. To further evaluate LEGO's usefulness, we compare LEGO with five gene expression-based and three pathway topology-based methods using a benchmark of 34 disease gene expression datasets compiled by a recent publication, and show that LEGO is among the top-ranked methods in terms of both sensitivity and prioritization for detecting target KEGG pathways. In addition, we develop a cluster-and-filter approach to reduce the redundancy among the enriched gene sets, making the results more interpretable to biologists. Finally, we apply LEGO to two lists of autism genes, and identify relevant gene sets to autism that could not be found by Fisher. PMID:26750448

  19. LEGO: a novel method for gene set over-representation analysis by incorporating network-based gene weights

    PubMed Central

    Dong, Xinran; Hao, Yun; Wang, Xiao; Tian, Weidong

    2016-01-01

    Pathway or gene set over-representation analysis (ORA) has become a routine task in functional genomics studies. However, currently widely used ORA tools employ statistical methods such as Fisher’s exact test that reduce a pathway into a list of genes, ignoring the constitutive functional non-equivalent roles of genes and the complex gene-gene interactions. Here, we develop a novel method named LEGO (functional Link Enrichment of Gene Ontology or gene sets) that takes into consideration these two types of information by incorporating network-based gene weights in ORA analysis. In three benchmarks, LEGO achieves better performance than Fisher and three other network-based methods. To further evaluate LEGO’s usefulness, we compare LEGO with five gene expression-based and three pathway topology-based methods using a benchmark of 34 disease gene expression datasets compiled by a recent publication, and show that LEGO is among the top-ranked methods in terms of both sensitivity and prioritization for detecting target KEGG pathways. In addition, we develop a cluster-and-filter approach to reduce the redundancy among the enriched gene sets, making the results more interpretable to biologists. Finally, we apply LEGO to two lists of autism genes, and identify relevant gene sets to autism that could not be found by Fisher. PMID:26750448

  20. Comparing Methods of Racial and Ethnic Disparities Measurement across Different Settings of Mental Health Care

    PubMed Central

    Lê Cook, Benjamin; McGuire, Thomas G; Lock, Kari; Zaslavsky, Alan M

    2010-01-01

    Introduction The ability to track improvement against racial/ethnic disparities in mental health care is hindered by the varying methods and disparity definitions used in previous research. Data Nationally representative sample of whites, blacks, and Latinos from the 2002 to 2006 Medical Expenditure Panel Survey. Dependent variables are total, outpatient, and prescription drug mental health care expenditure. Methods Rank- and propensity score-based methods concordant with the Institute of Medicine (IOM) definition of health care disparities were compared with commonly used disparities methods. To implement the IOM definition, we modeled expenditures using a two-part GLM, adjusted distributions of need variables, and predicted expenditures for each racial/ethnic group. Findings Racial/ethnic disparities were significant for all expenditure measures. Disparity estimates from the IOM-concordant methods were similar to one another but greater than a method using the residual effect of race/ethnicity. Black–white and Latino–white disparities were found for any expenditure in each category and Latino–white disparities were significant in expenditure conditional on use. Conclusions Findings of disparities in access among blacks and disparities in access and expenditures after initiation among Latinos suggest the need for continued policy efforts targeting disparities reduction. In these data, the propensity score-based method and the rank-and-replace method were precise and adequate methods of implementing the IOM definition of disparity. PMID:20337739

  1. A Conceptual Framework for a Psychometric Theory for Standard Setting with Examples of Its Use for Evaluating the Functioning of Two Standard Setting Methods

    ERIC Educational Resources Information Center

    Reckase, Mark D.

    2006-01-01

    A conceptual framework is proposed for a psychometric theory of standard setting. The framework suggests that participants in a standard setting process (panelists) develop an internal, intended standard as a result of training and the participant's background. The goal of a standard setting process is to convert panelists' intended standards to…

  2. Effects of the method of apatite seed crystals addition on setting reaction of α-tricalcium phosphate based apatite cement.

    PubMed

    Tsuru, Kanji; Ruslin; Maruta, Michito; Matsuya, Shigeki; Ishikawa, Kunio

    2015-10-01

    Appropriate setting time is an important parameter that determines the effectiveness of apatite cement (AC) for clinical application, given the issues of crystalline inflammatory response phenomena if AC fails to set. To this end, the present study analyzes the effects of the method of apatite seed crystals addition on the setting reaction of α-tricalcium phosphate (α-TCP) based AC. Two ACs, both consisting of α-TCP and calcium deficient hydroxyapatite (cdHAp), were analyzed in this study. In one AC, cdHAp was added externally to α-TCP and this AC was abbreviated as AC(EA). In the other AC, α-TCP was partially hydrolyzed to form cdHAp on the surface of α-TCP. This AC was referred to as AC(PH). Results indicate a decrease in the setting time of both ACs with the addition of cdHAp. Among them, for the given amount of added cdHAp, AC(PH) showed relatively shorter setting time than AC(EA). Besides, the mechanical strength of the set AC(PH) was also higher than that of set AC(EA). These properties of AC(PH) were attributed to the predominant crystal growth of cdHAp in the vicinity of the α-TCP particle surface. Accordingly, it can be concluded that the partial hydrolysis of α-TCP may be a better approach to add low crystalline cdHAp onto α-TCP based AC. PMID:26411440

  3. Standardized method to quantify the variation in voxel value distribution in patient-simulated CBCT data sets

    PubMed Central

    Gotfredsen, E; Wenzel, A

    2015-01-01

    Objectives: To suggest a standardized method to assess the variation in voxel value distribution in patient-simulated CBCT data sets and the effect of time between exposures (TBE). Additionally, a measurement of reproducibility, Aarhus measurement of reproducibility (AMORe), is introduced, which could be used for quality assurance purposes. Methods: Six CBCT units were tested [Cranex® 3D/CRAN (Soredex Oy, Tuusula, Finland); Scanora® 3D/SCAN (Soredex Oy); NewTom™ 5G/NEW5 (QR srl, Verona, Italy); i-CAT/ICAT (Imaging Sciences International, Hatfield, PA); 3D Accuitomo FPD80/ACCU (Morita, Kyoto, Japan); and NewTom VG/NEWV (QR srl)]. Two sets of volumetric data of a wax-imbedded dry human skull (containing a titanium implant) were acquired by each CBCT unit at two sessions on separate days. Each session consisted 21 exposures: 1 “initial” followed by a 30-min interval (initial data set), 10 acquired with 30-min TBE (data sets 1–10) and 10 acquired with 15-min TBE (data sets 11–20). CBCT data were exported as digital imaging and communications in medicine files and converted to text files containing x, y and z positions and grey shade for each voxel. Subtractions were performed voxel-by-voxel in two set-ups: (1) between two consecutive data sets and (2) between any subsequent data set and data set 1. The mean grey shade variation for each voxel was calculated for each unit/session. Results: The largest mean grey shade variation was found in the subtraction set-up 2 (27–447 shades of grey, depending on the unit). Considering subtraction set-up 1, the highest variation was seen for NEW5, between data sets 1 and the initial. Conclusions: Discrepancies in voxel value distribution were found by comparing the initial examination of the day with the subsequent examinations. TBE had no predictable effect on the variation of CBCT-derived voxel values. AMORe ranged between 0 and 64. PMID:25354021

  4. How to select basis sets and computational methods for carbohydrate modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the last decade there have been significant improvements in computer hardware but also in development of quantum mechanical methods. This makes it more feasible to study large carbohydrate molecules via quantum mechanical methods whereas in the past studies of carbohydrates were restricted to em...

  5. Ab initio modeling of carbohydrates: on the proper selection of computational methods and basis sets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the development of faster computer hardware and quantum mechanical software it has become more feasible to study large carbohydrate molecules via quantum mechanical methods. In the past, studies of carbohydrates were restricted to empirical/semiempirical methods and Hartree Fock. In the last ...

  6. The Television Framing Methods of the National Basketball Association: An Agenda-Setting Application.

    ERIC Educational Resources Information Center

    Fortunato, John A.

    2001-01-01

    Identifies and analyzes the exposure and portrayal framing methods that are utilized by the National Basketball Association (NBA). Notes that key informant interviews provide insight into the exposure framing method and reveal two portrayal instruments: cameras and announcers; and three framing strategies: depicting the NBA as a team game,…

  7. Obesity and African Americans

    MedlinePlus

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  8. The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

    PubMed Central

    Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

    2014-01-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identifying a core atom set, and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an “Expanded FindCore” atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines “expanded core atom sets” that match an expert’s intuition of which parts of the structure are sufficiently well-defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  9. A Method Defining a Limited Set of Character-Strings with Maximal Coverage of a Sample of Text.

    ERIC Educational Resources Information Center

    Hultgren, Jan; Larsson, Rolf

    This is a progress report on a project attempting to design a system of compacting text for storage appropriate to disc oriented demand searching. After noting a number of previously designed methods of compression, it offers a tentative solution which couples a dictionary of most frequent character-strings with a set of variable-length codes. The…

  10. 10 CFR Appendix H to Subpart B of... - Uniform Test Method for Measuring the Power Consumption of Television Sets

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Uniform Test Method for Measuring the Power Consumption of Television Sets H Appendix H to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY... 23, 2014, any representations made with respect to the energy use or efficiency of televisions...

  11. 'Gene shaving' as a method for identifying distinct sets of genes with similar expression patterns

    PubMed Central

    Hastie, Trevor; Tibshirani, Robert; Eisen, Michael B; Alizadeh, Ash; Levy, Ronald; Staudt, Louis; Chan, Wing C; Botstein, David; Brown, Patrick

    2000-01-01

    Background: Large gene expression studies, such as those conducted using DNA arrays, often provide millions of different pieces of data. To address the problem of analyzing such data, we describe a statistical method, which we have called 'gene shaving'. The method identifies subsets of genes with coherent expression patterns and large variation across conditions. Gene shaving differs from hierarchical clustering and other widely used methods for analyzing gene expression studies in that genes may belong to more than one cluster, and the clustering may be supervised by an outcome measure. The technique can be 'unsupervised', that is, the genes and samples are treated as unlabeled, or partially or fully supervised by using known properties of the genes or samples to assist in finding meaningful groupings. Results: We illustrate the use of the gene shaving method to analyze gene expression measurements made on samples from patients with diffuse large B-cell lymphoma. The method identifies a small cluster of genes whose expression is highly predictive of survival. Conclusions: The gene shaving method is a potentially useful tool for exploration of gene expression data and identification of interesting clusters of genes worth further investigation. PMID:11178228

  12. Two Methods for Engaging with the Community in Setting Priorities for Child Health Research: Who Engages?

    PubMed Central

    McKenzie, Anne; Hancock, Kirsten; Haines, Hayley; Christensen, Daniel; Zubrick, Stephen R.

    2015-01-01

    Objective The aims of this study were to assess participatory methods for obtaining community views on child health research. Background Community participation in research is recognised as an important part of the research process; however, there has been inconsistency in its implementation and application in Australia. The Western Australian Telethon Kids Institute Participation Program employs a range of methods for fostering active involvement of community members in its research. These include public discussion forums, called Community Conversations. While participation levels are good, the attendees represent only a sub-section of the Western Australian population. Therefore, we conducted a telephone survey of randomly selected households to evaluate its effectiveness in eliciting views from a broader cross-section of the community about our research agenda and community participation in research, and whether the participants would be representative of the general population. We also conducted two Conversations, comparing the survey as a recruitment tool and normal methods using the Participation Program. Results While the telephone survey was a good method for eliciting community views about research, there were marked differences in the profile of study participants compared to the general population (e.g. 78% vs 50% females). With a 26% response rate, the telephone survey was also more expensive than a Community Conversation. The cold calling approach proved an unsuccessful recruitment method, with only two out of a possible 816 telephone respondents attending a Conversation. Conclusion While the results showed that both of the methods produced useful input for our research program, we could not conclude that either method gained input that was representative of the entire community. The Conversations were relatively low-cost and provided more in-depth information about one subject, whereas the telephone survey provided information across a greater range

  13. Comparison of methods to identify significant proteinuria in pregnancy in the outpatient setting.

    PubMed

    Kyle, P M; Fielder, J N; Pullar, B; Horwood, L J; Moore, M P

    2008-03-01

    The efficacy of the albumin/creatinine ratio (ACR) measurement in detection of significant proteinuria when performed in a high-risk antenatal clinic was compared with automated dipstick, protein/creatinine ratio (PCR), and 24-hour urine protein measurements. Both the ACR (DCA 2000) and PCR were strongly predictive for the presence or absence of significant proteinuria, with positive likelihood ratios (LRs) of 27.4 and 31.6 and negative LRs of 0.0 and 0.1, respectively. Both the ACR (DCA 2000) and PCR are effective tests for both identifying and excluding significant proteinuria in the outpatient setting. The ACR (DCA 2000) has the advantage of providing an immediate result. PMID:18201282

  14. Electromagnetic sunscreen model: implementation and comparison between several methods: step-film model, differential method, Mie scattering, and scattering by a set of parallel cylinders.

    PubMed

    Lécureux, Marie; Enoch, Stefan; Deumié, Carole; Tayeb, Gérard

    2014-10-01

    Sunscreens protect from UV radiation, a carcinogen also responsible for sunburns and age-associated dryness. In order to anticipate the transmission of light through UV protection containing scattering particles, we implement electromagnetic models, using numerical methods for solving Maxwell's equations. After having our models validated, we compare several calculation methods: differential method, scattering by a set of parallel cylinders, or Mie scattering. The field of application and benefits of each method are studied and examples using the appropriate method are described. PMID:25322243

  15. Combining evidence and values in priority setting: testing the balance sheet method in a low-income country

    PubMed Central

    Makundi, Emmanuel; Kapiriri, Lydia; Norheim, Ole Frithjof

    2007-01-01

    Background Procedures for priority setting need to incorporate both scientific evidence and public values. The aim of this study was to test out a model for priority setting which incorporates both scientific evidence and public values, and to explore use of evidence by a selection of stakeholders and to study reasons for the relative ranking of health care interventions in a setting of extreme resource scarcity. Methods Systematic search for and assessment of relevant evidence for priority setting in a low-income country. Development of a balance sheet according to Eddy's explicit method. Eight group interviews (n-85), using a modified nominal group technique for eliciting individual and group rankings of a given set of health interventions. Results The study procedure made it possible to compare the groups' ranking before and after all the evidence was provided to participants. A rank deviation is significant if the rank order of the same intervention differed by two or more points on the ordinal scale. A comparison between the initial rank and the final rank (before deliberation) showed a rank deviation of 67%. The difference between the initial rank and the final rank after discussion and voting gave a rank deviation of 78%. Conclusion Evidence-based and deliberative decision-making does change priorities significantly in an experimental setting. Our use of the balance sheet method was meant as a demonstration project, but could if properly developed be feasible for health planners, experts and health workers, although more work is needed before it can be used for laypersons. PMID:17892561

  16. A comparative evaluation of PCR- based methods for species- specific determination of African animal trypanosomes in Ugandan cattle

    PubMed Central

    2013-01-01

    Background In recent years, PCR has been become widely applied for the detection of trypanosomes overcoming many of the constraints of parasitological and serological techniques, being highly sensitive and specific for trypanosome detection. Individual species-specific multi-copy trypanosome DNA sequences can be targeted to identify parasites. Highly conserved ribosomal RNA (rRNA) genes are also useful for comparisons between closely related species. The internal transcribed spacer regions (ITS) in particular are relatively small, show variability among related species and are flanked by highly conserved segments to which PCR primers can be designed. Individual variations in inter-species length makes the ITS region a useful marker for identification of multiple trypanosome species within a sample. Methods Six hundred blood samples from cattle collected in Uganda on FTA cards were screened using individual species-specific primers for Trypanosoma congolense, Trypanosoma brucei and Trypanosoma vivax and compared to a modified (using eluate extracted using chelex) ITS-PCR reaction. Results The comparative analysis showed that the species-specific primer sets showed poor agreement with the ITS primer set. Using species-specific PCR for Trypanozoon, a prevalence of 10.5% was observed as compared to 0.2% using ITS PCR (Kappa = 0.03). For Trypanosoma congolense, the species-specific PCR reaction indicated a prevalence of 0% compared to 2.2% using ITS PCR (Kappa = 0). For T. vivax, species-specific PCR detected prevalence of 5.7% compared to 2.8% for ITS PCR (Kappa = 0.29). Conclusions When selecting PCR based tools to apply to epidemiological surveys for generation of prevalence data for animal trypanosomiasis, it is recommended that species-specific primers are used, being the most sensitive diagnostic tool for screening samples to identify members of Trypanozoon (T. b. brucei s.l). While ITS primers are useful for studying the prevalence of trypanosomes

  17. Evaluating the ability of Bayesian clustering methods to detect hybridization and introgression using an empirical red wolf data set.

    PubMed

    Bohling, Justin H; Adams, Jennifer R; Waits, Lisette P

    2013-01-01

    Bayesian clustering methods have emerged as a popular tool for assessing hybridization using genetic markers. Simulation studies have shown these methods perform well under certain conditions; however, these methods have not been evaluated using empirical data sets with individuals of known ancestry. We evaluated the performance of two clustering programs, baps and structure, with genetic data from a reintroduced red wolf (Canis rufus) population in North Carolina, USA. Red wolves hybridize with coyotes (C. latrans), and a single hybridization event resulted in introgression of coyote genes into the red wolf population. A detailed pedigree has been reconstructed for the wild red wolf population that includes individuals of 50-100% red wolf ancestry, providing an ideal case study for evaluating the ability of these methods to estimate admixture. Using 17 microsatellite loci, we tested the programs using different training set compositions and varying numbers of loci. structure was more likely than baps to detect an admixed genotype and correctly estimate an individual's true ancestry composition. However, structure was more likely to misclassify a pure individual as a hybrid. Both programs were outperformed by a maximum-likelihood-based test designed specifically for this system, which never misclassified a hybrid (50-75% red wolf) as a red wolf or vice versa. Training set composition and the number of loci both had an impact on accuracy but their relative importance varied depending on the program. Our findings demonstrate the importance of evaluating methods used for detecting admixture in the context of endangered species management. PMID:23163531

  18. Parallel, linear-scaling building-block and embedding method based on localized orbitals and orbital-specific basis sets.

    PubMed

    Seijo, Luis; Barandiarán, Zoila

    2004-10-01

    We present a linear scaling method for the energy minimization step of semiempirical and first-principles Hartree-Fock and Kohn-Sham calculations. It is based on the self-consistent calculation of the optimum localized orbitals of any localization method of choice and on the use of orbital-specific basis sets. The full set of localized orbitals of a large molecule is seen as an orbital mosaic where each tessera is made of only a few of them. The orbital tesserae are computed out of a set of embedded cluster pseudoeigenvalue coupled equations which are solved in a building-block self-consistent fashion. In each iteration, the embedded cluster equations are solved independently of each other and, as a result, the method is parallel at a high level of the calculation. In addition to full system calculations, the method enables to perform simpler, much less demanding embedded cluster calculations, where only a fraction of the localized molecular orbitals are variational while the rest is frozen, taking advantage of the transferability of the localized orbitals of a given localization method between similar molecules. Monitoring single point energy calculations of large poly(ethylene oxide) molecules and three dimensional carbon monoxide clusters using an extended Huckel Hamiltonian are presented. PMID:15473725

  19. Evaluation of Accuracy and Reliability of the Six Ensemble Methods Using 198 Sets of Pseudo-Simulation Data

    NASA Astrophysics Data System (ADS)

    Suh, M. S.; Oh, S. G.

    2014-12-01

    The accuracy and reliability of the six ensemble methods were evaluated according to simulation skills, training period, and ensemble members, using 198 sets of pseudo-simulation data (PSD) generated by considering the simulation characteristics of regional climate models. The PSD sets were classified into 18 categories according to the relative magnitude of bias, variance ratio, and correlation coefficient, where each category had 11 sets with 50 samples. The ensemble methods used were as follows: equal weighted averaging with(out) bias correction (EWA_W(N)BC), weighted ensemble averaging based on root mean square errors and correlation (WEA_RAC), WEA based on the Taylor score (WEA_Tay), WEA based on reliability (WEA_REA), and multivariate linear regression (Mul_Reg). The weighted ensemble methods showed better projection skills in terms of accuracy and reliability than non-weighted methods, in particular, for the PSD categories having systematic biases and various correlation coefficients. In general, WEA_Tay, WEA_REA and WEA_RAC showed superior skills in terms of accuracy and reliability, regardless of the PSD categories, training periods, and ensemble numbers. The evaluation results showed that WEA_Tay and WEA_RAC are applicable even for simulation data with systematic biases, a short training period, and a small number of members. However, the EWA_NBC showed a comparable projection skill with the other methods only in the certain categories with unsystematic biases.

  20. Method for detecting the signature of noise-induced structures in spatiotemporal data sets: an application to excitable media

    NASA Astrophysics Data System (ADS)

    Huett, Marc-Thorsten

    2003-05-01

    We formulate mathematical tools for analyzing spatiotemporal data sets. The tools are based on nearest-neighbor considerations similar to cellular automata. One of the analysis tools allows for reconstructing the noise intensity in a data set and is an appropriate method for detecting a variety of noise-induced phenomena in spatiotemporal data. The functioning of these methods is illustrated on sample data generated with the forest fire model and with networks of nonlinear oscillators. It is seen that these methods allow the characterization of spatiotemporal stochastic resonance (STSR) in experimental data. Application of these tools to biological spatiotemporal patterns is discussed. For one specific example, the slime mold Dictyostelium discoideum, it is seen, how transitions between different patterns are clearly marked by changes in the spatiotemporal observables.

  1. Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions

    NASA Astrophysics Data System (ADS)

    Nikolaev, A. V.; Lamoen, D.; Partoens, B.

    2016-07-01

    In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the u ˙ l -component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets.

  2. Researching the Induction of Intending Elementary Science Teachers in Multicultural Settings: The Science Methods Component.

    ERIC Educational Resources Information Center

    McGinnis, J. Randy; Davis, Rachel T.

    This in-depth case study investigated the deliberate attempt to infuse a multicultural perspective throughout a science methods course required of all intending elementary teachers at a major research university. Intending teachers' perspectives of being inducted into a profession overtly signifying its commitment to multicultural awareness and…

  3. Impact of Learning Theory Methods on Undergraduate Retention and Application of Software in a Studio Setting

    ERIC Educational Resources Information Center

    Gomboc-Turyan, Julie L.

    2012-01-01

    The transition from an academic atmosphere to the professional world is an important step in a college student's life. The use of traditional teaching methods has been the subject of ongoing research into how well they prepare students for this transition. The evolution of technology and the state of the nation's economy continually…

  4. Robust, cross-laboratory validated PCR methods to track antibiotic resistance in agricultural settings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to make informed decisions on how best to manage agricultural antibiotics, we need to be able to track and quantify the antibiotic resistant bacteria, and antibiotic resistance genes. PCR-based methods are widely used to both detect and quantify antibiotic resistance genes, however there ar...

  5. Teaching to Think: Applying the Socratic Method outside the Law School Setting

    ERIC Educational Resources Information Center

    Peterson, Evan

    2009-01-01

    An active learning process has the potential to provide educational benefits above-and-beyond what they might receive from more traditional, passive approaches. The Socratic Method is a unique approach to passive learning that facilitates critical thinking, open-mindedness, and teamwork. By imposing a series of guided questions to students, an…

  6. Peptide dynamics by molecular dynamics simulation and diffusion theory method with improved basis sets

    NASA Astrophysics Data System (ADS)

    Hsu, Po Jen; Lai, S. K.; Rapallo, Arnaldo

    2014-03-01

    Improved basis sets for the study of polymer dynamics by means of the diffusion theory, and tests on a melt of cis-1,4-polyisoprene decamers, and a toluene solution of a 71-mer syndiotactic trans-1,2-polypentadiene were presented recently [R. Gaspari and A. Rapallo, J. Chem. Phys. 128, 244109 (2008)]. The proposed hybrid basis approach (HBA) combined two techniques, the long time sorting procedure and the maximum correlation approximation. The HBA takes advantage of the strength of these two techniques, and its basis sets proved to be very effective and computationally convenient in describing both local and global dynamics in cases of flexible synthetic polymers where the repeating unit is a unique type of monomer. The question then arises if the same efficacy continues when the HBA is applied to polymers of different monomers, variable local stiffness along the chain and with longer persistence length, which have different local and global dynamical properties against the above-mentioned systems. Important examples of this kind of molecular chains are the proteins, so that a fragment of the protein transthyretin is chosen as the system of the present study. This peptide corresponds to a sequence that is structured in β-sheets of the protein and is located on the surface of the channel with thyroxin. The protein transthyretin forms amyloid fibrils in vivo, whereas the peptide fragment has been shown [C. P. Jaroniec, C. E. MacPhee, N. S. Astrof, C. M. Dobson, and R. G. Griffin, Proc. Natl. Acad. Sci. U.S.A. 99, 16748 (2002)] to form amyloid fibrils in vitro in extended β-sheet conformations. For these reasons the latter is given considerable attention in the literature and studied also as an isolated fragment in water solution where both experimental and theoretical efforts have indicated the propensity of the system to form β turns or α helices, but is otherwise predominantly unstructured. Differing from previous computational studies that employed implicit

  7. Peptide dynamics by molecular dynamics simulation and diffusion theory method with improved basis sets.

    PubMed

    Hsu, Po Jen; Lai, S K; Rapallo, Arnaldo

    2014-03-14

    Improved basis sets for the study of polymer dynamics by means of the diffusion theory, and tests on a melt of cis-1,4-polyisoprene decamers, and a toluene solution of a 71-mer syndiotactic trans-1,2-polypentadiene were presented recently [R. Gaspari and A. Rapallo, J. Chem. Phys. 128, 244109 (2008)]. The proposed hybrid basis approach (HBA) combined two techniques, the long time sorting procedure and the maximum correlation approximation. The HBA takes advantage of the strength of these two techniques, and its basis sets proved to be very effective and computationally convenient in describing both local and global dynamics in cases of flexible synthetic polymers where the repeating unit is a unique type of monomer. The question then arises if the same efficacy continues when the HBA is applied to polymers of different monomers, variable local stiffness along the chain and with longer persistence length, which have different local and global dynamical properties against the above-mentioned systems. Important examples of this kind of molecular chains are the proteins, so that a fragment of the protein transthyretin is chosen as the system of the present study. This peptide corresponds to a sequence that is structured in β-sheets of the protein and is located on the surface of the channel with thyroxin. The protein transthyretin forms amyloid fibrils in vivo, whereas the peptide fragment has been shown [C. P. Jaroniec, C. E. MacPhee, N. S. Astrof, C. M. Dobson, and R. G. Griffin, Proc. Natl. Acad. Sci. U.S.A. 99, 16748 (2002)] to form amyloid fibrils in vitro in extended β-sheet conformations. For these reasons the latter is given considerable attention in the literature and studied also as an isolated fragment in water solution where both experimental and theoretical efforts have indicated the propensity of the system to form β turns or α helices, but is otherwise predominantly unstructured. Differing from previous computational studies that employed implicit

  8. Peptide dynamics by molecular dynamics simulation and diffusion theory method with improved basis sets

    SciTech Connect

    Hsu, Po Jen; Lai, S. K.; Rapallo, Arnaldo

    2014-03-14

    Improved basis sets for the study of polymer dynamics by means of the diffusion theory, and tests on a melt of cis-1,4-polyisoprene decamers, and a toluene solution of a 71-mer syndiotactic trans-1,2-polypentadiene were presented recently [R. Gaspari and A. Rapallo, J. Chem. Phys. 128, 244109 (2008)]. The proposed hybrid basis approach (HBA) combined two techniques, the long time sorting procedure and the maximum correlation approximation. The HBA takes advantage of the strength of these two techniques, and its basis sets proved to be very effective and computationally convenient in describing both local and global dynamics in cases of flexible synthetic polymers where the repeating unit is a unique type of monomer. The question then arises if the same efficacy continues when the HBA is applied to polymers of different monomers, variable local stiffness along the chain and with longer persistence length, which have different local and global dynamical properties against the above-mentioned systems. Important examples of this kind of molecular chains are the proteins, so that a fragment of the protein transthyretin is chosen as the system of the present study. This peptide corresponds to a sequence that is structured in β-sheets of the protein and is located on the surface of the channel with thyroxin. The protein transthyretin forms amyloid fibrils in vivo, whereas the peptide fragment has been shown [C. P. Jaroniec, C. E. MacPhee, N. S. Astrof, C. M. Dobson, and R. G. Griffin, Proc. Natl. Acad. Sci. U.S.A. 99, 16748 (2002)] to form amyloid fibrils in vitro in extended β-sheet conformations. For these reasons the latter is given considerable attention in the literature and studied also as an isolated fragment in water solution where both experimental and theoretical efforts have indicated the propensity of the system to form β turns or α helices, but is otherwise predominantly unstructured. Differing from previous computational studies that employed implicit

  9. An optical flow based method for improved reconstruction of 4D CT data sets acquired during free breathing

    SciTech Connect

    Ehrhardt, Jan; Werner, Rene; Saering, Dennis; Frenzel, Thorsten; Lu Wei; Low, Daniel; Handels, Heinz

    2007-02-15

    Respiratory motion degrades anatomic position reproducibility and leads to issues affecting image acquisition, treatment planning, and radiation delivery. Four-dimensional (4D) computer tomography (CT) image acquisition can be used to measure the impact of organ motion and to explicitly account for respiratory motion during treatment planning and radiation delivery. Modern CT scanners can only scan a limited region of the body simultaneously and patients have to be scanned in segments consisting of multiple slices. A respiratory signal (spirometer signal or surface tracking) is used to reconstruct a 4D data set by sorting the CT scans according to the couch position and signal coherence with predefined respiratory phases. But artifacts can occur if there are no acquired data segments for exactly the same respiratory state for all couch positions. These artifacts are caused by device-dependent limitations of gantry rotation, image reconstruction times and by the variability of the patient's respiratory pattern. In this paper an optical flow based method for improved reconstruction of 4D CT data sets from multislice CT scans is presented. The optical flow between scans at neighboring respiratory states is estimated by a non-linear registration method. The calculated velocity field is then used to reconstruct a 4D CT data set by interpolating data at exactly the predefined respiratory phase. Our reconstruction method is compared with the usually used reconstruction based on amplitude sorting. The procedures described were applied to reconstruct 4D CT data sets for four cancer patients and a qualitative and quantitative evaluation of the optical flow based reconstruction method was performed. Evaluation results show a relevant reduction of reconstruction artifacts by our technique. The reconstructed 4D data sets were used to quantify organ displacements and to visualize the abdominothoracic organ motion.

  10. Developing a Cancer Prevention Programme for African-American Daughters and Mothers

    ERIC Educational Resources Information Center

    Annang, Lucy; Spencer, S. Melinda; Jackson, Dawnyéa; Rosemond, Tiara N.; Best, Alicia L.; Williams, Leah R.; Carlos, Bethany

    2015-01-01

    Objective: To describe how nominal group technique was used to inform the development of a breast and cervical cancer awareness programme for African-American adult daughters and mothers. Design: A qualitative approach using nominal group technique. Setting: A mid-sized city in the Southern USA. Method: Nominal group technique was used with 30…

  11. Toddler Feeding: Expectations and Experiences of Low-Income African American Mothers

    ERIC Educational Resources Information Center

    Horodynski, Mildred A.; Brophy-Herb, Holly; Henry, Michelle; Smith, Katharine A.; Weatherspoon, Lorraine

    2009-01-01

    Objective: To ascertain maternal expectations and experiences with mealtimes and feeding of toddlers among low-income African American mothers in two mid- to large-size cities in the United States. Design: Qualitative focus group study. Setting: Two Early Head Start programme sites in a Midwestern state which serve low income families. Method:…

  12. A new method for automatic synthesis of tolerances for complex assemblies based on polychromatic sets

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Li, Zongbin; Xu, Lida; Wang, Jikong

    2011-08-01

    In computer-aided tolerance design (CAT), integrated design of dimensional and geometric tolerances is still one of the research hotspots. Polychromatic sets theory (PST) is a new mathematic tool, which is especially suitable for formal hierarchical structure models. Based on PST, in this article, a new hierarchical representation model for tolerance synthesis is presented to realise integrated design of dimensional and geometric tolerances. According to the inference relations between unified and individual colours of PST, the synthesis matrices of variational geometric constraints (VGC) are established in the VGC tier of the model, and the synthesis matrices of tolerance types are established in the tolerance type tier of the model. On this basis, the synthesis processes from the feature tier to the VGC tier and from the VGC tier to the tolerance type tier can be realised. VGCs, which are achieved by the synthesis matrices of VGCs, can be combined together to establish a well-constrained VGC network (VGCN). Tolerance types, which are achieved by the synthesis matrices of tolerance types, can be added to the well-constrained VGCN to construct a well-constrained tolerance network. An application example is given in the article to illustrate the synthesis steps.

  13. Accuracy of genomic selection methods in a standard data set of loblolly pine (Pinus taeda L.).

    PubMed

    Resende, M F R; Muñoz, P; Resende, M D V; Garrick, D J; Fernando, R L; Davis, J M; Jokela, E J; Martin, T A; Peter, G F; Kirst, M

    2012-04-01

    Genomic selection can increase genetic gain per generation through early selection. Genomic selection is expected to be particularly valuable for traits that are costly to phenotype and expressed late in the life cycle of long-lived species. Alternative approaches to genomic selection prediction models may perform differently for traits with distinct genetic properties. Here the performance of four different original methods of genomic selection that differ with respect to assumptions regarding distribution of marker effects, including (i) ridge regression-best linear unbiased prediction (RR-BLUP), (ii) Bayes A, (iii) Bayes Cπ, and (iv) Bayesian LASSO are presented. In addition, a modified RR-BLUP (RR-BLUP B) that utilizes a selected subset of markers was evaluated. The accuracy of these methods was compared across 17 traits with distinct heritabilities and genetic architectures, including growth, development, and disease-resistance properties, measured in a Pinus taeda (loblolly pine) training population of 951 individuals genotyped with 4853 SNPs. The predictive ability of the methods was evaluated using a 10-fold, cross-validation approach, and differed only marginally for most method/trait combinations. Interestingly, for fusiform rust disease-resistance traits, Bayes Cπ, Bayes A, and RR-BLUB B had higher predictive ability than RR-BLUP and Bayesian LASSO. Fusiform rust is controlled by few genes of large effect. A limitation of RR-BLUP is the assumption of equal contribution of all markers to the observed variation. However, RR-BLUP B performed equally well as the Bayesian approaches.The genotypic and phenotypic data used in this study are publically available for comparative analysis of genomic selection prediction models. PMID:22271763

  14. Multiscale optical simulation settings: challenging applications handled with an iterative ray-tracing FDTD interface method.

    PubMed

    Leiner, Claude; Nemitz, Wolfgang; Schweitzer, Susanne; Kuna, Ladislav; Wenzl, Franz P; Hartmann, Paul; Satzinger, Valentin; Sommer, Christian

    2016-03-20

    We show that with an appropriate combination of two optical simulation techniques-classical ray-tracing and the finite difference time domain method-an optical device containing multiple diffractive and refractive optical elements can be accurately simulated in an iterative simulation approach. We compare the simulation results with experimental measurements of the device to discuss the applicability and accuracy of our iterative simulation procedure. PMID:27140556

  15. Physical methods used by Sudanese mothers in rural settings to manage a child with fever

    PubMed Central

    Mukhtar, Hanadi M E; Elnimeiri, Mustafa K

    2014-01-01

    Although the mainstays of antipyretic treatments are drugs such as paracetamol and ibuprofen, physical methods are also used. These include tepid sponging, removing clothes, and cooling the environment with fans to improve ventilation. The objective of this study is to assess the physical methods used by Sudanese rural mothers to manage a child with fever. A cross-sectional descriptive study was designed and conducted within 6 months; it involved 332 mothers of children under five. The data were collected through using a standardized administered questionnaire and focus group discussion and analyzed by statistical package for social science version 15.0 (SPSS). Tepid sponging was used by 47% of the interviewed mothers. 15% of the mothers increased fluid intake, 7% bathed the child and 5% put the child in light clothes. 59% of mothers applied tepid sponging on head, 33.9% on all the body, 3.7% and 2.2% on groin area and axilla, respectively. The majority of mothers (86%) used water from refrigerator or zeir [water clay pot] for applying tepid sponging, 9% used tap water, and 3% used ice water. In conclusion, this study revealed that the common physical treatment method for fever used by mothers was tepid sponging with inappropriate application. PMID:27493391

  16. Reducing the Cognitive Complexity Associated with Standard Setting: A Comparison of the Single-Passage Bookmark and Yes/No Methods

    ERIC Educational Resources Information Center

    Skaggs, Gary; Hein, Serge F.

    2011-01-01

    Judgmental standard setting methods have been criticized for the cognitive complexity of the judgment task that panelists are asked to complete. This study compared two methods designed to reduce this complexity: the yes/no method and the single-passage bookmark method. Two mock standard setting panel meetings were convened, one for each method,…

  17. A comparison of the oral and silent reading methods of standardized science test delivery on the performance level of fifth-grade African American students

    NASA Astrophysics Data System (ADS)

    Merenda, Gloria Louise

    This study compared two methods of standardized test administration, oral delivery using an audio tape and the standard silent reading by the student, on the performance level (test score) and science understanding (right answer/right reason) of urban fifth grade African American students. The effect of reading ability, special needs, and socioeconomic status were also examined as possible confounding variables. A randomized post-test only control group design was used with data for the sample (N = 106) collected from student files at two Detroit Public Schools, which included the Michigan Education Assessment Program (MEAP) reading and science scores. In addition, face-to-face interviews were completed with a small subsample to determine reasoning for selecting their answers. Six hypotheses were developed to determine if there were significant differences in science performance level and understanding in fifth grade urban African American students when the standardized science test, MEAP, Area Specific Portions, Physical Science and Earth/Space Science, were delivered orally, using the audio tape, and silently, which is the present standard delivery method. Significant differences in scores were found favoring the oral over the silent test group. A significant association was also found for reading and science MEAP scores, with students who had higher scores on the reading test achieving higher scores on the science test. Although socioeconomic status did not appear to result in differential outcomes among the students, a significant interaction was found between test administration type and socioeconomic status. The conclusion that was reached was that students who have difficulty in reading the printed material could benefit from having standardized tests administered orally (except for reading tests).

  18. Experiments and other methods for developing expertise with design of experiments in a classroom setting

    NASA Technical Reports Server (NTRS)

    Patterson, John W.

    1990-01-01

    The only way to gain genuine expertise in Statistical Process Control (SPC) and the design of experiments (DOX) is with repeated practice, but not on canned problems with dead data sets. Rather, one must negotiate a wide variety of problems each with its own peculiarities and its own constantly changing data. The problems should not be of the type for which there is a single, well-defined answer that can be looked up in a fraternity file or in some text. The problems should match as closely as possible the open-ended types for which there is always an abundance of uncertainty. These are the only kinds that arise in real research, whether that be basic research in academe or engineering research in industry. To gain this kind of experience, either as a professional consultant or as an industrial employee, takes years. Vast amounts of money, not to mention careers, must be put at risk. The purpose here is to outline some realistic simulation-type lab exercises that are so simple and inexpensive to run that the students can repeat them as often as desired at virtually no cost. Simulations also allow the instructor to design problems whose outcomes are as noisy as desired but still predictable within limits. Also the instructor and the students can learn a great deal more from the postmortum conducted after the exercise is completed. One never knows for sure what the true data should have been when dealing only with real life experiments. To add a bit more realism to the exercises, it is sometimes desirable to make the students pay for each experimental result from a make-believe budget allocation for the problem.

  19. Application of biclustering of gene expression data and gene set enrichment analysis methods to identify potentially disease causing nanomaterials

    PubMed Central

    Halappanavar, Sabina

    2015-01-01

    Summary Background: The presence of diverse types of nanomaterials (NMs) in commerce is growing at an exponential pace. As a result, human exposure to these materials in the environment is inevitable, necessitating the need for rapid and reliable toxicity testing methods to accurately assess the potential hazards associated with NMs. In this study, we applied biclustering and gene set enrichment analysis methods to derive essential features of altered lung transcriptome following exposure to NMs that are associated with lung-specific diseases. Several datasets from public microarray repositories describing pulmonary diseases in mouse models following exposure to a variety of substances were examined and functionally related biclusters of genes showing similar expression profiles were identified. The identified biclusters were then used to conduct a gene set enrichment analysis on pulmonary gene expression profiles derived from mice exposed to nano-titanium dioxide (nano-TiO2), carbon black (CB) or carbon nanotubes (CNTs) to determine the disease significance of these data-driven gene sets. Results: Biclusters representing inflammation (chemokine activity), DNA binding, cell cycle, apoptosis, reactive oxygen species (ROS) and fibrosis processes were identified. All of the NM studies were significant with respect to the bicluster related to chemokine activity (DAVID; FDR p-value = 0.032). The bicluster related to pulmonary fibrosis was enriched in studies where toxicity induced by CNT and CB studies was investigated, suggesting the potential for these materials to induce lung fibrosis. The pro-fibrogenic potential of CNTs is well established. Although CB has not been shown to induce fibrosis, it induces stronger inflammatory, oxidative stress and DNA damage responses than nano-TiO2 particles. Conclusion: The results of the analysis correctly identified all NMs to be inflammogenic and only CB and CNTs as potentially fibrogenic. In addition to identifying several

  20. Simulation of the electrode shape change in electrochemical machining based on the level set method

    NASA Astrophysics Data System (ADS)

    Topa, V.; Purcar, M.; Avram, A.; Munteanu, C.; Chereches, R.; Grindei, L.

    2012-04-01

    This paper proposes a generally applicable numerical algorithm for the simulation of two dimensional electrode shape changes during electrochemical machining processes. The computational model consists of two coupled problems: an electrode shape change rate analysis and a moving boundary problem. The innovative aspect is that the workpiece shape is computed over a number of predefined time steps by convection of its surface with a velocity proportional and in the direction of the local electrode shape change rate. An example related to the electrochemical machining of a slot in a stainless steel plate is presented here to demonstrate the strong features of the proposed method.

  1. A practical method of predicting client revisit intention in a hospital setting.

    PubMed

    Lee, Kyun Jick

    2005-01-01

    Data mining (DM) models are an alternative to traditional statistical methods for examining whether higher customer satisfaction leads to higher revisit intention. This study used a total of 906 outpatients' satisfaction data collected from a nationwide survey interviews conducted by professional interviewers on a face-to-face basis in South Korea, 1998. Analyses showed that the relationship between overall satisfaction with hospital services and outpatients' revisit intention, along with word-of-mouth recommendation as intermediate variables, developed into a nonlinear relationship. The five strongest predictors of revisit intention were overall satisfaction, intention to recommend to others, awareness of hospital promotion, satisfaction with physician's kindness, and satisfaction with treatment level. PMID:15923917

  2. Differences in the Tumor Microenvironment between African-American and European-American Breast Cancer Patients

    PubMed Central

    Martin, Damali N.; Boersma, Brenda J.; Yi, Ming; Reimers, Mark; Howe, Tiffany M.; Yfantis, Harry G.; Tsai, Yien Che; Williams, Erica H.; Lee, Dong H.; Stephens, Robert M.; Weissman, Allan M.; Ambs, Stefan

    2009-01-01

    Background African-American breast cancer patients experience higher mortality rates than European-American patients despite having a lower incidence of the disease. We tested the hypothesis that intrinsic differences in the tumor biology may contribute to this cancer health disparity. Methods and Results Using laser capture microdissection, we examined genome-wide mRNA expression specific to tumor epithelium and tumor stroma in 18 African-American and 17 European-American patients. Numerous genes were differentially expressed between these two patient groups and a two-gene signature in the tumor epithelium distinguished between them. To identify the biological processes in tumors that are different by race/ethnicity, Gene Ontology and disease association analyses were performed. Several biological processes were identified which may contribute to enhanced disease aggressiveness in African-American patients, including angiogenesis and chemotaxis. African-American tumors also contained a prominent interferon signature. The role of angiogenesis in the tumor biology of African-Americans was further investigated by examining the extent of vascularization and macrophage infiltration in an expanded set of 248 breast tumors. Immunohistochemistry revealed that microvessel density and macrophage infiltration is higher in tumors of African-Americans than in tumors of European-Americans. Lastly, using an in silico approach, we explored the potential of tailored treatment options for African-American patients based on their gene expression profile. This exploratory approach generated lists of therapeutics that may have specific antagonistic activity against tumors of African-American patients, e.g., sirolimus, resveratrol, and chlorpromazine in estrogen receptor-negative tumors. Conclusions The gene expression profiles of breast tumors indicate that differences in tumor biology may exist between African-American and European-American patients beyond the knowledge of current

  3. Experiences with Capnography in Acute Care Settings: A Mixed-Methods Analysis of Clinical Staff

    PubMed Central

    Langhan, Melissa L.; Kurtz, Jordan C.; Schaeffer, Paula; Asnes, Andrea G.; Riera, Antonio

    2014-01-01

    Purpose While capnography is being incorporated into clinical guidelines, it is not used to it's full potential. We investigated reasons for limited implementation of capnography in acute care areas and explored facilitators and barriers to its implementation. Methods A purposeful sample of physicians and nurses in emergency departments (ED) and intensive care units (ICU) participated in semistructured interviews. Grounded theory, iterative data analysis and the constant comparative method were used to analyze the data to inductively generate ideas and build theories. Results Nineteen providers were interviewed from five hospitals. Six themes were identified: variability in use of capnography among acute care units, availability and accessibility of capnography equipment, the evidence behind capnography use, the impact of capnography on patient care, personal experiences impacting use of capnography, and variable knowledge about capnography. Barriers and facilitators to use were found within each theme. Conclusions We observed varied responsiveness to capnography and identified factors that work to foster or discourage its use. This data can guide future implementation strategies. A deliberate strategy to foster utilization, mitigate barriers and broadly accelerate implementation has the potential to profoundly impact use of capnography in acute care areas with the goal of improving patient care. PMID:25129575

  4. Long-stroke fast tool servo and a tool setting method for freeform optics fabrication

    NASA Astrophysics Data System (ADS)

    Liu, Qiang; Zhou, Xiaoqin; Liu, Zhiwei; Lin, Chao; Ma, Long

    2014-09-01

    Diamond turning assisted by fast tool servo is of high efficiency for the fabrication of freeform optics. This paper describes a long-stroke fast tool servo to obtain a large-amplitude tool motion. It has the advantage of low cost and higher stiffness and natural frequency than other flexure-based long-stroke fast tool servo systems. The fast tool servo is actuated by a voice coil motor and guided by a flexure-hinge structure. Open-loop and close-loop control tests are conducted on the testing platform. While fast tool servo system is an additional motion axis for a diamond turning machine, a tool center adjustment method is described to confirm tool center position in the machine tool coordinate system when the fast tool servo system is fixed on the diamond turning machine. Last, a sinusoidal surface is machined and the results demonstrate that the tool adjustment method is efficient and precise for a flexure-based fast tool servo system, and the fast tool servo system works well on the fabrication of freeform optics.

  5. Comparison of image segmentation of lungs using methods: connected threshold, neighborhood connected, and threshold level set segmentation

    NASA Astrophysics Data System (ADS)

    Amanda, A. R.; Widita, R.

    2016-03-01

    The aim of this research is to compare some image segmentation methods for lungs based on performance evaluation parameter (Mean Square Error (MSE) and Peak Signal Noise to Ratio (PSNR)). In this study, the methods compared were connected threshold, neighborhood connected, and the threshold level set segmentation on the image of the lungs. These three methods require one important parameter, i.e the threshold. The threshold interval was obtained from the histogram of the original image. The software used to segment the image here was InsightToolkit-4.7.0 (ITK). This research used 5 lung images to be analyzed. Then, the results were compared using the performance evaluation parameter determined by using MATLAB. The segmentation method is said to have a good quality if it has the smallest MSE value and the highest PSNR. The results show that four sample images match the criteria of connected threshold, while one sample refers to the threshold level set segmentation. Therefore, it can be concluded that connected threshold method is better than the other two methods for these cases.

  6. Set up an Arc Welding Code with Enthalpy Method in Upwind Scheme

    SciTech Connect

    Ho, J.-E.

    2010-05-21

    In this study, a numerical code with enthalpy method in upwind scheme is proposed to estimate the distribution of thermal stress in the molten pool, which is primarily determined by the type of the input power and travel speed of heating source. To predict the cracker deficit inside the workpiece, a simulated program satisfying the diagonal domination and Scarborough criterion provides a stable iteration. Meantime, an experimental performance, operated by robot arm 'DR-400' to provide a steady and continuous arc welding, was also conducted to verify the simulated result. By surveying the consistence of molten pool bounded by contrast shade and simulated melting contour on the surface of workpiece, the validity of model proposed to predict the thermal cracker has been successfully identified.

  7. Leveraging Administrative Data for Program Evaluations: A Method for Linking Data Sets Without Unique Identifiers.

    PubMed

    Lorden, Andrea L; Radcliff, Tiffany A; Jiang, Luohua; Horel, Scott A; Smith, Matthew L; Lorig, Kate; Howell, Benjamin L; Whitelaw, Nancy; Ory, Marcia

    2016-06-01

    In community-based wellness programs, Social Security Numbers (SSNs) are rarely collected to encourage participation and protect participant privacy. One measure of program effectiveness includes changes in health care utilization. For the 65 and over population, health care utilization is captured in Medicare administrative claims data. Therefore, methods as described in this article for linking participant information to administrative data are useful for program evaluations where unique identifiers such as SSN are not available. Following fuzzy matching methodologies, participant information from the National Study of the Chronic Disease Self-Management Program was linked to Medicare administrative data. Linking variables included participant name, date of birth, gender, address, and ZIP code. Seventy-eight percent of participants were linked to their Medicare claims data. Linking program participant information to Medicare administrative data where unique identifiers are not available provides researchers with the ability to leverage claims data to better understand program effects. PMID:25139849

  8. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  9. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  10. Method and basis set dependence of anharmonic ground state nuclear wave functions and zero-point energies: Application to SSSH

    NASA Astrophysics Data System (ADS)

    Kolmann, Stephen J.; Jordan, Meredith J. T.

    2010-02-01

    One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol-1 at the CCSD(T)/6-31G∗ level of theory, has a 4 kJ mol-1 dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol-1 lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol-1 lower in energy at the CCSD(T)/6-31G∗ level of theory. Ideally, for sub-kJ mol-1 thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented.

  11. Method and basis set dependence of anharmonic ground state nuclear wave functions and zero-point energies: application to SSSH.

    PubMed

    Kolmann, Stephen J; Jordan, Meredith J T

    2010-02-01

    One of the largest remaining errors in thermochemical calculations is the determination of the zero-point energy (ZPE). The fully coupled, anharmonic ZPE and ground state nuclear wave function of the SSSH radical are calculated using quantum diffusion Monte Carlo on interpolated potential energy surfaces (PESs) constructed using a variety of method and basis set combinations. The ZPE of SSSH, which is approximately 29 kJ mol(-1) at the CCSD(T)/6-31G* level of theory, has a 4 kJ mol(-1) dependence on the treatment of electron correlation. The anharmonic ZPEs are consistently 0.3 kJ mol(-1) lower in energy than the harmonic ZPEs calculated at the Hartree-Fock and MP2 levels of theory, and 0.7 kJ mol(-1) lower in energy at the CCSD(T)/6-31G* level of theory. Ideally, for sub-kJ mol(-1) thermochemical accuracy, ZPEs should be calculated using correlated methods with as big a basis set as practicable. The ground state nuclear wave function of SSSH also has significant method and basis set dependence. The analysis of the nuclear wave function indicates that SSSH is localized to a single symmetry equivalent global minimum, despite having sufficient ZPE to be delocalized over both minima. As part of this work, modifications to the interpolated PES construction scheme of Collins and co-workers are presented. PMID:20136303

  12. Using a Mixed Methods Sequential Design to Identify Factors Associated with African American Mothers' Intention to Vaccinate Their Daughters Aged 9 to 12 for HPV with a Purpose of Informing a Culturally-Relevant, Theory-Based Intervention

    ERIC Educational Resources Information Center

    Cunningham, Jennifer L.

    2013-01-01

    The purpose of this sequential, explanatory mixed methods research study was to understand what factors influenced African American maternal intentions to get their daughters aged 9 years to 12 years vaccinated in Alabama. In the first, quantitative phase of the study, the research questions focused on identifying the predictive power of eleven…

  13. System and method for the adaptive mapping of matrix data to sets of polygons

    NASA Technical Reports Server (NTRS)

    Burdon, David (Inventor)

    2003-01-01

    A system and method for converting bitmapped data, for example, weather data or thermal imaging data, to polygons is disclosed. The conversion of the data into polygons creates smaller data files. The invention is adaptive in that it allows for a variable degree of fidelity of the polygons. Matrix data is obtained. A color value is obtained. The color value is a variable used in the creation of the polygons. A list of cells to check is determined based on the color value. The list of cells to check is examined in order to determine a boundary list. The boundary list is then examined to determine vertices. The determination of the vertices is based on a prescribed maximum distance. When drawn, the ordered list of vertices create polygons which depict the cell data. The data files which include the vertices for the polygons are much smaller than the corresponding cell data files. The fidelity of the polygon representation can be adjusted by repeating the logic with varying fidelity values to achieve a given maximum file size or a maximum number of vertices per polygon.

  14. Using the mystery box as a means to explore the scientific method in an undergraduate lecture setting

    NASA Astrophysics Data System (ADS)

    Cook, H. M.; Cook, G. W.

    2015-12-01

    The mystery box is a well-known and well-loved teaching tool designed to encourage students to engage in making observations in order to draw conclusions. We have adapted this exercise, normally used in laboratory settings, for use in a lecture setting in introductory earth science classes. We have tied it to the scientific method such that students are engaging in mystery-box- based inquiry while exploring the steps of the scientific method. It is used in conjunction with a PowerPoint presentation that illustrates and discusses the steps and process integral to the scientific method, which is fundamental to science. Students are encouraged to explore the formal and informal use of the scientific method throughout their educational careers and in their daily lives. Furthermore, students are challenged to analyze the necessity of the scientific method as means for conducting scientific inquiry and exploring the results of such inquiry. A follow-up assignment to the activity asks students to evaluate the efficacy of the activity and associated PowerPoint and discussion. Students consistently report having enjoyed and learned from the process.

  15. An African ethic for nursing?

    PubMed

    Haegert, S

    2000-11-01

    This article derives from a doctoral thesis in which a particular discourse was used as a 'paradigm case'. From this discourse an ethic set within a South African culture arose. Using many cultural 'voices' to aid the understanding of this narrative, the ethic shows that one can build on both a 'justice' and a 'care' ethic. With further development based on African culture one can take the ethic of care deeper and reveal 'layers of understanding'. Care, together with compassion, forms the foundation of morality. Nursing ethics has followed particular western moral philosophers. Often nursing ethics has been taught along the lines of Kohlberg's theory of morality, with its emphasis on rules, rights, duties and general obligations. These principles were universalistic, masculine and noncontextual. However, there is a new ethical movement among Thomist philosophers along the lines to be expounded in this article. Nurses such as Benner, Bevis, Dunlop, Fry and Gadow--to name but a few--have welcomed the concept of an 'ethic of care'. Gilligan's work gave a feminist view and situated ethics in the everyday aspects of responsiveness, responsibility, context and concern. Shutte's search for a 'philosophy for Africa' has resulted in finding similarities in Setiloane and in Senghor with those of Thomist philosophers. Using this African philosophy and a research participant's narrative, an African ethic evolves out of the African proverb: 'A person is a person through other persons', or its alternative rendering: 'I am because we are: we are because I am.' This hermeneutic narrative reveals 'the way affect imbues activity with ethical meaning' within the context of a black nursing sister in a rural South African hospital. It expands upon the above proverb and incorporates the South African constitutional idea of 'Ubuntu' (compassion and justice or humanness). PMID:11221391

  16. Simulation modeling based method for choosing an effective set of fault tolerance mechanisms for real-time avionics systems

    NASA Astrophysics Data System (ADS)

    Bakhmurov, A. G.; Balashov, V. V.; Glonina, A. B.; Pashkov, V. N.; Smeliansky, R. L.; Volkanov, D. Yu.

    2013-12-01

    In this paper, the reliability allocation problem (RAP) for real-time avionics systems (RTAS) is considered. The proposed method for solving this problem consists of two steps: (i) creation of an RTAS simulation model at the necessary level of abstraction and (ii) application of metaheuristic algorithm to find an optimal solution (i. e., to choose an optimal set of fault tolerance techniques). When during the algorithm execution it is necessary to measure the execution time of some software components, the simulation modeling is applied. The procedure of simulation modeling also consists of the following steps: automatic construction of simulation model of the RTAS configuration and running this model in a simulation environment to measure the required time. This method was implemented as an experimental software tool. The tool works in cooperation with DYANA simulation environment. The results of experiments with the implemented method are presented. Finally, future plans for development of the presented method and tool are briefly described.

  17. Tests of one Brazilian facial reconstruction method using three soft tissue depth sets and familiar assessors.

    PubMed

    Fernandes, Clemente Maia S; Serra, Mônica da Costa; da Silva, Jorge Vicente Lopes; Noritomi, Pedro Yoshito; Pereira, Frederico David Alencar de Sena; Melani, Rodolfo Francisco Haltenhoff

    2012-01-10

    Facial reconstruction is a method that seeks to recreate a person's facial appearance from his/her skull. This technique can be the last resource used in a forensic investigation, when identification techniques such as DNA analysis, dental records, fingerprints and radiographic comparison cannot be used to identify a body or skeletal remains. To perform facial reconstruction, the data of facial soft tissue thickness are necessary. Scientific literature has described differences in the thickness of facial soft tissue between ethnic groups. There are different databases of soft tissue thickness published in the scientific literature. There are no literature records of facial reconstruction works carried out with data of soft tissues obtained from samples of Brazilian subjects. There are also no reports of digital forensic facial reconstruction performed in Brazil. There are two databases of soft tissue thickness published for the Brazilian population: one obtained from measurements performed in fresh cadavers (fresh cadavers' pattern), and another from measurements using magnetic resonance imaging (Magnetic Resonance pattern). This study aims to perform three different characterized digital forensic facial reconstructions (with hair, eyelashes and eyebrows) of a Brazilian subject (based on an international pattern and two Brazilian patterns for soft facial tissue thickness), and evaluate the digital forensic facial reconstructions comparing them to photos of the individual and other nine subjects. The DICOM data of the Computed Tomography (CT) donated by a volunteer were converted into stereolitography (STL) files and used for the creation of the digital facial reconstructions. Once the three reconstructions were performed, they were compared to photographs of the subject who had the face reconstructed and nine other subjects. Thirty examiners participated in this recognition process. The target subject was recognized by 26.67% of the examiners in the reconstruction

  18. How valid is the tallquist method in screening pregnant women with anemia in poor rural settings of southwestern Nigeria?

    PubMed Central

    Wasiu Olalekan, Adebimpe; Olufemi Emmanuel, Akanni

    2016-01-01

    Background: Diagnosis of anemia is challenging in resource-poor settings due to inadequate laboratory resources. This study assessed the validity of the Tallquist haemoglobinometer in assessing anemia among pregnant women in Osogbo, Southwestern Nigeria. Methods: This was a cross - sectional study, in which 200 pregnant women of reproductive age were selected using multistage sapling method. A checklist was used to collect socio-demographic data and the results of the screening test. Blood collection and analysis were carried out using standardized referenced methods. Results: Mean±SD age of the respondents was 28.9+3.9 yrs.; and 62 (62.6%) had up to primary level education. When Tallquist and Haematocrit methods were compared, there was 68.4%, 83.5% and 100% likelihood of Tallquist method (TM) diagnosing severe, moderate and mild anemia, respectively. The validity indices of the TM versus Haematocrit method as the gold standard revealed the sensitivity of 97.9%, specificity of 92.1%, positive predictive value of 92.4%, and negative predictive value of 97.9% and diagnostic accuracy of 95.0%. When compared to the Haemoglobin Cyanide method, the Tallquist method showed a calculated sensitivity of 96.6%, specificity of 87.4%, positive predictive value of 86.0%, and negative predictive value of 97.0% and diagnostic accuracy of 91.5%. Conclusion: The TM is a valid tool in screening anemia among pregnant women in resource- poor settings and rural primary health care centers in Southwestern Nigeria; therefore, its use should be encouraged, particularly to assess mild to moderate anemia. PMID:27493933

  19. Degeneracy relations in QCD and the equivalence of two systematic all-orders methods for setting the renormalization scale

    SciTech Connect

    Bi, Huan -Yu; Wu, Xing -Gang; Ma, Yang; Ma, Hong -Hao; Brodsky, Stanley J.; Mojaza, Matin

    2015-06-26

    The Principle of Maximum Conformality (PMC) eliminates QCD renormalization scale-setting uncertainties using fundamental renormalization group methods. The resulting scale-fixed pQCD predictions are independent of the choice of renormalization scheme and show rapid convergence. The coefficients of the scale-fixed couplings are identical to the corresponding conformal series with zero β-function. Two all-orders methods for systematically implementing the PMC-scale setting procedure for existing high order calculations are discussed in this article. One implementation is based on the PMC-BLM correspondence (PMC-I); the other, more recent, method (PMC-II) uses the Rδ-scheme, a systematic generalization of the minimal subtraction renormalization scheme. Both approaches satisfy all of the principles of the renormalization group and lead to scale-fixed and scheme-independent predictions at each finite order. In this work, we show that PMC-I and PMC-II scale-setting methods are in practice equivalent to each other. We illustrate this equivalence for the four-loop calculations of the annihilation ratio Re+e and the Higgs partial width I'(H→bb¯). Both methods lead to the same resummed (‘conformal’) series up to all orders. The small scale differences between the two approaches are reduced as additional renormalization group {βi}-terms in the pQCD expansion are taken into account. In addition, we show that special degeneracy relations, which underly the equivalence of the two PMC approaches and the resulting conformal features of the pQCD series, are in fact general properties of non-Abelian gauge theory.

  20. Degeneracy relations in QCD and the equivalence of two systematic all-orders methods for setting the renormalization scale

    NASA Astrophysics Data System (ADS)

    Bi, Huan-Yu; Wu, Xing-Gang; Ma, Yang; Ma, Hong-Hao; Brodsky, Stanley J.; Mojaza, Matin

    2015-09-01

    The Principle of Maximum Conformality (PMC) eliminates QCD renormalization scale-setting uncertainties using fundamental renormalization group methods. The resulting scale-fixed pQCD predictions are independent of the choice of renormalization scheme and show rapid convergence. The coefficients of the scale-fixed couplings are identical to the corresponding conformal series with zero β-function. Two all-orders methods for systematically implementing the PMC-scale setting procedure for existing high order calculations are discussed in this article. One implementation is based on the PMC-BLM correspondence (PMC-I); the other, more recent, method (PMC-II) uses the Rδ-scheme, a systematic generalization of the minimal subtraction renormalization scheme. Both approaches satisfy all of the principles of the renormalization group and lead to scale-fixed and scheme-independent predictions at each finite order. In this work, we show that PMC-I and PMC-II scale-setting methods are in practice equivalent to each other. We illustrate this equivalence for the four-loop calculations of the annihilation ratio Re+e- and the Higgs partial width Γ (H → b b bar). Both methods lead to the same resummed ('conformal') series up to all orders. The small scale differences between the two approaches are reduced as additional renormalization group {βi }-terms in the pQCD expansion are taken into account. We also show that special degeneracy relations, which underly the equivalence of the two PMC approaches and the resulting conformal features of the pQCD series, are in fact general properties of non-Abelian gauge theory.

  1. Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions.

    PubMed

    Nikolaev, A V; Lamoen, D; Partoens, B

    2016-07-01

    In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the u̇l-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets. PMID:27394093

  2. A Kernel Machine Method for Detecting Effects of Interaction Between Multidimensional Variable Sets: An Imaging Genetics Application

    PubMed Central

    Ge, Tian; Nichols, Thomas E.; Ghosh, Debashis; Mormino, Elizabeth C.

    2015-01-01

    Measurements derived from neuroimaging data can serve as markers of disease and/or healthy development, are largely heritable, and have been increasingly utilized as (intermediate) phenotypes in genetic association studies. To date, imaging genetic studies have mostly focused on discovering isolated genetic effects, typically ignoring potential interactions with non-genetic variables such as disease risk factors, environmental exposures, and epigenetic markers. However, identifying significant interaction effects is critical for revealing the true relationship between genetic and phenotypic variables, and shedding light on disease mechanisms. In this paper, we present a general kernel machine based method for detecting effects of interaction between multidimensional variable sets. This method can model the joint and epistatic effect of a collection of single nucleotide polymorphisms (SNPs), accommodate multiple factors that potentially moderate genetic influences, and test for nonlinear interactions between sets of variables in a flexible framework. As a demonstration of application, we applied the method to data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to detect the effects of the interactions between candidate Alzheimer's disease (AD) risk genes and a collection of cardiovascular disease (CVD) risk factors, on hippocampal volume measurements derived from structural brain magnetic resonance imaging (MRI) scans. Our method identified that two genes, CR1 and EPHA1, demonstrate significant interactions with CVD risk factors on hippocampal volume, suggesting that CR1 and EPHA1 may play a role in influencing AD-related neurodegeneration in the presence of CVD risks. PMID:25600633

  3. A kernel machine method for detecting effects of interaction between multidimensional variable sets: an imaging genetics application.

    PubMed

    Ge, Tian; Nichols, Thomas E; Ghosh, Debashis; Mormino, Elizabeth C; Smoller, Jordan W; Sabuncu, Mert R

    2015-04-01

    Measurements derived from neuroimaging data can serve as markers of disease and/or healthy development, are largely heritable, and have been increasingly utilized as (intermediate) phenotypes in genetic association studies. To date, imaging genetic studies have mostly focused on discovering isolated genetic effects, typically ignoring potential interactions with non-genetic variables such as disease risk factors, environmental exposures, and epigenetic markers. However, identifying significant interaction effects is critical for revealing the true relationship between genetic and phenotypic variables, and shedding light on disease mechanisms. In this paper, we present a general kernel machine based method for detecting effects of the interaction between multidimensional variable sets. This method can model the joint and epistatic effect of a collection of single nucleotide polymorphisms (SNPs), accommodate multiple factors that potentially moderate genetic influences, and test for nonlinear interactions between sets of variables in a flexible framework. As a demonstration of application, we applied the method to the data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) to detect the effects of the interactions between candidate Alzheimer's disease (AD) risk genes and a collection of cardiovascular disease (CVD) risk factors, on hippocampal volume measurements derived from structural brain magnetic resonance imaging (MRI) scans. Our method identified that two genes, CR1 and EPHA1, demonstrate significant interactions with CVD risk factors on hippocampal volume, suggesting that CR1 and EPHA1 may play a role in influencing AD-related neurodegeneration in the presence of CVD risks. PMID:25600633

  4. A primal-dual active-set method for non-negativity constrained total variation deblurring problems.

    PubMed

    Krishnan, D; Lin, Ping; Yip, Andy M

    2007-11-01

    This paper studies image deblurring problems using a total variation-based model, with a non-negativity constraint. The addition of the non-negativity constraint improves the quality of the solutions, but makes the solution process a difficult one. The contribution of our work is a fast and robust numerical algorithm to solve the non-negatively constrained problem. To overcome the nondifferentiability of the total variation norm, we formulate the constrained deblurring problem as a primal-dual program which is a variant of the formulation proposed by Chan, Golub, and Mulet for unconstrained problems. Here, dual refers to a combination of the Lagrangian and Fenchel duals. To solve the constrained primal-dual program, we use a semi-smooth Newton's method. We exploit the relationship between the semi-smooth Newton's method and the primal-dual active set method to achieve considerable simplification of the computations. The main advantages of our proposed scheme are: no parameters need significant adjustment, a standard inverse preconditioner works very well, quadratic rate of local convergence (theoretical and numerical), numerical evidence of global convergence, and high accuracy of solving the optimality system. The scheme shows robustness of performance over a wide range of parameters. A comprehensive set of numerical comparisons are provided against other methods to solve the same problem which show the speed and accuracy advantages of our scheme. PMID:17990753

  5. Methods to characterize environmental settings of stream and groundwater sampling sites for National Water-Quality Assessment

    USGS Publications Warehouse

    Nakagaki, Naomi; Hitt, Kerie J.; Price, Curtis V.; Falcone, James A.

    2012-01-01

    Characterization of natural and anthropogenic features that define the environmental settings of sampling sites for streams and groundwater, including drainage basins and groundwater study areas, is an essential component of water-quality and ecological investigations being conducted as part of the U.S. Geological Survey's National Water-Quality Assessment program. Quantitative characterization of environmental settings, combined with physical, chemical, and biological data collected at sampling sites, contributes to understanding the status of, and influences on, water-quality and ecological conditions. To support studies for the National Water-Quality Assessment program, a geographic information system (GIS) was used to develop a standard set of methods to consistently characterize the sites, drainage basins, and groundwater study areas across the nation. This report describes three methods used for characterization-simple overlay, area-weighted areal interpolation, and land-cover-weighted areal interpolation-and their appropriate applications to geographic analyses that have different objectives and data constraints. In addition, this document records the GIS thematic datasets that are used for the Program's national design and data analyses.

  6. Robust, basis-set independent method for the evaluation of charge-transfer energy in noncovalent complexes.

    PubMed

    Řezáč, Jan; de la Lande, Aurélien

    2015-02-10

    Separation of the energetic contribution of charge transfer to interaction energy in noncovalent complexes would provide important insight into the mechanisms of the interaction. However, the calculation of charge-transfer energy is not an easy task. It is not a physically well-defined term, and the results might depend on how it is described in practice. Commonly, the charge transfer is defined in terms of molecular orbitals; in this framework, however, the charge transfer vanishes as the basis set size increases toward the complete basis set limit. This can be avoided by defining the charge transfer in terms of the spatial extent of the electron densities of the interacting molecules, but the schemes used so far do not reflect the actual electronic structure of each particular system and thus are not reliable. We propose a spatial partitioning of the system, which is based on a charge transfer-free reference state, namely superimposition of electron densities of the noninteracting fragments. We show that this method, employing constrained DFT for the calculation of the charge-transfer energy, yields reliable results and is robust with respect to the strength of the charge transfer, the basis set size, and the DFT functional used. Because it is based on DFT, the method is applicable to rather large systems. PMID:26580910

  7. A Degenerate Primer MOB Typing (DPMT) Method to Classify Gamma-Proteobacterial Plasmids in Clinical and Environmental Settings

    PubMed Central

    de la Cruz, Fernando

    2012-01-01

    Transmissible plasmids are responsible for the spread of genetic determinants, such as antibiotic resistance or virulence traits, causing a large ecological and epidemiological impact. Transmissible plasmids, either conjugative or mobilizable, have in common the presence of a relaxase gene. Relaxases were previously classified in six protein families according to their phylogeny. Degenerate primers hybridizing to coding sequences of conserved amino acid motifs were designed to amplify related relaxase genes from γ-Proteobacterial plasmids. Specificity and sensitivity of a selected set of 19 primer pairs were first tested using a collection of 33 reference relaxases, representing the diversity of γ-Proteobacterial plasmids. The validated set was then applied to the analysis of two plasmid collections obtained from clinical isolates. The relaxase screening method, which we call “Degenerate Primer MOB Typing” or DPMT, detected not only most known Inc/Rep groups, but also a plethora of plasmids not previously assigned to any Inc group or Rep-type. PMID:22792321

  8. Approximate method for predicting the permanent set in a beam in vacuo and in water subject to a shock wave

    NASA Technical Reports Server (NTRS)

    Stiehl, A. L.; Haberman, R. C.; Cowles, J. H.

    1988-01-01

    An approximate method to compute the maximum deformation and permanent set of a beam subjected to shock wave laoding in vacuo and in water was investigated. The method equates the maximum kinetic energy of the beam (and water) to the elastic plastic work done by a static uniform load applied to a beam. Results for the water case indicate that the plastic deformation is controlled by the kinetic energy of the water. The simplified approach can result in significant savings in computer time or it can expediently be used as a check of results from a more rigorous approach. The accuracy of the method is demonstrated by various examples of beams with simple support and clamped support boundary conditions.

  9. A discriminant function model as an alternative method to spirometry for COPD screening in primary care settings in China

    PubMed Central

    Cui, Jiangyu; Zhou, Yumin; Tian, Jia; Wang, Xinwang; Zheng, Jingping; Zhong, Nanshan

    2012-01-01

    Objective COPD is often underdiagnosed in a primary care setting where the spirometry is unavailable. This study was aimed to develop a simple, economical and applicable model for COPD screening in those settings. Methods First we established a discriminant function model based on Bayes’ Rule by stepwise discriminant analysis, using the data from 243 COPD patients and 112 non-COPD subjects from our COPD survey in urban and rural communities and local primary care settings in Guangdong Province, China. We then used this model to discriminate COPD in additional 150 subjects (50 non-COPD and 100 COPD ones) who had been recruited by the same methods as used to have established the model. All participants completed pre- and post-bronchodilator spirometry and questionnaires. COPD was diagnosed according to the Global Initiative for Chronic Obstructive Lung Disease criteria. The sensitivity and specificity of the discriminant function model was assessed. Results The established discriminant function model included nine variables: age, gender, smoking index, body mass index, occupational exposure, living environment, wheezing, cough and dyspnoea. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, accuracy and error rate of the function model to discriminate COPD were 89.00%, 82.00%, 4.94, 0.13, 86.66% and 13.34%, respectively. The accuracy and Kappa value of the function model to predict COPD stages were 70% and 0.61 (95% CI, 0.50 to 0.71). Conclusions This discriminant function model may be used for COPD screening in primary care settings in China as an alternative option instead of spirometry. PMID:23205284

  10. Implicit Stereotyping and Medical Decisions: Unconscious Stereotype Activation in Practitioners' Thoughts About African Americans

    PubMed Central

    Stone, Jeff; Childs, Amanda

    2012-01-01

    Objectives. We investigated whether stereotypes unconsciously influence the thinking and behavior of physicians, as they have been shown to do in other professional settings, such as among law enforcement personnel and teachers. Methods. We conducted 2 studies to examine whether stereotypes are implicitly activated in physicians. Study 1 assessed what diseases and treatments doctors associate with African Americans. Study 2 presented these (and control terms) to doctors as part of a computerized task. Subliminal images of African American and White men appeared prior to each word, and reaction times to words were recorded. Results. When primed with an African American face, doctors reacted more quickly for stereotypical diseases, indicating an implicit association of certain diseases with African Americans. These comprised not only diseases African Americans are genetically predisposed to, but also conditions and social behaviors with no biological association (e.g., obesity, drug abuse). Conclusions. We found implicit stereotyping among physicians; faces they never consciously saw altered performance. This suggests that diagnoses and treatment of African American patients may be biased, even in the absence of the practitioner's intent or awareness. PMID:22420815

  11. Barriers to Hospice Use among African Americans: A Systematic Review

    ERIC Educational Resources Information Center

    Washington, Karla T.; Bickel-Swenson, Denise; Stephens, Nathan

    2008-01-01

    The present review was undertaken to explore recent evidence in the professional literature pertaining to use of hospice services by African Americans. The article addresses the research methods that have been used to study African American hospice use, obstacles to African American participation in hospice that have been identified, and…

  12. Oral Cancer in African Americans: Addressing Health Disparities

    ERIC Educational Resources Information Center

    Dodd, Virginia J.; Watson, Jennifer M.; Choi, Youjin; Tomar, Scott L.; Logan, Henrietta L.

    2008-01-01

    Objectives: To explore factors underlying African Americans' perceptions of oral cancer and the oral cancer exam. Study findings were used to guide development of oral cancer messages designed to increase oral cancer exams among African Americans. Methods: Focus groups were conducted to understand African Americans' attitudes and expectations…

  13. A new non-overlapping concept to improve the Hybrid Particle Level Set method in multi-phase fluid flows

    NASA Astrophysics Data System (ADS)

    Archer, Philip J.; Bai, Wei

    2015-02-01

    A novel non-overlapping concept is augmented to the Hybrid Particle Level Set (HPLS) method to improve its accuracy and suitability for the modelling of multi-phase fluid flows. The concept addresses shortcomings in the reseeding algorithm, which maintains resolution of the surface at runtime. These shortcomings result in the misplacement of newly seeded particles in the opposite signed domain and necessitate a restriction on the distance that a particle can escape without deletion, which reduces the effectiveness of the method. The non-overlapping concept judges the suitability of potential new particles based on information already contained within the particle representation of the surface. By preventing the misplacement of particles it is possible to significantly relax the distance restriction thereby increasing the accuracy of the HPLS method in multi-phase flows. To demonstrate its robustness and efficiency, the concept is examined with a number of challenging test cases, including both level-set-only simulations and two-phase fluid flows.

  14. 3-dimensional throat region segmentation from MRI data based on Fourier interpolation and 3-dimensional level set methods.

    PubMed

    Campbell, Sean; Doshi, Trushali; Soraghan, John; Petropoulakis, Lykourgos; Di Caterina, Gaetano; Grose, Derek; MacKenzie, Kenneth

    2015-08-01

    A new algorithm for 3D throat region segmentation from magnetic resonance imaging (MRI) is presented. The proposed algorithm initially pre-processes the MRI data to increase the contrast between the throat region and its surrounding tissues and to reduce artifacts. Isotropic 3D volume is reconstructed using the Fourier interpolation. Furthermore, a cube encompassing the throat region is evolved using level set method to form a smooth 3D boundary of the throat region. The results of the proposed algorithm on real and synthetic MRI data are used to validate the robustness and accuracy of the algorithm. PMID:26736782

  15. General method to derive the relationship between two sets of Zernike coefficients corresponding to different aperture sizes

    PubMed Central

    Shu, Huazhong; Luo, Limin; Han, Guo-Niu; Coatrieux, Jean-Louis

    2006-01-01

    Zernike polynomials have been widely used to describe the aberrations in wave-front sensing of the eye. The Zernike coefficients are often computed under different aperture sizes. For the sake of comparison, the same aperture diameter is required. Since no standard aperture size is available for reporting the results, it is important to develop a technique for converting the Zernike coefficients obtained from one aperture size to another size. In this paper, by investigating the properties of Zernike polynomials, we propose a general method for establishing the relationship between two sets of Zernike coefficients computed with different aperture sizes. PMID:16835654

  16. Comparative analysis of cervical cytology and human papillomavirus genotyping by three different methods in a routine diagnostic setting.

    PubMed

    Padalko, Elizaveta; Ali-Risasi, Catherine; Mesmaekers, Stéphanie; Ryckaert, Inge; Van Renterghem, Lieve; Lambein, Kathleen; Bamelis, Mieke; De Mey, Anja; Sturtewagen, Yolande; Vastenavond, Hilde; Broeck, Davy Vanden; Weyers, Steven; Praet, Marleen

    2015-09-01

    Application of Bethesda guidelines on cervical cytology involves human papillomavirus (HPV) determinations on all ASC-US and ASC-H results. We compared HPV DNA results in view of the eventual development of a cervical intraepithelial neoplasia lesion determined either on cytology or histology. A total of 214 liquid-based cytology samples were analysed. Three different HPV DNA methods were applied: the Abbott RealTime High Risk HPV test, INNO-Lipa HPV Genotyping Extra and Full Spectrum PCR HPV Amplification and Detection/Genotyping System by Lab2Lab Diagnostic Service. A comparison of these three methods showed full concordance only for 49 samples (23%), and 27 (13%) of the samples were discordant in indicating the presence of the high-risk HPV type. Out of 214 patients, 88 were selected who presented with a cervical intraepithelial neoplasia or a VAIN lesion at follow-up cytology or histology. In this group, full concordance with HPV genotyping was present only in 19 (22%) follow-up samples. Nine (10%) follow-up samples showed discordant results for the presence of a high-risk genotype between the three genotyping methods tested either by negativity for high-risk HPV by one of the methods (n=6) or by failure to genotype HPV (n=2), or by a combination of both (n=1). Moreover, discordance for the detection of HPV16 or HPV18 was observed between the three HPV DNA genotyping methods used in 9 (10%) follow-up samples. In addition, the performance of genotyping methods on 20 external quality samples was assessed, showing discordant results for HPV16 and HPV18. Major differences were found in the genotyping results according to the HPV DNA method. Our findings highlight the importance of careful interpretation of data from studies using different HPV genotyping methods and underline the need for standardization by method validation in clinical laboratories, especially in the setting of primary HPV screening. PMID:25370681

  17. A level set method for image segmentation in the presence of intensity inhomogeneities with application to MRI.

    PubMed

    Li, Chunming; Huang, Rui; Ding, Zhaohua; Gatenby, J Chris; Metaxas, Dimitris N; Gore, John C

    2011-07-01

    Intensity inhomogeneity often occurs in real-world images, which presents a considerable challenge in image segmentation. The most widely used image segmentation algorithms are region-based and typically rely on the homogeneity of the image intensities in the regions of interest, which often fail to provide accurate segmentation results due to the intensity inhomogeneity. This paper proposes a novel region-based method for image segmentation, which is able to deal with intensity inhomogeneities in the segmentation. First, based on the model of images with intensity inhomogeneities, we derive a local intensity clustering property of the image intensities, and define a local clustering criterion function for the image intensities in a neighborhood of each point. This local clustering criterion function is then integrated with respect to the neighborhood center to give a global criterion of image segmentation. In a level set formulation, this criterion defines an energy in terms of the level set functions that represent a partition of the image domain and a bias field that accounts for the intensity inhomogeneity of the image. Therefore, by minimizing this energy, our method is able to simultaneously segment the image and estimate the bias field, and the estimated bias field can be used for intensity inhomogeneity correction (or bias correction). Our method has been validated on synthetic images and real images of various modalities, with desirable performance in the presence of intensity inhomogeneities. Experiments show that our method is more robust to initialization, faster and more accurate than the well-known piecewise smooth model. As an application, our method has been used for segmentation and bias correction of magnetic resonance (MR) images with promising results. PMID:21518662

  18. A three-dimensional coupled Nitsche and level set method for electrohydrodynamic potential flows in moving domains

    NASA Astrophysics Data System (ADS)

    Johansson, A.; Garzon, M.; Sethian, J. A.

    2016-03-01

    In this paper we present a new algorithm for computing three-dimensional electrohydrodynamic flow in moving domains which can undergo topological changes. We consider a non-viscous, irrotational, perfect conducting fluid and introduce a way to model the electrically charged flow with an embedded potential approach. To numerically solve the resulting system, we combine a level set method to track both the free boundary and the surface velocity potential with a Nitsche finite element method for solving the Laplace equations. This results in an algorithmic framework that does not require body-conforming meshes, works in three dimensions, and seamlessly tracks topological change. Assembling this coupled system requires care: while convergence and stability properties of Nitsche's methods have been well studied for static problems, they have rarely been considered for moving domains or for obtaining the gradients of the solution on the embedded boundary. We therefore investigate the performance of the symmetric and non-symmetric Nitsche formulations, as well as two different stabilization techniques. The global algorithm and in particular the coupling between the Nitsche solver and the level set method are also analyzed in detail. Finally we present numerical results for several time-dependent problems, each one designed to achieve a specific objective: (a) The oscillation of a perturbed sphere, which is used for convergence studies and the examination of the Nitsche methods; (b) The break-up of a two lobe droplet with axial symmetry, which tests the capability of the algorithm to go past flow singularities such as topological changes and preservation of an axi-symmetric flow, and compares results to previous axi-symmetric calculations; (c) The electrohydrodynamical deformation of a thin film and subsequent jet ejection, which will account for the presence of electrical forces in a non-axi-symmetric geometry.

  19. A probabilistic method to estimate the burden of maternal morbidity in resource-poor settings: preliminary development and evaluation

    PubMed Central

    2014-01-01

    Background Maternal morbidity is more common than maternal death, and population-based estimates of the burden of maternal morbidity could provide important indicators for monitoring trends, priority setting and evaluating the health impact of interventions. Methods based on lay reporting of obstetric events have been shown to lack specificity and there is a need for new approaches to measure the population burden of maternal morbidity. A computer-based probabilistic tool was developed to estimate the likelihood of maternal morbidity and its causes based on self-reported symptoms and pregnancy/delivery experiences. Development involved the use of training datasets of signs, symptoms and causes of morbidity from 1734 facility-based deliveries in Benin and Burkina Faso, as well as expert review. Preliminary evaluation of the method compared the burden of maternal morbidity and specific causes from the probabilistic tool with clinical classifications of 489 recently-delivered women from Benin, Bangladesh and India. Results Using training datasets, it was possible to create a probabilistic tool that handled uncertainty of women’s self reports of pregnancy and delivery experiences in a unique way to estimate population-level burdens of maternal morbidity and specific causes that compared well with clinical classifications of the same data. When applied to test datasets, the method overestimated the burden of morbidity compared with clinical review, although possible conceptual and methodological reasons for this were identified. Conclusion The probabilistic method shows promise and may offer opportunities for standardised measurement of maternal morbidity that allows for the uncertainty of women’s self-reported symptoms in retrospective interviews. However, important discrepancies with clinical classifications were observed and the method requires further development, refinement and evaluation in a range of settings. PMID:24620784

  20. A Scoping Review of Behavioral Weight Management Interventions in Overweight/Obese African American Females.

    PubMed

    Sutton, Suzanne M; Magwood, Gayenell S; Jenkins, Carolyn H; Nemeth, Lynne S

    2016-08-01

    African American females are adversely affected by overweight and obesity and accompanying physical, psychosocial, and economic consequences. Behavioral weight management interventions are less effective in addressing the needs of overweight and obese African American females. The objective of this scoping review was to explore weight management research in this population to identify key concepts, gaps in the literature, and implications for future research. Analyses revealed a broad array in purpose, theoretical frameworks, settings, study designs, interventions, intervention strategies, and outcome variables, making comparison difficult. Many of the articles included in this review did not provide a rich description of methods, which hinder their use in the development of future studies. Consistent application of a combined theory may address the gaps identified in this review by providing a reliable method for assessing needs, developing interventions, and evaluating the effectiveness and fidelity of behavioral weight management interventions in overweight and obese African American females. PMID:26927607

  1. Does counselling improve uptake of long-term and permanent contraceptive methods in a high HIV-prevalence setting?

    PubMed Central

    Dudley, Lilian; Makumucha, Courage; Dlamini, Phatisizwe; Moyo, Sihle; Bhembe, Sibongiseni

    2015-01-01

    Abstract Background Studies have shown a reduced uptake of contraceptive methods in HIV-positive women of childbearing age, mainly because of unmet needs that may be a result of poor promotion of available methods of contraception, especially long-term and permanent methods (LTPM). Aim To compare the uptake of contraceptive methods, and particularly LTPM, by HIV-positive and HIV-negative post-partum mothers, and to assess the effects of counselling on contraceptive choices. Setting Three government district hospitals in Swaziland. Methods Interviews were conducted using a structured questionnaire, before and after counselling HIV-negative and HIV-positive post-partum women in LTPM use, unintended pregnancy rates, future fertility and reasons for contraceptive choices. Results A total of 711 women, of whom half were HIV-positive, participated in the study. Most (72.3% HIV-negative and 84% HIV-positive) were on modern methods of contraception, with the majority using 2-monthly and 3-monthly injectables. Intended use of any contraceptive increased to 99% after counselling. LTPM use was 7.0% in HIV-negative mothers and 15.3% in HIV-positive mothers before counselling, compared with 41.3% and 42.4% in HIV-negative and HIV-positive mothers, respectively, after counselling. Pregnancy intentions and counselling on future fertility were significantly associated with current use of contraception, whilst current LTPM use and level of education were significantly associated with LTPM post-counselling. Conclusion Counselling on all methods including LTPM reduced unmet needs in contraception in HIV-positive and HIV-negative mothers and could improve contraceptive uptake and reduce unintended pregnancies. Health workers do not always remember to include LTPM when they counsel clients, which could result in a low uptake of these methods. Further experimental studies should be conducted to validate these results. PMID:26842525

  2. AN ACCURATE NEW METHOD OF CALCULATING ABSOLUTE MAGNITUDES AND K-CORRECTIONS APPLIED TO THE SLOAN FILTER SET

    SciTech Connect

    Beare, Richard; Brown, Michael J. I.; Pimbblet, Kevin

    2014-12-20

    We describe an accurate new method for determining absolute magnitudes, and hence also K-corrections, that is simpler than most previous methods, being based on a quadratic function of just one suitably chosen observed color. The method relies on the extensive and accurate new set of 129 empirical galaxy template spectral energy distributions from Brown et al. A key advantage of our method is that we can reliably estimate random errors in computed absolute magnitudes due to galaxy diversity, photometric error and redshift error. We derive K-corrections for the five Sloan Digital Sky Survey filters and provide parameter tables for use by the astronomical community. Using the New York Value-Added Galaxy Catalog, we compare our K-corrections with those from kcorrect. Our K-corrections produce absolute magnitudes that are generally in good agreement with kcorrect. Absolute griz magnitudes differ by less than 0.02 mag and those in the u band by ∼0.04 mag. The evolution of rest-frame colors as a function of redshift is better behaved using our method, with relatively few galaxies being assigned anomalously red colors and a tight red sequence being observed across the whole 0.0 < z < 0.5 redshift range.

  3. Testing Allele Transmission of an SNP Set Using a Family-Based Generalized Genetic Random Field Method.

    PubMed

    Li, Ming; Li, Jingyun; He, Zihuai; Lu, Qing; Witte, John S; Macleod, Stewart L; Hobbs, Charlotte A; Cleves, Mario A

    2016-05-01

    Family-based association studies are commonly used in genetic research because they can be robust to population stratification (PS). Recent advances in high-throughput genotyping technologies have produced a massive amount of genomic data in family-based studies. However, current family-based association tests are mainly focused on evaluating individual variants one at a time. In this article, we introduce a family-based generalized genetic random field (FB-GGRF) method to test the joint association between a set of autosomal SNPs (i.e., single-nucleotide polymorphisms) and disease phenotypes. The proposed method is a natural extension of a recently developed GGRF method for population-based case-control studies. It models offspring genotypes conditional on parental genotypes, and, thus, is robust to PS. Through simulations, we presented that under various disease scenarios the FB-GGRF has improved power over a commonly used family-based sequence kernel association test (FB-SKAT). Further, similar to GGRF, the proposed FB-GGRF method is asymptotically well-behaved, and does not require empirical adjustment of the type I error rates. We illustrate the proposed method using a study of congenital heart defects with family trios from the National Birth Defects Prevention Study (NBDPS). PMID:27061818

  4. Introduction of a fully relativistic capable basis set in the ab initio orthogonalized linear combination of atomic orbitals method

    NASA Astrophysics Data System (ADS)

    Thomas, Patrick Ryan

    Large simulation cell sizes, relativistic effects, and the need to correctly model excited state properties are major impediments to the accurate prediction of the optical properties of candidate materials for solid-state laser crystal and luminescent applications. To overcome these challenges, new methods must be created to improve the electron orbital wavefunction and interactions. In this work, a method has been developed to create new analytical four-component, fully-relativistic and single-component scalar relativistic descriptions of the atomic orbital wave functions from Grasp2K numerically represented atomic orbitals. In addition, adapted theory for the calculation of the relativistic kinetic energy contribution to Hamiltonian which bypasses directly solving the Dirac equation has been explicated. The orbital description improvements are tested against YAG, YBCO, SnO2 and BiF3. The improvements to the basis set reflect an improvement in both computational speed and accuracy.

  5. Evaluation of two sets of immunohistochemical and Western blot confirmatory methods in the detection of typical and atypical BSE cases

    PubMed Central

    2011-01-01

    Background Three distinct forms of bovine spongiform encephalopathy (BSE), defined as classical (C-), low (L-) or high (H-) type, have been detected through ongoing active and passive surveillance systems for the disease. The aim of the present study was to compare the ability of two sets of immunohistochemical (IHC) and Western blot (WB) BSE confirmatory protocols to detect C- and atypical (L- and H-type) BSE forms. Obex samples from cases of United States and Italian C-type BSE, a U.S. H-type and an Italian L-type BSE case were tested in parallel using the two IHC sets and WB methods. Results The two IHC techniques proved equivalent in identifying and differentiating between C-type, L-type and H-type BSE. The IHC protocols appeared consistent in the identification of PrPSc distribution and deposition patterns in relation to the BSE type examined. Both IHC methods evidenced three distinct PrPSc phenotypes for each type of BSE: prevailing granular and linear tracts pattern in the C-type; intraglial and intraneuronal deposits in the H-type; plaques in the L-type. Also, the two techniques gave comparable results for PrPSc staining intensity on the C- and L-type BSE samples, whereas a higher amount of intraglial and intraneuronal PrPSc deposition on the H-type BSE case was revealed by the method based on a stronger demasking step. Both WB methods were consistent in identifying classical and atypical BSE forms and in differentiating the specific PrPSc molecular weight and glycoform ratios of each form. Conclusions The study showed that the IHC and WB BSE confirmatory methods were equally able to recognize C-, L- and H-type BSE forms and to discriminate between their different immunohistochemical and molecular phenotypes. Of note is that for the first time one of the two sets of BSE confirmatory protocols proved effective in identifying the L-type BSE form. This finding helps to validate the suitability of the BSE confirmatory tests for BSE surveillance currently in

  6. LV wall segmentation using the variational level set method (LSM) with additional shape constraint for oedema quantification

    NASA Astrophysics Data System (ADS)

    Kadir, K.; Gao, H.; Payne, A.; Soraghan, J.; Berry, C.

    2012-10-01

    In this paper an automatic algorithm for the left ventricle (LV) wall segmentation and oedema quantification from T2-weighted cardiac magnetic resonance (CMR) images is presented. The extent of myocardial oedema delineates the ischaemic area-at-risk (AAR) after myocardial infarction (MI). Since AAR can be used to estimate the amount of salvageable myocardial post-MI, oedema imaging has potential clinical utility in the management of acute MI patients. This paper presents a new scheme based on the variational level set method (LSM) with additional shape constraint for the segmentation of T2-weighted CMR image. In our approach, shape information of the myocardial wall is utilized to introduce a shape feature of the myocardial wall into the variational level set formulation. The performance of the method is tested using real CMR images (12 patients) and the results of the automatic system are compared to manual segmentation. The mean perpendicular distances between the automatic and manual LV wall boundaries are in the range of 1-2 mm. Bland-Altman analysis on LV wall area indicates there is no consistent bias as a function of LV wall area, with a mean bias of -121 mm2 between individual investigator one (IV1) and LSM, and -122 mm2 between individual investigator two (IV2) and LSM when compared to two investigators. Furthermore, the oedema quantification demonstrates good correlation when compared to an expert with an average error of 9.3% for 69 slices of short axis CMR image from 12 patients.

  7. Mask pattern recovery by level set method based inverse inspection technology (IIT) and its application on defect auto disposition

    NASA Astrophysics Data System (ADS)

    Park, Jin-Hyung; Chung, Paul D. H.; Jeon, Chan-Uk; Cho, Han Ku; Pang, Linyong; Peng, Danping; Tolani, Vikram; Cecil, Tom; Kim, David; Baik, KiHo

    2009-10-01

    At the most advanced technology nodes, such as 32nm and 22nm, aggressive OPC and Sub-Resolution Assist Features (SRAFs) are required. However, their use results in significantly increased mask complexity, making mask defect disposition more challenging than ever. This paper describes how mask patterns can first be recovered from the inspection images by applying patented algorithms using Level Set Methods. The mask pattern recovery step is then followed by aerial/wafer image simulation, the results of which can be plugged into an automated mask defect disposition system based on aerial/wafer image. The disposition criteria are primarily based on wafer-plane CD variance. The system also connects to a post-OPC lithography verification tool that can provide gauges and CD specs, thereby enabling them to be used in mask defect disposition as well. Results on both programmed defects and production defects collected at Samsung mask shop are presented to show the accuracy and consistency of using the Level Set Methods and aerial/wafer image based automated mask disposition.

  8. Multiplex PCR for the detection of African cassava mosaic virus and East African cassava mosaic Cameroon virus in cassava.

    PubMed

    Alabi, Olufemi J; Kumar, P Lava; Naidu, Rayapati A

    2008-12-01

    A multiplex PCR was developed for simultaneous detection of African cassava mosaic virus (ACMV) and East African cassava mosaic Cameroon virus (EACMCV) in cassava affected with cassava mosaic disease (CMD). One set of three primers consisting of an upstream primer common for both viruses and two down stream virus-specific primers were designed for simultaneous amplification of 368 base pair (bp) and 650 bp DNA fragments specific to the replicase gene of ACMV and EACMCV, respectively. Similarly, a second set of three primers were designed for simultaneous amplification of 540 bp and 655 bp fragments specific to the coat protein gene of EACMCV and ACMV, respectively. Primers that can amplify a 171 bp fragment of the large subunit of ribulose bisphosphate carboxylase oxygenase L were included as an internal control in these assays to determine the reliability of multiplex PCR. A simplified, cost-effective and rapid sample preparation method was adapted in place of the conventional plant DNA extraction procedure for multiplex PCR detection of ACMV and EACMCV. The method was validated using CMD-infected cassava samples obtained from farmers' fields in Nigeria. The multiplex PCR is useful for reliable assessment of the prevalence of CMBs in epidemiological studies and for crop improvement and phytosanitary programs in African countries. PMID:18789974

  9. Comparing hepatic 2D and 3D magnetic resonance elastography methods in a clinical setting – Initial experiences

    PubMed Central

    Forsgren, Mikael F.; Norén, Bengt; Kihlberg, Johan; Dahlqvist Leinhard, Olof; Kechagias, Stergios; Lundberg, Peter

    2015-01-01

    Purpose Continuous monitoring of liver fibrosis progression in patients is not feasible with the current diagnostic golden standard (needle biopsy). Recently, magnetic resonance elastography (MRE) has emerged as a promising method for such continuous monitoring. Since there are different MRE methods that could be used in a clinical setting there is a need to investigate whether measurements produced by these MRE methods are comparable. Hence, the purpose of this pilot study was to evaluate whether the measurements of the viscoelastic properties produced by 2D (stiffness) and 3D (elasticity and ‘Gabs,Elastic’) MRE are comparable. Materials and methods Seven patients with diffuse or suspect diffuse liver disease were examined in the same day with the two MRE methods. 2D MRE was performed using an acoustic passive transducer, with a 1.5 T GE 450 W MR system. 3D MRE was performed using an electromagnetic active transducer, with a 1.5 T Philips Achieva MR system. Finally, mean viscoelastic values were extracted from the same anatomical region for both methods by an experienced radiologist. Results Stiffness correlated well with the elasticity, R2 = 0.96 (P < 0.001; slope = 1.08, intercept = 0.61 kPa), as well as with ‘Gabs,Elastic’ R2 = 0.96 (P < 0.001; slope = 0.95, intercept = 0.28 kPa). Conclusion This pilot study shows that different MRE methods can produce comparable measurements of the viscoelastic properties of the liver. The existence of such comparable measurements is important, both from a clinical as well as a research perspective, since it allows for equipment-independent monitoring of disease progression. PMID:26937438

  10. Rationale, Design and Methods of the Ecological Study of Sexual Behaviors and HIV/STI among African American Men Who Have Sex with Men in the Southeastern United States (The MARI Study)

    PubMed Central

    Hickson, DeMarc A.; Truong, Nhan L.; Smith-Bankhead, Neena; Sturdevant, Nikendrick; Duncan, Dustin T.; Schnorr, Jordan; Gipson, June A.; Mena, Leandro A.

    2015-01-01

    Background This paper describes the rationale, design, and methodology of the Ecological Study of Sexual Behaviors and HIV/STI among African American Men Who Have Sex with Men (MSM) in the Southeastern United States (U.S.; known locally simply as the MARI Study). Methods Participants are African American MSM aged 18 years and older residing in the deep South. Results Between 2013 and 2015, 800 African American MSM recruited from two study sites (Jackson, MS and Atlanta, GA) will undergo a 1.5-hour examination to obtain anthropometric and blood pressure measures as well as to undergo testing for sexually transmitted infections (STI), including HIV. Intrapersonal, interpersonal, and environmental factors are assessed by audio computer-assisted self-interview survey. Primary outcomes include sexual risk behaviors (e.g., condomless anal sex) and prevalent STIs (HIV, syphilis, gonorrhea, and Chlamydia). Conclusion The MARI Study will typify the HIV environmental 'riskscape' and provide empirical evidence into novel ecological correlates of HIV risk among African American MSM in the deep South, a population most heavily impacted by HIV. The study's anticipated findings will be of interest to a broad audience and lead to more informed prevention efforts, including effective policies and interventions, that achieve the goals of the updated 2020 U.S. National HIV/AIDS Strategy. PMID:26700018

  11. A hybrid smoothed extended finite element/level set method for modeling equilibrium shapes of nano-inhomogeneities

    NASA Astrophysics Data System (ADS)

    Zhao, Xujun; Bordas, Stéphane P. A.; Qu, Jianmin

    2013-12-01

    Interfacial energy plays an important role in equilibrium morphologies of nanosized microstructures of solid materials due to the high interface-to-volume ratio, and can no longer be neglected as it does in conventional mechanics analysis. When designing nanodevices and to understand the behavior of materials at the nano-scale, this interfacial energy must therefore be taken into account. The present work develops an effective numerical approach by means of a hybrid smoothed extended finite element/level set method to model nanoscale inhomogeneities with interfacial energy effect, in which the finite element mesh can be completely independent of the interface geometry. The Gurtin-Murdoch surface elasticity model is used to account for the interface stress effect and the Wachspress interpolants are used for the first time to construct the shape functions in the smoothed extended finite element method. Selected numerical results are presented to study the accuracy and efficiency of the proposed method as well as the equilibrium shapes of misfit particles in elastic solids. The presented results compare very well with those obtained from theoretical solutions and experimental observations, and the computational efficiency of the method is shown to be superior to that of its most advanced competitor.

  12. Intensity of play behavior as a potential measure of welfare: A novel method for quantifying the integrated intensity of behavior in African elephants.

    PubMed

    Vicino, Greg A; Marcacci, Emily S

    2015-01-01

    To the authors' knowledge there is currently no discrete index to measure the integrated intensity of a play bout in mammals, despite the potential for using intensity and duration of play bouts as a measure of physical activity and welfare. This study was developed to test an equation that quantified the intensity and duration of play bouts in a particularly gregarious mammal, African elephants (Loxodonta africana) housed at the San Diego Zoo Safari Park in Escondido, CA. To quantify these behaviors, we created a scale of intensity and a subsequent equation that produces an index value, giving each unique bout a score. A compilation of these scores provides a range of intensity of play behavior that is a representative value for that particular herd at that point in time, and thus a database to which later bouts can be compared. It can be argued that play behavior is an indicator of positive welfare, and if quantifiable, it is our belief that it can be used as an additional measure of positive welfare in zoo housed animals. Here we present the methods and technique used to calculate a standardized Integrated Play Index (IPI) that has potential for use in other socially living species that are known to exhibit play behavior. PMID:26251201

  13. “I Just Can’t Do It Anymore” Patterns of Physical Activity and Cardiac Rehabilitation in African Americans with Heart Failure: A Mixed Method Study

    PubMed Central

    McCarthy, Margaret; Katz, Stuart D.; Schipper, Judith; Dickson, Victoria Vaughan

    2015-01-01

    Physical activity and cardiac rehabilitation (CR) are components of heart failure (HF) self-care. The aims of this study were to describe patterns of physical activity in African Americans (n = 30) with HF and to explore experience in CR. This was a mixed method, concurrent nested, predominantly qualitative study. Qualitative data were collected via interviews exploring typical physical activity, and CR experience. It was augmented by quantitative data measuring HF severity, self-care, functional capacity and depressive symptoms. Mean age was 60 ± 15 years; 65% were New York Heart Association (NYHA) class III HF. Forty-three percent reported that they did less than 30 min of exercise in the past week; 23% were told “nothing” about exercise by their provider, and 53% were told to do “minimal exercise”. A measure of functional capacity indicated the ability to do moderate activity. Two related themes stemmed from the narratives describing current physical activity: “given up” and “still trying”. Six participants recalled referral to CR with one person participating. There was high concordance between qualitative and quantitative data, and evidence that depression may play a role in low levels of physical activity. Findings highlight the need for strategies to increase adherence to current physical activity guidelines in this older minority population with HF. PMID:27417807

  14. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  15. Extending the African instrumental record to the early 19th century

    SciTech Connect

    Nicholson, S.E.

    1997-11-01

    This paper describes progress toward the production of a data set that extends the African climate record back to the beginning of the 19th century. Qualitative documentary evidence, lake-level fluctuations and other proxy indicators are combined with historical rainfall records to produce regional time series. The data set has relatively high temporal and spatial resolution. The conceptualization is based on a climatic regionalization produced using modern data and an anomaly method in previous historical reconstructions. The data set provides information for some 100 regions with a 1 to 5 year resolution for most of the nineteenth century. Three to five quantitative classes of rainfall are utilized in the data set. Here, the available information to produce this record is summarized. The methodology utilized to combine proxy data and observations to produce a quantitative rainfall data set is described. This historical data set is compared with actual rainfall records for select regions where both are available. This comparison indicates the reliability of the proxy African data set. An analysis of the historical record indicates that the main characteristics of rainfall variability evident in the modern African record are also apparent in the 19th century record. 5 figs.

  16. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  17. The Objective Borderline Method (OBM): A Probability-Based Model for Setting up an Objective Pass/Fail Cut-Off Score in Medical Programme Assessments

    ERIC Educational Resources Information Center

    Shulruf, Boaz; Turner, Rolf; Poole, Phillippa; Wilkinson, Tim

    2013-01-01

    The decision to pass or fail a medical student is a "high stakes" one. The aim of this study is to introduce and demonstrate the feasibility and practicality of a new objective standard-setting method for determining the pass/fail cut-off score from borderline grades. Three methods for setting up pass/fail cut-off scores were compared: the…

  18. A Bayesian method to mine spatial data sets to evaluate the vulnerability of human beings to catastrophic risk.

    PubMed

    Li, Lianfa; Wang, Jinfeng; Leung, Hareton; Zhao, Sisi

    2012-06-01

    Vulnerability of human beings exposed to a catastrophic disaster is affected by multiple factors that include hazard intensity, environment, and individual characteristics. The traditional approach to vulnerability assessment, based on the aggregate-area method and unsupervised learning, cannot incorporate spatial information; thus, vulnerability can be only roughly assessed. In this article, we propose Bayesian network (BN) and spatial analysis techniques to mine spatial data sets to evaluate the vulnerability of human beings. In our approach, spatial analysis is leveraged to preprocess the data; for example, kernel density analysis (KDA) and accumulative road cost surface modeling (ARCSM) are employed to quantify the influence of geofeatures on vulnerability and relate such influence to spatial distance. The knowledge- and data-based BN provides a consistent platform to integrate a variety of factors, including those extracted by KDA and ARCSM to model vulnerability uncertainty. We also consider the model's uncertainty and use the Bayesian model average and Occam's Window to average the multiple models obtained by our approach to robust prediction of the risk and vulnerability. We compare our approach with other probabilistic models in the case study of seismic risk and conclude that our approach is a good means to mining spatial data sets for evaluating vulnerability. PMID:22404550

  19. Optimization of Physical Working Environment Setting to Improve Productivity and Minimize Error by Taguchi and VIKOR Methods

    NASA Astrophysics Data System (ADS)

    Ilma Rahmillah, Fety

    2016-01-01

    The working environment is one factor that has contribution to the worker's performance, especially for continuous and monotonous works. L9 Taguchi design experiment for inner array is used to design the experiment which was carried out in laboratory whereas L4 is for outer array. Four control variables with three levels of each are used to get the optimal combination of working environment setting. Four responses are also measured to know the effect of four control factors. Results shown that by using ANOVA, the effect of illumination, temperature, and instrumental music to the number of ouput, number of error, and rating perceived discomfort is significant with the total variance explained of 54,67%, 60,67%, and 75,22% respectively. By using VIKOR method, it yields the optimal combination of experiment 66 with the setting condition of A3-B2-C1-D3. The illumination is 325-350 lux, temperature is 240-260C, fast category of instrumental music, and 70-80 dB for intensity of the music being played.

  20. Optical flow 3D segmentation and interpretation: a variational method with active curve evolution and level sets.

    PubMed

    Mitiche, Amar; Sekkati, Hicham

    2006-11-01

    This study investigates a variational, active curve evolution method for dense three-dimentional (3D) segmentation and interpretation of optical flow in an image sequence of a scene containing moving rigid objects viewed by a possibly moving camera. This method jointly performs 3D motion segmentation, 3D interpretation (recovery of 3D structure and motion), and optical flow estimation. The objective functional contains two data terms for each segmentation region, one based on the motion-only equation which relates the essential parameters of 3D rigid body motion to optical flow, and the other on the Horn and Schunck optical flow constraint. It also contains two regularization terms for each region, one for optical flow, the other for the region boundary. The necessary conditions for a minimum of the functional result in concurrent 3D-motion segmentation, by active curve evolution via level sets, and linear estimation of each region essential parameters and optical flow. Subsequently, the screw of 3D motion and regularized relative depth are recovered analytically for each region from the estimated essential parameters and optical flow. Examples are provided which verify the method and its implementation. PMID:17063686

  1. hp discontinuous Galerkin methods for the vertical extent of the water column in coastal settings part I: Barotropic forcing

    NASA Astrophysics Data System (ADS)

    Conroy, Colton J.; Kubatko, Ethan J.

    2016-01-01

    In this article, we present novel, high-order, discontinuous Galerkin (DG) methods for the vertical extent of the water column in coastal settings. We examine the shallow water equations (SWE) in the context of DG spatial discretizations coupled with explicit Runge-Kutta (RK) time stepping. All the primary variables, including the free surface elevation, are discretized using discontinuous polynomial spaces of arbitrary order. The difficulty of mismatched lateral boundary faces that accompanies the use of a discontinuous free surface is overcome through the use of a so-called sigma-coordinate system in the vertical, which transforms the bottom boundary and free surface into coordinate surfaces. We develop high-order methods for the SWE that exhibit optimal orders of convergence for all the primary variables via two distinct paths: the first involves the use of a convolution kernel made up of B-splines to filter out errors in the DG discretization of the surface elevation and the corresponding pressure flux. The second involves a method that evaluates the discrete depth-integrated velocity exactly, eliminating the need to solve the depth-integrated momentum equation altogether. The result is a simple and efficient high-order scheme that can be extended to the full three-dimensional SWE.

  2. Strong postcranial size dimorphism in Australopithecus afarensis: results from two new resampling methods for multivariate data sets with missing data.

    PubMed

    Gordon, Adam D; Green, David J; Richmond, Brian G

    2008-03-01

    There is considerable debate over the level of size dimorphism and inferred social behavior of Australopithecus afarensis. Most previous studies have analyzed size variation in single variables or multiple variables drawn from single elements. These approaches suffer from small sample sizes, underscoring the need for new techniques that incorporate measurements from multiple unassociated elements, reducing the influence of random sampling on size variation in fossil samples. One such technique, the template method, has recently been proposed but is limited to samples with a template specimen and is sensitive to a number of assumptions. Here we present two new resampling methods that do not require a template specimen, allow measurements from multiple unassociated elements to be included in a single analysis, and allow for significance tests between comparative and fossil multivariate data sets with missing data. Using these new methods, multivariate postcranial size dimorphism is measured using eight measurements of the femur, tibia, humerus, and radius in samples of A. afarensis, modern humans, chimpanzees, gorillas, and orangutans. Postcranial dimorphism in A. afarensis is similar to that of gorillas and orangutans, and significantly greater than in modern humans and chimpanzees. Because studies in living primates have examined the association of behavior with dimorphism in body mass and craniodental measurements, not postcrania, relationships between postcranial dimorphism and social behavior must be established to make robust behavioral inferences for A. afarensis. However, the results of this and past studies strongly suggest behavioral and mating strategies differed between A. afarensis and modern humans. PMID:18044693

  3. Chemomechanical caries removal method versus mechanical caries removal methods in clinical and community-based setting: A comparative in vivo study

    PubMed Central

    Kumar, K. V. K. Santosh; Prasad, M. Ghanashyam; Sandeep, R. Venkata; Reddy, S. Pavani; Divya, D.; Pratyusha, K.

    2016-01-01

    Objective: To compare the effectiveness of various caries removal techniques in mandibular primary molars using Smart Burs, atraumatic restorative technique (ART) (mechanical caries removal) and Carie-care (chemomechanical caries removal [CMCR]) among primary school children in clinical and community-based settings. Materials and Methods: A total of 80 carious primary mandibular molars were selected for the study from the dental clinic and community. They were equally assigned to four groups according to caries removal technique and also by the operating site. In Group 1, caries was removed using Carie-care in the dental clinic and in Group 2, with Smart Burs in the dental clinic. In Group 3, caries was removed using Carie-care in the field and in Group 4, with the ART in the field. The time taken for caries removal, the efficacy of caries removal and patient acceptance were evaluated with different caries removal techniques. Statistical Analysis: The obtained data were subjected to statistical analysis by ANOVA test. Results: In clinical settings, Carie-care was time-consuming but was more efficient with increased acceptance than Smart Burs and the result was found to be significant statistically (P < 0.05). In community-based settings, Carie-care was more efficient, less time consuming, and showed an increased acceptance when compared to atraumatic restorative treatment and the result was found to be significant statistically (P < 0.05). Conclusions: The CMCR technique was superior to the mechanical caries removal technique in primary teeth among school children in terms of time, efficacy, and acceptance in both clinical- and community-based settings. PMID:27403059

  4. Calculation of contact angles at triple phase boundary in solid oxide fuel cell anode using the level set method

    SciTech Connect

    Sun, Xiaojun; Hasegawa, Yosuke; Kohno, Haruhiko; Jiao, Zhenjun; Hayakawa, Koji; Okita, Kohei; Shikazono, Naoki

    2014-10-15

    A level set method is applied to characterize the three dimensional structures of nickel, yttria stabilized zirconia and pore phases in solid oxide fuel cell anode reconstructed by focused ion beam-scanning electron microscope. A numerical algorithm is developed to evaluate the contact angles at the triple phase boundary based on interfacial normal vectors which can be calculated from the signed distance functions defined for each of the three phases. Furthermore, surface tension force is estimated from the contact angles by assuming the interfacial force balance at the triple phase boundary. The average contact angle values of nickel, yttria stabilized zirconia and pore are found to be 143°–156°, 83°–138° and 82°–123°, respectively. The mean contact angles remained nearly unchanged after 100 hour operation. However, the contact angles just after reduction are different for the cells with different sintering temperatures. In addition, standard deviations of the contact angles are very large especially for yttria stabilized zirconia and pore phases. The calculated surface tension forces from mean contact angles were close to the experimental values found in the literature. Slight increase of surface tensions of nickel/pore and nickel/yttria stabilized zirconia were observed after operation. Present data are expected to be used not only for the understanding of the degradation mechanism, but also for the quantitative prediction of the microstructural temporal evolution of solid oxide fuel cell anode. - Highlights: • A level set method is applied to characterize the 3D structures of SOFC anode. • A numerical algorithm is developed to evaluate the contact angles at the TPB. • Surface tension force is estimated from the contact angles. • The average contact angle values are found to be 143o-156o, 83o-138o and 82o-123o. • Present data are expected to understand degradation and predict evolution of SOFC.

  5. Implementation of a low-budget, lifestyle-improvement method in an ordinary primary healthcare setting: a stepwise intervention study

    PubMed Central

    Blomstrand, Ann; Ariai, Nashmil; Baar, Ann-Christine; Finbom-Forsgren, Britt-Marie; Thorn, Jörgen; Björkelund, Cecilia

    2012-01-01

    Objective To evaluate, in an ordinary primary healthcare setting, the effects of a screening questionnaire and a self-administered health profile dealing with special reference to the involvement of motivated individuals in need of lifestyle changes. Design Intervention study in a naturalistic context, using a screening questionnaire offered to consecutive patients, followed by a self-administered health profile and a health dialogue. Setting Hisingen primary healthcare area (130 033 inhabitants), Gothenburg, Sweden. Participants Men and women aged between 18 and 79, visiting any of the eight public primary healthcare centres (PCC) during an 8-month period, were presented with a screening questionnaire and, were offered, a health profile, a plasma glucose (p-glucose), blood pressure check and a health dialogue. Main outcome measures Motivation level, negative lifestyle factors in screening questionnaire and intraindividual changes in blood pressure, p-glucose, body mass index (BMI) and lifestyle factors between baseline and 1-year follow-up. Results Subjects with less favourable lifestyle and higher motivation chose to participate. A higher percentage of presumptive participants reported a less favourable lifestyle. The presumptive participants also indicated higher motivation. Participants showed more readiness to initiate lifestyle changes compared to non-participants (p<0.001). At 1-year follow-up significant reductions in BMI, waist circumference, waist–hip ratio (WHR), blood pressure and p-glucose were observed. Conclusions The results indicate that the method is on target and applicable to motivated individuals with a ‘risk profile’. A pedagogical model including a self-administered health-profile and a health dialogue, combined with emphasising the individual's own resources, seems to be a feasible method for effective preventive work in primary healthcare. PMID:22874629

  6. New data on African health professionals abroad

    PubMed Central

    Clemens, Michael A; Pettersson, Gunilla

    2008-01-01

    Background The migration of doctors and nurses from Africa to developed countries has raised fears of an African medical brain drain. But empirical research on the causes and effects of the phenomenon has been hampered by a lack of systematic data on the extent of African health workers' international movements. Methods We use destination-country census data to estimate the number of African-born doctors and professional nurses working abroad in a developed country circa 2000, and compare this to the stocks of these workers in each country of origin. Results Approximately 65,000 African-born physicians and 70,000 African-born professional nurses were working overseas in a developed country in the year 2000. This represents about one fifth of African-born physicians in the world, and about one tenth of African-born professional nurses. The fraction of health professionals abroad varies enormously across African countries, from 1% to over 70% according to the occupation and country. Conclusion These numbers are the first standardized, systematic, occupation-specific measure of skilled professionals working in developed countries and born in a large number of developing countries. PMID:18186916

  7. Association between Food Insecurity and Procurement Methods among People Living with HIV in a High Resource Setting

    PubMed Central

    Anema, Aranka; Fielden, Sarah J.; Shurgold, Susan; Ding, Erin; Messina, Jennifer; Jones, Jennifer E.; Chittock, Brian; Monteith, Ken; Globerman, Jason; Rourke, Sean B.; Hogg, Robert S.

    2016-01-01

    Objective People living with HIV in high-resource settings suffer severe levels of food insecurity; however, limited evidence exists regarding dietary intake and sub-components that characterize food insecurity (i.e. food quantity, quality, safety or procurement) in this population. We examined the prevalence and characteristics of food insecurity among people living with HIV across British Columbia, Canada. Design This cross-sectional analysis was conducted within a national community-based research initiative. Methods Food security was measured using the Health Canada Household Food Security Scale Module. Logistic regression was used to determine key independent predictors of food insecurity, controlling for potential confounders. Results Of 262 participants, 192 (73%) reported food insecurity. Sub-components associated with food insecurity in bivariate analysis included: < RDI consumption of protein (p = 0.046); being sick from spoiled/unsafe food in the past six months (p = 0.010); and procurement of food using non-traditional methods (p <0.05). In multivariable analyses, factors significantly associated with food insecurity included: procurement of food using non-traditional methods [AOR = 11.11, 95% CI: 4.79–25.68, p = <0.001]; younger age [AOR = 0.92, 95% CI: 0.86–0.96, p = <0.001]; unstable housing [AOR = 4.46, 95% CI: 1.15–17.36, p = 0.031]; household gross annual income [AOR = 4.49, 95% CI: 1.74–11.60, p = 0.002]; and symptoms of depression [AOR = 2.73, 95% CI: 1.25–5.96, p = 0.012]. Conclusions Food insecurity among people living with HIV in British Columbia is characterized by poor dietary quality and food procurement methods. Notably, participants who reported procuring in non-traditional manners were over 10 times more likely to be food insecure. These findings suggest a need for tailored food security and social support interventions in this setting. PMID:27487041

  8. Field, geochemistry and Sr-Nd isotopes of the Pan-African granitoids from the Tifnoute Valley (Sirwa, Anti-Atlas, Morocco): a post-collisional event in a metacratonic setting

    NASA Astrophysics Data System (ADS)

    Toummite, A.; Liegeois, J. P.; Gasquet, D.; Bruguier, O.; Beraaouz, E. H.; Ikenne, M.

    2013-10-01

    In the Tifnoute Valley, three plutonic units have been defined: the Askaoun intrusion, the Imourkhssen intrusion and the Ougougane group of small intrusions. They are made of quartz diorite, granodiorite and granite and all contain abundant mafic microgranular enclaves (MME). The Askaoun granodiorite and the Imourkhssen granite have been dated by LA-ICP-MS on zircon at 558 ± 2 Ma and 561 ± 3 Ma, respectively. These granitic intrusions are subcontemporaneous to the widespread volcanic and volcano-detrital rocks from the Ouarzazate Group (580-545 Ma), marking the post-collisional transtensional period in the Anti-Atlas and which evolved towards alkaline and tholeiitic lavas in minor volume at the beginning of the Cambrian anorogenic intraplate extensional period. Geochemically, the Tifnoute Valley granitoids belong to an alkali-calcic series (high-K calc-alkaline) with typical Nb-Ta negative anomalies and no alkaline affinities. Granitoids and enclaves display positive ɛNd-560Ma (+0.8 to +3.5) with young Nd-TDM between 800 and 1200 Ma and relatively low 87Sr/86Sr initial ratios (Sri: 0.7034 and 0.7065). These values indicate a mainly juvenile source corresponding to a Pan-African metasomatized lithospheric mantle partly mixed with an old crustal component from the underlying West African Craton (WAC). Preservation in the Anti-Atlas of pre-Pan-African lithologies (c. 2.03 Ga basement, c. 800 Ma passive margin greenschist-facies sediments, allochthonous 750-700 Ma ophiolitic sequences) indicates that the Anti-Atlas lithosphere has not been thickened and was never an active margin during the Neoproterozoic. After a transpressive period, the late Ediacaran period (580-545 Ma) is marked by movement on near vertical transtensional faults, synchronous with the emplacement of the huge Ouarzazate Group and the Tifnoute Valley granitoids. We propose here a geodynamical model where the Tifnoute Valley granitoids as well as the Ouarzazate Group were generated during the post

  9. Advanced quadrature sets and acceleration and preconditioning techniques for the discrete ordinates method in parallel computing environments

    NASA Astrophysics Data System (ADS)

    Longoni, Gianluca

    In the nuclear science and engineering field, radiation transport calculations play a key-role in the design and optimization of nuclear devices. The linear Boltzmann equation describes the angular, energy and spatial variations of the particle or radiation distribution. The discrete ordinates method (S N) is the most widely used technique for solving the linear Boltzmann equation. However, for realistic problems, the memory and computing time require the use of supercomputers. This research is devoted to the development of new formulations for the SN method, especially for highly angular dependent problems, in parallel environments. The present research work addresses two main issues affecting the accuracy and performance of SN transport theory methods: quadrature sets and acceleration techniques. New advanced quadrature techniques which allow for large numbers of angles with a capability for local angular refinement have been developed. These techniques have been integrated into the 3-D SN PENTRAN (Parallel Environment Neutral-particle TRANsport) code and applied to highly angular dependent problems, such as CT-Scan devices, that are widely used to obtain detailed 3-D images for industrial/medical applications. In addition, the accurate simulation of core physics and shielding problems with strong heterogeneities and transport effects requires the numerical solution of the transport equation. In general, the convergence rate of the solution methods for the transport equation is reduced for large problems with optically thick regions and scattering ratios approaching unity. To remedy this situation, new acceleration algorithms based on the Even-Parity Simplified SN (EP-SSN) method have been developed. A new stand-alone code system, PENSSn (Parallel Environment Neutral-particle Simplified SN), has been developed based on the EP-SSN method. The code is designed for parallel computing environments with spatial, angular and hybrid (spatial/angular) domain

  10. The Experience of Screening for HIV/AIDS Medical Studies among African-American/Black and Latino/Hispanic Persons Living with HIV/AIDS: A Mixed-Methods Exploration

    PubMed Central

    Engel, Stephanie; Gwadz, Marya Viorst; Cleland, Charles M

    2014-01-01

    Objective African-American/Black and Latino/Hispanic persons living with HIV/AIDS (i.e., “PLHA of color”) are under-represented in HIV/AIDS medical studies (HAMS). A crucial entry point into HAMS is screening, but PLHA of color face serious barriers to screening compared to Whites. Recently we evaluated a social/behavioral intervention that substantially increased rates of HAMS screening among PLHA of color. Yet very little is known about the actual screening experience for these under-represented subgroups. Thus, the objectives of the present study were to explore participants’ motivations for and experiences of HAMS screening. Methods A total of 186 participants in the larger study’s intervention arm were screened for HAMS, 35 of whom also participated in qualitative interviews. Participants engaged in a structured interview about the screening experience at 4- and 12- months post-baseline (14 items, Cronbach's α=0.72). Further, from a qualitative data set we purposively selected a set of three case studies to contextualize and enrich quantitative findings on screening experiences. Results The screening experience was overwhelmingly positive. Almost all participants reported being treated with dignity and respect, did not feel they were being treated like a “guinea pig,” and experienced a high level of trust in the setting and the screener, with no gender or racial/ethnic differences, and no differences based on whether participants were found eligible for HAMS during screening. A number of areas where screening could be improved were also identified. Conclusions Despite the complex barriers PLHA of color experience to screening for HAMS, the experience of screening was positive. Moreover, HAMS screening experiences were positive regardless of gender, race/ethnicity, or HAMS eligibility. HAMS screening can therefore be a productive learning experience that may reduce patient concerns about participating in HAMS. As such, fostering screening among

  11. High birthweights among infants of north African immigrants in Belgium.

    PubMed Central

    Buekens, P; Masuy-Stroobant, G; Delvaux, T

    1998-01-01

    OBJECTIVES: This study examined birthweights of North African immigrants in Belgium. METHODS: Analyses focused on Belgian single live birth certificates from 1981 to 1988. RESULTS: Low-birthweight (< 2500 g) rates were 3.1% among 34,686 newborns of North African origin and 4.8% among 804,286 newborns of Belgian origin. The entire North African birthweight distribution was shifted toward higher birthweights than the Belgian distribution. Low frequencies of low birthweights among North Africans were still observed after marital status, occupation of the father, and parity had been taken into account. CONCLUSIONS: Despite their low socioeconomic status, North African immigrants have high birthweights. PMID:9585752

  12. Flexible and scalable methods for quantifying stochastic variability in the era of massive time-domain astronomical data sets

    SciTech Connect

    Kelly, Brandon C.; Becker, Andrew C.; Sobolewska, Malgosia; Siemiginowska, Aneta; Uttley, Phil

    2014-06-10

    We present the use of continuous-time autoregressive moving average (CARMA) models as a method for estimating the variability features of a light curve, and in particular its power spectral density (PSD). CARMA models fully account for irregular sampling and measurement errors, making them valuable for quantifying variability, forecasting and interpolating light curves, and variability-based classification. We show that the PSD of a CARMA model can be expressed as a sum of Lorentzian functions, which makes them extremely flexible and able to model a broad range of PSDs. We present the likelihood function for light curves sampled from CARMA processes, placing them on a statistically rigorous foundation, and we present a Bayesian method to infer the probability distribution of the PSD given the measured light curve. Because calculation of the likelihood function scales linearly with the number of data points, CARMA modeling scales to current and future massive time-domain data sets. We conclude by applying our CARMA modeling approach to light curves for an X-ray binary, two active galactic nuclei, a long-period variable star, and an RR Lyrae star in order to illustrate their use, applicability, and interpretation.

  13. Multi-criteria decision-making methods with optimism and pessimism based on Atanassov's intuitionistic fuzzy sets

    NASA Astrophysics Data System (ADS)

    Chen, Ting-Yu

    2012-05-01

    The theory of Atanassov's intuitionistic fuzzy sets (A-IFSs) developed over the last several decades has found useful application in fields requiring multiple-criteria decision analysis. Since the membership-nonmembership pair in A-IFSs belongs to the bivariate unipolarity type, this article describes an approach that relates optimism and pessimism to multi-criteria decision analysis in an intuitionistic fuzzy-decision environment. First, several optimistic and pessimistic point operators were defined to alter the estimation of decision outcomes. Next, based on the core of the estimations, optimistic and pessimistic score functions were developed to evaluate each alternative with respect to each criterion. The suitability function was then established to determine the degree to which each an alternative satisfies the decision maker's requirement. Because the information on multiple criteria corresponding to decision importance is often incomplete, this study included suitability functions in the optimisation models to account for poorly known membership grades. Using a linear equal-weighted summation method, these models were transformed into a single objective optimisation model to generate the optimal weights for criteria. The feasibility and effectiveness of the proposed methods were illustrated through a practical example. Finally, computational experiments with enormous amounts of simulation data were designed to conduct a comparative analysis on the ranking orders yielded by different optimistic/pessimistic point operators.

  14. Budget- and Priority-Setting Criteria at State Health Agencies in Times of Austerity: A Mixed-Methods Study

    PubMed Central

    Resnick, Beth; Kass, Nancy; Sellers, Katie; Young, Jessica; Bernet, Patrick; Jarris, Paul

    2014-01-01

    Objectives. We examined critical budget and priority criteria for state health agencies to identify likely decision-making factors, pressures, and opportunities in times of austerity. Methods. We have presented findings from a 2-stage, mixed-methods study with state public health leaders regarding public health budget- and priority-setting processes. In stage 1, we conducted hour-long interviews in 2011 with 45 health agency executive and division or bureau leaders from 6 states. Stage 2 was an online survey of 207 executive and division or bureau leaders from all state health agencies (66% response rate). Results. Respondents identified 5 key criteria: whether a program was viewed as “mission critical,” the seriousness of the consequences of not funding the program, financing considerations, external directives and mandates, and the magnitude of the problem the program addressed. Conclusions. We have presented empirical findings on criteria used in state health agency budgetary decision-making. These criteria suggested a focus and interest on core public health and the largest public health problems with the most serious ramifications. PMID:24825212

  15. Modelling calving front dynamics using a level-set method: application to Jakobshavn Isbræ, West Greenland

    NASA Astrophysics Data System (ADS)

    Bondzio, Johannes H.; Seroussi, Hélène; Morlighem, Mathieu; Kleiner, Thomas; Rückamp, Martin; Humbert, Angelika; Larour, Eric Y.

    2016-03-01

    Calving is a major mechanism of ice discharge of the Antarctic and Greenland ice sheets, and a change in calving front position affects the entire stress regime of marine terminating glaciers. The representation of calving front dynamics in a 2-D or 3-D ice sheet model remains non-trivial. Here, we present the theoretical and technical framework for a level-set method, an implicit boundary tracking scheme, which we implement into the Ice Sheet System Model (ISSM). This scheme allows us to study the dynamic response of a drainage basin to user-defined calving rates. We apply the method to Jakobshavn Isbræ, a major marine terminating outlet glacier of the West Greenland Ice Sheet. The model robustly reproduces the high sensitivity of the glacier to calving, and we find that enhanced calving triggers significant acceleration of the ice stream. Upstream acceleration is sustained through a combination of mechanisms. However, both lateral stress and ice influx stabilize the ice stream. This study provides new insights into the ongoing changes occurring at Jakobshavn Isbræ and emphasizes that the incorporation of moving boundaries and dynamic lateral effects, not captured in flow-line models, is key for realistic model projections of sea level rise on centennial timescales.

  16. Mechanical behavior of pathological and normal red blood cells in microvascular flow based on modified level-set method

    NASA Astrophysics Data System (ADS)

    Zhang, XiWen; Ma, FangChao; Hao, PengFei; Yao, ZhaoHui

    2016-01-01

    The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompressible fluid. The numerical model satisfies mass and energy conservation without the leaking problems in classical Immersed Boundary Method (IBM), at the same time, computing grid we used can be much smaller than the general literatures. The motion and deformation of a red blood cell (including pathological & normal status) in microvascular flow are simulated. It is found that the Reynolds number and membrane's stiffness play an important role in the transmutation and oscillation of the elastic membrane. The normal biconcave shape of the RBC is propitious to create high deformation than other pathological shapes. With reduced viscosity of the interior fluid both the velocity of the blood and the deformability of the cell reduced. With increased viscosity of the plasma both the velocity of the blood and the deformability of the cell reduced. The tank treading of the RBC membrane is observed at low enough viscosity contrast in shear flow. The tank tread fixed inclination angle of the cell depends on the shear ratio and viscosity contrast, which can be compared with the experimental observation well.

  17. Watching Transitions Unfold: A Mixed-Method Study of Transitions within Early Childhood Care and Education Settings

    ERIC Educational Resources Information Center

    O'Farrelly, Christine; Hennessy, Eilis

    2014-01-01

    Unlike the transitions children make between settings, those they undertake between age groups within early childhood care and education (ECCE) settings are seldom studied. Accordingly, this exploratory study followed seven preschool children (three boys and four girls) as they moved to new rooms in five ECCE settings. Structured observations of…

  18. Identification of Growth Phases and Influencing Factors in Cultivations with AGE1.HN Cells Using Set-Based Methods

    PubMed Central

    Borchers, Steffen; Freund, Susann; Rath, Alexander; Streif, Stefan; Reichl, Udo; Findeisen, Rolf

    2013-01-01

    Production of bio-pharmaceuticals in cell culture, such as mammalian cells, is challenging. Mathematical models can provide support to the analysis, optimization, and the operation of production processes. In particular, unstructured models are suited for these purposes, since they can be tailored to particular process conditions. To this end, growth phases and the most relevant factors influencing cell growth and product formation have to be identified. Due to noisy and erroneous experimental data, unknown kinetic parameters, and the large number of combinations of influencing factors, currently there are only limited structured approaches to tackle these issues. We outline a structured set-based approach to identify different growth phases and the factors influencing cell growth and metabolism. To this end, measurement uncertainties are taken explicitly into account to bound the time-dependent specific growth rate based on the observed increase of the cell concentration. Based on the bounds on the specific growth rate, we can identify qualitatively different growth phases and (in-)validate hypotheses on the factors influencing cell growth and metabolism. We apply the approach to a mammalian suspension cell line (AGE1.HN). We show that growth in batch culture can be divided into two main growth phases. The initial phase is characterized by exponential growth dynamics, which can be described consistently by a relatively simple unstructured and segregated model. The subsequent phase is characterized by a decrease in the specific growth rate, which, as shown, results from substrate limitation and the pH of the medium. An extended model is provided which describes the observed dynamics of cell growth and main metabolites, and the corresponding kinetic parameters as well as their confidence intervals are estimated. The study is complemented by an uncertainty and outlier analysis. Overall, we demonstrate utility of set-based methods for analyzing cell growth and

  19. Identification of growth phases and influencing factors in cultivations with AGE1.HN cells using set-based methods.

    PubMed

    Borchers, Steffen; Freund, Susann; Rath, Alexander; Streif, Stefan; Reichl, Udo; Findeisen, Rolf

    2013-01-01

    Production of bio-pharmaceuticals in cell culture, such as mammalian cells, is challenging. Mathematical models can provide support to the analysis, optimization, and the operation of production processes. In particular, unstructured models are suited for these purposes, since they can be tailored to particular process conditions. To this end, growth phases and the most relevant factors influencing cell growth and product formation have to be identified. Due to noisy and erroneous experimental data, unknown kinetic parameters, and the large number of combinations of influencing factors, currently there are only limited structured approaches to tackle these issues. We outline a structured set-based approach to identify different growth phases and the factors influencing cell growth and metabolism. To this end, measurement uncertainties are taken explicitly into account to bound the time-dependent specific growth rate based on the observed increase of the cell concentration. Based on the bounds on the specific growth rate, we can identify qualitatively different growth phases and (in-)validate hypotheses on the factors influencing cell growth and metabolism. We apply the approach to a mammalian suspension cell line (AGE1.HN). We show that growth in batch culture can be divided into two main growth phases. The initial phase is characterized by exponential growth dynamics, which can be described consistently by a relatively simple unstructured and segregated model. The subsequent phase is characterized by a decrease in the specific growth rate, which, as shown, results from substrate limitation and the pH of the medium. An extended model is provided which describes the observed dynamics of cell growth and main metabolites, and the corresponding kinetic parameters as well as their confidence intervals are estimated. The study is complemented by an uncertainty and outlier analysis. Overall, we demonstrate utility of set-based methods for analyzing cell growth and

  20. An exploratory GIS-based method to identify and characterise landscapes with an elevated epidemiological risk of Rhodesian human African trypanosomiasis

    PubMed Central

    2012-01-01

    Background Specific land cover types and activities have been correlated with Trypanosoma brucei rhodesiense distributions, indicating the importance of landscape for epidemiological risk. However, methods proposed to identify specific areas with elevated epidemiological risk (i.e. where transmission is more likely to occur) tend to be costly and time consuming. This paper proposes an exploratory spatial analysis using geo-referenced human African trypanosomiasis (HAT) cases and matched controls from Serere hospital, Uganda (December 1998 to November 2002) to identify areas with an elevated epidemiological risk of HAT. Methods Buffers 3 km from each case and control were used to represent areas in which village inhabitants would carry out their daily activities. It was hypothesised that the selection of areas where several case village buffers overlapped would enable the identification of locations with increased risk of HAT transmission, as these areas were more likely to be frequented by HAT cases in several surrounding villages. The landscape within these overlap areas should more closely relate to the environment in which transmission occurs as opposed to using the full buffer areas. The analysis was carried out for each of four annual periods, for both cases and controls, using a series of threshold values (number of overlapping buffers), including a threshold of one, which represented the benchmark (e.g. use of the full buffer area as opposed to the overlap areas). Results A greater proportion of the overlap areas for cases consisted of seasonally flooding grassland and lake fringe swamp, than the control overlap areas, correlating well with the preferred habitat of the predominant tsetse species within the study area (Glossina fuscipes fuscipes). The use of overlap areas also resulted in a greater difference between case and control landscapes, when compared with the benchmark (using the full buffer area). Conclusions These results indicate that the overlap

  1. Food Group Categories of Low-Income African American Women

    ERIC Educational Resources Information Center

    Lynch, Elizabeth B.; Holmes, Shane

    2011-01-01

    Objective: Describe lay food group categories of low-income African American women and assess the overlap of lay food groups and MyPyramid food groups. Design: A convenience sample of African American mothers from a low-income Chicago neighborhood performed a card-sorting task in which they grouped familiar food items into food groups. Setting:…

  2. African American English: Implications for School Counseling Professionals

    ERIC Educational Resources Information Center

    Day-Vines, Norma L.; Barto, Heather H.; Booker, Beverly L.; Smith, Kim V.; Barna, Jennifer; Maiden, Brian S.; Zegley, Linda; Felder, Monique T.

    2009-01-01

    African American English (AAE) refers to the systematic, rule-governed linguistic patterns of found among African Americans. This article provides an overview of AAE. More specifically, the article enumerates the historical underpinnings associated with AAE, identifies a representative set of AAE characteristics, reviews relevant research, and…

  3. Diagnostic Accuracy of the Small Membrane Filtration Method for Diagnosis of Pulmonary Tuberculosis in a High-HIV-Prevalence Setting.

    PubMed

    Boum, Yap; Kim, Soyeon; Orikiriza, Patrick; Acuña-Villaorduña, Carlos; Vinhas, Solange; Bonnet, Maryline; Nyehangane, Dan; Mwanga-Amumpaire, Juliet; Fennelly, Kevin P; Jones-López, Edward C

    2016-06-01

    Sputum acid-fast bacilli (AFB) smear microscopy has suboptimal sensitivity but remains the most commonly used laboratory test to diagnose pulmonary tuberculosis (TB). We prospectively evaluated the small membrane filtration (SMF) method that concentrates AFB in a smaller area to facilitate detection to improve the diagnostic performance of microscopy. We enrolled adults with suspicion of pulmonary TB from health facilities in southwestern Uganda. Clinical history, physical examination, and 3 sputum samples were obtained for direct fluorescent AFB smear, SMF, Xpert MTB/RIF, and MGIT culture media. Sensitivity and specificity were estimated for SMF, AFB smear, and Xpert MTB/RIF, using MGIT as the reference standard. The analysis was stratified according to HIV status. From September 2012 to April 2014, 737 participants were included in the HIV-infected stratum (146 [20.5%] were culture positive) and 313 were in the HIV-uninfected stratum (85 [28%] were culture positive). In HIV-infected patients, the sensitivity of a single SMF was 67.4% (95% confidence interval [CI], 59.9% to 74.1%); for AFB, 68.0% (95% CI, 60.6% to 74.6%); and for Xpert MTB/RIF, 91.0% (95% CI, 85.0% to 94.8%). In HIV-uninfected patients, the corresponding sensitivities were 72.5% (95% CI, 62.1% to 80.9%), 80.3% (95% CI, 70.8% to 87.2%), and 93.5% (95% CI, 85.7% to 97.2%). The specificity for all 3 tests in both HIV groups was ≥96%. In this setting, the SMF method did not improve the diagnostic accuracy of sputum AFB. The Xpert MTB/RIF assay performed well in both HIV-infected and -uninfected groups. PMID:27030493

  4. Multilocus Phylogeography and Species Delimitation in the Cumberland Plateau Salamander, Plethodon kentucki: Incongruence among Data Sets and Methods

    PubMed Central

    Kuchta, Shawn R.; Brown, Ashley D.; Converse, Paul E.; Highton, Richard

    2016-01-01

    Species are a fundamental unit of biodiversity, yet can be challenging to delimit objectively. This is particularly true of species complexes characterized by high levels of population genetic structure, hybridization between genetic groups, isolation by distance, and limited phenotypic variation. Previous work on the Cumberland Plateau Salamander, Plethodon kentucki, suggested that it might constitute a species complex despite occupying a relatively small geographic range. To examine this hypothesis, we sampled 135 individuals from 43 populations, and used four mitochondrial loci and five nuclear loci (5693 base pairs) to quantify phylogeographic structure and probe for cryptic species diversity. Rates of evolution for each locus were inferred using the multidistribute package, and time calibrated gene trees and species trees were inferred using BEAST 2 and *BEAST 2, respectively. Because the parameter space relevant for species delimitation is large and complex, and all methods make simplifying assumptions that may lead them to fail, we conducted an array of analyses. Our assumption was that strongly supported species would be congruent across methods. Putative species were first delimited using a Bayesian implementation of the GMYC model (bGMYC), Geneland, and Brownie. We then validated these species using the genealogical sorting index and BPP. We found substantial phylogeographic diversity using mtDNA, including four divergent clades and an inferred common ancestor at 14.9 myr (95% HPD: 10.8–19.7 myr). By contrast, this diversity was not corroborated by nuclear sequence data, which exhibited low levels of variation and weak phylogeographic structure. Species trees estimated a far younger root than did the mtDNA data, closer to 1.0 myr old. Mutually exclusive putative species were identified by the different approaches. Possible causes of data set discordance, and the problem of species delimitation in complexes with high levels of population structure and

  5. Multilocus Phylogeography and Species Delimitation in the Cumberland Plateau Salamander, Plethodon kentucki: Incongruence among Data Sets and Methods.

    PubMed

    Kuchta, Shawn R; Brown, Ashley D; Converse, Paul E; Highton, Richard

    2016-01-01

    Species are a fundamental unit of biodiversity, yet can be challenging to delimit objectively. This is particularly true of species complexes characterized by high levels of population genetic structure, hybridization between genetic groups, isolation by distance, and limited phenotypic variation. Previous work on the Cumberland Plateau Salamander, Plethodon kentucki, suggested that it might constitute a species complex despite occupying a relatively small geographic range. To examine this hypothesis, we sampled 135 individuals from 43 populations, and used four mitochondrial loci and five nuclear loci (5693 base pairs) to quantify phylogeographic structure and probe for cryptic species diversity. Rates of evolution for each locus were inferred using the multidistribute package, and time calibrated gene trees and species trees were inferred using BEAST 2 and *BEAST 2, respectively. Because the parameter space relevant for species delimitation is large and complex, and all methods make simplifying assumptions that may lead them to fail, we conducted an array of analyses. Our assumption was that strongly supported species would be congruent across methods. Putative species were first delimited using a Bayesian implementation of the GMYC model (bGMYC), Geneland, and Brownie. We then validated these species using the genealogical sorting index and BPP. We found substantial phylogeographic diversity using mtDNA, including four divergent clades and an inferred common ancestor at 14.9 myr (95% HPD: 10.8-19.7 myr). By contrast, this diversity was not corroborated by nuclear sequence data, which exhibited low levels of variation and weak phylogeographic structure. Species trees estimated a far younger root than did the mtDNA data, closer to 1.0 myr old. Mutually exclusive putative species were identified by the different approaches. Possible causes of data set discordance, and the problem of species delimitation in complexes with high levels of population structure and

  6. Setting method of parameters for SN transition fault current limiter into 6.6kV distribution system

    NASA Astrophysics Data System (ADS)

    Kameda (Criepi, H.; Torii(Criepi, S.

    2008-02-01

    A fault current limiter (FCL) is an outstanding apparatus which the impedance does not appear when no fault occurs, but the impedance appears only when a fault occurs in a power system. The operation of the FCL causes the effective reduction of the fault current. Although there are various kinds of FCLs in principles which have ever proposed, we think that a SN transition FCL with small normal loss will be promising since it is connected in series. However, we need to solve many problems toward practical use. In this paper, we propose the setting method of the parameters in the case of applying a SN transition FCLs to the feeders, or the busbar, or the lower voltage side of the transformers in the 6.6kV model distribution system. And we evaluate how to introduce the FCLs into it from the point of the requirements and the design. Finally, we suggest the hopeful installation of the FCLs into the distribution system.

  7. Assessing health impacts in complex eco-epidemiological settings in the humid tropics: Advancing tools and methods

    SciTech Connect

    Winkler, Mirko S.; Divall, Mark J.; Krieger, Gary R.; Balge, Marci Z.; Singer, Burton H.; Utzinger, Juerg

    2010-01-15

    In the developing world, large-scale projects in the extractive industry and natural resources sectors are often controversial and associated with long-term adverse health consequences to local communities. In many industrialised countries, health impact assessment (HIA) has been institutionalized for the mitigation of anticipated negative health effects while enhancing the benefits of projects, programmes and policies. However, in developing country settings, relatively few HIAs have been performed. Hence, more HIAs with a focus on low- and middle-income countries are needed to advance and refine tools and methods for impact assessment and subsequent mitigation measures. We present a promising HIA approach, developed within the frame of a large gold-mining project in the Democratic Republic of the Congo. The articulation of environmental health areas, the spatial delineation of potentially affected communities and the use of a diversity of sources to obtain quality baseline health data are utilized for risk profiling. We demonstrate how these tools and data are fed into a risk analysis matrix, which facilitates ranking of potential health impacts for subsequent prioritization of mitigation strategies. The outcomes encapsulate a multitude of environmental and health determinants in a systematic manner, and will assist decision-makers in the development of mitigation measures that minimize potential adverse health effects and enhance positive ones.

  8. A particle-level set-based sharp interface cartesian grid method for impact, penetration, and void collapse

    NASA Astrophysics Data System (ADS)

    Tran, L. B.; Udaykumar, H. S.

    2004-01-01

    An Eulerian, sharp interface, Cartesian grid method is developed for the numerical simulation of the response of materials to impact, shocks and detonations. The mass, momentum, and energy equations are solved along with evolution equations for deviatoric stresses and equivalent plastic strain. These equations are cast in Eulerian conservation law form. The Mie-Grüneisen equation of state is used to obtain pressure and the material is modeled as a Johnson-Cook solid. The ENO scheme is employed to capture shocks in combination with a hybrid particle level set technique to evolve sharp immersed boundaries. The numerical technique is able to handle collisions between multiple materials and can accurately compute the dynamics of the immersed boundaries. Results of calculations for axisymmetric Taylor bar impact and penetration of a Tungsten rod into steel plate show good agreement with moving finite element solutions and experimental results. Qualitative agreement with theory is shown for the void collapse phenomenon in an impacted material containing a spherical void.

  9. Web-MCQ: a set of methods and freely available open source code for administering online multiple choice question assessments.

    PubMed

    Hewson, Claire

    2007-08-01

    E-learning approaches have received increasing attention in recent years. Accordingly, a number of tools have become available to assist the nonexpert computer user in constructing and managing virtual learning environments, and implementing computer-based and/or online procedures to support pedagogy. Both commercial and free packages are now available, with new developments emerging periodically. Commercial products have the advantage of being comprehensive and reliable, but tend to require substantial financial investment and are not always transparent to use. They may also restrict pedagogical choices due to their predetermined ranges of functionality. With these issues in mind, several authors have argued for the pedagogical benefits of developing freely available, open source e-learning resources, which can be shared and further developed within a community of educational practitioners. The present paper supports this objective by presenting a set of methods, along with supporting freely available, downloadable, open source programming code, to allow administration of online multiple choice question assessments to students. PMID:17958158

  10. Using Frequent Item Set Mining and Feature Selection Methods to Identify Interacted Risk Factors - The Atrial Fibrillation Case Study.

    PubMed

    Li, Xiang; Liu, Haifeng; Du, Xin; Hu, Gang; Xie, Guotong; Zhang, Ping

    2016-01-01

    Disease risk prediction is highly important for early intervention and treatment, and identification of predictive risk factors is the key point to achieve accurate prediction. In addition to original independent features in a dataset, some interacted features, such as comorbidities and combination therapies, may have non-additive influence on the disease outcome and can also be used in risk prediction to improve the prediction performance. However, it is usually difficult to manually identify the possible interacted risk factors due to the combination explosion of features. In this paper, we propose an automatic approach to identify predictive risk factors with interactions using frequent item set mining and feature selection methods. The proposed approach was applied in the real world case study of predicting ischemic stroke and thromboembolism for atrial fibrillation patients on the Chinese atrial fibrillation registry dataset, and the results show that our approach can not only improve the prediction performance, but also identify the comorbidities and combination therapies that have potential influences on TE occurrence for AF. PMID:27577446

  11. On the use of the resting potential and level set methods for identifying ischemic heart disease: An inverse problem

    NASA Astrophysics Data System (ADS)

    Nielsen, Bjørn Fredrik; Lysaker, Marius; Tveito, Aslak

    2007-01-01

    The electrical activity in the heart is modeled by a complex, nonlinear, fully coupled system of differential equations. Several scientists have studied how this model, referred to as the bidomain model, can be modified to incorporate the effect of heart infarctions on simulated ECG (electrocardiogram) recordings. We are concerned with the associated inverse problem; how can we use ECG recordings and mathematical models to identify the position, size and shape of heart infarctions? Due to the extreme CPU efforts needed to solve the bidomain equations, this model, in its full complexity, is not well-suited for this kind of problems. In this paper we show how biological knowledge about the resting potential in the heart and level set techniques can be combined to derive a suitable stationary model, expressed in terms of an elliptic PDE, for such applications. This approach leads to a nonlinear ill-posed minimization problem, which we propose to regularize and solve with a simple iterative scheme. Finally, our theoretical findings are illuminated through a series of computer simulations for an experimental setup involving a realistic heart in torso geometry. More specifically, experiments with synthetic ECG recordings, produced by solving the bidomain model, indicate that our method manages to identify the physical characteristics of the ischemic region(s) in the heart. Furthermore, the ill-posed nature of this inverse problem is explored, i.e. several quantitative issues of our scheme are explored.

  12. [West African childbirth traditions].

    PubMed

    Hallgren, R

    1983-11-01

    Religious and medical practices are steeped in the traditions of West African culture vis-a-vis childbirth. It is customary for delivery to occur with the woman squatting on the ground surrounded by sisters and female relatives, some of whom function as midwives. Midwives get paid only if delivery is successful. A stool is also often used in childbirth. The name given to a child in the Yoruba tribe in Nigeria has to refer to the circumstances of the individual's birth. The contact with the earth (as in the squatting position) has religious overtones--it indicates the fecundity of the earth, and the mother's contact with it. Infertility is considered the greatest tragedy in traditional African society. In Senegal, a childless woman pays a fertile one a certain sum in return for bearing her a child who would be raised as her own (this tradition is not unlike surrogate motherhood in Western countries). Men are never present at birth; however, in urban settings this practice is changing. The burial of the placenta and umbilical cord is thought to restore the woman's fertility and help heal her womb. This practice was even recorded in 19th century Sweden harkening back to heathen times. In Ghana, an infertile woman urinates on the ground where the placenta is buried in the belief that her fertility will be restored. The birth of twins is regarded as a great blessing, and as a sign of fertility; however, the inability of the mother to breast-feed both twins may result in the death of the weaker child. The harmony of nature, animals, and human beings is paramount in traditional West Africa religion and life, and undoubtedly Western culture could learn from some of these beliefs. PMID:6558064

  13. Supernova Spectroscopy with the Southern African Large Telescope

    NASA Astrophysics Data System (ADS)

    Pandya, Viraj; Jha, S.; McCully, C.; Patel, B.; Camacho, Y.

    2014-01-01

    Supernova (SN) spectroscopy is important not only for classification and redshifts, but it also allows us to probe explosion mechanisms and progenitors. Here we report on optical spectroscopy of recent SNe using the Southern African Large Telescope (SALT) with the Robert Stobie Spectrograph (RSS). We have developed an automated data reduction pipeline for our longslit SN observations, paying particular attention to combining multiple exposures with different wavelength settings spanning the optical range. Furthermore, we investigate and implement an automated method for removing telluric features in the spectra. Finally, we present results exploring spectrum synthesis to model our growing database of type Ia supernovae.

  14. The UCAR Africa Initiative: Enabling African Solutions to African Needs

    NASA Astrophysics Data System (ADS)

    Pandya, R.; Bruintjes, R.; Foote, B.; Heck, S.; Hermann, S.; Hoswell, L.; Konate, M.; Kucera, P.; Laing, A.; Lamptey, B.; Moncrieff, M.; Ramamurthy, M.; Roberts, R.; Spangler, T.; Traoré, A.; Yoksas, T.; Warner, T.

    2007-12-01

    The University Corporation for Atmospheric Research (UCAR) Africa Initiative (AI) is a coordinated effort aimed at building sustainable partnerships between UCAR and African institutions in order to pursue research and applications for the benefit of the African people. The initiative is based on four fundamental operating principles, concisely summarized by the overall philosophy of enabling African solutions to African needs. The four principles are: • Collaborate with African institutions • Focus on institutional capacity building and research support • Explore science research themes critical to Africa and important for the world • Leverage the research infrastructure in UCAR to add value These principles are realized in a set of pilot activities, chosen for their high probability of short-term results and ability to set the stage for longer-term collaboration. The three pilot activities are listed below. 1. A modest radar network and data-distribution system in Mali and Burkina Faso, including a data-sharing MOU between the Mail and Burkina Faso Weather Services. 2. A partnership among UCAR, the Ghana Meteorological Agency, and the Ghana university community to develop an operational Weather Research and Forecasting (WRF) model for West Africa. The output is used by researchers and operational forecasters in Africa. Model output is also part of a demonstration project that aims to allow humanitarian agencies to share geo-referenced information in Africa via a web portal. 3. A workshop in Ouagadougou, Burkina Faso from April 2-6, 2007, with the theme Improving Lives by Understanding Weather. The workshop, co-organized with Programme SAAGA and the Commité Permanent Inter-Etats de Lutte Contre la Sécheresse dans le Sahel (CILSS), included over 80 participants from 18 countries, and produced a set of recommendations for continued collaboration. Our presentation will provide an update of these pilot activities and point to future directions. Recognizing

  15. H.U.B city steps: methods and early findings from a community-based participatory research trial to reduce blood pressure among african americans

    PubMed Central

    2011-01-01

    Background Community-based participatory research (CBPR) has been recognized as an important approach to develop and execute health interventions among marginalized populations, and a key strategy to translate research into practice to help reduce health disparities. Despite growing interest in the CBPR approach, CBPR initiatives rarely use experimental or other rigorous research designs to evaluate health outcomes. This behavioral study describes the conceptual frameworks, methods, and early findings related to the reach, adoption, implementation, and effectiveness on primary blood pressure outcomes. Methods The CBPR, social support, and motivational interviewing frameworks are applied to test treatment effects of a two-phased CBPR walking intervention, including a 6-month active intervention quasi experimental phase and 12-month maintenance randomized controlled trial phase to test dose effects of motivational interviewing. A community advisory board helped develop and execute the culturally-appropriate intervention components which included social support walking groups led by peer coaches, pedometer diary self-monitoring, monthly diet and physical activity education sessions, and individualized motivational interviewing sessions. Although the study is on-going, three month data is available and reported. Analyses include descriptive statistics and paired t tests. Results Of 269 enrolled participants, most were African American (94%) females (85%) with a mean age of 43.8 (SD = 12.1) years. Across the 3 months, 90% of all possible pedometer diaries were submitted. Attendance at the monthly education sessions was approximately 33%. At the 3-month follow-up 227 (84%) participants were retained. From baseline to 3-months, systolic BP [126.0 (SD = 19.1) to 120.3 (SD = 17.9) mmHg; p < 0.001] and diastolic BP [83. 2 (SD = 12.3) to 80.2 (SD = 11.6) mmHg; p < 0.001] were significantly reduced. Conclusions This CBPR study highlights implementation factors and signifies

  16. African and non-African admixture components in African Americans and an African Caribbean population.

    PubMed

    Murray, Tanda; Beaty, Terri H; Mathias, Rasika A; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U; Watson, Harold R; Ruczinski, Ingo; Dunston, Georgia M; Barnes, Kathleen C

    2010-09-01

    Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r(2)=0.992, r(2)=0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on approximately 14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (F(ST)). We found AAs and ACs were closest genetically (F(ST)=0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, approximately 400 well-defined AIMs were just as good for detecting substructure as approximately 14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

  17. Approaching the complete basis set limit of CCSD(T) for large systems by the third-order incremental dual-basis set zero-buffer F12 method

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Dolg, Michael

    2014-01-01

    The third-order incremental dual-basis set zero-buffer approach was combined with CCSD(T)-F12x (x = a, b) theory to develop a new approach, i.e., the inc3-db-B0-CCSD(T)-F12 method, which can be applied as a black-box procedure to efficiently obtain the near complete basis set (CBS) limit of the CCSD(T) energies also for large systems. We tested this method for several cases of different chemical nature: four complexes taken from the standard benchmark sets S66 and X40, the energy difference between isomers of water hexamer and the rotation barrier of biphenyl. The results show that our method has an error relative to the best estimation of CBS energy of only 0.2 kcal/mol or less. By parallelization, our method can accomplish the CCSD(T)-F12 calculations of about 60 correlated electrons and 800 basis functions in only several days, which by standard implementation are impossible for ordinary hardware. We conclude that the inc3-db-B0-CCSD(T)-F12a/AVTZ method, which is of CCSD(T)/AV5Z quality, is close to the limit of accuracy that one can achieve for large systems currently.

  18. Approaching the complete basis set limit of CCSD(T) for large systems by the third-order incremental dual-basis set zero-buffer F12 method

    SciTech Connect

    Zhang, Jun Dolg, Michael

    2014-01-28

    The third-order incremental dual-basis set zero-buffer approach was combined with CCSD(T)-F12x (x = a, b) theory to develop a new approach, i.e., the inc3-db-B0-CCSD(T)-F12 method, which can be applied as a black-box procedure to efficiently obtain the near complete basis set (CBS) limit of the CCSD(T) energies also for large systems. We tested this method for several cases of different chemical nature: four complexes taken from the standard benchmark sets S66 and X40, the energy difference between isomers of water hexamer and the rotation barrier of biphenyl. The results show that our method has an error relative to the best estimation of CBS energy of only 0.2 kcal/mol or less. By parallelization, our method can accomplish the CCSD(T)-F12 calculations of about 60 correlated electrons and 800 basis functions in only several days, which by standard implementation are impossible for ordinary hardware. We conclude that the inc3-db-B0-CCSD(T)-F12a/AVTZ method, which is of CCSD(T)/AV5Z quality, is close to the limit of accuracy that one can achieve for large systems currently.

  19. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  20. Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

    NASA Astrophysics Data System (ADS)

    Picolloto, A. M.; Mariucci, V. V. G.; Szpak, W.; Medina, A. N.; Baesso, M. L.; Astrath, N. G. C.; Astrath, F. B. G.; Santos, A. D.; Moraes, J. C. S.; Bento, A. C.

    2013-11-01

    The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (˜7 min) and with similar thermal expansion (˜12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10-3 cm2/s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s0.5/cm2 K and volume heat capacity (5.2 ± 0.7) J/cm3 K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water).