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Sample records for investigate intra-hospital variation

  1. Overcoming language barriers with foreign-language speaking patients: a survey to investigate intra-hospital variation in attitudes and practices

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    Vilpert Sarah

    2009-10-01

    Full Text Available Abstract Background Use of available interpreter services by hospital clincial staff is often suboptimal, despite evidence that trained interpreters contribute to quality of care and patient safety. Examination of intra-hospital variations in attitudes and practices regarding interpreter use can contribute to identifying factors that facilitate good practice. The purpose of this study was to describe attitudes, practices and preferences regarding communication with limited French proficiency (LFP patients, examine how these vary across professions and departments within the hospital, and identify factors associated with good practices. Methods A self-administered questionnaire was mailed to random samples of 700 doctors, 700 nurses and 93 social workers at the Geneva University Hospitals, Switzerland. Results Seventy percent of respondents encounter LFP patients at least once a month, but this varied by department. 66% of respondents said they preferred working with ad hoc interpreters (patient's family and bilingual staff, mainly because these were easier to access. During the 6 months preceding the study, ad hoc interpreters were used at least once by 71% of respondents, and professional interpreters were used at least once by 51%. Overall, only nine percent of respondents had received any training in how and why to work with a trained interpreter. Only 23.2% of respondents said the clinical service in which they currently worked encouraged them to use professional interpreters. Respondents working in services where use of professional interpreters was encouraged were more likely to be of the opinion that the hospital should systematically provide a professional interpreter to LFP patients (40.3% as compared with those working in a department that discouraged use of professional interpreters (15.5% and they used professional interpreters more often during the previous 6 months. Conclusion Attitudes and practices regarding communication with

  2. Overcoming language barriers with foreign-language speaking patients: a survey to investigate intra-hospital variation in attitudes and practices.

    Science.gov (United States)

    Hudelson, Patricia; Vilpert, Sarah

    2009-10-15

    Use of available interpreter services by hospital clinical staff is often suboptimal, despite evidence that trained interpreters contribute to quality of care and patient safety. Examination of intra-hospital variations in attitudes and practices regarding interpreter use can contribute to identifying factors that facilitate good practice. The purpose of this study was to describe attitudes, practices and preferences regarding communication with limited French proficiency (LFP) patients, examine how these vary across professions and departments within the hospital, and identify factors associated with good practices. A self-administered questionnaire was mailed to random samples of 700 doctors, 700 nurses and 93 social workers at the Geneva University Hospitals, Switzerland. Seventy percent of respondents encounter LFP patients at least once a month, but this varied by department. 66% of respondents said they preferred working with ad hoc interpreters (patient's family and bilingual staff), mainly because these were easier to access. During the 6 months preceding the study, ad hoc interpreters were used at least once by 71% of respondents, and professional interpreters were used at least once by 51%. Overall, only nine percent of respondents had received any training in how and why to work with a trained interpreter. Only 23.2% of respondents said the clinical service in which they currently worked encouraged them to use professional interpreters. Respondents working in services where use of professional interpreters was encouraged were more likely to be of the opinion that the hospital should systematically provide a professional interpreter to LFP patients (40.3%) as compared with those working in a department that discouraged use of professional interpreters (15.5%) and they used professional interpreters more often during the previous 6 months. Attitudes and practices regarding communication with LFP patients vary across professions and hospital departments. In

  3. The Relationship between Serum Hemoglobin and Creatinine Levels and Intra-Hospital Mortality and Morbidity in Acute Myocardial Infarction

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    Afsoon Fazlinezhad

    2014-09-01

    Full Text Available Background: Studies have shown that Glomerular Filtration Rate (GFR and Hemoglobin (Hb concentrations are two predictive values for ST-elevation Myocardial Infarction (MI mortality.. Objectives: This study aimed to investigate the relationship between GFR and Hb concentrations and intra-hospital mortality and electrocardiographic (ECG and echocardiographic abnormalities in ST-elevation MI patients admitted to a highly equipped hospital in Mashhad. The results will help define some factors to manage these patients more efficiently.. Patients and Methods: This descriptive study aimed to assess the relationship between Hb and GFR concentrations and mortality and morbidity among 294 randomly selected patients with ST-elevation MI. Echocardiography, ECG, and routine laboratory tests, including Hb and creatinine, were performed for all the patients. Then, the data were entered into the SPSS statistical software, version 16 and were analyzed using chi-square, t-test, and ANOVA. P < 0.05 was considered as statistically significant.. Results: Intra-hospital mortality rate was 10.5%. Besides, the results showed higher levels of serum blood sugar (P < 0.001, higher levels of creatinine (P < 0.001, lower levels of GFR (P < 0.001, lower ejection fraction (P < 0.001, higher grades of left ventricular diastolic dysfunction (P = 0.002, and lower mean Hb concentration (P = 0.022 in the dead compared to the alive cases. Besides, the patients with mechanical complications had lower Hb levels (P = 0.008. The results showed no significant relationship between creatinine level and mechanical and electrical complications (P = 0.430 and P = 0.095, respectively. However, ejection fraction was significantly associated with GFR (P = 0.016.. Conclusions: According to the results, low levels of Hb and GFR could predict mortality caused by ST-elevation MI and ECG abnormalities could notify intra-hospital death. Moreover, lower Hb levels were associated with mechanical

  4. Intra-hospital organ and tissue donation coordination project: cost-effectiveness and social benefits

    OpenAIRE

    Silva, Vanessa Silva e; Moura, Luciana Carvalho; Leite, Renata Fabiana; Oliveira, Priscilla Caroliny de; Schirmer, Janine; Roza, Bartira De' Aguiar

    2015-01-01

    OBJECTIVE To evaluate the viability of a professional specialist in intra-hospital committees of organ and tissue donation for transplantation. METHODS Epidemiological, retrospective and cross-sectional study (2003-2011 and 2008-2012), which was performed using organ donation for transplants data in the state of Sao Paulo, Southeastern Brazil. Nine hospitals were evaluated (hospitals 1 to 9). Logistic regression was used to evaluate the differences in the number of brain death referrals an...

  5. Intra-hospital organ and tissue donation coordination project: cost-effectiveness and social benefits

    Science.gov (United States)

    Silva, Vanessa Silva e; Moura, Luciana Carvalho; Leite, Renata Fabiana; de Oliveira, Priscilla Caroliny; Schirmer, Janine; Roza, Bartira De’ Aguiar

    2015-01-01

    OBJECTIVE To evaluate the viability of a professional specialist in intra-hospital committees of organ and tissue donation for transplantation. METHODS Epidemiological, retrospective and cross-sectional study (2003-2011 and 2008-2012), which was performed using organ donation for transplants data in the state of Sao Paulo, Southeastern Brazil. Nine hospitals were evaluated (hospitals 1 to 9). Logistic regression was used to evaluate the differences in the number of brain death referrals and actual donors (dependent variables) after the professional specialist started work (independent variable) at the intra-hospital committee of organ and tissue donation for transplantation. To evaluate the hospital invoicing, the hourly wage of the doctor and registered nurse, according to the legislation of the Consolidation of Labor Laws, were calculated, as were the investment return and the time elapsed to do so. RESULTS Following the nursing specialist commencement on the committee, brain death referrals and the number of actual donors increased at hospital 2 (4.17 and 1.52, respectively). At hospital 7, the number of actual donors also increased from 0.005 to 1.54. In addition, after the nurse started working, hospital revenues increased by 190.0% (ranging 40.0% to 1.955%). The monthly cost for the nurse working 20 hours was US$397.97 while the doctor would cost US$3,526.67. The return on investment was 275% over the short term (0.36 years). CONCLUSIONS This paper showed that including a professional specialist in intra-hospital committees for organ and tissue donation for transplantation proved to be cost-effective. Further economic research in the area could contribute to the efficient public policy implementation of this organ and tissue harvesting model. PMID:26487290

  6. Intra-hospital organ and tissue donation coordination project: cost-effectiveness and social benefits

    Directory of Open Access Journals (Sweden)

    Vanessa Silva e Silva

    2015-01-01

    Full Text Available OBJECTIVE To evaluate the viability of a professional specialist in intra-hospital committees of organ and tissue donation for transplantation.METHODS Epidemiological, retrospective and cross-sectional study (2003-2011 and 2008-2012, which was performed using organ donation for transplants data in the state of Sao Paulo, Southeastern Brazil. Nine hospitals were evaluated (hospitals 1 to 9. Logistic regression was used to evaluate the differences in the number of brain death referrals and actual donors (dependent variables after the professional specialist started work (independent variable at the intra-hospital committee of organ and tissue donation for transplantation. To evaluate the hospital invoicing, the hourly wage of the doctor and registered nurse, according to the legislation of the Consolidation of Labor Laws, were calculated, as were the investment return and the time elapsed to do so.RESULTS Following the nursing specialist commencement on the committee, brain death referrals and the number of actual donors increased at hospital 2 (4.17 and 1.52, respectively. At hospital 7, the number of actual donors also increased from 0.005 to 1.54. In addition, after the nurse started working, hospital revenues increased by 190.0% (ranging 40.0% to 1.955%. The monthly cost for the nurse working 20 hours was US$397.97 while the doctor would cost US$3,526.67. The return on investment was 275% over the short term (0.36 years.CONCLUSIONS This paper showed that including a professional specialist in intra-hospital committees for organ and tissue donation for transplantation proved to be cost-effective. Further economic research in the area could contribute to the efficient public policy implementation of this organ and tissue harvesting model.

  7. Investigating Variations in Gameplay: Cognitive Implications

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    Kamran Sedig

    2015-01-01

    Full Text Available There is increasing interest in creating computer games for learning, problem solving, and other high-level cognitive activities. When investigating whether gameplay is conducive to such activities, gameplay is often studied as a whole. As a result, cognitive implications can be linked to the game but not to its structural elements. Given that gameplay arises from interaction between the player and the game, it is the structural components of interaction that should be investigated to better understand the design of gameplay. Furthermore, minor variations in the components of interaction can have significant cognitive implications. However, such variation has not been studied yet. Thus, to gain a better understanding of how we can study the effect of interaction on the cognitive aspect of gameplay, we conducted an exploratory investigation of two computer games. These games were isomorphic at a deep level and only had one minor difference in the structure of their interaction. Volunteers played these games and discussed the cognitive processes that emerged. In one game, they primarily engaged in planning, but in the other game they primarily engaged in visualizing. This paper discusses the results of our investigation as well as its implications for the design of computer games.

  8. Intra-Hospital Committee for Donation of Organs and Tissues for Transplant: ethical issues

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    Josiane Cappellaro

    2015-02-01

    Full Text Available The objective of this study was to demonstrate ethical aspects involved in the donation, collection and transplantation of organs and tissues through the experiences of workers in an intra-hospital committee for donation of organs and tissues for transplant. Exploratory qualitative research developed with eleven health workers. Data collection was performed at a university hospital in Pelotas, RS, Brazil, in the period of January-March 2010, through interviews. Data analysis resulted in the following categories: understanding of brain death diagnosis as an ethical issue; and, ethical issues experienced by workers in the relationship established with the family. It was concluded that such situations instigate workers to reflect on their attitudes, values, and their role as a health team member and protector of lives.

  9. Medical complications of intra-hospital patient transports: implications for architectural design and research.

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    Ulrich, Roger S; Zhu, Xuemei

    2007-01-01

    Literature on healthcare architecture and evidence-based design has rarely considered explicitly that patient outcomes may be worsened by intra-hospital transport (IHT), which is defined as transport of patients within the hospital. The article focuses on the effects of IHTs on patient complications and outcomes, and the implications of such impacts for designing safer, better hospitals. A review of 22 scientific studies indicates that IHTs are subject to a wide range of complications, many of which occur frequently and have distinctly detrimental effects on patient stability and outcomes. The research suggests that higher patient acuity and longer transport durations are associated with more frequent and serious IHT-related complications and outcome effects. It appears no rigorous research has compared different hospital designs and layouts with respect to having possibly differential effects on transport-related complications and worsened outcomes. Nonetheless, certain design implications can be extracted from the existing research literature, including the importance of minimizing transport delays due to restricted space and congestion, and creating layouts that shorten IHT times for high-acuity patients. Limited evidence raises the possibility that elevator-dependent vertical building layouts may increase susceptibility to transport delays that worsen complications. The strong evidence indicating that IHTs trigger complications and worsen outcomes suggests a powerful justification for adopting acuity-adaptable rooms and care models that substantially reduce transports. A program of studies is outlined to address gaps in knowledge.Key WordsPatient transports, transports within hospitals, patient safety, evidence-based design, hospital design, healthcare architecture, intra-hospital transport complications, acuity-adaptable care, elevators, outcomes.

  10. Establishment of a network-based intra-hospital virtual cancer biobank.

    Science.gov (United States)

    Zhang, Lianhai; Wu, Xiaojiang; Hu, Ying; Wang, Xiaohong; He, Zhonghu; Xie, Yuntao; Pan, Kaifeng; Wang, Ning; Dong, Zhihua; Zhang, Lei; Ji, Jiafu

    2015-02-01

    There is a growing interest in integrating biomaterial repositories into larger infrastructures in order to meet research demands. However, even for a single hospital or institute, where both population-based and multiple disease-based biobanks have existed for a long time, the integration of existing separate biobanks into a virtual cancer biobank is still challenging. The guidelines and procedures for biobanking are varied and not universally enforced or followed in separate biobanks. Within the last 2 years, we initiated a project to establish a centralized biobank facility in a common storage environment. Analyzing the challenges and interests of stakeholders for the biobanks, a working group comprised of representatives from the central and separate banks, ethic committees, and research administration offices reached an agreement to implement a central facility by following the ISBER best practices for biobanking, and including regular project reviews by the ethical and scientific boards. Furthermore, by implementing a modified minimum information system with biobank data sharing, a network based intra-hospital virtual cancer bank was established to facilitate sharing information of samples held by separate banks. Meanwhile, this virtual biobank network, which has integrated patient information from hospital health care systems, will gradually integrate follow-up information from the cancer registry office and data from epidemiology studies, providing controlled access for sample providers and resource users. In the future, this infrastructure designed for a single hospital may be helpful for building a broader virtual network for data and specimen exchanges.

  11. Multiple intra-hospital transports during relocation to a new critical care unit.

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    O'Leary, R-A; Conrick-Martin, I; O'Loughlin, C; Curran, M-R; Marsh, B

    2017-11-01

    Intra-hospital transport (IHT) of critically ill patients is associated with morbidity and mortality. Mass transfer of patients, as happens with unit relocation, is poorly described. We outline the process and adverse events associated with the relocation of a critical care unit. Extensive planning of the relocation targeted patient and equipment transfer, reduction in clinical pressure prior to the event and patient care during the relocation phase. The setting was a 30-bed, tertiary referral, combined medical and surgical critical care unit, located in a 570-bed hospital that serves as the national referral centre for cardiothoracic surgery and spinal injuries. All stakeholders relevant to the critical care unit relocation were involved, including nursing and medical staff, porters, information technology services, laboratory staff, project development managers, pharmacy staff and building contractors. Mortality at discharge from critical care unit and discharge from hospital were the main outcome measures. A wide range of adverse events were prospectively recorded, as were transfer times. Twenty-one patients underwent IHT, with a median transfer time of 10 min. Two transfers were complicated by equipment failure and three patients experienced an episode of hypotension requiring intervention. There were no cases of central venous or arterial catheter or endotracheal tube dislodgement, and hospital mortality at 30 days was 14%. Although IHT is associated with morbidity and mortality, careful logistical planning allows for efficient transfer with low complication rates.

  12. Intra-Hospital Outcomes in ST Elevation Myocardial Infarction: Comparison of Diabetic and Non-Diabetic Patients

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    Toba Kazemi

    2015-12-01

    Full Text Available We read the interesting article entitled “the Effect of Diabetes Mellitus on Short Term Mortality and Morbidity after Isolated Coronary Artery Bypass Grafting Surgery” (1. We performed a study on intra-hospital complications in diabetic and non-diabetic patients with Acute Myocardial Infarction (AMI in Birjand, east of Iran in 2012. In our study, 479 patients with AMI (243 diabetics and 236 non-diabetics were assessed. The subjects’ mean age was 61.95 ± 13.18 years. Assessment of intra-hospital complications in the two groups revealed that recurrent angina and mortality were significantly higher in the diabetics compared to the non-diabetics (52.5% vs. 39.3%, P = 0.009; 11.2% vs. 2.6%, P = 0.012, respectively. Besides, the mean Ejection Fraction (EF was lower in the diabetics in comparison to the non-diabetics (45.26 ± 11.37% vs. 49.98 ± 10.39%, P = 0.014. Moreover, the incidence rates of intra-hospital mortality and heart failure were higher in the diabetics with AMI. This can be due to the higher prevalence of the associated risk factors, such as hypertension, dyslipidemia, and hyperglycemia, in diabetic patients and their effects on the heart. Hyperglycemia occurring after AMI is a strong and independent prognostic marker of post-MI complications. Stress, which occurs following AMI, increases insulin resistance and hyperglycemia and decreases glucose tolerance. Un-controlled diabetes in patients having AMI is accompanied by an unfavorable prognosis and may increase the risk of life-threatening complications (2. The increased risk of complications can be a possible explanation for the increase in intra-hospital mortality after AMI is diabetic patients. Various studies have indicated that initial hyperglycemia associated with failure of ST segment resolution after streptokinase infusion is followed by more extensive infarction revealed in Single-Photon Emission Computerized Tomography (SPECT, less blood flow in coronary arteries in

  13. Antenatal treatment with corticosteroids for preterm neonates: impact on the incidence of respiratory distress syndrome and intra-hospital mortality

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    Joice Fabíola Meneguel

    Full Text Available CONTEXT: Although the benefits of antenatal corticosteroids have been widely demonstrated in other countries, there are few studies among Brazilian newborn infants. OBJECTIVE: To evaluate the effectiveness of antenatal corticosteroids on the incidence of respiratory distress syndrome and intra-hospital mortality among neonates with a gestational age of less than 34 weeks. TYPE OF STUDY: Cross-sectional. SETTING: A tertiary-care hospital. PARTICIPANTS: Neonates exposed to any dose of antenatal corticosteroids for fetal maturation up to 7 days before delivery, and newborns paired by sex, birth weight, gestational age and time of birth that were not exposed to antenatal corticosteroids. The sample obtained consisted of 205 exposed newborns, 205 non-exposed and 39 newborns exposed to antenatal corticosteroids for whom it was not possible to find an unexposed pair. PROCEDURES: Analysis of maternal and newborn records. MAIN MEASUREMENTS: The primary clinical outcomes for the two groups were compared: the incidence of respiratory distress syndrome and intra-hospital mortality; as well as secondary outcomes related to neonatal morbidity. RESULTS: Antenatal corticosteroids reduced the occurrence of respiratory distress syndrome (OR: 0.33; 95% CI: 0.21-0.51 and the protective effect persisted when adjusted for weight, gestational age and the presence of asphyxia (adjusted OR: 0.27; 95% CI: 0.17-0.43. The protective effect could also be detected through the reduction in the need for and number of doses of exogenous surfactant utilized and the number of days of mechanical ventilation needed for the newborns exposed to antenatal corticosteroids. Their use also reduced the occurrence of intra-hospital deaths (OR: 0.51: 95% CI: 0.38-0.82. However, when adjusted for weight, gestational age, presence of prenatal asphyxia, respiratory distress syndrome, necrotizing enterocolitis and use of mechanical ventilation, the antenatal corticosteroids did not maintain the

  14. Predictive score for clinical complications during intra-hospital transports of infants treated in a neonatal unit

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    Anna Luiza Pires Vieira

    2011-01-01

    Full Text Available OBJECTIVE: To develop and validate a predictive score for clinical complications during intra-hospital transport of infants treated in neonatal units. METHODS: This was a cross-sectional study nested in a prospective cohort of infants transported within a public university hospital from January 2001 to December 2008. Transports during even (n=301 and odd (n = 394 years were compared to develop and validate a predictive score. The points attributed to each score variable were derived from multiple logistic regression analysis. The predictive performance and the score calibration were analyzed by a receiver operating characteristic (ROC curve and Hosmer-Lemeshow test, respectively. RESULTS: Infants with a mean gestational age of 35 + 4 weeks and a birth weight of 2457 + 841 g were studied. In the derivation cohort, clinical complications occurred in 74 (24.6% transports. Logistic regression analysis identified five variables associated with these complications and assigned corresponding point values: gestation at birth [34 weeks (2 pts]; pre-transport temperature [37°C(3pts; 36.3-37.0°C (2 pts]; underlying pathological condition [CNS malformation (4 pts; other (2 pts]; transport destination [surgery (5 pts; magnetic resonance or computed tomography imaging (3 pts; other (2 pts]; and pre-transport respiratory support [mechanical ventilation (8 pts; supplemental oxygen (7 pts; no oxygen (2 pts]. For the derivation and validation cohorts, the areas under the ROC curve were 0.770 and 0.712, respectively. Expected and observed frequencies of complications were similar between the two cohorts. CONCLUSION: The predictive score developed and validated in this study presented adequate discriminative power and calibration. This score can help identify infants at risk of clinical complications during intra-hospital transports.

  15. Tiger hair morphology and its variations for wildlife forensic investigation

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    Thitika Kitpipit

    2013-11-01

    Full Text Available Tiger population has dramatically decreased due to illegal consumption and commercialisation of their body parts. Frequently, hair samples are the only evidence found in the crime scene. Thus, they play an important role in species identification for wildlife forensic investigation. In this study, we provide the first in-depth report on a variety of qualitative and quantitative characteristics of tiger guard hairs (24 hairs per individual from four individuals. The proposed method could reduce subjectivity of expert opinions on species identification based on hair morphology. Variations in 23 hair morphological characteristics were quantified at three levels: hair section, body region, and intra-species. The results indicate statistically significant variations in most morphological characteristics in all levels. Intra-species variations of four variables, namely hair length, hair index, scale separation and scale pattern, were low. Therefore, identification of tiger hairs using these multiple features in combination with other characteristics with high inter-species variations (e.g. medulla type should bring about objective and accurate tiger hair identification. The method used should serve as a guideline and be further applied to other species to establish a wildlife hair morphology database. Statistical models could then be constructed to distinguish species and provide evidential values in terms of likelihood ratios.

  16. SANS contrast-variation for investigating the microstructure of nanoparticles

    International Nuclear Information System (INIS)

    Bartlett, J.R.; Woolfrey, J.L.

    1999-01-01

    Over the past two decades, the demand for ceramics with high purity, homogeneity and well-controlled bulk and interfacial properties has led to a significant interest in sol-gel technology, often using alkoxide precursors. An inherent advantage of the sol-gel process is that it permits the preparation of multicomponent nanoparticles, with mixing of the elements on a molecular, or at least nanometre, scale. During the preparation of such multi-component nanoparticles, it is essential to promote controlled co-hydrolysis of mixed precursor alkoxides, to obtain a homogeneous distribution of the components. However, this is not always possible due to the constraints of chemistry and cost. Thus, techniques capable of investigating homogeneity and nanoscale segregation of components in the bulk, or at interfaces, during the processing of multicomponent nanoparticles are extremely important in modern Materials Science. Small-angle neutron scattering (SANS) is a powerful technique used in Materials Science for probing microstructural features, such as particle and pore size, or compositional variations, of materials, on lengths scale between ∼ 1 nm and 1 μm. The SANS contrast-variation method is particularly useful for investigating nanoscale segregation at interfaces and/or within the particles. In SANS contrast-variation experiments involving nanoparticles dispersed in a continuous aqueous phase, the scattering length of the continuous phase is adjusted by varying the D 2 O/H 2 O volume ratios, to determine the ratio at which the minimum in the scattering intensity is observed. (authors)

  17. Intra-Hospital Transport of Patients on Non-Invasive Ventilation: Review, Analysis, and Key Practical Recommendations by the International NIV Committee

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    Annia Schreiber

    2017-12-01

    Full Text Available Intra-hospital transport is often needed for diagnostic and therapeutic procedures that cannot be performed at the bedside. However, moving patients from the safe environment of an Intensive Care Unit (ICU can lead to a variety of complications and adverse events, the risk is even higher in ventilated patients. This review is intended as a guide on how to prevent and avoid these adverse events during intra-hospital transport of patients on non-invasive ventilation (NIV. Greater attention should be paid to NIV indications and the selection of the patients to be transported. Detailed planning, preparation, and communication between the ward of origin and destination site, appropriate equipment, skilled staff, and continuous monitoring are the key major determinants of success in transporting critically ill patients on NIV. These points are discussed and analyzed in detail.

  18. Pre-hospital and intra-hospital temporal intervals in patients requiring emergent trauma craniotomy. A 6-year observational study in a level 1 trauma center.

    Science.gov (United States)

    De Vloo, Philippe; Nijs, Stefaan; Verelst, Sandra; van Loon, Johannes; Depreitere, Bart

    2018-03-13

    According to level 2 evidence, earlier evacuation of acute subdural or epidural hematomas necessitating surgery is associated with better outcome. Hence, guidelines recommend performing these procedures "immediately". Literature on extent and causes of pre- and intra-hospital intervals in trauma patients requiring emergent craniotomies is almost completely lacking. Studies delineating and refining the interval before thrombolytic agent administration in ischemic stroke have dramatically reduced the "door-to-needle time". A similar exercise for "trauma-to-decompression time" might result in comparable reductions. We aim to map intervals in emergent trauma craniotomies in our Level 1 Trauma Center, screen for associated factors, and propose possible ways to reduce these intervals. We analyzed patients who were primarily referred (1R; n=45) and secondarily referred (after CT imaging in a community hospital; 2R; n=22) to our emergency department (ED), and underwent emergent trauma craniotomies between 2010 and 2016. Median pre-hospital interval (between emergency call (EC) and arrival at the ED) was 42min for 1R patients. Median intra-hospital interval (between initial ED arrival and skin incision (SI)) was 140min and 268min for 1R and 2R patients, respectively. In 1R patients, ED-SI interval was positively correlated with GCS (ρ=.49; Ppre-hospital and intra-hospital measures to improve performance. This is the first report on EC-SI interval in emergent trauma craniotomy, with a median of 174min and >297min for 1R and 2R patients, respectively, in our center. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Investigation on generalized Variational Nodal Methods for heterogeneous nodes

    International Nuclear Information System (INIS)

    Wang, Yongping; Wu, Hongchun; Li, Yunzhao; Cao, Liangzhi; Shen, Wei

    2017-01-01

    Highlights: • We developed two heterogeneous nodal methods based on the Variational Nodal Method. • Four problems were solved to evaluate the two heterogeneous nodal methods. • The function expansion method is good at treating continuous-changing heterogeneity. • The finite sub-element method is good at treating discontinuous-changing heterogeneity. - Abstract: The Variational Nodal Method (VNM) is generalized for heterogeneous nodes and applied to four kinds of problems including Molten Salt Reactor (MSR) core problem with continuous cross section profile, Pressurized Water Reactor (PWR) control rod cusping effect problem, PWR whole-core pin-by-pin problem, and heterogeneous PWR core problem without fuel-coolant homogenization in each pin cell. Two approaches have been investigated for the treatment of the nodal heterogeneity in this paper. To concentrate on spatial heterogeneity, diffusion approximation was adopted for the angular variable in neutron transport equation. To provide demonstrative numerical results, the codes in this paper were developed in slab geometry. The first method, named as function expansion (FE) method, expands nodal flux by orthogonal polynomials and the nodal cross sections are also expressed as spatial depended functions. The second path, named as finite sub-element (FS) method, takes advantage of the finite-element method by dividing each node into numbers of homogeneous sub-elements and expanding nodal flux into the combination of linear sub-element trial functions. Numerical tests have been carried out to evaluate the ability of the two nodal (coarse-mesh) heterogeneous VNMs by comparing with the fine-mesh homogeneous VNM. It has been demonstrated that both heterogeneous approaches can handle heterogeneous nodes. The FE method is good at continuous-changing heterogeneity as in the MSR core problem, while the FS method is good at discontinuous-changing heterogeneity such as the PWR pin-by-pin problem and heterogeneous PWR core

  20. Investigation of pH variation of blood during peloidotherapy

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    Surdu Traian-Virgiliu

    2012-11-01

    Full Text Available The main aim of the study is to evaluate the variation of acid-base balance of human body during peloidotherapy. The secondary objectiv is balneal safetyness for the patient suffering of joint degenerative deaseases and post-traumatic sequelles of the limbs, undergoing mud therapy. This paper work presents only the results obtained on pH variations. Materials and methods. The study plot was composed by forty three patients undergoing mud therapy for rehabilitation in Techirghiol Balneal and Rehabilitation Sanatorium. Daily therapeutic intervention consists in: thermoneutral bath (alternativelly mud bath and salt bath, kinetotherapy, massage and electrotherapy. Proofs prelevations (capilary blood were performed in four moments of the cure: at the bigining of the cure, immediatly after first balneal application, at twenty four hours after first application and at the end of the cure of ten balneal application. Blood determinations were made using CCX Nova Biomedical 6 analyser for critical care. Results obtained were interpretated in corelation with the results of VIASAN 317/2004 study upon variations of biochemical composition of mud after therapeutic use. In order to use results of VIASAN study we asked and we received aproval from the owner and incumbent of the study, Techirghiol Balneal and Rehabilitation Sanatorium. All patients get to know about the rithm of blood prelevation and possibility of results publication and they signed the informed consent. Statistic analysis were made with the soft SPSS 12.0 upon witch Constanţa Ovidius University holds the licence of using. Rezults. Variations of blood pH in the four moments of cure were within physiological limits. They were statistically insignificant with one exception: immediatly after first salt bath application pH increased statistic significant but within physiological limits (p=0.02<0.05. Conclusions. During peloidotherapy the acidity of blood masured throught pH, variates within the

  1. an investigation into the applicability of natural load variation ...

    African Journals Online (AJOL)

    The present work explores the potentials of natural load variation scheme as a low cost option that is capable of estimating the actual yield of PV modules. Essentially, the scheme consists of a firmware controlling the switching of a number of resistors(loads) connected in parallel. By looping through the resistors in parallel, ...

  2. The investigation of foxe1 variations in papillary thyroid carcinoma

    Science.gov (United States)

    Somuncu, Erkan; Karatas, Adem; Ferahman, Sina; Saygili, Neslihan; Yilmaz, Eren; Ozturk, Oguz; Kapan, Metin

    2015-01-01

    Background: Recent reports indicated that incidence of thyroid carcinoma is increasing throughout the worldwide. The aim of our study was to determine a possible relationship between Forkhead box E1 (FOXE1) gene variants and histopathological features of papillary thyroid carcinoma. Methods: FOXE1 gene variations; rs894673, rs1867277 and rs3758249 were analyzed in 57 Papillary thyroid carcinoma patients and 51 age matched healthy control subjects. Restriction fragment length polymorphism (RFLP) technique was used to specifically detect the variations. Results: There was a significant difference in the distribution of rs894673 genotypes in Papillary thyroid carcinoma cases (P=0.01). AA genotype presence of rs1867277 was more significantly associated with several histopathological parameters such as focal and diffuse capsular invasion, lymphatic invasion, P3 with P4 tumor grade and surgical margins. AA genotype presence in rs1867277 variation was significantly associated with the classical variant which is subtype of papillary thyroid carcinoma. Furthermore, the presence of the allel A was found to be related with lymph node invasion risk by 2.46 fold, capsular invasion risk by 2.97 fold, and pT3 with pT4 pathological stage risk by 4.13 fold and the presence of allele A in rs1867277 was significantly associated with classic variants. The presence of allele A in rs1867277 was more significantly associated with several histopathological parameters in classic variant in papillary thyroid carcinoma cases such as, the presence of the A allele was found relationship with lymph node invasion risk by 2.0 fold, capsular invasion risk by 2.39 fold , and pT3 with pT4 pathological stage risk by 3.57 fold. In addition, AATT, AAAA and GATT haplotypes (rs1867277 and rs894673) were evaluated for association with papillary thyroid carcinoma cases. Our results indicate that the significant difference according to two-allele haplotype distribution between papillary thyroid carcinoma

  3. Proteogenomic Investigation of Strain Variation in Clinical Mycobacterium tuberculosis Isolates

    KAUST Repository

    Heunis, Tiaan

    2017-08-18

    Mycobacterium tuberculosis consists of a large number of different strains that display unique virulence characteristics. Whole-genome sequencing has revealed substantial genetic diversity among clinical M. tuberculosis isolates, and elucidating the phenotypic variation encoded by this genetic diversity will be of utmost importance to fully understand M. tuberculosis biology and pathogenicity. In this study we integrated whole-genome sequencing and mass spectrometry (GeLC-MS/MS) to reveal strain-specific characteristics in the proteomes of two clinical M. tuberculosis Latin American-Mediterranean isolates. Using this approach we identified 59 peptides containing single amino acid variants, which covered ~9% of all total coding nonsynonymous single nucleotide variants detected by whole-genome sequencing. Furthermore, we identified 29 distinct peptides that mapped to a hypothetical protein not present in the M. tuberculosis H37Rv reference proteome. Here we provide evidence for the expression of this protein in the clinical M. tuberculosis SAWC3651 isolate. The strain-specific databases enabled confirmation of genomic differences (i.e. large genomic regions of difference and nonsynonymous single nucleotide variants) in these two clinical M. tuberculosis isolates and allowed strain differentiation at the proteome level. Our results contribute to the growing field of clinical microbial proteogenomics and can improve our understanding of phenotypic variation in clinical M. tuberculosis isolates.

  4. Investigation on Genetic Variation of Iran Watermelon Accession

    Directory of Open Access Journals (Sweden)

    majid reza kiyani

    2009-06-01

    Full Text Available In order to determine of genetic variation in germplasm of 120 watermelon accessions, a field trial conducted at agricultural and natural resource research center of khorasan . These Accessions with four commercial cultivars as control were planted in agnomental design with six replications. 15 quantitative morphological traits were measured and some statistical parameter and analysis include of Mean, Coefficient variance, cluster analysis, correlation regression coefficients were determine for this traits. yield, Sugar percent , time between flowering and ripping, fruit length, fruit width, fruit mass to fruit weight ratio , fruit skin to fruit weight ratio , seed weight to fruit weight ratio , 100 seed weight , seed length , seed diameter , seed width were the most useful traits for identifying of genotypes from each other. A one side analysis of variance was performed for different regions genetic diversity detection, which indicated a significant difference between regions for all traits except fruit Ph and fruit skin thickness. Cluster analysis divided genotypes into eight groups based on quantitative data. Correlation analysis between traits showed a significant relation between yield and all traits except fruit ph, time to flowering and seed fruit length.

  5. Latitudinal and Seasonal Investigations of Storm-Time TEC Variation

    Science.gov (United States)

    Adimula, I. A.; Oladipo, O. A.; Adebiyi, S. J.

    2016-07-01

    The ionosphere responds markedly and unpredictably to varying magnetospheric energy inputs caused by solar disturbances on the geospace. Knowledge of the impact of the space weather events on the ionosphere is important to assess the environmental effect on the operations of ground- and space-based technologies. Thus, global positioning system (GPS) measurements from the international GNSS service (IGS) database were used to investigate the ionospheric response to 56 geomagnetic storm events at six different latitudes comprising the northern and southern hemispheres in the Afro-European sector. Statistical distributions of total electron content (TEC) response show that during the main phase of the storms, enhancement of TEC is more pronounced in most of the seasons, regardless of the latitude and hemisphere. However, a strong seasonal dependence appears in the TEC response during the recovery phase. Depletion of TEC is majorly observed at the high latitude stations, and its appearance at lower latitudes is seasonally dependent. In summer hemisphere, the depletion of TEC is more pronounced in nearly all the latitudinal bands. In winter hemisphere, enhancement as well as depletion of TEC is observed over the high latitude, while enhancement is majorly observed over the mid and low latitudes. In equinoxes, the storm-time TEC distribution shows a fairly consistent characteristic with the summer distribution, particularly in the northern hemisphere.

  6. Investigation of switching frequency variations and EMI properties in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard

    2009-01-01

    for its variation. Knowledge of switching frequency variations is of great importance with respect to electromagnetic interference (EMI). This paper will investigate, whether the switching frequency is depended on modulation index and audio reference frequency. Validation is done using simulations......, and the results are compared with measurements performed on a 50 W prototype amplifier. The switching frequency is tracked through accurate spectrum measurements, and very good compliance with simulation results are observed....

  7. Using of the variational principle for investigation of the supersymmetry models

    International Nuclear Information System (INIS)

    Krasnikov, N.V.

    1985-01-01

    The variational principle is used for investigation of possible spontaneous breaking of supersymmetry. It is shown that if supersymmetry in the generalized Wess-Zumino model is not broken on the classical level, it is neither broken as well with account for quantum corrections

  8. Investigation of Copy Number Variation in Children with Conotruncal Heart Defects

    Directory of Open Access Journals (Sweden)

    Carla Marques Rondon Campos

    2015-01-01

    Full Text Available Background: Congenital heart defects (CHD are the most prevalent group of structural abnormalities at birth and one of the main causes of infant morbidity and mortality. Studies have shown a contribution of the copy number variation in the genesis of cardiac malformations. Objectives: Investigate gene copy number variation (CNV in children with conotruncal heart defect. Methods: Multiplex ligation-dependent probe amplification (MLPA was performed in 39 patients with conotruncal heart defect. Clinical and laboratory assessments were conducted in all patients. The parents of the probands who presented abnormal findings were also investigated. Results: Gene copy number variation was detected in 7/39 patients: 22q11.2 deletion, 22q11.2 duplication, 15q11.2 duplication, 20p12.2 duplication, 19p deletion, 15q and 8p23.2 duplication with 10p12.31 duplication. The clinical characteristics were consistent with those reported in the literature associated with the encountered microdeletion/microduplication. None of these changes was inherited from the parents. Conclusions: Our results demonstrate that the technique of MLPA is useful in the investigation of microdeletions and microduplications in conotruncal congenital heart defects. Early diagnosis of the copy number variation in patients with congenital heart defect assists in the prevention of morbidity and decreased mortality in these patients.

  9. Investigation of Copy Number Variation in Children with Conotruncal Heart Defects

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Carla Marques Rondon, E-mail: carlamcampos@uol.com.br [Universidade Federal de Mato Grosso, Cuiabá, MT (Brazil); Zanardo, Evelin Aline; Dutra, Roberta Lelis [Departamento de Patologia - Laboratório de Citogenômica - LIM 03 - Universidade de São Paulo, São Paulo, SP (Brazil); Kulikowski, Leslie Domenici [Universidade de São Paulo, São Paulo, SP (Brazil); Departamento de Patologia - Laboratório de Citogenômica - LIM 03 - Universidade de São Paulo, São Paulo, SP (Brazil); Kim, Chong Ae [Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-01-15

    Congenital heart defects (CHD) are the most prevalent group of structural abnormalities at birth and one of the main causes of infant morbidity and mortality. Studies have shown a contribution of the copy number variation in the genesis of cardiac malformations. Investigate gene copy number variation (CNV) in children with conotruncal heart defect. Multiplex ligation-dependent probe amplification (MLPA) was performed in 39 patients with conotruncal heart defect. Clinical and laboratory assessments were conducted in all patients. The parents of the probands who presented abnormal findings were also investigated. Gene copy number variation was detected in 7/39 patients: 22q11.2 deletion, 22q11.2 duplication, 15q11.2 duplication, 20p12.2 duplication, 19p deletion, 15q and 8p23.2 duplication with 10p12.31 duplication. The clinical characteristics were consistent with those reported in the literature associated with the encountered microdeletion/microduplication. None of these changes was inherited from the parents. Our results demonstrate that the technique of MLPA is useful in the investigation of microdeletions and microduplications in conotruncal congenital heart defects. Early diagnosis of the copy number variation in patients with congenital heart defect assists in the prevention of morbidity and decreased mortality in these patients.

  10. Investigating the effect of lateral viscosity variations in the Earth's mantle

    Science.gov (United States)

    O'Farrell, K. A.; Lithgow-Bertelloni, C. R.

    2015-12-01

    Seismic tomography can be used to investigate radial viscosity variations on instantaneous flow models by predicting the global geoid and comparing with the observed geoid. This method is one of many that has been used to constrain viscosity structure in the Earth's mantle in the last few decades. Using the 3D mantle convection model, Stag-YY (e.g., Hernlund and Tackley, 2008), we are further able to explore the effect of lateral variations in viscosity in addition to the radial variations. Examining over 50 tomographic models we found notable differences by comparing a synthetically produced geoid with the observed geoid. Comparing S- and P-wave tomographic models, the S-wave models provided a better fit to the observed geoid. Using this large suite of 50 tomographic models, we have been able to constrain the radial viscosity structure of the Earth. We found that two types of viscosity profiles yielded equally good fits. A viscosity profile with a low transition zone viscosity and a lower mantle viscosity equal to the upper mantle, or a profile with a large lower mantle viscosity and a transition zone viscosity similar to the upper mantle. Using the set of radial viscosity profiles that gave the best fit to the observed geoid, we can explore a range of lateral viscosity variations and see how they affect the different types of tomographic models. Improving on previous studies of lateral viscosity variations (e.g. Ghosh, Becker and Zhong, 2010), we systematically explore a large range of tomographic models and density-velocity conversion factors. We explore which type of tomographic model (S- or P- wave) is more strongly affected by lateral viscosity variations, as well as the effect on isotropic and anisotropic models. We constrain the strength of lateral viscosity variations necessary to produce a high correlation between observed and predicted geoid anomalies. We will discuss the wavelength of flow that is most affected by the lateral viscosity variations

  11. Investigating variations in implementation fidelity of an organizational-level occupational health intervention.

    Science.gov (United States)

    Augustsson, Hanna; von Thiele Schwarz, Ulrica; Stenfors-Hayes, Terese; Hasson, Henna

    2015-06-01

    The workplace has been suggested as an important arena for health promotion, but little is known about how the organizational setting influences the implementation of interventions. The aims of this study are to evaluate implementation fidelity in an organizational-level occupational health intervention and to investigate possible explanations for variations in fidelity between intervention units. The intervention consisted of an integration of health promotion, occupational health and safety, and a system for continuous improvements (Kaizen) and was conducted in a quasi-experimental design at a Swedish hospital. Implementation fidelity was evaluated with the Conceptual Framework for Implementation Fidelity and implementation factors used to investigate variations in fidelity with the Framework for Evaluating Organizational-level Interventions. A multi-method approach including interviews, Kaizen notes, and questionnaires was applied. Implementation fidelity differed between units even though the intervention was introduced and supported in the same way. Important differences in all elements proposed in the model for evaluating organizational-level interventions, i.e., context, intervention, and mental models, were found to explain the differences in fidelity. Implementation strategies may need to be adapted depending on the local context. Implementation fidelity, as well as pre-intervention implementation elements, is likely to affect the implementation success and needs to be assessed in intervention research. The high variation in fidelity across the units indicates the need for adjustments to the type of designs used to assess the effects of interventions. Thus, rather than using designs that aim to control variation, it may be necessary to use those that aim at exploring and explaining variation, such as adapted study designs.

  12. Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk

    DEFF Research Database (Denmark)

    Olsen, Nils; Mandea, M.

    2007-01-01

    Observatory monthly means provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, the uneven distribution of the present observatory network makes it difficult to determine the global field change pattern. Recently, we have developed...... an approach to extract satellite monthly means at a regular network of "virtual observatories" at 400 km altitude, based on CHAMP magnetic measurements. Using monthly means for 2001-2005 from those "virtual observatories" we investigate the space-time structure of the short-period variation of the Earth......'s magnetic field by means of a Spherical Harmonic Expansion, followed by a separation into external (magnetospheric) and internal part. This allows, for the first time, to study the secular variation globally and directly from satellite magnetic data. Analyzing the time series of the magnetic field...

  13. Geographic, demographic, and socioeconomic variations in the investigation and management of coronary heart disease in Scotland.

    Science.gov (United States)

    MacLeod, M C; Finlayson, A R; Pell, J P; Findlay, I N

    1999-03-01

    To determine whether age, sex, level of deprivation, and area of residence affect the likelihood of investigation and treatment of patients with coronary heart disease. Routine discharge data were used to identify patients admitted with acute myocardial infarction (AMI) between 1991 and 1993 inclusive. Record linkage provided the proportion undergoing angiography, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG) over the following two years. Multiple logistic regression analysis was used to determine whether age, sex, deprivation, and area of residence were independently associated with progression to investigation and revascularisation. Mainland Scotland 1991 to 1995 inclusive. Two year incidence of angiography, PTCA, and CABG. Results-36 838 patients were admitted with AMI. 4831 (13%) underwent angiography, 587 (2%) PTCA, and 1825 (5%) CABG. Women were significantly less likely to undergo angiography (p < 0.001) and CABG (p < 0.001) but more likely to undergo PTCA (p < 0.05). Older patients were less likely to undergo all three procedures (p < 0.001). Socioeconomic deprivation was associated with a reduced likelihood of both angiography and CABG (p < 0.001). There were significant geographic variations in all three modalities (p < 0.001). Variations in investigation and management were demonstrated by age, sex, geography, and socioeconomic deprivation. These are unlikely to be accounted for by differences in need; differences in clinical practice are, therefore, likely.

  14. Data-driven Inference and Investigation of Thermosphere Dynamics and Variations

    Science.gov (United States)

    Mehta, P. M.; Linares, R.

    2017-12-01

    This paper presents a methodology for data-driven inference and investigation of thermosphere dynamics and variations. The approach uses data-driven modal analysis to extract the most energetic modes of variations for neutral thermospheric species using proper orthogonal decomposition, where the time-independent modes or basis represent the dynamics and the time-depedent coefficients or amplitudes represent the model parameters. The data-driven modal analysis approach combined with sparse, discrete observations is used to infer amplitues for the dynamic modes and to calibrate the energy content of the system. In this work, two different data-types, namely the number density measurements from TIMED/GUVI and the mass density measurements from CHAMP/GRACE are simultaneously ingested for an accurate and self-consistent specification of the thermosphere. The assimilation process is achieved with a non-linear least squares solver and allows estimation/tuning of the model parameters or amplitudes rather than the driver. In this work, we use the Naval Research Lab's MSIS model to derive the most energetic modes for six different species, He, O, N2, O2, H, and N. We examine the dominant drivers of variations for helium in MSIS and observe that seasonal latitudinal variation accounts for about 80% of the dynamic energy with a strong preference of helium for the winter hemisphere. We also observe enhanced helium presence near the poles at GRACE altitudes during periods of low solar activity (Feb 2007) as previously deduced. We will also examine the storm-time response of helium derived from observations. The results are expected to be useful in tuning/calibration of the physics-based models.

  15. Investigation of dimensional variation in parts manufactured by fused deposition modeling using Gauge Repeatability and Reproducibility

    Science.gov (United States)

    Mohamed, Omar Ahmed; Hasan Masood, Syed; Lal Bhowmik, Jahar

    2018-02-01

    In the additive manufacturing (AM) market, the question is raised by industry and AM users on how reproducible and repeatable the fused deposition modeling (FDM) process is in providing good dimensional accuracy. This paper aims to investigate and evaluate the repeatability and reproducibility of the FDM process through a systematic approach to answer this frequently asked question. A case study based on the statistical gage repeatability and reproducibility (gage R&R) technique is proposed to investigate the dimensional variations in the printed parts of the FDM process. After running the simulation and analysis of the data, the FDM process capability is evaluated, which would help the industry for better understanding the performance of FDM technology.

  16. Variations in GPs' decisions to investigate suspected lung cancer: a factorial experiment using multimedia vignettes.

    Science.gov (United States)

    Sheringham, Jessica; Sequeira, Rachel; Myles, Jonathan; Hamilton, William; McDonnell, Joe; Offman, Judith; Duffy, Stephen; Raine, Rosalind

    2017-06-01

    Lung cancer survival is low and comparatively poor in the UK. Patients with symptoms suggestive of lung cancer commonly consult primary care, but it is unclear how general practitioners (GPs) distinguish which patients require further investigation. This study examined how patients' clinical and sociodemographic characteristics influence GPs' decisions to initiate lung cancer investigations. A factorial experiment was conducted among a national sample of 227 English GPs using vignettes presented as simulated consultations. A multimedia-interactive website simulated key features of consultations using actors ('patients'). GP participants made management decisions online for six 'patients', whose sociodemographic characteristics systematically varied across three levels of cancer risk. In low-risk vignettes, investigation (ie, chest X-ray ordered, computerised tomography scan or respiratory consultant referral) was not indicated; in medium-risk vignettes, investigation could be appropriate; in high-risk vignettes, investigation was definitely indicated. Each 'patient' had two lung cancer-related symptoms: one volunteered and another elicited if GPs asked. Variations in investigation likelihood were examined using multilevel logistic regression. GPs decided to investigate lung cancer in 74% (1000/1348) of vignettes. Investigation likelihood did not increase with cancer risk. Investigations were more likely when GPs requested information on symptoms that 'patients' had but did not volunteer (adjusted OR (AOR)=3.18; 95% CI 2.27 to 4.70). However, GPs omitted to seek this information in 42% (570/1348) of cases. GPs were less likely to investigate older than younger 'patients' (AOR=0.52; 95% CI 0.39 to 0.7) and black 'patients' than white (AOR=0.68; 95% CI 0.48 to 0.95). GPs were not more likely to investigate 'patients' with high-risk than low-risk cancer symptoms. Furthermore, they did not investigate everyone with the same symptoms equally. Insufficient data gathering

  17. Generalized spectrographic method of separate investigation of atmospheric, geomagnetic and extraterrestrial variations for the complex spectrum of cosmic ray extraterrestrial variation

    International Nuclear Information System (INIS)

    Dorman, L.I.

    1979-01-01

    The problem of precise determination of atmospheric variations of cosmic rays (CR) has been considered. Atmospheric CR variations under different meteorological conditions have been investigated using the spectrographic method. The several cases under study are: four stable CR components and n-4 unstable CR components are observed in one location (all data have been adjusted for pressure); all components are assumed to be unstable (pressure adjusted); spectrographic complex of unstable components at one level of observations (not adjusted for pressure and temperature) and spectrographic complex of unstable components at several levels of observation (not adjusted for pressure and temperature). Solution of the system of spectrographic equations has been obtained in the most general case. The spectrographic method has been shown to make unambiguous determinations of air column mass variations and vertical temperature section of atmosphere variations above the observation point

  18. Investigation of the daily variation in iodine and creatinine excretion in human urine

    International Nuclear Information System (INIS)

    Aabech, H.S.

    1975-08-01

    Continuing earlier investigations of the level of iodine intake in Norway, the excretion of iodine in 24-hour samples of urine over 7 days has been measured for 23 persons. Three of them collected 24-hour samples of urine during continuous periods of 21, 22 and 54 days. The main aim of the investigation was to study the diurnal variation of iodine excretion , and to correlate it with diet components when connection was suspected. To this end the persons had to keep record of the diet, especially with respect to fish and fish products. The variation from day to day of the iodine excretion was much greater than expected, and the highest values were always preceded by meals of sea-fish. Mean 24-hour iodine excretion from 13 males was 266 μg/24h (range 54-2272), from 8 females 154 μg/24h (range 58-627), and from 2 children 74 μg/24h (range 33-129). Large fluctuations were present, as indicated by standard deviations that varied from 12 to 119% of the mean. None of the persons had a mean 24-hour excretion lower than the advised minimum of 1 μg iodine/kg b w. The excretion of creatinine has also been measured, and the excretion from day to day showed large fluctuations for some of the persons. In 13 males the mean 24-hour excretion of creatinine was 1.88 gram (range 0.81-2.93), and in 8 females 1.17 gram (range 0.47-1.74). In one person, who collected urine during a period of 54 days, the mean excretion of creatinine was 1.80 gram (range 1.19-2.75). (auth.)

  19. Investigating of spatial variations of PM2.5 concentration in Suzhou using remote sensing imagery

    Science.gov (United States)

    Zhang, Shanzheng; Li, Bailiang

    2017-04-01

    Suzhou is located at the center of Yangtze Delta, suffering the air pollution from construction of mega city, industrial emission and traffic development. Particulate matter not greater than 2.5 micrometers (PM2.5) is now considered as the most important pollutants in the air in East China. For Suzhou city, some studies on PM2.5 temporal variations based on ground measurements have been conducted. However, until now, there is limited remote sensing based research to investigate the spatial pattern of PM2.5 in Suzhou. MODIS is often used to evaluate the spatial variabiilty of air quality, however, due to its low spatial resolution (250m), we have adopted China launched HJ-1 satellite with 30 m resolution of CCD sensor. Following the solar radiation S6 model and dark object atmospheric correction method (Kaufman,et al., 2000), atmospheric optical depth (AOD) was estimated. A statistical relationship has been built up between AOD and PM2.5. We have retrieved the spatial distribution of PM2.5 across Suzhou city in the winter of 2014. Results indicate that PM2.5 has the highest value in Kunshan (East of Suzhou) and Changshu and Taicang (NE of Suzhou) due to the heavy-polluted industry, while in the island of the Taihu Lake, the PM2.5 is significantly lower than other places maybe because of high deposition rate of PM2.5 over water and forest surfaces. The spatial variation also shows that traffic has less contribution to the PM2.5 generation than the industry. We believe this study will be very useful to identify the causes of local PM2.5 pollution. The findings could also benefit local management and policy making.

  20. Archaeomagnetic investigation of three Etruscan firing structures in Pisa - Data for the Italian Secular Variation Curve

    Science.gov (United States)

    Principe, Claudia; Malfatti, Jonas; Le Goff, Maxime; Grandinetti, Giuditta; Paribeni, Emanuela; Arias, Claudio

    2010-05-01

    Archaeomagnetic studies have recently undergone a significant progress in Italy, and a preliminary Italian Secular Variation Curve (Tema et al., 2007) for the last three millennia is available as a useful reference curve to compare archaeomagnetic directions from both archaeological and geological undated burnt features. However the number of well-dated and accurate archaeomagnetic directional results in our country is still far away to build a reliable dating tool, above all for times older than the 6 century BC. We present here three unpublished archaeomagnetic directional results carried out from a small Etruscan archaeological area excavated in Pisa, Tuscany (Italy). The importance of this study, a small settled area from the Orientalizzante phase (IX-VI centuries BC) with a well defined metallurgical area inside, is underlined by the fact that, at the moment, these are the only Italian directional investigations coming from a well-dated and constrained archaeological (stratigraphic) context for this time period. In particular, we sampled two different kind of structures (two firing plains and a circular oven) which were used during the iron ore reduction activities; according with different historical sources, the iron ore was probably from the Elba island deposit (Tuscany, Italy), famous for its abundance during Etruscan and Roman times. In addition we present also an updated list of our previous archaeomagnetic investigations from other Etruscan and Roman archaeological structures, in order to contribute improving the non-uniform dataset used to build the preliminary Italian Secular Variation Curve for the period BC. All the presented archaeological structures have been collected by using the modified "Thellier&Thellier" technique, while the analytical measurements have been carried out thanks to a joint collaboration between the IGG-CNR and the Paleomagnetic Laboratory of Institute the Physique du Globe de Paris (IPGP). The thermo-remanent magnetization

  1. Investigating output and energy variations and their relationship to delivery QA results using Statistical Process Control for helical tomotherapy.

    Science.gov (United States)

    Binny, Diana; Mezzenga, Emilio; Lancaster, Craig M; Trapp, Jamie V; Kairn, Tanya; Crowe, Scott B

    2017-06-01

    The aims of this study were to investigate machine beam parameters using the TomoTherapy quality assurance (TQA) tool, establish a correlation to patient delivery quality assurance results and to evaluate the relationship between energy variations detected using different TQA modules. TQA daily measurement results from two treatment machines for periods of up to 4years were acquired. Analyses of beam quality, helical and static output variations were made. Variations from planned dose were also analysed using Statistical Process Control (SPC) technique and their relationship to output trends were studied. Energy variations appeared to be one of the contributing factors to delivery output dose seen in the analysis. Ion chamber measurements were reliable indicators of energy and output variations and were linear with patient dose verifications. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  2. Investigation into Transient Flow in a Centrifugal Pump with Wear Ring Clearance Variation

    Directory of Open Access Journals (Sweden)

    Houlin Liu

    2014-04-01

    Full Text Available The leakage flow paths in the sidewall gaps of centrifugal pumps are of significant importance for numbers of effects. The paper is concerned with the transient flow in the leakage flow paths with wear ring clearance variation. For this purpose, numerical simulations of the whole pump were carried out. The grid dependence and yplus check were performed first. Additionally, experimental data of performance characteristic and pressure fluctuation inside the sidewall gap was used to validate the numerical results. The transient velocity fields inside the sidewall gaps during one blade passage period were simulated. And the leakage through the wear ring gap was obtained for all operating points investigated. To have a better idea of attenuation and propagation of pressure inside the sidewall gap, the unsteady pressure distributions in the gap were calculated. Additionally, the surfaces of the impeller were divided into four parts. The fluid force on each part was expressed as a percentage of the total radial force. Through comparing the flow fields, the pressure distributions, and the radial force between the pumps with different wear ring clearances, the effects of the wear ring clearance were discussed in detail. The results can be used to guide the optimum design of the pump sidewall gaps.

  3. Investigations on diurnal and seasonal variations of Schumann resonance intensities in the auroral region

    Directory of Open Access Journals (Sweden)

    F. Rispoli

    2007-06-01

    Full Text Available Measurements of the magnetic component of the Schumann resonance in the frequency range 6-14 Hz were performed at high latitude location (TNB Antarctica; geographic coordinates: 74.7°S, 164.1°E; geomagnetic coordinates: 80.0°S, 307.7°E; LT=UT+13; MLT=UT–8; altitude=28 m a.s.l., during the two years 1996-1997. TNB is a particularly important observation site located in a region characterised by a high electromagnetic activity in the ELF and VLF bands. Moreover its remote location in Antarctica provides the important advantage that electromagnetic background noise is not corrupted by anthropogenic noise and that the continental lightning activity is very low. The combination of low additional anthropogenic electromagnetic radiation and low atmospheric noise in this area allows detailed investigations into wave generation and amplification in the polar ionosphere and magnetosphere not possible anywhere else in the world. This paper reports the study of the magnetic power of the 8 Hz Schumann resonance mode. For both the years considered diurnal and long-term seasonal variations were observed.

  4. Investigation variation of carbon dioxide based on GOSAT data in peninsular Malaysia

    Science.gov (United States)

    Sim, C. K.; Lim, H. S.; MatJafri, M. Z.

    2015-10-01

    Carbon dioxide (CO2) is an inodorous and transparent gas, and naturally originates in our atmosphere. Due to its optical characteristics, CO2 is the most important greenhouse gas and play a key role in climate change due to an effective thermal infrared (IR) radiation absorber. Satellite observations of atmospheric carbon dioxide (CO2) can significantly improve our knowledge about the sources and sinks of CO2. The remote sensing satellite, namely Greenhouse Gases Observing Satellite (GOSAT) was employed to investigate the spatial and variations of CO2 column-averaged dry airmole fractions, denoted XCO2 over Peninsular Malaysia from January 2013 to December 2013. The analysis of CO2 in the study area shows the significant differences between northeast monsoon (NEM) and the southwest monsoon (SWM). During NEM season, cold air outbreaks from Siberia spreads to equatorial region in the form of north-easterly cold surge winds and associated with a low-level anticyclone over Southeast Asia. Inversely, air masses from the southwest contribute to long-range air pollution due to transportation of atmospheric CO2 by wind is associated with biomass burning in Sumatra, Indonesia. The GOSAT data and the Satellite measurements are able to measure the increase of the atmosphere CO2 values over different regions.

  5. Investigating different filter and rescaling methods on simulated GRACE-like TWS variations for hydrological applications

    Science.gov (United States)

    Zhang, Liangjing; Dobslaw, Henryk; Dahle, Christoph; Thomas, Maik; Neumayer, Karl-Hans; Flechtner, Frank

    2017-04-01

    By operating for more than one decade now, the GRACE satellite provides valuable information on the total water storage (TWS) for hydrological and hydro-meteorological applications. The increasing interest in use of the GRACE-based TWS requires an in-depth assessment of the reliability of the outputs and also its uncertainties. Through years of development, different post-processing methods have been suggested for TWS estimation. However, since GRACE offers an unique way to provide high spatial and temporal scale TWS, there is no global ground truth data available to fully validate the results. In this contribution, we re-assess a number of commonly used post-processing methods using a simulated GRACE-type gravity field time-series based on realistic orbits and instrument error assumptions as well as background error assumptions out of the updated ESA Earth System Model. Three non-isotropic filter methods from Kusche (2007) and a combined filter from DDK1 and DDK3 based on the ground tracks are tested. Rescaling factors estimated from five different hydrological models and the ensemble median are applied to the post-processed simulated GRACE-type TWS estimates to correct the bias and leakage. Time variant rescaling factors as monthly scaling factors and scaling factors for seasonal and long-term variations separately are investigated as well. Since TWS anomalies out of the post-processed simulation results can be readily compared to the time-variable Earth System Model initially used as "truth" during the forward simulation step, we are able to thoroughly check the plausibility of our error estimation assessment (Zhang et al., 2016) and will subsequently recommend a processing strategy that shall also be applied for planned GRACE and GRACE-FO Level-3 products for terrestrial applications provided by GFZ. Kusche, J., 2007:Approximate decorrelation and non-isotropic smoothing of time-variable GRACE-type gravity field models. J. Geodesy, 81 (11), 733-749, doi:10

  6. Investigation of variations and trends in solar radiation in Klang Valley Region, Malaysia

    International Nuclear Information System (INIS)

    Mohamed Elnour Yassen, Jamaluddin Mohd Jahi

    2006-01-01

    The objective of this study is to investigate variations and trends in the global solar radiation in Klang Valley region. The least square method was used for the trend analysis. Since the available time series covers 27 years, linear regression was preferred for the trend analysis. The linear trend is used mainly to test the change in solar radiation and to set limits on the rate of change. Trend line and values and significance levels of the slopes have been found. The seasonal and the annual average values were computed from the monthly average radiation data. The seasonal and annual average solar radiation values were designated as dependent variables, and thus, were fitted linearly for season and annual means for each station. The results showed that the mean of maximum incoming global radiation in Sepember with a value of 21.1 MJ m-2 at Petaling Jaya, while the mean minimum in November and December with values of 10.7 and 10.9 MJ m-2 at Petaling Jaya. The low amounts of solar radiation received in November and December are due to greater cloudiness during the period coinciding with the northeast monsoon season. On rainy days, very little global solar radiation received in November and December are due to greater cloudiness during the period coinciding with the northeast monsoon season. On rainy days, very little global solar radiation is received. The distribution of the seasonal mean values of solar radiation exhibits a high symmetry. Inter-monsoon seasons (April-May) and (October-November) show a similar behavior, just like the northeast monsoon season. The overall average rate of change in global solar radiation during 1975-2002 and 1977-2000 is represented by the slope of the linear regression was small (-0.126 and -0.314 MJ m-2 per year for Subang Airport and Petaling Jaya respectively)

  7. Experimental investigation on variation of physical properties of coal samples subjected to microwave irradiation

    Science.gov (United States)

    Hu, Guozhong; Yang, Nan; Xu, Guang; Xu, Jialin

    2018-03-01

    The gas drainage rate of low-permeability coal seam is generally less than satisfactory. This leads to the gas disaster of coal mine, and largely restricts the extraction of coalbed methane (CBM), and increases the emission of greenhouse gases in the mining area. Consequently, enhancing the gas drainage rate is an urgent challenge. To solve this problem, a new approach of using microwave irradiation (MWR) as a non-contact physical field excitation method to enhance gas drainage has been attempted. In order to evaluate the feasibility of this method, the methane adsorption, diffusion and penetrability of coal subjected to MWR were experimentally investigated. The variation of methane adsorbed amount, methane diffusion speed and absorption loop for the coal sample before and after MWR were obtained. The findings show that the MWR can change the adsorption property and reduce the methane adsorption capacity of coal. Moreover, the methane diffusion characteristic curves for both the irradiated coal samples and theoriginal coal samples present the same trend. The irradiated coal samples have better methane diffusion ability than the original ones. As the adsorbed methane decreases, the methane diffusion speed increases or remain the same for the sample subjected to MWR. Furthermore, compared to the original coal samples, the area of the absorption loop for irradiated samples increases, especially for the micro-pore and medium-pore stage. This leads to the increase of open pores in the coal, thus improving the gas penetrability of coal. This study provides supports for positive MWR effects on changing the methane adsorption and improving the methane diffusion and the gas penetrability properties of coal samples.

  8. A genome-wide investigation of copy number variation in patients with sporadic brain arteriovenous malformation.

    Directory of Open Access Journals (Sweden)

    Nasrine Bendjilali

    Full Text Available Brain arteriovenous malformations (BAVM are clusters of abnormal blood vessels, with shunting of blood from the arterial to venous circulation and a high risk of rupture and intracranial hemorrhage. Most BAVMs are sporadic, but also occur in patients with Hereditary Hemorrhagic Telangiectasia, a Mendelian disorder caused by mutations in genes in the transforming growth factor beta (TGFβ signaling pathway.To investigate whether copy number variations (CNVs contribute to risk of sporadic BAVM, we performed a genome-wide association study in 371 sporadic BAVM cases and 563 healthy controls, all Caucasian. Cases and controls were genotyped using the Affymetrix 6.0 array. CNVs were called using the PennCNV and Birdsuite algorithms and analyzed via segment-based and gene-based approaches. Common and rare CNVs were evaluated for association with BAVM.A CNV region on 1p36.13, containing the neuroblastoma breakpoint family, member 1 gene (NBPF1, was significantly enriched with duplications in BAVM cases compared to controls (P = 2.2×10(-9; NBPF1 was also significantly associated with BAVM in gene-based analysis using both PennCNV and Birdsuite. We experimentally validated the 1p36.13 duplication; however, the association did not replicate in an independent cohort of 184 sporadic BAVM cases and 182 controls (OR = 0.81, P = 0.8. Rare CNV analysis did not identify genes significantly associated with BAVM.We did not identify common CNVs associated with sporadic BAVM that replicated in an independent cohort. Replication in larger cohorts is required to elucidate the possible role of common or rare CNVs in BAVM pathogenesis.

  9. Variation in Direct Access to Tests to Investigate Cancer: A Survey of English General Practitioners.

    Directory of Open Access Journals (Sweden)

    Brian D Nicholson

    Full Text Available The 2015 NICE guidelines for suspected cancer recommend that English General Practitioners have direct access to diagnostic tests to investigate symptoms of cancer that do not meet the criteria for urgent referral. We aimed to identify the proportion of GPs in England with direct access to these tests.We recruited 533 English GPs through a national clinical research network to complete an online survey about direct access to laboratory, radiology, and endoscopy tests in the three months leading up to the release of the 2015 NICE guidance. If they had direct access to a diagnostic test, GPs were asked about the time necessary to arrange a test and receive a report. Results are reported by NHS sub-region and, adjusting for sampling, for England as a whole.Almost all GPs reported direct access to x-ray and laboratory investigations except faecal occult blood testing (54%, 95% CI 49-59% and urine protein electrophoresis (89%, 95% CI 84-92%. Fewer GPs had direct access to CT scans (54%, 95% CI 49-59% or endoscopy (colonoscopy 32%, 95% CI 28-37%; gastroscopy 72%, 95% CI 67-77%. There was significant variation in direct access between NHS regions for the majority of imaging tests-for example, from 20 to 85% to MRI. Apart from x-ray, very few GPs (1-22% could access radiology and endoscopy within the timescales recommended by NICE. The modal request to test time was 2-4 weeks for routine radiology and 4-6 weeks for routine endoscopy with results taking another 1-2 weeks.At the time that the 2015 NICE guideline was released, local investment was required to not only provide direct access but also reduce the interval between request and test and speed up reporting. Further research using our data as a benchmark is now required to identify whether local improvements in direct access have been achieved in response to the NICE targets. If alternative approaches to test access are to be proposed they must be piloted comprehensively and underpinned by robust

  10. Variation in Direct Access to Tests to Investigate Cancer: A Survey of English General Practitioners

    Science.gov (United States)

    Nicholson, Brian D.; Oke, Jason L.; Rose, Peter W.; Mant, David

    2016-01-01

    Background The 2015 NICE guidelines for suspected cancer recommend that English General Practitioners have direct access to diagnostic tests to investigate symptoms of cancer that do not meet the criteria for urgent referral. We aimed to identify the proportion of GPs in England with direct access to these tests. Methods We recruited 533 English GPs through a national clinical research network to complete an online survey about direct access to laboratory, radiology, and endoscopy tests in the three months leading up to the release of the 2015 NICE guidance. If they had direct access to a diagnostic test, GPs were asked about the time necessary to arrange a test and receive a report. Results are reported by NHS sub-region and, adjusting for sampling, for England as a whole. Results Almost all GPs reported direct access to x-ray and laboratory investigations except faecal occult blood testing (54%, 95% CI 49–59%) and urine protein electrophoresis (89%, 95% CI 84–92%). Fewer GPs had direct access to CT scans (54%, 95% CI 49–59%) or endoscopy (colonoscopy 32%, 95% CI 28–37%; gastroscopy 72%, 95% CI 67–77%). There was significant variation in direct access between NHS regions for the majority of imaging tests—for example, from 20 to 85% to MRI. Apart from x-ray, very few GPs (1–22%) could access radiology and endoscopy within the timescales recommended by NICE. The modal request to test time was 2–4 weeks for routine radiology and 4–6 weeks for routine endoscopy with results taking another 1–2 weeks. Conclusion At the time that the 2015 NICE guideline was released, local investment was required to not only provide direct access but also reduce the interval between request and test and speed up reporting. Further research using our data as a benchmark is now required to identify whether local improvements in direct access have been achieved in response to the NICE targets. If alternative approaches to test access are to be proposed they must be

  11. Inter- and intraspecific genetic variation in Hippophae (Elaeagnaceae) investigated by RAPD markers

    Czech Academy of Sciences Publication Activity Database

    Bartish, Igor; Jeppsson, N.; Bartish, G.; Lu, R.; Nybom, H.

    2000-01-01

    Roč. 225, - (2000), s. 85-101 ISSN 0378-2697 Institutional research plan: CEZ:AV0Z6005908 Keywords : Elaeagnaceae * sea buckthorn * genetic variation Subject RIV: EF - Botanics Impact factor: 1.408, year: 2000

  12. Emotional voice processing: investigating the role of genetic variation in the serotonin transporter across development.

    Directory of Open Access Journals (Sweden)

    Tobias Grossmann

    Full Text Available The ability to effectively respond to emotional information carried in the human voice plays a pivotal role for social interactions. We examined how genetic factors, especially the serotonin transporter genetic variation (5-HTTLPR, affect the neurodynamics of emotional voice processing in infants and adults by measuring event-related brain potentials (ERPs. The results revealed that infants distinguish between emotions during an early perceptual processing stage, whereas adults recognize and evaluate the meaning of emotions during later semantic processing stages. While infants do discriminate between emotions, only in adults was genetic variation associated with neurophysiological differences in how positive and negative emotions are processed in the brain. This suggests that genetic association with neurocognitive functions emerges during development, emphasizing the role that variation in serotonin plays in the maturation of brain systems involved in emotion recognition.

  13. Investigating the variations in survival rates for very preterm infants in ten European regions: the MOSAIC birth cohort

    DEFF Research Database (Denmark)

    Draper, Elizabeth S; Zeitlin, Jennifer; Fenton, Alan C

    2008-01-01

    OBJECTIVE: To investigate the variation in the survival rate and the mortality rates for very preterm infants across Europe. DESIGN: A prospective birth cohort of very preterm infants for ten geographically defined European regions during 2003 followed to discharge home from hospital. PARTICIPANTS...... for NIC. For babies order...

  14. Variation in human mate choice: Simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating

    NARCIS (Netherlands)

    Zietsch, B.P.; Verweij, K.J.H.; Heath, A.C.; Martin, N.G.

    2011-01-01

    Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents (N > 20,000 individuals) to test for genetic and family

  15. Investigating elusive stylistic variation in a tight-knit language community

    NARCIS (Netherlands)

    Knooihuizen, Remco; Svabo Hansen, Zakaris; Johansen, Anfinnur; Petersen, Hjalmar P.; Reinert, Lena

    2017-01-01

    Ever since Labov's pioneering work in New York City in the 1960s (e.g., Labov, 1972), initial sociolinguistic surveys of language communities have taken into account the same social factors as predictors of linguistic variation: age, sex (or gender), social class, and speech style. This set-up works

  16. Investigation of microbial adaptation to salinity variation for treatment of reverse osmosis concentrate by membrane bioreactor

    DEFF Research Database (Denmark)

    Jang, Duksoo; Moon, Chungman; Ahn, Kyuhong

    2014-01-01

    Even though reverse osmosis (RO) technologies are widely used for sustainable water reclamation, the control of concentrates containing a high concentration of dissolved matters originated from feed water should be considered. The effect of variations in salinity on biological wastewater treatment...

  17. Investigation of Spatial Variation of Sea States Offshore of Humboldt Bay CA Using a Hindcast Model.

    Energy Technology Data Exchange (ETDEWEB)

    Dallman, Ann Renee; Neary, Vincent Sinclair

    2014-10-01

    Spatial variability of sea states is an important consideration when performing wave resource assessments and wave resource characterization studies for wave energy converter (WEC) test sites and commercial WEC deployments. This report examines the spatial variation of sea states offshore of Humboldt Bay, CA, using the wave model SWAN . The effect of depth and shoaling on bulk wave parameters is well resolved using the model SWAN with a 200 m grid. At this site, the degree of spatial variation of these bulk wave parameters, with shoaling generally perpendicular to the depth contours, is found to depend on the season. The variation in wave height , for example, was higher in the summer due to the wind and wave sheltering from the protruding land on the coastline north of the model domain. Ho wever, the spatial variation within an area of a potential Tier 1 WEC test site at 45 m depth and 1 square nautical mile is almost negligible; at most about 0.1 m in both winter and summer. The six wave characterization parameters recommended by the IEC 6 2600 - 101 TS were compared at several points along a line perpendicular to shore from the WEC test site . As expected, these parameters varied based on depth , but showed very similar seasonal trends.

  18. INVESTIGATION OF b-VALUE VARIATIONS IN THE AFRICAN AND PARTS OF EURASIAN PLATES

    Directory of Open Access Journals (Sweden)

    Awoyemi, M. O.

    2017-06-01

    Full Text Available Numerous earthquakes have occurred along the collision zones of the African and parts of Eurasian plates. Some of these earthquakes along these zones have generated tsunamis. To mitigate this hazard, knowledge of b-values of the Gutenberg – Richter relation for tectonic earthquakes in the African and parts of Eurasian plates is essential. The temporal variations of b-values were evaluated using sliding time windows with each window containing a total of 100 events with a view to utilizing the results as a precursor for the earthquake occurrence. The spatial variation of b-values of the study area was also delineated by dividing it into grids and calculating the b-values for each grid using constant radius and constant number of events. Results obtained from the temporal variation of b-values showed that earthquakes of large magnitudes occurred when the b-values were low while earthquakes of small magnitudes occurred when the b-values were high throughout the study period. The results of the spatial distribution of b-values also showed that earthquakes of large magnitudes occurred in areas of low b-values while earthquakes of small magnitudes occurred in areas of high b-values. The study therefore concluded that the temporal and spatial variations of b-values might be considered as a precursor for earthquake prediction.

  19. An investigation into the relationship between thickness variations and manufacturing techniques of mouthguards.

    Science.gov (United States)

    Farrington, Timothy; Coward, Trevor; Onambele-Pearson, Gladys; Taylor, Rebecca L; Earl, Philip; Winwood, Keith

    2016-02-01

    The aim of this study was to measure the finished thickness of a single identical 4-mm EVA mouthguard model from a large fabricated sample group and to evaluate the degree of material thinning and variations during the fabrication process. Twenty boxes were distributed to dental technician participants, each containing five duplicated dental models (n = 100), alongside 5 × 4 mm mouthguard blanks and a questionnaire. The mouthguards were measured using electronic callipers (resolution: ±0.01 mm) at three specific points. The five thickest and thinnest mouthguards were examined using a CT scanner to describe the surface typography unique to each mouthguard, highlighting dimensional thinning patterns during the fabrication process. Of the three measurement points, the anterior sulcus point of the mouthguard showed a significant degree of variation (up to 34% coefficient of variation), in finished mouthguard thickness between individuals. The mean thickness of the mouthguards in the anterior region was 1.62 ± 0.38 mm with a range of 0.77-2.80 mm. This variation was also evident in the occlusion and posterior lingual regions but to a lesser extent (up to 12.2% and 9.8% variations, respectively). This study highlights variability in the finished thickness of the mouthguards especially in the anterior sulcus region measurement point, both within and between individuals. At the anterior region measurement point of the mouthguard, the mean thickness was 1.62 mm, equating to an overall material thinning of 59.5% when using a single 4-mm EVA blank. This degree of thinning is comparative to previous single operator research studies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Procedural success and intra-hospital outcome related to left atrial appendage morphology in patients that receive an interventional left atrial appendage closure.

    Science.gov (United States)

    Fastner, Christian; Behnes, Michael; Sartorius, Benjamin; Wenke, Annika; El-Battrawy, Ibrahim; Ansari, Uzair; Gill, Ishar-Singh; Borggrefe, Martin; Akin, Ibrahim

    2017-08-01

    The interventional left atrial appendage (LAA) closure represents an emerging alternative to oral anticoagulation for stroke prevention in certain atrial fibrillation patients. Preliminary results have suggested high procedural success rates and fewer peri-interventional complications; however, there persists an insufficient understanding of the role of many underlying confounding variables (e.g., anatomical characteristics). It was investigated whether varying LAA morphologies influence procedural success as well as in-hospital outcome. Sixty-seven patients ineligible for long-term oral anticoagulation were included in this single-center, prospective, observational registry spanning from the years 2014 to 2016. Interventions were performed with the Watchman occluder (Boston Scientific, Natick, MA) or the Amplatzer Amulet (St. Jude Medical, St. Paul, MN), at the operator's discretion. Results derived from the data describing procedural success, fluoroscopy, and peri-interventional safety events were classified according to the presenting LAA morphology (cauliflower, cactus, windsock, and chicken wing). Rates of successful implantation were high across all groups (≥98%; P = 0.326). Surrogate parameters underlining procedural complexity like median total duration (P = 0.415), median fluoroscopy time (P = 0.459), median dose area product (P = 0.698), and the median amount of contrast agent (P = 0.076) demonstrated similar results across all groups. Likewise, the periprocedural complication rate was not significantly different and was mainly restricted to minor bleeding events. Irrespective of the varying morphological presentation of the LAA, the procedural success rates, interventional characteristics, and safety events did not significantly differ among patients receiving an interventional LAA closure. © 2017 Wiley Periodicals, Inc.

  1. Investigating the variations in survival rates for very preterm infants in ten European regions: the MOSAIC birth cohort

    DEFF Research Database (Denmark)

    Draper, Elizabeth S; Zeitlin, Jennifer; Fenton, Alan C

    2008-01-01

    OBJECTIVE: To investigate the variation in the survival rate and the mortality rates for very preterm infants across Europe. DESIGN: A prospective birth cohort of very preterm infants for ten geographically defined European regions during 2003 followed to discharge home from hospital. PARTICIPANTS...... of the infants from 24 to 27 weeks gestation survived to discharge home from NIC. However large variations were seen in the timing of the deaths by region. Among all fetuses alive at onset of labour of 24-27 weeks gestation, between 84.0% and 98.9% were born alive and between 64.6% and 97.8% were admitted...

  2. Investigating the variations in survival rates for very preterm infants in ten European regions: the MOSAIC birth cohort

    DEFF Research Database (Denmark)

    Draper, Elizabeth S; Zeitlin, Jennifer; Fenton, Alan C

    2008-01-01

    OBJECTIVE: To investigate the variation in the survival rate and the mortality rates for very preterm infants across Europe. DESIGN: A prospective birth cohort of very preterm infants for ten geographically defined European regions during 2003 followed to discharge home from hospital. PARTICIPANTS...... for NIC. For babies babies alive at onset of labour were admitted to neonatal intensive care. CONCLUSIONS: There are wide variations in the survival rates to discharge from NIC for very preterm deliveries and in the timing of death across the MOSAIC regions. In order...

  3. Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: variation in sensitivity among species.

    Science.gov (United States)

    Snodgrass, Joel W; Casey, Ryan E; Joseph, Debra; Simon, Judith A

    2008-07-01

    Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds.

  4. Origins of Tropospheric Ozone Interannual Variation (IAV) over Reunion: A Model Investigation

    Science.gov (United States)

    Liu, Junhua; Rodriguez, Jose M.; Thompson, Anne M.; Logan, Jennifer A.; Douglass, Anne R.; Olsen, Mark A.; Steenrod, Stephen D.; Posny, Francoise

    2016-01-01

    Observations from long-term ozonesonde measurements show robust variations and trends in the evolution of ozone in the middle and upper troposphere over Reunion Island (21.1 degrees South Latitude, 55.5 degrees East Longitude) in June-August. Here we examine possible causes of the observed ozone variation at Reunion Island using hindcast simulations by the stratosphere-troposphere Global Modeling Initiative chemical transport model for 1992-2014, driven by assimilated Modern-Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields. Reunion Island is at the edge of the subtropical jet, a region of strong stratospheric-tropospheric exchange. Our analysis implies that the large interannual variation (IAV) of upper tropospheric ozone over Reunion is driven by the large IAV of the stratospheric influence. The IAV of the large-scale, quasi-horizontal wind patterns also contributes to the IAV of ozone in the upper troposphere. Comparison to a simulation with constant emissions indicates that increasing emissions do not lead to the maximum trend in the middle and upper troposphere over Reunion during austral winter implied by the sonde data. The effects of increasing emission over southern Africa are limited tothe lower troposphere near the surface in August-September.

  5. An investigation on inter-individual variation in perceived discomfort of static posture holding.

    Science.gov (United States)

    Ogutu, Jack; Park, Woojin; Son, Minseok

    2015-01-01

    Realizing population-level discomfort evaluation and control of common static posture holding tasks requires an understanding of the inter-individual variation in discomfort perception. However, little research is available. This study aimed to determine the types of mathematical probability distribution suitable for modeling population discomfort distributions of various static posture holding tasks and characterize how the magnitude of inter-individual variation in perceived discomfort varies across static posture holding tasks. Ten male and ten female subjects participated. The participants conducted static posture holding for a set of 180 short-duration (20-second-long) static posture holding tasks and subjectively rated the overall perceived discomfort for each task using the Borg CR-10 discomfort scale. Statistical analyses were conducted according to the study objectives. The static posture holding tasks exhibited multifarious discomfort distribution patterns. Probability distribution identification analyses indicated that no single distribution type could represent population discomfort distributions universally across different static posture holding tasks. Sample standard deviation of discomfort ratings data quantifying the magnitude of inter-individual variation in discomfort perception varied considerably across static posture holding tasks. It seemed to have a positive relationship with sample mean within the range of the experimental conditions. Population-level evaluation of discomforts associated with static posture holding tasks must be based on careful examinations of empirical discomfort distributions.

  6. The use of high-throughput DNA sequencing in the investigation of antigenic variation: application to Neisseria species.

    Directory of Open Access Journals (Sweden)

    John K Davies

    Full Text Available Antigenic variation occurs in a broad range of species. This process resembles gene conversion in that variant DNA is unidirectionally transferred from partial gene copies (or silent loci into an expression locus. Previous studies of antigenic variation have involved the amplification and sequencing of individual genes from hundreds of colonies. Using the pilE gene from Neisseria gonorrhoeae we have demonstrated that it is possible to use PCR amplification, followed by high-throughput DNA sequencing and a novel assembly process, to detect individual antigenic variation events. The ability to detect these events was much greater than has previously been possible. In N. gonorrhoeae most silent loci contain multiple partial gene copies. Here we show that there is a bias towards using the copy at the 3' end of the silent loci (copy 1 as the donor sequence. The pilE gene of N. gonorrhoeae and some strains of Neisseria meningitidis encode class I pilin, but strains of N. meningitidis from clonal complexes 8 and 11 encode a class II pilin. We have confirmed that the class II pili of meningococcal strain FAM18 (clonal complex 11 are non-variable, and this is also true for the class II pili of strain NMB from clonal complex 8. In addition when a gene encoding class I pilin was moved into the meningococcal strain NMB background there was no evidence of antigenic variation. Finally we investigated several members of the opa gene family of N. gonorrhoeae, where it has been suggested that limited variation occurs. Variation was detected in the opaK gene that is located close to pilE, but not at the opaJ gene located elsewhere on the genome. The approach described here promises to dramatically improve studies of the extent and nature of antigenic variation systems in a variety of species.

  7. Precise measurement of seismic traveltimes - Investigation of variation from tidal stress in shallow crust

    Science.gov (United States)

    Liu, Hsi-Ping; Westerlund, Robert E.; Fletcher, Jon B.

    1983-05-01

    We have conducted 8 precise seismic surveys near Hollister, CA, over a period of 1 y in an attempt to detect the traveltime variation caused by the solid-earth tidal stress. The surveys were conducted along a 600 m baseline located in quartz monzonite hills 2 km west of the San Andreas fault. A 656 cm³ air gun fired in a mud-filled pit 2 m deep provided a repeatable seismic source. The signals from two 2.3 Hz vertical-component geophones 600 m apart were digitized at a nominal rate of 600 samples/s by two cassette recorders modified for precise synchronization of data sampling against a master clock. Each survey consists of ˜ 100 traveltime measurements over the 12 h period between 6 p.m. and 6 a.m. local time; the time frame of each experiment was limited by daytime cultural noises. Analysis of traveltime variation is done either by timing of amplitude extrema or by cross-correlation of a waveform constructed from the digital data by a cubic-spline interpolation. Fractional error of the repeatability of traveltime measurement is typically ±3.3 × 10-4 for the first high-frequency, large amplitude arrival following the direct body waves. The first survey, conducted at a spring tide in August, 1981, showed a variation of Δt/t ˜ 2 × 10-3 and correlated in time with the extensional tidal strain component along the baseline direction. The next two surveys, conducted at two neap tides, showed variation of Δt/t ˜ 6 × 10-4 and also correlated with the same tidal strain component. However, the other 5 surveys conducted after the onset of 1981 rainy season and into the 1982 dry season, 4 at spring tides and 1 between a spring and a neap tide, showed traveltime constant to within 1 standard deviation. These results corroborate only partially the previously reported tidal stress variation of traveltimes in the shallow crust.

  8. Using SEBAL to Investigate How Variations in Climate Impact on Crop Evapotranspiration

    Directory of Open Access Journals (Sweden)

    Giorgos Papadavid

    2017-07-01

    Full Text Available Water allocation to crops, and especially to the most water intensive ones, has always been of great importance in agricultural processes. Deficit or excessive irrigation could create either crop health-related problems or water over-consumption, respectively. The latter could lead to groundwater depletion and deterioration of its quality through deep percolation of agrichemical residuals. In this context, and under the current conditions where Cyprus is facing effects of possible climate changes, the purpose of this study seeks to estimate the needed crop water requirements of the past (1995–2004 and the corresponding ones of the present (2005–2015 in order to test if there were any significant changes regarding the crop water requirements of the most water-intensive trees in Cyprus. The Mediterranean region has been identified as the region that will suffer the most from variations of climate. Thus the paper refers to effects of these variations on crop evapotranspiration (ETc using remotely-sensed data from Landsat TM/ETM+/OLI employing a sound methodology used worldwide, the Surface Energy Balance Algorithm for Land (SEBAL. Though the general feeling is that of changes on climate will consequently affect ETc, our results indicate that there is no significant effect of climate variation on crop evapotranspiration, despite the fact that some climatic factors have changed. Applying Student’s t-test, the mean values for the most water-intensive trees in Cyprus of the 1994–2004 decade have shown no statistical difference from the mean values of 2005–2015 for all the cases, concluding that the climate change taking place in the past decades in Cyprus have either not affected the crop evapotranspiration or the crops have managed to adapt to the new environmental conditions through time.

  9. Transporte intra-hospitalar de pacientes internados em UTI Neonatal: fatores de risco para intercorrências Intra-hospital transport of neonatal intensive care patients: risk factors for complications

    Directory of Open Access Journals (Sweden)

    Anna Luiza P. Vieira

    2007-09-01

    Full Text Available OBJETIVO: Estudar os fatores associados à hipotermia e ao aumento da necessidade de oxigênio e/ou suporte ventilatório durante o transporte intra-hospitalar de pacientes internados em Unidade de Terapia Intensiva neonatal. MÉTODOS: Estudo prospectivo de todos os pacientes internados na unidade neonatal que necessitaram de transporte intra-hospitalar de janeiro de 1997 a dezembro de 2000, entre segundas-feiras e sextas-feiras, das 8h às 17h. Fatores associados à hipotermia e ao aumento da necessidade de oxigênio e/ou de suporte ventilatório durante e até duas horas após o transporte foram estudados por meio de regressão logística. RESULTADOS: Foram realizados 502 transportes no período. Os pacientes tinham em média 2.000g, 35 semanas de idade gestacional ao nascer e 22 dias de vida. As principais indicações do transporte foram: cirurgia e realização de exames de imagem. A hipotermia ocorreu em 17% dos transportes e o aumento da necessidade de oxigênio e/ou de suporte ventilatório em 7%. Fatores associados à hipotermia foram: duração do transporte >3h (OR=2,1; IC95%=1,2-3,6, presença de malformações neurológicas (OR=1,7; IC95%=1,1-2,5, transporte realizado em 1997 (OR=1,7; IC95%=1,1-2,6 e peso no transporte >3.500g (OR=0,3; IC95%=0,16-0,68. Fatores de risco para o aumento da necessidade de oxigênio e/ou de suporte ventilatório foram: idade gestacional ao nascimento em semanas (OR=0,9; IC95%=0,8-0,9, idade em dias no transporte (OR=1,0; IC95%=1,0-1,1 e presença de malformações gastrintestinais e geniturinárias (OR=3,1; IC95%=1,6-6,2. CONCLUSÕES: As intercorrências relativas ao transporte intra-hospitalar são freqüentes nos neonatos em UTI e estão associadas às condições dos pacientes e dos transportes.OBJECTIVE: Evaluate factors associated with hypothermia and increased need of oxygen and/or ventilatory support during intra-hospital transport of neonatal intensive care patients. METHODS: Prospective study of

  10. Diurnal variation of tension-type headache intensity and exacerbation: An investigation using computerized ecological momentary assessment

    Directory of Open Access Journals (Sweden)

    Kikuchi Hiroe

    2012-09-01

    Full Text Available Abstract Backgrounds Tension-type headache is a common psychosomatic disease. However, diurnal variation of headache is yet to be clarified, perhaps due to the lack of an appropriate method to investigate it. Like other painful diseases, it would be helpful to know if there is diurnal variation in tension-type headaches, both for managing headaches and understanding their pathophysiology. The aim of this study was to determine if there is diurnal variation in the intensity and exacerbation of tension-type headache. Methods Patients (N = 31 with tension-type headache recorded for one week their momentary headache intensity several times a day and their acute headache exacerbations using a watch-type computer as an electronic diary (computerized ecological momentary assessment. Multilevel modeling was used to test the effects of time of day on momentary headache intensity and on the occurrence of acute exacerbations. Results A significant diurnal variation in momentary headache intensity was shown (P = 0.0005, with the weakest headaches in the morning and a peak in the late afternoon. A between-individual difference in the diurnal pattern was suggested. On-demand medication use was associated with a different diurnal pattern (P = 0.025, suggesting that headache intensity decreases earlier in the evening in subjects who used on-demand medication, while headache subtype, prophylactic medication use, and sex were not associated with the difference. The occurrence of acute headache exacerbation also showed a significant diurnal variation, with a peak after noon (P = 0.0015. Conclusions Tension-type headache was shown to have a significant diurnal variation. The relation to pathophysiology and psychosocial aspects needs to be further explored.

  11. Microstructural investigation of variations in the proof strength of Nimonic PE16

    International Nuclear Information System (INIS)

    Riley, B.F.; Wilson, E.G.; Jones, A.R.

    1987-01-01

    Nimonic PE16 shows a correlation of stress rupture behaviour after irradiation with proof strength. Proof testing of material from bars from several casts yielded a relationship (Hall-Petch) between the peak-aged proof stress and grain size -1/2 but the scatter in proof stress values at a given grain size merited further microstructural study. Transmission electron microscopy revealed that high proof stress material contained dislocation densities consistent with material which had received 1 to 2% cold work, verified by examination of lightly prestrained tensile specimens. Ageing to peak strength induced partial recovery but some variability in proof stress remained. Variations in γ' size and composition having been eliminated, the scatter in proof stress values was attributed to variable cold work induced by the commercial bar straightening process. (Author)

  12. Themes and variations: An exploratory international investigation into resuscitation decision-making.

    Science.gov (United States)

    Gibbs, Alexander J O; Malyon, Alexandra C; Fritz, Zoë B McC

    2016-06-01

    Do Not Attempt Cardiopulmonary Resuscitation (DNACPR) decisions are made in hospitals throughout the globe. International variation in clinicians' perception of DNACPR decision-making and implementation and the factors influencing such variation has not previously been explored. A questionnaire asking how DNACPR decisions are made, communicated and perceived in their country was composed: it consisted of seven closed-answer and four open-answer questions. It was distributed to 143 medical professionals with prior published material relating to DNACPR decisions. Under-represented geographical areas were identified and an additional 34 physicians were contacted through medical colleagues and students at the university hospital from which this study was based. The respondents had 4 weeks to answer the questionnaire. 78 responses (44%) were received from 43 countries. All continents were represented. 88% of respondents reported a method for implementing DNACPR decisions, 90% of which discussed resuscitation wishes with the patient at least half of the time. 94% of respondents thought that national guidance for DNACPR order implementation should exist; 53% of countries surveyed reported existence of such guidance. Cultural attitudes towards death, medical education and culture, health economics and the societal role of family were commonly identified as factors influencing perception of DNACPR decisions. The majority of countries surveyed make some form of DNACPR decision but differing cultures and economic status contribute towards a heterogeneity of approaches to resuscitation decision-making. Adequacy of relevant medical education and national policy are two areas that were regularly identified as impacting upon the processes of DNACPR decision-making and implementation. Copyright © 2016. Published by Elsevier Ireland Ltd.

  13. Extensive lava flow fields on Venus: Preliminary investigation of source elevation and regional slope variations

    Science.gov (United States)

    Magee-Roberts, K.; Head, James W., III; Lancaster, M. G.

    1992-01-01

    Large-volume lava flow fields have been identified on Venus, the most areally extensive of which are known as fluctus and have been subdivided into six morphologic types. Sheetlike flow fields (Type 1) lack the numerous, closely spaced, discrete lava flow lobes that characterize digitate flow fields. Transitional flow fields (Type 2) are similar to sheetlike flow fields but contain one or more broad flow lobes. Digitate flow fields are divided further into divergent (Types 3-5) and subparallel (Type 6) classes on the basis of variations in the amount of downstream flow divergence. As a result of our previous analysis of the detailed morphology, stratigraphy, and tectonic associations of Mylitta Fluctus, we have formulated a number of questions to apply to all large flow fields on Venus. In particular, we would like to address the following: (1) eruption conditions and style of flow emplacement (effusion rate, eruption duration), (2) the nature of magma storage zones (presence of neutral buoyancy zones, deep or shallow crustal magma chambers), (3) the origin of melt and possible link to mantle plumes, and (4) the importance of large flow fields in plains evolution. To answer these questions we have begun to examine variations in flow field dimension and morphology; the distribution of large flow fields in terms of elevation above the mean planetary radius; links to regional tectonic or volcanic structures (e.g., associations with large shield edifices, coronae, or rift zones); statigraphic relationships between large flow fields, volcanic plains, shields, and coronae; and various models of flow emplacement in order to estimate eruption parameters. In this particular study, we have examined the proximal elevations and topographic slopes of 16 of the most distinctive flow fields that represent each of the 6 morphologic types.

  14. Investigation of Time Effect on Resistivity Variation of 10 MeV Electron Beam Irradiated LDPE and HDPE

    International Nuclear Information System (INIS)

    Ziaie, F.

    2006-01-01

    Charges occur in both the physical and/or chemical nature and concentration of defects in the crystalline region, and traps at chain fold-amorphous interfaces. In this work attempt has bean made to investigate the time effect on the variation of surface and volume resistivity of the LDPE and HDPE samples were irradiated under the 10 MeV electron beam of Rhodotron accelerator. In fact, the aim was to investigate these variations during about one mount after irradiation which is changing due to the charge storage in the polyethylene. The samples were prepared in sheet form with the thickness of 0.6±0.1 mm and irradiated at the dose range of 70 to 370 kGy. All the samples were kept at room temperature in laboratory. The results show an increment at about 25 days after irradiation in surface resistivity and decreasing later on for all the samples. The results of volume resistivity measurements didn't show any significant variation

  15. Structural variations in lignite coal: a small angle X-ray scattering investigation

    Science.gov (United States)

    Sastry, P. U.; Sen, D.; Mazumder, S.; Chandrasekaran, K. S.

    2000-04-01

    The structural morphology of raw and processed lignite coal specimens from Neyveli (Tamil Nadu, India) is characterized over a length scale of 5-100 nm by small angle X-ray scattering (SAXS). The scattering profile from the unprocessed lignite specimen exhibits two distinct power laws indicating different fractal morphologies over different length scales: a pore fractal (dimension Dp˜2.7) for the pore-coal interface below 17 nm and a surface fractal (dimension Ds˜2.3) above 17 nm. As a result of industrial processing at different temperature, pressure and carbonization, significant changes in the structure are noticed as indicated by the scattering profiles. The fractal roughness of the pore-coal interface becomes smooth (average Ds˜2) for a large window of the length scale, whereas a part of the pore fractal transforms to a surface ( Ds˜2.8). The specimen treated at relatively higher temperature exhibits further variation from the fractal geometry with a tendency to form a new non-fractal micropore structure for the length scale ≤8 nm.

  16. Investigations on diurnal and seasonal variations of Schumann resonance oscillations in the auroral region

    Science.gov (United States)

    Rossi, C.; Palangio, P.

    2003-04-01

    Within the framework of the ITALIANTARTIDE project, continuous geomagnetic measurements were performed in the frequency range 5-20 Hz during 1996-97 at high latitude location (Baia Terra Nova Base, Antarctica; geomagnetic latitude 80.0° S, 307.7° E). BTN is a particularly important observation site, which is located in auroral region of known high electromagnetic activity in the ELF band. This site is connected by lines of force that reach the magnetopause in the daylight side at the Earth and the plasmasheet of the magnetotail in the nightside therefore BTN is able to look extreme regions of the magnetosphere. Its remote location Antarctica provides the important advantage that electromagnetic background noise is not corrupted by anthropogenic noise and there is a very low lightning activity. Schumann resonance oscillations are the most remarkable natural electromagnetic phenomena in the lower frequency side of ELF range. The measurements are concenned primarily with the properties of the components of the geomagnetic activity in the Schumann resonance frequency range, which forms a stable background signal level. We present the results on the long-term seasonal and diurnal variation of the background noise and its statistics in the frequency band from 5 to 20 Hz.

  17. A Genre-Based Investigation of Discussion Sections of Research Articles in Dentistry and Disciplinary Variation

    Science.gov (United States)

    Basturkmen, Helen

    2012-01-01

    Outwardly the rhetorical organisation of sections of research reports in different disciplines can appear similar. Close examination, however, may reveal subtle differences. Numerous studies have drawn on the genre-based approach developed by Swales (1990, 2004) to investigate the schematic structure of sections of articles in a range of…

  18. A Qualitative Investigation of Panelists' Experiences of Standard Setting Using Two Variations of the Bookmark Method

    Science.gov (United States)

    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…

  19. Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse

    Science.gov (United States)

    Reinisch, B. W.; Dandenault, P. B.; Galkin, I. A.; Hamel, R.; Richards, P. G.

    2018-02-01

    This paper presents a comparison of modeled and measured electron densities for the 21 August 2017 solar eclipse across the USA. The location of the instrument was (43.81°N, 247.32°E) where the maximum obscuration of 99.6% occurred at 17.53 hr UT on 21 August. The solar apparent time was 9.96 hr, and the duration of the eclipse was 2.7 hr. It was found that if it is assumed that there are no chromosphere emissions at totality, 30% coronal emission remaining at totality gave the best fit to the electron density variation at 150 km. The 30% coronal emission estimate has uncertainties associated with respect to uncertainties in the solar spectrum, the measured electron density, and the amount of chromosphere emissions remaining at totality. The agreement between the modeled and measured electron densities is excellent at 150 km with the assumed 30% coronal emission at totality. At other altitudes, the agreement is very good, but the altitude profile would be improved if the model peak electron density (NmF2) decayed more slowly to better match the data. The minimum NmF2 in the model occurs 10 min after totality when it decreases to 0.55 from its noneclipse value. The minimum of the NmF2 data occurs between 6 and 10 min after totality but is 15% larger. The total electron content decreases to 0.65 of its preeclipse value. These relative changes agree well with those predicted by others prior to the eclipse.

  20. Significance of operator variation and the angle of illumination in lineament analysis on synoptic images. [LANDSAT geological investigations

    Science.gov (United States)

    Siegal, B. S.; Short, N. M.

    1977-01-01

    The significance of operator variation and the angle of illumination in acquired imagery is analyzed for lineament analysis. Five operators analyzed a LANDSAT image and four photographs of a plastic relief map illuminated at a low angle from varying directions of the Prescott, Arizona region. Significant differences were found in both number and length of the lineaments recognized by the different investigators for the images. The actual coincidence of lineaments recognized by the investigators for the same image is exceptionally low. Even the directional data on lineament orientation is significantly different from operator to operator and from image to image. Cluster analysis of the orientation data displays a clustering by operators rather than by images. It is recommended that extreme caution be taken before attempting to compare different investigators' results in lineament analysis.

  1. Investigation of the effect of ionizing radiation on gene expression variation by the 'DNA chips': feasibility of a biological dosimeter

    International Nuclear Information System (INIS)

    Gruel, G.

    2005-01-01

    After having described the different biological effects of ionizing radiation and the different approaches to biological dosimetry, and introduced 'DNA chips' or DNA micro-arrays, the author reports the characterization of gene expression variations in the response of cells to a gamma irradiation. Both main aspects of the use DNA chips are investigated: fundamental research and diagnosis. This research thesis thus proposes an analysis of the effect of ionizing radiation using DNA chips, notably by comparing gene expression modifications measured in mouse irradiated lung, heart and kidney. It reports a feasibility study of bio-dosimeter based on expression profiles

  2. Investigating the effects of climate variations on bacillary dysentery incidence in northeast China using ridge regression and hierarchical cluster analysis

    Directory of Open Access Journals (Sweden)

    Guo Junqiao

    2008-09-01

    Full Text Available Abstract Background The effects of climate variations on bacillary dysentery incidence have gained more recent concern. However, the multi-collinearity among meteorological factors affects the accuracy of correlation with bacillary dysentery incidence. Methods As a remedy, a modified method to combine ridge regression and hierarchical cluster analysis was proposed for investigating the effects of climate variations on bacillary dysentery incidence in northeast China. Results All weather indicators, temperatures, precipitation, evaporation and relative humidity have shown positive correlation with the monthly incidence of bacillary dysentery, while air pressure had a negative correlation with the incidence. Ridge regression and hierarchical cluster analysis showed that during 1987–1996, relative humidity, temperatures and air pressure affected the transmission of the bacillary dysentery. During this period, all meteorological factors were divided into three categories. Relative humidity and precipitation belonged to one class, temperature indexes and evaporation belonged to another class, and air pressure was the third class. Conclusion Meteorological factors have affected the transmission of bacillary dysentery in northeast China. Bacillary dysentery prevention and control would benefit from by giving more consideration to local climate variations.

  3. Investigating the effects of climate variations on bacillary dysentery incidence in northeast China using ridge regression and hierarchical cluster analysis.

    Science.gov (United States)

    Huang, Desheng; Guan, Peng; Guo, Junqiao; Wang, Ping; Zhou, Baosen

    2008-09-25

    The effects of climate variations on bacillary dysentery incidence have gained more recent concern. However, the multi-collinearity among meteorological factors affects the accuracy of correlation with bacillary dysentery incidence. As a remedy, a modified method to combine ridge regression and hierarchical cluster analysis was proposed for investigating the effects of climate variations on bacillary dysentery incidence in northeast China. All weather indicators, temperatures, precipitation, evaporation and relative humidity have shown positive correlation with the monthly incidence of bacillary dysentery, while air pressure had a negative correlation with the incidence. Ridge regression and hierarchical cluster analysis showed that during 1987-1996, relative humidity, temperatures and air pressure affected the transmission of the bacillary dysentery. During this period, all meteorological factors were divided into three categories. Relative humidity and precipitation belonged to one class, temperature indexes and evaporation belonged to another class, and air pressure was the third class. Meteorological factors have affected the transmission of bacillary dysentery in northeast China. Bacillary dysentery prevention and control would benefit from by giving more consideration to local climate variations.

  4. INVESTIGATION OF THE RELATIONSHIP BETWEEN IONOSPHERIC TEC ANOMALY VARIATIONS AND FAULT TYPES BEFORE THE EARTHQUAKES

    Directory of Open Access Journals (Sweden)

    M. Ulukavak

    2017-11-01

    Full Text Available Earthquakes are natural phenomena that shake the earth and cause many damage. Since the time of arrival of the earthquakes cannot be determined directly, some signs before the earthquake should be examined and interpreted by examining the environmental changes. One of the methods used for this is monitoring the ionospheric total electron content (TEC changes in total electron content unit (TECU. GPS satellites have begun to be used as a means of monitoring ionospheric TEC anomalies before earthquakes since they began to be used as sensors around the world. In this study, three fault type (normal, thrust and strike-slip faulting of 28 earthquakes with a magnitude greater than 7 (Mw and the percentage changes of TEC anomalies before the earthquakes were investigated. The ionospheric TEC anomalies before the earthquake were calculated according to the 15-day running median statistical analysis method. Different solar and geomagnetic indices have been investigated to determine the active space weather conditions and quiet days before and after the earthquake. The TEC anomalies were determined during the quiet days before the earthquake by comparing the ionospheric anomalies that occurred before the earthquake after the determination of quiet days with the indices of the space weather conditions. The results show that there is a relationship between fault type and the earthquake precursor percentage changes and were determined as 47.6 % TECU for regions where normal faulting, 50.4 % TECU for regions where thrust faulting, and 44.2 % TECU for regions where strike-slip faulting occurred, respectively.

  5. Investigation of the Relationship Between Ionospheric TEC Anomaly Variations and Fault Types Before the Earthquakes

    Science.gov (United States)

    Ulukavak, M.; Yalçınkaya, M.

    2017-11-01

    Earthquakes are natural phenomena that shake the earth and cause many damage. Since the time of arrival of the earthquakes cannot be determined directly, some signs before the earthquake should be examined and interpreted by examining the environmental changes. One of the methods used for this is monitoring the ionospheric total electron content (TEC) changes in total electron content unit (TECU). GPS satellites have begun to be used as a means of monitoring ionospheric TEC anomalies before earthquakes since they began to be used as sensors around the world. In this study, three fault type (normal, thrust and strike-slip faulting) of 28 earthquakes with a magnitude greater than 7 (Mw) and the percentage changes of TEC anomalies before the earthquakes were investigated. The ionospheric TEC anomalies before the earthquake were calculated according to the 15-day running median statistical analysis method. Different solar and geomagnetic indices have been investigated to determine the active space weather conditions and quiet days before and after the earthquake. The TEC anomalies were determined during the quiet days before the earthquake by comparing the ionospheric anomalies that occurred before the earthquake after the determination of quiet days with the indices of the space weather conditions. The results show that there is a relationship between fault type and the earthquake precursor percentage changes and were determined as 47.6 % TECU for regions where normal faulting, 50.4 % TECU for regions where thrust faulting, and 44.2 % TECU for regions where strike-slip faulting occurred, respectively.

  6. Investigation of temporal and lateral variations of seismic velocities in south Iceland using ray tracing.

    Science.gov (United States)

    Kjartansson, Einar; Bjarnason, Ingi Th.

    2017-04-01

    Tools for ray-tracing through one dimensional earth models consisting of layers of constant velocity gradients, and continuous values across layers, have been developed. They are used to investigate stability and robustness of earthquake locations and velocity determinations in the South Iceland Lowlands (SIL) a transform seismic zone. These tools will also be used to invert for velocity functions for different regions and time periods, by inverting simultaneously for micro-earthquake source parameters and P and S velocities. Increase of velocity gradient with depth will cause rays with different take-off angles to cross, which can result in focusing and triplication when velocity is plotted versus time. It is therefore important to constrain the velocity solutions to avoid this. Large changes in gradient between adjacent layers causes variability of ray density and geometrical spreading, particularly for rays that turn just below the boundaries. This may create artificial clustering in the depth distribution of micro-earthquake source solutions. Resampling of the velocity functions using cubic spline interpolation can be used to reduce these effects. The software is open source and can be accessed at https://github.com/4dseismic

  7. An investigation into CT radiation dose variations for head examinations on matched equipment

    International Nuclear Information System (INIS)

    Zarb, Francis; Foley, Shane; Toomey, Rachel; Rainford, Louise; Holm, Susanne; Evanoff, Michael G.

    2016-01-01

    This study investigated radiation dose and image quality differences for computed tomography (CT) head examinations across centres with matched CT equipment. Radiation dose records and imaging protocols currently employed across three European university teaching hospitals were collated, compared and coded as Centres A, B and C from specification matched CT equipment models. Patient scans (n = 40) obtained from Centres A and C were evaluated for image quality, based on the visualisation of Commission of European Community (CEC) image quality criteria using visual grading characteristic (VGC) analysis, where American Board of Radiology examiners (n = 11) stated their confidence in identifying anatomical criteria. Mean doses in terms of CT dose index (CTDI vol -mGy) and dose length product (DLP-mGy cm) were as follows: Centre A-33.12 mGy and 461.45 mGy cm; Centre B -101 mGy (base)/32 mGy (cerebrum) and 762 mGy cm and Centre C-71.98 mGy and 1047.26 mGy cm, showing a significant difference (p ≤ 0.05) in DLP across centres. VGC analysis indicated better visualisation of CEC criteria on Centre C images (VGC AUC 0.225). All three imaging protocols are routinely used clinically, and image quality is acceptable in each centre. Clinical centres with identical model CT scanners have variously customised their protocols achieving a range of dose savings and still resulting in clinically acceptable image quality. (authors)

  8. Investigation of 3-D lateral variations on seismic waveform modeling, in preparation for the InSight mission to Mars

    Science.gov (United States)

    Drilleau, M.; Dubois, A.; Blanchette-Guertin, J. F.; Kawamura, T.; Lognonne, P. H.

    2015-12-01

    In 2016, the InSight mission will provide the very first seismic records from Mars after installing a seismometer on the surface of the Red Planet. Obtaining information on the deep 1-D seismic structure of Mars using a single geophysical station will be challenging. However, successful test inversions using body and surface waves have been presented in a preliminary study by Panning et al. (2015). Future investigations need now to focus on inversions making a complete use of the seismic waveform. An important challenge is to investigate the effects of 3-D lateral variations of seismic velocity structures on seismograms. The HOPT (Higher Order Perturbation Theory) code originally developed by P. Lognonné and E. Clévédé (Lognonné, 1991 ; Lognonné and Clévédé, 2002) and based on the perturbation theory allows for the computation of synthetic seismograms in a 3-D Earth. We adapted the code for Mars and computed surface wave synthetics in a 3-D planet, initially only considering the effects of the planet's ellipticity as well as the lateral variations in the depth of the Moho which are known through gravity measurements (e.g. Neumann et al., 2004). Additional constraints from lateral variations in topography will be the focus of future work. These synthetics can be compared to future seismic data in order to identify a suite of Martian internal structure models that best match the data. To do so, we first need to estimate the resolvable parameters concerning the Mars deep interior while considering the 3-D effects, which is the main goal of this study. Furthermore, in preparation for the InSight mission data return phase, the computation of these synthetic (but realistic) seismograms is primordial to test the softwares developed by the InSight Mars Quake and Mars Structure Services (in charge of locating the seismic events, and using them to assess the internal structure of Mars).

  9. Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

    International Nuclear Information System (INIS)

    Williams, S.D.

    1989-01-01

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P 32 labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population

  10. Structural Variation in Bacterial Glyoxalase I Enzymes: Investigation of the Metalloenzyme Glyoxalase I from Clostridium acetobutylicum

    Energy Technology Data Exchange (ETDEWEB)

    Suttisansanee U.; Swaminathan S.; Lau, K.; Lagishetty, S.; Rao, K. N.; Sauder, J. M.; Burley, S. K.; Honek, J. F.

    2011-11-04

    The glyoxalase system catalyzes the conversion of toxic, metabolically produced {alpha}-ketoaldehydes, such as methylglyoxal, into their corresponding nontoxic 2-hydroxycarboxylic acids, leading to detoxification of these cellular metabolites. Previous studies on the first enzyme in the glyoxalase system, glyoxalase I (GlxI), from yeast, protozoa, animals, humans, plants, and Gram-negative bacteria, have suggested two metal activation classes, Zn{sup 2+} and non-Zn{sup 2+} activation. Here, we report a biochemical and structural investigation of the GlxI from Clostridium acetobutylicum, which is the first GlxI enzyme from Gram-positive bacteria that has been fully characterized as to its three-dimensional structure and its detailed metal specificity. It is a Ni{sup 2+}/Co{sup 2+}-activated enzyme, in which the active site geometry forms an octahedral coordination with one metal atom, two water molecules, and four metal-binding ligands, although its inactive Zn{sup 2+}-bound form possesses a trigonal bipyramidal geometry with only one water molecule liganded to the metal center. This enzyme also possesses a unique dimeric molecular structure. Unlike other small homodimeric GlxI where two active sites are located at the dimeric interface, the C. acetobutylicum dimeric GlxI enzyme also forms two active sites but each within single subunits. Interestingly, even though this enzyme possesses a different dimeric structure from previously studied GlxI, its metal activation characteristics are consistent with properties of other GlxI. These findings indicate that metal activation profiles in this class of enzyme hold true across diverse quaternary structure arrangements.

  11. Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

    Energy Technology Data Exchange (ETDEWEB)

    Williams, S.D.

    1989-01-01

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P{sup 32} labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population.

  12. Use of Restriction Fragment Length Polymorphisms to Investigate Strain Variation Within Neisseria Meningitidis.

    Science.gov (United States)

    Williams, Shelley Diane

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty -six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P ^{32} labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analysed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population. This analysis demonstrates the lack of structure within Neisseria meningitidis due primarily to a heterogenous population and the lack of geographic segregation. The potential utility of this technique as a

  13. Using GNSS observations to investigate variations of Pluviometry in the Semi-Arid Brazilian region

    Science.gov (United States)

    Silva, Mario; Fernandes, Rui; Nascimento, Aderson; Petta, Reinaldo; Matschullat, Jörg; Monico, João; Bos, Machiel; Sá, Andre; Barbosa, Marx

    2014-05-01

    The Semi-Arid Brazilian region is the most densely populated, semi-arid region in the world. It is located in the Northeastern part of Brazil and corresponds to approximately 982,563 square kilometers (about 11% of the total Brazilian territory). The temperatures remain nearly uniform throughout the year and are typically tropical, often extremely hot with little interannual variability, exert a strong effect on the potential evapotranspiration, which in turn determine the annual water deficit leading to extensive droughts in some years. The annual rainfall averages between 500 and 800 millimeters and have great climatic variability and an irregular distribution in space and time. Most of the year the region is strongly influenced by the inter-tropical convergence zone which remains in the northern hemisphere near the equator most of the year due to the cold waters of the Atlantic Ocean. The GNSS technique has been established as a valid tool to sense the amount of PWV in the atmosphere. The direct estimated product is the ZTD (Zenith Troposphere Delay) that can be transformed to PWV by knowing the Pressure and Temperature at the station position. However, such values are not always collected together with the GNSS observations, which can force us to limit the analysis to the ZTD directly. In this work we have used data of the existing continuous GNSS (Global Navigation Satellite Systems) stations in the Semi-Arid Brazil to investigate the variability of precipitable water vapor (PWV) in the region. We firstly analysis the accuracy of using global models of pressure and temperature fields to calculate the PWV at the GNSS station locations in the Northeast of Brazil. To do such, we have estimated and compared values of PWV using both global models and local measurements at Natal city, Brazil. The differences provide us a reliable estimate of the error associated with the use of global models to compute the PWV from ZTD measurements for Northeastern Brazil. Secondly

  14. Investigation of dielectric constant variations for Malaysians soil species towards its natural background dose

    Science.gov (United States)

    Jafery, Khawarizmi Mohd; Embong, Zaidi; Khee, Yee See; Haimi Dahlan, Samsul; Tajudin, Saiful Azhar Ahmad; Ahmad, Salawati; Kudnie Sahari, Siti; Maxwell, Omeje

    2018-01-01

    The correlation of natural background gamma radiation and real part of the complex relative permittivity (dielectric constant) for various species Malaysian soils was investigated in this research. The sampling sites were chosen randomly according to soils groups that consist of sedentary, alluvial and miscellaneous soil which covered the area of Batu Pahat, Kluang and Johor Bahru, Johor state of Malaysia. There are 11 types of Malaysian soil species that have been studied; namely Peat, Linau-Sedu, Selangor-Kangkong, Kranji, Telemong-Akob-Local Alluvium, Holyrood-Lunas, Batu Anam-Melaka-Tavy, Harimau Tampoi, Kulai-Yong Peng, Rengam-Jerangau, and Steepland soils. In-situ exposure rates of each soil species were measured by using portable gamma survey meter and ex-situ analysis of real part of relative permittivity was performed by using DAK (Dielectric Assessment Kit assist by network analyser). Results revealed that the highest and the lowest background dose rate were 94 ± 26.28 μR hr-1 and 7 ± 0.67 μR hr-1 contributed by Rengam Jerangau and Peat soil species respectively. Meanwhile, dielectric constant measurement, it was performed in the range of frequency between 100 MHz to 3 GHz. The measurements of each soils species dielectric constant are in the range of 1 to 3. At the lower frequencies in the range of 100 MHz to 600 MHz, it was observed that the dielectric constant for each soil species fluctuated and inconsistent. But it remained consistent in plateau form of signal at higher frequency at range above 600 MHz. From the comparison of dielectric properties of each soil at above 600 MHz of frequency, it was found that Rengam-Jerangau soil species give the highest reading and followed by Selangor-Kangkong species. The average dielectric measurement for both Selangor-Kangkong and Rengam-Jerangau soil species are 2.34 and 2.35 respectively. Meanwhile, peat soil species exhibits the lowest dielectric measurement of 1.83. It can be clearly seen that the pattern

  15. Investigation of Control System and Display Variations on Spacecraft Handling Qualities for Docking with Stationary and Rotating Targets

    Science.gov (United States)

    Jackson, E. Bruce; Goodrich, Kenneth H.; Bailey, Randall E.; Barnes, James R.; Ragsdale, William A.; Neuhaus, Jason R.

    2010-01-01

    This paper documents the investigation into the manual docking of a preliminary version of the Crew Exploration Vehicle with stationary and rotating targets in Low Earth Orbit. The investigation was conducted at NASA Langley Research Center in the summer of 2008 in a repurposed fixed-base transport aircraft cockpit and involved nine evaluation astronauts and research pilots. The investigation quantified the benefits of a feed-forward reaction control system thruster mixing scheme to reduce translation-into-rotation coupling, despite unmodeled variations in individual thruster force levels and off-axis center of mass locations up to 12 inches. A reduced rate dead-band in the phase-plane attitude controller also showed some promise. Candidate predictive symbology overlaid on a docking ring centerline camera image did not improve handling qualities, but an innovative attitude status indicator symbol was beneficial. The investigation also showed high workload and handling quality problems when manual dockings were performed with a rotating target. These concerns indicate achieving satisfactory handling quality ratings with a vehicle configuration similar to the nominal Crew Exploration Vehicle may require additional automation.

  16. Using proteomic analysis to investigate uniconazole-induced phytohormone variation and starch accumulation in duckweed (Landoltia punctata).

    Science.gov (United States)

    Huang, Mengjun; Fang, Yang; Liu, Yang; Jin, Yanling; Sun, Jiaolong; Tao, Xiang; Ma, Xinrong; He, Kaize; Zhao, Hai

    2015-09-15

    Duckweed (Landoltia punctata) has the potential to remediate wastewater and accumulate enormous amounts of starch for bioethanol production. Using systematical screening, we determined that the highest biomass and starch percentage of duckweed was obtained after uniconazole application. Uniconazole contributes to starch accumulation of duckweed, but the molecular mechanism is still unclear. To elucidate the mechanisms of high starch accumulation, in the study, the responses of L. punctata to uniconazole were investigated using a quantitative proteomic approach combined with physiological and biochemical analysis. A total of 3327 proteins were identified. Among these identified proteins, a large number of enzymes involved in endogenous hormone synthetic and starch metabolic pathways were affected. Notably, most of the enzymes involved in abscisic acid (ABA) biosynthesis showed up-regulated expression, which was consistent with the content variation. The increased endogenous ABA may up-regulate expression of ADP-glucose pyrophosphorylase to promote starch biosynthesis. Importantly, the expression levels of several key enzymes in the starch biosynthetic pathway were up-regulated, which supported the enzymatic assay results and may explain why there is increased starch accumulation. These generated data linked uniconazole with changes in expression of enzymes involved in hormone biosynthesis and starch metabolic pathways and elucidated the effect of hormones on starch accumulation. Thus, this study not only provided insights into the molecular mechanisms of uniconazole-induced hormone variation and starch accumulation but also highlighted the potential for duckweed to be feedstock for biofuel as well as for sewage treatment.

  17. Computerized system to measure interproximal alveolar bone levels in epidemiologic, radiographic investigations. II. Intra- and inter-examinar variation study

    Energy Technology Data Exchange (ETDEWEB)

    Wouters, F.R.; Frithiof, L.; Soeder, P.Oe.; Hellden, L.; Lavstedt, S.; Salonen, L.

    1988-01-01

    The study was aimed at analyzing intra- and inter-examiner variations in computerized measurement and in non-measurability of alveolar bone level in a cross-sectional, epidemiologic material. At each interproximal tooth surface, alveolar bone height in percentage of root length (B/R) and tooth length (B/T) were determined twice by one examiner and once by a second examiner from X5-magnified periapical radiographs. The overall intra- and inter-examiner variations in measurement were 2.85% and 3.84% of root length and 1.97% and 2.82% of tooth length, respectively. The varations were different for different tooth groups and for different degrees of severity of marginal periodontitis. The overall proportions on non-measurable tooth surfaces varied with examiner from 32% to 39% and from 43% to 48% of the available interproximal tooth surfaces for B/R and B/T, respectively. With regard to the level of reliability, the computerized method reported is appropriate to cross-sectional, epidemiologic investigations from radiographs.

  18. A mathematical representation of an advanced helicopter for piloted simulator investigations of control system and display variations

    Science.gov (United States)

    Aiken, E. W.

    1980-01-01

    A mathematical model of an advanced helicopter is described. The model is suitable for use in control/display research involving piloted simulation. The general design approach for the six degree of freedom equations of motion is to use the full set of nonlinear gravitational and inertial terms of the equations and to express the aerodynamic forces and moments as the reference values and first order terms of a Taylor series expansion about a reference trajectory defined as a function of longitudinal airspeed. Provisions for several different specific and generic flight control systems are included in the model. The logic required to drive various flight control and weapon delivery symbols on a pilot's electronic display is also provided. Finally, the model includes a simplified representation of low altitude wind and turbulence effects. This model was used in a piloted simulator investigation of the effects of control system and display variations for an attack helicopter mission.

  19. Efficient Usage of Dense GNSS Networks in Central Europe for the Visualization and Investigation of Ionospheric TEC Variations.

    Science.gov (United States)

    Nykiel, Grzegorz; Zanimonskiy, Yevgen M; Yampolski, Yuri M; Figurski, Mariusz

    2017-10-10

    The technique of the orthogonal projection of ionosphere electronic content variations for mapping total electron content (TEC) allows us to visualize ionospheric irregularities. For the reconstruction of global ionospheric characteristics, numerous global navigation satellite system (GNSS) receivers located in different regions of the Earth are used as sensors. We used dense GNSS networks in central Europe to detect and investigate a special type of plasma inhomogeneities, called travelling ionospheric disturbances (TID). Such use of GNSS sensors allows us to reconstruct the main TID parameters, such as spatial dimensions, velocities, and directions of their movement. The paper gives examples of the restoration of dynamic characteristics of ionospheric irregularities for quiet and disturbed geophysical conditions. Special attention is paid to the dynamics of ionospheric disturbances stimulated by the magnetic storms of two St. Patrick's Days (17 March 2013 and 2015). Additional opportunities for the remote sensing of the ionosphere with the use of dense regional networks of GNSS receiving sensors have been noted too.

  20. Using an epidemiological model to investigate unwarranted variation: the case of ventilation tubes for otitis media with effusion in England.

    Science.gov (United States)

    Schang, Laura; De Poli, Chiara; Airoldi, Mara; Morton, Alec; Bohm, Natalie; Lakhanpaul, Monica; Schilder, Anne; Bevan, Gwyn

    2014-10-01

    To investigate unwarranted variation in ventilation tube insertions for otitis media with effusion in children in England. This procedure is known to be 'overused' from clinical audits, as only one in three ventilation tube insertions conforms to the appropriateness criteria of the National Institute for Health and Care Excellence (NICE); but audits cannot identify the scale of 'underuse' - i.e. patients who would benefit but are not treated. To explore both 'underuse' and 'overuse' of ventilation tubes for otitis media with effusion, we developed an epidemiological model based on: definitions of children with otitis media with effusion expected to benefit from ventilation tubes according to NICE guidance; epidemiological and clinical information from a systematic review; and expert judgement. A range of estimates was derived using Monte Carlo simulation and compared with the number of ventilation tubes provided in the English National Health Service in 2010. About 32,200 children in England would be expected to benefit from ventilation tubes for otitis media with effusion per year (between 20,411 and 45,231 with 90% certainty). The observed number of ventilation tubes for otitis media with effusion-associated diagnoses was 16,824. The expected population capacity to benefit from ventilation tubes for otitis media with effusion based on NICE guidance appeared to exceed, by far, the number of ventilation tubes provided in the English National Health Service. So, while there is known 'overuse', there also may be substantial 'underuse' of ventilation tubes for otitis media with effusion if NICE criteria were applied. Future investigations of unwarranted variation should, therefore, not only focus on the patients who are treated but also consider the potential for benefit at the population level. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  1. The investigation of spatiotemporal variations of land surface temperature based on land use changes using NDVI in southwest of Iran

    Science.gov (United States)

    Fathizad, Hassan; Tazeh, Mahdi; Kalantari, Saeideh; Shojaei, Saeed

    2017-10-01

    Land use changes can bring about changes in land surface temperature (LST) which is influenced by climatic conditions and physical characteristics of the land surface. In this study, spatiotemporal variations of land surface temperature have been investigated in the desert area of Dasht-e-Abbas, Ilam, based on a variety of land use changes. The investigated periods for the study include 1990, 2000 and 2010 using Landsat image data. First, in mapping land use we used the Fuzzy ARTMAP Neural Network Classification method followed by determination of the NDVI Index to estimate land surface temperature. The results show an increase in LST in areas where degradation, land use and land cover changes have occurred. In 1990, 2000 and 2010, the average land surface temperature of the Fair Rangelands was 26.72 °C, 30.06 °C and 30.95 °C, respectively. This rangeland has been reduced by about 5%. For poor rangelands, the average LSTs were 26.95, 32.83 and 34.49 Cº, respectively which had a 18% reduction. In 1990, 2000 and 2010, the average land surface temperatures of agricultural lands were 24.31 °C, 27.87 °C and 28.61 °C, respectively which has been an increasing trend. The reason can be attributed to changes in cropping patterns of the study area.

  2. Triarchic Psychopathy Dimensions in Chimpanzees (Pan troglodytes: Investigating Associations with Genetic Variation in the Vasopressin Receptor 1A Gene

    Directory of Open Access Journals (Sweden)

    Robert D. Latzman

    2017-07-01

    Full Text Available Vasopressin is a neuropeptide known to be associated with the development and evolution of complex socio-emotional behaviors including those relevant to psychopathic personality. In both humans and chimpanzees, recent research suggests a strong genetic contribution to individual variation in psychopathic traits. To date, however, little is known concerning specific genes that might explain the observed heritability of psychopathy. In a relatively large sample of captive chimpanzees (N = 164, the current study thus sought to investigate gene-environment associations between triarchic psychopathy dimensions (i.e., disinhibition, meanness, and boldness and (1 early social rearing experiences and (2 polymorphisms in the promoter region of the V1A receptor gene (AVPR1A. Among chimpanzees raised by their biological conspecific mothers, AVPR1A was found to uniquely explain variability in disinhibition and in sex-specific ways for boldness and a total psychopathy score; however, in contrast, no significant associations were found between AVPR1A and any of the triarchic psychopathy dimensions in chimpanzees raised the first 3 years of life in a human nursery. Thus, when considered in its entirety, results suggest an important contributory influence of V1A receptor genotype variation in the explanation of the development of psychopathy under some but not all early rearing conditions. Results of the current study provide additional support for the assertion that psychopathic tendencies are rooted in basic, evolutionarily-meaningful dispositions, and provide support for a primate-translational operationalization of key neurobehavioral constructs relevant both to psychopathy and to broader forms of psychopathology.

  3. Investigating the Variation of Volatile Compound Composition in Maotai-Flavoured Liquor During Its Multiple Fermentation Steps Using Statistical Methods

    Directory of Open Access Journals (Sweden)

    Zheng-Yun Wu

    2016-01-01

    Full Text Available The use of multiple fermentations is one of the most specific characteristics of Maotai-flavoured liquor production. In this research, the variation of volatile composition of Maotai-flavoured liquor during its multiple fermentations is investigated using statistical approaches. Cluster analysis shows that the obtained samples are grouped mainly according to the fermentation steps rather than the distillery they originate from, and the samples from the first two fermentation steps show the greatest difference, suggesting that multiple fermentation and distillation steps result in the end in similar volatile composition of the liquor. Back-propagation neural network (BNN models were developed that satisfactorily predict the number of fermentation steps and the organoleptic evaluation scores of liquor samples from their volatile compositions. Mean impact value (MIV analysis shows that ethyl lactate, furfural and some high-boiling-point acids play important roles, while pyrazine contributes much less to the improvement of the flavour and taste of Maotai-flavoured liquor during its production. This study contributes to further understanding of the mechanisms of Maotai-flavoured liquor production.

  4. Investigation of spatial and historical variations of air pollution around an industrial region using trace and macro elements in tree components.

    Science.gov (United States)

    Odabasi, Mustafa; Tolunay, Doganay; Kara, Melik; Ozgunerge Falay, Ezgi; Tuna, Gizem; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Elbir, Tolga

    2016-04-15

    Several trace and macro elements (n=48) were measured in pine needle, branch, bark, tree ring, litter, and soil samples collected at 27 sites (21 industrial, 6 background) to investigate their spatial and historical variation in Aliaga industrial region in Turkey. Concentrations generally decreased with distance from the sources and the lowest ones were measured at background sites far from major sources. Spatial distribution of anthropogenic trace elements indicated that their major sources in the region are the iron-steel plants, ship-breaking activities and the petroleum refinery. Patterns of 40 elements that were detected in most of the samples were also evaluated to assess their suitability for investigation of historical variations. Observed increasing trends of several trace and macro elements (As, Cr, Fe, Mo, Ni, V, Cu, Pb, Sb, Sn, and Hg) in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. It was shown that lanthanides (La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb) could also be used for the investigation of historical variations due to specific industrial emissions (i.e., petroleum refining). Results of the present study showed that tree components, litter, and soil could be used to determine the spatial variations of atmospheric pollution in a region while tree rings could be used to assess the historical variations. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Investigation of spatial and historical variations of air pollution around an industrial region using trace and macro elements in tree components

    Energy Technology Data Exchange (ETDEWEB)

    Odabasi, Mustafa, E-mail: mustafa.odabasi@deu.edu.tr [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, 35160 Buca, Izmir (Turkey); Tolunay, Doganay [Department of Forestry Engineering, Faculty of Forestry, Istanbul University, 34470 Sariyer, Istanbul (Turkey); Kara, Melik; Ozgunerge Falay, Ezgi; Tuna, Gizem; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Elbir, Tolga [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, 35160 Buca, Izmir (Turkey)

    2016-04-15

    Several trace and macro elements (n = 48) were measured in pine needle, branch, bark, tree ring, litter, and soil samples collected at 27 sites (21 industrial, 6 background) to investigate their spatial and historical variation in Aliaga industrial region in Turkey. Concentrations generally decreased with distance from the sources and the lowest ones were measured at background sites far from major sources. Spatial distribution of anthropogenic trace elements indicated that their major sources in the region are the iron-steel plants, ship-breaking activities and the petroleum refinery. Patterns of 40 elements that were detected in most of the samples were also evaluated to assess their suitability for investigation of historical variations. Observed increasing trends of several trace and macro elements (As, Cr, Fe, Mo, Ni, V, Cu, Pb, Sb, Sn, and Hg) in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. It was shown that lanthanides (La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb) could also be used for the investigation of historical variations due to specific industrial emissions (i.e., petroleum refining). Results of the present study showed that tree components, litter, and soil could be used to determine the spatial variations of atmospheric pollution in a region while tree rings could be used to assess the historical variations. - Highlights: • Iron-steel plants and refinery are the major trace element emitters in Aliaga region. • Tree components, litter and soil reflected the spatial variations of trace elements. • Elements in tree rings represented the historical variations in air pollution.

  6. Investigating ethnic variations in reporting of psychotic symptoms: a multiple-group confirmatory factor analysis of the Psychosis Screening Questionnaire.

    Science.gov (United States)

    Heuvelman, Hein; Nazroo, James; Rai, Dheeraj

    2018-03-12

    Epidemiological evidence suggests risk for psychosis varies with ethnicity in Western countries. However, there is little evidence to date on the cross-cultural validity of screening instruments used for such comparisons. Combining two existing UK population-based cohorts, we examined risk for reporting psychotic symptoms across White British (n = 3467), White Irish (n = 851), Caribbean (n = 1899), Indian (n = 2590), Pakistani (n = 1956) and Bangladeshi groups (n = 1248). We assessed the psychometric properties of the Psychosis Screening Questionnaire (PSQ) with a multiple-group confirmatory factor analysis, assessing the equivalence of factor loadings, response thresholds and residual variances in an analysis of measurement non-invariance. Compared with prevalence among British Whites (5.4%), the prevalence of self-reported psychotic symptoms was greater in the Caribbean group (12.7%, adjusted OR = 2.38 [95% CI 1.84-3.07]). Prevalence was also increased among Pakistani individuals (8.3%, adjusted OR = 1.36 [1.01-1.84]) although this difference was driven by a greater likelihood of reporting paranoid symptoms. PSQ items for thought interference, strange experience and hallucination were measured in equivalent ways across ethnic groups. However, our measurement models suggested that paranoid symptoms were measured less reliably among ethnic minorities than among British Whites and appeared to exaggerate latent differences between Pakistani and White British groups when measurement non-invariance was not accounted for. Notwithstanding evidence for measurement non-invariance, the greater risk for reporting psychotic symptoms among Caribbean individuals is unlikely to be an artefact of measurement. Greater residual variance in the recording of paranoid symptoms among ethnic minority respondents warrants caution in using this item to investigate ethnic variation in psychosis risk.

  7. The effect of genetic variation in the type 1 deiodinase gene on the inter-individual variation in serum thyroid hormone levels. An investigation in healthy Danish twins

    DEFF Research Database (Denmark)

    van der Deure, Wendy M; Hansen, Pia Skov; Peeters, Robin P

    2009-01-01

    Introduction: Genetic factors have a considerable influence on serum thyroid hormone levels. The C785T and A1814G polymorphisms, located in the 3' untranslated region of the type 1 deiodinase (D1) gene have been associated with serum FT4 and rT3 levels. Objective: In healthy Danish twins, we...... examined the association of these polymorphisms with serum thyroid hormone levels and determined the proportion of genetic influence explained by these variants. We analyzed the underlying functional mechanism by performing mRNA stability measurements and analyzed the effect of these variants on D1......-785T allele had 3.8% higher FT4 and 14.3 % higher rT3 levels, resulting in a lower T3/T4 and T3/rT3 ratio and a higher rT3/T4 ratio. This polymorphism explained 0.87% and 1.79%, respectively, of the variation in serum FT4 and rT3. The D1-A1814G polymorphism was not associated with serum thyroid hormone...

  8. The effect of genetic variation in the type 1 deiodinase gene on the inter-individual variation in serum thyroid hormone levels. An investigation in healthy Danish twins

    DEFF Research Database (Denmark)

    van der Deure, Wendy M; Hansen, Pia Skov; Peeters, Robin P

    2008-01-01

    Introduction: Genetic factors have a considerable influence on serum thyroid hormone levels. The C785T and A1814G polymorphisms, located in the 3' untranslated region of the type 1 deiodinase (D1) gene have been associated with serum FT4 and rT3 levels. Objective: In healthy Danish twins, we...... examined the association of these polymorphisms with serum thyroid hormone levels and determined the proportion of genetic influence explained by these variants. We analyzed the underlying functional mechanism by performing mRNA stability measurements and analyzed the effect of these variants on D1......-785T allele had 3.8% higher FT4 and 14.3 % higher rT3 levels, resulting in a lower T3/T4 and T3/rT3 ratio and a higher rT3/T4 ratio. This polymorphism explained 0.87% and 1.79%, respectively, of the variation in serum FT4 and rT3. The D1-A1814G polymorphism was not associated with serum thyroid hormone...

  9. Investigation of reactivity variations of the Isfahan MNSR reactor due to variations in the thickness of the core top beryllium layer using WIMSD and MCNP codes

    Directory of Open Access Journals (Sweden)

    A Shirani

    2010-12-01

    Full Text Available In this work, the Isfahan Miniature Neutron Source Reactor (MNSR is first simulated using the WIMSD code, and its fuel burn-up after 7 years of operation ( when the reactor was revived by adding a 1.5 mm thick beryllium shim plate to the top of its core and also after 14 years of operation (total operation time of the reactor is calculated. The reactor is then simulated using the MCNP code, and its reactivity variation due to adding a 1.5 mm thick beryllium shim plate to the top of the reactor core, after 7 years of operation, is calculated. The results show good agreement with the available data collected at the revival time. Exess reactivity of the reactor at present time (after 14 years of operation and after 7 years of the the reactor revival time is also determined both experimentally and by calculation, which show good agreement, and indicate that at the present time there is no need to add any further beryllium shim plate to the top of the reactor core. Furthermore, by adding more beryllium layers with various thicknesses to the top of the reactor core, in the input program of the MCNP program, reactivity value of these layers is calculated. From these results, one can predict the necessary beryllium thickness needed to reach a desired reactivity in the MNSR reactor.

  10. Using stable isotopes of carbon to investigate the seasonal variation of carbon transfer in a northwestern Arkansas cave

    Science.gov (United States)

    Knierim, Katherine J.; Pollock, Erik; Hays, Phillip D.; Khojasteh, Jam

    2015-01-01

    -to-month variations in temperature and precipitation and provided insight into the sources of carbon in the cave. Stable carbon isotope ratios provided an effective tool to explore carbon transfer from the soil zone and into the cave, identify carbon sources in the cave, and investigate how seasonality affected the transfer of carbon in a shallow karst system.

  11. Near-infrared monitoring of roller compacted ribbon density: Investigating sources of variation contributing to noisy spectral data.

    Science.gov (United States)

    Crowley, Mary Ellen; Hegarty, Avril; McAuliffe, Michael A P; O'Mahony, Graham E; Kiernan, Luke; Hayes, Kevin; Crean, Abina M

    2017-05-01

    The aim of this study was to highlight how variability in roller compacted ribbon quality can impact on NIR spectral measurement and to propose a simple method of data selection to remove erroneous spectra. The use of NIR spectroscopy for monitoring ribbon envelope density has been previously demonstrated, however to date there has been limited discussion as to how spectral data sets can contain erroneous outliers due to poor sample presentation to the NIR probes. In this study compacted ribbon of variable quality was produced from three separate blends of microcrystalline cellulose (MCC)/lactose/magnesium stearate at 8 Roll Force settings (2-16kN/cm). The three blends differed only in the storage conditions of MCC prior to blending and compaction. MCC sublots were stored at ambient (41% RH/20°C), low humidity (11% RH/20°C) and high humidity (75% RH/40°C) conditions prior to blending. Ribbon envelope density was measured and ribbon NIR spectral data was acquired at line using a multi-probe spectrometer (MultiEye™ NIR). Initial inspection of the at-line NIR spectral data set showed a large degree of variability which indicated that some form of data cleaning was required. The source of variability in spectral measurements was investigated by subjective visual examination and by statistical analysis. Spectral variability was noted due to the storage conditions of MCC prior to compaction, Roll Force settings and between individual ribbon samples sampled at a set Roll Force/Blend combination. Variability was also caused by ribbon presentation to probes, such as differences in the presentation of broken, curved and flat intact ribbons. Based on the subjective visual examination of data, a Visual Discard method was applied and was found to be particularly successful for blends containing MCC stored at ambient and low humidity. However the Visual Discard method of spectra cleaning is subjective and therefore a non-subjective method capable of screening for erroneous

  12. Investigation of electronic structure and electron affinity in chalcogene hexafluoride series by the discrete variational Xα-method

    International Nuclear Information System (INIS)

    Gutsev, G.L.; Klyagina, A.P.; AN SSSR, Moscow. Inst. Obshchej i Neorganicheskoj Khimii)

    1982-01-01

    Using the discrete variational Xα-method electronic structure of sulfur, selenium and tellurium hexafluorides is calculated. A connection of certain chemical properties with the calculated distribution of electron density is discussed. An explanation of the change of electron affinity in the series of the compounds is suggested

  13. Investigation of Interfraction Variations of MammoSite Balloon Applicator in High-Dose-Rate Brachytherapy of Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Kim, Yongbok; Johnson, Mark M.S.; Trombetta, Mark G.; Parda, David S.; Miften, Moyed

    2008-01-01

    Purpose: To measure the interfraction changes of the MammoSite applicator and evaluate their dosimetric effect on target coverage and sparing of organs at risk. Methods and Materials: A retrospective evaluation of the data from 19 patients who received 10 fractions (34 Gy) of high-dose-rate partial breast irradiation was performed. A computed tomography-based treatment plan was generated for Fraction 1, and a computed tomography scan was acquired just before the delivery of each fraction to ensure a consistent shape of the balloon. The eccentricity, asymmetry, and planning target volume (PTV) for plan evaluation purposes (PTV E VAL), as well as trapped air gaps, were measured for all patients. Furthermore, 169 computed tomography-based treatment plans were retrospectively generated for Fractions 2-10. Interfraction dosimetric variations were evaluated using the %PTV E VAL coverage, target dose homogeneity index, target dose conformal index, and maximum doses to the organs at risks. Results: The average variation of eccentricity and asymmetry from Fraction 1 values of 3.5% and 1.1 mm was -0.4% ± 1.6% and -0.1 ± 0.6 mm. The average trapped air gap volume was dramatically reduced from before treatment (3.7 cm 3 ) to Fraction 1 (0.8 cm 3 ). The PTV E VAL volume change was insignificant. The average variation for the %PTV E VAL, target dose homogeneity, and target dose conformal index from Fraction 1 values of 94.7%, 0.64, and 0.85 was 0.15% ± 2.4%, -0.35 ± 2.4%, and -0.34 ± 4.9%, respectively. The average Fraction 1 maximum skin and ipsilateral lung dose of 3.2 Gy and 2.0 Gy varied by 0.08 ± 0.47 and -0.16 ± 0.29 Gy, respectively. Conclusion: The interfraction variations were patient specific and fraction dependent. Although the average interfraction dose variations for the target and organs at risk were not clinically significant, the maximum variations could be clinically significant

  14. Variation of brine compositions resulting from flow from matrix or fracture permeability, investigated by high pressure laboratory experiments

    Science.gov (United States)

    Poszwa, A. C.; Coleman, M. L.; Pouya, A.; Ader, M.; Bounenni, A.

    2003-04-01

    Planning oil production from a chalk reservoir oilfield is difficult because the matrix usually has low permeability despite its high porosity. Most oil is thought to come from fracture porosity but the matrix contribution should increase as compaction occurs during production. To better understand the respective contributions from matrix and fracture, we studied the geochemical characteristics of fluids using high-pressure brine flow experiments on chalk cores. During the experiment axial load was changed relative to confining pressure to induce fractures and to close them again. We used chlorine stable isotope variations to study fluid pathway, because chlorine is a chemically conservative element in sedimentary systems and its isotopes fractionate only with physical processes like diffusion or adsorption that could occur mainly in the chalk matrix. A first experiment was performed on a very porous chalk from Henley (on-shore UK) and using a low-salinity brine. Large variations of brine Cl isotope composition were observed (from -0.56 to +0.08 per mil). The variations were correlated positively with the brine flux through the chalk and the permeability of the rock, both parameters controlled by the rock fracturing. A second experiment used brine with salinity similar to that of seawater. In this case, chemical and isotopic variations were not significant. From the beginning, the chalk structure seems to have been destroyed very quickly (induced fracture porosity collapsed) possibly because of the fluid nature, so that whatever pressure was applied, the permeability did not change significantly. Using Valhall reservoir chalk (offshore Norwegian North Sea) and fluid half the salinity of seawater in a third experiment, we obtained a large range of permeabilities. Brine isotopic trends were very similar on average to those of the first experiment even though variations were smaller (Cl isotopes from -0.09 to +0.29 per mil) and not significantly correlated simply to

  15. Investigating the patterns and determinants of seasonal variation in vitamin D status in Australian adults: the Seasonal D Cohort Study

    Directory of Open Access Journals (Sweden)

    Laura King

    2016-08-01

    Full Text Available Abstract Background Vitamin D status generally varies seasonally with changing solar UVB radiation, time in the sun, amount of skin exposed, and, possibly, diet. The Seasonal D Study was designed to quantify the amplitude and phase of seasonal variation in the serum concentration of 25-hydroxyvitamin D, (25OHD and identify the determinants of the amplitude and phase and those of inter-individual variability in seasonal pattern. Methods The Seasonal D Study collected data 2-monthly for 12 months, including demographics, personal sun exposure using a diary and polysulphone dosimeters over 7 days, and blood for serum 25(OHD concentration. The study recruited 333 adults aged 18–79 years living in Canberra (35°S, n = 168 and Brisbane (27°South, n = 165, Australia. Discussion We report the study design and cohort description for the Seasonal D Study. The study has collected a wealth of data to examine inter- and intra-individual seasonal variation in vitamin D status and serum 25(OHD levels in Australian adults.

  16. An investigation of the co-variation in circulating levels of a large number of environmental contaminants.

    Science.gov (United States)

    Lampa, Erik; Lind, Lars; Hermansson, Anna Bornefalk; Salihovic, Samira; van Bavel, Bert; Lind, P Monica

    2012-09-01

    We are daily exposed to many different environmental contaminants. Mixtures of these contaminants could act together to induce more pronounced effects than the sum of the individual contaminants. To evaluate the effects of such mixtures, it is of importance to assess the co-variance amongst the contaminants. Thirty-seven environmental contaminants representing different classes were measured in blood samples from 1016 individuals aged 70 years. Hierarchical cluster analysis and principal component analysis were used to assess the co-variation among the contaminants. Within each identified cluster, possible marker contaminants were sought for. We validated our findings using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 study. Two large clusters could be identified, one representing low/medium chlorinated polychlorinated biphenyls (PCBs) (≤6 chlorine atoms), as well as two pesticides and one representing medium/high chlorinated PCBs (≥6 chlorine atoms). PCBs 118 and 153 could be used as markers for the low/medium chlorinated cluster and PCBs 170 and 209 could be used as markers for the medium/high chlorinated cluster. This pattern was similar to data from the NHANES study. Apart from the PCBs, little co-variation was seen among the contaminants. Thus, a large number of chemicals have to be measured to adequately identify mixtures of environmental contaminants.

  17. Investigation on a system to collect water vapor from the air, for the analysis of natural isotopic variation

    International Nuclear Information System (INIS)

    Foloni, L.L.

    1975-01-01

    The development of a system to collect water vapor from air for isotopic composition analysis and its natural variation is studied. The system consists of a molecular sieve type 4A, without cooling agent and permits the choice of a sampling time varying from a few minutes to many hours through the control of the admission vapor flux. The system has been compared with other existing systems, having shown excellent performance for the collection of samples for D/H ratio analysis, with errors of the order of +- -+ 3.0 0 /oo and +- -+ 0.6 0 /oo in the delta sub(D) 0 /oo and delta 18 0 0 /oo ratios, respectively [pt

  18. Peptidomic investigation ofNeoponera villosavenom by high-resolution mass spectrometry: seasonal and nesting habitat variations.

    Science.gov (United States)

    Cologna, Camila Takeno; Rodrigues, Renata Santos; Santos, Jean; de Pauw, Edwin; Arantes, Eliane Candiani; Quinton, Loïc

    2018-01-01

    Advancements in proteomics, including the technological improvement in instrumentation, have turned mass spectrometry into an indispensable tool in the study of venoms and toxins. In addition, the advance of nanoscale liquid chromatography coupled to nanoelectrospray mass spectrometry allows, due to its high sensitivity, the study of venoms from species previously left aside, such as ants. Ant venoms are a complex mixture of compounds used for defense, predation or communication purposes. The venom from Neoponera ants, a genus restricted to Neotropical regions, is known to have cytolytic, hemolytic, antimicrobial and insecticidal activities. Moreover, venoms from several Neoponera species have been compared and differences in their toxicity related to nesting habitat variation were reported. Therefore, the present study aimed to perform a deep peptidomic analysis of Neoponera villosa venom and a comparison of seasonal and nesting habitat variations using high-resolution mass spectrometry. Specimens of N. villosa ants were captured in Panga Natural Reserve (Uberlândia, MG, Brazil) from arboreal and ground-dwelling nests during summer and winter time. The venom glands were dissected, pooled and disrupted by ultra-sonic waves. The venom collected from different habitats (arboreal and ground-dwelling) and different seasons (summer and winter) was injected into a nanoACQUITY ULPC hyphened to a Q-Exactive Orbitrap mass spectrometer. The raw data were analyzed using PEAKS 7. The results showed a molecular diversity of more than 500 peptides among these venoms, mostly in the mass range of 800-4000 Da. Mutations and post-translational modifications were described and differences among the venoms were observed. Part of the peptides matched with ponericins, a well-known antimicrobial peptide family. In addition, smaller fragments related to ponericins were also identified, suggesting that this class of antimicrobial peptide might undergo enzymatic cleavages. There are

  19. Experimental Investigation of the Variation of Concrete Pores under the Action of Freeze-Thaw Cycles by Using X-Ray CT

    Directory of Open Access Journals (Sweden)

    Jie Yuan

    2014-01-01

    Full Text Available The variation of concrete pores under the action of freeze-thaw cycles was investigated experimentally by using the X-ray CT. Firstly, the statistical characteristics of pores of concrete specimens were obtained by using the X-ray image analysis. Secondly, the variation of porosity and pore volume of concrete pores were analyzed and discussed by comparing with above characteristics. Thirdly, the failure process of the concrete specimens acted by the freeze-thaw cycles was investigated by scanning the interior of concrete specimens. The results showed that the pore volumes of concrete pores whose volumes were located at the interval [0.5 mm3, 20 mm3] have no big variation in both the amounts and volume of concrete pores, while others were found to have huge change during the process of experiment. The extent of damage acted by the repeated freezing and thawing gradually ranged from surface to complete disintegration of the interior of concrete specimens after 30 cycles of freeze-thaw acting.

  20. Geographic Variation in Treatment and Outcomes Among Patients With AMI: Investigating Urban-Rural Differences Among Hospitalized Patients.

    Science.gov (United States)

    Bechtold, Daniel; Salvatierra, G G; Bulley, Emily; Cypro, Alex; Daratha, Kenn B

    2017-04-01

    The value of early invasive revascularization for patients suffering acute myocardial infarction (AMI) is well known. However, access to revascularization services varies geographically and demographically. Previous studies have not examined the influence of rural residence on revascularization rates and outcomes among patients hospitalized with AMI. Our retrospective cohort study included patients hospitalized in Washington State with a primary diagnosis of AMI from 2009 to 2012. Urban or rural residence was determined using rural-urban commuting area (RUCA) codes. Multivariable models were used to evaluate geographic variation in rates of invasive versus medical management, in-hospital mortality, rehospitalization, and subsequent revascularization procedures. Our study included 25,156 urban dwellers and 2,770 rural residents. Adjusted models found rural patients to be at increased odds of undergoing invasive revascularization during the initial episode of AMI care (OR = 1.11; 95% CI: 1.01-1.21; P = .02) compared to urban dwelling patients. Rural patients were more likely to be transferred for care (OR = 4.28; 95% CI: 3.93-4.66; P urban cohort. We found no significant geographic cohort differences in in-hospital mortality or subsequent revascularization rates. Our findings suggest that despite limited access to cardiac care facilities, rural patients are accessing revascularization services. However, rural residents are more likely to undergo CABG during their index admission. High transfer rates suggest that rural regions rely on effective transfer networks to access invasive cardiac services. © 2015 National Rural Health Association.

  1. Investigation of Primary Factors Affecting the Variation of Modeled Oak Pollen Concentrations: A Case Study for Southeast Texas in 2010

    Science.gov (United States)

    Jeon, Wonbae; Choi, Yunsoo; Roy, Anirban; Pan, Shuai; Price, Daniel; Hwang, Mi-Kyoung; Kim, Kyu Rang; Oh, Inbo

    2018-02-01

    Oak pollen concentrations over the Houston-Galveston-Brazoria (HGB) area in southeastern Texas were modeled and evaluated against in-situ data. We modified the Community Multi-scale Air Quality (CMAQ) model to include oak pollen emission, dispersion, and deposition. The Oak Pollen Emission Model (OPEM) calculated gridded oak pollen emissions, which are based on a parameterized equation considering a plant-specific factor ( C e ), surface characteristics, and meteorology. The simulation period was chosen to be February 21 to April 30 in the spring of 2010, when the observed monthly mean oak pollen concentrations were the highest in six years (2009-2014). The results indicated C e and meteorology played an important role in the calculation of oak pollen emissions. While C e was critical in determining the magnitude of oak pollen emissions, meteorology determined their variability. In particular, the contribution of the meteorology to the variation in oak pollen emissions increased with the oak pollen emission rate. The evaluation results using in-situ surface data revealed that the model underestimated pollen concentrations and was unable to accurately reproduce the peak pollen episodes. The model error was likely due to uncertainty in climatology-based C e used for the estimation of oak pollen emissions and inaccuracy in the wind fields from the Weather Research and Forecast (WRF) model.

  2. Investigation into the Mpemba Effect: Variation in the Freezing Time of Water Dependent on Initial Temperature and Purity

    Science.gov (United States)

    Thvedt, Ingrid; Roseberry, Martha; Lehman, Susan

    2009-03-01

    The observation that hot water sometimes appears to freeze more quickly than cold water, known as the Mpemba effect, has generated vigorous debate. Prior research [1] into the Mpemba effect has resulted in conflicting results, due to a variety of observation techniques, multiple definitions of freezing, and different water treatments. To clarify the previous results, we have tested multiple types of water and improved the sample monitoring. During cooling and freezing, each 50 g water sample is continually monitored by three thermistors at different depths. Samples of tap, distilled, and nanopure water were heated, heated and cooled, or boiled before being frozen. We monitor the time to reach freezing, the duration of freezing, and the total time to reach -7^oC. We observe the Mpemba effect most consistently in the length of the freezing transition in tap water. Observations of temperature variation during freezing will also be presented. [1] See the review by M. Jeng, Am.J.Phys. 74 514 (2006).

  3. Investigating glycemic potential of rice by unraveling compositional variations in mature grain and starch mobilization patterns during seed germination.

    Science.gov (United States)

    Guzman, Maria Krishna de; Parween, Sabiha; Butardo, Vito M; Alhambra, Crisline Mae; Anacleto, Roslen; Seiler, Christiane; Bird, Anthony R; Chow, Chung-Ping; Sreenivasulu, Nese

    2017-07-19

    Rice lines with slower starch digestibility provide opportunities in mitigating the global rise in type II diabetes and related non-communicable diseases. However, screening for low glycemic index (GI) in rice breeding programs is not possible due to time and cost constraints. This study evaluated the feasibility of using in vitro cooked grain amylolysis, starch mobilization patterns during seed germination, and variation in starch structure and composition in the mature seed to differentiate patterns of starch digestibility. Mobilization patterns of total starch, resistant starch, amylose and amylopectin chains, and free sugars during seed germination revealed that the process is analogous to digestion in the human gastrointestinal tract. The combination of these biochemical markers can be used as an alternative measure to predict GI. Additionally, transcriptome analysis of stored mRNA transcripts in high and low GI lines detected differences in starch metabolism and confirmed the importance of seed storage pathways in influencing digestibility. Pathway analyses supported by metabolomics data revealed that resistant starch, cell wall non-starch polysaccharides and flavonoids potentially contribute to slower digestibility. These new insights can guide precision breeding programs to produce low GI rice with acceptable cooking quality to help mitigate the burden of diet-associated lifestyle diseases.

  4. Investigation of primary factors affecting the variation of modeled oak pollen concentrations: A case study for Southeast Texas in 2010

    Science.gov (United States)

    Jeon, Wonbae; Choi, Yunsoo; Roy, Anirban; Pan, Shuai; Price, Daniel; Hwang, Mi-Kyoung; Kim, Kyu Rang; Oh, Inbo

    2017-12-01

    Oak pollen concentrations over the Houston-Galveston-Brazoria (HGB) area in southeastern Texas were modeled and evaluated against in-situ data. We modified the Community Multi-scale Air Quality (CMAQ) model to include oak pollen emission, dispersion, and deposition. The Oak Pollen Emission Model (OPEM) calculated gridded oak pollen emissions, which are based on a parameterized equation considering a plant-specific factor (C e ), surface characteristics, and meteorology. The simulation period was chosen to be February 21 to April 30 in the spring of 2010, when the observed monthly mean oak pollen concentrations were the highest in six years (2009-2014). The results indicated C e and meteorology played an important role in the calculation of oak pollen emissions. While C e was critical in determining the magnitude of oak pollen emissions, meteorology determined their variability. In particular, the contribution of the meteorology to the variation in oak pollen emissions increased with the oak pollen emission rate. The evaluation results using in-situ surface data revealed that the model underestimated pollen concentrations and was unable to accurately reproduce the peak pollen episodes. The model error was likely due to uncertainty in climatology-based C e used for the estimation of oak pollen emissions and inaccuracy in the wind fields from the Weather Research and Forecast (WRF) model.

  5. An Investigation of the Effect of Production Rate Variation on Direct Labor Requirements for Missile Production Programs.

    Science.gov (United States)

    1980-06-01

    Model Coefficient Variability Modelo B0 as0 1 A81 a Model Reduced Full (%) Reduced Full (%) 2 1 1775 1882 6 -.20 -.19 -5 -.04 2 1863 1890 1.4...Environment, University of Oregon , Eugene OR, 1976. AD-0926112. 16. Stevens, Captain David Y., and Captain Jimmie Thomerson, USAF. "An Investigation of

  6. Fatores associados à hipotermia durante o transporte intra-hospitalar em pacientes internados em Unidade de Terapia Intensiva Neonatal Pequeño para la edad gestacional: repercusión en las habilidades motoras finas Factors associated with hypothermia during intra-hospital transport in patients assisted in a Neonatal Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Anna Luiza P. Vieira

    2011-03-01

    transporte fueron estudiados por regresión logística. RESULTADOS: De los 1197 transportes realizados en el periodo de estudio, 1191 (99,5% atendieron a los criterios de inclusión. Las enfermedades de base de los 640 niños estudiados (edad gestacional: 35,0±3,8sem; peso al nacer: 2341±888g fueron: malformaciones únicas o múltiples (71%, infecciones (7,7%, hemorragia peri/intraventricular (5,5%, angustia respiratoria (4,0% y otros (11,8%. Los pacientes fueron transportados para realización de cirugías (22,6%, resonancia magnética (10,6%, tomografía (20,9%, exámenes contrastados (18,2% y otros procedimientos (27,7%. La hipotermia ocurrió en 182 (15,3% transportes y se asoció al (OR; IC95%: peso al transporte OBJECTIVE: To determine frequency and factors associated with hypothermia during intra-hospital transports of patients assisted in a neonatal intensive care unit (NICU. METHODS: Cross-sectional study nested in a prospective cohort of infants submitted to intra-hospital transports performed by a trained team from January 1997 to December 2008 at a NICU of a public university hospital. Transports of patients aged more than one year and/or with weight higher than 10kg were excluded. Factors associated with hypothermia during intra-hospital transports were studied by logistic regression analysis. RESULTS: Among the 1,197 transports performed during the studied period, 1,191 (99.5% met the inclusion criteria. The 640 transported infants had mean gestational age of 35.0±3.8 weeks and birth weight of 2341±888g. They presented the following underline diseases: single or multiple malformations (71.0%, infections (7.7%, peri/intraventricular hemorrhage (5.5%, respiratory distress (4.0% and others (11.1%. Patients were transported for surgical procedures (22.6%, magnetic resonance (10.6%, tomography imaging (20.9%, contrasted exams (18.2%, and others (27.7%. Hypothermia occurred in 182 (15.3% transports and was associated with (OR; 95%CI: weight at transport <1000g (3

  7. Investigation of regional geohydrology south of Great Slave Lake, Canada, utilizing natural sulphur and hydrogen isotope variations

    International Nuclear Information System (INIS)

    Weyer, K.U.; Horwood, W.C.; Krouse, H.R.

    1979-01-01

    The well-defined topographic, geological, and orographic setting in the area south of Great Slave Lake, in Canada's North-West Territory (N.W.T.), is favourable for a meaningful investigation of the local and regional groundwater flow sysems in the area of the Mississippi Valley type lead-zinc deposits at Pine Point. Chemical and isotope (delta 34 S, deltaD) investigations have provided supporting evidence for conceptual models of groundwater flow. The range of the deltaD values encountered (-111 to -205 per mille SMOW) indicates that the hydrodynamic systems convey meteoric waters. Differences in deltaD values of water samples were used to elucidate the hydrological relationship between groundwater and a major river in a karst area. The ore bodies at Pine Point are engulfed in a reducing hydrosphere. Sulphur species, derived from gypsum layers by regional groundwater flow, are instrumental in maintaining the reducing conditions. There is evidence that the reduction of sulphate to sulphide is caused by bacteria. Microbiological sulphate reduction, rather than isotopic exchange processes, is also responsible for shifts of measured delta 34 S values in dissolved sulphates. After correction for those shifts, four different sources for dissolved sulphate were identified. In addition to supporting the conceptual model of regional groundwater flow in this area, the isotopic data also help to delineate hydrological features on a more local scale. (author)

  8. Investigation of plasma parameters at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

    Science.gov (United States)

    Wimmer, C.; Fantz, U.; Aza, E.; Jovović, J.; Kraus, W.; Mimo, A.; Schiesko, L.

    2017-08-01

    The Neutral Beam Injection (NBI) system for fusion devices like ITER and, beyond ITER, DEMO requires large scale sources for negative hydrogen ions. BATMAN (Bavarian Test Machine for Negative ions) is a test facility attached with the prototype source for the ITER NBI (1/8 source size of the ITER source), dedicated to physical investigations due to its flexible access for diagnostics and exchange of source components. The required amount of negative ions is produced by surface conversion of hydrogen atoms or ions on caesiated surfaces. Several diagnostic tools (Optical Emission Spectroscopy, Cavity Ring-Down Spectroscopy for H-, Langmuir probes, Tunable Diode Laser Absorption Spectroscopy for Cs) allow the determination of plasma parameters in the ion source. Plasma parameters for two modifications of the standard prototype source have been investigated: Firstly, a second Cs oven has been installed in the bottom part of the back plate in addition to the regularly used oven in the top part of the back plate. Evaporation from the top oven only can lead to a vertically asymmetric Cs distribution in front of the plasma grid. Using both ovens, a symmetric Cs distribution can be reached - however, in most cases no significant change of the extracted ion current has been determined for varying Cs symmetry if the source is well-conditioned. Secondly, BATMAN has been equipped with a much larger, racetrack-shaped RF driver (area of 32×58 cm2) instead of the cylindrical RF driver (diameter of 24.5 cm). The main idea is that one racetrack driver could substitute two cylindrical drivers in larger sources with increased reliability and power efficiency. For the same applied RF power, the electron density is lower in the racetrack driver due to its five times higher volume. The fraction of hydrogen atoms to molecules, however, is at a similar level or even slightly higher, which is a promising result for application in larger sources.

  9. Use of clinical vignette questionnaires to investigate the variation in management of keratoconjunctivitis sicca and acute glaucoma in dogs.

    Science.gov (United States)

    White, Constance N; Downes, Martin J; Jones, Gareth; Wigfall, Corinne; Dean, Rachel S; Brennan, Marnie L

    2018-01-06

    There is little peer-reviewed research assessing therapeutic effectiveness in canine eye disease. Current treatments used in first opinion and ophthalmology referral practices are also somewhat poorly documented. The aim of this study was to investigate the current management of canine keratoconjunctivitis sicca (KCS) and acute primary angle-closure glaucoma (PACG) by veterinary surgeons. Questionnaires using clinical vignettes were administered to a cross section of general practitioners ('GPs') and veterinarians engaged in or training for postgraduate ophthalmology practice ('PGs'). Similar treatment recommendations for KCS (topical cyclosporine, lubricant, antibiotic) were given by both groups of veterinarians with the single exception of increased topical antibiotic use by GPs. Treatment of acute glaucoma diverged between groups: PGs were much more likely to recommend topical prostaglandin analogues and a wider array of both topical and systemic treatments were recommended by both groups. Systemic ocular hypotensive agents were suggested infrequently. Our results suggest that treatments may vary substantially in ocular conditions, particularly in conditions for which neither guidelines nor high-quality evidence exists. This study highlights the need for novel strategies to address evidence gaps in veterinary medicine, as well as for better evaluation and dissemination of current treatment experience. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Serotonin and Dopamine Gene Variation and Theory of Mind Decoding Accuracy in Major Depression: A Preliminary Investigation

    Science.gov (United States)

    Zahavi, Arielle Y.; Sabbagh, Mark A.; Washburn, Dustin; Mazurka, Raegan; Bagby, R. Michael; Strauss, John; Kennedy, James L.; Ravindran, Arun; Harkness, Kate L.

    2016-01-01

    Theory of mind–the ability to decode and reason about others’ mental states–is a universal human skill and forms the basis of social cognition. Theory of mind accuracy is impaired in clinical conditions evidencing social impairment, including major depressive disorder. The current study is a preliminary investigation of the association of polymorphisms of the serotonin transporter (SLC6A4), dopamine transporter (DAT1), dopamine receptor D4 (DRD4), and catechol-O-methyl transferase (COMT) genes with theory of mind decoding in a sample of adults with major depression. Ninety-six young adults (38 depressed, 58 non-depressed) completed the ‘Reading the Mind in the Eyes task’ and a non-mentalistic control task. Genetic associations were only found for the depressed group. Specifically, superior accuracy in decoding mental states of a positive valence was seen in those homozygous for the long allele of the serotonin transporter gene, 9-allele carriers of DAT1, and long-allele carriers of DRD4. In contrast, superior accuracy in decoding mental states of a negative valence was seen in short-allele carriers of the serotonin transporter gene and 10/10 homozygotes of DAT1. Results are discussed in terms of their implications for integrating social cognitive and neurobiological models of etiology in major depression. PMID:26974654

  11. Compositional Variation and Bioactivity of the Leaf Essential Oil of Montanoa guatemalensis from Monteverde, Costa Rica: A Preliminary Investigation

    Directory of Open Access Journals (Sweden)

    Victoria D. Flatt

    2015-11-01

    Full Text Available Background: Montanoa guatemalensis is a small to medium-sized tree in the Asteraceae that grows in Central America from Mexico south through Costa Rica. There have been no previous investigations on the essential oil of this tree. Methods: The leaf essential oils of M. guatemalensis were obtained from different individual trees growing in Monteverde, Costa Rica, in two different years, and were analyzed by gas chromatography—mass spectrometry. Results: The leaf oils from 2008 were rich in sesquiterpenoids, dominated by α-selinene, β-selinene, and cyclocolorenone, with lesser amounts of the monoterpenes α-pinene and limonene. In contrast, the samples from 2009 showed no α- or β-selinene, but large concentrations of trans-muurola-4(14,5-diene, β-cadinene, and cyclocolorenone, along with greater concentrations of α-pinene and limonene. The leaf oils were screened for cytotoxic and antimicrobial activities and did show selective cytotoxic activity on MDA-MB-231 breast tumor cells. Conclusion: M. guatemalensis leaf oil, rich in cyclocolorenone, α-selinene, and β-selinene, showed selective in vitro cytotoxic activity to MDA-MB-231 cells. The plant may be a good source of cyclocolorenone.

  12. Investigation of passenger car using Macpherson strut for suspension system pt.1: Vehicle behaviour variation of time response

    Directory of Open Access Journals (Sweden)

    Ali Tanti

    2017-01-01

    Full Text Available It has been decade, researchers has been conducting researches on the topics concerning vehicle behavior. Suspension system, driving maneuver and road profile are the particular parameters in order to achieve the aim in vehicle behavior understanding. This paper combined these three criteria by means of using a passenger car equipped with MacPherson strut front suspension undergoes different driving behavior. The objective of this paper is to study the effect of passenger car equipped with MacPherson strut front suspension system vehicle behavior based on different driving maneuvers. For this study, Proton Persona Sedan 1.6 Manual Transmission Base Line was used to investigate the MacPherson strut suspension system. Data were collected using DEWESoft Software. As the velocity and direction varies with time, the vehicle response subjected to stationary excitation, while it varies with different velocity and different type of road. Acceleration, deceleration and bumpy test the suspension mechanism support the weight of the vehicle yet to cushion bumps and holes in the road. It can be concluded that the MacPherson strut suspension system has an effect on not only vehicle behavior but also comfort ride. These findings provide the following insights for future research in suspension vibration in order to optimize the performance of the MacPherson strut suspension system.

  13. Investigation into Variation of Endogenous Metabolites in Bone Marrow Cells and Plasma in C3H/He Mice Exposed to Benzene

    Science.gov (United States)

    Sun, Rongli; Zhang, Juan; Yin, Lihong; Pu, Yuepu

    2014-01-01

    Benzene is identified as a carcinogen. Continued exposure of benzene may eventually lead to damage to the bone marrow, accompanied by pancytopenia, aplastic anemia or leukemia. This paper explores the variations of endogenous metabolites to provide possible clues for the molecular mechanism of benzene-induced hematotoxicity. Liquid chromatography coupled with time of flight-mass spectrometry (LC-TOF-MS) and principal component analysis (PCA) was applied to investigate the variation of endogenous metabolites in bone marrow cells and plasma of male C3H/He mice. The mice were injected subcutaneously with benzene (0, 300, 600 mg/day) once daily for seven days. The body weights, relative organ weights, blood parameters and bone marrow smears were also analyzed. The results indicated that benzene caused disturbances in the metabolism of oxidation of fatty acids and essential amino acids (lysine, phenylalanine and tyrosine) in bone marrow cells. Moreover, fatty acid oxidation was also disturbed in plasma and thus might be a common disturbed metabolic pathway induced by benzene in multiple organs. This study aims to investigate the underlying molecular mechanisms involved in benzene hematotoxicity, especially in bone marrow cells. PMID:24658442

  14. Variations in aortic pressure affect the mechanics of the intra-aortic balloon: an in vitro investigation.

    Science.gov (United States)

    Biglino, Giovanni; Kolyva, Christina; Whitehorne, Michael; Pepper, John R; Khir, Ashraf W

    2010-07-01

    This study aims to investigate the mechanics of the intra-aortic balloon (IAB) under different aortic pressure (P(ao)) and inclination (0-75 degrees). Pressure and flow were measured in an artificial aorta during IAB pumping with a frequency of 1:3. Volume displaced toward the "coronary arteries" during inflation (V(prox)) and "intra-aortic" pressure reduction during deflation (P(r)) were derived. IAB duration of inflation and deflation was determined with a high-speed camera visualization. When the aorta was horizontal, P(ao) raised from 45 mm Hg to 115 mm Hg, V(prox) reduced by 18% (25.0 +/- 1.0 mL vs. 30.4 +/- 1.9 mL) and P(r) increased by 117% (106.4 +/- 0.3 mm Hg vs. 48.9 +/- 0.6 mm Hg). When the aorta was inclined, at low P(ao) of 45 mm Hg, V(prox) was reduced by 30% from 0 degrees to 45 degrees (19.8 +/- 2.3 mL vs. 28.3 +/- 1.7 mL) and P(r) was reduced by 66% (16.5 +/- 0.1 mm Hg vs. 48.9 +/- 0.6 mm Hg). However, at high P(ao) of 115 mm Hg, V(prox) remained unchanged with increasing angle (20.0 +/- 1.0 mL) and P(r) was reduced by 24% (80.6 +/- 0.8 mm Hg vs. 106.4 +/- 0.3 mm Hg). Increasing P(ao) increased duration of inflation. At low P(ao), increasing angle resulted in increasing duration of inflation, but at high P(ao), increasing angle had the opposite effect. Duration of deflation generally decreased with P(ao) and increased with increasing angle. The IAB pump is affected by both P(ao) and angle, indicating that non-normotensive patients or patients in the semi-recumbent position might not receive the full benefits of IAB counterpulsation.

  15. Systematic investigation of contribution of genetic variation in the HLA-DP region to cervical cancer susceptibility.

    Science.gov (United States)

    Chen, Dan; Gyllensten, Ulf

    2014-08-01

    Compared with the other human leukocyte antigen (HLA) genes, few studies have evaluated the role of HLA-DP genes in cervical cancer pathogenesis. A recent genome-wide association study (GWAS) in the Swedish population has identified a susceptibility locus for cervical cancer within the HLA-DP region. To further study this locus, we imputed classic HLA alleles using single-nucleotide polymorphism (SNP) data and analysed 449 genotyped and 3066 imputed SNPs in 1034 cervical cancer patients and 3948 controls. We confirmed that the strongest signal came from a SNP located at HLA-DPB2 [rs3117027, odds ratio (OR) = 1.29, 95% confidence interval (CI) = 1.16-1.43, P = 1.9 × 10(-6) for A allele] and that this effect is not driven by associations with classic HLA alleles. In silico analysis further revealed that this SNP is highly correlated with rs3129294 (D' = 1, r(2) = 0.95 in controls), which may have a putative regulatory function. We also identified an independent association at DPB1*0402, which conferred decreased risk of cervical cancer (OR = 0.75, 95% CI = 0.63-0.89, P = 7.0 × 10(-4)) and is independent of previously described associations with HLA-B*0702, DRB1*1501-DQB1*0602, and DRB1*1301-DQA1*0103-DQB1*0603. No association was found with the two SNPs (rs4282438 or rs9277952) that were recently identified within the HLA-DP region in a cervical cancer GWAS in the Chinese population. Our study provides the first systematic investigation of the association of genetic variants in the HLA-DP region with cervical cancer susceptibility and provides further insight into the contribution of polymorphisms in the HLA-DP region to risk of cervical cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Investigation of variations in the acrylamide and N(ε) -(carboxymethyl) lysine contents in cookies during baking.

    Science.gov (United States)

    Cheng, Lu; Jin, Cheng; Zhang, Ying

    2014-05-01

    Baking processing is indispensable to determine special sensory prosperities of cookies and induces the formation of some beneficial components such as antioxidants. However, the formation of some Maillard reaction-derived chemical hazards, such as acrylamide (AA) and N(ε) -(carboxymethyl) lysine (CML) in cookies is also a significant consequence of baking processing from a food safety standpoint. This study investigated the effects of baking conditions on the formation of AA and CML, as well as the antioxidant activity (AOA) of cookies. Cookies were baked at various baking temperatures (155 to 230 °C) and times (1.5 to 31 min). AA and CML contents were determined by ultra-performance liquid chromatography-tandem mass spectrometry, respectively. The highest level of AA was obtained in the cookies baked at 155 °C/21 min and 205 °C/11 min (328.93 ± 3.10 μg/kg and 329.29 ± 5.29 μg/kg), while the highest level of CML was obtained in the cookies baked at 230 °C/1.5 min (118.05 ± 0.21 mg/kg). AA was prone to form at relatively low temperature range (155 to 205 °C), however, CML at relatively high temperature range (205 to 230 °C). The CML content was much higher than the AA content in the same set of cookies, by about 2 to 3 orders of magnitude. The AOA of cookies increased at more severe baking conditions. According to the AA and CML content, AOA and sensory properties of cookies, the temperature-time regime of 180 °C/16 min might be a compromised selection. However, only optimizing the baking condition was not enough for manufacture of high-quality cookies. Cookies, a kind of widely consumed bakery products in the world, contain some potentially harmful compounds, like acrylamide (AA) and N(ε) -(carboxymethyl) lysine (CML). AA in cookies has led to public health concern and several research efforts. But CML, another Maillard reaction-derived chemical hazard, has been neglected so far, even though its content is much higher than that of AA in cookies. The

  17. An investigation of the inter-clonal variation of the interactive effects of cadmium and Microcystis aeruginosa on the reproductive performance of Daphnia magna.

    Science.gov (United States)

    De Coninck, Dieter I M; Janssen, Colin R; De Schamphelaere, Karel A C

    2013-09-15

    Interactive effects between chemical and natural stressors as well as genetically determined variation in stress tolerance among individuals may complicate risk assessment and management of chemical pollutants in natural ecosystems. Although genetic variation in tolerance to single stressors has been described extensively, genetic variation in interactive effects between two stressors has only rarely been investigated. Here, we examined the interactive effects between a chemical stressor (Cd) and a natural stressor (the cyanobacteria Microcystis aeruginosa) on the reproduction of Daphnia magna in 20 genetically different clones using a full-factorial experimental design and with the independent action model of joint stressor action as the reference theoretical framework. Across all clones, the reduction of 21-day reproduction compared to the control treatment (no Cd, no M. aeruginosa) ranged from -10% to 98% following Cd exposure alone, from 44% to 89% for Microcystis exposure alone, and from 61% to 98% after exposure to Cd+Microcystis combined. Three-way ANOVA on log-transformed reproduction data of all clones together did not detect a statistically significant Cd×Microcystis interaction term (F-test, p=0.11), meaning that on average both stressors do not interact in inhibiting reproductive performance of D. magna. This finding contrasted expectations based on some known shared mechanisms of toxicity of Cd and Microcystis and therefore cautions against making predictions of interactive chemical+natural stressor effects from incomplete knowledge on affected biological processes and pathways. Further, still based on three-way ANOVA, we did not find statistically significant clone×Cd×Microcystis interaction when data for all clones were analyzed together (F-test, p=0.07), suggesting no inter-clonal variation of the interactive effect between Cd and Microcystis. However, when the same data were quantitatively analyzed on a clone-by-clone scale, we found a

  18. An investigation of the inter-clonal variation of the interactive effects of cadmium and Microcystis aeruginosa on the reproductive performance of Daphnia magna

    International Nuclear Information System (INIS)

    De Coninck, Dieter I.M.; Janssen, Colin R.; De Schamphelaere, Karel A.C.

    2013-01-01

    Highlights: •Interaction of a metal and cyanobacterium in 20 genetically distinct waterflea clones. •All observed effects were non-interactive. •This contrasted expectations based on shared modes of toxic action. -- Abstract: Interactive effects between chemical and natural stressors as well as genetically determined variation in stress tolerance among individuals may complicate risk assessment and management of chemical pollutants in natural ecosystems. Although genetic variation in tolerance to single stressors has been described extensively, genetic variation in interactive effects between two stressors has only rarely been investigated. Here, we examined the interactive effects between a chemical stressor (Cd) and a natural stressor (the cyanobacteria Microcystis aeruginosa) on the reproduction of Daphnia magna in 20 genetically different clones using a full-factorial experimental design and with the independent action model of joint stressor action as the reference theoretical framework. Across all clones, the reduction of 21-day reproduction compared to the control treatment (no Cd, no M. aeruginosa) ranged from −10% to 98% following Cd exposure alone, from 44% to 89% for Microcystis exposure alone, and from 61% to 98% after exposure to Cd + Microcystis combined. Three-way ANOVA on log-transformed reproduction data of all clones together did not detect a statistically significant Cd × Microcystis interaction term (F-test, p = 0.11), meaning that on average both stressors do not interact in inhibiting reproductive performance of D. magna. This finding contrasted expectations based on some known shared mechanisms of toxicity of Cd and Microcystis and therefore cautions against making predictions of interactive chemical + natural stressor effects from incomplete knowledge on affected biological processes and pathways. Further, still based on three-way ANOVA, we did not find statistically significant clone × Cd × Microcystis interaction when data for

  19. An investigation of the inter-clonal variation of the interactive effects of cadmium and Microcystis aeruginosa on the reproductive performance of Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    De Coninck, Dieter I.M., E-mail: Dieter.DeConinck@UGent.be; Janssen, Colin R.; De Schamphelaere, Karel A.C.

    2013-09-15

    Highlights: •Interaction of a metal and cyanobacterium in 20 genetically distinct waterflea clones. •All observed effects were non-interactive. •This contrasted expectations based on shared modes of toxic action. -- Abstract: Interactive effects between chemical and natural stressors as well as genetically determined variation in stress tolerance among individuals may complicate risk assessment and management of chemical pollutants in natural ecosystems. Although genetic variation in tolerance to single stressors has been described extensively, genetic variation in interactive effects between two stressors has only rarely been investigated. Here, we examined the interactive effects between a chemical stressor (Cd) and a natural stressor (the cyanobacteria Microcystis aeruginosa) on the reproduction of Daphnia magna in 20 genetically different clones using a full-factorial experimental design and with the independent action model of joint stressor action as the reference theoretical framework. Across all clones, the reduction of 21-day reproduction compared to the control treatment (no Cd, no M. aeruginosa) ranged from −10% to 98% following Cd exposure alone, from 44% to 89% for Microcystis exposure alone, and from 61% to 98% after exposure to Cd + Microcystis combined. Three-way ANOVA on log-transformed reproduction data of all clones together did not detect a statistically significant Cd × Microcystis interaction term (F-test, p = 0.11), meaning that on average both stressors do not interact in inhibiting reproductive performance of D. magna. This finding contrasted expectations based on some known shared mechanisms of toxicity of Cd and Microcystis and therefore cautions against making predictions of interactive chemical + natural stressor effects from incomplete knowledge on affected biological processes and pathways. Further, still based on three-way ANOVA, we did not find statistically significant clone × Cd × Microcystis interaction when data for

  20. Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in "Brassica rapa" Fast Plants

    Science.gov (United States)

    Batzli, Janet M.; Smith, Amber R.; Williams, Paul H.; McGee, Seth A.; Dosa, Katalin; Pfammatter, Jesse

    2014-01-01

    Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question "What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev)," we developed a 4-wk unit for an inquiry-based laboratory…

  1. Maintenance of genetic variation in human personality: Testing evolutionary models by estimating heritability due to common causal variants and investigating the effect of distant inbreeding

    NARCIS (Netherlands)

    Verweij, K.J.H.; Yang, J.; Lahti, J.; Veijola, J.; Hintsanen, M.; Pulkki-Raback, L.; Heinonen, K.; Pouta, A.; Pesonen, A.K.; Widen, E.; Taanila, A.; Isohanni, M.; Miettunen, J.; Palotie, A.; Penke, L.; Service, S.K.; Heath, A.C.; Montgomery, G.W.; Raitakari, O.; Kahonen, M.; Viikari, J.; Raikkonen, K.; Eriksson, J.G.; Keltikangas-Jarvinen, L.; Lehtimäki, T.; Martin, N.G.; Jarvelin, M.R.; Visscher, P.M.; Keller, M.C.; Zietsch, B.P.

    2012-01-01

    Personality traits are basic dimensions of behavioral variation, and twin, family, and adoption studies show that around 30% of the between-individual variation is due to genetic variation. There is rapidly growing interest in understanding the evolutionary basis of this genetic variation. Several

  2. Maintenance of genetic variation in human personality: Testing evolutionary models by estimating heritability due to common causal variants and investigating the effect of distant inbreeding.

    NARCIS (Netherlands)

    Verweij, K.J.H.; Yang, J.; Lahti, J.; Veijola, J.; Hintsanen, M.; Pulkki-Råback, L.; Heinonen, K.; Pouta, A.; Pesonen, A.K.; Widen, E.; Taanila, A.; Isohanni, M.; Miettunen, J.; Palotie, A.; Penke, L; Service, S.K.; Heath, A.C.; Montgomery, G.W.; Raitakari, O.; Kähönen, M.; Viikari, J.; Räikkönen, K.; Eriksson, J.G.; Keltikangas-Järvinen, L.; Lehtimäki, T.; Martin, N.G.; Järvelin, M.R.; Visscher, P.M.; Keller, M.C.; Zietsch, B.P.

    2012-01-01

    Personality traits are basic dimensions of behavioral variation, and twin, family, and adoption studies show that around 30% of the between-individual variation is due to genetic variation. There is rapidly growing interest in understanding the evolutionary basis of this genetic variation. Several

  3. Investigation of 2 models to set and evaluate quality targets for hb a1c: biological variation and sigma-metrics.

    Science.gov (United States)

    Weykamp, Cas; John, Garry; Gillery, Philippe; English, Emma; Ji, Linong; Lenters-Westra, Erna; Little, Randie R; Roglic, Gojka; Sacks, David B; Takei, Izumi

    2015-05-01

    A major objective of the IFCC Task Force on Implementation of HbA1c Standardization is to develop a model to define quality targets for glycated hemoglobin (Hb A1c). Two generic models, biological variation and sigma-metrics, are investigated. We selected variables in the models for Hb A1c and used data of external quality assurance/proficiency testing programs to evaluate the suitability of the models to set and evaluate quality targets within and between laboratories. In the biological variation model, 48% of individual laboratories and none of the 26 instrument groups met the minimum performance criterion. In the sigma-metrics model, with a total allowable error (TAE) set at 5 mmol/mol (0.46% NGSP), 77% of the individual laboratories and 12 of 26 instrument groups met the 2σ criterion. The biological variation and sigma-metrics models were demonstrated to be suitable for setting and evaluating quality targets within and between laboratories. The sigma-metrics model is more flexible, as both the TAE and the risk of failure can be adjusted to the situation-for example, requirements related to diagnosis/monitoring or international authorities. With the aim of reaching (inter)national consensus on advice regarding quality targets for Hb A1c, the Task Force suggests the sigma-metrics model as the model of choice, with default values of 5 mmol/mol (0.46%) for TAE and risk levels of 2σ and 4σ for routine laboratories and laboratories performing clinical trials, respectively. These goals should serve as a starting point for discussion with international stakeholders in the field of diabetes. © 2015 American Association for Clinical Chemistry.

  4. Investigation of temperature dependent threshold voltage variation of Gd2O3/AlGaN/GaN metal-oxide-semiconductor heterostructure

    Directory of Open Access Journals (Sweden)

    Atanu Das

    2012-09-01

    Full Text Available Temperature dependent threshold voltage (Vth variation of GaN/AlGaN/Gd2O3/Ni-Au structure is investigated by capacitance-voltage measurement with temperature varying from 25°C to 150°C. The Vth of the Schottky device without oxide layer is slightly changed with respect to temperature. However, variation of Vth is observed for both as-deposited and annealed device owing to electron capture by the interface traps or bulk traps. The Vth shifts of 0.4V and 3.2V are obtained for as-deposited and annealed device respectively. For annealed device, electron capture process is not only restricted in the interface region but also extended into the crystalline Gd2O3 layer through Frenkel-Poole emission and hooping conduction, resulting in a larger Vth shift. The calculated trap density for as-deposited and annealed device is 3.28×1011∼1.12×1011 eV−1cm−2 and 1.74×1012∼7.33×1011 eV−1cm−2 respectively in measured temperature range. These results indicate that elevated temperature measurement is necessary to characterize GaN/AlGaN heterostructure based devices with oxide as gate dielectric.

  5. Investigating the genomic basis of discrete phenotypes using a Pool-Seq-only approach: New insights into the genetics underlying colour variation in diverse taxa.

    Science.gov (United States)

    Neethiraj, Ramprasad; Hornett, Emily A; Hill, Jason A; Wheat, Christopher W

    2017-10-01

    While large-scale genomic approaches are increasingly revealing the genetic basis of polymorphic phenotypes such as colour morphs, such approaches are almost exclusively conducted in species with high-quality genomes and annotations. Here, we use Pool-Seq data for both genome assembly and SNP frequency estimation, followed by scanning for F ST outliers to identify divergent genomic regions. Using paired-end, short-read sequencing data from two groups of individuals expressing divergent phenotypes, we generate a de novo rough-draft genome, identify SNPs and calculate genomewide F ST differences between phenotypic groups. As genomes generated by Pool-Seq data are highly fragmented, we also present an approach for super-scaffolding contigs using existing protein-coding data sets. Using this approach, we reanalysed genomic data from two recent studies of birds and butterflies investigating colour pattern variation and replicated their core findings, demonstrating the accuracy and power of a Pool-Seq-only approach. Additionally, we discovered new regions of high divergence and new annotations that together suggest novel parallels between birds and butterflies in the origins of their colour pattern variation. © 2017 John Wiley & Sons Ltd.

  6. Combining Unsteady Blade Pressure Measurements and a Free-Wake Vortex Model to Investigate the Cycle-to-Cycle Variations in Wind Turbine Aerodynamic Blade Loads in Yaw

    Directory of Open Access Journals (Sweden)

    Moutaz Elgammi

    2016-06-01

    Full Text Available Prediction of the unsteady aerodynamic flow phenomenon on wind turbines is challenging and still subject to considerable uncertainty. Under yawed rotor conditions, the wind turbine blades are subjected to unsteady flow conditions as a result of the blade advancing and retreating effect and the development of a skewed vortical wake created downstream of the rotor plane. Blade surface pressure measurements conducted on the NREL Phase VI rotor in yawed conditions have shown that dynamic stall causes the wind turbine blades to experience significant cycle-to-cycle variations in aerodynamic loading. These effects were observed even though the rotor was subjected to a fixed speed and a uniform and steady wind flow. This phenomenon is not normally predicted by existing dynamic stall models integrated in wind turbine design codes. This paper couples blade pressure measurements from the NREL Phase VI rotor to a free-wake vortex model to derive the angle of attack time series at the different blade sections over multiple rotor rotations and three different yaw angles. Through the adopted approach it was possible to investigate how the rotor self-induced aerodynamic load fluctuations influence the unsteady variations in the blade angles of attack and induced velocities. The hysteresis loops for the normal and tangential load coefficients plotted against the angle of attack were plotted over multiple rotor revolutions. Although cycle-to-cycle variations in the angles of attack at the different blade radial locations and azimuth positions are found to be relatively small, the corresponding variations in the normal and tangential load coefficients may be significant. Following a statistical analysis, it was concluded that the load coefficients follow a normal distribution at the majority of blade azimuth angles and radial locations. The results of this study provide further insight on how existing engineering models for dynamic stall may be improved through

  7. Investigation of the variations in the crystallization front shape during growth of gadolinium gallium and terbium gallium crystals by the Czochralski method

    International Nuclear Information System (INIS)

    Budenkova, O. N.; Vasiliev, M. G.; Yuferev, V. S.; Ivanov, I. A.; Bul'kanov, A. M.; Kalaev, V. V.

    2008-01-01

    Numerical investigation of the variations in the crystallization front shape during growth of gadolinium gallium and terbium gallium garnet crystals in the same thermal zone and comparison of the obtained results with the experimental data have been performed. It is shown that the difference in the behavior of the crystallization front during growth of the crystals is related to their different transparency in the IR region. In gadolinium gallium garnet crystals, which are transparent to thermal radiation, a crystallization front, strongly convex toward the melt, is formed in the growth stage, which extremely rapidly melts under forced convection. Numerical analysis of this process has been performed within the quasistationary and nonstationary models. At the same time, in terbium gallium garnet crystals, which are characterized by strong absorption of thermal radiation, the phase boundary shape changes fairly smoothly and with a small amplitude. In this case, as the crystal is pulled, the crystallization front tends to become convex toward the crystal bulk.

  8. Using large scale surveys to investigate seasonal variations in seabird distribution and abundance. Part II: The Bay of Biscay and the English Channel

    Science.gov (United States)

    Pettex, Emeline; Laran, Sophie; Authier, Matthieu; Blanck, Aurélie; Dorémus, Ghislain; Falchetto, Hélène; Lambert, Charlotte; Monestiez, Pascal; Stéfan, Eric; Van Canneyt, Olivier; Ridoux, Vincent

    2017-07-01

    Seabird distributions and the associated seasonal variations remain challenging to investigate, especially in oceanic areas. Recent advances in telemetry have provided considerable information on seabird ecology, but still exclude small species, non-breeding birds and individuals from inaccessible colonies from any scientific survey. To overcome this issue and investigate seabird distribution and abundance in the eastern North Atlantic (ENA), large-scale aerial surveys were conducted in winter 2011-12 and summer 2012 over a 375,000 km2 area encompassing the English Channel (EC) and the Bay of Biscay (BoB). Seabird sightings, from 15 taxonomic groups, added up to 17,506 and 8263 sightings in winter and summer respectively, along 66,307 km. Using geostatistical methods, density maps were provided for both seasons. Abundance was estimated by strip transect sampling. Most taxa showed marked seasonal variations in their density and distribution. The highest densities were recorded during winter for most groups except shearwaters, storm-petrels, terns and large-sized gulls. Subsequently, the abundance in winter nearly reached one million individuals and was 2.5 times larger than in summer. The continental shelf and the slope in the BoB and the EC were identified as key areas for seabird conservation, especially during winter, as birds from northern Europe migrate southward after breeding. This large-scale study provided a synoptic view of the seabird community in the ENA, over two contrasting seasons. Our results highlight that oceanic areas harbour an abundant avifauna. Since most of the existing marine protected areas are restricted to the coastal fringe, the importance of oceanic areas in winter should be considered in future conservation plans. Our work will provide a baseline for the monitoring of seabird distribution at sea, and could inform the EU Marine Strategy Framework Directive.

  9. Investigating the Influence of Box-Constraints on the Solution of a Total Variation Model via an Efficient Primal-Dual Method

    Directory of Open Access Journals (Sweden)

    Andreas Langer

    2018-01-01

    Full Text Available In this paper, we investigate the usefulness of adding a box-constraint to the minimization of functionals consisting of a data-fidelity term and a total variation regularization term. In particular, we show that in certain applications an additional box-constraint does not effect the solution at all, i.e., the solution is the same whether a box-constraint is used or not. On the contrary, i.e., for applications where a box-constraint may have influence on the solution, we investigate how much it effects the quality of the restoration, especially when the regularization parameter, which weights the importance of the data term and the regularizer, is chosen suitable. In particular, for such applications, we consider the case of a squared L 2 data-fidelity term. For computing a minimizer of the respective box-constrained optimization problems a primal-dual semi-smooth Newton method is presented, which guarantees superlinear convergence.

  10. Red shift, blue shift: investigating Doppler shifts, blubber thickness, and migration as explanations of seasonal variation in the tonality of Antarctic blue whale song.

    Directory of Open Access Journals (Sweden)

    Brian S Miller

    Full Text Available The song of Antarctic blue whales (Balaenoptera musculus intermedia comprises repeated, stereotyped, low-frequency calls. Measurements of these calls from recordings spanning many years have revealed a long-term linear decline as well as an intra-annual pattern in tonal frequency. While a number of hypotheses for this long-term decline have been investigated, including changes in population structure, changes in the physical environment, and changes in the behaviour of the whales, there have been relatively few attempts to explain the intra-annual pattern. An additional hypothesis that has not yet been investigated is that differences in the observed frequency from each call are due to the Doppler effect. The assumptions and implications of the Doppler effect on whale song are investigated using 1 vessel-based acoustic recordings of Antarctic blue whales with simultaneous observation of whale movement and 2 long-term acoustic recordings from both the subtropics and Antarctic. Results from vessel-based recordings of Antarctic blue whales indicate that variation in peak-frequency between calls produced by an individual whale was greater than would be expected by the movement of the whale alone. Furthermore, analysis of intra-annual frequency shift at Antarctic recording stations indicates that the Doppler effect is unlikely to fully explain the observations of intra-annual pattern in the frequency of Antarctic blue whale song. However, data do show cyclical changes in frequency in conjunction with season, thus suggesting that there might be a relationship among tonal frequency, body condition, and migration to and from Antarctic feeding grounds.

  11. Maintenance of genetic variation in human personality: testing evolutionary models by estimating heritability due to common causal variants and investigating the effect of distant inbreeding.

    Science.gov (United States)

    Verweij, Karin J H; Yang, Jian; Lahti, Jari; Veijola, Juha; Hintsanen, Mirka; Pulkki-Råback, Laura; Heinonen, Kati; Pouta, Anneli; Pesonen, Anu-Katriina; Widen, Elisabeth; Taanila, Anja; Isohanni, Matti; Miettunen, Jouko; Palotie, Aarno; Penke, Lars; Service, Susan K; Heath, Andrew C; Montgomery, Grant W; Raitakari, Olli; Kähönen, Mika; Viikari, Jorma; Räikkönen, Katri; Eriksson, Johan G; Keltikangas-Järvinen, Liisa; Lehtimäki, Terho; Martin, Nicholas G; Järvelin, Marjo-Riitta; Visscher, Peter M; Keller, Matthew C; Zietsch, Brendan P

    2012-10-01

    Personality traits are basic dimensions of behavioral variation, and twin, family, and adoption studies show that around 30% of the between-individual variation is due to genetic variation. There is rapidly growing interest in understanding the evolutionary basis of this genetic variation. Several evolutionary mechanisms could explain how genetic variation is maintained in traits, and each of these makes predictions in terms of the relative contribution of rare and common genetic variants to personality variation, the magnitude of nonadditive genetic influences, and whether personality is affected by inbreeding. Using genome-wide single nucleotide polymorphism (SNP) data from > 8000 individuals, we estimated that little variation in the Cloninger personality dimensions (7.2% on average) is due to the combined effect of common, additive genetic variants across the genome, suggesting that most heritable variation in personality is due to rare variant effects and/or a combination of dominance and epistasis. Furthermore, higher levels of inbreeding were associated with less socially desirable personality trait levels in three of the four personality dimensions. These findings are consistent with genetic variation in personality traits having been maintained by mutation-selection balance. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  12. Investigation of the variation of the specific heat capacity of local soil samples from the Niger delta, Nigeria with moisture content

    International Nuclear Information System (INIS)

    Ofoegbu, C.O.; Adjepong, S.K.

    1987-11-01

    Results of an investigation of the variation, with moisture content, of the specific heat capacity of samples of three texturally different types of soil (clayey, sandy and sandy loam) obtained from the Niger delta area of Nigeria, are presented. The results show that the specific heat capacities of the soils studied, increase with moisture content. This increase is found to be linear for the entire range of moisture contents considered (0-25%), in the case of the sandy loam soil while for the clayey and sandy soils the specific heat capacity is found to increase linearly with moisture content up to about 15% after which the increase becomes parabolic. The rate of increase of specific heat capacity with moisture content appears to be highest in the clayey soil and lowest in the sandy soil. It is thought that the differences in the rates of increase of specific heat capacity with moisture content, observed for the soils, reflect the soils' water-retention capacities. (author) 3 refs, 5 figs

  13. Variations of water uptake, lipid consumption, and dynamics during the germination of Sesamum indicum seed: a nuclear magnetic resonance spectroscopic investigation.

    Science.gov (United States)

    Sarkar, Bimal Kumar; Yang, Wei-Yuan; Wu, Zhen; Tang, Huiru; Ding, Shangwu

    2009-09-23

    Germination in sesame seeds (Sesamum indicum L.) in water and in indole-3-acetic acid (IAA) solution is investigated with magic-angle-spinning (MAS) solid state nuclear magnetic resonance (NMR) spectroscopy, supplemented by liquid state NMR spectroscopy. The spectra show good resolution and can be assigned with sufficient confidence. The characteristic spectral peaks and relaxation rates were monitored during the entire course of germination for better understanding of the biophysical and biochemical mechanisms involved in the triphasic water uptake of the seed. A highly positive correlation is found between water uptake and lipid consumption during germination. No significant variation is observed in the relaxation times for the lipid protons during the first two stages of triphasic water uptake, while evident differences are observed for water proton relaxation rates in all stages. Although the total amount of water uptake is largely not changed as a result of IAA, the addition of IAA in seed-germination medium has shown some prominent effects on the germination process, e.g, it suppresses lipid consumption and water mobility, and it reduces the longitudinal and transverse relaxation times of lipid protons and causes a more scattered range for these parameters.

  14. Black-White Disparity in Young Adults' Disease Risk: An Investigation of Variation in the Vulnerability of Black Young Adults to Early and Later Adversity.

    Science.gov (United States)

    Wickrama, Kandauda A S; Bae, Dayoung; O'Neal, Catherine Walker

    2016-08-01

    Socioeconomic adversity in early years and young adulthood are risk factors for poor health in young adulthood. Population differences in exposure to stressful socioeconomic conditions partly explain the higher prevalence of disease among black young adults. Another plausible mechanism is that blacks are differentially vulnerable to socioeconomic adversity (differential vulnerability hypothesis), which has not been adequately investigated in previous research. The present study investigated variation in the vulnerability of black young adults leading to cardiometabolic (CM) disease risk. We used a nationally representative sample of 8,824 adolescents who participated in the Add Health study. Early and later adversity was measured using a cumulative index of social and material adversity in adolescence and young adulthood. CM disease risk was assessed using nine biomarkers. Path analysis within a structural equation modeling framework was used. The findings indicated that both early and later socioeconomic adversity act as stressors with independent additive influences on young adults' CM disease risk, consistent with the differential exposure hypothesis. Moreover, the results showed that black youth are less vulnerable to early socioeconomic adversity than whites, but they are more vulnerable to later adversity. The findings provide support for the unique and additive influences of early and later socioeconomic adversity on CM disease risk contributing to the black-white health disparity in young adulthood. The results also suggest that vulnerability to adversity varies depending on the life stage, which highlights the need for life-stage specific interventions to mitigate the existing black-white disparity in young adults' physical health. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  15. Variation in risk indicators of cardiovascular disease during the menstrual cycle: an investigation of within-subject variations in glutathione peroxidase, haemostatic variables, lipids and lipoproteins in healthy young women

    DEFF Research Database (Denmark)

    Larsen, L F; Andersen, H R; Hansen, A B

    1996-01-01

    Variations in erythrocyte glutathione peroxidase activity, serum concentrations of lipids and lipoproteins and in blood coagulation and fibrinolysis during the menstrual cycle were studied in healthy young women. Blood samples were drawn twice a week for 9 weeks. A group of males was used...

  16. Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in Brassica rapa Fast Plants

    Science.gov (United States)

    Smith, Amber R.; Williams, Paul H.; McGee, Seth A.; Dósa, Katalin; Pfammatter, Jesse

    2014-01-01

    Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics. PMID:25185225

  17. Variation in risk indicators of cardiovascular disease during the menstrual cycle: an investigation of within-subject variations in glutathione peroxidase, haemostatic variables, lipids and lipoproteins in healthy young women

    DEFF Research Database (Denmark)

    Larsen, L F; Andersen, H R; Hansen, A B

    1996-01-01

    Variations in erythrocyte glutathione peroxidase activity, serum concentrations of lipids and lipoproteins and in blood coagulation and fibrinolysis during the menstrual cycle were studied in healthy young women. Blood samples were drawn twice a week for 9 weeks. A group of males was used...... for estimation of the influence on the results of factors which were not related to the menstrual cycle. Variations during the menstrual cycle were demonstrated in several of the factors analysed. The activity of glutathione peroxidase was lowest at ovulation. The clotting activity of factor II+ VII...... the menstrual cycle. The serum concentrations of cholesterol and LDL cholesterol were significantly higher at the start of the menstrual cycle (days 3-8) than later in the cycle (days 19-24). The concentration of HDL cholesterol was lowest in the late luteal phase (days 23-28)....

  18. Hospital staffing and local pay: an investigation into the impact of local variations in the competitiveness of nurses' pay on the staffing of hospitals in France.

    Science.gov (United States)

    Combes, Jean-Baptiste; Delattre, Eric; Elliott, Bob; Skåtun, Diane

    2015-09-01

    Spatial wage theory suggests that employers in different regions may offer different pay rates to reflect local amenities and cost of living. Higher wages may be required to compensate for a less pleasant environment or a higher cost of living. If wages in a competing sector within an area are less flexible and therefore less competitive this may lead to an inability to employ staff. This paper considers the market for nursing staff in France where there is general regulation of wages and public hospitals compete for staff with the private hospital and non-hospital sectors. We consider two types of nursing staff, registered and assistant nurses and first establish the degree of spatial variation in the competitiveness of pay of nurses in public hospitals. We then consider whether these spatial variations are associated with variation in the employment of nursing staff. We find that despite regulation of pay in the public and private sector, there are substantial local variations in the competitiveness of nurses' pay. We find evidence that the spatial variations in the competitiveness of pay are associated with relative numbers of assistant nurses but not registered nurses. While we find the influence of the competitiveness of pay is small, it suggests that nonpay conditions may be an important factor in adjusting the labour market as might be expected in such a regulated market.

  19. Investigation of O+ and N+ ion concentration variations, dynamics of the ionosphere and energetic electron fluxes in the outer Earth ionosphere on the ''Meteor'' satellite

    International Nuclear Information System (INIS)

    Ivanov, G.V.; Perkov, I.A.; Pogulyaevskij, L.I.; Romanovskij, Yu.A.; Rylov, Yu.P.; Yaichnikov, A.P.

    1980-01-01

    Using a mass-spectrometric installation from the ''Meteor'' satellite carried out are the measurements of O + and N + ion concentrations, large-scale drifts of O + ions, as well as electron fluxes with the energy of E>350 eV at the altitute approximately 90O km in the outer Earth ionosphere while the minimum of the 21 nd cycle of solar activity. The technique for measurement of ion and electron fluxes drifts are described. In particular, obtained are the data on season and day variations of ions, found is the asymmetry of hemispheres according to amplitudes of day and season variations of n[O + ] concentrations. For example, day amplitude of n[O + ] variation in the southern hemisphere in the vicinity of summer solstice constitutes a factor of 3-4, mainly at the expense of anomalously high ion concentrations during the night

  20. Intron sequence of the taurocyamine kinase gene as a marker to investigate genetic variation of Paragonimus species in Japan and the origins of triploidy in P. westermani.

    Science.gov (United States)

    Saijuntha, Weerachai; Tantrawatpan, Chairat; Jarilla, Blanca R; Agatsuma, Takeshi; Andrews, Ross H; Petney, Trevor N

    2016-01-01

    Paragonimiasis is a foodborne parasitic infection caused by lung flukes of the genus Paragonimus. Several species of Paragonimus are endemic in Japan: P. westermani (diploid and triploid) P. miyazakii, P. ohirai and P. iloktsuenensis. The taxonomic status and genetic variability of these lung flukes remains poorly understood. The second intron of domain 1 of the taurocyamine kinase gene (TKD1int2) region was used to explore genetic variation and differentiation of diploid and triploid P. westermani, as well as P. miyazakii, P. ohirai and P. iloktsuenensis originating from Japan. We found high levels of intraspecific variation in P. westermani, but only low levels of variation within the other species studied. Haplotype network and phylogenetic tree analyses demonstrated the sister-group relationship of P. ohirai and P. iloktsuenensis and the phylogenetically distant relationship of P. westermani with the other species. All individuals except for triploid P. westermani were homozygous. Each triploid contained at least one allele similar to that seen in most diploids from Chiba and one allele resembling that seen in diploids from Oita. One triploid contained three different sequences. Our findings suggested that the TKD1int2 region is a suitable marker for use in studying the genetic variation and phylogenetics of Paragonimus species, as well as providing clues to the origins of triploidy in P. westermani. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Dead wood dependent organisms in one of the oldest protected forests of Europe: Investigating the contrasting effects of within-stand variation in a highly diversified environment

    Czech Academy of Sciences Publication Activity Database

    Horák, J.; Kout, J.; Vodka, Štěpán; Donato, D. C.

    2016-01-01

    Roč. 363, MAR 1 (2016), s. 229-236 ISSN 0378-1127 Institutional support: RVO:60077344 Keywords : biodiversity * gaps * microenvironment variation Subject RIV: EH - Ecology, Behaviour Impact factor: 3.064, year: 2016 http://www.sciencedirect.com/science/article/pii/S0378112715007744

  2. The Variational Fair Autoencoder

    NARCIS (Netherlands)

    Louizos, C.; Swersky, K.; Li, Y.; Welling, M.; Zemel, R.

    2016-01-01

    We investigate the problem of learning representations that are invariant to certain nuisance or sensitive factors of variation in the data while retaining as much of the remaining information as possible. Our model is based on a variational autoencoding architecture with priors that encourage

  3. Near IR overtone spectral investigations of cyclohexanol using local mode model--evidence for variation of anharmonicity with concentration due to hydrogen bonding.

    Science.gov (United States)

    John, Usha; Nair, K P R

    2005-09-01

    The near infrared vibrational overtone absorption spectrum of liquid phase cyclohexanol in carbon tetrachloride in different concentrations are examined in the region Deltav=2, 3 and 4. The free and bonded OH local mode mechanical frequency values and anharmonicity values obtained from fitting the overtones are analysed. The observation supports the conclusions drawn from earlier experimental studies on anharmonicity variation of OH-stretching vibrations of alcohols due to intermolecular hydrogen bonding. Our observation is also in agreement with the ab initio calculations on water dimer and trimer. Mechanical anharmonicity of bonded OH-stretching bands tends to increase as a consequence of strong hydrogen bonding at higher concentrations.

  4. Investigating the Impact of Spatially-Explicit Sub-Pixel Structural Variation on the Assessment of Vegetation Structure from Imaging Spectroscopy Data

    Science.gov (United States)

    Yao, Wei

    Consistent and scalable estimation of vegetation structural parameters from imaging spectroscopy is essential to remote sensing for ecosystem studies, with applications to a wide range of biophysical assessments. NASA has proposed the Hyperspectral Infrared Imager (HyspIRI) imaging spectrometer, which measures the radiance between 380-2500 nm in 10 nm contiguous bands with 60 m ground sample distance (GSD), in support of global vegetation assessment. However, because of the large pixel size on the ground, there is uncertainty as to the effects of sub-pixel vegetation structure on observed radiance. The purpose of this research was to evaluate the link between vegetation structure and imaging spectroscopy spectra. Specifically, the goal was to assess the impact of sub-pixel vegetation density and position, i.e., structural variability, on large-footprint spectral radiances. To achieve this objective, three virtual forest scenes were constructed, corresponding to the actual vegetation structure of the National Ecological Observatory Network (NEON) Pacific Southwest domain (PSW; D17; Fresno, CA). These scenes were used to simulate anticipated HyspIRI data (60 m GSD) using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model, a physics-driven synthetic image generation model developed by the Rochester Institute of Technology (RIT). Airborne Visible / Infrared Imaging Spectrometer (AVIRIS) and NEON's high-resolution imaging spectrometer (NIS) data were used to verify the geometric parameters and physical models. Multiple simulated HyspIRI data sets were generated by varying within-pixel structural variables, such as forest density, tree position, and distribution of trees, in order to assess the impact of sub-pixel structural variation on the observed HyspIRI data. As part of the effort, a partial least squares (PLS) regression model, along with narrow-band vegetation indices (VIs), were used to characterize the sub-pixel vegetation structure from

  5. Vertical E × B drift velocity variations and associated low-latitude ionospheric irregularities investigated with the TOPEX and GPS satellite data

    Directory of Open Access Journals (Sweden)

    I. Horvath

    2003-04-01

    Full Text Available With a well-selected data set, the various events of the vertical E × B drift velocity variations at magnetic-equator-latitudes, the resultant ionospheric features at low-and mid-latitudes, and the practical consequences of these E × B events on the equatorial radio signal propagation are demonstrated. On a global scale, the development of a equatorial anomaly is illustrated with a series of 1995 global TOPEX TEC (total electron content maps. Locally, in the Australian longitude region, some field-aligned TOPEX TEC cross sections are combined with the matching Guam (144.86° E; 13.59° N, geographic GPS (Global Positioning System TEC data, covering the northern crest of the equatorial anomaly. Together, the 1998 TOPEX and GPS TEC data are utilized to show the three main events of vertical E × B drift velocity variations: (1 the pre-reversal enhancement, (2 the reversal and (3 the downward maximum. Their effects on the dual-frequency GPS recordings are documented with the raw Guam GPS TEC data and with the filtered Guam GPS dTEC/min or 1-min GPS TEC data after Aarons et al. (1997. During these E × B drift velocity events, the Port Moresby (147.10° E; - 9.40° N, geographic virtual height or h'F ionosonde data (km, which cover the southern crest of the equatorial anomaly in the Australian longitude region, show the effects of plasma drift on the equatorial ionosphere. With the net (D horizontal (H magnetic field intensity parameter, introduced and called DH or Hequator-Hnon-equator (nT by Chandra and Rastogi (1974, the daily E × B drift velocity variations are illustrated at 121° E (geographic in the Australian longitude region. The results obtained with the various data show very clearly that the development of mid-latitude night-time TEC increases is triggered by the westward electric field as the appearance of such night-time TEC increases coincides with the E × B drift velocity reversal. An explanation is offered with the F

  6. Construction and investigation of 3D vessels net of the brain according to MRI data using the method of variation of scanning plane

    Science.gov (United States)

    Cherevko, A. A.; Yankova, G. S.; Maltseva, S. V.; Parshin, D. V.; Akulov, A. E.; Khe, A. K.; Chupakhin, A. P.

    2016-06-01

    The blood realizes the transport of substances, which are necessary for livelihoods, throughout the body. The assumption about the relationship genotype and structure of vasculature (in particular of brain) is natural. In the paper we consider models of vessel net for two genetic lines of laboratory mice. Vascular net obtained as a result of preprocessing MRI data. MRI scanning is realized using the method of variation of slope of scanning plane, i.e. by several sets of parallel planes specified by different normal vectors. The following special processing allowed to construct models of vessel nets without fragmentation. The purpose of the work is to compare the vascular network models of two different genetic lines of laboratory mice.

  7. Numerical investigation of heat transfer in a laminar flow in a helical pipe filled with a fluid saturated porous medium: the sensitivity to parameter variations

    International Nuclear Information System (INIS)

    Cheng, L.; Kuznetsov, A.V.

    2005-01-01

    This paper presents the first attempt to investigate numerically heat transfer in a helical pipe filled with a fluid saturated porous medium; the analysis is based on the full momentum equation for porous media that accounts for the Brinkman and Forchheimer extensions of the Darcy law as well as for the flow inertia. Numerical computations are performed in an orthogonal helical coordinate system. The effects of the Darcy number, the Forchheimer coefficient as well as the Dean and Germano numbers on the axial flow velocity, secondary flow, temperature distribution, and the Nusselt number are investigated. (authors)

  8. Numerical investigation of heat transfer in a laminar flow in a helical pipe filled with a fluid saturated porous medium: the sensitivity to parameter variations

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, L.; Kuznetsov, A.V. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Mechanical and Aerospace Engineering

    2005-07-01

    This paper presents the first attempt to investigate numerically heat transfer in a helical pipe filled with a fluid saturated porous medium; the analysis is based on the full momentum equation for porous media that accounts for the Brinkman and Forchheimer extensions of the Darcy law as well as for the flow inertia. Numerical computations are performed in an orthogonal helical coordinate system. The effects of the Darcy number, the Forchheimer coefficient as well as the Dean and Germano numbers on the axial flow velocity, secondary flow, temperature distribution, and the Nusselt number are investigated. (authors)

  9. Investigation of the sources and seasonal variations of secondary organic aerosols in PM2.5 in Shanghai with organic tracers

    Science.gov (United States)

    Feng, Jialiang; Li, Man; Zhang, Pan; Gong, Shiyi; Zhong, Mian; Wu, Minghong; Zheng, Mei; Chen, Changhong; Wang, Hongli; Lou, Shengrong

    2013-11-01

    One hundred and forty seasonal PM2.5 samples were collected from January 2010 to January 2011 at one urban site and one suburban site simultaneously in a Chinese megacity, Shanghai, to study the concentrations and seasonal variation of secondary organic aerosols (SOA). Concentrations of water-soluble organic carbon (WSOC) were determined together with organic and elemental carbons. Thirteen organic tracers, including the tracer for biomass burning and tracers for SOA from isoprene, α-pinene, β-caryophyllene and toluene, were measured. EC-based method, WSOC-based method, tracer-based method and PMF modeling were used to estimate the seasonal contributions of secondary organic carbon (SOC) in Shanghai, and the results from the different methods were compared and evaluated. Biomass burning was the major contributor to the measured WSOC in the autumn sampling period, while SOA was the major contributor in the other seasons. The concentrations of the SOA tracers in summer were obviously higher than that in other seasons. It was found that SOC estimated with the tracer-based method accounted for only a small part of the SOC from the WSOC-based method in Shanghai, especially for the winter and spring sampling periods. PMF results showed that a large part of the SOC was associated with sulfate and nitrate but not with the SOA tracers.

  10. A study on investigating the delivery parameter error effect on the variation of patient quality assurance during RapidArc treatment.

    Science.gov (United States)

    Peng, Jiayuan; Zhang, Zhen; Zhou, Lijun; Zhao, Jinfang; Wang, Jiazhou; Kong, Lin; Hu, Weigang

    2013-03-01

    The purpose of this study is to evaluate delivery parameter errors (DPEs) and their impact on clinical dose variation with the Varian RapidArc technique. The dynalog files of 16 head-and-neck patients were retrospectively analyzed to characterize three RapidArc DPEs: dose MU, gantry angle, and MLC gap errors. A total of 64 reconstructed plans were created by creating four variants of each of the original 16 plans (three with the DPEs applied individually and one with the three DPEs combined). These reconstructed plans were compared to the original plans to evaluate the impact of the DPEs on the clinical dose distribution. The mean dose MU, gantry angle, and MLC gap error for all patients were 0.00 ± 0.00 MU, -0.36 ± 0.03°, and 0.00 ± 0.01 mm, respectively. The DPEs had no obvious dosimetric impact on any of the studied dosimetric endpoints except the parotid dose. The gantry angle error, MLC gap error, and combined DPEs changed the parotid Dmean (mean dose) and parotid V30 (volume receiving at least 30 Gy) by 1%-2%. It is feasible to use dose distributions reconstructed from dynalog file data as a quality assurance tool. The dose MU, gantry angle, and MLC errors have only minor effects on the accuracy of the delivered dose.

  11. An experimental investigation of the hemodynamic variations due to aplastic vessels within three-dimensional phantom models of the Circle of Willis.

    LENUS (Irish Health Repository)

    Fahy, Paul

    2013-09-10

    A complete circle of Willis (CoW) is found in approximately 30-50% of the population. Anatomical variations, such as absent or surgically clamped vessels, can result in undesirable flow patterns. These can affect the brain\\'s ability to maintain cerebral perfusion and the formation of cerebral aneurysms. An experimental test system was developed to simulate cerebral physiological conditions through three flexible 3D patient-specific models of complete and incomplete CoW geometries. Flow visualizations were performed with isobaric dyes and the mapped dye streamlines were tracked throughout the models. Three to seven flow impact locations were observed for all configurations, corresponding to known sites for aneurysmal formation. Uni and bi-directional cross-flows occurred along the communicating arteries. The greatest shunting of flow occurred for a missing pre-communicating anterior (A1) and posterior (P1) cerebral arteries. The anterior cerebral arteries had the greatest reduction (15-37%) in efferent flow rates for missing either a unilateral A1 or bilateral P1 segments. The bi-directional cross-flows, with multiple afferent flow mixing, observed along the communicating arteries may explain the propensity of aneurysm formation at these sites. Reductions in efferent flow rates due to aplastic vessel configurations may affect normal brain function.

  12. Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): a comparative morphometric and microscopic investigation of an evolutionary novelty.

    Science.gov (United States)

    Dugon, Michel M; Black, Alexander; Arthur, Wallace

    2012-05-01

    The forcipules of centipedes are the only known example in the animal kingdom of an evolutionary transition from walking legs to venom-injecting appendages. They provide a classic case of an evolutionary novelty under most (but not all) definitions of that concept. Although there is a reasonable literature on forcipules, and on the forcipular segment more generally, it is fragmentary and scattered. Also, many previous studies have been based on a single species and hence have no comparative component. Here, we build on this earlier literature by providing detailed qualitative and quantitative information on the forcipular segments of representatives of the five extant orders of centipedes. Our results reveal notable differences between the orders - as well as considerable variation within some of them. The pattern of inter-group differences can be used to infer, albeit cautiously, a major evolutionary trend from a presumed scutigeromorph-like last common ancestor (LCA), in which the forcipules were probably leg-like (as in present-day scutigeromorphs) to a more specialized claw-like structure with movement restricted to the horizontal plane. This morphological trend may reflect an ecological trend from open-habitat ambush predation to leaf-litter and subterranean predatory opportunism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Comparative Investigation of the Genomic Regions Involved in Antigenic Variation of the TprK Antigen among Treponemal Species, Subspecies, and Strains

    Science.gov (United States)

    Brandt, Stephanie L.; Puray-Chavez, Maritza; Reid, Tara Brinck; Godornes, Charmie; Molini, Barbara J.; Benzler, Martin; Hartig, Jörg S.; Lukehart, Sheila A.; Centurion-Lara, Arturo

    2012-01-01

    Although the three Treponema pallidum subspecies (T. pallidum subsp. pallidum, T. pallidum subsp. pertenue, and T. pallidum subsp. endemicum), Treponema paraluiscuniculi, and the unclassified Fribourg-Blanc treponeme cause clinically distinct diseases, these pathogens are genetically and antigenically highly related and are able to cause persistent infection. Recent evidence suggests that the putative surface-exposed variable antigen TprK plays an important role in both treponemal immune evasion and persistence. tprK heterogeneity is generated by nonreciprocal gene conversion between the tprK expression site and donor sites. Although each of the above-mentioned species and subspecies has a functional tprK antigenic variation system, it is still unclear why the level of expression and the rate at which tprK diversifies during infection can differ significantly among isolates. To identify genomic differences that might affect the generation and expression of TprK variants among these pathogens, we performed comparative sequence analysis of the donor sites, as well as the tprK expression sites, among eight T. pallidum subsp. pallidum isolates (Nichols Gen, Nichols Sea, Chicago, Sea81-4, Dal-1, Street14, UW104, and UW126), three T. pallidum subsp. pertenue isolates (Gauthier, CDC2, and Samoa D), one T. pallidum subsp. endemicum isolate (Iraq B), the unclassified Fribourg-Blanc isolate, and the Cuniculi A strain of T. paraluiscuniculi. Synteny and sequence conservation, as well as deletions and insertions, were found in the regions harboring the donor sites. These data suggest that the tprK recombination system is harbored within dynamic genomic regions and that genomic differences might be an important key to explain discrepancies in generation and expression of tprK variants among these Treponema isolates. PMID:22661689

  14. Investigation of correlation of the variations in land subsidence (detected by continuous GPS measurements and methodological data in the surrounding areas of Lake Urmia

    Directory of Open Access Journals (Sweden)

    K. Moghtased-Azar

    2012-11-01

    Full Text Available Lake Urmia, a salt lake in the north-west of Iran, plays a valuable role in the environment, wildlife and economy of Iran and the region, but now faces great challenges for survival. The Lake is in immediate and great danger and is rapidly going to become barren desert. As a result, the increasing demands upon groundwater resources due to expanding metropolitan and agricultural areas are a serious challenge in the surrounding regions of Lake Urmia. The continuous GPS measurements around the lake illustrate significant subsidence rate between 2005 and 2009. The objective of this study was to detect and specify the non-linear correlation of land subsidence and temperature activities in the region from 2005 to 2009. For this purpose, the cross wavelet transform (XWT was carried out between the two types of time series, namely vertical components of GPS measurements and daily temperature time series. The significant common patterns are illustrated in the high period bands from 180–218 days band (~6–7 months from September 2007 to February 2009. Consequently, the satellite altimetry data confirmed that the maximum rate of linear trend of water variation in the lake from 2005 to 2009, is associated with time interval from September 2007 to February 2009. This event was detected by XWT as a critical interval to be holding the strong correlation between the land subsidence phenomena and surface temperature. Eventually the analysis can be used for modeling and prediction purposes and probably stave off the damage from subsidence phenomena.

  15. SU-G-201-13: Investigation of Dose Variation Induced by HDR Ir-192 Source Global Shift Within the Varian Ring Applicator Using Monte Carlo Methods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y; Cai, J; Meltsner, S; Chang, Z; Craciunescu, O [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: The Varian tandem and ring applicators are used to deliver HDR Ir-192 brachytherapy for cervical cancer. The source path within the ring is hard to predict due to the larger interior ring lumen. Some studies showed the source could be several millimeters different from planned positions, while other studies demonstrated minimal dosimetric impact. A global shift can be applied to limit the effect of positioning offsets. The purpose of this study was to assess the necessities of implementing a global source shift using Monte Carlo (MC) simulations. Methods: The MCNP5 radiation transport code was used for all MC simulations. To accommodate TG-186 guidelines and eliminate inter-source attenuation, a BrachyVision plan with 10 dwell positions (0.5cm step sizes) was simulated as the summation of 10 individual sources with equal dwell times for simplification. To simplify the study, the tandem was also excluded from the MC model. Global shifts of ±0.1, ±0.3, ±0.5 cm were then simulated as distal and proximal from the reference positions. Dose was scored in water for all MC simulations and was normalized to 100% at the normalization point 0.5 cm from the cap in the ring plane. For dose comparison, Point A was 2 cm caudal from the buildup cap and 2 cm lateral on either side of the ring axis. With seventy simulations, 108 photon histories gave a statistical uncertainties (k=1) <2% for (0.1 cm)3 voxels. Results: Compared to no global shift, average Point A doses were 0.0%, 0.4%, and 2.2% higher for distal global shifts, and 0.4%, 2.8%, and 5.1% higher for proximal global shifts, respectively. The MC Point A doses differed by < 1% when compared to BrachyVision. Conclusion: Dose variations were not substantial for ±0.3 cm global shifts, which is common in clinical practice.

  16. Numerical investigation on the variation of welding stresses after material removal from a thick titanium alloy plate joined by electron beam welding

    International Nuclear Information System (INIS)

    Liu, Chuan; Zhang, Jianxun; Wu, Bing; Gong, Shuili

    2012-01-01

    Highlights: → After less materials removal from the top, stresses on the bottom remain unchanged. → The transverse stress within the weld decreases significantly with material removal. → Local material removal does not influence the longitudinal stress significantly. -- Abstract: The stress modification after material removal from a 50 mm thick titanium alloy plate jointed by electron beam welding (EBW) was investigated through the finite element method (FEM). The welding experiment and milling process were carried out to experimentally determine the stresses induced by EBW and their modification after local material removal. The modification of as-welded stresses due to the local material removal method and the whole layer removal method was discussed with the finite element analysis. Investigated results showed that with less materials removal from the top, the stresses on the bottom surface remain almost unchanged; after material removal from the top and bottom part, the transverse stress on the newly-formed surface decreases significantly as compared to the as-welded stresses at the same locations; however, the stress modification only occurs at the material removal region in the case of local region removal method; the longitudinal stress decreases with the whole layer removal method while remains almost unchanged with the local region removal method.

  17. Sediment budget and interannual variations of suspended sediment load in the Rio Cordon (Italy). Three decades of monitoring and investigations (1987-2014).

    Science.gov (United States)

    García-Rama, Adriana; Rainato, Riccardo; Mao, Luca; Picco, Lorenzo; Aristide Lenzi, Mario

    2015-04-01

    This work shows the results of 28 years of measurements carried out in the Rio Cordon catchment, an Alpine watershed where a measuring station continuously recorded water discharge, bedload and suspended sediment transport since 1987. Hourly values of discharge and suspended sediment transport (or 5 min interval during flood events) have been studied throughout the whole study period. Annual and seasonal variations of suspended sediment load during the study period were analyzed along with their contribution to the total sediment yield. Comparing these almost three decades, the highest suspended solid transport occurred in 1994, 2001, 1987, 1998, 2002 and 2009, during which it was 2521.5, 1568.5, 792, 745, 551 and 514.8 t year-1, respectively. Summer and autumn contributions were significant in 1989, 1994, 1996, 1998, 2002, and 2005; on the other hand 2001 was characterized by a snowmelt flood that generated almost all the suspended load. A notable variability of the suspended solid transport can be observed taking in count snowmelt floods. Also 1987, 2001, 2008, 2009 and 2010 are characterized by a very important role of this kind of runoff. Data collected in the Rio Cordon for 28 years show that 75.2% of the total sediment load (10597.8 t of 14088.8 t) was due to suspended sediment transport. In 1994 and 2001, a large portion of the suspended sediment load was mainly supplied during the flood events that occurred in September 1994 and May 2001, which produced 198 and 1017.5 t respectively. Averaging 28 years of data, the mean annual specific sediment yield turns out to be around 102,9 t km-2 year-1. However, this value includes the 1986-1993 period characterized by ordinary flood events during which de mean sediment production was 65.34 t km-2 year-1, the massive sediment yield in 1994 (803.4 t km-2 year-1), the 1995-2000 period (93.2 t km-2 year-1), the 2001 (343.8 km-2 year-1) and the 2002-2014 period(54.5 t km-2 year-1). The highest values correspond to 1994

  18. Investigation of Relative Time Constant Influence of Inertial Part of Superheater on Quality of Steam Temperature Control Behind Boiler in Broad Band of Loading Variations

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2008-01-01

    Full Text Available The paper is devoted to computational investigation of influence relative time constant of an object which changes in broad band on quality of steam temperature control behind a boiler with due account of value of regulating action in the system with PI- and PID- regulator. The simulation has been based on a single-loop automatic control system (ACS. It has been revealed that the less value of the relative time constant of an object leads to more integral control error in system with PID- regulator while operating external ACS perturbation. Decrease of numerical value of relative time constant of an object while operating external perturbation causes decrease of relative time concerning appearance of maximum dynamic control error from common relative control time.

  19. Using Ecological Momentary Assessment to Investigate Short-Term Variations in Sexual Functioning in a Sample of Peri-Menopausal Women from Iran

    Science.gov (United States)

    Pakpour, Amir H.; Yekaninejad, Mir Saeed; Pallich, Gianandrea; Burri, Andrea

    2015-01-01

    The investigation of short-term changes in female sexual functioning has received little attention so far. The aims of the study were to gain empirical knowledge on within-subject and within- and across-variable fluctuations in women’s sexual functioning over time. More specifically, to investigate the stability of women´s self-reported sexual functioning and the moderating effects of contextual and interpersonal factors. A convenience sample of 206 women, recruited across eight Health care Clinics in Rasht, Iran. Ecological momentary assessment was used to examine fluctuations of sexual functioning over a six week period. A shortened version of the Female Sexual Function Index (FSFI) was applied to assess sexual functioning. Self-constructed questions were included to assess relationship satisfaction, partner’s sexual performance and stress levels. Mixed linear two-level model analyses revealed a link between orgasm and relationship satisfaction (Beta = 0.125, P = 0.074) with this link varying significantly between women. Analyses further revealed a significant negative association between stress and all six domains of women’s sexual functioning. Women not only reported differing levels of stress over the course of the assessment period, but further differed from each other in how much stress they experienced and how much this influenced their sexual response. Orgasm and sexual satisfaction were both significantly associated with all other domains of sexual function (Psexual functioning (Psatisfaction had a significant effect on all domains of the sexual response (P<0.001). Overall, our findings support the new group of criteria introduced in the DSM-5, called “associated features” such as partner factors and relationship factors. Consideration of these criteria is important and necessary for clinicians when diagnosing FSD. PMID:25692787

  20. Using ecological momentary assessment to investigate short-term variations in sexual functioning in a sample of peri-menopausal women from Iran.

    Directory of Open Access Journals (Sweden)

    Amir H Pakpour

    Full Text Available The investigation of short-term changes in female sexual functioning has received little attention so far. The aims of the study were to gain empirical knowledge on within-subject and within- and across-variable fluctuations in women's sexual functioning over time. More specifically, to investigate the stability of women´s self-reported sexual functioning and the moderating effects of contextual and interpersonal factors. A convenience sample of 206 women, recruited across eight Health care Clinics in Rasht, Iran. Ecological momentary assessment was used to examine fluctuations of sexual functioning over a six week period. A shortened version of the Female Sexual Function Index (FSFI was applied to assess sexual functioning. Self-constructed questions were included to assess relationship satisfaction, partner's sexual performance and stress levels. Mixed linear two-level model analyses revealed a link between orgasm and relationship satisfaction (Beta = 0.125, P = 0.074 with this link varying significantly between women. Analyses further revealed a significant negative association between stress and all six domains of women's sexual functioning. Women not only reported differing levels of stress over the course of the assessment period, but further differed from each other in how much stress they experienced and how much this influenced their sexual response. Orgasm and sexual satisfaction were both significantly associated with all other domains of sexual function (P<0.001. And finally, a link between partner performance and all domains of women`s sexual functioning (P<0.001 could be detected. Except for lubrication (P = 0.717, relationship satisfaction had a significant effect on all domains of the sexual response (P<0.001. Overall, our findings support the new group of criteria introduced in the DSM-5, called "associated features" such as partner factors and relationship factors. Consideration of these criteria is important and necessary for

  1. Variational principles

    CERN Document Server

    Moiseiwitsch, B L

    2004-01-01

    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  2. Variations of the Functional Brain Network Efficiency in a Young Clinical Sample within the Autism Spectrum: A fNIRS Investigation

    Directory of Open Access Journals (Sweden)

    Yanwei Li

    2018-02-01

    Full Text Available Autism is a neurodevelopmental disorder with dimensional behavioral symptoms and various damages in the structural and functional brain. Previous neuroimaging studies focused on exploring the differences of brain development between individuals with and without autism spectrum disorders (ASD. However, few of them have attempted to investigate the individual differences of the brain features among subjects within the Autism spectrum. Our main goal was to explore the individual differences of neurodevelopment in young children with Autism by testing for the association between the functional network efficiency and levels of autistic behaviors, as well as the association between the functional network efficiency and age. Forty-six children with Autism (ages 2.0–8.9 years old participated in the current study, with levels of autistic behaviors evaluated by their parents. The network efficiency (global and local network efficiency were obtained from the functional networks based on the oxy-, deoxy-, and total-Hemoglobin series, respectively. Results indicated that the network efficiency decreased with age in young children with Autism in the deoxy- and total-Hemoglobin-based-networks, and children with a relatively higher level of autistic behaviors showed decreased network efficiency in the oxy-hemoglobin-based network. Results suggest individual differences of brain development in young children within the Autism spectrum, providing new insights into the psychopathology of ASD.

  3. Investigation on the variation of channel resistance and contact resistance of SiZnSnO semiconductor depending on Si contents using transmission line method

    Science.gov (United States)

    Lee, Byeong Hyeon; Han, Sangmin; Lee, Sang Yeol

    2018-01-01

    Amorphous silicon-zinc-tin-oxide (a-SZTO) thin film transistors (TFTs) have been fabricated depending on the silicon ratio in channel layers. The a-SZTO TFT exhibited high electrical properties, such as high mobility of 23 cm2 V-1 s-1, subthreshold swing of 0.74 V/decade and ION/OFF of 2.8 × 108, despite of the addition of Si suppressor. The physical mechanism on the change of the sheet resistance and the contact resistance in a-SZTO TFT has been investigated and proposed closely related with the Si ratio. Both resistances were increased as increasing Si ratio, which clearly indicated that the role of Si is a carrier suppressor directly leading to the increase of channel and contact resistances. To explain the role of Si as a carrier suppressor, the conduction band offset mechanism has been also proposed depending on the change of carrier concentration in channel layer and at the interface between electrode and channel layer. 2007.01-2011.12 Senior Researcher at korea institute of science and technology (KOREA). 2008.01-2011.12 Professor at University of Science and Technology (KOREA). 1995.01-2007.12 Professor at Yonsei University (KOREA). 2002.01-2003.12 Inviting Researcher at Los Alamos National Lab (USA). 1993.01-1995.12 Senior Researcher at Electronics and Telecommunications Research Institute (KOREA). 1992.01-1993.01 Research Associate at State University of New York at Buffalo (USA).

  4. Variation in external representations as part of the classroom lecture:An investigation of virtual cell animations in introductory photosynthesis instruction.

    Science.gov (United States)

    Goff, Eric E; Reindl, Katie M; Johnson, Christina; McClean, Phillip; Offerdahl, Erika G; Schroeder, Noah L; White, Alan R

    2017-05-01

    The use of external representations (ERs) to introduce concepts in undergraduate biology has become increasingly common. Two of the most prevalent are static images and dynamic animations. While previous studies comparing static images and dynamic animations have resulted in somewhat conflicting findings in regards to learning outcomes, the benefits of each have been shown individually. Using ERs developed by the Virtual Cell Animation project, we aim to further investigate student learning using different ERs as part of an introductory biology lecture. We focus our study on the topic of photosynthesis as reports have noted that students struggle with a number of basic photosynthesis concepts. Students (n = 167) in ten sections of introductory biology laboratory were introduced to photosynthesis concepts by instructional lectures differing only in the format of the embedded ERs. Normalized gain scores were calculated, showing that students who learned with dynamic animations outperformed students who learned from static images on the posttest. The results of this study provide possible instructional guidelines for those delivering photosynthesis instruction in the introductory biology classroom. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):226-234, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

  5. An electrochemical investigation of TMJ implant metal alloys in an artificial joint fluid environment: the influence of pH variation.

    Science.gov (United States)

    Royhman, Dmitry; Radhakrishnan, Rashmi; Yuan, Judy Chia-Chun; Mathew, Mathew T; Mercuri, Louis G; Sukotjo, Cortino

    2014-10-01

    To investigate the corrosion behaviour of commonly used TMJ implants alloys (CoCrMo and Ti6Al4V) under simulated physiological conditions. Corrosion behaviour was evaluated using standard electrochemical corrosion techniques and galvanic corrosion techniques as per ASTM standards. Standard electrochemical tests (E(corr), I(corr), R(p) and C(f)) were conducted in bovine calf serum (BCS), as a function of alloys type and different pHs. Galvanic corrosion tests were conducted in BCS at a pH of 7.6. Alloy surfaces were characterized using white-light interferometry (WLI) and scanning electron microscopy (SEM). The potentiodynamic test results exhibited the enhanced passive layer growth and a better corrosion resistance of Ti6Al4V compared to CoCrMo. Electrochemical impedance spectroscopy measurements demonstrated the influence of protein as a function of pH on corrosion mechanisms/kinetics. Galvanic coupling was not a major contributor to corrosion. SEM and WLI images demonstrated a significantly higher in surface roughness in CoCrMo after corrosion. The results of this study suggest that Ti6Al4V shows superior corrosion behaviour to CoCrMo due to its strong passive layer, simulated joint fluid components can affect the electrochemical nature of the metal/electrolyte interface as a function of pH, and the galvanic effect of coupling CoCrMo and Ti6Al4V in a single joint is weak. Published by Elsevier Ltd.

  6. The association between Mediterranean Diet Score and glucokinase regulatory protein gene variation on the markers of cardiometabolic risk: an analysis in the European Prospective Investigation into Cancer (EPIC)-Norfolk study.

    Science.gov (United States)

    Sotos-Prieto, Mercedes; Luben, Robert; Khaw, Kay-Tee; Wareham, Nicholas J; Forouhi, Nita G

    2014-07-14

    Consumption of a Mediterranean diet (MD) and genetic variation in the glucokinase regulatory protein (GCKR) gene have been reported to be associated with TAG and glucose metabolism. It is uncertain whether there is any interaction between these factors. Therefore, the aims of the present study were to test the association of adherence to a MD and rs780094 (G>A) SNP in the GCKR gene with the markers of cardiometabolic risk, and to investigate the interaction between genetic variation and MD adherence. We studied 20 986 individuals from the European Prospective Investigation into Cancer (EPIC)-Norfolk study. The relative Mediterranean Diet Score (rMED: range 0-18) was used to assess MD adherence. Linear regression was used to estimate the association between the rMED, genotype and cardiometabolic continuous traits, adjusting for potential confounders. In adjusted analyses, we observed independent associations of MD adherence and genotype with cardiometabolic risk, with the highest risk group (AA genotype; lowest rMED) having higher concentrations of TAG, total cholesterol and apoB (12·5, 2·3 and 3·1%, respectively) v. those at the lowest risk (GG genotype; highest rMED). However, the associations of MD adherence with metabolic markers did not differ by genotype, with no significant gene-diet interactions for lipids or for glycated Hb. In conclusion, we found independent associations of the rMED and of the GCKR genotype with cardiometabolic profile, but found no evidence of interaction between them.

  7. Investigations of the Diurnal Variation of Vertical HCHO Profiles Based on MAX-DOAS Measurements in Beijing: Comparisons with OMI Vertical Column Data

    Directory of Open Access Journals (Sweden)

    Hanlim Lee

    2015-11-01

    Full Text Available An investigation into the diurnal characteristics of vertical formaldehyde (HCHO profiles was conducted based on multi-axis differential optical absorption spectroscopy (MAX-DOAS measurements in Beijing during the CAREBEIJING campaign, covering a month-long period through August and September 2006. Vertical HCHO profiles were retrieved based on a combined differential optical absorption spectroscopy (DOAS technique and an optimal estimation method (OEM. The HCHO volume-mixing ratio (VMR was found to be highest in the layer from the surface up to an altitude of 1 km and to decrease with altitude above this layer. In all retrieved profiles, HCHO was not detected in the layer from 3–4 km. Over the diurnal cycle, the HCHO VMR values were generally highest at 15:00 local time (LT and were lower in the morning and late afternoon. The mean HCHO VMRs were 6.17, 1.82, and 0.80 ppbv for the 0–1, 1–2, and 2–3-km layers, respectively, at 15:00 LT, whereas they were 3.54 (4.79, 1.06 (1.43, and 0.46 (0.63 ppbv for the 0–1, 1–2, and 2–3-km layers, respectively, at 09:00 (17:00 LT. The HCHO VMRs reached their highest values at 15:00 LT on August 19, which were 17.71, 5.20, and 2.31 ppbv for the 0–1, 1–2, and 2–3-km layers, respectively. This diurnal pattern implies that the photo-oxidation of volatile organic compounds (VOCs was most active at 15:00 LT for several days during the campaign period. In a comparison of the derived HCHO VCDs with those obtained from the Ozone Monitoring Instrument (OMI measurements, the HCHO vertical column density (VCD values obtained from the OMI measurements tend to be smaller than those from the MAX-DOAS.

  8. Investigation of FOXP3 genetic variations at positions -2383 C/T and IVS9+459 T/C in southern Iranian patients with lung carcinoma

    Directory of Open Access Journals (Sweden)

    Maryam Fazelzadeh Haghighi

    2015-05-01

    Full Text Available Objective(s: FOXP3 gene is an X-linked gene that encodes FOXP3 protein, an essential transcription factor in CD4+CD25+FOXP3+ regulatory T (Treg cells.  We aimed, in the present study, to investigate the association of two FOXP3 polymorphisms, -2383 C/T (rs3761549 and IVS9+459 T/C (rs2280883, with lung cancer. Materials and Methods:  In a case-control study we analyzed genotypes and alleles frequencies at -2383 C/T and IVS9+459 T/C positions in 156 patients with lung cancer and 156 age and sex matched healthy controls in Southern Iranian population, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP methods. The data were verified by direct automated DNA sequencing. Results: The frequency of -2383 T allele was significantly higher in the patients than in the control group (11.8% versus 5.9%, P-value=0.04, OR=2.13, 95%CI=1.04-4.54. T allele frequency at IVS9+459 T/C position was higher, compared to the controls, in the patients who presented the disease over 55 years old (69.9% versus 59.1%, P-value=0.04, OR=1.61, 95%CI=1.01-2.55 and also in SCLC patients (77.8% versus 59.1%, P-value=0.03, OR=2.42, 95%CI=1.05-5.59. No significant differences were found in the genotypes and haplotypes distributions between the cases and controls. A high degree of linkage disequilibrium was observed between two polymorphisms.  Conclusion: As the first study dealing with -2383 C/T and IVS9+459 T/C in lung cancer, our data conclusively suggest the association of -2383 T allele with susceptibility to lung cancer in Iranian population. The association of IVS9+459 T allele with susceptibility to lung cancer in old patients suggests the age-dependent effects of FOXP3 gene on cancer occurrence.

  9. Investigation of the seasonal and local time variations of the high-altitude sporadic Na layer (Nas) formation and the associated midlatitude descending E layer (Es) in lower E region

    Science.gov (United States)

    Yuan, T.; Wang, Jihong; Cai, Xuguang; Sojka, J.; Rice, D.; Oberheide, J.; Criddle, N.

    2014-07-01

    Recent studies have suggested that the major reservoir for the sporadic sodium layer (Nas) above 95 km in altitude is likely the sodium ion (Na+) within the sporadic E layer (Es) in the lower E region. However, theoretical and laboratory works have demonstrated that the metal ion's neutralization process is quite difficult above 100 km, while intensive neutral metal layers are consistently observed in the lower E region between 100 km and 125 km. In this paper, the multiyear observations of a Na lidar and an ionosonde at Utah State University (41.7°N, 111.8°W) and the nearby Bear Lake Observatory (41.9°N, 111.4°W) are utilized to understand their seasonal and local time variations. The comparison study between this set of the Nas and the nocturnal Nas observations in Beijing China (40.2°N, 116.1°E) reveals similar variations, but major differences are also noticed. To investigate the mechanism of these variations, the Hamburg Model of the Neutral and Ionized Atmosphere and the Climatological Tidal Model of the Thermosphere are utilized to simulate the ion vertical drift in the lower E region. The simulation shows that the lower E region is dominated by convergence of metal ions in summer, and ion diffusion prevails during winter. The tidal wind modulates the ion vertical drift speed and increases the likelihood of Es evolution at certain local times during the summer, while the tidal components of atmospheric density facilitate Nas formation by neutralizing the Na+ within the Es.

  10. Investigation of Biochemical Variation in Operational Aircrew.

    Science.gov (United States)

    1986-12-01

    literature relating activation of the pituitary-adreno- 7V cortical axis to stress (1- 5 ). The increasing scores on both Factorsl and 4 observed in the...kaetosteroids, 17- hydroxycorticoids, and 5 - hydroxyindole in men exhibiting a particular behavior pattern (A) associated with high incidence of clinical...Prepared for USAF SCHOOL OF AEROSPACE MEDICINE Aerospace Medical Division (AFSC) Brooks Air Force Base, TX 78235-5301 1 - . . . UNCLAS SIFITED _____ 5

  11. Height dependence of secondary cosmic ray variations

    International Nuclear Information System (INIS)

    Belov, A.V.; Dorman, L.I.; Sirotina, I.V.

    1986-01-01

    Altitude dependences of coupling coefficients and secondary cosmic ray variations are investigated. The partial and variational barometric coefficients are calculated according to data on coupling coefficients of a neutron component. Application of data on altitude dependence of variations for calculation of barometric coefficient changes and for determination of a rigidity primary variation spectrum is discussed

  12. SU-F-J-55: Feasibility of Supraclavicular Field Treatment by Investigating Variation of Junction Position Between Breast Tangential and Supraclavicular Fields for Deep Inspiration Breath Hold (DIBH) Left Breast Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, H; Sarkar, V; Paxton, A; Rassiah-Szegedi, P; Huang, Y; Szegedi, M; Huang, L; Su, F; Salter, B [University Utah, Salt Lake City, UT (United States)

    2016-06-15

    Purpose: To explore the feasibility of supraclavicular field treatment by investigating the variation of junction position between tangential and supraclavicular fields during left breast radiation using DIBH technique. Methods: Six patients with left breast cancer treated using DIBH technique were included in this study. AlignRT system was used to track patient’s breast surface. During daily treatment, when the patient’s DIBH reached preset AlignRT tolerance of ±3mm for all principle directions (vertical, longitudinal, and lateral), the remaining longitudinal offset was recorded. The average with standard-deviation and the range of daily longitudinal offset for the entire treatment course were calculated for all six patients (93 fractions totally). The ranges of average ± 1σ and 2σ were calculated, and they represent longitudinal field edge error with the confidence level of 68% and 95%. Based on these longitudinal errors, dose at junction between breast tangential and supraclavicular fields with variable gap/overlap sizes was calculated as a percentage of prescription (on a representative patient treatment plan). Results: The average of longitudinal offset for all patients is 0.16±1.32mm, and the range of longitudinal offset is −2.6 to 2.6mm. The range of longitudinal field edge error at 68% confidence level is −1.48 to 1.16mm, and at 95% confidence level is −2.80 to 2.48mm. With a 5mm and 1mm gap, the junction dose could be as low as 37.5% and 84.9% of prescription dose; with a 5mm and 1mm overlap, the junction dose could be as high as 169.3% and 117.6%. Conclusion: We observed longitudinal field edge error at 95% confidence level is about ±2.5mm, and the junction dose could reach 70% hot/cold between different DIBH. However, over the entire course of treatment, the average junction variation for all patients is within 0.2mm. The results from our study shows it is potentially feasible to treat supraclavicular field with breast tangents.

  13. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  14. Randomized and comparative study between two intra-hospital exercise programs for heart transplant patients

    Directory of Open Access Journals (Sweden)

    Tatiana Satie Kawauchi

    2013-09-01

    Full Text Available OBJECTIVE: To compare the effects of two physical therapy exercise in-hospital programs in pulmonary function and functional capacity of patients in the postoperative period of heart transplantation. METHODS: Twenty-two heart transplanted patients were randomized to the control group (CG, n=11 and training group (TG, n=11. The control group conducted the exercise program adopted as routine in the institution and the training group has had a protocol consisting of 10 stages, with incremental exercises: breathing exercises, resistance training, stretching and walking. The programs began on the first day after extubation and stretched until hospital discharge. Assessed pulmonary function, distance walked in six minutes walk test (6MWT and peripheral muscle strength by one repetition maximum test (1RM. RESULTS: Similar behavior was observed between the two groups treated, with statistically significant increases between the first and second test of the following variables: FVC (59% in CG and 35.2% in TG; MIP (8.6% in CG and 53.5% in TG, MEP (28.8% in CG and 40.7% in TG and 6MWT (44.5% in CG and 31.4% in TG. There was an increase of peripheral strength by 1RM test, over time, to the muscle groups of the elbow flexors, shoulder flexors, hip abductors and knee flexors. CONCLUSION: Heart transplant patients benefit from exercise programs in hospital, regardless of the program type applied. A new training proposal did not result in superiority compared to routine programme applied. Exercise protocols provided improves in ventilatory variables and functional capacity of this population.

  15. Randomized and comparative study between two intra-hospital exercise programs for heart transplant patients.

    Science.gov (United States)

    Kawauchi, Tatiana Satie; Almeida, Patricia Oliva de; Lucy, Karen Rodrigues; Bocchi, Edimar Alcides; Feltrim, Maria Ines Zanetti; Nozawa, Emilia

    2013-01-01

    To compare the effects of two physical therapy exercise in-hospital programs in pulmonary function and functional capacity of patients in the postoperative period of heart transplantation. Twenty-two heart transplanted patients were randomized to the control group (CG, n=11) and training group (TG, n=11). The control group conducted the exercise program adopted as routine in the institution and the training group has had a protocol consisting of 10 stages, with incremental exercises: breathing exercises, resistance training, stretching and walking. The programs began on the first day after extubation and stretched until hospital discharge. Assessed pulmonary function, distance walked in six minutes walk test (6MWT) and peripheral muscle strength by one repetition maximum test (1RM). Similar behavior was observed between the two groups treated, with statistically significant increases between the first and second test of the following variables: FVC (59% in CG and 35.2% in TG); MIP (8.6% in CG and 53.5% in TG), MEP (28.8% in CG and 40.7% in TG) and 6MWT (44.5% in CG and 31.4% in TG). There was an increase of peripheral strength by 1RM test, over time, to the muscle groups of the elbow flexors, shoulder flexors, hip abductors and knee flexors. Heart transplant patients benefit from exercise programs in hospital, regardless of the program type applied. A new training proposal did not result in superiority compared to routine programme applied. Exercise protocols provided improves in ventilatory variables and functional capacity of this population.

  16. The importance of investigation of anatomic variations in the ethmoid cells by computerized tomography in the planning of endoscopic nasal surgery; A importancia da investigacao de variacoes anatomicas das celulas etmoidais atraves da tomografia computadorizada no planejamento da cirurgia endoscopica nasal

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Cristiane Regina; Wafae, Nader; Nascimento, Sergio Ricardo Rios; Camelo, Julio Cesar; Maciel, Luana Teixeira; Consolari, Mario Agostinho Severo [Centro Universitario Sao Camilo, Sao Paulo, SP (Brazil)], e-mail: crisruiz@saocamilo-sp.br, e-mail: riosnascimento@uol.com.br

    2009-01-15

    The ethmoidal cells comprise many cavities that show many anatomical variations. Some of these variations deserve special attention when associated with sinusitis and the need of surgery. Computed tomography, considered a gold standard on the pathological investigation of the nasal cavity and the anatomic description of paranasal sinus, offers information about these cells, essential to minimize the surgical risks. The authors present a bibliographic revision of the importance of computed tomography on the investigation of anatomic variations of ethmoid cells. Not recurrent cells in all individuals, like Haller's cells, Onodi's cells and pneumatization of agger nasi, will do the endoscopic approach with precaution. The ethmoidal roof evaluation will result in more safety on the upper limits of the nasal cavity. The size and pneumatization level of ethmoidal bulla, ethmoidal crest, and middle nasal concha are important on the evaluation of the endoscopic accesses and the gravity of the stroked pathology and even diagnose your origin. (author)

  17. Variational and quasi-variational inequalities in mechanics

    CERN Document Server

    Kravchuk, Alexander S

    2007-01-01

    The essential aim of the present book is to consider a wide set of problems arising in the mathematical modelling of mechanical systems under unilateral constraints. In these investigations elastic and non-elastic deformations, friction and adhesion phenomena are taken into account. All the necessary mathematical tools are given: local boundary value problem formulations, construction of variational equations and inequalities, and the transition to minimization problems, existence and uniqueness theorems, and variational transformations (Friedrichs and Young-Fenchel-Moreau) to dual and saddle-point search problems. Important new results concern contact problems with friction. The Coulomb friction law and some others are considered, in which relative sliding velocities appear. The corresponding quasi-variational inequality is constructed, as well as the appropriate iterative method for its solution. Outlines of the variational approach to non-stationary and dissipative systems and to the construction of the go...

  18. Variational principles for locally variational forms

    International Nuclear Information System (INIS)

    Brajercik, J.; Krupka, D.

    2005-01-01

    We present the theory of higher order local variational principles in fibered manifolds, in which the fundamental global concept is a locally variational dynamical form. Any two Lepage forms, defining a local variational principle for this form, differ on intersection of their domains, by a variationally trivial form. In this sense, but in a different geometric setting, the local variational principles satisfy analogous properties as the variational functionals of the Chern-Simons type. The resulting theory of extremals and symmetries extends the first order theories of the Lagrange-Souriau form, presented by Grigore and Popp, and closed equivalents of the first order Euler-Lagrange forms of Hakova and Krupkova. Conceptually, our approach differs from Prieto, who uses the Poincare-Cartan forms, which do not have higher order global analogues

  19. Exploring language variation across Europe

    DEFF Research Database (Denmark)

    Hovy, Dirk; Johannsen, Anders Trærup

    2016-01-01

    Language varies not only between countries, but also along regional and sociodemographic lines. This variation is one of the driving factors behind language change. However, investigating language variation is a complex undertaking: the more factors we want to consider, the more data we need....... Traditional qualitative methods are not well-suited to do this, an thus restricted to isolated factors. This reduction limits the potential insights, and risks attributing undue importance to easily observed factors. While there is a large interest in linguistics to improve upon such studies, it requires...... training in both variational linguistics and computational methods, a combination that is still not common. We take a first step here to alleviate the problem by providing an interface to explore large-scale language variation along several socio-demographic factors without programming knowledge. It makes...

  20. A numerical investigation of the sCO2 recompression cycle off-design behaviour, coupled to a sodium cooled fast reactor, for seasonal variation in the heat sink temperature

    International Nuclear Information System (INIS)

    Floyd, J.; Alpy, N.; Moisseytsev, A.; Haubensack, D.; Rodriguez, G.; Sienicki, J.; Avakian, G.

    2013-01-01

    Highlights: • Year-round behaviour of the supercritical CO 2 recompression cycle is simulated. • Behaviour of the system was uncertain due to large changes in the fluid properties. • Cycle thermodynamic optimisation and component preliminary designs were performed. • No off design cycle stability issues, compressors operate away from surge region. • Independent speed control of compressors maintains power and cycle efficiency. -- Abstract: Supercritical CO 2 cycles are particularly attractive for Generation IV Sodium-Cooled Fast Reactors (SFRs) as they can be simple and compact, but still offer steam-cycle equivalent efficiency while also removing potential for Na/H 2 O reactions. However, CO 2 thermophysical properties are very sensitive close to the critical point which raises, in particular, questions about the compressor and so cycle off-design behaviour when subject to inevitable temperature increases that result from seasonal variations in the heat sink temperature. This publication reports the numerical investigation of such an issue that has been performed using the Plant Dynamics Code (ANL, USA), the cycle being optimised for the next French SFR, ASTRID (1500 MW th ), as a test-case. On design, the net plant efficiency is 42.2% for a high pressure (25 MPa) turbine with an inlet temperature of 515 °C and considering a cycle low temperature of 35 °C. The off-design cycle behaviour is studied based on preliminary designs for the main components and assuming the use of a fixed heat sink flow rate. First results obtained using a common fixed shaft speed for all turbomachines, without any other active control, show no stability issues and roughly constant density (and volumetric flow rate) at the main compressor inlet for the range of heat sink temperature considered (21–40 °C). This occurs because the new stationary states are found without requiring a significant shift of mass to the higher pressure level, meaning the compressor inlet pressure

  1. Language Variation and Score Variation in the Testing of English Language Learners, Native Spanish Speakers

    Science.gov (United States)

    Solano-Flores, Guillermo; Li, Min

    2009-01-01

    We investigated language variation and score variation in the testing of English language learners, native Spanish speakers. We gave students the same set of National Assessment of Educational Progress mathematics items in both their first language and their second language. We examined the amount of score variation due to the main and interaction…

  2. Variational Monte Carlo Technique

    Indian Academy of Sciences (India)

    ias

    RESONANCE ⎜ August 2014. GENERAL ⎜ ARTICLE. Variational Monte Carlo Technique. Ground State Energies of Quantum Mechanical Systems. Sukanta Deb. Keywords. Variational methods, Monte. Carlo techniques, harmonic os- cillators, quantum mechanical systems. Sukanta Deb is an. Assistant Professor in the.

  3. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  4. Investigation of spectral distribution and variation of irradiance with the passage time of CSI lamps which constitute a solar simulator; Solar simulator ni shiyosuru CSI lamp no supekutoru bunpu, hosha shodo no keiji henka ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, T.; Yamada, T.; Noguchi, T. [Japan Quality Assurance Organization, Tokyo (Japan)

    1997-11-25

    Study was made on time-variation of the performance of CSI lamps for solar simulators. In order to accurately evaluate the standard heat collection performance of solar systems in a room, MITI installed an artificial solar light source in the Solar Techno-Center of Japan Quality Assurance Organization for trial use and evaluation. CSI lamp is superior in durability, and can simulate the solar light in the daytime. The light source is composed of 72 metal halide lamps of 1kW arranged in a plane of 3.5times3.5m. The study result on time-variation of a spectral distribution and irradiance by intermittent switching of lamps showed a sufficient durability of 2000h. To ensure the accuracy of a solar heat collector measurement system enough, periodic calibration is being carried out using reference goods. To ensure the reliability and stability for a switching system, periodic maintenance of a power source, stabilizer and electric system is also being carried out in addition to CSI lamps. The stable irradiance and accuracy are being kept by such maintenance and periodic exchange of lamps. 6 figs., 4 tabs.

  5. Groupoids, Discrete Mechanics, and Discrete Variation

    International Nuclear Information System (INIS)

    Guo Jiafeng; Jia Xiaoyu; Wu Ke; Zhao Weizhong

    2008-01-01

    After introducing some of the basic definitions and results from the theory of groupoid and Lie algebroid, we investigate the discrete Lagrangian mechanics from the viewpoint of groupoid theory and give the connection between groupoids variation and the methods of the first and second discrete variational principles

  6. Approximate solutions to variational inequalities and applications

    Directory of Open Access Journals (Sweden)

    M. Beatrice Lignola

    1994-11-01

    Full Text Available The aim of this paper is to investigate two concepts of approximate solutions to parametric variational inequalities in topological vector spaces for which the corresponding solution map is closed graph and/or lower semicontinuous and to apply the results to the stability of optimization problems with variational inequality constrains.

  7. Seasonal variations in hospital admissions for mania

    DEFF Research Database (Denmark)

    Medici, Clara Reece; Vestergaard, Claus Høstrup; Hadzi-Pavlovic, Dusan

    2016-01-01

    BACKGROUND: Bipolar disorder is characterized by a seasonal pattern with emerging evidence that weather conditions may trigger symptoms. Thus, our aims were to investigate if year-to-year variations in admissions with mania correlated with year-to-year variations in key meteorological variables, ...

  8. Seasonal variation in chromium hexavalent and copper ...

    African Journals Online (AJOL)

    Seasonal variation in heavy metal contamination of groundwater in the Jimeta- Yola area was investigated. The objectives of the study were to determine the seasonal variation in heavy metal contamination and to determine the influence of anthropogenic activities on heavy metal contamination. Groundwater samples were ...

  9. Investigation of neutronic and safety parameters variation in 5 MW research reactor due to U{sub 3}O{sub 8}Al fuel conversion to ThO{sub 2} + U{sub 3}O{sub 8}Al

    Energy Technology Data Exchange (ETDEWEB)

    Gholamzadeh, Zohreh; Alipoor, Zahra; Mirvakili, Seyed Mohammad [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Reactor Research School; Feghhi, Seyed Amir Hossein [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Radiation Application; Vahedi, M.; Bagheri, H. [Univ. of Science and Technology, Tehran (Iran, Islamic Republic of). Energy Dept.; Tenreiro, Claudio [Talca Univ. (Chile). Energy Dept.

    2017-05-15

    Thorium-based fuels could comprise several advantages and are being investigated as a potentially competitive option with uranium-based fuels for research or power reactors. The present study investigates computationally the application of two different thorium-based fuels in a research reactor. Void and temperature reactivity coefficients, safety factor, power peaking factor, neutron generation time, effective delayed neutron fraction and {sup 135}Xe worth parameter were investigated for the fuel conversions. The results showed both the investigated fuels would not significantly disturb neutronic and safety parameters of the modeled core in comparison with its routine fuel loading. However, 235-enriched thorium based fuel concluded in noticeably reduction of High Level Waste (HLW) but 233-enriched type could be taken in attention because of its longer fuel cycle (∝15 %) and integrated neutron flux (∝23 %).

  10. Investigation on the variation of annual ring thicknesses and word densities in South African Pinus radiata stands under the influence of climate and different thinning measures by means of radiodensitometry

    International Nuclear Information System (INIS)

    Bues, C.T.

    1984-01-01

    The present work investigates three phenomena of growth biology in Pinus radiata stands: In the first investigation project: the thickness of the annual rings in relation to climate factors; In the second project: the variability of annual ring thickness and wood density as a function of different thinning measures; In the third project the variability of wood density within a Pinus radiate stand is analyzed. To determine the thickness of the annual rings and the wood density values within the annual rings, the method of radiodensitometry, developed during the last decade, is adopted: In the first investigation project the thicknesses of 800 annual rings are determined, in the second project 3808 annual ring structures are investigated, and in the third project 2000 annual rings are evaluated for their density characteristics. (orig./MG) [de

  11. Calculus of variations

    CERN Document Server

    Gelfand, I M

    2000-01-01

    Based on a series of lectures given by I. M. Gelfand at Moscow State University, this book actually goes considerably beyond the material presented in the lectures. The aim is to give a treatment of the elements of the calculus of variations in a form both easily understandable and sufficiently modern. Considerable attention is devoted to physical applications of variational methods, e.g., canonical equations, variational principles of mechanics, and conservation laws.The reader who merely wishes to become familiar with the most basic concepts and methods of the calculus of variations need on

  12. Influence of Design Variations on Systems Performance

    Science.gov (United States)

    Tumer, Irem Y.; Stone, Robert B.; Huff, Edward M.; Norvig, Peter (Technical Monitor)

    2000-01-01

    High-risk aerospace components have to meet very stringent quality, performance, and safety requirements. Any source of variation is a concern, as it may result in scrap or rework. poor performance, and potentially unsafe flying conditions. The sources of variation during product development, including design, manufacturing, and assembly, and during operation are shown. Sources of static and dynamic variation during development need to be detected accurately in order to prevent failure when the components are placed in operation. The Systems' Health and Safety (SHAS) research at the NASA Ames Research Center addresses the problem of detecting and evaluating the statistical variation in helicopter transmissions. In this work, we focus on the variations caused by design, manufacturing, and assembly of these components, prior to being placed in operation (DMV). In particular, we aim to understand and represent the failure and variation information, and their correlation to performance and safety and feed this information back into the development cycle at an early stage. The feedback of such critical information will assure the development of more reliable components with less rework and scrap. Variations during design and manufacturing are a common source of concern in the development and production of such components. Accounting for these variations, especially those that have the potential to affect performance, is accomplished in a variety ways, including Taguchi methods, FMEA, quality control, statistical process control, and variation risk management. In this work, we start with the assumption that any of these variations can be represented mathematically, and accounted for by using analytical tools incorporating these mathematical representations. In this paper, we concentrate on variations that are introduced during design. Variations introduced during manufacturing are investigated in parallel work.

  13. Ensembl variation resources

    Directory of Open Access Journals (Sweden)

    Marin-Garcia Pablo

    2010-05-01

    Full Text Available Abstract Background The maturing field of genomics is rapidly increasing the number of sequenced genomes and producing more information from those previously sequenced. Much of this additional information is variation data derived from sampling multiple individuals of a given species with the goal of discovering new variants and characterising the population frequencies of the variants that are already known. These data have immense value for many studies, including those designed to understand evolution and connect genotype to phenotype. Maximising the utility of the data requires that it be stored in an accessible manner that facilitates the integration of variation data with other genome resources such as gene annotation and comparative genomics. Description The Ensembl project provides comprehensive and integrated variation resources for a wide variety of chordate genomes. This paper provides a detailed description of the sources of data and the methods for creating the Ensembl variation databases. It also explores the utility of the information by explaining the range of query options available, from using interactive web displays, to online data mining tools and connecting directly to the data servers programmatically. It gives a good overview of the variation resources and future plans for expanding the variation data within Ensembl. Conclusions Variation data is an important key to understanding the functional and phenotypic differences between individuals. The development of new sequencing and genotyping technologies is greatly increasing the amount of variation data known for almost all genomes. The Ensembl variation resources are integrated into the Ensembl genome browser and provide a comprehensive way to access this data in the context of a widely used genome bioinformatics system. All Ensembl data is freely available at http://www.ensembl.org and from the public MySQL database server at ensembldb.ensembl.org.

  14. Numerical integration of variational equations.

    Science.gov (United States)

    Skokos, Ch; Gerlach, E

    2010-09-01

    We present and compare different numerical schemes for the integration of the variational equations of autonomous Hamiltonian systems whose kinetic energy is quadratic in the generalized momenta and whose potential is a function of the generalized positions. We apply these techniques to Hamiltonian systems of various degrees of freedom and investigate their efficiency in accurately reproducing well-known properties of chaos indicators such as the Lyapunov characteristic exponents and the generalized alignment indices. We find that the best numerical performance is exhibited by the "tangent map method," a scheme based on symplectic integration techniques which proves to be optimal in speed and accuracy. According to this method, a symplectic integrator is used to approximate the solution of the Hamilton equations of motion by the repeated action of a symplectic map S , while the corresponding tangent map TS is used for the integration of the variational equations. A simple and systematic technique to construct TS is also presented.

  15. Variational Transition State Theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  16. Short-term variations of radiocarbon during the last century

    International Nuclear Information System (INIS)

    Burchuladze, A.A.; Pagava, S.V.; Jurina, V.; Povinec, P.; Usacev, S.

    1982-01-01

    Radiocarbon variations related to the 11-year solar cycle during the last century are discussed. Previous investigations on short term 14 C variations in tree rings are compared with 14 C measurements in Georgian wine samples. The amplitude of 14 C variations as obtained by various authors ranges from 0.2 to about 1%. (author)

  17. Variational principles in physics

    CERN Document Server

    Basdevant, Jean-Louis

    2007-01-01

    Optimization under constraints is an essential part of everyday life. Indeed, we routinely solve problems by striking a balance between contradictory interests, individual desires and material contingencies. This notion of equilibrium was dear to thinkers of the enlightenment, as illustrated by Montesquieu’s famous formulation: "In all magistracies, the greatness of the power must be compensated by the brevity of the duration." Astonishingly, natural laws are guided by a similar principle. Variational principles have proven to be surprisingly fertile. For example, Fermat used variational methods to demonstrate that light follows the fastest route from one point to another, an idea which came to be known as Fermat’s principle, a cornerstone of geometrical optics. Variational Principles in Physics explains variational principles and charts their use throughout modern physics. The heart of the book is devoted to the analytical mechanics of Lagrange and Hamilton, the basic tools of any physicist. Prof. Basdev...

  18. Variational Monte Carlo Technique

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 8. Variational Monte Carlo Technique: Ground State Energies of Quantum Mechanical Systems. Sukanta Deb. General Article Volume 19 Issue 8 August 2014 pp 713-739 ...

  19. Generalized quasi variational inequalities

    Energy Technology Data Exchange (ETDEWEB)

    Noor, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

    1996-12-31

    In this paper, we establish the equivalence between the generalized quasi variational inequalities and the generalized implicit Wiener-Hopf equations using essentially the projection technique. This equivalence is used to suggest and analyze a number of new iterative algorithms for solving generalized quasi variational inequalities and the related complementarity problems. The convergence criteria is also considered. The results proved in this paper represent a significant improvement and refinement of the previously known results.

  20. Germanic Verb Particle Variation

    DEFF Research Database (Denmark)

    Vikner, Sten

    2017-01-01

    This paper has two closely related goals. The more "global" one is to present an overview of the variation conceming verb particles across the Germanic languages (see e.g. den Dikken 1995; Haiden 2005; Mclntyre 2007 and many others), and the more "local" one is to use some of this variation data...... to argue for Yiddish being an SOV-language like German and Dutch rather than an SVO-language like English and the Scandinavian languages....

  1. Variational Bayesian Filtering

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav; Quinn, A.

    2008-01-01

    Roč. 56, č. 10 (2008), s. 5020-5030 ISSN 1053-587X R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bayesian filtering * particle filtering * Variational Bayes Subject RIV: BC - Control Systems Theory Impact factor: 2.335, year: 2008 http://library.utia.cas.cz/separaty/2008/AS/smidl-variational bayesian filtering.pdf

  2. Variational Neural Machine Translation

    OpenAIRE

    Zhang, Biao; Xiong, Deyi; Su, Jinsong; Duan, Hong; Zhang, Min

    2016-01-01

    Models of neural machine translation are often from a discriminative family of encoderdecoders that learn a conditional distribution of a target sentence given a source sentence. In this paper, we propose a variational model to learn this conditional distribution for neural machine translation: a variational encoderdecoder model that can be trained end-to-end. Different from the vanilla encoder-decoder model that generates target translations from hidden representations of source sentences al...

  3. Sequences for Student Investigation

    Science.gov (United States)

    Barton, Jeffrey; Feil, David; Lartigue, David; Mullins, Bernadette

    2004-01-01

    We describe two classes of sequences that give rise to accessible problems for undergraduate research. These problems may be understood with virtually no prerequisites and are well suited for computer-aided investigation. The first sequence is a variation of one introduced by Stephen Wolfram in connection with his study of cellular automata. The…

  4. Variation as a main feature of norm

    Directory of Open Access Journals (Sweden)

    S. Poladova

    2017-09-01

    Full Text Available The past half-century has witnessed remarkable growth in the study of language variation, and it has now become a highly productive subfield of research in sociolinguistics. Variability is everywhere in language, from the unique details in each production of a sound or sign to the auditory or visual processing of the linguistic signal. All languages that we can observe today show variation; what is more, they vary in identical ways, namely geographically and socially. It’s no secret that languages like English are full of variation. So, the aim of the article is to detect the reasons of variation and to uncover rates of usage of different free variations for a given set of lexical items. The research work is carried out by using the descriptive, comparative methods by subjecting to analysis the specific language materials. The discovery of law of variation became a starting point for the evolution of linguistics. The problem of search of variation facts and its role in the functioning of language system concerns many specialists from the outset. The scope of the investigation was to set up a system out of chaos of phenomena. Currently, the fact of conditionality of variation by system relations existing in the language is considered to be established.

  5. Exploring subdomain variation in biomedical language

    Directory of Open Access Journals (Sweden)

    Séaghdha Diarmuid Ó

    2011-05-01

    Full Text Available Abstract Background Applications of Natural Language Processing (NLP technology to biomedical texts have generated significant interest in recent years. In this paper we identify and investigate the phenomenon of linguistic subdomain variation within the biomedical domain, i.e., the extent to which different subject areas of biomedicine are characterised by different linguistic behaviour. While variation at a coarser domain level such as between newswire and biomedical text is well-studied and known to affect the portability of NLP systems, we are the first to conduct an extensive investigation into more fine-grained levels of variation. Results Using the large OpenPMC text corpus, which spans the many subdomains of biomedicine, we investigate variation across a number of lexical, syntactic, semantic and discourse-related dimensions. These dimensions are chosen for their relevance to the performance of NLP systems. We use clustering techniques to analyse commonalities and distinctions among the subdomains. Conclusions We find that while patterns of inter-subdomain variation differ somewhat from one feature set to another, robust clusters can be identified that correspond to intuitive distinctions such as that between clinical and laboratory subjects. In particular, subdomains relating to genetics and molecular biology, which are the most common sources of material for training and evaluating biomedical NLP tools, are not representative of all biomedical subdomains. We conclude that an awareness of subdomain variation is important when considering the practical use of language processing applications by biomedical researchers.

  6. Ladder Variational Autoencoder

    DEFF Research Database (Denmark)

    Sønderby, Casper Kaae; Raiko, Tapani; Maaløe, Lars

    2016-01-01

    Variational autoencoders are powerful models for unsupervised learning. However deep models with several layers of dependent stochastic variables are difficult to train which limits the improvements obtained using these highly expressive models. We propose a new inference model, the Ladder...... Variational Autoencoder, that recursively corrects the generative distribution by a data dependent approximate likelihood in a process resembling the recently proposed Ladder Network. We show that this model provides state of the art predictive log-likelihood and tighter log-likelihood lower bound compared...... to the purely bottom-up inference in layered Variational Autoencoders and other generative models. We provide a detailed analysis of the learned hierarchical latent representation and show that our new inference model is qualitatively different and utilizes a deeper more distributed hierarchy of latent...

  7. Ladder variational autoencoders

    DEFF Research Database (Denmark)

    Sønderby, Casper Kaae; Raiko, Tapani; Maaløe, Lars

    2016-01-01

    Variational autoencoders are powerful models for unsupervised learning. However deep models with several layers of dependent stochastic variables are difficult to train which limits the improvements obtained using these highly expressive models. We propose a new inference model, the Ladder...... Variational Autoencoder, that recursively corrects the generative distribution by a data dependent approximate likelihood in a process resembling the recently proposed Ladder Network. We show that this model provides state of the art predictive log-likelihood and tighter log-likelihood lower bound compared...... to the purely bottom-up inference in layered Variational Autoencoders and other generative models. We provide a detailed analysis of the learned hierarchical latent representation and show that our new inference model is qualitatively different and utilizes a deeper more distributed hierarchy of latent...

  8. Fimbrial phase variation

    DEFF Research Database (Denmark)

    Khandige, Surabhi; Møller-Jensen, Jakob

    2016-01-01

    Surface fimbriae of pathogenic Escherichia coli facilitate sensing, adhesion and even invasion of host epithelial cells. While it is known that the pathogen has the potential to express a plethora of fimbrial variants susceptible to rapid phase ON/OFF variation, it is an open question...... if the fimbrial diversity seen at the population level is the product of random stochasticity or a concerted effort based on active communication. Here we discuss the possibility of a mechanism alternative to a stochastic fimbrial phase variation model affecting the dynamics of a heterogeneous population....

  9. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  10. an investigation into the applicability of natural load variation ...

    African Journals Online (AJOL)

    Rev. Anoliefo

    Currently, photvoltaic (PV) modules are characterized based on open circuit voltage, short circuit current as well as voltage and current at ... By looping through the resistors in parallel, the firmware matches load impedance to the impedance of the ..... while series resistance tended to decrease with decrease in irradiance.

  11. Investigation of Seasonal Variation of groundwater Quality in Jimeta ...

    African Journals Online (AJOL)

    Sadiq

    GLOBAL JOURNAL OF GEOLOGICAL SCIENCES VOL, 10, NO.1, 2012 15-36 ... chloride exceeded the recommended standards of drinking water quality in the rainy season from the shallow and ... chloride, and decrease in ammonium ion and coliform with water depth in shallow aquifer in the dry season, and COD, nitrate ...

  12. Getting the Argument Started: A Variation on the Density Investigation

    Science.gov (United States)

    Walker, Joi P.; Wolf, Steven F.

    2017-01-01

    The ability to "engage in argument from evidence" is one of the eight practices identified in the "Next Generation Science Standards" as well as an emerging focus of undergraduate chemistry curricula. Guiding students to make evidence-based claims that engender argumentation will require faculty to revise conventional…

  13. Investigation of W/O microemulsion droplets by contrast variation ...

    Indian Academy of Sciences (India)

    Dynamic and static light scattering experiments have been performed at various molar ratios () of water to AOT and temperatures on water-in-oil (W/O) microemulsions dispersed in n-heptane, n-octane, and n-nonane. Size and shape fluctuations of microemulsion droplets are determined with very high precision because ...

  14. Transducer frequency response variations investigated by time reversal calibration

    Czech Academy of Sciences Publication Activity Database

    Kober, Jan; Převorovský, Zdeněk

    2016-01-01

    Roč. 26, č. 2 (2016), A16-A16 ISSN 1213-3825. [Europen Conference on Acoustic Emission Testing /32./. 07.09.2016-09.09.2016, Praha] Institutional support: RVO:61388998 Keywords : calibration * time reversal * transducer * frequency response Subject RIV: BI - Acoustic s

  15. Predicting stretcher carriage: Investigating variations in bilateral carry tests.

    Science.gov (United States)

    Beck, Ben; Middleton, Kane J; Carstairs, Greg L; Billing, Daniel C; Caldwell, Joanne N

    2016-07-01

    Carrying a casualty on a stretcher is a critical task within military and emergency service occupations. This study evaluated the impact of manipulating carry speed and the object type in bilateral carries on the ability to predict performance and reflect the physical and physiological requirements of a unilateral stretcher carry. We demonstrated that three task-related predictive tests; a jerry can carry performed at 4.5 km h(-1)or 5.0 km h(-1) and a kettle-bell carry performed at 5.0 km h(-1) were strongly predictive of the physical and physiological demands of an individual participating as part of a four-person stretcher carry team. Therefore, bilateral predictive assessments have the utility for predicting the suitability of employees to effectively and safely conduct a four-person unilateral stretcher carry. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  16. Vowel variation in Southern Sotho: an acoustic investigation

    CSIR Research Space (South Africa)

    Barnard, E

    2008-01-01

    Full Text Available , the current study is a first step in the direction of providing such information. Measurements of the frequencies of the first two formants of the vowels represented by the orthographic symbols i e a o u are made in several contexts in order to motivate...

  17. Investigation of W/O microemulsion droplets by contrast variation ...

    Indian Academy of Sciences (India)

    The estimated extent of polydispersity index of 17% is found, whereas the ... It is therefore possible to combine water and AOT in such proportions that the average dielectric constant of water plus AOT is the same as that of the n-alkane ..... [6] E B Leodidis, T A Hatton in Structure and reactivity of reverse micelles edited by.

  18. Investigation of W/O microemulsion droplets by contrast variation ...

    Indian Academy of Sciences (India)

    various molar ratios (µ) of water to AOT and temperatures on water-in-oil (W/O) mi- croemulsions dispersed in n-heptane, ... tures composed of surfactant, water, and oil have attracted much interest since they form thermodynamically stable phases .... filter into dust-free sample cells. The cylindrical sample cells are made of ...

  19. Investigation of seasonal variation of groundwater quality in Jimeta ...

    African Journals Online (AJOL)

    The contaminants in all the aquifers revealed strong positive correlations in both seasons which are an indication of common source. Factor analysis indicates that groundwater chemistry is controlled by anthropogenic activities, salinity, ammonification and natural mineralization. It is recommended that safe waste disposal ...

  20. Fluency Variation in Adolescents

    Science.gov (United States)

    De Andrade, Claudia Regina Furquim; Martins, Vanessa De Oliveira

    2007-01-01

    The Speech Fluency Profile of fluent adolescent speakers of Brazilian Portuguese, were examined with respect to gender and neurolinguistic variations. Speech samples of 130 male and female adolescents, aged between 12;0 and 17;11 years were gathered. They were analysed according to type of speech disruption; speech rate; and frequency of speech…

  1. Generalized Variational Inequalities

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Laurencot, P.

    2002-01-01

    Roč. 9, č. 1 (2002), s. 159-183 ISSN 0944-6532 Institutional research plan: CEZ:AV0Z1019905 Keywords : hysteresis%evolution variational inequality%Young integral Subject RIV: BA - General Mathematics Impact factor: 0.145, year: 2002

  2. The variational spiked oscillator

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Ullah, N.

    1992-08-01

    A variational analysis of the spiked harmonic oscillator Hamiltonian -d 2 / d x 2 + x 2 + δ/ x 5/2 , δ > 0, is reported in this work. A trial function satisfying Dirichlet boundary conditions is suggested. The results are excellent for a large range of values of the coupling parameter. (author)

  3. A variational approach

    Indian Academy of Sciences (India)

    We study the optical switching of the two-dimensional nonlinear coupler in a doped photopolymer. The coupled ... Optical switching; variational approach; Jacobi's elliptic function; surface plasmon resonance ..... [4] G P Agrawal, Applications of nonlinear fiber optics (Academic Press, New York,. 2006). [5] R G Hunsperger ...

  4. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  5. Variation in decision making

    NARCIS (Netherlands)

    Dall, Sasha R. X.; Gosling, Samuel; Gordon D.A., Brown,; Dingemanse, Niels; Ido, Erev,; Martin, Kocher,; Laura, Schulz,; Todd, Peter M; Weissing, Franz; Wolf, Max; Hammerstein, Peter; Stevens, Jeffrey R.

    2012-01-01

    Variation in how organisms allocate their behavior over their lifetimes is key to determining Darwinian fitness., and thus the evolution of human and nonhuman decision making. This chapter explores how decision making varies across biologically and societally significant scales and what role such

  6. On exterior variational calculus

    International Nuclear Information System (INIS)

    Aldrovandi, R.; Kraenkel, R.A.

    1987-01-01

    Exterior variational calculus is introduced through examples in field theory. It provides a very simple technique to decide on the existence of Lagrangians for given equations of motions and, in the case, to find them. Only local aspects are discussed but the analogy to exterior calculus on finite dimensional manifolds is complete, strongly suggesting its suitability to the study of topological aspects. (Author) [pt

  7. Intronic variation at the

    NARCIS (Netherlands)

    Trimbos, K.B.; Kentie, R.; van der Velde, M.; Hooijmeijer, J.C.E.W.; Poley, C.; Musters, C.J.M.; de Snoo, G.R.; Piersma, T.

    2013-01-01

    Recently, Schroeder etal. (2010, Ibis 152: 368-377) suggested that intronic variation in the CHD1-Z gene of Black-tailed Godwits breeding in southwest Friesland, The Netherlands, correlated with fitness components. Here we re-examine this surprising result using an expanded dataset (2088 birds

  8. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  9. Variational transition state theory

    International Nuclear Information System (INIS)

    Truhlar, D.G.

    1986-01-01

    This project is concerned with the development and applications of generalized transition state theory and multidimensional tunneling approximations to chemical reaction rates. They have developed and implemented several practical versions of variational transition state theory (VTST), namely canonical variational theory (CVT), improved canonical variational theory (ICVT), and microcanonical variational theory (μVT). They have also developed and implemented several accurate multidimensional semiclassical tunneling approximations, the most accurate of which are the small-curvature semiclassical adiabatic (SCSA), large-curvature version-3 (LC3), and least-action (LA) approximations. They have applied the methods to thermal rate constants, using transmission coefficients based on ground-state tunneling, and they have also presented and applied adiabatic and diabatic extensions to calculated rate constants for vibrationally excited reactants. Their general goal is to develop accurate methods for calculating chemical reaction rate constants that remain practical even for reasonably complicated molecules. The approximations mentioned above yield rate constants for systems whose potential energy surface is known or assumed. Thus a second, equally important aspect of their work is the determination or modeling, semi-empirically and/or from electronic structure calculations, of potential energy surfaces

  10. Measuring Linguistic Variation Commensurably

    NARCIS (Netherlands)

    Wieling, M.; Nerbonne, J.

    2011-01-01

    The primary data on pronunciation variation — e.g., dialect atlas data — is often recorded incommensurably, i.e. in different ways in different atlases, and even in different ways within the same atlas when teams of fieldworkers and transcribers are involved. In particular these data collections

  11. Variational transition state theory

    Energy Technology Data Exchange (ETDEWEB)

    Truhlar, D.G. [Univ. of Minnesota, Minneapolis (United States)

    1993-12-01

    This research program involves the development of variational transition state theory (VTST) and semiclassical tunneling methods for the calculation of gas-phase reaction rates and selected applications. The applications are selected for their fundamental interest and/or their relevance to combustion.

  12. Variation tolerant SoC design

    Science.gov (United States)

    Kozhikkottu, Vivek J.

    allocation of shared system resources as a means to combat the adverse impact of within-die variations on multi-core platforms. For multi-threaded programs executing on variation-impacted multi-cores platforms, we make the key observation that thread performance is not only a function of the frequency of the core on which it is executing on, but also depends upon the amount of shared system resources allocated to it. We utilize this insight to design a variation-aware runtime scheme which allocates the ways of a last-level shared L2 cache amongst the different cores/threads of a multi-core platform taking into account both application characteristics as well as chip specific variation profiles. Our experiments on 100 quad-core chips, each with a distinct variation profile, shows on an average 15% performance improvements for a suite of multi-threaded benchmarks. Our final contribution investigates the variation-tolerant design of domain-specific accelerators and demonstrates how the unique architectural properties of these accelerators can be leveraged to create highly effective variation tolerance mechanisms. We explore this concept through the variation-tolerant design of a vector processor that efficiently executes applications from the domains of recognition, mining and synthesis (RMS). We develop a novel design approach for variation tolerance, which leverages the unique nature of the vector reduction operations performed by this processor to effectively predict and preempt the occurrence of timing errors under variations and subsequently restore the correct output at the end of each vector reduction operation. We implement the above predict, preempt and restore operations by suitably enhancing the processor hardware and the application software and demonstrate considerable energy benefits (on an average 32%) across six applications from the domains of RMS. In conclusion, our work provides system designers with powerful tools and mechanisms in their efforts to combat

  13. Cosmic ray charged component variations at sea level

    Science.gov (United States)

    Charakhchyan, T. N.; Okhlopkov, V. P.; Krasotkin, A. F.; Svirzhevskij, N. S.; Charakhchyan, L. A.

    Results of measuring the cosmic ray charged component using devices installed at the Olen'ya station (the Murmansk region), in Dolgoprudny town (the Moscow region), and in Mirny (Antarctic continent) are investigated. The analysis has shown that apart from solar origin and seasonal variations there are annual variations of cosmic ray charged component. By results of comparing annual variations of the charged component on the Earth surface to data of neutron and muon components a conclusion is made that annual variations of the charge component on the Earth surface appear to be a manifestation of cosmic ray zonal modulation and are not connected with variations of galactic cosmic rays.

  14. Diurnal variations of Titan's ionosphere

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

    2009-06-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

  15. Conformable variational iteration method

    Directory of Open Access Journals (Sweden)

    Omer Acan

    2017-02-01

    Full Text Available In this study, we introduce the conformable variational iteration method based on new defined fractional derivative called conformable fractional derivative. This new method is applied two fractional order ordinary differential equations. To see how the solutions of this method, linear homogeneous and non-linear non-homogeneous fractional ordinary differential equations are selected. Obtained results are compared the exact solutions and their graphics are plotted to demonstrate efficiency and accuracy of the method.

  16. Canonical variate regression.

    Science.gov (United States)

    Luo, Chongliang; Liu, Jin; Dey, Dipak K; Chen, Kun

    2016-07-01

    In many fields, multi-view datasets, measuring multiple distinct but interrelated sets of characteristics on the same set of subjects, together with data on certain outcomes or phenotypes, are routinely collected. The objective in such a problem is often two-fold: both to explore the association structures of multiple sets of measurements and to develop a parsimonious model for predicting the future outcomes. We study a unified canonical variate regression framework to tackle the two problems simultaneously. The proposed criterion integrates multiple canonical correlation analysis with predictive modeling, balancing between the association strength of the canonical variates and their joint predictive power on the outcomes. Moreover, the proposed criterion seeks multiple sets of canonical variates simultaneously to enable the examination of their joint effects on the outcomes, and is able to handle multivariate and non-Gaussian outcomes. An efficient algorithm based on variable splitting and Lagrangian multipliers is proposed. Simulation studies show the superior performance of the proposed approach. We demonstrate the effectiveness of the proposed approach in an [Formula: see text] intercross mice study and an alcohol dependence study. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Somaclonal variation in rice

    International Nuclear Information System (INIS)

    Kucherenko, L.

    1990-01-01

    Full text: 32 varieties of Oryza sativa L. ssp. japonica were used as donors for callus induction from somatic tissues. In some cases, the callus was treated before regeneration with the chemical mutagen MNU. Some of the regenerated plants demonstrated heritable alterations, among them chlorophyll deficiencies, variation in plant height, awness, glume colouring and fertility. Along with these, a number of lines with agronomically valuable alterations concerning maturity time, panicle structure, plant productivity and grain quality were found. The spectrum of variability was very wide. Vivipary was noticed. Superdwarfs with plant height of about 15 cm were found. Plants with no visible distinctions could be variants too, for example, with increased protein content or disease resistance. The rate and the spectrum of the somaclonal variation were not influenced by the culture media but depended on the donor's genotype. On the basis of somaclonal variation a variety 'Bioryza' was developed. It is an early maturing (about 95-100 days), long grain variety, with grain yield up to 8 t/ha. (author)

  18. seasonal variation in chromium hexavalent and copper ...

    African Journals Online (AJOL)

    Admin

    GLOBAL JOURNAL OF GEOLOGICAL SCIENCES VOL 8, NO. 2, 2010: 143- ... Seasonal variation in heavy metal contamination of groundwater in the Jimeta- Yola area was investigated. The objectives ... and anthropogenic input is the only source influencing the contamination indices in the case of chromium hexavalent.

  19. Numerical Taxonomy and Morphological Variation of Cultivated ...

    African Journals Online (AJOL)

    A numerical taxonomic study was conducted to investigate the patterns of morphological and phenological variations in 45 okra accessions from different agroecological zones of Ghana dur-ing the rainy season of 2005. The results of the study showed that there were two main phenetic groupings of okra accessions in ...

  20. SEASONAL VARIATIONS IN GROUNDWATER QUALITY OF ...

    African Journals Online (AJOL)

    2015-02-05

    Feb 5, 2015 ... investigation is focused on seasonal variation in groundwater quality of Valsad district of south Gujarat (India). Groundwater ... natural resource that has to be conserved and preserved for sustenance of life in future [1]. Groundwater was ... The groundwater quality may also vary with seasonal changes [2].

  1. On polar daily geomagnetic variation

    Directory of Open Access Journals (Sweden)

    Paola De Michelis

    2015-11-01

    Full Text Available The aim of this work is to investigate the nature of the daily magnetic field perturbations produced by ionospheric and magnetospheric currents at high latitudes. We analyse the hourly means of the X and Y geomagnetic field components recorded by a meridian chain of permanent geomagnetic observatories in the polar region of the Northern Hemisphere during a period of four years (1995-1998 around the solar minimum. We apply a mathematical method, known as natural orthogonal component (NOC, which is capable of characterizing the dominant modes of the geomagnetic field daily variability through a set of empirical orthogonal functions (EOFs. Using the first two modes we reconstruct a two-dimensional equivalent current representation of the ionospheric electric currents, which contribute substantially to the geomagnetic daily variations. The obtained current structures resemble the equivalent current patterns of DP2 and DP1. We characterize these currents by studying their evolution with the geomagnetic activity level and by analysing their dependence on the interplanetary magnetic field. The obtained results support the idea of a coexistence of two main processes during all analysed period although one of them, the directly driven process, represents the dominant component of the geomagnetic daily variation.

  2. Biological variation of cystatin C

    DEFF Research Database (Denmark)

    Reinhard, Mark; Erlandsen, Erland; Randers, Else

    2009-01-01

    Introduction: Cystatin C has been investigated as a marker of the glomerular filtration rate. However, previous studies have reported conflicting results concerning the biological variation of cystatin C. The aim of the present study was to evaluate the biological variation of cystatin C...... available for analysis. Serum cystatin C was measured using Dade Behring N Latex Cystatin C assay and serum creatinine by an enzymatic method (Roche). Results: The mean serum concentration of cystatin C was 0.70 mg/l (range 0.44-1.09) and the mean serum creatinine was 77 µmol/l (range 54......-100). The analytical variance (CVA) was 2.0% for cystatin C and 1.6% for creatinine. The intra-individual variance (CVI) was greater for cystatin C than for creatinine (8.6% vs. 4.7%). The inter-individual variance (CVG) was similar for both analytes (cystatin C 15.1% vs. creatinine 14.4%). Accordingly, the index...

  3. Nursing care on admission and stay of the newborn in the accommodation set on intra-hospital

    Directory of Open Access Journals (Sweden)

    Paolla Amorim Malheiros Dulfe

    2015-04-01

    Full Text Available Objetivo: analisar os cuidados de enfermagem instituídos aos recém-nascidos em alojamento conjunto que, posteriormente, passaram por transferência intra-hospitalar. Métodos: pesquisa descritiva, exploratória, quanti-qualitativa, aprovada pelo Comitê de Ética em Pesquisa da Faculdade de Medicina do Hospital Universitário Antônio Pedro (HUAP, sob protocolo nº: 182.253/2012; e realizada com oitos enfermeiros do alojamento conjunto, mediante análise documental através de levantamento no banco dos prontuários com aplicação de um check list sobre a linha de cuidados de enfermagem e entrevista semiestruturada. Resultados: na analise dos dados, os resultados mostraram a importância da mulher e do recém-nascido no mesmo espaço, orientações aos acompanhantes. A realização do exame físico mostra a sua eficácia no seu acompanhamento. Conclusão: assim, o enfermeiro deve executar o seu cuidado na admissão e permanência do recém-nascido em sua integralidade, favorecendo o conforto e a segurança. Descritores: Enfermagem, Cuidados de enfermagem, Alojamento conjunto.

  4. Evaluation of natural language processing from emergency department computerized medical records for intra-hospital syndromic surveillance

    Directory of Open Access Journals (Sweden)

    Pagliaroli Véronique

    2011-07-01

    Full Text Available Abstract Background The identification of patients who pose an epidemic hazard when they are admitted to a health facility plays a role in preventing the risk of hospital acquired infection. An automated clinical decision support system to detect suspected cases, based on the principle of syndromic surveillance, is being developed at the University of Lyon's Hôpital de la Croix-Rousse. This tool will analyse structured data and narrative reports from computerized emergency department (ED medical records. The first step consists of developing an application (UrgIndex which automatically extracts and encodes information found in narrative reports. The purpose of the present article is to describe and evaluate this natural language processing system. Methods Narrative reports have to be pre-processed before utilizing the French-language medical multi-terminology indexer (ECMT for standardized encoding. UrgIndex identifies and excludes syntagmas containing a negation and replaces non-standard terms (abbreviations, acronyms, spelling errors.... Then, the phrases are sent to the ECMT through an Internet connection. The indexer's reply, based on Extensible Markup Language, returns codes and literals corresponding to the concepts found in phrases. UrgIndex filters codes corresponding to suspected infections. Recall is defined as the number of relevant processed medical concepts divided by the number of concepts evaluated (coded manually by the medical epidemiologist. Precision is defined as the number of relevant processed concepts divided by the number of concepts proposed by UrgIndex. Recall and precision were assessed for respiratory and cutaneous syndromes. Results Evaluation of 1,674 processed medical concepts contained in 100 ED medical records (50 for respiratory syndromes and 50 for cutaneous syndromes showed an overall recall of 85.8% (95% CI: 84.1-87.3. Recall varied from 84.5% for respiratory syndromes to 87.0% for cutaneous syndromes. The most frequent cause of lack of processing was non-recognition of the term by UrgIndex (9.7%. Overall precision was 79.1% (95% CI: 77.3-80.8. It varied from 81.4% for respiratory syndromes to 77.0% for cutaneous syndromes. Conclusions This study demonstrates the feasibility of and interest in developing an automated method for extracting and encoding medical concepts from ED narrative reports, the first step required for the detection of potentially infectious patients at epidemic risk.

  5. Equilibrium models and variational inequalities

    CERN Document Server

    Konnov, Igor

    2007-01-01

    The concept of equilibrium plays a central role in various applied sciences, such as physics (especially, mechanics), economics, engineering, transportation, sociology, chemistry, biology and other fields. If one can formulate the equilibrium problem in the form of a mathematical model, solutions of the corresponding problem can be used for forecasting the future behavior of very complex systems and, also, for correcting the the current state of the system under control. This book presents a unifying look on different equilibrium concepts in economics, including several models from related sciences.- Presents a unifying look on different equilibrium concepts and also the present state of investigations in this field- Describes static and dynamic input-output models, Walras, Cassel-Wald, spatial price, auction market, oligopolistic equilibrium models, transportation and migration equilibrium models- Covers the basics of theory and solution methods both for the complementarity and variational inequality probl...

  6. Investigative psychology

    OpenAIRE

    Canter, David V.

    2010-01-01

    The domain of Investigative Psychology covers all aspects of psychology that are relevant to the conduct of criminal or civil investigations. Its focus is on the ways in which criminal activities may be examined and understood in order for the detection of crime to be effective and legal proceedings to be appropriate. As such Investigative Psychology is concerned with psychological input to the full range of issues that relate to the management, investigation and prosecution of crime

  7. Variation, structure and norms

    DEFF Research Database (Denmark)

    Harder, Peter

    2014-01-01

    After a period when the focus was essentially on mental architecture, the cognitive sciences are increasingly integrating the social dimension. The rise of a cognitive sociolinguistics is part of this trend. The article argues that this process requires a re-evaluation of some entrenched positions...... in linguistics: those that see linguistic norms as antithetical to a descriptive and variational linguistics. Once such a re-evaluation has taken place, however, the social recontextualization of cognition will enable linguistics (including sociolinguistics as an integral part), to eliminate the cracks...

  8. Damage Localization of an Offshore Platform considering Temperature Variations

    Directory of Open Access Journals (Sweden)

    Shuqing Wang

    2015-01-01

    Full Text Available Modal parameters are sensitive indicators of structural damages. However, these modal parameters are sensitive not only to damage, but also to the environmental variations. Development of vibration based damage detection methodology which is robust to environmental variation is essentially important for the structural safety. The present paper utilizes a recently developed modal strain energy decomposition (MSED method to localize the damage of an offshore structure. A progress of the present paper is to take the temperature variation into consideration and Monte Carlo simulation is introduced to investigate the effect of temperature variation on the robustness of damage localization. Numerical study is conducted on an offshore platform structure considering the temperature variation. Several damage cases, including single and double damage scenarios, are included to investigate the damage localization algorithm. Results indicate that the MSED algorithm is able to detect the damage despite the temperature variations.

  9. Introduction to global variational geometry

    CERN Document Server

    Krupka, Demeter

    2015-01-01

    The book is devoted to recent research in the global variational theory on smooth manifolds. Its main objective is an extension of the classical variational calculus on Euclidean spaces to (topologically nontrivial) finite-dimensional smooth manifolds; to this purpose the methods of global analysis of differential forms are used. Emphasis is placed on the foundations of the theory of variational functionals on fibered manifolds - relevant geometric structures for variational principles in geometry, physical field theory and higher-order fibered mechanics. The book chapters include: - foundations of jet bundles and analysis of differential forms and vector fields on jet bundles, - the theory of higher-order integral variational functionals for sections of a fibred space, the (global) first variational formula in infinitesimal and integral forms- extremal conditions and the discussion of Noether symmetries and generalizations,- the inverse problems of the calculus of variations of Helmholtz type- variational se...

  10. Gauging Variational Inference

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahn, Sungsoo [Korea Advanced Inst. Science and Technology (KAIST), Daejeon (Korea, Republic of); Shin, Jinwoo [Korea Advanced Inst. Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2017-05-25

    Computing partition function is the most important statistical inference task arising in applications of Graphical Models (GM). Since it is computationally intractable, approximate methods have been used to resolve the issue in practice, where meanfield (MF) and belief propagation (BP) are arguably the most popular and successful approaches of a variational type. In this paper, we propose two new variational schemes, coined Gauged-MF (G-MF) and Gauged-BP (G-BP), improving MF and BP, respectively. Both provide lower bounds for the partition function by utilizing the so-called gauge transformation which modifies factors of GM while keeping the partition function invariant. Moreover, we prove that both G-MF and G-BP are exact for GMs with a single loop of a special structure, even though the bare MF and BP perform badly in this case. Our extensive experiments, on complete GMs of relatively small size and on large GM (up-to 300 variables) confirm that the newly proposed algorithms outperform and generalize MF and BP.

  11. Harmonically excited orbital variations

    International Nuclear Information System (INIS)

    Morgan, T.

    1985-01-01

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs

  12. Variations in brain DNA

    Directory of Open Access Journals (Sweden)

    Jesus eAvila

    2014-11-01

    Full Text Available It is assumed that DNA sequences are conserved in the diverse cell types present in a multicellular organism like the human being. Thus, in order to compare the sequences in the genome of DNA from different individuals, nucleic acid is commonly isolated from a single tissue. In this regard, blood cells are widely used for this purpose because of their availability. Thus blood DNA has been used to study genetic familiar diseases that affect other tissues and organs, such as the liver, heart, and brain. While this approach is valid for the identification of familial diseases in which mutations are present in parental germinal cells and, therefore, in all the cells of a given organism, it is not suitable to identify sporadic diseases in which mutations might occur in specific somatic cells. This review addresses somatic DNA variations in different tissues or cells (mainly in the brain of single individuals and discusses whether the dogma of DNA invariance between cell types is indeed correct. We will also discuss how single nucleotide somatic variations arise, focusing on the presence of specific DNA mutations in the brain.

  13. Pulse pressure and diurnal blood pressure variation

    DEFF Research Database (Denmark)

    Knudsen, Søren Tang; Poulsen, Per Løgstrup; Hansen, Klavs Würgler

    2002-01-01

    BACKGROUND: In nondiabetic subjects pulse pressure (PP) is an independent predictor of cardiovascular disease and microalbuminuria. Reduced circadian blood pressure (BP) variation is a potential risk factor for the development of diabetic complications. We investigated the association between...... retinopathy, nephropathy, macrovascular disease, PP, and diurnal BP variation in a group of type 2 diabetic patients. METHODS: In 80 type 2 diabetic patients we performed 24-h ambulatory BP (AMBP) and fundus photographs. Urinary albumin excretion was evaluated by urinary albumin/creatinine ratio. Presence...... and 3-6 had higher PP and blunted diurnal BP variation: night PP 55 +/- 10 mm Hg, 64 +/- 10 mm Hg, 61 +/- 15 mm Hg, P groups (45 normo-, 19 micro-, and 15...

  14. Evaluation of variational approximations

    International Nuclear Information System (INIS)

    Trevisan, L.A.

    1991-01-01

    In Feynman's approach to quantum statistical mechanics, the partition function can e represented as a path integral. A recently proposed variation method of Feynman-Kleinert is able to transform the path integral into an integral in phase space, in which the quantum fluctuations have been taken care of by introducing the effective classical potential. This method has been testes with succeed for the smooth potentials and for the singular potential of delta. The method to the strong singular potentials is applied: a quadratic potential and a linear potential both with a rigid wall at the origin. By satisfying the condition that the density of the particle be vanish at the origin, and adapted method of Feynman-Kleinert in order to improve the method is introduced. (author)

  15. Monthly variations of the Caspian sea level and solar activity.

    Science.gov (United States)

    Romanchuk, P. R.; Pasechnik, M. N.

    The connection between 11-year cycle of solar activity and the Caspian sea level is investigated. Seasonal changes of the Caspian sea level and annual variations of the sea level with variations of solar activity are studied. The results of the verifications of the sea level forecasts obtained with application of the rules discovered by the authors are given.

  16. On the variational approach to axisymmetric magnetohydrodynamic equilibria

    International Nuclear Information System (INIS)

    Andreussi, T.; Pegoraro, F.

    2008-01-01

    The variational formulation of the axisymmetric magnetohydrodynamic equilibrium equations with plasma flows is addressed and a more comprehensive method is presented that allows, in particular, for open boundary conditions and discontinuous (shock) solutions. A numerical procedure based on the variational formulation is described and a validation test for an open conical geometry, including also hydrodynamic shocks, is investigated.

  17. Task demands and individual variation in referring expressions

    NARCIS (Netherlands)

    Baltaretu, Adriana-Alexandra; Castro Ferreira, Thiago

    Aiming to improve the human-likeness of natural language generation systems, this study investigates different sources of variation that might influence the production of referring expressions (REs), namely the effect of task demands and inter- intra- individual variation. We collected REs using a

  18. Geographic variation in the morphology, echolocation and diet of the ...

    African Journals Online (AJOL)

    The insectivorous bat Chaerephon pumilus has a wide distribution in Africa and displays considerable variation in the colour of its wings and venter.We investigated whether variation is also evident in its morphology, echolocation and diet by comparing a population of this species in Amani Nature Reserve, Tanzania, with ...

  19. Annual variation in the net longshore sediment transport rate

    CSIR Research Space (South Africa)

    Schoonees, JS

    2000-05-01

    Full Text Available The annual variation in the net long shore sediment transport rates at three South African and at one North African site is investigated. The net rates at these sites, given in the first table, showed large variations. It was found that measurements...

  20. Variational formulation based analysis on growth of yield front in ...

    African Journals Online (AJOL)

    The present study investigates the growth of elastic-plastic front in rotating solid disks of non-uniform thickness having exponential and parabolic geometry variation. The problem is solved through an extension of a variational method in elastoplastic regime. The formulation is based on von-Mises yield criterion and linear ...

  1. MtDNA T4216C variation in multiple sclerosis

    DEFF Research Database (Denmark)

    Andalib, Sasan; Emamhadi, Mohammadreza; Yousefzadeh-Chabok, Shahrokh

    2016-01-01

    MtDNA T4216C variation has frequently been investigated in Multiple Sclerosis (MS) patients; nonetheless, controversy has existed about the evidence of association of this variation with susceptibility to MS. The present systematic review and meta-analysis converge the results of the preceding...

  2. Role of Anatomic Variations of Paranasal Sinuses on the ...

    African Journals Online (AJOL)

    2017-05-09

    May 9, 2017 ... pathology. The coexistence of anatomic variations with sinusitis was statistically investigated.Results: At least one anatomical variation of paranasal sinuses was detected in 325 patients ... area, hardly evaluated regions of sinonasal pathologies ..... formation. Optic nerve and extraorbital muscle damage.

  3. Fire investigation

    Science.gov (United States)

    Gomberg, A.

    There was considerable progress made on several fronts of fire investigation in the United States in recent years. Progress was made in increasing the quantity of fire investigation and reporting, through efforts to develop the National Fire Incident Reporting System. Improving overall quality of fire investigation is the objective of efforts such as the Fire Investigation Handbook, which was developed and published by the National Bureau of Standards, and the upgrading and expanding of the ""dictionary'' of fire investigation and reporting, the NFPA 901, Uniform Coding for Fire Protection, system. The science of fire investigation as furthered also by new approaches to post fire interviews being developed at the University of Washington, and by in-depth research into factors involved in several large loss fires, including the MGM Grand Hotel in Las Vegas. Finally, the use of special study fire investigations - in-depth investigations concentrating on specific fire problems - is producing new glimpses into the nature of the national fire problem. A brief description of the status of efforts in each of these areas is discussed.

  4. Event Investigation

    International Nuclear Information System (INIS)

    Korosec, D.

    2000-01-01

    The events in the nuclear industry are investigated from the license point of view and from the regulatory side too. It is well known the importance of the event investigation. One of the main goals of such investigation is to prevent the circumstances leading to the event and the consequences of the event. The protection of the nuclear workers against nuclear hazard, and the protection of general public against dangerous effects of an event could be achieved by systematic approach to the event investigation. Both, the nuclear safety regulatory body and the licensee shall ensure that operational significant events are investigated in a systematic and technically sound manner to gather information pertaining to the probable causes of the event. One of the results should be appropriate feedback regarding the lessons of the experience to the regulatory body, nuclear industry and general public. In the present paper a general description of systematic approach to the event investigation is presented. The systematic approach to the event investigation works best where cooperation is present among the different divisions of the nuclear facility or regulatory body. By involving management and supervisors the safety office can usually improve their efforts in the whole process. The end result shall be a program which serves to prevent events and reduce the time and efforts solving the root cause which initiated each event. Selection of the proper method for the investigation and an adequate review of the findings and conclusions lead to the higher level of the overall nuclear safety. (author)

  5. Seismic noise level variation in South Korea

    Science.gov (United States)

    Sheen, D.; Shin, J.

    2008-12-01

    The variations of seismic background noise in South Korea have been investigated by means of power spectral analysis. The Korea Institute of Geoscience and Mineral Resources (KIGAM) and the Korea Meteorological Administation (KMA) have national wide seismic networks in South Korea, and, in the end of 2007, there are 30 broadband stations which have been operating for more than a year. In this study, we have estimated the power spectral density of seismic noise for 30 broadband stations from 2005 to 2007. Since we estimate PSDs from a large dataset of continuous waveform in this study, a robust PSD estimate of McNamara and Buland (2004) is used. In the frequency range 1-5 Hz, the diurnal variations of noise are observed at most of stations, which are especially larger at coastal stations and at insular than at inland. Some stations shows daily difference of diurnal variations, which represents that cultural activities contribute to the noise level of a station. The variation of number of triggered stations, however, shows that cultural noise has little influence on the detection capability of seismic network in South Korea. Seasonal variations are observed well in the range 0.1-0.5 Hz, while much less found in the frequency range 1-5 Hz. We observed that strong peaks in the range 0.1-0.5 Hz occur at the summer when Pacific typhoons are close to the Korean Peninsula.

  6. Dynamics of nonholonomic systems from variational principles embedded variation identity

    International Nuclear Information System (INIS)

    Guo Yongxin; Liu Shixing; Liu Chang; Chang Peng

    2009-01-01

    Nondeterminacy of dynamics, i.e., the nonholonomic or the vakonomic, fundamental variational principles, e.g., the Lagrange-d'Alembert or Hamiltonian, and variational operators, etc., of nonholonomic mechanical systems can be attributed to the non-uniqueness of ways how to realize nonholonomic constraints. Making use of a variation identity of nonholonomic constraints embedded into the Hamilton's principle with the method of Lagrange undetermined multipliers, three kinds of dynamics for the nonholonomic systems including the vakonomic and nonholonomic ones and a new one are obtained if the variation is respectively reduced to three conditional variations: vakonomic variation, Hoelder's variation and Suslov's variation, defined by the identity. Therefore, different dynamics of nonholonomic systems can be derived from an integral variational principle, utilizing one way of embedding constraints into the principle, with different variations. It is verified that the similar embedding of the identity into the Lagrange-d'Alembert principle gives rise to the nonholonomic dynamics but fails to give the vakonomic one unless the constraints are integrable.

  7. Legibility Investigations

    DEFF Research Database (Denmark)

    Beier, Sofie

    2013-01-01

    One frequent problem in legibility investigations is that the tested typefaces vary on too many variables. In an investigation which compares typefaces that – at the same time – vary on letter width, weight, contrast and skeleton, it will be difficult to determine precisely why the findings come....... One is the master typeface; three of the remaining typefaces have one stylistic feature that differs from the master (skeleton, weight, and width); and three have two stylistic features that differ from the master (weight/skeleton, weight/contrast and weight/width). In an experimental investigation...

  8. Clinical Investigations

    Science.gov (United States)

    1977-09-30

    Unit No. 77/20 (FY77, 0) An Analysis of Ameloblastic Fibro- odontoma ....................... 27 Department of Medicine Nork Unit No, 69/338 (FY69, T...Ar, Analysis of Ameiloblastic Fibro- odontoma ,IRK UNIT NO: 77/20 PRINCIPAL INVESTIGATOR: COL George J Tsagaris, DC ASSOCIATE INVESTIGATORS: OBJECTIVES...The coals of this research study are to report upon and analyze cases of ameloblastic fibro- odontoma and to correlate these findinas with those of

  9. Contour Stencils and Variational Image Processing

    Science.gov (United States)

    Getreuer, Pascal Tom

    The first part of this thesis is on contour stencils, a new method for edge adaptive image processing. We focus particularly on image zooming, which is the problem of increasing the resolution of a given image. An important aspect of zooming is accurate estimation of edge orientations. Contour stencils is a new method for estimating the image contours based on total variation along curves. Contour stencils are applied in designing several edge-adaptive color zooming methods. These zooming methods fall at different points in the balance between speed and quality. One of these zooming methods, contour stencil windowed zooming, is particular successful. Although most zooming methods require either solving a large linear system or running many iterations, this method has linear complexity in the number of pixels and can be computed in a single pass through the image. The zoomed image is constructed as a function that may be sampled anywhere, enabling arbitrary resampling operations. Comparisons show that contour stencil zooming methods are competitive with existing methods. Applications of contour stencils to corner detection and image enhancement are also illustrated. The second part of this thesis is on topics in variational image processing. First, we apply variational techniques to formulate a total variation optimal prediction in Harten multiresolution schemes. We show that this prediction is well-defined, construct a Harten multiresolution using this prediction, and show that a modified encoding strategy is possible for approximation using the scheme. We also investigate the efficient numerical solution of the prediction and compare several different algorithms. Examples show that image approximation with this scheme is competitive with the CDF 9/7 wavelet. Next, we investigate nonconvex potentials in variational image problems. For the approximate solution of these nonconvex problems, we develop a particle swarm optimization like algorithm that avoids becoming

  10. Geographical variation and the determinants of domestic endotoxin levels in mattress dust in Europe

    NARCIS (Netherlands)

    Chen, C.M.; Thiering, E.; Doekes, G.|info:eu-repo/dai/nl/070079803; Zock, J.P.|info:eu-repo/dai/nl/095184309; Bakolis, I.; Norbäck, D.; Sunyer, J.; Villani, S.; Verlato, G.; Täubel, M.; Jarvis, D.

    2012-01-01

    Endotoxin exposures have manifold effects on human health. The geographical variation and determinants of domestic endotoxin levels in Europe have not yet been extensively described. To investigate the geographical variation and determinants of domestic endotoxin concentrations in mattress dust in

  11. Seasonal genetic variation associated with population dynamics of a poecilogonous polychaete worm

    DEFF Research Database (Denmark)

    Thonig, Anne; Banta, Gary Thomas; Hansen, Benni Winding

    2017-01-01

    Poecilogonous species show variation in developmental mode, with larvae that differ both morphologically and ecologically. The spionid polychaete Pygospio elegans shows variation in developmental mode not only between populations, but also seasonally within populations. We investigated the conseq...

  12. Stored ions in the Paul trap. Preliminary investigations on life-time measurement of the metastable 6D3/2 state of 226Ra+, storage properties of 138Ba+ and 28N2+ at variation of the buffer-gas pressure

    International Nuclear Information System (INIS)

    Leuthner, Heiko

    2011-01-01

    Paul-traps are a widely used tool in scientific research and play an important role in atomic physics and mass spectrometry. (1) From the earth-alkaline ions only spectroscopic data of Ra + are lacking. Those are important for the test of theoretical models and for a future atomic parity violation experiment. The first part of this work describes the setting up of a Paul-trap based Laser-experiment for measuring the lifetime of the 6D 3/2 state of 226 Ra + . Basic tests with 138 Ba + ions are presented. (2) Damping and space charge effects on resonances in the stability region strongly affect the use of Paul-traps in mass spectrometry and analysis of reaction products. The second part of this work presents detailed investigations on the storage of big, buffer-gas-cooled ion clouds in two different Paul-trap experiments; the first of them uses 138 Ba + ions detected continuously by electronic and optical detection systems, the second one uses N 2 + molecular ions and an automated destructive time-of-flight-detection method. A high precision measurement with N 2 + of the first stability region of the trap not only gives the possibility of direct comparison of experimental and theoretical resonances but also provides absolute ion numbers over the whole region for the first time. Unlike previous measurements, the investigations on nonlinear resonances where done on the superimposed stability regions of 4 simultaneously stored ion species. The nonlinear resonances were studied by varying buffer gas pressure and ion number and showed collective resonances without external excitation. By varying the buffer gas pressure the spatial distribution of a Ba + -ion cloud was investigated as well as the change of the optimal storing parameters using N 2 + -ions. Optimum Pressures for catching and trapping of ions turned out to be unequal. Shape and position of externally excited collective and individual resonances were studied under variation of ion number, buffer-gas pressure

  13. A variational approach to closed bosonic strings on bordered Riemann surfaces

    International Nuclear Information System (INIS)

    Ohrndorf, T.

    1987-01-01

    Polyakov's path integral for bosonic closed strings defined on a bordered Riemann surface is investigated by variational methods. It is demonstrated that boundary variations are generated by the Virasoro operators. The investigation is performed for both, simply connected Riemann surfaces as well as ringlike domains. It is shown that the form of the variational operator is the same on both kinds of surfaces. The Virasoro algebra arises as a consistency condition for the variation. (orig.)

  14. A survey of variational principles

    International Nuclear Information System (INIS)

    Lewins, J.D.

    1993-01-01

    In this article survey of variational principles has been given. Variational principles play a significant role in mathematical theory with emphasis on the physical aspects. There are two principals used i.e. to represent the equation of the system in a succinct way and to enable a particular computation in the system to be carried out with greater accuracy. The survey of variational principles has ranged widely from its starting point in the Lagrange multiplier to optimisation principles. In an age of digital computation, these classic methods can be adapted to improve such calculations. We emphasize particularly the advantage of basic finite element methods on variational principles. (A.B.)

  15. Severity investigation

    NARCIS (Netherlands)

    Rooij, M.R. de; Godart, B.

    2013-01-01

    From the confirmation inspection and its subsequent test results the presence of AAR has either been confirmed or eliminated. Assuming the first outcome, the next step is to investigate the severity of the situation, see Figure 23. One should keep in mind that it is possible that some evidence of

  16. Investigating Corruption

    OpenAIRE

    Prendergast, Canice

    2000-01-01

    Agency theory has had little to say about the control of bureaucratic corruption, perhaps the greatest agency problem that exists. The author considers the role of incentive contracting in reducing corruption through the use of independent investigations-a common way to monitor corruption. In simple settings, bureaucratic corruption can be suppressed by rewarding and penalizing bureaucrats...

  17. Seasonal variation in food allergy to apple

    DEFF Research Database (Denmark)

    Skamstrup Hansen, K; Vieths, S; Vestergaard, H

    2001-01-01

    The aim of the study was to investigate the possibility of a seasonal variation in reactivity to apples in 27 birch pollen allergic patients. Before and during the birch pollen season 1998, the patients were subjected to double-blind, placebo-controlled food challenges (DBPCFCs) with grated fresh...... Golden Delicious apple followed by an open food challenge with whole fresh apple. The clinical reactions elicited during the challenges were evaluated both by the patients and the investigators. Moreover, the skin reactivity and the in vitro reactivity to apple were evaluated by skin prick test (SPT...

  18. Seasonal variations of haematological parameters in athletes.

    Science.gov (United States)

    Banfi, Giuseppe; Lundby, Carsten; Robach, Paul; Lippi, Giuseppe

    2011-01-01

    The influence of training and competition workloads is crucial for evaluation of longitudinal haematological data in athletes. There are only a few papers on the variation of haematological parameters during long-lasting periods and, especially, during an entire competitive season. We summarized that some haematological parameters can be influenced by long-term training and competition periods. Haemoglobin (Hb) and haematocrit (Ht) are decreased during the more intense periods of training, throughout the season. In different sport disciplines, the decline of Hb ranges from 3 to 8% during the competition season, while the range of reticulocytes (Ret%) varies from 5 to 21%. Reticulocytes are also decreased after long periods of training and competitions, but their variation is not necessarily associated with that of Hb. The qualitative variations (trend of modifications) of haematological parameters are roughly independent of the sport discipline, but quantitatively (amount of modifications) dependent on sport discipline. The modifications are more evident in cycling, running, swimming than they are in football and rugby. The variations of haematological parameters within the same sport discipline are qualitatively concordant and quantitatively different among separate but consecutive competitive seasons. These findings are described in aerobic and team sports sportsmen. The definition of reliable reference ranges in sportsmen would only be possible by following the best laboratory practices. For antidoping purposes more studies investigating haematological modifications during the season are advisable.

  19. General strongly nonlinear variational inequalities

    International Nuclear Information System (INIS)

    Siddiqi, A.H.; Ansari, Q.H.

    1990-07-01

    In this paper we develop iterative algorithms for finding approximate solutions for new classes of variational and quasi-variational inequalities which include, as special case, some known results in this field. It is shown that the solutions of the iterative schemes converge to the exact solutions. (author). 15 refs

  20. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.; Sanchez-Serrano, J.J.; Salinas, J.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  1. Variations of interferometer types

    International Nuclear Information System (INIS)

    Graeff, W.

    1978-01-01

    The search for other interferometer configurations than the LLL interferometer that has been proved to work satisfactorily, has two reasons: first some disadvantages of the LLL interferometer like the smearins of the beams over the Borrmann fan or the loss of half of the intensity in the Laue case mirror may be overcome by changing the geometry. Secondly, problems of neutron optics like details of wave propagation in perfect and nearly perfect crystals coherence etc. can be investigated by varying the properties of the interferometer components. The discussion is restricted to those inteferometer types where Bragg diffracting single crystals are used for beam handling

  2. Geotechnical Investigations

    Science.gov (United States)

    2001-01-01

    assessment are discussed in Construction Site Environmental Survey and Clearance Procedures Manual (Draft), EM 1110-1-4000, Walker (1988), and Borrelli ...EM 1110-1-1804 1 January 2001 US Army Corps of Engineers ENGINEER MANUAL Geotechnical Investigations ENGINEERING AND DESIGN Report Documentation Page...for all official USACE engineer regulations, circulars, manuals , and other documents originating from HQUSACE. Publications are provided in portable

  3. Investigations of SPS orbit drifts

    CERN Document Server

    Drøsdal, L; Cornelis, K; Goddard, B; Kain, V; Meddahi, M; Wenninger, J; Gianfelice-Wendt, E

    2014-01-01

    The LHC is filled from the last pre-injector, the Super Proton Synchrotron (SPS), via two 3 km long transfer lines, TI 2 and TI 8. Over the LHC injection processes, a drift of the beam trajectories has been observed in TI 2 and TI 8, requiring regular correction of the trajectories, in order to ensure clean injection into the LHC. Investigations of the trajectory variations in the transfer lines showed that the main source of short term trajectory drifts are current variations of the SPS extraction septa (MSE). The stability of the power converters has been improved, but the variations are still present and further improvements are being investigated. The stability over a longer period of time cannot be explained by this source alone. The analysis of trajectory variations shows that there are also slow variations in the SPS closed orbit at extraction. A set of SPS orbit measurements has been saved and analysed. These observations will be used together with simulations and observed field errors to locate the s...

  4. Biological variation of thyroid autoantibodies and thyroglobulin

    DEFF Research Database (Denmark)

    Jensen, Esther; Petersen, Per Hyltoft; Blaabjerg, Ole

    2007-01-01

    is unknown, we investigated this in fertile women during one complete regular menstrual cycle. METHODS: A total of 24 healthy women (23-46 years) were investigated twice a week between 07:30 and 11:00 h. Antibodies against thyroid peroxidase (TPOAb), thyroglobulin (TgAb), and thyrotropin receptor (TRAb) were...... the upper reference limit of the laboratory (6 had TPOAb >10 kIU/L, 6 had TgAb >20 kIU/L and 1 had TRAb >0.75 IU/L). Eight women had Tg below the lower reference limit, five of whom had elevated TgAb. Variations in the thyroid antibodies were random and not related to the menstrual cycle. For TPOAb (2......: It is possible to measure TPOAb and TgAb in all samples with the AutoDELFIA. There is no systematic variation in autoantibodies during the menstrual cycle. The biological coefficient of variation for TPOAb and TgAb was 11.3% and 8.5%, respectively...

  5. Case variation in coordination: Danish vs. Faroese

    Directory of Open Access Journals (Sweden)

    Jeffrey K. Parrott

    2009-01-01

    Full Text Available This paper is primarily concerned with inter- and intra-individually variable case-form mismatches inside coordinate determiner phrases (CoDPs. For English, the phenomenon is both socially salient (e.g., O'Conner & Kellerman 2009, among many others and well studied (Angermeyer & Singler 2003, Quinn 2005, Grano 2006, Parrott 2007: Ch. 6. The most prominent theory of (default case (Schütze 2001, incorporating Johannessen 1998 explains English variation in CoDPs mostly with parameterized syntactic mechanisms. The parametric theory does not make clear cross-linguistic predictions, and accordingly there has been little cross-linguistic investigation of case variation in CoDPs. This paper therefore has two main purposes. The first is to argue for a theory of (default case (Parrott 2007, 2009a, following Emonds 1986, and incorporating McFadden 2004, 2007 within the Distributed Morphology (DM framework (Halle & Marantz 1993, Embick & Noyer 2007. In contrast with the parametric theory, the DM theory makes testable cross-linguistic predictions that, inter alia, connect the (non attestation of case mismatches in CoDPs with Germanic case typology. Thus, the paper’s second purpose is to present some results from investigations, utilizing diverse empirical methods, into case variation in CoDPs for Danish and Faroese. These results are consistent with predictions made by the DM theory.

  6. Modeling the climatic response to orbital variations.

    Science.gov (United States)

    Imbrie, J; Imbrie, J Z

    1980-02-29

    According to the astronomical theory of climate, variations in the earth's orbit are the fundamental cause of the succession of Pleistocene ice ages. This article summarizes how the theory has evolved since the pioneer studies of James Croll and Milutin Milankovitch, reviews recent evidence that supports the theory, and argues that a major opportunity is at hand to investigate the physical mechanisms by which the climate system responds to orbital forcing. After a survey of the kinds of models that have been applied to this problem, a strategy is suggested for building simple, physically motivated models, and a time-dependent model is developed that simulates the history of planetary glaciation for the past 500,000 years. Ignoring anthropogenic and other possible sources of variation acting at frequencies higher than one cycle per 19,000 years, this model predicts that the long-term cooling trend which began some 6000 years ago will continue for the next 23,000 years.

  7. Urban building recognition during significant temporal variations

    DEFF Research Database (Denmark)

    Nguyen, Phuong Giang; Andersen, Hans Jørgen

    2008-01-01

    In literature, existing researches on building recognition mainly concentrate on scales, rotations, and viewpoints variance. In urban environment, large temporal variations of weather and lighting conditions should also be considered as major challenges for robust recognition. For instances......, there are differences between images captured during daytime and nighttime, especially significant changes in building appearances between seasons because of the differences in light setting. To date, these large temporal variation issues have not been fully investigated. In this paper, we therefore focus...... on constructing a system that deals with the temporal difference factors in recognizing urban buildings. In order to build such a system, two main criteria are raised, namely the efficiency of the recognition algorithm and the speed for interactive search purpose. For recognition purpose, we exploit the MOPS...

  8. Seasonal variations of equatorial spread-F

    Directory of Open Access Journals (Sweden)

    K. S. V. Subbarao

    1994-01-01

    Full Text Available The occurrence of spread-F at Trivandrum (8.5°N, 77°E, dip 0.5°N has been investigated on a seasonal basis in sunspot maximum and minimum years in terms of the growth rate of irregularities by the generalized collisional Rayleigh-Taylor (GRT instability mechanism which includes the gravitational and cross-field instability terms. The occurrence statistics of spread-F at Trivandrum have been obtained using quarter hourly ionograms. The nocturnal variations of the growth rate of irregularities by the GRT mechanism have been estimated for different seasons in sunspot maximum and minimum years at Trivandrum using h'F values and vertical drift velocities obtained from ionograms. It is found that the seasonal variation of spread-F occurrence at Trivandrum can, in general, be accounted for on the basis of the GRT mechanism.

  9. Variational approach to 68 Se

    International Nuclear Information System (INIS)

    Petrovici, A.; Schmid, K.W.; Faessler, A.; Baktash, C.; Shashi, P.

    1999-01-01

    For a unified description of the structure of medium mass proton-rich nuclei at low as well as high angular momenta we used the complex version of the Excited Vampir approach. We employed chains of variational calculations based on symmetry-projected essentially complex Hartree-Fock-Bogoliubov (HFB) vacua which include neutron-proton pairing and unnatural-parity correlations. Since the Vampir approaches allow the use of rather large model spaces and of general two-body interactions, large-scale nuclear structure studies going far beyond the abilities of the conventional shell-model configuration-mixing approach are possible. Furthermore, since these approaches provide detailed spectroscopic information for the lowest few states for each spin and parity, they also have considerable advantages with respect to the shell-model Monte Carlo method in which only expectation values of operators in the thermodynamic ensembles or the ground state can be calculated. Our previous investigations on microscopic aspects of shape coexistence in N∼Z nuclei in the A∼70 mass region indicated the presence of a strong competition between particular configurations based on large and small oblate and prolate quadrupole deformations. Furthermore, since in N = Z nuclei neutrons and protons fill the same single particle orbits, the isovector neutron-proton and the like-nucleon pairing correlations were found to be strongly competitive in even-even systems. In addition, the neutron and proton alignments with increasing angular momentum occur simultaneously in these nuclei. On the other hand the theoretical results suggest that certain properties of these nuclei are extremely sensitive to small variations of particular parts of the effective Hamiltonian. Thus, our results indicate that the oblate-prolate coexistence and mixing at low spins depend on the strengths of the neutron-proton T = 0 matrix elements involving nucleons occupying f 5/2 (f 7/2 ) and g 9/2 single particle orbits

  10. Observer variation in skeletal radiology

    Energy Technology Data Exchange (ETDEWEB)

    Cockshott, W.P.; Park, W.M.

    1983-08-01

    The factors that affect observer variation in bone radiology are analysed from data in the literature and on the basis of studies carried out at McMaster University on the hands and sacroiliac joints. A plea is made for presenting results in terms of Kappa statistics so that agreement due purely to chance is eliminated. In the conclusions the main variables that affect concordance are listed so that strategies can be developed to reduce observer variation. This is important in serial studies to ensure that the observer variations are smaller than the effect one wishes to measure.

  11. Statistics, Uncertainty, and Transmitted Variation

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, Joanne Roth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-05

    The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.

  12. Crosshole investigations

    International Nuclear Information System (INIS)

    Olsson, O.; Pihl, J.

    1987-09-01

    The analysis of the radar and seismic data has given a consistent description of the fracture zones at the Crosshole site in agreement with geological and other geophysical observations made in the boreholes. The hydraulic investigations within the Crosshole project have yielded substantial progress in assessing the hydrogeology of fractured granitic rocks. The crosshole hydraulic testing concentrated on measuring the distribution of hydraulic properties within the extensive fractured zones identified by geophysics. A new analysis involving the 'dimension' of the flow test has been developed to analyse the results of the crosshole sinusoidal testing. The combined analysis of the geophysical and the hydraulic data set has shown that groundwater flow is concentrated within a few major features which have been identified by the geophysical methods. (orig./DG)

  13. Laboratory investigations

    International Nuclear Information System (INIS)

    Handin, J.

    1980-01-01

    Our task is to design mined-repository systems that will adequately secure high-level nuclear waste for at least 10,000 yr and that will be mechanically stable for 50 to 100-yr periods of retrievability during which mistakes could be corrected and a valuable source of energy could be reclaimed, should national policy on the reprocessing of spent fuel ever change. The only credible path for the escape of radionuclides from the repository to the biosphere is through ground-water, and in hard rock, bulk permeability is largely governed by natural and artificial fracture systems. Catastrophic failure of an excavation in hard rock is likely to occur at the weakest links - the discontinuities in the rock mass that is perturbed first by mining and then by radiogenic heating. The laboratory can contribute precise measurements of the pertinent thermomechanical, hydrological and chemical properties and improve our understanding of the fundamental processes through careful experiments under well controlled conditions that simulate the prototype environment. Thus laboratory investigations are necessary, but they are not sufficient, for conventional sample sizes are small relative to natural defects like joints - i.e., the rock mass is not a continuum - and test durations are short compared to those that predictive modeling must take into account. Laboratory investigators can contribute substantially more useful data if they are provided facilities for testing large specimens(say one cubic meter) and for creep testing of all candidate host rocks. Even so, extrapolations of laboratory data to the field in neither space nor time are valid without the firm theoretical foundations yet to be built. Meanwhile in-situ measurements of structure-sensitive physical properties and access to direct observations of rock-mass character will be absolutely necessary

  14. Diurnal variation of radon progeny

    International Nuclear Information System (INIS)

    Seftelis, I.; Nicolaou, G.; Trassanidis, S.; Tsagas, F.N.

    2007-01-01

    The diurnal variation of the gross alpha (α) radioactivity in the air near the ground and the gamma (γ) radioactivity emitted from the ground have been monitored in North-eastern Greece. Meteorological information comprising air temperature and humidity has been simultaneously recorded. Over a period of the 24 h of a typical day, the variation of α-radioactivity reaches a peak in the morning followed by a remarkable decrease, rising to a second peak in the afternoon. Furthermore, its significant dependence on the air temperature and humidity is confirmed, rising with an increase in humidity and decrease in temperature. The variation of the ground γ-radioactivity follows that of the air α-radioactivity. A mathematical model has been developed to describe the diurnal variation of the α-radioactivity in the air near the ground in terms of the above meteorological variables and ground level γ-radioactivity

  15. Fractional variational principles with delay

    International Nuclear Information System (INIS)

    Baleanu, Dumitru; Abdeljawad, Thabet Maaraba; Jarad, Fahd

    2008-01-01

    The fractional variational principles within Riemann-Liouville fractional derivatives in the presence of delay are analyzed. The corresponding Euler-Lagrange equations are obtained and one example is analyzed in detail

  16. Explaining variation in nascent entrepreneurship

    NARCIS (Netherlands)

    A.J. van Stel (André); A.R.M. Wennekers (Sander); P. Reynolds (Paul); A.R. Thurik (Roy)

    2004-01-01

    textabstractThis paper aims at explaining cross-country variation in nascent entrepreneurship. Regression analysis is applied using various explanatory variables derived from three different approaches. We make use of the Global Entrepreneurship Monitor database, including nascent entrepreneurship

  17. Variational aspects of Faddeev calculations

    International Nuclear Information System (INIS)

    Payne, G.L.; Gibson, B.F.

    1993-01-01

    Variational bounds generated from Faddeev solutions for various realistic potential models are presented as a function of the number of partial waves retained in the potential expansion. The authors demonstrate that the Faddeev wave function yields an optimal variational bound for the partial-wave truncated potential from which it was generated, but it does not yield an optimal bound for the full Hamiltonian or when the potential is partial-wave truncated at a different level

  18. Variational calculus on Banach spaces

    International Nuclear Information System (INIS)

    Uglanov, A V

    2000-01-01

    The problem of variational calculus is considered in a (variable) subdomain of a Banach space. Analogues of the basic principles of the finite-dimensional theory are derived: the main formula for variations of a functional, necessary conditions of an extremum, Noether's theorem. All the results obtained are dimension-invariant and become the classical ones in the finite-dimensional setting. The main tool of the analysis is the theory of surface integration in Banach spaces

  19. Nonlinear Analysis and Variational Problems

    CERN Document Server

    Pardalos, Panos M

    2010-01-01

    The chapters in this volume, written by international experts from different fields of mathematics, are devoted to honoring George Isac, a renowned mathematician. These contributions focus on recent developments in complementarity theory, variational principles, stability theory of functional equations, nonsmooth optimization, and several other important topics at the forefront of nonlinear analysis and optimization. "Nonlinear Analysis and Variational Problems" is organized into two parts. Part I, Nonlinear Analysis, centers on stability issues for functional equations, fixed point

  20. Variational model for one-dimensional quantum magnets

    Science.gov (United States)

    Kudasov, Yu. B.; Kozabaranov, R. V.

    2018-04-01

    A new variational technique for investigation of the ground state and correlation functions in 1D quantum magnets is proposed. A spin Hamiltonian is reduced to a fermionic representation by the Jordan-Wigner transformation. The ground state is described by a new non-local trial wave function, and the total energy is calculated in an analytic form as a function of two variational parameters. This approach is demonstrated with an example of the XXZ-chain of spin-1/2 under a staggered magnetic field. Generalizations and applications of the variational technique for low-dimensional magnetic systems are discussed.

  1. Secular trends in seasonal variation in birth weight

    DEFF Research Database (Denmark)

    B. Jensen, Camilla; Gamborg, Michael; Raymond, Kyle

    2015-01-01

    BACKGROUND: Many environmental factors have been shown to influence birth weight (BW) and one of these are season of birth. AIM: The aim of the present study was to investigate the seasonal variation in BW in Denmark during 1936-1989, and to see if the variation could be explained by sunshine...... exposure during pregnancy. METHODS: The study population was selected from the Copenhagen School Health Records Register and included 276 339 children born between 1936 and 1989. Seasonal variation was modeled using a non-stationary sinusoidal model that allowed the underlying trend in BW and the amplitude...

  2. Genomic variation in Salmonella enterica core genes for epidemiological typing

    DEFF Research Database (Denmark)

    Leekitcharoenphon, Pimlapas; Lukjancenko, Oksana; Rundsten, Carsten Friis

    2012-01-01

    genomes and evaluate their value as typing targets, comparing whole genome typing and traditional methods such as 16S and MLST. A consensus tree based on variation of core genes gives much better resolution than 16S and MLST; the pan-genome family tree is similar to the consensus tree, but with higher...... that there is a positive selection towards mutations leading to amino acid changes. Conclusions: Genomic variation within the core genome is useful for investigating molecular evolution and providing candidate genes for bacterial genome typing. Identification of genes with different degrees of variation is important...

  3. Planck intermediate results XXIV. Constraints on variations in fundamental constants

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Arnaud, M.

    2015-01-01

    cosmological probes. We conclude that independent time variations of the fine structure constant and of the mass of the electron are constrained by Planck to Δ Α/Α = (3.6±3.7) x 10-3 and Δ me/me = (4 ±11) x 10-3 at the 68% confidence level. We also investigate the possibility of a spatial variation of the fine...

  4. Continuous radon measurements in schools: time variations and related parameters

    International Nuclear Information System (INIS)

    Giovani, C.; Cappelletto, C.; Garavaglia, M.; Pividore, S.; Villalta, R.

    2004-01-01

    Some results are reported of observations made within a four-year survey, during different seasons and in different conditions of school building use. Natural radon variations (day-night cycles, seasonal and temperature dependent variations etc..) and artificial ones (opening of windows, weekends and vacations, deployment of air conditioning or heating systems. etc.) were investigated as parameters affecting time dependent radon concentrations. (P.A.)

  5. Genetic variation in genes affecting milk composition and quality

    DEFF Research Database (Denmark)

    Bertelsen, Henriette Pasgaard

    associated with complex traits. In the present PDH projekt the main emphasis has been on investigating the complex trait of milk coagulation. Utilising a next generation wequencing approach on polled samples resulted in the detection of novel SNPs and possible condidate genes affection milk coagulation....... In addition, exploring genetic variation related to the major milk proteins of bovine milk indntified genetic variations with possitive effects on milk coagulation...

  6. Is there much variation in variation? Revisiting statistics of small area variation in health services research

    Directory of Open Access Journals (Sweden)

    Ibáñez Berta

    2009-04-01

    Full Text Available Abstract Background The importance of Small Area Variation Analysis for policy-making contrasts with the scarcity of work on the validity of the statistics used in these studies. Our study aims at 1 determining whether variation in utilization rates between health areas is higher than would be expected by chance, 2 estimating the statistical power of the variation statistics; and 3 evaluating the ability of different statistics to compare the variability among different procedures regardless of their rates. Methods Parametric bootstrap techniques were used to derive the empirical distribution for each statistic under the hypothesis of homogeneity across areas. Non-parametric procedures were used to analyze the empirical distribution for the observed statistics and compare the results in six situations (low/medium/high utilization rates and low/high variability. A small scale simulation study was conducted to assess the capacity of each statistic to discriminate between different scenarios with different degrees of variation. Results Bootstrap techniques proved to be good at quantifying the difference between the null hypothesis and the variation observed in each situation, and to construct reliable tests and confidence intervals for each of the variation statistics analyzed. Although the good performance of Systematic Component of Variation (SCV, Empirical Bayes (EB statistic shows better behaviour under the null hypothesis, it is able to detect variability if present, it is not influenced by the procedure rate and it is best able to discriminate between different degrees of heterogeneity. Conclusion The EB statistics seems to be a good alternative to more conventional statistics used in small-area variation analysis in health service research because of its robustness.

  7. [Geographic variations in freshwater molluscs].

    Science.gov (United States)

    Vinarskiĭ, M V

    2012-01-01

    The phenomenon of geographic variation is known in practically all taxa of living beings. However, the reality of this phenomenon in freshwater molluscs (snails and bivalves) has many times been questioned in the past. It was accepted that these animals do not demonstrate spatially-oriented variation, where specific "local race" is arisen in each specific habitat. Till the beginning of 1970s, there was no statistical evidence that geographic clines in freshwater molluscs really exist. However, a few species of freshwater molluscs has been studied in this respect so far, therefore it is almost impossible to draw any general patterns of geographical variation in this group of animals. Most species of freshwater molluscs studied to the date exhibit statistically significant decrease of their body size in the south-north direction. Perhaps, it may be explained by decrease of the duration of the growth season in high latitudes. Some species of freshwater snails demonstrate clinal changes in shell proportions. This allows to reject subspecies separation within these species since diagnostic characters of such "subspecies" may blur when geographic variation is taken into consideration. The data on geographic variation in anatomical traits in freshwater molluscs is much more scarce. At least one species of pond snails (Lymnaea terebra) demonstrates clinal variation in proportions of the copulative apparatus in the south-north direction. Further studies of geographic variation in freshwater molluscs should reveal whether it is truly adaptive, i.e. whether geographical clines have underlying genetic basis. Otherwise, the clines may arise as a result of direct modifying effect of a habitat.

  8. Variation of Natural Gamma Radiation in Isparta

    International Nuclear Information System (INIS)

    Akkurt, I.

    2004-01-01

    There is always a radiation in the earth, and its level is generated primarily by galactic cosmic rays (GCR), consisting of energetic nuclei of all naturally occurring elements, interacting with atmospheric constituents, through atomic and nuclear collisions. The other sources of natural radiations are global average background radiation from terrestrial sources such as soils, rocks ete. Background radiation levels in the atmosphere vary in intensity with latitude, altitude and phase of the solar cycle. Variation of natural radiation as a function of altitude, geological structure etc has been investigated. The measurements were performed using portable radiation counter which connected to NaI(Tl) probe

  9. Short period tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.; Dickey, J. O.

    1981-01-01

    It is explained that the tidal deformation of the earth's polar moment of inertia by the moon and sun cause periodic variations in rotation. The short period oscillations give rise to a meter-sized, diurnal signature in the lunar laser ranging data obtained at McDonald Observatory. A solution is given for the scale parameter k/C at fortnightly and monthly tidal frequencies. The results are compared with those obtained by other investigators and with a theoretical estimate which includes the effect of oceans and a decoupled fluid core.

  10. Epigenetic variation during the adult lifespan

    DEFF Research Database (Denmark)

    Talens, Rudolf P; Christensen, Kaare; Putter, Hein

    2012-01-01

    The accumulation of epigenetic changes was proposed to contribute to the age-related increase in the risk of most common diseases. In this study on 230 monozygotic twin pairs (MZ pairs), aged 18-89 years, we investigated the occurrence of epigenetic changes over the adult lifespan. Using mass......-related increase in methylation variation was generally attributable to unique environmental factors, except for CRH, for which familial factors may play a more important role. In conclusion, sustained epigenetic differences arise from early adulthood to old age and contribute to an increasing discordance of MZ...

  11. Variation of surface dose in CT

    International Nuclear Information System (INIS)

    Aviles Lucas, P.; Castellano, I. A.; Dance, D. R.; Vano Carruana, E.; Prieto Martin, C.

    2003-01-01

    An experimental study has been made of the variations of the air kerma-length product at the surface of a phantom exposed in a CT scanner using clinical parameters. the effect of patient size, position within the gantry plane and beam-shaping filter type was studied using three different elliptical phantoms. A dose reduction technique based on a sinusoidal tube current modulation system was also investigated. the result of the variation of the surface dose was analysed for the case of CT fluoroscopy procedures. The surface air kerma-length product was shown to be independent of phantom size (within experimental error) but decreases as the surface moves vertically away from the iso centre. The major contributor to this variation the beam-shaping filter. The possibility of underestimating the surface dose if an AAPM body phantom is used (a 36% increase for the head phantom) is an indirect result of the previous conclusion when applied to CT fluoroscopy. This highlights the importance of considering the size and position of the patient when measuring the does. Finally, when the tube current modulation system was used, the maximum surface dose reduction was 18%. (Author) 23 refs

  12. Total Variation Depth for Functional Data

    KAUST Repository

    Huang, Huang

    2016-11-15

    There has been extensive work on data depth-based methods for robust multivariate data analysis. Recent developments have moved to infinite-dimensional objects such as functional data. In this work, we propose a new notion of depth, the total variation depth, for functional data. As a measure of depth, its properties are studied theoretically, and the associated outlier detection performance is investigated through simulations. Compared to magnitude outliers, shape outliers are often masked among the rest of samples and harder to identify. We show that the proposed total variation depth has many desirable features and is well suited for outlier detection. In particular, we propose to decompose the total variation depth into two components that are associated with shape and magnitude outlyingness, respectively. This decomposition allows us to develop an effective procedure for outlier detection and useful visualization tools, while naturally accounting for the correlation in functional data. Finally, the proposed methodology is demonstrated using real datasets of curves, images, and video frames.

  13. Influence of design variations on controlled thermonuclear reactor blanket neutronic performance using variational techniques

    International Nuclear Information System (INIS)

    Cheng, E.T.; Conn, R.W.

    1977-01-01

    The influence of design variations, such as the percentage of structural material in a tritium breeding zone or the enrichment of lithium in 6 Li, on such important controlled thermonuclear reactor parameters as the tritium breeding ratio and the total nuclear energy produced has been studied using variational techniques for two different but general blanket designs. The first design uses liquid lithium as both coolant and breeding material, while the second uses a helium coolant and a solid-lithium-bearing compound as the tritium breeder. A variational technique based on variational interpolation is the primary computational tool, and it is shown that for linear perturbations in the transport operator and for a fixed source, only forward flux calculations are required to implement the variational interpolation approach. No adjoint functions are required to implement the variational interpolation approach. No adjoint functions are required, while any number of response functionals can be investigated. For both blanket designs, the influence of the choice of structural material, such as stainless-steel, molybdenum, niobium, vanadium, and aluminum structures, has been studied. The role of beryllium as a neutron multiplier with a solid breeder blanket is studied, and an optimum beryllium thickness is found that maximizes the breeding ratio. The influence of using graphite or the structural material as a neutron reflector and the effect of lithium burnup are also studied. It is found that for a given percentage of structural material in the tritium breeding zones, vanadium-structured systems achieve the highest breeding ratios, while molybdenum-structured systems produce the highest value of total nuclear heating. The effects of lithium burnup are small

  14. Stochastic macromodel of magnetic tunnel junction resistance variation and critical current dependence on resistance variation for SPICE simulation

    Science.gov (United States)

    Choi, Juntae; Song, Yunheub

    2017-04-01

    The resistance distribution of a magnetic tunnel junction (MTJ) shows nonuniformity according to various MTJ parameters. Moreover, this resistance variation leads to write-current density variation, which can cause serious problems when designing peripheral circuits for spin transfer torque magnetoresistance random access memory (STT-MRAM) and commercializing gigabit STT-MRAM. Therefore, a macromodel of MTJ including resistance, tunneling magnetoresistance ratio (TMR), and critical current variations is required for circuit designers to design MRAM peripheral circuits, that can overcome the various effects of the variations, such as write failure and read failure, and realize STT-MRAM. In this study, we investigated a stochastic behavior macromodel of the write current dependence on the MTJ resistance variation. The proposed model can possibly be used to analyze the write current density in relation to the resistance and TMR variations of MTJ with various parameter variations. It can be very helpful for designing STT-MRAM circuits and simulating the operation of STT-MRAM devices considering MTJ variations.

  15. Seasonal variation in sports participation.

    Science.gov (United States)

    Schüttoff, Ute; Pawlowski, Tim

    2018-02-01

    This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

  16. Geographic variation in gorilla limb bones.

    Science.gov (United States)

    Jabbour, Rebecca S; Pearman, Tessa L

    2016-06-01

    Gorilla systematics has received increased attention over recent decades from primatologists, conservationists, and paleontologists. Studies of geographic variation in DNA, skulls, and teeth have led to new taxonomic proposals, such as recognition of two gorilla species, Gorilla gorilla (western gorilla) and Gorilla beringei (eastern gorilla). Postcranial differences between mountain gorillas (G. beringei beringei) and western lowland gorillas (G. g. gorilla) have a long history of study, but differences between the limb bones of the eastern and western species have not yet been examined with an emphasis on geographic variation within each species. In addition, proposals for recognition of the Cross River gorilla as Gorilla gorilla diehli and gorillas from Tshiaberimu and Kahuzi as G. b. rex-pymaeorum have not been evaluated in the context of geographic variation in the forelimb and hindlimb skeletons. Forty-three linear measurements were collected from limb bones of 266 adult gorillas representing populations of G. b. beringei, Gorilla beringei graueri, G. g. gorilla, and G. g. diehli in order to investigate geographic diversity. Skeletal elements included the humerus, radius, third metacarpal, third proximal hand phalanx, femur, tibia, calcaneus, first metatarsal, third metatarsal, and third proximal foot phalanx. Comparisons of means and principal components analyses clearly differentiate eastern and western gorillas, indicating that eastern gorillas have absolutely and relatively smaller hands and feet, among other differences. Gorilla subspecies and populations cluster consistently by species, although G. g. diehli may be similar to the eastern gorillas in having small hands and feet. The subspecies of G. beringei are distinguished less strongly and by different variables than the two gorilla species. Populations of G. b. graueri are variable, and Kahuzi and Tshiaberimu specimens do not cluster together. Results support the possible influence of

  17. Lexical Variation and Change in British Sign Language

    Science.gov (United States)

    Stamp, Rose; Schembri, Adam; Fenlon, Jordan; Rentelis, Ramas; Woll, Bencie; Cormier, Kearsy

    2014-01-01

    This paper presents results from a corpus-based study investigating lexical variation in BSL. An earlier study investigating variation in BSL numeral signs found that younger signers were using a decreasing variety of regionally distinct variants, suggesting that levelling may be taking place. Here, we report findings from a larger investigation looking at regional lexical variants for colours, countries, numbers and UK placenames elicited as part of the BSL Corpus Project. Age, school location and language background were significant predictors of lexical variation, with younger signers using a more levelled variety. This change appears to be happening faster in particular sub-groups of the deaf community (e.g., signers from hearing families). Also, we find that for the names of some UK cities, signers from outside the region use a different sign than those who live in the region. PMID:24759673

  18. Variational methods in molecular modeling

    CERN Document Server

    2017-01-01

    This book presents tutorial overviews for many applications of variational methods to molecular modeling. Topics discussed include the Gibbs-Bogoliubov-Feynman variational principle, square-gradient models, classical density functional theories, self-consistent-field theories, phase-field methods, Ginzburg-Landau and Helfrich-type phenomenological models, dynamical density functional theory, and variational Monte Carlo methods. Illustrative examples are given to facilitate understanding of the basic concepts and quantitative prediction of the properties and rich behavior of diverse many-body systems ranging from inhomogeneous fluids, electrolytes and ionic liquids in micropores, colloidal dispersions, liquid crystals, polymer blends, lipid membranes, microemulsions, magnetic materials and high-temperature superconductors. All chapters are written by leading experts in the field and illustrated with tutorial examples for their practical applications to specific subjects. With emphasis placed on physical unders...

  19. Solid mechanics a variational approach

    CERN Document Server

    Dym, Clive L

    2013-01-01

    Solid Mechanics: A Variational Approach, Augmented Edition presents a lucid and thoroughly developed approach to solid mechanics for students engaged in the study of elastic structures not seen in other texts currently on the market. This work offers a clear and carefully prepared exposition of variational techniques as they are applied to solid mechanics. Unlike other books in this field, Dym and Shames treat all the necessary theory needed for the study of solid mechanics and include extensive applications. Of particular note is the variational approach used in developing consistent structural theories and in obtaining exact and approximate solutions for many problems.  Based on both semester and year-long courses taught to undergraduate seniors and graduate students, this text is geared for programs in aeronautical, civil, and mechanical engineering, and in engineering science. The authors’ objective is two-fold: first, to introduce the student to the theory of structures (one- and two-dimensional) as ...

  20. Decadal variations in groundwater quality

    DEFF Research Database (Denmark)

    Jessen, Søren; Postma, Dieke; Thorling, Lærke

    2017-01-01

    Twenty-five years of groundwater quality monitoring in a sandy aquifer beneath agricultural fields showed large temporal and spatial variations in major ion groundwater chemistry, which were linked closely to the nitrate (NO3) content of agricultural recharge. Between 1988 and 2013, the NO3 content...... loading. Agriculture thus is an important determinant of major ion groundwater chemistry. Temporal and spatial variations in the groundwater quality were simulated using a 2D reactive transport model, which combined effects of the historical NO3 leaching and denitrification, with dispersive mixing...

  1. Structure variations of carbonizing lignin

    International Nuclear Information System (INIS)

    Otani, C.; Polidoro, H.A.; Otani, S.; Craievich, A.F.

    1984-01-01

    The studied lignin is a by-product of the process of ethanol production from eucaliptus. It was heat-treated under inert atmosphere conditions at increasing temperatures from 300C up to 2400C. The structural variations were studied by wide-angle X-ray diffraction, small-angle X-ray scattering and infrared absorption spectroscopy. The bulk and 'real' density of the compacted materials have also been determined as functions of the final temperature. These experimental results enabled us to establish a mechanism of structure variation based on the formation of a turbostratic graphite-like and porous structure within the initially amorphous lignin matrix. (Author) [pt

  2. [Study of the variations in level of fecal contamination of waste water treated at the Charguia purification plant].

    Science.gov (United States)

    Trad, M; Alouini, Z

    1988-01-01

    The quantitative study of bacterian contamination and its variations versus time has been investigated in waste water treated at Charguia sewage treatment plant. In this work we have described the daily and seasonal variations of faecal contamination test germs. The study of daily variations shows that the station entrence numbers of germs may show rapid but not great changes. In the study of seasonal variations, the autumn-spring comparison alone has proved important variations.

  3. Seasonal variations in sleep disorders of nurses.

    Science.gov (United States)

    Chang, Yuanmay; Lam, Calvin; Chen, Su-Ru; Sithole, Trevor; Chung, Min-Huey

    2017-04-01

    To investigate the difference between nurses and the general population regarding seasonal variations in sleep disorders during 2004-2008. The effects of season and group interaction on sleep disorders with regard to different comorbidities were also examined. Studies on seasonal variations in sleep disorders were mainly conducted in Norway for the general population. Furthermore, whether different comorbidities cause seasonal variations in sleep disorders in nurses remains unknown. A retrospective study. Data from the Taiwan National Health Insurance Research Database were used in generalised estimating equation Poisson distribution models to investigate the differences in sleep disorders between nurses and the general population diagnosed with sleep disorders (each n = 7643) as well as the interaction effects of sleep disorders between the groups with respect to different seasons. Furthermore, the interaction effects between groups and seasons on sleep disorders in the subgroups of comorbid anxiety disorders and depressive disorders were studied. Both the nurses and the general population had fewer outpatient visits for sleep disorders in winter than in other seasons. The nurses had fewer outpatient visits for sleep disorders than the general population did in each season. The nurses had more outpatient visits for sleep disorders in winter than in summer compared with the general population in the comorbid depressive disorder subgroup but not in the comorbid anxiety disorder subgroup. Nurses and the general population exhibited similar seasonal patterns of sleep disorders, but nurses had fewer outpatient visits for sleep disorders than the general population did in each season. For nurses with comorbid depressive disorders, outpatient visits for sleep disorders were more numerous in winter than in summer, potentially because nurses with comorbid depressive disorders are affected by shorter daylight exposure during winter. Depression and daylight exposure may

  4. Regional variation in incidence of primary total hip arthroplasties and revisions in Denmark, 1996-2002

    DEFF Research Database (Denmark)

    Pedersen, Alma Becic; Johnsen, Søren Paaske; Overgaard, Søren

    2005-01-01

    We examined incidence rates (IR) of total hip arthroplasty (THA) in Denmark according to county and type of hospital, and investigated possible factors associated with any variations.......We examined incidence rates (IR) of total hip arthroplasty (THA) in Denmark according to county and type of hospital, and investigated possible factors associated with any variations....

  5. Derivation of Schwinger variational principles

    International Nuclear Information System (INIS)

    Szmytkowski, R.

    2003-01-01

    We present systematic derivations of bilinear and fractional Schwinger variational principles for matrix elements of a generalized transition operator in the context of quantum mechanical potential scattering. The employed method is based on a generalization of the method of Lagrange multipliers

  6. Variation of elements in nature

    International Nuclear Information System (INIS)

    Venkatavaradan, V.S.

    1977-01-01

    A review is made of nuclear reactions and other physical processes during the formations of planets, leading to the existing elemental and isotope variation. Thermonuclear fusion, radioactive decay, nuclear reactions caused by cosmic rays, man-made isotopes as some of the causes are discussed in details

  7. Symmetries and variation of spectra

    OpenAIRE

    Bhatia, Rajendra; Elsner, Ludwig

    1992-01-01

    An interesting class of matrices is shown to have the property that the spectrum of each of its elements is invariant under multiplication by p-th roots of unity. For this class and tor a class of Hamiltonian matrices improved spectral variation bounds are obtained.

  8. Linking numbers and variational method

    International Nuclear Information System (INIS)

    Oda, I.; Yahikozawa, S.

    1989-09-01

    The ordinary and generalized linking numbers for two surfaces of dimension p and n-p-1 in an n dimensional manifold are derived. We use a variational method based on the properties of topological quantum field theory in order to derive them. (author). 13 refs, 2 figs

  9. Morphological variation of Stromatella monostromatica

    Science.gov (United States)

    Nielsen, Ruth

    1988-09-01

    Thirty two isolates of Stromatella monostromatica (Dangeard) Kornmann were studied in unialgal culture; extensive morphological variation was documented. The shape of bicellular germlings and development of young plants were similar for all isolates which had globular sporangia. These features are, therefore, the most important diagnostic characteristics of the species. The widespread distribution of S. monostromatica suggests that this is a cosmopolitan species.

  10. On quadratic variation of martingales

    Indian Academy of Sciences (India)

    starting point for the development of stochastic calculus for continuous semimartingales without bringing in any results from general theory of processes (see [5]). The almost sure convergence of Qn t to 〈M,M〉t also gives a pathwise formula for the quadratic variation of a continuous local martingale. It also directly shows that ...

  11. On quadratic variation of martingales

    Indian Academy of Sciences (India)

    On quadratic variation of martingales. 459. The proof relied on the theory of stochastic integration. Subsequently, in Karandikar. [4], the formula was derived using only Doob's maximal inequality. Thus this could be the starting point for the development of stochastic calculus for continuous semimartingales without bringing in ...

  12. Evolutionary significance of epigenetic variation

    NARCIS (Netherlands)

    Richards, C.L.; Verhoeven, K.J.F.; Bossdorf, O.; Wendel, J.F.; Greilhuber, J.; Dolezel, J.; Leitch, I.J.

    2012-01-01

    Several chapters in this volume demonstrate how epigenetic work at the molecular level over the last few decades has revolutionized our understanding of genome function and developmental biology. However, epigenetic processes not only further our understanding of variation and regulation at the

  13. Geoelectric investigation to delineate groundwater potential and ...

    Indian Academy of Sciences (India)

    Geoelectric investigation to delineate groundwater potential and recharge zones in Suki river basin, ... future, investigation was carried out with the help of geophysical indicators. Vertical electrical sounding studies were conducted at 17 ..... This will aid in understanding the spatial variation of these parameters to demar-.

  14. Nuclear level density variation with angular momentum induced shape transition

    International Nuclear Information System (INIS)

    Aggarwal, Mamta

    2016-01-01

    Variation of Nuclear level density (NLD) with the excitation energy and angular momentum in particular has been a topic of interest in the recent past and there have been continuous efforts in this direction on the theoretical and experimental fronts but a conclusive trend in the variation of nuclear level density parameter with angular momentum has not been achieved so far. A comprehensive investigation of N=68 isotones around the compound nucleus 119 Sb from neutron rich 112 Ru (Z=44) to neutron deficient 127 Pr (Z= 59) nuclei is presented to understand the angular momentum induced variations in inverse level density parameter and the possible influence of deformation and structural transitions on the variations on NLd

  15. Output power variations in ND:YAG laser hosts

    Energy Technology Data Exchange (ETDEWEB)

    Maupin, W.B. II

    1976-12-01

    Seemingly identical Nd:YAG laser rods often exhibit significant variations in output power. The purpose of this report is to investigate the possible cause or causes for the performance variations in Nd:YAG laser rods. The fundamental chemical and crystal growth characteristics of Nd:YAG are reviewed. The spectroscopy of Nd:YAG is discussed with emphasis on the laser transition. The more common spectroscopic parameters are defined and the important relationships between them derived. Expressions relating the laser performance of cw and Q-switched systems to the host parameters are developed and the important parameters are discussed. Possible energy transfer mechanisms to account for performance variations are presented and evaluated. It is proposed that concentration variations are primarily responsible for laser performance fluctuations and a method for obtaining experimental verification is outlined.

  16. Y-Chromosome variation in hominids: intraspecific variation is limited to the polygamous chimpanzee.

    Directory of Open Access Journals (Sweden)

    Gabriele Greve

    Full Text Available BACKGROUND: We have previously demonstrated that the Y-specific ampliconic fertility genes DAZ (deleted in azoospermia and CDY (chromodomain protein Y varied with respect to copy number and position among chimpanzees (Pan troglodytes. In comparison, seven Y-chromosomal lineages of the bonobo (Pan paniscus, the chimpanzee's closest living relative, showed no variation. We extend our earlier comparative investigation to include an analysis of the intraspecific variation of these genes in gorillas (Gorilla gorilla and orangutans (Pongo pygmaeus, and examine the resulting patterns in the light of the species' markedly different social and mating behaviors. METHODOLOGY/PRINCIPAL FINDINGS: Fluorescence in situ hybridization analysis (FISH of DAZ and CDY in 12 Y-chromosomal lineages of western lowland gorilla (G. gorilla gorilla and a single lineage of the eastern lowland gorilla (G. beringei graueri showed no variation among lineages. Similar findings were noted for the 10 Y-chromosomal lineages examined in the Bornean orangutan (Pongo pygmaeus, and 11 Y-chromosomal lineages of the Sumatran orangutan (P. abelii. We validated the contrasting DAZ and CDY patterns using quantitative real-time polymerase chain reaction (qPCR in chimpanzee and bonobo. CONCLUSION/SIGNIFICANCE: High intraspecific variation in copy number and position of the DAZ and CDY genes is seen only in the chimpanzee. We hypothesize that this is best explained by sperm competition that results in the variant DAZ and CDY haplotypes detected in this species. In contrast, bonobos, gorillas and orangutans-species that are not subject to sperm competition-showed no intraspecific variation in DAZ and CDY suggesting that monoandry in gorillas, and preferential female mate choice in bonobos and orangutans, probably permitted the fixation of a single Y variant in each taxon. These data support the notion that the evolutionary history of a primate Y chromosome is not simply encrypted in its DNA

  17. Climate variation alters the synchrony of host-parasitoid interactions.

    Science.gov (United States)

    Wetherington, Miles T; Jennings, David E; Shrewsbury, Paula M; Duan, Jian J

    2017-10-01

    Observed changes in mean temperature and increased frequency of extreme climate events have already impacted the distributions and phenologies of various organisms, including insects. Although some research has examined how parasitoids will respond to colder temperatures or experimental warming, we know relatively little about how increased variation in temperature and humidity could affect interactions between parasitoids and their hosts. Using a study system consisting of emerald ash borer (EAB), Agrilus planipennis , and its egg parasitoid Oobius agrili , we conducted environmentally controlled laboratory experiments to investigate how increased seasonal climate variation affected the synchrony of host-parasitoid interactions. We hypothesized that increased climate variation would lead to decreases in host and parasitoid survival, host fecundity, and percent parasitism (independent of host density), while also influencing percent diapause in parasitoids. EAB was reared in environmental chambers under four climate variation treatments (standard deviations in temperature of 1.24, 3.00, 3.60, and 4.79°C), while O .  agrili experiments were conducted in the same environmental chambers using a 4 × 3 design (four climate variation treatments × 3 EAB egg densities). We found that EAB fecundity was negatively associated with temperature variation and that temperature variation altered the temporal egg laying distribution of EAB. Additionally, even moderate increases in temperature variation affected parasitoid emergence times, while decreasing percent parasitism and survival. Furthermore, percent diapause in parasitoids was positively associated with humidity variation. Our findings indicate that relatively small changes in the frequency and severity of extreme climate events have the potential to phenologically isolate emerging parasitoids from host eggs, which in the absence of alternative hosts could lead to localized extinctions. More broadly, these results

  18. Characteristics of seasonal variation and solar activity dependence of the geomagnetic solar quiet daily variation

    Science.gov (United States)

    Shinbori, A.; Koyama, Y.; Nose, M.; Hori, T.

    2017-12-01

    Characteristics of seasonal variation and solar activity dependence of the X- and Y-components of the geomagnetic solar quiet (Sq) daily variation at Memanbetsu in mid-latitudes and Guam near the equator have been investigated using long-term geomagnetic field data with 1-h time resolution from 1957 to 2016. In this analysis, we defined the quiet day when the maximum value of the Kp index is less than 3 for that day. In this analysis, we used the monthly average of the adjusted daily F10.7 corresponding to geomagnetically quiet days. For identification of the monthly mean Sq variation in the X and Y components (Sq-X and Sq-Y), we first determined the baseline of the X and Y components from the average value from 22 to 2 h (LT: local time) for each quiet day. Next, we calculated a deviation from the baseline of the X- and Y-components of the geomagnetic field for each quiet day, and computed the monthly mean value of the deviation for each local time. As a result, Sq-X and Sq-Y shows a clear seasonal variation and solar activity dependence. The amplitude of seasonal variation increases significantly during high solar activities, and is proportional to the solar F10.7 index. The pattern of the seasonal variation is quite different between Sq-X and Sq-Y. The result of the correlation analysis between the solar F10.7 index and Sq-X and Sq-Y shows almost the linear relationship, but the slope and intercept of the linear fitted line varies as function of local time and month. This implies that the sensitivity of Sq-X and Sq-Y to the solar activity is different for different local times and seasons. The local time dependence of the offset value of Sq-Y at Guam and its seasonal variation suggest a magnetic field produced by inter-hemispheric field-aligned currents (FACs). From the sign of the offset value of Sq-Y, it is infer that the inter-hemispheric FACs flow from the summer to winter hemispheres in the dawn and dusk sectors and from the winter to summer hemispheres in

  19. Outdoor radon variation in Romania

    International Nuclear Information System (INIS)

    Simion, Elena; Simion, Florin

    2008-01-01

    Full text: The results of a long-term survey (1992 - 2006) of the variations of outdoor radon concentrations in semi-natural location from Romania are reported in the present paper. Measurements, covering between two and four sessions of the day (morning, afternoon, evening and night), were performed on a daily bases by 37 Environmental Radioactivity Monitoring Stations from National Environmental Radioactivity Survey Network. The method used was based on indirect determination of outdoor radon from aerosol samples collected on glass micro-fibre filters by drawing the air through the filters. The sampling was performed in a fixed place at a height of 2 m above the ground surface. Total beta counting of aerosol samples collected was performed immediately and after 20 hours. Values recorded during the years of continuous measurement indicated the presence of several patterns in the long-term variation of outdoor radon concentration: diurnal, seasonal and annual variation. For diurnal variation, outdoor radon concentration shows a maximum values in the night (early hours) and minimum values by day (in the afternoon). On average, this maximum is a factor of 2 higher than the minimum. Late autumn - beginning of winter maximum and an early spring minimum are characteristic for seasonal patterns. In the long term a seasonal pattern was observed for diurnal variation, with an average diurnal maximum to minimum ratio of 1.33 in winter compared with 3.0 in the summer months. The variations of outdoor radon levels showed little correlation with the uranium concentration of the ground and were attributed to changes in soil moisture content. In dry seasons, because of the low precipitation, the soil was drying out in the summer allowing fractures to develop and radon to migrate easily through the ground. Depending on micro-climatic and geological conditions, outdoor radon average concentrations in different regions of Romania are from 1200 mBq/mc to 13065 mBq/mc. The smallest

  20. Individual diet variation in a marine fish assemblage: Optimal Foraging Theory, Niche Variation Hypothesis and functional identity

    Science.gov (United States)

    Cachera, M.; Ernande, B.; Villanueva, M. C.; Lefebvre, S.

    2017-02-01

    Individual diet variation (i.e. diet variation among individuals) impacts intra- and inter-specific interactions. Investigating its sources and relationship with species trophic niche organization is important for understanding community structure and dynamics. Individual diet variation may increase with intra-specific phenotypic (or "individual state") variation and habitat variability, according to Optimal Foraging Theory (OFT), and with species trophic niche width, according to the Niche Variation Hypothesis (NVH). OFT proposes "proximate sources" of individual diet variation such as variations in habitat or size whereas NVH relies on "ultimate sources" related to the competitive balance between intra- and inter-specific competitions. The latter implies as a corollary that species trophic niche overlap, taken as inter-specific competition measure, decreases as species niche width and individual niche variation increase. We tested the complementary predictions of OFT and NVH in a marine fish assemblage using stomach content data and associated trophic niche metrics. The NVH predictions were tested between species of the assemblage and decomposed into a between- and a within-functional group component to assess the potential influence of species' ecological function. For most species, individual diet variation and niche overlap were consistently larger than expected. Individual diet variation increased with intra-specific variability in individual state and habitat, as expected from OFT. It also increased with species niche width but in compliance with the null expectation, thus not supporting the NVH. In contrast, species niche overlap increased significantly less than null expectation with both species niche width and individual diet variation, supporting NVH corollary. The between- and within-functional group components of the NVH relationships were consistent with those between species at the assemblage level. Changing the number of prey categories used to

  1. On the use of antithetic variates in particle transport problems

    International Nuclear Information System (INIS)

    Milgram, M.S.

    2001-01-01

    The possible use of antithetic variates as a method of variance reduction in particle transport problems is investigated, by performing some numerical experiments. It is found that if variance reduction is not very carefully defined, it is possible, with antithetic variates, to spuriously detect reduction, or not detect true reduction. Once such subtleties are overcome, it is shown that antithetic variates can reduce variance in multidimensional integration up to a point. The phenomenon of spontaneous correlation is defined and identified as the cause of failure. The surprising result that it sometimes pays to track non-contributing particle histories is demonstrated by means of a zero variance integration analogue. The principles developed in the investigation of multi-variable integration are then employed in a simple calculation of energy deposition using the EGS4 computer code. Promising results are obtained for the total energy deposition problem, but the depth/dose problem remains unsolved. Possible means of overcoming the difficulties are suggested

  2. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander

    2013-12-17

    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  3. VARIATIONAL PRINCIPLE FOR PLANETARY INTERIORS

    International Nuclear Information System (INIS)

    Zeng, Li; Jacobsen, Stein B.

    2016-01-01

    In the past few years, the number of confirmed planets has grown above 2000. It is clear that they represent a diversity of structures not seen in our own solar system. In addition to very detailed interior modeling, it is valuable to have a simple analytical framework for describing planetary structures. The variational principle is a fundamental principle in physics, entailing that a physical system follows the trajectory, which minimizes its action. It is alternative to the differential equation formulation of a physical system. Applying the variational principle to the planetary interior can beautifully summarize the set of differential equations into one, which provides us some insight into the problem. From this principle, a universal mass–radius relation, an estimate of the error propagation from the equation of state to the mass–radius relation, and a form of the virial theorem applicable to planetary interiors are derived.

  4. Tidal variations of earth rotation

    Science.gov (United States)

    Yoder, C. F.; Williams, J. G.; Parke, M. E.

    1981-01-01

    The periodic variations of the earths' rotation resulting from the tidal deformation of the earth by the sun and moon were rederived including terms with amplitudes of 0.002 millisec and greater. The series applies to the mantle, crust, and oceans which rotate together for characteristic tidal periods; the scaling parameter is the ratio of the fraction of the Love number producing tidal variations in the moment of inertia of the coupled mantle and oceans (k) to the dimensionless polar moment of inertia of the coupled moments (C). The lunar laser ranging data shows that k/C at monthly and fortnightly frequencies equals 0.99 + or - 0.15 and 0.99 + or - 0.20 as compared to the theoretical value of 0.94 + or - 0.04.

  5. Variational approach in transport theory

    Energy Technology Data Exchange (ETDEWEB)

    Panta Pazos, R. [Nucler Engineering Department, UFRGS, Porto-Alegre (Brazil); Tullio de Vilhena, M. [Institute of Mathematics, UFRGS, Porto-Alegre (Brazil)

    2004-07-01

    In this work we present a variational approach to some methods to solve transport problems of neutral particles. We consider a convex domain X (for example the geometry of a slab, or a convex set in the plane, or a convex bounded set in the space) and we use discrete ordinates quadrature to get a system of differential equations derived from the neutron transport equation. The boundary conditions are vacuum for a subset of the boundary, and of specular reflection for the complementary subset of the boundary. Recently some different approximation methods have been presented to solve these transport problems. We introduce in this work the adjoint equations and the conjugate functions obtained by means of the variational approach. First we consider the general formulation, and then some numerical methods such as spherical harmonics and spectral collocation method. (authors)

  6. Quantitative variation in natural populations

    International Nuclear Information System (INIS)

    Parsons, P.A.

    1975-01-01

    Quantitative variation is considered in natural populations using Drosophila as the example. A knowledge of such variation enables its rapid exploitation in directional selection experiments as shown for scutellar chaeta number. Where evidence has been obtained, genetic architectures are in qualitative agreement with Mather's concept of balance for traits under stabilizing selection. Additive genetic control is found for acute environmental stresses, but not for less acute stresses as shown by exposure to 60 Co-γ rays. D. simulans probably has a narrower ecological niche than its sibling species D. melanogaster associated with lower genetic heterogeneity. One specific environmental stress to which D. simulans is sensitive in nature is ethyl alcohol as shown by winery data. (U.S.)

  7. Coarse Grained Exponential Variational Autoencoders

    KAUST Repository

    Sun, Ke

    2017-02-25

    Variational autoencoders (VAE) often use Gaussian or category distribution to model the inference process. This puts a limit on variational learning because this simplified assumption does not match the true posterior distribution, which is usually much more sophisticated. To break this limitation and apply arbitrary parametric distribution during inference, this paper derives a \\\\emph{semi-continuous} latent representation, which approximates a continuous density up to a prescribed precision, and is much easier to analyze than its continuous counterpart because it is fundamentally discrete. We showcase the proposition by applying polynomial exponential family distributions as the posterior, which are universal probability density function generators. Our experimental results show consistent improvements over commonly used VAE models.

  8. Secular variations of tropospheric ozone

    Energy Technology Data Exchange (ETDEWEB)

    Khrgian, A.KH.

    1988-02-01

    The dependence of secular variations of tropospheric ozone on decreases of temperature and cloud growth in Central Europe is assessed on the basis of Vienna, Paris, and Athens data for 1853-1920. Decreases in ozone content occurring with a certain time lag after major volcanic eruptions (e.g., Krakatoa) are examined. The effect of the Tungusk-meteorite fall on ozone content is also discussed. 13 references.

  9. Secular variations of tropospheric ozone

    Science.gov (United States)

    Khrgian, A. Kh.

    1988-02-01

    The dependence of secular variations of tropospheric ozone on decreases of temperature and cloud growth in Central Europe is assessed on the basis of Vienna, Paris, and Athens data for 1853-1920. Decreases in ozone content occurring with a certain time lag after major volcanic eruptions (e.g., Krakatoa) are examined. The effect of the Tungusk-meteorite fall on ozone content is also discussed.

  10. On Quadratic Variation of Martingales

    Indian Academy of Sciences (India)

    where D ( [ 0 , ∞ ) , R ) denotes the class of real valued r.c.l.l. functions on [ 0 , ∞ ) such that for a locally square integrable martingale ( M t ) with r.c.l.l. paths,. Ψ ( M . ( ) ) = A . ( ). gives the quadratic variation process (written usually as [ M , M ] t ) of ( M t ) . We also show that this process ( A t ) is the unique increasing ...

  11. Variations of posterior vitreous detachment

    OpenAIRE

    Kakehashi, A.; Kado, M.; Akiba, J.; Hirokawa, H.

    1997-01-01

    AIMS—To identify variations in posterior vitreous detachment (PVD) and establish a clinical classification system for PVD.
METHODS—400 consecutive eyes were examined using biomicroscopy and vitreous photography and classified the PVD variations—complete PVD with collapse, complete PVD without collapse, partial PVD with thickened posterior vitreous cortex (TPVC), or partial PVD without TPVC.
RESULTS—In each PVD type, the most frequently seen ocular pathologies were as follows: in complete PVD ...

  12. Deep Feature Consistent Variational Autoencoder

    OpenAIRE

    Hou, Xianxu; Shen, Linlin; Sun, Ke; Qiu, Guoping

    2016-01-01

    We present a novel method for constructing Variational Autoencoder (VAE). Instead of using pixel-by-pixel loss, we enforce deep feature consistency between the input and the output of a VAE, which ensures the VAE's output to preserve the spatial correlation characteristics of the input, thus leading the output to have a more natural visual appearance and better perceptual quality. Based on recent deep learning works such as style transfer, we employ a pre-trained deep convolutional neural net...

  13. Variational nodal transport perturbation theory

    International Nuclear Information System (INIS)

    Laurin-Kovitz, K.F.; Lewis, E.E.

    1996-01-01

    A perturbation method based on the variational nodal method for solving the neutron transport equation is developed for multidimensional geometries. The method utilizes the solution of the corresponding adjoint transport equation to calculate changes in the critical eigenvalue due to cross-section changes. Both first-order and exact perturbation theory expressions are derived. The adjoint solution algorithm has been formulated and incorporated into the variational nodal option of the Argonne National Laboratory DIF3D production code. To demonstrate the efficacy of the methods, perturbation calculations are performed on the three-dimensional Takeda benchmark problems in both Cartesian and hexagonal geometries. The resulting changes in eigenvalue are also obtained by direct calculation with the variational nodal method and compared with the change approximated by the first-order and exact theory expressions from the perturbation method. Exact perturbation results are in excellent agreement with the actual eigenvalue differences calculated in VARIANT. First-order theory holds well for sufficiently small perturbations. The times required for the perturbation calculations are small compared with those expended for the base-forward and adjoint calculations

  14. Longitudinal Variations in Jupiter's Winds

    Science.gov (United States)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  15. A variational approach to Bogoliubov excitations and dynamics of dipolar Bose–Einstein condensates

    International Nuclear Information System (INIS)

    Kreibich, Manuel; Main, Jörg; Wunner, Günter

    2013-01-01

    We investigate the stability properties and the dynamics of Bose–Einstein condensates with axial symmetry, especially with dipolar long-range interaction, using both simulations on grids and variational calculations. We present an extended variational ansatz which is applicable for axial symmetry and show that this ansatz can reproduce the lowest eigenfrequencies of the Bogoliubov spectrum, and also the corresponding eigenfunctions. Our variational ansatz is capable of describing the roton instability of pancake-shaped dipolar condensates for arbitrary angular momenta. After investigating the linear regime we apply the ansatz to determine the dynamics and show how the angular collapse is correctly described within the variational framework. (paper)

  16. Variations in Wood Anatomical Characteristics of Nigerian grown ...

    African Journals Online (AJOL)

    obeche) were investigated to assess the variation pattern of fibre, vessel and ray elements. Test samples were obtained axially from butt, 10%, 30%, 50%, 70% and 90% of merchantable height (MH); and radially from inner wood, middle wood and ...

  17. Multidimensional analysis of Drosophila wing variation in Evolution ...

    Indian Academy of Sciences (India)

    In this study, using Drosophila melanogaster isofemale lines derived from wild flies collected on both slopes of the canyon, we investigated the effect of developmental temperature upon the different components of phenotypic variation of a complex trait: the wing. Combining geometric and traditional morphometrics, we find ...

  18. Genetic variation in three Chersina angulata ( angulate tortoise ...

    African Journals Online (AJOL)

    We investigated genetic variation within and among three populations of Chersina angulata; two in the southwestern Cape (West Coast National Park and Dassen Island) of South Africa and Kleinzee in the northwestern parts of the species' range. Mitochondrial DNA sequences (274 base pairs) of the cytochrome b gene of ...

  19. Anatomical Variation in the Wall Thickness of Wood Fibres of ...

    African Journals Online (AJOL)

    The wall thickness of wood fibres of rubber (Hevea brasiliensis) grown and tapped for latex in south eastern Nigeria were investigated to determine anatomical variation. The rubber trees which were overmature for tapping and keeping were sampled in hierarchical order of plantations, bud classes, trees, discs, cardinal ...

  20. A Variational Approach to Perturbed Discrete Anisotropic Equations

    Directory of Open Access Journals (Sweden)

    Amjad Salari

    2016-01-01

    Full Text Available We continue the study of discrete anisotropic equations and we will provide new multiplicity results of the solutions for a discrete anisotropic equation. We investigate the existence of infinitely many solutions for a perturbed discrete anisotropic boundary value problem. The approach is based on variational methods and critical point theory.

  1. Population-level analysis of gut microbiome variation

    NARCIS (Netherlands)

    Falony, Gwen; Joossens, Marie; Vieira-Silva, Sara; Wang, Jun; Darzi, Youssef; Faust, Karoline; Kurilshchikov, Aleksandr; Bonder, Marc Jan; Valles-Colomer, Mireia; Vandeputte, Doris; Tito, Raul Y.; Chaffron, Samuel; Rymenans, Leen; Verspecht, Chlo; De Sutter, Lise; Lima-Mendez, Gipsi; D'hoe, Kevin; Jonckheere, Karl; Homola, Daniel; Garcia, Roberto; Tigchelaar, Ettje F.; Eeckhaudt, Linda; Fu, Jingyuan; Henckaerts, Liesbet; Zhernakova, Alexandra; Wijmenga, Cisca; Raes, Jeroen

    2016-01-01

    Fecal microbiome variation in the average, healthy population has remained under-investigated. Here, we analyzed two independent, extensively phenotyped cohorts: the Belgian Flemish Gut Flora Project (FGFP; discovery cohort; N = 1106) and the Dutch LifeLines-DEEP study (LLDeep; replication; N =

  2. Spatio-temporal Variations of Abundance, Biomass, and ...

    African Journals Online (AJOL)

    The spatio-seasonal variations of Pseudodiaptomus hessei abundance, biomass and reproductive parameters were investigated in the Grand-Lahou lagoon at five stations during the dry and wet (or rainy) seasons from September 2005 to August 2006. In all sampling stations, abundance and biomass of P. hessei in the dry ...

  3. Seasonal variations in groundwater quality of Valsad District of ...

    African Journals Online (AJOL)

    Groundwater is an important precious natural resource. For optimum utilization of water resources, it is necessary to know both the quality as well as quantity of water. The present investigation is focused on seasonal variation in groundwater quality of Valsad district of south Gujarat (India). Groundwater samples from fifteen ...

  4. Microsatellite variation in Dutch roe deer (Capreolus capreolus) populations

    NARCIS (Netherlands)

    Postma, E.; Hooft, van W.F.; Wieren, van S.E.; Breukelen, van L.

    2001-01-01

    In this study we investigated microsatellite variation in Dutch roe deer (Capreolus capreolus) populations. We used 65 tissue samples from culled animals from three populations (Amsterdamse Waterleidingduinen, National Park Zuid-Kennemerland and Flevopolder). The first two are dune populations and

  5. Assessment of salivary flow rate: biologic variation and measure error.

    NARCIS (Netherlands)

    Jongerius, P.H.; Limbeek, J. van; Rotteveel, J.J.

    2004-01-01

    OBJECTIVE: To investigate the applicability of the swab method in the measurement of salivary flow rate in multiple-handicap drooling children. To quantify the measurement error of the procedure and the biologic variation in the population. STUDY DESIGN: Cohort study. METHODS: In a repeated

  6. The spatial and temporal variations of nematofauna of recovering ...

    African Journals Online (AJOL)

    The spatio-temporal variations in physical sediment characteristics and nematode community assemblages were investigated and compared between a natural, a 10-year reforested, and a degraded Rhizophora mucronata mangrove ecosystem in Gazi Bay, Kenya. PCA showed a clear separation of the degraded site from ...

  7. Variation of basic density and fibre length in Lonchocarpus capassa ...

    African Journals Online (AJOL)

    Within tree radial and axial variations of wood basic density and fibre length of. Lonchocarpus capassa (Rolfe) were investigated using three mature defect free trees from Kilosa District, Tanzania. Samples for determination of wood basic density and fibre length were collected from the butt, the middle and the tip of the

  8. Altitudinal variation of some morphological characters of Scots pine ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the altitudinal variation within and between Scots pine (Pinus sylvestris L.) populations in Turkey using 23 morphological characters. Seeds were collected from 149 open-pollinated parents (trees) from five populations sampled from different altitudes in the natural distribution ...

  9. Variation in seedling morphology of Turkish fir ( Abies ...

    African Journals Online (AJOL)

    In this study, the genetic variation of some seedling characteristics of Turkish fir was investigated. A total of 303 trees were selected from 17 plots and 10 seedlings from each tree were used. Fifteen morphological characteristics were determined, including root collar diameter, seedling height, total needle, bud length and ...

  10. Time Variation of Overtopping Rates applied to WD

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter

    In this investigation the results from a study on optimisation of overtopping ramps (see Kofoed & Frigaard (2000)) are used to compare with the method used by Jakobsen & Frigaard (1999) for simulating the time variation of overtopping rates in the Wave Dragon power simulation software (WDpower)....

  11. Genetic variation of 12 rice cultivars grown in Brunei Darussalam ...

    African Journals Online (AJOL)

    Dell

    2015-03-25

    Mar 25, 2015 ... Quantum yield for B. berminyak were unaffected and it showed the least reduction in growth parameters studied when expose to salinity stress. From both salinity tolerance and genetic variation investigations for these 12 cultivars, it may probably be better to intercross between Arat (moderately tolerant) ...

  12. Morphological variation of Nile tilapia populations from major water ...

    African Journals Online (AJOL)

    In this study, we used a suite of morphological traits to identify strains of Nile tilapia among 425 individuals sampled from the four major water bodies, lakes – Albert, Edward-George, Kyoga and Victoria. Morphological variation was investigated using multivariate approaches including principal component analysis, ...

  13. Towards Modelling Variation in Music as Foundation for Similarity

    NARCIS (Netherlands)

    Volk, A.; de Haas, W.B.; van Kranenburg, P.; Cambouropoulos, E.; Tsougras, C.; Mavromatis, P.; Pastiadis, K.

    2012-01-01

    This paper investigates the concept of variation in music from the perspective of music similarity. Music similarity is a central concept in Music Information Retrieval (MIR), however there exists no comprehensive approach to music similarity yet. As a consequence, MIR faces the challenge on how to

  14. Seasonal variation in phytoplankton in the southern Benguela ...

    African Journals Online (AJOL)

    Pigment indices and satellite imagery were used to investigate the seasonal variation in phytoplankton in the southern Benguela, with the aid of monthly monitoring on two transect lines. Sea surface temperature images revealed the similarity in thermal conditions during autumn, winter and spring, with a broad zone of ...

  15. A variational approach to estimate incompressible fluid flows

    Indian Academy of Sciences (India)

    A variational approach is used to recover fluid motion governed by Stokes and Navier–Stokes equations. Unlike previous approaches where optical flow method is used to track rigid body motion, this new framework aims at investigating incompressible flows using optical flow techniques. We formulate a minimization ...

  16. Spatio-temporal variations in phytoplankton community structure in ...

    African Journals Online (AJOL)

    Spatio-temporal variations of phytoplankton, expressed in terms of species composition and diversity collected at various sampling sites in small water bodies (SWBs) within Lake Victoria basin, Kenya, were investigated monthly from November 2010 to June 2011, in relation to selected physical and chemical water quality ...

  17. Influence of flood variation on seasonal floodplain vegetation ...

    African Journals Online (AJOL)

    This study investigated the influence of flooding variation on floodplain vegetation in the Nxaraga Lagoon seasonal floodplains by sampling community composition and soil nutrient content in 1997, when flood levels were unusually low, and again in 2010 when flood levels were unusually high. In each of the eight ...

  18. Daytime variations in temperature, dissolved oxygen and ph in ...

    African Journals Online (AJOL)

    Daytime variations in temperature, dissolved oxygen concentration and pH were investigated at 3-hourly intervals from 6a.m. to 6 p.m. January had the lowest temperature values, while at noon; September and January had the lowest air and pond water temperature values respectively.Dissolved oxygen increase from 6a.m.

  19. Individual variation in children's reading comprehension across digital text types

    NARCIS (Netherlands)

    Fesel, S.S.; Segers, P.C.J.; Verhoeven, L.T.W.

    2018-01-01

    The present study examined children's digital text comprehension of digital text types linear digital text vs hypertext, with or without graphical navigable overviews. We investigated to what extent individual variation in children's comprehension could be explained by lexical quality (word reading

  20. Seasonal variations in heavy metal concentrations in soil and some ...

    African Journals Online (AJOL)

    In this study, the seasonal variations in concentrations of the heavy metals - As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn - in soil and crops from a farm near the refuse dump site of Obafemi Awolowo University, Ile-Ife, Nigeria were investigated during the two major seasons of Nigeria. This was done to assess the pollution ...

  1. Nucleotide variation at the methionine synthase locus in an ...

    African Journals Online (AJOL)

    Nucleotide variation at the methionine synthase (MetE) locus within and among populations of an endangered forest tree Fokienia hodginsii in Vietnam was investigated in the present study. A total of 12 populations were sampled across Vietnam. The length of the sequenced locus varied from 1567 to 1559 bp. A total of 42 ...

  2. Seasonal variations in aerosol optical properties over China

    Science.gov (United States)

    Yuesi Wang; Jinyuan Xin; Zhanqing Li; Shigong Wang; Pucai Wang; Wei Min Hao; Bryce L. Nordgren; Hongbin Chen; Lili Wang; Yang Sun

    2012-01-01

    Seasonal variations in background aerosol optical depth (AOD) and aerosol type are investigated over various ecosystems in China based upon three years' worth of meteorological data and data collected by the Chinese Sun Hazemeter Network. In most parts of China, AODs are at a maximum in spring or summer and at a minimum in autumn or winter. Minimum values (0.10~0....

  3. Experimental Examination of Temperature Variations in a Hot Runner System

    DEFF Research Database (Denmark)

    Buchardt, Carsten; Jensen, Jan Helleskov; Lauridsen, Carsten Linding

    1999-01-01

    This paper deals with the temperature variations in a hat runner system. By use of FEM-simulations and experiments an investigation is made of the effects of different thermal conductivity's at the supported areas. This effect is analyzed by measuring the temperature and pressure in a hot runner ...

  4. Experimental Examination of Temperature Variations in a Hot Runner System

    DEFF Research Database (Denmark)

    Buchardt, Carsten; Jensen, Jan Helleskov; Lauridsen, Carsten Linding

    1997-01-01

    This paper deals with the temperature variations in a hot runner system. By use of FEM-simulations and experiments an investigation is made of the effects of different thermal conductivity's at the supported areas. This effect is analyzed by measuring the temperature and pressure in a hot runner ...

  5. Variational principles for stochastic fluid dynamics.

    Science.gov (United States)

    Holm, Darryl D

    2015-04-08

    This paper derives stochastic partial differential equations (SPDEs) for fluid dynamics from a stochastic variational principle (SVP). The paper proceeds by taking variations in the SVP to derive stochastic Stratonovich fluid equations; writing their Itô representation; and then investigating the properties of these stochastic fluid models in comparison with each other, and with the corresponding deterministic fluid models. The circulation properties of the stochastic Stratonovich fluid equations are found to closely mimic those of the deterministic ideal fluid models. As with deterministic ideal flows, motion along the stochastic Stratonovich paths also preserves the helicity of the vortex field lines in incompressible stochastic flows. However, these Stratonovich properties are not apparent in the equivalent Itô representation, because they are disguised by the quadratic covariation drift term arising in the Stratonovich to Itô transformation. This term is a geometric generalization of the quadratic covariation drift term already found for scalar densities in Stratonovich's famous 1966 paper. The paper also derives motion equations for two examples of stochastic geophysical fluid dynamics; namely, the Euler-Boussinesq and quasi-geostropic approximations.

  6. REGIONAL VARIATIONS IN CHILD MARRIAGE IN BANGLADESH.

    Science.gov (United States)

    Islam, Md Kamrul; Haque, Md Rabiul; Hossain, Mohammad Bellal

    2016-09-01

    This study aimed to investigate the regional variations in the prevalence of child marriage in Bangladesh with a view to providing recommendations for division-specific policy interventions. Data from the 2011 Bangladesh Demographic and Health Survey were analysed using multivariate logistic regression. Substantial regional variations in child marriage were found in Bangladesh. Rangpur and Khulna had more than four times higher odds of child marriage than Sylhet (4.57 and 4.11 times, respectively). Barisal and Rajshahi had more than three times higher odds of child marriage than Sylhet (3.70 and 3.48 times, respectively). Chittagong and Dhaka had about two times odds of child marriage than Sylhet (1.98 and 2.67 times, respectively), even after controlling for selected socio-demographic, economic and cultural characteristics. Respondent's education, employment status, husband's education and wealth index were inversely associated with the prevalence of child marriage. The policy implications of these findings are discussed in the context of Bangladesh.

  7. Variational principles for stochastic fluid dynamics

    Science.gov (United States)

    Holm, Darryl D.

    2015-01-01

    This paper derives stochastic partial differential equations (SPDEs) for fluid dynamics from a stochastic variational principle (SVP). The paper proceeds by taking variations in the SVP to derive stochastic Stratonovich fluid equations; writing their Itô representation; and then investigating the properties of these stochastic fluid models in comparison with each other, and with the corresponding deterministic fluid models. The circulation properties of the stochastic Stratonovich fluid equations are found to closely mimic those of the deterministic ideal fluid models. As with deterministic ideal flows, motion along the stochastic Stratonovich paths also preserves the helicity of the vortex field lines in incompressible stochastic flows. However, these Stratonovich properties are not apparent in the equivalent Itô representation, because they are disguised by the quadratic covariation drift term arising in the Stratonovich to Itô transformation. This term is a geometric generalization of the quadratic covariation drift term already found for scalar densities in Stratonovich's famous 1966 paper. The paper also derives motion equations for two examples of stochastic geophysical fluid dynamics; namely, the Euler–Boussinesq and quasi-geostropic approximations. PMID:27547083

  8. Cluster-based exposure variation analysis

    Science.gov (United States)

    2013-01-01

    Background Static posture, repetitive movements and lack of physical variation are known risk factors for work-related musculoskeletal disorders, and thus needs to be properly assessed in occupational studies. The aims of this study were (i) to investigate the effectiveness of a conventional exposure variation analysis (EVA) in discriminating exposure time lines and (ii) to compare it with a new cluster-based method for analysis of exposure variation. Methods For this purpose, we simulated a repeated cyclic exposure varying within each cycle between “low” and “high” exposure levels in a “near” or “far” range, and with “low” or “high” velocities (exposure change rates). The duration of each cycle was also manipulated by selecting a “small” or “large” standard deviation of the cycle time. Theses parameters reflected three dimensions of exposure variation, i.e. range, frequency and temporal similarity. Each simulation trace included two realizations of 100 concatenated cycles with either low (ρ = 0.1), medium (ρ = 0.5) or high (ρ = 0.9) correlation between the realizations. These traces were analyzed by conventional EVA, and a novel cluster-based EVA (C-EVA). Principal component analysis (PCA) was applied on the marginal distributions of 1) the EVA of each of the realizations (univariate approach), 2) a combination of the EVA of both realizations (multivariate approach) and 3) C-EVA. The least number of principal components describing more than 90% of variability in each case was selected and the projection of marginal distributions along the selected principal component was calculated. A linear classifier was then applied to these projections to discriminate between the simulated exposure patterns, and the accuracy of classified realizations was determined. Results C-EVA classified exposures more correctly than univariate and multivariate EVA approaches; classification accuracy was 49%, 47% and 52% for EVA (univariate

  9. Stochastic Variational Learning in Recurrent Spiking Networks

    Directory of Open Access Journals (Sweden)

    Danilo eJimenez Rezende

    2014-04-01

    Full Text Available The ability to learn and perform statistical inference with biologically plausible recurrent network of spiking neurons is an important step towards understanding perception and reasoning. Here we derive and investigate a new learning rule for recurrent spiking networks with hidden neurons, combining principles from variational learning and reinforcement learning. Our network defines a generative model over spike train histories and the derived learning rule has the form of a local Spike Timing Dependent Plasticity rule modulated by global factors (neuromodulators conveying information about ``novelty on a statistically rigorous ground.Simulations show that our model is able to learn bothstationary and non-stationary patterns of spike trains.We also propose one experiment that could potentially be performed with animals in order to test the dynamics of the predicted novelty signal.

  10. Origin and Chemical Variation of Brazilian Propolis

    Directory of Open Access Journals (Sweden)

    Antonio Salatino

    2005-01-01

    Full Text Available Propolis is a hive product containing chiefly beeswax and plant-derived substances such as resin and volatile compounds. Propolis has been used as an antiseptic and wound healer since ancient times and interest for the product has increased recently. Probably few plant species contribute as major resin sources. Green propolis derives mainly from vegetative apices of Baccharis dracunculifolia (alecrim plants. However, wide variation detected in the chemical composition suggests contributions from alternative resin plant sources. Predominant components of the resin of green propolis are cinnamic acids, chiefly compounds bearing prenyl groups. Terpenoid compounds, such as sesqui, di and pentacyclic triterpenoids, have been detected in many, but not all, samples investigated. Propolis research has uncovered potentialities of substances previously isolated from plants and has detected constituents of plant origin that would hardly be known otherwise.

  11. Acquiring variation in an artificial language: Children and adults are sensitive to socially conditioned linguistic variation.

    Science.gov (United States)

    Samara, Anna; Smith, Kenny; Brown, Helen; Wonnacott, Elizabeth

    2017-05-01

    Languages exhibit sociolinguistic variation, such that adult native speakers condition the usage of linguistic variants on social context, gender, and ethnicity, among other cues. While the existence of this kind of socially conditioned variation is well-established, less is known about how it is acquired. Studies of naturalistic language use by children provide various examples where children's production of sociolinguistic variants appears to be conditioned on similar factors to adults' production, but it is difficult to determine whether this reflects knowledge of sociolinguistic conditioning or systematic differences in the input to children from different social groups. Furthermore, artificial language learning experiments have shown that children have a tendency to eliminate variation, a process which could potentially work against their acquisition of sociolinguistic variation. The current study used a semi-artificial language learning paradigm to investigate learning of the sociolinguistic cue of speaker identity in 6-year-olds and adults. Participants were trained and tested on an artificial language where nouns were obligatorily followed by one of two meaningless particles and were produced by one of two speakers (one male, one female). Particle usage was conditioned deterministically on speaker identity (Experiment 1), probabilistically (Experiment 2), or not at all (Experiment 3). Participants were given tests of production and comprehension. In Experiments 1 and 2, both children and adults successfully acquired the speaker identity cue, although the effect was stronger for adults and in Experiment 1. In addition, in all three experiments, there was evidence of regularization in participants' productions, although the type of regularization differed with age: children showed regularization by boosting the frequency of one particle at the expense of the other, while adults regularized by conditioning particle usage on lexical items. Overall, results

  12. Variational collocation on finite intervals

    International Nuclear Information System (INIS)

    Amore, Paolo; Cervantes, Mayra; Fernandez, Francisco M

    2007-01-01

    In this paper, we study a set of functions, defined on an interval of finite width, which are orthogonal and which reduce to the sinc functions when the appropriate limit is taken. We show that these functions can be used within a variational approach to obtain accurate results for a variety of problems. We have applied them to the interpolation of functions on finite domains and to the solution of the Schroedinger equation, and we have compared the performance of the present approach with others

  13. Quadratic Variation by Markov Chains

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Horel, Guillaume

    We introduce a novel estimator of the quadratic variation that is based on the the- ory of Markov chains. The estimator is motivated by some general results concerning filtering contaminated semimartingales. Specifically, we show that filtering can in prin- ciple remove the effects of market...... microstructure noise in a general framework where little is assumed about the noise. For the practical implementation, we adopt the dis- crete Markov chain model that is well suited for the analysis of financial high-frequency prices. The Markov chain framework facilitates simple expressions and elegant analyti...

  14. Neodymium isotopic variations in seawater

    Science.gov (United States)

    Piepgras, D. J.; Wasserburg, G. J.

    1980-01-01

    Direct measurement of the isotopic composition of Nd in the Atlantic agree with the Nd content in ferromanganese sediments and differ from the observed amounts in the Pacific samples. These data indicate the existence of distinctive differences in the isotopic composition of Nd in the waters of major oceans; the average values determined from seawater and ferromanganese sediments are considerably lower than in sources with oceanic mantle affinities showing that the REE in the oceans is dominated by continental sources. The Nd isotopic variations in seawater are applied to relate the residence time of Nd and mixing rates between the oceans.

  15. Variation along liquid isomorphs of the driving force for crystallization

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Adrjanowicz, Karolina; Niss, Kristine

    2017-01-01

    at a reference temperature. More general analysis allows interpretation of experimental data for molecular liquids such as dimethyl phthalate and indomethacin, and suggests that the isomorph scaling exponent γ in these cases is an increasing function of density, although this cannot be seen in measurements......We investigate the variation of the driving force for crystallization of a supercooled liquid along isomorphs, curves along which structure and dynamics are invariant. The variation is weak, and can be predicted accurately for the Lennard-Jones fluid using a recently developed formalism and data...

  16. Variational principles for truly three- and four-particle scatterings

    International Nuclear Information System (INIS)

    Dzhibuti, R.I.; Kezerashvili, R.Ya.

    1979-01-01

    Variational principles for the phase of truly three- and four-particle S-scatterings are investigated. The Hulthen, Koon and Schwinger variational principles are formulated, the hyperspherical function basis being used. These principles have been generalized taking account of all the harmonics. Unlike the Hulthen and Koon principles, the Schwinger principle is shown to have some distinguishing properties for truly three-particle collisions. An important feature consists in the fact that no differentiation of the trial function is required, which is an advantage, if the trial functions are predetermined numerically. On the other hand, the necessity of double integration may cause difficulties for application in practice

  17. Circadian variation in 5-hydroxytryptamine levels in human blood.

    Science.gov (United States)

    Sauerbier, I; von Mayersbach, H

    1976-01-01

    This study investigates, on a circadian basis, the variation in blood serotonin for a group of 64 healthy persons (volunteers of a Bundeswehr-Ausbildungskompanie); a pronounced circadian rhythm of 5-HT has been found. The variation in daily absolute levels is influenced by novelty stress; by this we refer to the stress resulting from initial contact between the person sampling blood and the patient. Obviously this diminishes as blood is repeatedly withdrawn from the same individual. Exposure to this situation results in an overall decrease in serotonin levels and a modification of the circadian pattern.

  18. Geographic variation in speed of seed germination in central Oregon ponderosa pine (Pinus ponderosa Dougl. ex Laws.).

    Science.gov (United States)

    John C. Weber; Frank C. Sorensen

    1992-01-01

    Variation in speed of seed germination was investigated among ponderosa pine trees representing 225 locations in central Oregon. Results suggested that at least some of the geographic variation is related to the severity of summer drought. In general, germination speed was greater in locations with shod, drought-limited growing seasons. Levels of geographic variation...

  19. Control, optimisation and calculus of variations

    OpenAIRE

    Colonius, Fritz (Prof.)

    2002-01-01

    Control, optimisation and calculus of variations : COCV = Contrôle, optimisation et calcul des variations / Editorial Board: F. Colonius ... - Vol. 1-7. - Paris : EDP Sciences, SMAI, 1995/96-2002. - (ESAIM) [http://www.emath.fr/cocv/

  20. Amazing variational approach to chemical reactions

    OpenAIRE

    Fernández, Francisco M.

    2009-01-01

    In this letter we analyse an amazing variational approach to chemical reactions. Our results clearly show that the variational expressions are unsuitable for the analysis of empirical data obtained from chemical reactions.

  1. Variational inference & deep learning : A new synthesis

    NARCIS (Netherlands)

    Kingma, D.P.

    2017-01-01

    In this thesis, Variational Inference and Deep Learning: A New Synthesis, we propose novel solutions to the problems of variational (Bayesian) inference, generative modeling, representation learning, semi-supervised learning, and stochastic optimization.

  2. Seasonal variation in pediatric dermatoses

    Directory of Open Access Journals (Sweden)

    Banerjee Sabyasachi

    2010-01-01

    Full Text Available Introduction: The under-five population is a unique and vulnerable component of our society that always demands special attention. Aims: Our present work aimed to study the seasonal variation, age-wise variation and distribution of lesions of common dermatoses of this age group. Materials and Methods: We clinically studied all fresh cases attending the skin OPD of our hospital for one month each from summer, rainy season and winter. Total number of patients was 879. Results: The top six skin diseases in our study were impetigo, miliaria, scabies, furunculosis, seborrheic dermatitis and papular urticaria. On statistical analysis, scabies and seborrheic dermatitis were more prevalent during winter while impetigo, furunculosis and miliaria were more during summer and rainy season. Papular urticaria was more frequent in the rainy season. Seborrheic dermatitis predominantly affected the infants while impetigo, furunculosis, miliaria and popular urticaria were commoner in older age groups. Conclusion: Distribution of lesions of common dermatoses will help diagnose difficult cases and extensive evaluation of the body parts which, by virtue of being commonly affected, are must-examine sites in under-five children.

  3. Homogenization of variational inequalities for obstacle problems

    International Nuclear Information System (INIS)

    Sandrakov, G V

    2005-01-01

    Results on the convergence of solutions of variational inequalities for obstacle problems are proved. The variational inequalities are defined by a non-linear monotone operator of the second order with periodic rapidly oscillating coefficients and a sequence of functions characterizing the obstacles. Two-scale and macroscale (homogenized) limiting variational inequalities are obtained. Derivation methods for such inequalities are presented. Connections between the limiting variational inequalities and two-scale and macroscale minimization problems are established in the case of potential operators.

  4. Importance of Local Structural Variations on Recrystallization

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; Lin, Fengxiang; Zhang, Yubin

    2013-01-01

    Effects of local variations in the deformation microstructure on subsequent recrystallization are discussed and illustrated by three examples. The three examples consider local variations on different length scales and are: 1. Effects of local variations in the deformation microstructure on the f...

  5. Models of Solar Irradiance Variations: Current Status

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Whereas variations on time scales of minutes to hours are due to solar oscillations and granulation, variations on longer time scales are driven by the evolution of the solar surface magnetic field. Here the most recent advances in modelling of solar irradiance variations on time scales longer than a day are ...

  6. Variation of the latissimus dorsi

    Directory of Open Access Journals (Sweden)

    Ishani P Shah

    2014-01-01

    Full Text Available A typical muscle variation of latissimus dorsi - the axillary arch is represented by the muscular or fibromuscular slip detached from the anteroinferior border of the musculus latissimus dorsi passing over the axilla under the axillary fascia crossing the medial side of the brachial plexus to continue as a septum intermusculare mediale brachii distally to the medial epicondyle of humerus. The full extent of the muscle is rarely present. Slips of muscle extend from the latissimus dorsi at the inferior angle of scapula to insert into pectoralis major (Langer, coracobrachilis, biceps or coracoid process forming what is described as a common variant - the muscular axillary arch. We report three cases of variants of latissimus dorsi, one of which has not been reported in the literature before.

  7. Variational identities and Hamiltonian structures

    Science.gov (United States)

    Ma, Wen-Xiu

    2010-03-01

    This report is concerned with Hamiltonian structures of classical and super soliton hierarchies. In the classical case, basic tools are variational identities associated with continuous and discrete matrix spectral problems, targeted to soliton equations derived from zero curvature equations over general Lie algebras, both semisimple and non-semisimple. In the super case, a supertrace identity is presented for constructing Hamiltonian structures of super soliton equations associated with Lie superalgebras. We illustrate the general theories by the KdV hierarchy, the Volterra lattice hierarchy, the super AKNS hierarchy, and two hierarchies of dark KdV equations and dark Volterra lattices. The resulting Hamiltonian structures show the commutativity of each hierarchy discussed and thus the existence of infinitely many commuting symmetries and conservation laws.

  8. Variational identities and Hamiltonian structures

    International Nuclear Information System (INIS)

    Ma Wenxiu

    2010-01-01

    This report is concerned with Hamiltonian structures of classical and super soliton hierarchies. In the classical case, basic tools are variational identities associated with continuous and discrete matrix spectral problems, targeted to soliton equations derived from zero curvature equations over general Lie algebras, both semisimple and non-semisimple. In the super case, a supertrace identity is presented for constructing Hamiltonian structures of super soliton equations associated with Lie superalgebras. We illustrate the general theories by the KdV hierarchy, the Volterra lattice hierarchy, the super AKNS hierarchy, and two hierarchies of dark KdV equations and dark Volterra lattices. The resulting Hamiltonian structures show the commutativity of each hierarchy discussed and thus the existence of infinitely many commuting symmetries and conservation laws.

  9. MDCT evaluation of sternal variations: Pictorial essay

    International Nuclear Information System (INIS)

    Duraikannu, Chary; Noronha, Olma V; Sundarrajan, Pushparajan

    2016-01-01

    Sternal variations and anomalies have been identified in the past during autopsy or cadaveric studies. Recently, an increasing number of minor sternal variations have been reported with the advent of multidetector computed tomography (CT). Although there are many sternal variations that occur with varying appearance and prevalence, most of them are not recognized or are underreported during routine imaging of thorax. Identification of sternal variations is important to differentiate from pathological conditions and to prevent fatal complications prior to sternal interventions like marrow aspiration or acupuncture. This article aims to describe the minor and asymptomatic sternal variations by multidetector CT and their clinical significance

  10. Contributions from Different Sources to Semiannual Variation of Geomagnetic Activity

    Science.gov (United States)

    Lyatskaya, S.; Lyatsky, W.; Tan, A.

    2005-05-01

    Historically, the three possible causes for semiannual variation of geomagnetic activity were proposed: 1) an inclination of the ecliptic plane to the solar equatorial plane (while moving around the Sun, the Earth attains its highest heliospheric latitudes, where solar wind speed increases, in equinoctial months); 2) the semiannual variation of the angle between the Earth's axis and the y-axis in the solar-ecliptic (SE) coordinate system (this angle attains its minimum in equinoctial months that results in increasing the contribution from IMF By in the SE coordinate system to IMF Bz in the solar-magnetospheric coordinate system, which is responsible for geomagnetic activity; this effect is known as the Russell-McPherron effect); and 3) the semiannual variation of solar luminosity of high-latitude conjugate ionospheres (in summer-winter months one of the polar caps is in sunlit conditions while in equinoxes both nightside high-latitude ionospheres are in darkness that is favor for the generation of substorm activity). The last mechanism is not dependent on solar wind conditions while two first mechanisms are dependent. This allowed us to estimate the contributions from these two possible mechanisms to the semiannual variation of geomagnetic activity. For this purpose we investigated the semiannual variation of the Dst index for ten years, 1995-2004. We found that after exclusion of the first mechanism, the amplitude decreases by less than 10%, after excluding the second mechanisms (the Russell-McPherron effect) the amplitude of the semiannual variation decreases by ~ 20%. Although both dependence of solar wind speed on heliospheric latitude and the Russell-McPherron effect are evidently seen in the data, our study showed that these effects contribute in total to the semiannual variation of Dst index not more than 30%.

  11. Variational methods for field theories

    International Nuclear Information System (INIS)

    Ben-Menahem, S.

    1986-09-01

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions

  12. Variational methods for field theories

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Menahem, S.

    1986-09-01

    Four field theory models are studied: Periodic Quantum Electrodynamics (PQED) in (2 + 1) dimensions, free scalar field theory in (1 + 1) dimensions, the Quantum XY model in (1 + 1) dimensions, and the (1 + 1) dimensional Ising model in a transverse magnetic field. The last three parts deal exclusively with variational methods; the PQED part involves mainly the path-integral approach. The PQED calculation results in a better understanding of the connection between electric confinement through monopole screening, and confinement through tunneling between degenerate vacua. This includes a better quantitative agreement for the string tensions in the two approaches. Free field theory is used as a laboratory for a new variational blocking-truncation approximation, in which the high-frequency modes in a block are truncated to wave functions that depend on the slower background modes (Boron-Oppenheimer approximation). This ''adiabatic truncation'' method gives very accurate results for ground-state energy density and correlation functions. Various adiabatic schemes, with one variable kept per site and then two variables per site, are used. For the XY model, several trial wave functions for the ground state are explored, with an emphasis on the periodic Gaussian. A connection is established with the vortex Coulomb gas of the Euclidean path integral approach. The approximations used are taken from the realms of statistical mechanics (mean field approximation, transfer-matrix methods) and of quantum mechanics (iterative blocking schemes). In developing blocking schemes based on continuous variables, problems due to the periodicity of the model were solved. Our results exhibit an order-disorder phase transition. The transfer-matrix method is used to find a good (non-blocking) trial ground state for the Ising model in a transverse magnetic field in (1 + 1) dimensions.

  13. Geomagnetic daily variations in H at Alcantara and Eusebio in the Brazilian equatorial region

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, N.B.; Kane, R.P.; Padilha, A.L.; Costa, J.M. da

    1989-03-01

    Daily variations in H at Alcantara (dip + 3.8) and Eusebio (dip -6.5), two stations in the equatorial electrojet region in Brazil, are compared. The electrojet in NE Brazil exhibits N-S asymmetry. The discrepancy between the daily variation range in H indicates the presence of complicated ionospheric currents in this region and warrants a detailed investigation. (author).

  14. Inter-laboratory variation in DNA damage using a standard comet assay protocol

    DEFF Research Database (Denmark)

    Forchhammer, Lykke; Ersson, Clara; Loft, Steffen

    2012-01-01

    There are substantial inter-laboratory variations in the levels of DNA damage measured by the comet assay. The aim of this study was to investigate whether adherence to a standard comet assay protocol would reduce inter-laboratory variation in reported values of DNA damage. Fourteen laboratories ...

  15. Sources of Non-Conformity in Phonology: Variation and Exceptionality in Modern Hebrew Spirantization

    Science.gov (United States)

    Martinez, Michal Temkin

    2010-01-01

    This dissertation investigates the integration of two sources of non-conformity--exceptionality and variation - in a single phonological system. Exceptionality manifests itself as systematic non-conformity, and variation as partial or variable non-conformity. When both occur within the same phenomenon, this is particularly challenging for the…

  16. Developmental stage of strongyle eggs affects the outcome variations of real-time PCR analysis

    DEFF Research Database (Denmark)

    Andersen, Ulla Vestergaard; Haakansson, I. T.; Roust, Tina

    2013-01-01

    extent developmental stages can affect the variation of diagnostic test results. This study investigated the influence of developmental stages of strongyle eggs on the variation real-time polymerase chain reaction (PCR) results. Mixed species strongyle eggs were obtained from the faeces of a naturally...

  17. Spatial and seasonal variations of the contamination within water body of the Grand Canal, China

    NARCIS (Netherlands)

    Wang, X.L.; Han, Jingyi; Xu, L.G.; Zhang, Q.

    2010-01-01

    To delineate the character of contaminations in the Grand Canal, China, a three-year study (2004-2006) was conducted to investigate variations the water quality in the canal. Results showed that the variation of water quality within the Grand Canal was of there is remarkable spatial and seasonal

  18. Radial variation in fiber length of some lesser used wood species in ...

    African Journals Online (AJOL)

    Variations in fibre length of ten lesser used wood species were investigated. The mean fibre length varied from 1.07mm in Lannea acida to 2.41mm in Sterculia setigera. Four patterns of within tree radial variations in fibre length were observed in the studied species. In pattern one, fibre length increased from the pith to the ...

  19. Unexpectedly high genetic variation in large unisexual clumps of the subdioecious plant Honckenya peploides

    DEFF Research Database (Denmark)

    Sánchez-Vilas, Julia; Philipp, Marianne; Retuerto, Rubén

    2010-01-01

    Honckenya peploides is a subdioecious dune plant that reproduces both sexually and by clonal growth. In northwest Spain this species was found to exhibit an extreme spatial segregation of the sexes, and our objective was to investigate genetic variation in unisexual clumps. Genetic variation was ...

  20. Parents or predators: Examining intraseasonal variation in nest survival for migratory passerine

    Science.gov (United States)

    Robin Hirsch-Jacobson; W. Andrew Cox; Emily E. Tewes; Frank R., III Thompson; John. Faaborg

    2012-01-01

    For birds, risk of nest predation can vary within a breeding season, but few data exist that explain why such variation occurs. We investigated intraseasonal variation of nest survival of the Acadian Flycatcher (Empidonax virescens) in Midwestern forests and tested whether four of the adults' reproductive strategies (clutch size, nest...

  1. Effects of variations in structural parameters on performance of switched parasitic arrays

    CSIR Research Space (South Africa)

    Mofolo, MRO

    2011-09-01

    Full Text Available to model random errors in such parameters. The effects of these variations on the performance of the SPA antenna are investigated using a numerical approach. Mutual coupling between the array elements is taken into consideration. The variations are modelled...

  2. Dust acoustic shock wave generation due to dust charge variation in ...

    Indian Academy of Sciences (India)

    Keywords. Non-adiabatic charge variation; shock wave. Abstract. In a dusty plasma, the non-adiabaticity of the charge variation on a dust grain surface results in an anomalous dissipation. Analytical investigation shows that this results in a small but finite amplitude dust acoustic (DA) wave propagation which is described by ...

  3. Cryptic genetic variation and body size evolution in threespine stickleback.

    Science.gov (United States)

    McGuigan, Katrina; Nishimura, Nicole; Currey, Mark; Hurwit, Dan; Cresko, William A

    2011-04-01

    The role of environment as a selective agent is well-established. Environment might also influence evolution by altering the expression of genetic variation associated with phenotypes under selection. Far less is known about this phenomenon, particularly its contribution to evolution in novel environments. We investigated how environment affected the evolvability of body size in the threespine stickleback (Gasterosteus aculeatus). Gasterosteus aculeatus is well suited to addressing this question due to the rapid evolution of smaller size in the numerous freshwater populations established following the colonization of new freshwater habitats by an oceanic ancestor. The repeated, rapid evolution of size following colonization contrasts with the general observation of low phenotypic variation in oceanic stickleback. We reared an oceanic population of stickleback under high and low salinity conditions, mimicking a key component of the ancestral environment, and freshwater colonization, respectively. There was low genetic variation for body size under high salinity, but this variance increased significantly when fish were reared under low salinity. We therefore conclude that oceanic populations harbor the standing genetic variation necessary for the evolution of body size, but that this variation only becomes available to selection upon colonization of a new habitat. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.

  4. Matter tensor from the Hilbert variational principle

    International Nuclear Information System (INIS)

    Pandres, D. Jr.

    1976-01-01

    We consider the Hilbert variational principle which is conventionally used to derive Einstein's equations for the source-free gravitational field. We show that at least one version of the equivalence principle suggests an alternative way of performing the variation, resulting in a different set of Einstein equations with sources automatically present. This illustrates a technique which may be applied to any theory that is derived from a variational principle and that admits a gauge group. The essential point is that, if one first imposes a gauge condition and then performs the variation, one obtains field equations with source terms which do not appear if one first performs the variation and then imposes the gauge condition. A second illustration is provided by the variational principle conventionally used to derive Maxwell's equations for the source-free electromagnetic field. If one first imposes the Lorentz gauge condition and then performs the variation, one obtains Maxwell's equations with sources present

  5. Structural genomic variation in ischemic stroke

    Science.gov (United States)

    Matarin, Mar; Simon-Sanchez, Javier; Fung, Hon-Chung; Scholz, Sonja; Gibbs, J. Raphael; Hernandez, Dena G.; Crews, Cynthia; Britton, Angela; Wavrant De Vrieze, Fabienne; Brott, Thomas G.; Brown, Robert D.; Worrall, Bradford B.; Silliman, Scott; Case, L. Douglas; Hardy, John A.; Rich, Stephen S.; Meschia, James F.; Singleton, Andrew B.

    2008-01-01

    Technological advances in molecular genetics allow rapid and sensitive identification of genomic copy number variants (CNVs). This, in turn, has sparked interest in the function such variation may play in disease. While a role for copy number mutations as a cause of Mendelian disorders is well established, it is unclear whether CNVs may affect risk for common complex disorders. We sought to investigate whether CNVs may modulate risk for ischemic stroke (IS) and to provide a catalog of CNVs in patients with this disorder by analyzing copy number metrics produced as a part of our previous genome-wide single-nucleotide polymorphism (SNP)-based association study of ischemic stroke in a North American white population. We examined CNVs in 263 patients with ischemic stroke (IS). Each identified CNV was compared with changes identified in 275 neurologically normal controls. Our analysis identified 247 CNVs, corresponding to 187 insertions (76%; 135 heterozygous; 25 homozygous duplications or triplications; 2 heterosomic) and 60 deletions (24%; 40 heterozygous deletions;3 homozygous deletions; 14 heterosomic deletions). Most alterations (81%) were the same as, or overlapped with, previously reported CNVs. We report here the first genome-wide analysis of CNVs in IS patients. In summary, our study did not detect any common genomic structural variation unequivocally linked to IS, although we cannot exclude that smaller CNVs or CNVs in genomic regions poorly covered by this methodology may confer risk for IS. The application of genome-wide SNP arrays now facilitates the evaluation of structural changes through the entire genome as part of a genome-wide genetic association study. PMID:18288507

  6. supplementing conventional site investigation techniques of ...

    African Journals Online (AJOL)

    user

    item costs at the beginning and end of the projects have been obtained from the Ethiopian. Roads Authority. The projects are roads that the. Ethiopian Roads Authority has had to pay variation amounts through the contract because of differences between earthworks quantities predicted from the site investigation and the.

  7. Variations in the origin of inferior phrenic arteries and their relationship to celiac axis variations on CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Aslaner, Ramazan; Pekcevik, Yeliz; Sahin, Hilal [Dept. of Radiology, Tepecik Training and Research Hospital, Izmir (Turkmenistan); Toka, Onur [Dept. of Statistics, Hacettepe University, Ankara (Turkmenistan)

    2017-04-15

    Knowing the origin of the inferior phrenic artery (IPA) is important prior to surgical interventions and interventional radiological procedures related to IPA. We aimed to identify variations in the origin of IPA and to investigate the relationship between the origin of IPA and celiac axis variations using computed tomography angiography (CTA). The CTA images of 1000 patients (737 male and 263 female, the mean age 60, range 18–94 years) were reviewed in an analysis of IPA and celiac axis variations. The origin of IPA was divided into two groups, those originating as a common trunk and those originating independently without a truncus. The relationship between the origin of IPA and celiac axis variation was analyzed using Pearson's chi-square test. Both IPAs originated from a common trunk in 295 (29.5%) patients. From which the majority of the common trunk originated from the aorta. Contrastingly, the inferior phrenic arteries originated from different origins in 705 (70.5%) patients. The majority of the right inferior phrenic artery (RIPA) and the left inferior phrenic artery (LIPA) originated independently from the celiac axis. Variation in the celiac axis were detected in 110 (11%) patients. The origin of IPA was found to be significantly different in the presence of celiac axis variation. The majority of IPA originated from the aorta in patients with a common IPA trunk, while the majority of RIPA and LIPA originating from the celiac axis in patients without a common IPA trunk. Thus, the origin of IPA may widely differ in the presence of celiac axis variation.

  8. Variations in the origin of inferior phrenic arteries and their relationship to celiac axis variations on CT angiography

    International Nuclear Information System (INIS)

    Aslaner, Ramazan; Pekcevik, Yeliz; Sahin, Hilal; Toka, Onur

    2017-01-01

    Knowing the origin of the inferior phrenic artery (IPA) is important prior to surgical interventions and interventional radiological procedures related to IPA. We aimed to identify variations in the origin of IPA and to investigate the relationship between the origin of IPA and celiac axis variations using computed tomography angiography (CTA). The CTA images of 1000 patients (737 male and 263 female, the mean age 60, range 18–94 years) were reviewed in an analysis of IPA and celiac axis variations. The origin of IPA was divided into two groups, those originating as a common trunk and those originating independently without a truncus. The relationship between the origin of IPA and celiac axis variation was analyzed using Pearson's chi-square test. Both IPAs originated from a common trunk in 295 (29.5%) patients. From which the majority of the common trunk originated from the aorta. Contrastingly, the inferior phrenic arteries originated from different origins in 705 (70.5%) patients. The majority of the right inferior phrenic artery (RIPA) and the left inferior phrenic artery (LIPA) originated independently from the celiac axis. Variation in the celiac axis were detected in 110 (11%) patients. The origin of IPA was found to be significantly different in the presence of celiac axis variation. The majority of IPA originated from the aorta in patients with a common IPA trunk, while the majority of RIPA and LIPA originating from the celiac axis in patients without a common IPA trunk. Thus, the origin of IPA may widely differ in the presence of celiac axis variation

  9. Prevalence, molecular epidemiology and intra-hospital acquisition of Klebsiella pneumoniae strains producing carbapenemases in an Italian teaching hospital from January 2015 to September 2016.

    Science.gov (United States)

    Bartolini, Andrea; Basso, Monica; Franchin, Elisa; Menegotto, Nicola; Ferrari, Anna; De Canale, Ettore; Andreis, Samantha; Scaggiante, Renzo; Stefani, Stefania; Palù, Giorgio; Parisi, Saverio Giuseppe

    2017-06-01

    We described Klebsiella pneumoniae producing carbapenemase (CPKP) spread from 01/01/2015 to 13/09/16 in a tertiary level hospital. The first positive surveillance rectal swab (SRS) or clinical sample (CS) collected in the medical department (MD), surgical department (SD) and intensive care department (ICD) were included in the study. A validated in-house Real-Time PCR method was used to detect carbapenemases; multilocus sequence typing (MLST) was used for further characterization of the strains. 21535 patients were included: 213 CPKP strains from surveillance rectal swab (SRS) and 98 from clinical samples (CS) were collected. The percentage of CPKP detected in SRS with respect to CS increased in the medical MD from 2015 to 2016 (p=0.01) and in ICD from 2012 to 2015 (p=0.0001), while it decreased in SD from 2014 to 2016 (p=0.003); 68.5% of the positive SRS had a previous negative SRS; CPKP was more frequently identified in CS than in SRS in MD. Twelve strains harboured more than one carbapenemase gene. Many other species harbouring a carbapenemase gene were collected. MDs need more inclusive surveillance criteria. The late detection of positive SRS underlined the risk of colonization during hospitalization. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. Seasonal Variations of Stratospheric Age Spectra in GEOSCCM

    Science.gov (United States)

    Li, F.; Waugh, D. W.; Douglass, A. R.; Pawson, S.; Newman, P. A.; Stolarski, R. S.; Strahan, S. E.

    2012-12-01

    The stratospheric age spectrum is the probability distribution function of the transit times since a stratospheric air parcel had last contact with a tropospheric boundary region. The age spectrum provides valuable information on stratospheric transport timescales such as the mean age, modal age, spectral width, and stratospheric decay rate. However, knowledge of the age spectrum's seasonal variability is very limited. In this study, we investigate the seasonal variations of stratospheric age spectra using the pulse tracer method in the Goddard Earth Observing System Chemistry Climate Model (GEOSCCM). The differences between the age spectrum and the Boundary Impulse Response (BIR), which is the direct product of the pulse tracer method, are clarified. We introduce a simplified method to reconstruct seasonally varying age spectra from seasonally varying BIRs. Age spectra in the GEOSCCM have significant seasonal variations throughout the stratosphere. The largest seasonal changes occur in the lowermost and lower stratosphere and the subtropical overworld. Up to 40% differences between the individual month and annually averaged mean age are commonly found in these regions. The modal ages and spectral shapes demonstrate even bigger changes in the polar stratosphere. The seasonal variations of the age spectra reflect the seasonal evolution and relative importance of the slow Brewer-Dobson circulation and the fast isentropic mixing. The seasonal and interannual variations of the BIRs are also investigated. Our results clearly show that computing an ensemble of seasonally dependent BIRs is necessary in order to capture the seasonal and annual mean properties of the stratospheric age spectra.

  11. Temporal Variation in Single-Cell Power-Law Rheology Spans the Ensemble Variation of Cell Population.

    Science.gov (United States)

    Cai, PingGen; Takahashi, Ryosuke; Kuribayashi-Shigetomi, Kaori; Subagyo, Agus; Sueoka, Kazuhisa; Maloney, John M; Van Vliet, Krystyn J; Okajima, Takaharu

    2017-08-08

    Changes in the cytoskeletal organization within cells can be characterized by large spatial and temporal variations in rheological properties of the cell (e.g., the complex shear modulus G ∗ ). Although the ensemble variation in G ∗ of single cells has been elucidated, the detailed temporal variation of G ∗ remains unknown. In this study, we investigated how the rheological properties of individual fibroblast cells change under a spatially confined environment in which the cell translational motion is highly restricted and the whole cell shape remains unchanged. The temporal evolution of single-cell rheology was probed at the same measurement location within the cell, using atomic force microscopy-based oscillatory deformation. The measurements reveal that the temporal variation in the power-law rheology of cells is quantitatively consistent with the ensemble variation, indicating that the cell system satisfies an ergodic hypothesis in which the temporal statistics are identical to the ensemble statistics. The autocorrelation of G ∗ implies that the cell mechanical state evolves in the ensemble of possible states with a characteristic timescale. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  12. Genetic variation in resistance to ionizing radiation

    International Nuclear Information System (INIS)

    Ayala, F.J.

    1991-01-01

    We proposed an investigation of genetically-determined individual differences in sensitivity to ionizing radiation. The model organism is Drosophila melanogaster. The gene coding for Cu,Zn superoxide dismutase (SOD) is the target locus, but the effects of variation in other components of the genome that modulate SOD levels are also taken into account. SOD scavenges oxygen radicals generated during exposure to ionizing radiation. It has been shown to protect against ionizing radiation damage to DNA, viruses, bacteria, mammalian cells, whole mice, and Drosophila. Two alleles, S and F, are commonly found in natural populations of D. melanogaster; in addition we have isolated from a natural population ''null'' (CA1) mutant that yields only 3.5% of normal SOD activity. The S, F, and CA1 alleles provide an ideal model system to investigate SOD-dependent radioresistance, because each allele yields different levels of SOD, so that S > F >> CA1. The roles of SOD level in radioresistance are being investigated in a series of experiments that measure the somatic and germ-line effects of increasing doses of ionizing radiation. In addition, we have pursued an unexpected genetic event-namely the nearly simultaneous transformation of several lines homozygous for the SOD ''null'' allele into predominately S lines. Using specifically designed probes and DNA amplification by means of the Tag polymerase chain reaction (PCR) we have shown that (1) the null allele was still present in the transformed lines, but was being gradually replaced by the S allele as a consequence of natural selection; and (2) that the transformation was due to the spontaneous deletion of a 0.68 Kb truncated P-element, the insertion of which is characteristic of the CA1 null allele

  13. Hollow glass waveguides: New variations

    Science.gov (United States)

    Gibson, Daniel Joseph

    This study is an effort to develop new variations on the infrared silver-silver iodide hollow glass waveguide (HGW) with application specific properties. Four variations are presented: a HGW with a long, gradual taper, a HGW with a rectangular cross-section, curved HGW tips and a new all-dielectric hollow waveguide based on photonic bandgap guidance principles. A hollow glass waveguide tapered over its entire length offers ease of coupling at the proximal end and excellent flexibility at the distal end. Waveguides tapered from 1000 to 500 mum and 700 to 500 mum over 1.5 m were fabricated in this study. Compared to similarly sized non-tapered waveguides, laser losses for the tapered guides were high but decreased when bent. This behavior is contrary to that of non-tapered guides and an iterative ray tracing model was also developed to explain the observed loss characteristics of tapered hollow waveguides. Hollow glass waveguides with round profiles do not maintain the polarization state of the delivered radiation to any appreciable degree. HGWs with large- and small-aspect ratio rectangular cross sections were developed and shown to preserve polarization up to 96%, even when bent. The large aspect ratio guide was able to effectively rotate the transmitted polarization when twisted along its axis. Curved distal tips for medical and dental laser applications were developed by removing the low-OH silica fiber from commercially available stainless steel dental tips, and inserting HGWs of various sizes. The optical performances and heating profiles of the various configurations indicate the tips are suitable for certain medical applications, but the minimum bending radius is limited by the mechanical properties of the glass substrate. A small radii bending loss study confirms that propagating modes periodically couple as the radius of curvature is reduced. Through the application of the photonic bandgap (PBG) guidance, hollow waveguides can be made entirely from

  14. How variation between individuals affects species coexistence.

    Science.gov (United States)

    Hart, Simon P; Schreiber, Sebastian J; Levine, Jonathan M

    2016-08-01

    Although the effects of variation between individuals within species are traditionally ignored in studies of species coexistence, the magnitude of intraspecific variation in nature is forcing ecologists to reconsider. Compelling intuitive arguments suggest that individual variation may provide a previously unrecognised route to diversity maintenance by blurring species-level competitive differences or substituting for species-level niche differences. These arguments, which are motivating a large body of empirical work, have rarely been evaluated with quantitative theory. Here we incorporate intraspecific variation into a common model of competition and identify three pathways by which this variation affects coexistence: (1) changes in competitive dynamics because of nonlinear averaging, (2) changes in species' mean interaction strengths because of variation in underlying traits (also via nonlinear averaging) and (3) effects on stochastic demography. As a consequence of the first two mechanisms, we find that intraspecific variation in competitive ability increases the dominance of superior competitors, and intraspecific niche variation reduces species-level niche differentiation, both of which make coexistence more difficult. In addition, individual variation can exacerbate the effects of demographic stochasticity, and this further destabilises coexistence. Our work provides a theoretical foundation for emerging empirical interests in the effects of intraspecific variation on species diversity. © 2016 John Wiley & Sons Ltd/CNRS.

  15. Nonlinear Variation of Parameters Formula for Impulsive Differential Equations with Initial Time Difference and Application

    Directory of Open Access Journals (Sweden)

    Peiguang Wang

    2014-01-01

    Full Text Available This paper establishes variation of parameters formula for impulsive differential equations with initial time difference. As an application, one of the results is used to investigate stability properties of solutions.

  16. Host genome variations and risk of infections during induction treatment for childhood acute lymphoblastic leukaemia

    DEFF Research Database (Denmark)

    Lund, Bendik; Wesolowska-Andersen, Agata; Lausen, Birgitte

    2014-01-01

    Objectives: To investigate association of host genomic variation and risk of infections during treatment for childhood acute lymphoblastic leukaemia (ALL). Methods: We explored association of 34 000 singlenucleotide polymorphisms (SNPs) related primarily to pharmacogenomics and immune function...

  17. A Local Fractional Variational Iteration Method for Laplace Equation within Local Fractional Operators

    Directory of Open Access Journals (Sweden)

    Yong-Ju Yang

    2013-01-01

    Full Text Available The local fractional variational iteration method for local fractional Laplace equation is investigated in this paper. The operators are described in the sense of local fractional operators. The obtained results reveal that the method is very effective.

  18. Genetic Variation in Schizophrenia Liability is Shared With Intellectual Ability and Brain Structure

    NARCIS (Netherlands)

    Bohlken, Marc M; Brouwer, Rachel M; Mandl, René C W; Kahn, René S; Hulshoff Pol, Hilleke E

    2016-01-01

    BACKGROUND: Alterations in intellectual ability and brain structure are important genetic markers for schizophrenia liability. How variations in these phenotypes interact with variance in schizophrenia liability due to genetic or environmental factors is an area of active investigation. Studying

  19. Variation of respiratory syncytial virus and the relation with meteorological factors in different winter seasons.

    NARCIS (Netherlands)

    Meerhoff, T.J.; Paget, W.J.; Kimpen, J.L.; Schellevis, F.

    2009-01-01

    Background: Respiratory syncytial virus (RSV) is the most important viral agent causing severe respiratory disease in infants and children. In temperate climates, RSV activity typically peaks during winter. We have described the seasonal variation in RSV activity and investigated which

  20. State Variation in Medical Imaging: Despite Great Variation, the Medicare Spending Decline Continues.

    Science.gov (United States)

    Rosenkrantz, Andrew B; Hughes, Danny R; Duszak, Richard

    2015-10-01

    The purpose of this study was to assess state-level trends in per beneficiary Medicare spending on medical imaging. Medicare part B 5% research identifiable files from 2004 through 2012 were used to compute national and state-by-state annual average per beneficiary spending on imaging. State-to-state geographic variation and temporal trends were analyzed. National average per beneficiary Medicare part B spending on imaging increased 7.8% annually between 2004 ($350.54) and its peak in 2006 ($405.41) then decreased 4.4% annually between 2006 and 2012 ($298.63). In 2012, annual per beneficiary spending was highest in Florida ($367.25) and New York ($355.67) and lowest in Ohio ($67.08) and Vermont ($72.78). Maximum state-to-state geographic variation increased over time, with the ratio of highest-spending state to lowest-spending state increasing from 4.0 in 2004 to 5.5 in 2012. Spending in nearly all states decreased since peaks in 2005 (six states) or 2006 (43 states). The average annual decrease among states was 5.1% ± 1.8% (range, 1.2-12.2%) The largest decrease was in Ohio. In only two states did per beneficiary spending increase (Maryland, 12.5% average annual increase since 2005; Oregon, 4.8% average annual increase since 2008). Medicare part B average per beneficiary spending on medical imaging declined in nearly every state since 2005 and 2006 peaks, abruptly reversing previously reported trends. Spending continued to increase, however, in Maryland and Oregon. Identification of state-level variation may facilitate future investigation of the potential effect of specific and regional changes in spending on patient access and outcomes.

  1. Task variation during simulated, repetitive, lowintensity work – influence on manifestation of shoulder muscle fatigue, perceived discomfort and upper-body postures

    NARCIS (Netherlands)

    Luger, T.; Bosch, T.; Hoozemans, M.J.M.; de Looze, M.P.; Veeger, H.E.J.

    2015-01-01

    Work-related musculoskeletal disorders are increasing due to industrialisation of work processes. Task variation has been suggested as potential intervention. The objectives of this study were to investigate, first, the influence of task variation on electromyographic (EMG) manifestations of

  2. Task variation during simulated, repetitive, low-intensity work – influence on manifestation of shoulder muscle fatigue, perceived discomfort and upper-body postures

    NARCIS (Netherlands)

    Luger, T.; Bosch, T.; Hoozemans, M.; Looze, M.P. de; Veeger, D.

    2015-01-01

    Work-related musculoskeletal disorders are increasing due to industrialisation of work processes. Task variation has been suggested as potential intervention. The objectives of this study were to investigate, first, the influence of task variation on electromyographic (EMG) manifestations of

  3. LGBTI Variations in Crime Reporting

    Directory of Open Access Journals (Sweden)

    Toby Miles-Johnson

    2013-05-01

    Full Text Available Research shows that people vary in their willingness to report crime to police depending on the type of crime experienced, their gender, age, and their race or ethnicity. Whether or not lesbian, gay, bisexual, transgender, and intersex (LGBTI and heterosexual people vary in their willingness to report crime to the police is not well understood in the extant literature. In this article, I examine variations in LGBTI respondents’ attitudes, subjective norms, and perceived behavioral control on their intentions to report crimes to the police. Drawing on a survey of LGBTI individuals sampled from a Gay Pride community event and online LGBTI community forums (N = 329, I use quantitative statistical methods to examine whether LGBTI people’s beliefs in police homophobia are also directly associated with the behavioral intention to report crime. Overall, the results indicate that LGBTI and heterosexual people differ significantly in their intention to report crime to the police, and that a belief in police homophobia strongly influences LGBTI people’s intention to underreport crime to the police.

  4. PLURILINGUAL COMPETENCE, STYLES AND VARIATION

    Directory of Open Access Journals (Sweden)

    Jyrki Kalliokoski

    2011-01-01

    Full Text Available The paper explores plurilingual competence in respect to language proficiency, language education and pluri- and multilingualism. The notion of communicative competence was introduced by Hymes (1972 as a reaction to chomskyan view of language as an autonomous system. Hymes’ notion of communicative competence originally included plurilingualism. The concept of communicative competence was quickly adopted to applied linguistics but the idea of a linguistic repertoire consisting of the competencies of linguistic varieties was not imported to SLA or language testing. The Hymesian perspective to plurilingualism as an essential dimension of communicative competence was revived in the Common European Framework (CEFR. However,the practice of applying the CEFR has mostly neglected the dimension on plurilingualism and plurilingual competence. The focus in the use of the CEFR has been on the different areas of language skills within one single language at a time, while the application of plurilingual practices has gained very little attention. The Hymesian notion of communicative competence has lived on in the sociolinguistic research tradition, especially within interactional sociolinguistics. The present paper relates the notion of plurilingual competence to its hymesian origin, to recent trends in plurilingual and pluricultural education, and to the sociolinguistic study of style and linguistic variation in multilingual communities. The article uses Finnish L2 data to show how plurilingual competence is used as an interactional resource.From the perspective of language learning, plurilingual competence enables speakers with different linguistic backgrounds to use their shared linguistic repertoire in order to ensure smooth interaction and achieve mutual understanding.

  5. Helicopter Acoustic Flight Test with Altitude Variation and Maneuvers

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Sim, Ben; Stephenson, James; Smith, Charles D.

    2016-01-01

    A cooperative flight test campaign between NASA and the U.S. Army was performed from September 2014 to February 2015. The purposes of the testing were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. This test was performed at three test sites (0, 4000, and 7000 feet above mean sea level) with two aircraft (AS350 SD1 and EH-60L) tested at each site. This report provides an overview of the test, documents the data acquired and describes the formats of the stored data.

  6. Change in lameness risk estimates in piglets due to the modelling of herd-level variation

    DEFF Research Database (Denmark)

    Josiassen, M.K.; Christensen, J.

    1999-01-01

    (HEPS) system database. To further investigate the change in the effect parameter, we performed a simple test to demonstrate the presence of herd-level variation. Finding substantial herd-level variation, we have re-analysed the data with special attention to the herd-level variation, and how to account...... for it. When herd-level variation was not accounted for in the model, a detrimental effect of prior treatment of the sow was seen but this turned into a beneficial effect when we accounted for the herd-level variation. The treatment of sow refers to any therapeutic treatment given to the sow after...... farrowing but before lameness or weaning occurred. This is, therefore, an example where not only the variances but also the effect parameters changed when we accounted for herd-level variation....

  7. Investigation of temperature correction for tire/pavement noise measurements

    Science.gov (United States)

    2010-11-01

    The Volpe Center Acoustics Facility, in support of the Federal Highway Administration, : investigated the influence of temperature on tire/pavement noise in order to provide guidance on correcting for temperature variations in measured sound levels. ...

  8. An Investigation Into the Performance of a Miniature Diesel Engine

    Science.gov (United States)

    Stevenson, P. W.

    1970-01-01

    Reports the procedures and results of a student investigation of the performance of a miniature diesel engine. The experiments include (1) torque measurement, (2) power measurement, and (3) variation of power output with applied load. Bibliography. (LC)

  9. Spatial Distribution and Semiannual Variation of Cold-Dense Plasma Sheet

    Science.gov (United States)

    Bai, Shichen; Shi, Quanqi; Tian, Anmin; Nowada, Motoharu; Degeling, Alexander W.; Zhou, Xu-Zhi; Zong, Qiu-Gang; Rae, I. Jonathan; Fu, Suiyan; Zhang, Hui; Pu, Zuyin; Fazakerly, Andrew N.

    2018-01-01

    The cold-dense plasma sheet (CDPS) plays an important role in the entry process of the solar wind plasma into the magnetosphere. Investigating the seasonal variation of CDPS occurrences will help us better understand the long-term variation of plasma exchange between the solar wind and magnetosphere, but any seasonal variation of CDPS occurrences has not yet been reported in the literature. In this paper, we investigate the seasonal variation of the occurrence rate of CDPS using Geotail data from 1996 to 2015 and find a semiannual variation of the CDPS occurrences. Given the higher probability of solar wind entry under stronger northward interplanetary magnetic field (IMF) conditions, 20 years of IMF data (1996-2015) are used to investigate the seasonal variation of IMF Bz under northward IMF conditions. We find a semiannual variation of IMF Bz, which is consistent with the Russell-McPherron (R-M) effect. We therefore suggest that the semiannual variation of CDPS may be related to the R-M effect.

  10. Intraspecific phytochemical variation shapes community and population structure for specialist caterpillars

    OpenAIRE

    Glassmire, Andrea E.; Jeffrey, Christopher S.; Forister, Matthew L.; Parchman, Thomas L.; Nice, Chris C.; Jahner, Joshua P.; Wilson, Joseph S.; Walla, Thomas R.; Richards, Lora A.; Smilanich, Angela M.; Leonard, Michael D.; Morrison, Colin R.; Simba?a, Wilmer; Salagaje, Luis A.; Dodson, Craig D.

    2016-01-01

    Summary Chemically mediated plant?herbivore interactions contribute to the diversity of terrestrial communities and the diversification of plants and insects. While our understanding of the processes affecting community structure and evolutionary diversification has grown, few studies have investigated how trait variation shapes genetic and species diversity simultaneously in a tropical ecosystem. We investigated secondary metabolite variation among subpopulations of a single plant species, P...

  11. Experimental investigations of the ozone zero phenomenon

    Science.gov (United States)

    Murayama, K.; Matsumura, N.; Taguchi, M.; Katoh, Y.; Teranishi, K.; Suzuki, S.; Itoh, H.

    2009-08-01

    An experimental study is carried out to clarify the mechanism of the ozone zero phenomenon. Temporal variations of both the discharge characteristics and the metallic electrode surface in the ozone generator are investigated by the Lissajous figure method and Auger electron spectroscopy (AES), respectively. The AES results suggest that a number of oxygen atoms penetrate into the stainless-steel electrode owing to the exposure to ozone. Such a surface change would result in the temporal variation of the discharge characteristics of the generator.

  12. Environmental variation partitioned into separate heritable components

    DEFF Research Database (Denmark)

    Ørsted, Michael; Rohde, Palle Duun; Hoffmann, Ary A

    2018-01-01

    Trait variation is normally separated into genetic and environmental components, yet genetic factors also control the expression of environmental variation, encompassing plasticity across environmental gradients and within-environment responses. We defined four components of environmental variation...... functionally validated the effects of a subset of candidate genes affecting each of the four components of environmental variation and also confirmed the genetic and phenotypic correlations obtained from the DGRP in distinct genetic backgrounds. We delineate selection targets associated with environmental...... variation and the constraints acting upon them, providing a framework for evolutionary and applied studies on environmental sensitivity. Based on our results we suggest that the traditional quantitative genetic view of environmental variation and genotype-by-environment interactions needs revisiting....

  13. Procedural facade variations from a single layout

    KAUST Repository

    Bao, Fan

    2013-02-19

    We introduce a framework to generate many variations of a facade design that look similar to a given facade layout. Starting from an input image, the facade is hierarchically segmented and labeled with a collection of manual and automatic tools. The user can then model constraints that should be maintained in any variation of the input facade design. Subsequently, facade variations are generated for different facade sizes, where multiple variations can be produced for a certain size. Computing such new facade variations has many unique challenges, and we propose a new algorithm based on interleaving heuristic search and quadratic programming. In contrast to most previous work, we focus on the generation of new design variations and not on the automatic analysis of the input\\'s structure. Adding a modeling step with the user in the loop ensures that our results routinely are of high quality. © 2013 ACM.

  14. Morphological variation in the girdled

    African Journals Online (AJOL)

    1990-10-18

    Oct 18, 1990 ... calor clinal in nature. This is seen as a prerequisite for any taxonomic decision. Furthennore, the additional material allowed elaboration of the descriptive character set supplied for the species by Mouton (1986). Forty-two specimens from ten localities (Figure 1) were investigated for 15 meristic, 11 two-state ...

  15. Stem anatomy variation in cottonwood

    Science.gov (United States)

    A.N. Foulger; J. Hacskaylo

    1968-01-01

    Investigations of mineral nutrient-tree growth relationships have dealt mainly with associations involving foliage composition, root formation, or volume production of wood. Few studies have been concerned with changes in wood anatomy associated with element deficiency. In 1949 Davis reported that calcium deficiency was accompanied by a reduction of primary tissue and...

  16. MONTHLY VARIATION OF THE PHYSICOCHEMICAL ...

    African Journals Online (AJOL)

    The pH values of the effluent ranged between 4.0-7.8. For most part of the year the pH values were less than 5, suggesting that the effluent is generally slightly acidic. Based on analysis of data acquired, the investigation concluded that effluents from Rimco industries are polluting the Akwu Uru area of Nnewi with ...

  17. q-regular variation and q-difference equations

    International Nuclear Information System (INIS)

    Rehak, Pavel; VItovec, JirI

    2008-01-01

    We introduce the concept of q-regularly varying functions and establish basic properties of such functions. Among other things it is shown that considering regular variation in q-calculus is somehow natural and leads to interesting observations and simplifications compared with classical continuous and discrete theories. The obtained theory is applied to an investigation of asymptotic behavior of solutions to linear second-order q-difference equations

  18. Temporal variation of clear-water scour at compound Abutments

    OpenAIRE

    Aminuddin Ab. Ghani; Reza Mohammadpour

    2016-01-01

    Most of actual abutments in rivers are built on foundation, while there is limited number of study available on the effects of the foundation on the local scour. In this study, temporal variation of local scour around compound abutment was investigated experimentally under clear-water conditions. The results showed that a suitable level of foundation is able to decrease the scour depth and increase scour time during the flood events. The trend of temporal scour depth at compound pier and abut...

  19. Experimental Examination of Temperature Variations in a Hot Runner System

    DEFF Research Database (Denmark)

    Buchardt, Carsten; Jensen, Jan Helleskov; Lauridsen, Carsten Linding

    1999-01-01

    This paper deals with the temperature variations in a hat runner system. By use of FEM-simulations and experiments an investigation is made of the effects of different thermal conductivity's at the supported areas. This effect is analyzed by measuring the temperature and pressure in a hot runner ...... mold. The pressure development is measured in a specially designed 2-cavity hot runner system where temperature differences can be introduced in the two sections. The weight of the products is also measured....

  20. Experimental Examination of Temperature Variations in a Hot Runner System

    DEFF Research Database (Denmark)

    Buchardt, Carsten; Jensen, Jan Helleskov; Lauridsen, Carsten Linding

    1997-01-01

    This paper deals with the temperature variations in a hot runner system. By use of FEM-simulations and experiments an investigation is made of the effects of different thermal conductivity's at the supported areas. This effect is analyzed by measuring the temperature and pressure in a hot runner ...... mold. The pressure development is measured in a specially designed 2-cavity hot runner system where temperature differences can be introduced in the two sections. The weight of the products are also measured....

  1. q-regular variation and q-difference equations

    Energy Technology Data Exchange (ETDEWEB)

    Rehak, Pavel [Institute of Mathematics, Academy of Sciences of the Czech Republic, Zizkova 22, CZ61662 Brno (Czech Republic); VItovec, JirI [Department of Mathematical Analysis, Faculty of Science, Masaryk University Brno, Janackovo NamestI2a, CZ60200 Brno (Czech Republic)], E-mail: rehak@math.muni.cz, E-mail: vitovec@math.muni.cz

    2008-12-12

    We introduce the concept of q-regularly varying functions and establish basic properties of such functions. Among other things it is shown that considering regular variation in q-calculus is somehow natural and leads to interesting observations and simplifications compared with classical continuous and discrete theories. The obtained theory is applied to an investigation of asymptotic behavior of solutions to linear second-order q-difference equations.

  2. Total variation superiorization schemes in proton computed tomography image reconstruction

    OpenAIRE

    Penfold, S. N.; Schulte, R. W.; Censor, Y.; Rosenfeld, A. B.

    2010-01-01

    Purpose: Iterative projection reconstruction algorithms are currently the preferred reconstruction method in proton computed tomography (pCT). However, due to inconsistencies in the measured data arising from proton energy straggling and multiple Coulomb scattering, noise in the reconstructed image increases with successive iterations. In the current work, we investigated the use of total variation superiorization (TVS) schemes that can be applied as an algorithmic add-on to perturbation-resi...

  3. Genetic variation in bovine milk fat composition

    OpenAIRE

    Stoop, W.M.

    2009-01-01

    In her thesis, Stoop shows that there is considerable genetic variation in milk fat composition, which opens opportunities to improve milk fat composition by selective breeding. Short and medium chain fatty acids had high heritabilities, whereas variation due to herd (mainly feed effects) was moderate. Long chain fatty acids had moderate heritabilities, whereas variation due to herd was high. Several genomic regions (QTL) with effect on short and medium chain, long chain, or both types of fat...

  4. HGVA: the Human Genome Variation Archive

    OpenAIRE

    Lopez, Javier; Coll, Jacobo; Haimel, Matthias; Kandasamy, Swaathi; Tarraga, Joaquin; Furio-Tari, Pedro; Bari, Wasim; Bleda, Marta; Rueda, Antonio; Gr?f, Stefan; Rendon, Augusto; Dopazo, Joaquin; Medina, Ignacio

    2017-01-01

    Abstract High-profile genomic variation projects like the 1000 Genomes project or the Exome Aggregation Consortium, are generating a wealth of human genomic variation knowledge which can be used as an essential reference for identifying disease-causing genotypes. However, accessing these data, contrasting the various studies and integrating those data in downstream analyses remains cumbersome. The Human Genome Variation Archive (HGVA) tackles these challenges and facilitates access to genomic...

  5. Large-scale cosmic ray variations caused by variations of the total solar magnetic field

    International Nuclear Information System (INIS)

    Charakhch'yan, A.N.; Charakhch'yan, T.N.; Moskovskij Gosudarstvennyj Univ.

    1983-01-01

    Large-scale cosmic ray (CR) variations caused by variations of the total solar magnetic field (TSMF) are discussed. Three classes of variations: variations connected with TSMF inversion observed in the same CR energy range as 11-year variations; zone modulation observed in the 5-20 GeV energy range and variations connected with appearance of short-range particles in stratosphere during TSMF growth, are considered using the results of CR probe measurements in atmosphere in the vicinity of Murmansk, Alma-Ata and Mirnij (Antarctica). Large lag times of effects for particles of different energies and asymptotic directions, as well as between effects in magnetic fields on the Sun and in CR are the general feature for the variations under consideration. The character of the discussed variations significantly depends on the TSMF direction resulting in the dependence of effects on the particle charge sign and 22-year recurrence period of properties of the observed variations

  6. Variations in injury characteristics among paediatric patients ...

    African Journals Online (AJOL)

    Variations in injury characteristics among paediatric patients following trauma: A retrospective descriptive analysis comparing pre-hospital and in-hospital deaths at Kamuzu Central Hospital, Lilongwe, Malawi.

  7. Extensive Variation in Chromatin States Across Humans

    KAUST Repository

    Kasowski, M.

    2013-10-17

    The majority of disease-associated variants lie outside protein-coding regions, suggesting a link between variation in regulatory regions and disease predisposition. We studied differences in chromatin states using five histone modifications, cohesin, and CTCF in lymphoblastoid lines from 19 individuals of diverse ancestry. We found extensive signal variation in regulatory regions, which often switch between active and repressed states across individuals. Enhancer activity is particularly diverse among individuals, whereas gene expression remains relatively stable. Chromatin variability shows genetic inheritance in trios, correlates with genetic variation and population divergence, and is associated with disruptions of transcription factor binding motifs. Overall, our results provide insights into chromatin variation among humans.

  8. [Influence of a variation potential on photosynthesis in pumpkin seedlings (Cucurbita pepo L.)].

    Science.gov (United States)

    Sukhov, V S; Shesterneva, O N; Surova, L M; Rumiantsev, E A; Vodeneev, V A

    2013-01-01

    The influence of a variation potential on photosynthesis in pumpkin seedlings (Cucurbita pepo L.) was investigated in our work. It was shown that the variation potential induced by cotyledon burning propagates into a leaf. It decreases CO2 assimilation and transpiration as well as increases nonphotochemical quenching. Investigation of isolated chloroplasts showed that lowering of the pH in incubation medium from 6.9-7.2 to 6.5 increases nonphotochemical quenching. It was proposed that lowering of the cytoplasmic pH induced by the variation potential takes place in the photosynthetic response development.

  9. Anatomic Variations of the Paranasal Sinuses on CT Scan Images

    Directory of Open Access Journals (Sweden)

    AR. Talaiepour

    2005-12-01

    Full Text Available Statement of Problem: Variation in paranasal sinus anatomy as shown on computed tomographic scans is of potential significance for it may pose risks during surgery or predispose to certain pathologic conditions.Purpose: The aim of this study was to assess the relative frequency and concurrence of variations in paranasal sinus anatomy in a given population and to compare the results with previous investigations conducted on different populations.Materials and Methods: All patients over 16 years of age referred to Valiasr hospital,Tehran, Iran, with paranasal sinus tomographic scans and a clinical diagnosis of chronic sinusitis were considered for this study. After excluding those with altered anatomy(iatrogenic or pathologic, scans of unaltered patients were meticulously analyzed for variations in sinus anatomy. Findings were recorded on the patient’s data sheet. The distance between the maxillary sinus floor and the alveolar ridge at the level of the 1stmolar was recorded. All findings were analyzed, and tested with Chi square, where applicable.Results: Overall 143 patients were analyzed (48.3% male and 51.7% female. The frequency of major sinus variations was: Agger nasi cell in 56.7%, Haller cell in 3.5%,Onodi cell in 7%, nasal septal deviation in 63%, Concha bullosa in 35%, and dental anomalies in 4.9% of the studied cases. The distance between the upper alveolar ridge and maxillary sinus floor was 0-30mm (mean 12.16 on the right, and 0-52mm (mean 12.20 on the left.Conclusion: The frequency of anatomic variations in sinus anatomy may be related to race and heredity. A lower number of cases in addition to the use of low yield imaging may explain the discrepancies observed between our results and other investigations.The findings of the present study were based on computed tomography.

  10. Frequency variations of discrete cranial traits in major human populations. III. Hyperostotic variations.

    Science.gov (United States)

    Hanihara, T; Ishida, H

    2001-09-01

    Seven discrete cranial traits usually categorised as hyperostotic characters, the medial palatine canal, hypoglossal canal bridging, precondylar tubercle, condylus tertius, jugular foramen bridging, auditory exostosis, and mylohyoid bridging were investigated in 81 major human population samples from around the world. Significant asymmetric occurrences of the bilateral traits were detected in the medial palatine canal and jugular foramen bridging in several samples. Significant intertrait associations were found between some pairs of the traits, but not consistently across the large geographical samples. The auditory exostosis showed a predominant occurrence in males. With the exception of the auditory exostosis and mylohyoid bridging in a few samples, significant sex differences were slight. The frequency distributions of the traits (except for the auditory exostosis) showed some interregional clinality and intraregional discontinuity, suggesting that genetic drift could have contributed to the observed pattern of variation.

  11. Genetic basis of metabolome variation in yeast.

    Directory of Open Access Journals (Sweden)

    Jeffrey S Breunig

    2014-03-01

    Full Text Available Metabolism, the conversion of nutrients into usable energy and biochemical building blocks, is an essential feature of all cells. The genetic factors responsible for inter-individual metabolic variability remain poorly understood. To investigate genetic causes of metabolome variation, we measured the concentrations of 74 metabolites across ~ 100 segregants from a Saccharomyces cerevisiae cross by liquid chromatography-tandem mass spectrometry. We found 52 quantitative trait loci for 34 metabolites. These included linkages due to overt changes in metabolic genes, e.g., linking pyrimidine intermediates to the deletion of ura3. They also included linkages not directly related to metabolic enzymes, such as those for five central carbon metabolites to ira2, a Ras/PKA pathway regulator, and for the metabolites, S-adenosyl-methionine and S-adenosyl-homocysteine to slt2, a MAP kinase involved in cell wall integrity. The variant of ira2 that elevates metabolite levels also increases glucose uptake and ethanol secretion. These results highlight specific examples of genetic variability, including in genes without prior known metabolic regulatory function, that impact yeast metabolism.

  12. Gravity and Height Variations at Medicina, Italy

    Science.gov (United States)

    Bruni, Sara; Zerbini, Susanna; Errico, Maddalena; Santi, Efisio; Wziontek, Hartmut

    2017-04-01

    Since 1996, at the Medicina station, height and gravity variations are monitored continuously by means of GPS, VLBI and superconducting gravimeter (SG) data. Additionally, absolute gravity observations are performed twice a year and environmental parameters, among others water table levels, are regularly acquired. Levelling between the different monuments at the site area is also carried out repeatedly to constrain local ties in the vertical position. Two GPS systems are located very close to each other, and both are in close proximity to the VLBI antenna. Twenty years of data are now available, which allow investigating both long- and short-period height and gravity signals together with their relevant correlations. Natural land subsidence, which is well known to occur in the area, is a major component of the observed long-term behavior; however, non-linear long-period signatures are also present in the time series. On a shorter time scale, fingerprints of the water table seasonal oscillations can be recognized in the data. The Medicina site is characterized by clayey soil subjected to consolidation effects when the water table lowers during summer periods. The pillar on which the SG is installed is especially affected because of its shallow foundation, causing height decreases in the order of 2.5-3 cm for water table lowering of 2 m. This study presents a comparative analysis of the different data sets with the aim of separating mass and deformation contributions in the SG gravity record.

  13. Color Variations in the Sky at Sunset

    Science.gov (United States)

    1997-01-01

    This image of the martian sunset from Sol 24 shows much more color variation than had previously been seen. The blue color near the Sun is not caused by clouds of water ice, but by the martian dust itself. The dust in the atmosphere absorbs blue light, giving the sky its red color, but it also scatters some of the blue light into the area just around the Sun because of its size. The blue color only becomes apparent near sunrise and sunset, when the light has to pass through the largest amount of dust. This image was taken by the Imager for Mars Pathfinder.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  14. Ethnic variation in rhegmatogenous retinal detachments

    Science.gov (United States)

    Chandra, A; Banerjee, P; Davis, D; Charteris, D

    2015-01-01

    Purpose We aimed to investigate the clinical variation of rhegmatogenous retinal detachments (RD) in patients of different ethnicities. Methods Patients presenting with a primary RD from two ethnic groups were recruited from our tertiary referral hospital between August 2010 and December 2012. Patients who self-reported their ethnic origin either as European Caucasian (EC) or South Asian (SA) were included. Exclusion criteria included trauma, previous vitreoretinal procedures, age under 18 years, complicated cataract surgery and the presence of syndromes known to be associated with a high prevalence of RD. Detailed phenotypic data were collected. Descriptive and comparative statistical analyses were undertaken. Results 1269 Patients were recruited. 1173 (92.4%) were EC. Mean age of onset was 58.3 years (EC) and 54.5 years (SA) (P=0.006). 75.3% EC and 58.4% SA were phakic (Plattice retinal degeneration in the affected eye (P=0.003). Refractive myopia was greater in SA patients (mean: −6.1DS) than EC (−4.2DS) (P=0.032). Additionally, SA patients had a greater mean axial length (25.65 mm) than EC (25.06 mm) (P=0.014). No differences were demonstrated in laterality, family history, type of retinal break or macular status. Conclusions SA patients present with RD at an earlier age and have a more severe phenotype than ECs. Future management strategies for RD may need to reflect these differences. PMID:25853394

  15. Inter-regional variations in suicide rates.

    Science.gov (United States)

    Jagodic, Helena Korosec; Agius, Mark; Pregelj, Peter

    2012-09-01

    Suicidal behaviour is a significant public health problem. Suicide alone represents the 10th leading cause of death worldwide. Suicide is a complex phenomenon and may be the result of an interaction of biological, psychological and socioeconomic factors. Although there are many differences in suicide rates between different countries in the world, some studies reported huge differences of suicide rates between different regions within the same country as well. The studies that investigated the regional differences in suicide rates were gathered in the present article. The studies revealed that depression frequently remained unidentified and thus untreated and could contribute to high regional suicide rates. It could be speculated that access to services, which increases the possibility of diagnosis and treatment of mental disorders, could have an impact on regional suicide rates. Thus the availability of services may be relevant in explaining geographical variations in suicide incidence. Many studies reported that suicide was a major public health issue of particular concern among rural populations, which experienced a consistently higher suicide rate than urban areas considering the availability of psychiatric services, was typically less available in rural regions. As suggested in some studies, it seems that socioeconomic factors outweighed climatic factors in explaining regional differences in the suicide rate but further research is needed.

  16. Effects of temperature variation on MOSFET dosimetry

    International Nuclear Information System (INIS)

    Cheung Tsang; Butson, Martin J; Yu, Peter K N

    2004-01-01

    This note investigates temperature effects on dosimetry using a metal oxide semiconductor field effect transistor (MOSFET) for radiotherapy x-ray treatment. This was performed by analysing the dose response and threshold voltage outputs for MOSFET dosimeters as a function of ambient temperature. Results have shown that the clinical semiconductor dosimetry system (CSDS) MOSFET provides stable dose measurements with temperatures varying from 15 deg. C up to 40 deg. C. Thus standard irradiations performed at room temperature can be directly compared to in vivo dose assessments performed at near body temperature without a temperature correction function. The MOSFET dosimeter threshold voltage varies with temperature and this level is dependent on the dose history of the MOSFET dosimeter. However, the variation can be accounted for in the measurement method. For accurate dosimetry, the detector should be placed for approximately 60 s on a patient to allow thermal equilibrium before measurements are taken with the final reading performed whilst still attached to the patient or conversely left for approximately 120 s after removal from the patient if initial readout was measured at room temperature to allow temperature equilibrium to be established. (note)

  17. Union membership variation in Europe

    DEFF Research Database (Denmark)

    Scheuer, Steen

    2011-01-01

    This article investigates covariates of union density in ten West European countries. It adds to previous research by showing that collective bargaining coverage plays a substantial role. Hence future analyses of union density should emphasize the collective bargaining coverage variable, since...... trade unions may influence both the extent of coverage and the content of agreements. Of course, the question of the direction of the causality remains...

  18. How Rainfall Variation Influences Reproductive Patterns of African Savanna Ungulates in an Equatorial Region Where Photoperiod Variation Is Absent.

    Science.gov (United States)

    Ogutu, Joseph O; Owen-Smith, Norman; Piepho, Hans-Peter; Dublin, Holly T

    2015-01-01

    In high temperate latitudes, ungulates generally give birth within a narrow time window when conditions are optimal for offspring survival in spring or early summer, and use changing photoperiod to time conceptions so as to anticipate these conditions. However, in low tropical latitudes day length variation is minimal, and rainfall variation makes the seasonal cycle less predictable. Nevertheless, several ungulate species retain narrow birth peaks under such conditions, while others show births spread quite widely through the year. We investigated how within-year and between-year variation in rainfall influenced the reproductive timing of four ungulate species showing these contrasting patterns in the Masai Mara region of Kenya. All four species exhibited birth peaks during the putative optimal period in the early wet season. For hartebeest and impala, the birth peak was diffuse and offspring were born throughout the year. In contrast, topi and warthog showed a narrow seasonal concentration of births, with conceptions suppressed once monthly rainfall fell below a threshold level. High rainfall in the previous season and high early rains in the current year enhanced survival into the juvenile stage for all the species except impala. Our findings reveal how rainfall variation affecting grass growth and hence herbivore nutrition can govern the reproductive phenology of ungulates in tropical latitudes where day length variation is minimal. The underlying mechanism seems to be the suppression of conceptions once nutritional gains become insufficient. Through responding proximally to within-year variation in rainfall, tropical savanna ungulates are less likely to be affected adversely by the consequences of global warming for vegetation phenology than northern ungulates showing more rigid photoperiodic control over reproductive timing.

  19. How Rainfall Variation Influences Reproductive Patterns of African Savanna Ungulates in an Equatorial Region Where Photoperiod Variation Is Absent

    Science.gov (United States)

    Ogutu, Joseph O.; Owen-Smith, Norman; Piepho, Hans-Peter; Dublin, Holly T.

    2015-01-01

    In high temperate latitudes, ungulates generally give birth within a narrow time window when conditions are optimal for offspring survival in spring or early summer, and use changing photoperiod to time conceptions so as to anticipate these conditions. However, in low tropical latitudes day length variation is minimal, and rainfall variation makes the seasonal cycle less predictable. Nevertheless, several ungulate species retain narrow birth peaks under such conditions, while others show births spread quite widely through the year. We investigated how within-year and between-year variation in rainfall influenced the reproductive timing of four ungulate species showing these contrasting patterns in the Masai Mara region of Kenya. All four species exhibited birth peaks during the putative optimal period in the early wet season. For hartebeest and impala, the birth peak was diffuse and offspring were born throughout the year. In contrast, topi and warthog showed a narrow seasonal concentration of births, with conceptions suppressed once monthly rainfall fell below a threshold level. High rainfall in the previous season and high early rains in the current year enhanced survival into the juvenile stage for all the species except impala. Our findings reveal how rainfall variation affecting grass growth and hence herbivore nutrition can govern the reproductive phenology of ungulates in tropical latitudes where day length variation is minimal. The underlying mechanism seems to be the suppression of conceptions once nutritional gains become insufficient. Through responding proximally to within-year variation in rainfall, tropical savanna ungulates are less likely to be affected adversely by the consequences of global warming for vegetation phenology than northern ungulates showing more rigid photoperiodic control over reproductive timing. PMID:26295154

  20. Mechanism and modelling of source/drain asymmetry variation in 65 nm CMOS devices for SRAM and logic applications

    International Nuclear Information System (INIS)

    Lee, T H; Fang, Y K; Chiang, Y T; Lin, C T; Chen, M S; Cheng, O

    2008-01-01

    The source/drain asymmetry variation of 65 nm CMOS devices for SRAM and logic applications has been investigated in detail. For the first time, we observe that the asymmetry variation is proportional to the inverse of the root square of the device area. In other words, the asymmetry variation should become worse for future advanced CMOS technologies. Fortunately, through the T-CAD simulations and experiments, we find the variation can be improved significantly with the optimization of the poly-gate grain size, extra laser annealing and using a vertical profile poly-gate. Furthermore, the improvement in asymmetry variation leads to a better static noise margin of SRAM