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Sample records for anti-tuberculosis treatment defaulting

  1. Non-Adherence of New Pulmonary Tuberculosis Patients to Anti-Tuberculosis Treatment

    OpenAIRE

    Kulkarni, PY; Akarte, SV; Mankeshwar, RM; Bhawalkar, JS; A. Banerjee; Kulkarni, AD

    2013-01-01

    Background: Non-adherence to anti-tuberculosis (TB) treatment adversely affects treatment success rate. It increases disease morbidity and mortality. Also, it contributes significantly to the development of drug resistance. Aim: To identify risk factors for non-adherence to anti-TB treatment by new pulmonary TB patients. Subjects and Methods: It is a prospective cohort study at 21 TB treatment centres in E ward of Mumbai Municipal Corporation. All sputum smear positive new pulmonary TB patien...

  2. A population-based case-control study of the safety of oral anti-tuberculosis drug treatment during pregnancy

    DEFF Research Database (Denmark)

    Czeizel, A.E.; Rockenbauer, M.; Olsen, J.;

    2001-01-01

    OBJECTIVE: To study the human teratogenic potential of isoniazid and other anti-tuberculosis drug treatment during pregnancy. DESIGN AND SETTING: Cases from a large population-based dataset at the Hungarian Case-Control Surveillance of Congenital Abnormalities, and controls from the National Birth...... OUTCOME MEASURES: Congenital abnormalities in newborn infants and fetuses diagnosed prenatally during the second and third trimesters, and postnatally from birth to the age of one year. RESULTS: Of 38,151 controls, 29 (0.08%) were exposed to anti-tuberculosis drug treatment during pregnancy; the...... Registry, between 1980 and 1996. Information on all oral anti-tuberculosis drug treatments during pregnancy was medically recorded. STUDY PARTICIPANTS: Women who had newborns or fetuses with congenital abnormalities (case group), and women who had babies with no congenital abnormality (control group). MAIN...

  3. Efficacy Of Anti-Tuberculosis Treatment Alone On Resolution Of Tuberculosis Pleural Effusions

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    V S Selvarajah

    2007-12-01

    Full Text Available To determine the degree of resolution in pleuraleffusions treated with anti-tuberculosis treatment alonewithout thoracentesis, 62 eligible adult cases [mean age(SD, 46 (17 yrs; 77% male] of tuberculosis pleuraleffusions treated in two urban-based university teachinghospitals were retrospectively reviewed for changes ineffusion size at 2, 6 and 12 months after initiation oftreatment. The proportions of patients in whomresolution were complete, partial and unchanged were64.5%, 27.4% and 8.1%. Effusions with size smallerthan three tenth of hemithorax were at three-foldincreased likelihood of complete resolution, comparedwith those with larger effusions [Odds ratio (95% CI:3.295 (1.033 to 10.514; p=0.04]. Consideration forthoracentesis is therefore still important in certainpatients.

  4. Prevention of hepatotoxicity due to anti tuberculosis treatment: A novel integrative approach

    Institute of Scientific and Technical Information of China (English)

    Meghna R Adhvaryu; Narsimha M Reddy; Bhasker C Vakharia

    2008-01-01

    AIM: To evaluate the ability of Curcuma longa (CL) and Tinospora cordifolia (TC) formulation to prevent anti-tuberculosis (TB) treatment (ATT) induced hepatotoxicity.METHODS: Patients with active TB diagnosis were randomized to a drug control group and a trial group on drugs plus an herbal formulation.Isoniazid,rifampicin,pyrazinamide and ethambutol for first 2 mo followed by continuation phase therapy excluding Pyrazinamide for 4 mo comprised the anti-tuberculous treatment.Curcumin enriched (25%) CL and a hydro-ethanolic extract enriched (50%) TC 1 g each divided in two doses comprised the herbal adjuvant.Hemogram,bilirubin and liver enzymes were tested initially and monthly till the end of study to evaluate the result.RESULTS: Incidence and severity of hepatotoxicity was significantly lower in trial group (incidence: 27/192 vs 2/316,P < 0.0001).Mean aspartate transaminase (AST) (195.93 ± 108.74 vs 85 ± 4.24,P < 0.0001),alanine transaminase (ALT) (75.74 ± 26.54 vs 41 ±1.41,P < 0.0001) and serum bilirubin (5.4 ± 3.38 vs 1.5± 0.42,P < 0.0001).A lesser sputum positivity ratio at the end of 4 wk (10/67 vs 4/137,P = 0.0068) and decreased incidence of poorly resolved parenchymal lesion at the end of the treatment (9/152 vs 2/278,P = 0.0037) was observed.Improved patient compliance was indicated by nil drop-out in trial vs 10/192 in control group (P < 0.0001).CONCLUSION: The herbal formulation prevented hepatotoxicity significantly and improved the disease outcome as well as patient compliance without any toxicity or side effects.

  5. A Study of the Timing of Death in Patients with Tuberculosis Who Die During Anti-Tuberculosis Treatment

    Directory of Open Access Journals (Sweden)

    Bhavik Patel

    2016-06-01

    Full Text Available Introduction: India has 2.0 million estimated tuberculosis (TB cases per annum with an estimated 280,000 TB related deaths per year. Understanding when in the course of TB treatment patients die is important for determining the type of intervention to be offered and crucially when this intervention should be given. The objectives of the current study were to determine in a large cohort of TB patients in India: - i treatment outcomes including the number who died while on treatment, ii the month of death and iii characteristics associated with and ldquo;early and rdquo; death, occurring in the initial 8 weeks of treatment. Methodology: This was a retrospective study in C.U.Shah Medical College and Hospital in Surendranagar, Gujarat India. A review was performed of treatment cards and medical records of all TB patients (adults and children registered and placed on standardized anti-tuberculosis treatment from January 2007 to April 2012. Results: There were 376 TB patients of whom 41 (11% were known to have died during treatment. Case-fatality was higher in those previously treated (24% and lower in those with extra-pulmonary TB (1%.Most of deaths during anti-tuberculosis treatment were early, with 66% of all patients dying in the first 8 weeks of treatment. Increasing age and new as compared to recurrent TB disease were significantly associated with and ldquo;early death and rdquo;. In this large cohort of TB patients, Most of deaths occurred early after starting anti-TB treatment. Reasons may relate to i the treatment of the disease itself, raising concerns about drug adherence, quality of anti-tuberculosis drugs or the presence of undetected drug resistance and ii co-morbidities, such as HIV/ AIDS and diabetes mellitus, which are known to influence mortality. iii Late stage presentation by patients themselves. More research in this area from prospective and retrospective studies is needed. [Natl J Med Res 2016; 6(2.000: 186-190

  6. Host Immune Responses Differ between M. africanum- and M. tuberculosis-Infected Patients following Standard Anti-tuberculosis Treatment.

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    Leopold D Tientcheu

    2016-05-01

    Full Text Available Epidemiological differences exist between Mycobacterium africanum (Maf- and Mycobacterium tuberculosis (Mtb-infected patients, but to date, contributing host factors have not been characterised. We analysed clinical outcomes, as well as soluble markers and gene expression profiles in unstimulated, and ESAT6/CFP-10-, whole-Maf- and Mtb-stimulated blood samples of 26 Maf- and 49 Mtb-HIV-negative tuberculosis patients before, and after 2 and 6 months of anti-tuberculosis therapy. Before treatment, both groups had similar clinical parameters, but differed in few cytokines concentration and gene expression profiles. Following treatment the body mass index, skinfold thickness and chest X-ray scores showed greater improvement in the Mtb- compared to Maf-infected patients, after adjusting for age, sex and ethnicity (p = 0.02; 0.04 and 0.007, respectively. In addition, in unstimulated blood, IL-12p70, IL12A and TLR9 were significantly higher in Maf-infected patients, while IL-15, IL-8 and MIP-1α were higher in Mtb-infected patients. Overnight stimulation with ESAT-6/CFP-10 induced significantly higher levels of IFN-γ and TNF-α production, as well as gene expression of CCL4, IL1B and TLR4 in Mtb- compared to Maf-infected patients. Our study confirms differences in clinical features and immune genes expression and concentration of proteins associated with inflammatory processes between Mtb- and Maf-infected patients following anti-tuberculosis treatment These findings have public health implications for treatment regimens, and biomarkers for tuberculosis diagnosis and susceptibility.

  7. Default from tuberculosis treatment in Tashkent, Uzbekistan; Who are these defaulters and why do they default?

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    Yuldashova Umida

    2008-07-01

    Full Text Available Abstract Background In Tashkent (Uzbekistan, TB treatment is provided in accordance with the DOTS strategy. Of 1087 pulmonary TB patients started on treatment in 2005, 228 (21% defaulted. This study investigates who the defaulters in Tashkent are, when they default and why they default. Methods We reviewed the records of 126 defaulters (cases and 132 controls and collected information on time of default, demographic factors, social factors, potential risk factors for default, characteristics of treatment and recorded reasons for default. Results Unemployment, being a pensioner, alcoholism and homelessness were associated with default. Patients defaulted mostly during the intensive phase, while they were hospitalized (61%, or just before they were to start the continuation phase (26%. Reasons for default listed in the records were various, 'Refusal of further treatment' (27% and 'Violation of hospital rules' (18% were most frequently recorded. One third of the recorded defaulters did not really default but continued treatment under 'non-DOTS' conditions. Conclusion Whereas patient factors such as unemployment, being a pensioner, alcoholism and homelessness play a role, there are also system factors that need to be addressed to reduce default. Such system factors include the obligatory admission in TB hospitals and the inadequately organized transition from hospitalized to ambulatory treatment.

  8. Sublineages of Mycobacterium tuberculosis Beijing genotype strains and unfavorable outcomes of anti-tuberculosis treatment.

    Science.gov (United States)

    Hang, Nguyen T L; Maeda, Shinji; Keicho, Naoto; Thuong, Pham H; Endo, Hiroyoshi

    2015-05-01

    The influence of Mycobacterium tuberculosis (MTB) lineages/sublineages on unfavorable tuberculosis (TB) treatment outcomes is poorly understood. We investigated the effects of Beijing genotype sublineages and other factors contributing to treatment outcome. Patients newly diagnosed with sputum smear-positive and culture-positive TB in Hanoi, Vietnam, participated in the study. After receiving anti-TB treatment, they were intensively followed up for the next 16 months. MTB isolates collected before treatment were subjected to drug susceptibility testing, and further analyzed to determine MTB (sub) lineages and their clonal similarities. Of 430 patients, 17 had treatment failure and 30 had TB recurrence. Rifampicin resistance was associated with treatment failure {adjusted odds ratio = 6.64 [95% confidence interval (CI), 1.48-29.73]}. The modern Beijing genotype was significantly associated with recurrent TB within 16 months [adjusted hazard ratio = 3.29 (95% CI, 1.17-9.27)], particularly after adjustment for the relevant antibiotic resistance. Human immunodeficiency virus coinfection and severity on chest radiographs were not significantly associated with unfavorable outcomes. Our findings provide further understanding of the influence of MTB strains on unfavorable treatment outcomes. Multiple risk factors should be considered for the optimal management of TB. PMID:25732626

  9. Determinants of poor adherence to anti-tuberculosis treatment in Mumbai, India

    Directory of Open Access Journals (Sweden)

    Suparna Bagchi

    2010-01-01

    Conclusions: An approach, targeting easier access to drugs, an ensured drug supply, effective solutions for travel-related concerns and modification of smoking and alcohol related behaviors are essential for treatment adherence.

  10. Factors Associated with Fatality during the Intensive Phase of Anti-Tuberculosis Treatment

    Science.gov (United States)

    Casals, M.; Caminero, J. A.; García-García, J. M.; Jiménez-Fuentes, M. A.; Medina, J. F.; Millet, J. P.; Ruiz-Manzano, J.; Caylá, J.

    2016-01-01

    Objective To determine the case-fatality rate (CFR) at the end of the intensive phase of tuberculosis (TB) treatment, and factors associated with fatality. Methods TB patients diagnosed between 2006 and 2013 were followed-up during treatment. We computed the CFR at the end of the intensive phase of TB treatment, and the incidence of death per 100 person-days (pd) of follow-up. We performed survival analysis using the Kaplan-Meier method and Cox regression, and calculate hazard ratios (HR) and 95% confidence intervals (CI). Results A total of 5,182 patients were included, of whom 180 (3.5%) died; 87 of these deaths (48.3%) occurred during the intensive phase of treatment, with a CFR of 1.7%. The incidence of death was 0.028/100 pd. The following factors were associated with death during the intensive phase: being >50 years (HR = 36.9;CI:4.8–283.4); being retired (HR = 2.4;CI:1.1–5.1); having visited the emergency department (HR = 3.1;CI:1.2–7.7); HIV infection (HR = 3.4;CI:1.6–7.2); initial standard treatment with 3 drugs (HR = 2.0;CI:1.2–3.3) or non-standard treatments (HR = 2.68;CI:1.36–5.25); comprehension difficulties (HR = 2.8;CI:1.3–6.1); and smear-positive sputum (HR = 2.3-CI:1.0–4.8). Conclusion There is a non-negligible CFR during the intensive phase of TB, whose reduction should be prioritised. The CFR could be a useful indicator for evaluating TB programs. PMID:27487189

  11. Mobile phone text messaging for promoting adherence to anti-tuberculosis treatment: a systematic review protocol

    OpenAIRE

    Nglazi Mweete D; Bekker Linda-Gail; Wood Robin; Hussey Gregory D; Wiysonge Charles S

    2013-01-01

    Abstract Background In 2010, there were approximately 8.8 million incident cases of tuberculosis (TB) worldwide. The treatment of TB is at least six months long and may be complicated by a high pill burden. In addition, TB patients often do not take their medication on schedule simply because they forget. Mobile phone text messaging has the potential to help promote TB treatment adherence. We, therefore, propose to conduct a review of current best evidence for the use of mobile phone text mes...

  12. Mobile phone text messaging for promoting adherence to anti-tuberculosis treatment: a systematic review protocol

    Directory of Open Access Journals (Sweden)

    Nglazi Mweete D

    2013-01-01

    Full Text Available Abstract Background In 2010, there were approximately 8.8 million incident cases of tuberculosis (TB worldwide. The treatment of TB is at least six months long and may be complicated by a high pill burden. In addition, TB patients often do not take their medication on schedule simply because they forget. Mobile phone text messaging has the potential to help promote TB treatment adherence. We, therefore, propose to conduct a review of current best evidence for the use of mobile phone text messaging to promote patient adherence to TB treatment. Methods This is a systematic review of the literature. We will preferably include randomized controlled trials (RCTs. However, non-randomized studies (NRS will be considered if there is an inadequate number of RCTs. We will search PubMed, EMBASE, CINAHL, CENTRAL, Science Citation Index, Africa-Wide Information, and WHOLIS electronic databases for eligible studies available by 30 November 2012 regardless of language or publication status. We will also check reference lists for additional studies, identify abstracts from conference proceedings and communicate with authors for any relevant material. At least two authors will independently screen search outputs, select studies, extract data and assess the risk of bias (using separate criteria for RCTs and NRS; resolving discrepancies by discussion and consensus. We will assess clinical heterogeneity by examining the types of participants, interventions and outcomes in each study and pool studies judged to be clinically homogenous. We will also assess statistical heterogeneity using the chi-square test of homogeneity and quantify it using the I-square statistic. If study results are found to be statistically homogeneous (that is heterogeneity P > 0.1, we will pool them using the fixed-effect meta-analysis. Otherwise, we will use random-effects meta-analysis. We will calculate risk ratios and their corresponding 95% confidence intervals for dichotomous outcomes

  13. Factors associated with default from treatment among tuberculosis patients in nairobi province, Kenya: A case control study

    Directory of Open Access Journals (Sweden)

    Ombeka Victor O

    2011-09-01

    Full Text Available Abstract Background Successful treatment of tuberculosis (TB involves taking anti-tuberculosis drugs for at least six months. Poor adherence to treatment means patients remain infectious for longer, are more likely to relapse or succumb to tuberculosis and could result in treatment failure as well as foster emergence of drug resistant tuberculosis. Kenya is among countries with high tuberculosis burden globally. The purpose of this study was to determine the duration tuberculosis patients stay in treatment before defaulting and factors associated with default in Nairobi. Methods A Case-Control study; Cases were those who defaulted from treatment and Controls those who completed treatment course between January 2006 and March 2008. All (945 defaulters and 1033 randomly selected controls from among 5659 patients who completed treatment course in 30 high volume sites were enrolled. Secondary data was collected using a facility questionnaire. From among the enrolled, 120 cases and 154 controls were randomly selected and interviewed to obtain primary data not routinely collected. Data was analyzed using SPSS and Epi Info statistical software. Univariate and multivariate logistic regression analysis to determine association and Kaplan-Meier method to determine probability of staying in treatment over time were applied. Results Of 945 defaulters, 22.7% (215 and 20.4% (193 abandoned treatment within first and second months (intensive phase of treatment respectively. Among 120 defaulters interviewed, 16.7% (20 attributed their default to ignorance, 12.5% (15 to traveling away from treatment site, 11.7% (14 to feeling better and 10.8% (13 to side-effects. On multivariate analysis, inadequate knowledge on tuberculosis (OR 8.67; 95% CI 1.47-51.3, herbal medication use (OR 5.7; 95% CI 1.37-23.7, low income (OR 5.57, CI 1.07-30.0, alcohol abuse (OR 4.97; 95% CI 1.56-15.9, previous default (OR 2.33; 95% CI 1.16-4.68, co-infection with Human immune

  14. Experiences in anti-tuberculosis treatment in patients with multiple previous treatments and its impact on drug resistant tuberculosis epidemics

    OpenAIRE

    Xu, Biao; Zhao, Qi; Hu, Yi; SHI Ying; Wang, Weibing; Diwan, Vinod K.

    2014-01-01

    Background: Tuberculosis (TB) patients with a history of multiple anti-TB treatments are the ‘neglected’ group to the free anti-TB treatment policy in China.Objective: To understand the experiences of TB patients with multiple previous treatments with regard to bacteriological diagnosis and treatment regimens, especially for second-line anti-TB drugs, and how this might influence the risks of multidrug and extensively drug-resistant TB (M/XDR-TB).Design: A cross-sectional study was conducted ...

  15. Experiences in anti-tuberculosis treatment in patients with multiple previous treatments and its impact on drug resistant tuberculosis epidemics

    Directory of Open Access Journals (Sweden)

    Biao Xu

    2014-08-01

    Full Text Available Background: Tuberculosis (TB patients with a history of multiple anti-TB treatments are the ‘neglected’ group to the free anti-TB treatment policy in China. Objective: To understand the experiences of TB patients with multiple previous treatments with regard to bacteriological diagnosis and treatment regimens, especially for second-line anti-TB drugs, and how this might influence the risks of multidrug and extensively drug-resistant TB (M/XDR-TB. Design: A cross-sectional study was conducted in 10 county/district TB clinics in five provinces of China. The study participants were TB patients that had at least two previous treatment episodes that lasted longer than 1 month each. Face-to-face interviews and drug susceptibility testing (DST were conducted with the consenting participants. Results: A total of 328 TB patients were recruited. The proportion of multidrug-resistant tuberculosis (MDR-TB was 58.2% in the 287 DST-confirmed patients. Forty-two percent of the patients did not complete their first treatment course. About 23.8% of the participants had a history of taking second-line drugs, and more than 77.8% of them were treated in county TB dispensaries where only sputum microscopy was applied. Multivariate analysis found that the use of second-line drugs was significantly associated with frequency of previous treatments (p<0.01, but not with drug resistance profiles of patients. Conclusions: Patients with multiple previous treatments are at extremely high risk of MDR-TB in China. The unregulated use of second-line drugs bring about the threat of XDR-TB epidemic. DST-guided treatment and strict regulations of anti-TB treatment should be assured for the high-risk TB patients for the prevention and control of M/XDR-TB.

  16. Effect of scheduled monitoring of liver function during anti-Tuberculosis treatment in a retrospective cohort in China

    OpenAIRE

    Wu Shanshan; Xia Yinyin; Lv Xiaozhen; Zhang Yuan; Tang Shaowen; Yang Zhirong; Tu Dehua; Deng Peiyuan; Cheng Shiming; Wang Xiaomeng; Yuan Yanli; Liu Feiying; Hu Daiyu; Zhan Siyan

    2012-01-01

    Abstract Background Data on effect of regular liver function monitoring during anti-TB treatment is limited in China. This study aimed to evaluate the effects of scheduled liver function monitoring on identification of asymptomatic liver damage and anti-TB treatment outcomes during anti-TB treatment. Methods A retrospective analysis was performed based on a national-level cohort study. A total of 273 patients developing liver dysfunction were divided into two groups, 111 patients who were dia...

  17. Duration of Anti-Tuberculosis Therapy and Timing of Antiretroviral Therapy Initiation: Association with Mortality in HIV-Related Tuberculosis

    Science.gov (United States)

    Cortes, Claudia P.; Wehbe, Firas H.; McGowan, Catherine C.; Shepherd, Bryan E.; Duda, Stephany N.; Jenkins, Cathy A.; Gonzalez, Elsa; Carriquiry, Gabriela; Schechter, Mauro; Padgett, Denis; Cesar, Carina; Madero, Juan Sierra; Pape, Jean W.; Masys, Daniel R.; Sterling, Timothy R.

    2013-01-01

    Background Antiretroviral therapy (ART) decreases mortality risk in HIV-infected tuberculosis patients, but the effect of the duration of anti-tuberculosis therapy and timing of anti-tuberculosis therapy initiation in relation to ART initiation on mortality, is unclear. Methods We conducted a retrospective observational multi-center cohort study among HIV-infected persons concomitantly treated with Rifamycin-based anti-tuberculosis therapy and ART in Latin America. The study population included persons for whom 6 months of anti-tuberculosis therapy is recommended. Results Of 253 patients who met inclusion criteria, median CD4+ lymphocyte count at ART initiation was 64 cells/mm3, 171 (68%) received >180 days of anti-tuberculosis therapy, 168 (66%) initiated anti-tuberculosis therapy before ART, and 43 (17%) died. In a multivariate Cox proportional hazards model that adjusted for CD4+ lymphocytes and HIV-1 RNA, tuberculosis diagnosed after ART initiation was associated with an increased risk of death compared to tuberculosis diagnosis before ART initiation (HR 2.40; 95% CI 1.15, 5.02; P = 0.02). In a separate model among patients surviving >6 months after tuberculosis diagnosis, after adjusting for CD4+ lymphocytes, HIV-1 RNA, and timing of ART initiation relative to tuberculosis diagnosis, receipt of >6 months of anti-tuberculosis therapy was associated with a decreased risk of death (HR 0.23; 95% CI 0.08, 0.66; P=0.007). Conclusions The increased risk of death among persons diagnosed with tuberculosis after ART initiation highlights the importance of screening for tuberculosis before ART initiation. The decreased risk of death among persons receiving > 6 months of anti-tuberculosis therapy suggests that current anti-tuberculosis treatment duration guidelines should be re-evaluated. PMID:24066096

  18. Treatment default amongst patients with tuberculosis in urban Morocco: predicting and explaining default and post-default sputum smear and drug susceptibility results.

    Directory of Open Access Journals (Sweden)

    Imad Cherkaoui

    Full Text Available SETTING: Public tuberculosis (TB clinics in urban Morocco. OBJECTIVE: Explore risk factors for TB treatment default and develop a prediction tool. Assess consequences of default, specifically risk for transmission or development of drug resistance. DESIGN: Case-control study comparing patients who defaulted from TB treatment and patients who completed it using quantitative methods and open-ended questions. Results were interpreted in light of health professionals' perspectives from a parallel study. A predictive model and simple tool to identify patients at high risk of default were developed. Sputum from cases with pulmonary TB was collected for smear and drug susceptibility testing. RESULTS: 91 cases and 186 controls enrolled. Independent risk factors for default included current smoking, retreatment, work interference with adherence, daily directly observed therapy, side effects, quick symptom resolution, and not knowing one's treatment duration. Age >50 years, never smoking, and having friends who knew one's diagnosis were protective. A simple scoring tool incorporating these factors was 82.4% sensitive and 87.6% specific for predicting default in this population. Clinicians and patients described additional contributors to default and suggested locally-relevant intervention targets. Among 89 cases with pulmonary TB, 71% had sputum that was smear positive for TB. Drug resistance was rare. CONCLUSION: The causes of default from TB treatment were explored through synthesis of qualitative and quantitative data from patients and health professionals. A scoring tool with high sensitivity and specificity to predict default was developed. Prospective evaluation of this tool coupled with targeted interventions based on our findings is warranted. Of note, the risk of TB transmission from patients who default treatment to others is likely to be high. The commonly-feared risk of drug resistance, though, may be low; a larger study is required to confirm

  19. Non-adherence to anti-tuberculosis treatment among internal migrants with pulmonary tuberculosis in Shenzhen, China: a cross-sectional study

    OpenAIRE

    Tang, Ying; Zhao, Meigui; Wang, Yunxia; Gong, Yanhong; Yin, Xiaoxv; Zhao, Angui; Zheng, Juanjuan; Liu, Zhenyang; Jian, Xiaofang; Wang, Wenxin; Wu, Chunmei; Lu, Zuxun

    2015-01-01

    Background Non-adherence to tuberculosis (TB) treatment threatens the success of treatment, increases the risk of TB spread, and leads to the development of drug resistance. The present study assessed non-adherence to anti-TB treatment among internal migrants with pulmonary TB living in Shenzhen, China, and examined risk factors for non-adherence in order to identify targets for intervention. Methods A total of 794 internal migrants with TB treated at Bao’an Hospital for Chronic Disease Preve...

  20. A comparative study on the adverse effects of two anti-tuberculosis drugs regimen in initial two-month treatment period

    OpenAIRE

    Begum Lutfun Nahar, A.K.M. Mosharrof Hossain, M. Monirul Islam and Dipti Rani Saha

    2006-01-01

    Tuberculosis (TB) is a leading cause of death throughout the world and Bangladesh stands 4th among high burden countries. Treatment of TB hampered with poor patient compliance and intolerance at least partly due to the adverse drug reactions.A prospective longitudinal non-randomized case study was conducted on 64 admitted patients in Chest Disease Hospital and Shahid Shamsuddin Hospital, Sylhet diagnosed as primary (Category I) and resistant or treatment failure (Category II) to compare adve...

  1. Eficacia y eficiencia del tratamiento antituberculoso en jurisdicciones sanitarias de Morelos Efficacy and efficiency of anti-tuberculosis treatment in 2 sanitary jurisdictions of Morelos, Mexico

    Directory of Open Access Journals (Sweden)

    Ma. de Lourdes García-García

    1998-09-01

    Full Text Available Objetivo. Evaluar la eficacia y la eficiencia del tratamiento antituberculoso administrado por la Secretaría de Salud (SSA en las jurisdicciones sanitarias de Cuernavaca y Cuautla, estado de Morelos, en el periodo 1992-1996. Material y métodos. Se hizo una revisión retrospectiva de las tarjetas de control de tratamiento en pacientes tuberculosos. Se utilizaron las definiciones contenidas en la Norma Oficial para el Control y Prevención de la Tuberculosis en la Atención Primaria a la Salud. La información fue vaciada en formatos estandarizados y se analizó mediante el programa SAS y Epi Info. Se visitaron las 149 unidades de atención primaria y los cuatro hospitales de la zona de estudio. Resultados. Se encontraron las tarjetas correspondientes a 288 pacientes, de los cuales 260 eran de casos nuevos. Estos pacientes recibieron en conjunto 311 tratamientos, de los cuales 85% fueron supervisados. Las tarjetas revisadas correspondieron al 60% de los casos notificados por la SSA en el mismo periodo. El grupo de pacientes tuberculosos tuvo mayor edad que la media poblacional y mayor probabilidad de pertenecer a los estratos socioeconómicos medio y bajo que la población general del área. Se analizaron 246 esquemas de tratamiento y se encontró que 32% presentó curación bacteriológica; 26%, curación probable; 18% abandonó el tratamiento; 1% fracasó en el tratamiento, y 3% murió durante el tratamiento. En 20% de los casos se desconoció el resultado del tratamiento. La frecuencia de curación fue mayor en los casos nuevos (61% que en los retratamientos (38% (pObjective. To evaluate the efficacy and efficiency of tuberculosis treatment administered by the Secretaría de Salud (SSA in the sanitary jurisdictions of Cuernavaca and Cuautla, Morelos, for the 1992-1996 period by retrospectively reviewing tuberculosis treatment control cards. Material and methods. Official Norm for Tuberculosis Prevention and Control in Primary Care Units

  2. TSH-CHECK-1 Test: Diagnostic Accuracy and Potential Application to Initiating Treatment for Hypothyroidism in Patients on Anti-Tuberculosis Drugs

    OpenAIRE

    Kosack, Cara S; Page, Anne-Laure; Van Hulsteijn, Leonie T.; Lentjes, Eef. G. W. M.

    2012-01-01

    Background Thyroid-stimulating hormone (TSH) promotes expression of thyroid hormones which are essential for metabolism, growth, and development. Second-line drugs to treat tuberculosis (TB) can cause hypothyroidism by suppressing thyroid hormone synthesis. Therefore, TSH levels are routinely measured in TB patients receiving second-line drugs, and thyroxin treatment is initiated where indicated. However, standard TSH tests are technically demanding for many low-resource settings where TB is ...

  3. Risk Factors for DOTS Treatment Default Among New HIV-TB Coinfected Patients in Nalgonda (Dist.) Telangana (State): A Case Control Study

    Science.gov (United States)

    Reddy Satti, Siva Balaji; Kondagunta, Nagaraj

    2016-01-01

    Background: The therapeutic regimens as recommended by the Revised National TB Control Programme (RNTCP) have been shown to be highly effective for both preventing and treating tuberculosis, but poor adherence to medication is a major barrier to its global control. Aim and Objectives: The study was conducted to assess the influence of patient related factors for DOTS Treatment Default among HIV-TB Co-infected cases. Setting and Design: This was a case control study conducted in Nalgond, Telangana. Materials and Methods: All new HIV-TB coinfected and DOTS-defaulted patients registered under RNTCP for the period from January 2010 to December 2012 were selected. Of the 154 patients, 23 had died and 11 could not be traced, and these were excluded. Thus the total number of available cases were 120 for those age- and sex-matched controls (HIV-TB coinfected patients and those who had completed the DOTS regimen successfully) were selected. Results: The mean age was 36.5 ± 9 years; the majority (23.3%) of patients defaulted during the second month of treatment. Significant risk factors associated with defaulting included unskilled occupation [adjusted odds ratio (AOR: 3.56; 95% confidence interval (CI): 1.1-11.56], lower middle class socioeconomic status (AOR: 17.16; 95% CI: 3.93-74.82), small family size (AOR: 21.3; 95% CI: 6.4-70.91), marital disharmony (AOR: 6.78; 95% CI: 1.93-23.76), not being satisfied with the conduct of health personnel (AOR: 7.38; 95% CI: 2.32-23.39), smoking (AOR: 8.5; 95% CI: 2.31-31.21), and side effects of drugs (AOR: 4.18; 95% CI: 1.35-12.9). Conclusion: Unskilled occupation, marital disharmony, small family size, lower middle class socioeconomic status, not being satisfied with the conduct of health personnel, smoking, and drug side effects were significantly associated with defaulting. Information on the pattern of tuberculosis (TB), the outcome of anti-tuberculosis treatment (ATT), and the factors associated with it will help in planning

  4. Evaluación del tratamiento antituberculoso en la zona norte del conurbano bonaerense Anti- tuberculosis treatment evaluation in Northern districts of Buenos Aires suburbs

    Directory of Open Access Journals (Sweden)

    Cristina Chirico

    2007-04-01

    Full Text Available El objetivo del presente estudio fue analizar el impacto epidemiológico producido por la aplicación de la estrategia del tratamiento para tuberculosis (TB de corta duración y directamente observado (DOTS, y su correlación con el éxito en la Región Sanitaria V, durante el año 2003. Se evaluó la curación comparando dos grupos de estudio. Grupo 1: municipios con 65% o más de los casos con DOTS, y Grupo 2: con 64% o menos de los pacientes bajo esta estrategia o sin su aplicación. Se analizó la letalidad global y de pacientes HIV (+ en ambos grupos. En el grupo 1 el éxito del tratamiento fue 85.7%, con curación en las formas pulmonares confirmadas de 86.2% y abandono de 8.8%. En el grupo 2 la curación alcanzó el 67.6%, en pulmonares confirmados 68.1% y el abandono de 21.8%. La letalidad global fue 5.2%, en pacientes HIV (+ 22.3% y en los HIV (- 4.1%. La curación en TB/HIV en el grupo 1 fue 55.2%, con abandono de 6.9%; en el grupo 2 curó el 46.4% y abandonó el 19.7%. El 31.0% de pacientes HIV (+ fallecieron en el grupo 1 y 16.1% en el grupo 2. La implementación del DOTS, permitió alcanzar la meta de curar el 85% de los casos, probando ser una herramienta eficaz, capaz de garantizar la curación de la mayoría de los pacientes y reducir el riesgo de enfermar de la comunidad.The aim of this study was to analyze the epidemiologic impact produced by Direct Observed Treatment Strategy (DOTS application regarding to its success in the 5th Sanitary Region during the year 2 003. The cure was evaluated by a cohort study comparing two groups. Group 1: Districts in which DOTS were applied in 65% or more TB patients; group 2: Districts applying DOTS in 64% or less, or without its implementation. The global mortality was analyzed on HIV (- as well as on HIV (+ patients in both groups. In Municipalities where DOTS strategy was applied in >65% of notified cases, the treatment success was 85.7%; the cure rate of bacteriological confirmed

  5. Hepatitis B or hepatitis C co-infection in individuals infected with human immunodeficiency virus and effect of anti-tuberculosis drugs on liver function

    OpenAIRE

    Padmapriyadarsini C; Chandrabose J; Victor L; Hanna L; Arunkumar N; Swaminathan Soumya

    2006-01-01

    Background: Tuberculosis (TB) and hepatitis are the two common co-infections in patients infected with human immunodeficiency virus (HIV). Anti-tuberculosis treatment (ATT) may have an effect on the liver enzymes in these co-infected HIV patients. Aims: To determine the prevalence of Hepatitis B and C virus coinfection in HIV infected patients in Tamilnadu and assess effects of anti-tuberculosis drugs on their liver function. Settings: HIV positive subjects referred to the Tuberculosis R...

  6. Nine- to Twelve-Month Anti-Tuberculosis Treatment Is Associated with a Lower Recurrence Rate than 6–9-Month Treatment in Human Immunodeficiency Virus-Infected Patients: A Retrospective Population-Based Cohort Study in Taiwan

    OpenAIRE

    Jann-Yuan Wang; Hsin-Yun Sun; Jann-Tay Wang; Chien-Ching Hung; Ming-Chih Yu; Chih-Hsin Lee; Li-Na Lee

    2015-01-01

    Background Human immunodeficiency virus (HIV)-infected patients are at an increased risk of tuberculosis (TB) and its recurrence following completion of anti-TB treatment. We investigated whether extending anti-TB treatment to 9 months or longer reduces TB recurrence. Methods HIV-infected patients who were diagnosed with pulmonary TB between 1997 and 2009 and who received anti-TB treatment for a duration between 5.5 and 12.5 months were identified from the National Health Insurance Research D...

  7. The search for new sterilizing anti-tuberculosis drugs.

    Science.gov (United States)

    Mitchison, Denis A

    2004-05-01

    To be of use in the control of tuberculosis, any new drug must be capable of shortening the duration of treatment by accelerating sterilizing activity, that is the rate at which Mycobacterium tuberculosis is killed in the lesions. The most difficult to kill are the extra-cellular bacilli in cavities. Persistence during therapy arises because there is a proportion of slowly metabolising bacilli (persisters) in the cavitary bacterial population at the start of treatment. Bacterial growth is slowed by low oxygen tension, quorum sensing and old age, but probably not by cellular immunity, since there are few professional phagocytic cells in cavities. The degree of phenotypic resistance to the bactericidal action of drugs can go through several stages: (i) the non-replicating stages 1 and 2 of micro-aerophilic adaptation, described by Wayne; (ii) a "tolerant" population that survives exposure to high rifampicin concentrations and is capable of growth in liquid medium but not on solid medium; and (iii) a population found in the sterile state of Cornell model mice which cannot grow initially in either liquid or solid medium but will eventually cause re-activation of tuberculosis. In all of these stages the bacilli are phenotypically resistant; there is no selection for genomic drug resistance. Rifampicin and pyrazinamide are the two drugs largely responsible for sterilizing activity during current treatment. Pyrazinamide is unique amongst anti-tuberculosis drugs in having no genomic site of action and having greater bactericidal activity as bacillary metabolism slows down; it is remarkably effective in human disease. The development of a new drug with a similar mode of activity might be very fruitful, especially if there were no need for an acid environment. Current methods advocated for drug development pass through a number of complex stages: choice of a genomic target, development of an in vitro assay, high throughput screening and identification of lead compounds

  8. Risk Factors Associated with Default from Multi- and Extensively Drug-Resistant Tuberculosis Treatment, Uzbekistan: A Retrospective Cohort Analysis

    Science.gov (United States)

    Lalor, Maeve K.; Greig, Jane; Allamuratova, Sholpan; Althomsons, Sandy; Tigay, Zinaida; Khaemraev, Atadjan; Braker, Kai; Telnov, Oleksander; du Cros, Philipp

    2013-01-01

    Background The Médecins Sans Frontières project of Uzbekistan has provided multidrug-resistant tuberculosis treatment in the Karakalpakstan region since 2003. Rates of default from treatment have been high, despite psychosocial support, increasing particularly since programme scale-up in 2007. We aimed to determine factors associated with default in multi- and extensively drug-resistant tuberculosis patients who started treatment between 2003 and 2008 and thus had finished approximately 2 years of treatment by the end of 2010. Methods A retrospective cohort analysis of multi- and extensively drug-resistant tuberculosis patients enrolled in treatment between 2003 and 2008 compared baseline demographic characteristics and possible risk factors for default. Default was defined as missing ≥60 consecutive days of treatment (all drugs). Data were routinely collected during treatment and entered in a database. Potential risk factors for default were assessed in univariate analysis using chi-square test and in multivariate analysis with logistic regression. Results 20% (142/710) of patients defaulted after a median of 6 months treatment (IQR 2.6–9.9). Factors associated with default included severity of resistance patterns (pre-extensively drug-resistant/extensively drug-resistant tuberculosis adjusted odds ratio 0.52, 95%CI: 0.31–0.86), previous default (2.38, 1.09–5.24) and age >45 years (1.77, 1.10–2.87). The default rate was 14% (42/294) for patients enrolled 2003–2006 and 24% (100/416) for 2007–2008 enrolments (p = 0.001). Conclusions Default from treatment was high and increased with programme scale-up. It is essential to ensure scale-up of treatment is accompanied with scale-up of staff and patient support. A successful first course of tuberculosis treatment is important; patients who had previously defaulted were at increased risk of default and death. The protective effect of severe resistance profiles suggests that understanding disease

  9. Sale of anti-tuberculosis drugs through private pharmacies: a cross sectional study in Kerala, India.

    Directory of Open Access Journals (Sweden)

    Binoo Divakaran

    2011-03-01

    Full Text Available

    Background: Private health care providers are largely the first point of contact for Tuberculosis (TB patients, who either undergo treatment from private practitioners or buy medicines on their own from private pharmacies. Aims: This study assessed the availability, sale and magnitude of anti-tuberculosis drugs dispensing through private pharmacies.

    Methodology: The present cross sectional study was conducted among private pharmacies located along the national highway from Thalassery to Payyannur in the Kannur district of Kerala, India. A total of 38 private pharmacies located along the national highway were included.

    Results: The duration that anti–TB drugs had been on sale showed that 74.3% of pharmacies had started to sell these drugs only less than ten years ago. The majority (82.9% of the private pharmacies received up to 5 prescriptions for anti-TB drugs weekly. Out of the total of 35 pharmacies selling these drugs, 22 (62.9% reported an increase in their sales. Nearly 82% of those pharmacies that reported an increase in the sale of anti-TB drugs were selling these drugs for less than the past ten years.

    Conclusions: The current study shows that a large number of tuberculosis patients are still approaching private pharmacies for anti-tuberculosis drugs. This tendency has to be completely stopped and needs properly planned strategies to encourage private pharmacies to participate actively in the DOTS (Direct Observation Treatment Short course program of the Government, by providing them attractive alternative incentives

  10. Determinants of Default from Tuberculosis Treatment among Patients with Drug-Susceptible Tuberculosis in Karachi, Pakistan: A Mixed Methods Study.

    Directory of Open Access Journals (Sweden)

    Natasha Chida

    Full Text Available Non-adherence to tuberculosis therapy can lead to drug resistance, prolonged infectiousness, and death; therefore, understanding what causes treatment default is important. Pakistan has one of the highest burdens of tuberculosis in the world, yet there have been no qualitative studies in Pakistan that have specifically examined why default occurs. We conducted a mixed methods study at a tuberculosis clinic in Karachi to understand why patients with drug-susceptible tuberculosis default from treatment, and to identify factors associated with default. Patients attending this clinic pick up medications weekly and undergo family-supported directly observed therapy.In-depth interviews were administered to 21 patients who had defaulted. We also compared patients who defaulted with those who were cured, had completed, or had failed treatment in 2013.Qualitative analyses showed the most common reasons for default were the financial burden of treatment, and medication side effects and beliefs. The influence of finances on other causes of default was also prominent, as was concern about the effect of treatment on family members. In quantitative analysis, of 2120 patients, 301 (14.2% defaulted. Univariate analysis found that male gender (OR: 1.34, 95% CI: 1.04-1.71, being 35-59 years of age (OR: 1.54, 95% CI: 1.14-2.08, or being 60 years of age or older (OR: 1.84, 95% CI: 1.17-2.88 were associated with default. After adjusting for gender, disease site, and patient category, being 35-59 years of age (aOR: 1.49, 95% CI: 1.10-2.03 or 60 years of age or older (aOR: 1.76, 95% CI: 1.12-2.77 were associated with default.In multivariate analysis age was the only variable associated with default. This lack of identifiable risk factors and our qualitative findings imply that default is complex and often due to extrinsic and medication-related factors. More tolerable medications, improved side effect management, and innovative cost-reduction measures are needed to

  11. Reasons for default from treatment of chronic illnesses in a primary healthcare program in rural Tamil Nadu

    OpenAIRE

    Henry R Jennens; Rajkumar Ramasamy; Brigitte Tenni

    2013-01-01

    Chronic illnesses are an increasing cause of morbidity and mortality in rural India. Many patients default from treatment, and exploring their reasons for the same may suggest strategies to improve service accessibility and acceptability. A qualitative study was conducted of 22 patient interviews, six key informant interviews, and two patient focus group discussions for investigating the reasons for default at the KC Patty Primary Health Centre and surrounding villages in Kodaikanal Taluk, Di...

  12. Risk factors for development of paradoxical response during anti-tuberculosis treatment in patients with pulmonary tuberculosis%肺结核抗痨中发生类赫反应的危险因素

    Institute of Scientific and Technical Information of China (English)

    胡良安; 傅玉; 罗永艾; 黄习臣

    2014-01-01

    目的:研究肺结核抗痨过程中发生类赫反应( PR)的频率、临床特点及其危险因素。方法采用病历资料的回顾性列队研究。结果符合条件的1310例肺结核患者抗痨后76例发生PR(5.8%),发生PR的时间是抗痨后(40±28)d。发热和咳嗽是PR的最常见症状。76例PR患者中误诊为耐药结核24例,肺炎32例和肺癌6例。发生PR的危险因素是:体重指数低、低白蛋白血症、初始血淋巴细胞数低和发生PR时淋巴细胞数较大增加( P均<0.05)。结论在肺结核患者抗痨中出现PR是常见现象,且易误诊;低蛋白血症、低体重指数、初始淋巴细胞数量较低以及初始与抗痨后淋巴细胞数的变化量较大的肺结核患者更易发生PR,这有助于区别是PR发生,或是肺炎或耐药而导致抗痨治疗失败。%Objective To evaluate the incidence , clinical characteristics and predicting factors for the development of paradoxical response ( PR) in patients with pulmonary tuberculosis ( TB) .Methods A retrospective cohort study was executed including 1 310 patients who were diagnosed and treated with pulmonary TB .Results PR was present in 76(5.8%) of 1 310 patients after 40±28 days following ini-tiation of treatment.Fever and cough were the most common symptoms associated with PR .24(31.6%) patients had been initially misdiag-nosed of drug-resistant TB,32(42.1%) patients had been misdiagnosed of pneumonia and 6(7.9%) patients had been misdiagnosed of lung cancer.The risk factors for PR were low body mass index (BMI), low serum albumin level, low baseline lymphocyte counts and lymphocyte count greater increase during PR development (all P<0.05).Conclusions PR is not an uncommon problem in pulmonany TB and is com-mon misdiagnosed.Low BMI, baseline hypoalbuminaemia, lymphopaenia and a greater change in lymphocyte count during PR development are associated with the development of PR .This is useful for clinical

  13. Hepatitis B or hepatitis C co-infection in individuals infected with human immunodeficiency virus and effect of anti-tuberculosis drugs on liver function

    Directory of Open Access Journals (Sweden)

    Padmapriyadarsini C

    2006-01-01

    Full Text Available Background: Tuberculosis (TB and hepatitis are the two common co-infections in patients infected with human immunodeficiency virus (HIV. Anti-tuberculosis treatment (ATT may have an effect on the liver enzymes in these co-infected HIV patients. Aims: To determine the prevalence of Hepatitis B and C virus coinfection in HIV infected patients in Tamilnadu and assess effects of anti-tuberculosis drugs on their liver function. Settings: HIV positive subjects referred to the Tuberculosis Research Centre, Chennai Materials and Methods: All HIV infected patients referred to the Tuberculosis Research centre, from March 2000 to May 2004, were screened for Hepatitis B surface antigen (HBsAg & Hepatitis C virus (HCV antibodies by enzyme linked immunoabsorbent assay (ELISA. HIV infection was confirmed using two rapid tests and one ELISA. Patients were given either short- course anti-tuberculosis treatment or preventive therapy for tuberculosis, depending on the presence or absence of active TB, if their baseline liver functions were within normal limits. None of these patients were on antiretroviral therapy during the study period. Statistical Analysis: Paired t-test was used to find the significance between baseline and end of treatment liver enzymes levels, while logistic regression was done for assessing various associations. Results: Of the 951 HIV-infected patients, 61 patients (6.4% were HBsAg positive, 20 (2.1% had demonstrable anti HCV antibodies in their blood. Serial estimation of liver enzymes in 140 HIV patients (81 being co-infected with either HBV or HCV showed that 95% did not develop any liver toxicity while they were on anti-tuberculosis treatment or prophylaxis. Conclusions: The prevalence of hepatitis B and C coinfection was fairly high in this largely heterosexually infected population supporting the use of more careful screening for these viruses in HIV positive persons in this region. Anti-tuberculosis therapy as well as TB preventive

  14. Factors associated with tuberculosis treatment default in an endemic area of the Brazilian Amazon: a case control-study.

    Directory of Open Access Journals (Sweden)

    Marlucia da Silva Garrido

    Full Text Available SETTING: Treatment default is a serious problem in tuberculosis control because it implies persistence of infection source, increased mortality, increased relapse rates and facilitates the development of resistant strains. OBJECTIVE: This study analyzed tuberculosis treatment default determinants in the Amazonas State to contribute in planning appropriate control interventions. DESIGN: Observational study with a retrospective cohort using Brazilian Disease Notification System data from 2005 to 2010. A nested case control study design was used. Patients defaulting from treatment were considered as 'cases' and those completing treatment as 'controls'. In the analysis, 11,312 tuberculosis patients were included, 1,584 cases and 9,728 controls. RESULTS: Treatment default was observed to be associated to previous default (aOR 3.20; p<0.001, HIV positivity (aOR 1.62; p<0.001, alcoholism (aOR 1.51; p<0.001, low education level (aOR 1.35; p<0.001 and other co-morbidities (aOR 1.31; p = 0.05. Older patients (aOR 0.98; p = 0.001 and DOT (aOR 0,72; p<0.01 were considered as protective factor for default. CONCLUSIONS: Associated factors should be considered in addressing care and policy actions to tuberculosis control. Information on disease and treatment should be intensified and appropriate to the level of education of the population, in order to promote adherence to treatment and counter the spread of multidrug resistance to anti-TB drugs.

  15. Default probabilities and default correlations

    OpenAIRE

    Erlenmaier, Ulrich; Gersbach, Hans

    2001-01-01

    Starting from the Merton framework for firm defaults, we provide the analytics and robustness of the relationship between default correlations. We show that loans with higher default probabilities will not only have higher variances but also higher correlations between loans. As a consequence, portfolio standard deviation can increase substantially when loan default probabilities rise. This result has two important implications. First, relative prices of loans with different default probabili...

  16. Defaults and Donations

    DEFF Research Database (Denmark)

    Altmann, Steffen; Falk, Armin; Heidhues, Paul;

    We study how website defaults affect consumer behavior in the domain of charitable giving. In a field experiment that was conducted on a large platform for making charitable donations over the web, we exogenously vary the default options in two distinct choice dimensions. The first pertains...... to the primary donation decision, namely, how much to contribute to the charitable cause. The second relates to an "add-on" decision of how much to contribute to supporting the online platform itself. We find a strong impact of defaults on individual behavior: in each of our treatments, the modal positive...... contributions in both choice dimensions invariably correspond to the specified default amounts. Defaults, nevertheless, have no impact on aggregate donations. This is because defaults in the donation domain induce some people to donate more and others to donate less than they otherwise would have. In contrast...

  17. Reasons for default from treatment of chronic illnesses in a primary healthcare program in rural Tamil Nadu

    Directory of Open Access Journals (Sweden)

    Henry R Jennens

    2013-01-01

    Full Text Available Chronic illnesses are an increasing cause of morbidity and mortality in rural India. Many patients default from treatment, and exploring their reasons for the same may suggest strategies to improve service accessibility and acceptability. A qualitative study was conducted of 22 patient interviews, six key informant interviews, and two patient focus group discussions for investigating the reasons for default at the KC Patty Primary Health Centre and surrounding villages in Kodaikanal Taluk, Dindigul district, Tamil Nadu. The reasons included money or transport difficulties, frequent travel, feeling healthy, focus on work, fear of scolding from clinic staff, medication side effects, preference for alternative therapy, and depression. Some reasons were only divulged after an extended discussion. Support from families and village-level health workers (VLHWs were also identified as important. Recommendations include more open and patient communication between health workers and defaulting patients, in addition to recruitment of more VLHWs.

  18. Patient characteristics associated with tuberculosis treatment default: a cohort study in a high-incidence area of Lima, Peru

    OpenAIRE

    Lackey, Brian; Seas, Carlos; Van der Stuyft, Patrick; Otero, Larissa

    2015-01-01

    Background Although tuberculosis (TB) is usually curable with antibiotics, poor adherence to medication can lead to increased transmission, drug resistance, and death. Prior research has shown several factors to be associated with poor adherence, but this problem remains a substantial barrier to global TB control. We studied patients in a high-incidence district of Lima, Peru to identify factors associated with premature termination of treatment (treatment default). Methods We conducted a pro...

  19. Charitable Giving, Emotions, and the Default Effect

    NARCIS (Netherlands)

    Noussair, Charles; Habetinova, Lenka

    2015-01-01

    We report an experiment to study the effect of defaults on charitable giving. In three different treatments, participants face varying default levels of donation. In three other treatments that are paired with the first three, they receive the same defaults, but are informed that defaults are though

  20. Anti-Tuberculosis Drug Induced Hepatotoxicity among TB/HIV Co-Infected Patients at Jimma University Hospital, Ethiopia: Nested Case-Control Study

    OpenAIRE

    Alima Hassen Ali; Tefera Belachew; Alemeshet Yami; Wubeante Yenet Ayen

    2013-01-01

    BACKGROUND: This study was carried out to determine the incidence and predictors of anti-tuberculosis drug induced hepatotoxicity among TB/HIV co-infected patients at Jimma University Hospital, Ethiopia. METHODS/PRINCIPAL FINDINGS: A nested case-control study was conducted by reviewing charts of all TB/HIV co-infected patients who commenced anti-TB treatment from January 2008 to December 2011 at Jimma University Hospital. Patients who had developed hepatotoxicity after at least 5 days of stan...

  1. Factors Associated with Anti-Tuberculosis Medication Adverse Effects: A Case-Control Study in Lima, Peru

    OpenAIRE

    Kocfa Chung-Delgado; Alejandro Revilla-Montag; Sonia Guillen-Bravo; Eduardo VelezSegovia; Andrea Soria-Montoya; Alexandra Nun˜ ez-Garbin; Wilmer Silva-Caso; Antonio Bernabe-Ortiz

    2011-01-01

    Background: Long-term exposure to anti-tuberculosis medication increases risk of adverse drug reactions and toxicity. The objective of this investigation was to determine factors associated with anti-tuberculosis adverse drug reactions in Lima, Peru, with special emphasis on MDR-TB medication, HIV infection, diabetes, age and tobacco use. Methodology and Results: A case-control study was performed using information from Peruvian TB Programme. A case was defined as having reported an anti-TB a...

  2. THE QUESTIONS OF ALLERGY AND ANTI-TUBERCULOSIS IMMUNITY IN THE WORKS OF М.М. TSEHNOVITSER

    OpenAIRE

    Kuchma Y.U; Moiseenko T.M

    2014-01-01

    The mechanism of anti-tuberculosis immunity drew the attention of scientists since the established of the infectious nature of tuberculosis. The famous ukrainian microbiologist and immunologist M.M. Tsehnovitser in period from 1921 to 1940 years spent a lot of original experiments for elucidation of the role of allergy in the anti-tuberculosis immunity. M.M. Tsehnovitser believed that a common cause of infectious allergy is tuberculosis granuloma, which even at rest eliminated weakened microb...

  3. Drug-induced Hepatotoxicity of Anti-tuberculosis Drugs and Their Serum Levels

    OpenAIRE

    Jeong, Ina; Park, Jong-Sun; Cho, Young-Jae; Yoon, Ho Il; Song, Junghan; Lee, Choon-Taek; Lee, Jae-Ho

    2015-01-01

    The correlation between serum anti-tuberculosis (TB) drug levels and the drug-induced hepatotoxicity (DIH) remains unclear. The purpose of this study was to investigate whether anti-TB DIH is associated with basal serum drug levels. Serum peak levels of isoniazid (INH), rifampicin (RMP), pyrazinamide (PZA), and ethambutol (EMB) were analyzed in blood samples 2 hr after the administration of anti-TB medication. Anti-TB DIH and mild liver function test abnormality were diagnosed on the basis of...

  4. Anti-tuberculosis drug resistance in Sub-Saharan Africa: The case of Uganda

    OpenAIRE

    Cobelens, F.G.J.; Joloba, M.L.; Lukoye, D

    2015-01-01

    This thesis reports findings of six studies including two tuberculosis (TB) drug resistance surveys, a comparative study of HIV infection rates among patients enrolled in the survey and those under routine TB/HIV surveillance, two TB molecular epidemiological analyses and a systematic review and meta-analysis of drug-resistant TB in sub-Saharan Africa. It provides a general introduction to anti-tuberculosis drug resistance in the world and associated risk factors. Results from the drug resist...

  5. Chemical constituents and anti-tuberculosis activity of ink extracts of cuttlefish, Sepiella inermis

    Directory of Open Access Journals (Sweden)

    Muthusamy Ravichandiran

    2013-11-01

    Full Text Available Objective: To study the chemical constituents and the anti-tuberculosis activity of methanol and chloroform ink extracts of Sepiella inermis. Methods: Pulverized ink powder was extracted separately with chloroform and methanol. Chemical analysis was carried out by UV-VIS spectrophotometer, FT-IR and GC-MS. Crude extracts were tested in vitro for their activity against Mycobacterium tuberculosis using Lowenstein Jensen (L-J medium. Activity in L-J medium was assessed by mean reduction in number of colonies on extract containing bottles as compared to extract free controls. Results: GC-MS of methanol extract revealed four compounds viz. hexadecanoic acid, 9, 12- octadecadienoic acid, 9-octadecenoic acid and octadecanoic acid. The chloroform extract containing fourteen compounds. The methanol extract exhibited anti-tuberculosis activity in L-J medium at 64 µg/mL with the observed inhibition of 14 CFU. Chloroform extract displayed a weak activity against Mycobacterium tuberculosis. Conclusions: This investigation showed the methanol extract exhibited significant activity against Mycobacterium tuberculosis than chloroform extract. Since ink of sepia is available abundantly as a waste material, further studies aimed at isolation and efficacy of active substances pave the way for new anti-tuberculosis drugs.

  6. Adequacy of anti-tuberculosis drug prescriptions in Viet Nam

    DEFF Research Database (Denmark)

    Hoa, N B; Lauritsen, J M; Rieder, H L

    2012-01-01

    SETTING: National Tuberculosis Program, Viet Nam, 2008. OBJECTIVES: To determine drug prescription adherence to national guidelines, to examine factors associated with an erroneous dosage of rifampin (RMP) and to evaluate the impact of an insufficient RMP dosage on treatment outcome. METHODS: A...... representative sample of 30 treatment units was randomly selected. All patient treatment cards enrolled in these units were obtained, and data were double-entered and validated before calculating the adequacy of the individual drug prescriptions. RESULTS: Of 3412 tuberculosis treatment cards, 3225 (94.5%) had...

  7. New anti-tuberculosis drugs and regimens: 2015 update

    OpenAIRE

    Lia D'Ambrosio; Rosella Centis; Giovanni Sotgiu; Emanuele Pontali; Antonio Spanevello; Giovanni Battista Migliori

    2015-01-01

    Over 480 000 cases of multidrug-resistant (MDR) tuberculosis (TB) occur every year globally, 9% of them being affected by extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. The treatment of MDR/XDR-TB is unfortunately long, toxic and expensive, and the success rate largely unsatisfactory (

  8. A new method for identifying causal genes of schizophrenia and anti-tuberculosis drug-induced hepatotoxicity.

    Science.gov (United States)

    Huang, Tao; Liu, Cheng-Lin; Li, Lin-Lin; Cai, Mei-Hong; Chen, Wen-Zhong; Xu, Yi-Feng; O'Reilly, Paul F; Cai, Lei; He, Lin

    2016-01-01

    Schizophrenia (SCZ) may cause tuberculosis, the treatments for which can induce anti-tuberculosis drug-induced hepatotoxicity (ATDH) and SCZ-like disorders. To date, the causal genes of both SCZ and ATDH are unknown. To identify them, we proposed a new network-based method by integrating network random walk with restart algorithm, gene set enrichment analysis, and hypergeometric test; using this method, we identified 500 common causal genes. For gene validation, we created a regularly updated online database ATDH-SCZgenes and conducted a systematic meta-analysis of the association of each gene with either disease. Till now, only GSTM1 and GSTT1 have been well studied with respect to both diseases; and a total of 23 high-quality association studies were collected for the current meta-analysis validation. Finally, the GSTM1 present genotype was confirmed to be significantly associated with both ATDH [Odds Ratio (OR): 0.71, 95% confidence interval (CI): 0.56-0.90, P = 0.005] and SCZ (OR: 0.78, 95% CI: 0.66-0.92, P = 0.004) according to the random-effect model. Furthermore, these significant results were supported by "moderate" evidence according to the Venice criteria. Our findings indicate that GSTM1 may be a causal gene of both ATDH and SCZ, although further validation pertaining to other genes, such as CYP2E1 or DRD2, is necessary. PMID:27580934

  9. New anti-tuberculosis drugs and regimens: 2015 update

    Directory of Open Access Journals (Sweden)

    Lia D'Ambrosio

    2015-05-01

    Full Text Available Over 480 000 cases of multidrug-resistant (MDR tuberculosis (TB occur every year globally, 9% of them being affected by extensively drug-resistant (XDR strains of Mycobacterium tuberculosis. The treatment of MDR/XDR-TB is unfortunately long, toxic and expensive, and the success rate largely unsatisfactory (<20% among cases with resistance patterns beyond XDR. The aim of this review is to summarise the available evidence-based updated international recommendations to manage MDR/XDR-TB, and to update the reader on the role of newly developed drugs (delamanid, bedaquiline and pretomanid as well as repurposed drugs (linezolid and meropenem clavulanate, among others used to treat these conditions within new regimens. A nonsystematic review based on historical trials results as well as on recent literature and World Health Organization (WHO guidelines has been performed, with special focus on the approach to managing MDR/XDR-TB. The new, innovative global public health interventions, recently approved by WHO and known as the “End TB Strategy”, support the vision of a TB-free world with zero death, disease and suffering due to TB. Adequate, universally accessed treatment is a pre-requisite to reach TB elimination. New shorter, cheap, safe and effective anti-TB regimens are necessary to boost TB elimination.

  10. Antimicrobial peptides as novel anti-tuberculosis therapeutics.

    Science.gov (United States)

    Silva, João P; Appelberg, Rui; Gama, Francisco Miguel

    2016-01-01

    Tuberculosis (TB), a disease caused by the human pathogen Mycobacterium tuberculosis, has recently joined HIV/AIDS as the world's deadliest infectious disease, affecting around 9.6 million people worldwide in 2014. Of those, about 1.2 million died from the disease. Resistance acquisition to existing antibiotics, with the subsequent emergence of Multi-Drug Resistant mycobacteria strains, together with an increasing economic burden, has urged the development of new anti-TB drugs. In this scope, antimicrobial peptides (AMPs), which are small, cationic and amphipathic peptides that make part of the innate immune system, now arise as promising candidates for TB treatment. In this review, we analyze the potential of AMPs for this application. We address the mechanisms of action, advantages and disadvantages over conventional antibiotics and how problems associated with its use may be overcome to boost their therapeutic potential. Additionally, we address the challenges of translational development from benchside to bedside, evaluate the current development pipeline and analyze the expected global impact from a socio-economic standpoint. The quest for more efficient and more compliant anti-TB drugs, associated with the great therapeutic potential of emerging AMPs and the rising peptide market, provide an optimal environment for the emergence of AMPs as promising therapies. Still, their pharmacological properties need to be enhanced and manufacturing-associated issues need to be addressed. PMID:27235189

  11. Fresh Air and Good Food: Children and the Anti-Tuberculosis Campaign in the Netherlands c.1900-1940

    Science.gov (United States)

    Bakker, Nelleke

    2010-01-01

    As elsewhere in the Western world, between 1900 and 1940 the anti-tuberculosis campaign in the Netherlands produced a wide range of initiatives to promote child health. In each of these the social and the medical were linked, as the hygienic "mood" was encouraged by a child-saving ethos that focused upon the poor. In this article the author…

  12. Social Defaults: Observed Choices Become Choice Defaults

    OpenAIRE

    Young Eun Huh; Joachim Vosgerau; Morewedge, Carey K.

    2014-01-01

    Defaults effects can be created by social contexts. The observed choices of others can become social defaults, increasing their choice share. Social default effects are a novel form of social influence not due to normative or informational influence: participants were more likely to mimic observed choices when choosing in private than in public (experiment 1) and when stakes were low rather than high (experiment 2). Like other default effects, social default effects were greater for uncertain...

  13. A case study on tuberculosis treatment defaulters in Delhi: Weak health links of the community with the public sector, unsupported migrants and some misconceptions

    Directory of Open Access Journals (Sweden)

    Vinitha Jayachandran

    2014-01-01

    Full Text Available Background: Defaulters are producing the challenging, daunting category of drug resistant cases. It is important to examine and understand the patient′s notions and terms to manage them effectively. Objective: To study the reasons behind failure of adherence to treatment and to assess the health care seeking behaviour with awareness of these patients regarding the public sector provisions. Materials and Methods: In depth interviews with ten patients who had defaulted and were undergoing CAT-II treatment which included both retreatment defaulters and new defaulters, were conducted by repeated contacts in Fatehpur Beri PHC DOTS centre. Results: People refuse to seek treatment from a government health centre when they fall sick seriously as they are ready to get treated at any expense and seek private health care facility for the prompt treatment. There is a notion that free service from public sector is not as effective as private corporate hospitals. In the public sector patients defaulted because of side effects of drugs, fear of getting admitted in big tuberculosis (TB hospitals, incompatible timing, neglect, long waiting time, TB deaths in the family and lack of family support. Among migrants, lack of employers support, family support forced them to return home. Ignorance about existence of DOTS centre with free treatment was observed. Most of the patients were unaware that incomplete treatment could lead to disease. Misconceptions observed were that treatment was futile (talk in the community about drugs being useless and most of the patients were afraid of the disease and thought they could die because of it. Conclusion: Proposed measures include: Recognition of traditional medicine/complementary alternative medicine practitioners for universal access to TB diagnosis and care, Public sector should be made attractive to the middle class society through enhancement of services and user fees and empowerment initiatives for lack of social

  14. Comparative cytotoxic and anti-tuberculosis activity of Aplysina caissara marine sponge crude extracts.

    Science.gov (United States)

    Azevedo, Luciana G; Muccillo-Baisch, Ana L; Filgueira, Daza de M V B; Boyle, Robert T; Ramos, Daniela F; Soares, Andrea D; Lerner, Clea; Silva, Pedro A; Trindade, Gilma S

    2008-01-01

    Three crude extracts of Aplysina caissara, a marine sponge endemic to Brazil, were tested against a hepatoma cell line and Mycobacterium tuberculosis. The results demonstrate that all extracts are toxic and capable of inhibiting cellular growth. Additionally, the extracts produced morphological aberrations and inhibited cell attachment to culture substrates. These effects were dose/time dependent. Our results also suggest that reactive oxygen species (ROS) production is not involved in the cytotoxic processes levied by the extracts employed in this study and that active metabolites are likely to be present in the polar fractions of the crude extracts. Finally, our results indicate that all three extracts exhibit a moderate anti-tuberculosis capacity, and that the removal of an extract's lipid fraction appears to diminish this activity. PMID:17826358

  15. Monitoring the ingestion of anti-tuberculosis drugs by simple non-invasive methods.

    Science.gov (United States)

    Sirgel, F A; Maritz, J S; Venter, A; Langdon, G; Smith, P J; Donald, P R

    2006-01-13

    This investigation retrospectively assessed inexpensive non-invasive qualitative methods to monitor the ingestion of anti-tuberculosis drugs isoniazid, rifampicin and rifapentine. Results showed that commercial test strips detected the isoniazid metabolites isonicotinic acid and isonicotinylglycine as efficiently as the isonicotinic acid method in 150 urine samples. The presence of rifamycins in urine samples (n=1085) was detected by microbiological assay techniques and the sensitivity compared to the n-butanol extraction colour test in 91 of these specimens. The proportions detected by the two methods were significantly different and the sensitivity of the n-butanol procedure was only 63.8% (95% CL 51.2-76.4%) as compared to that of the superior microbiological method. Final validation (n=691) showed that qualitative assays measure isoniazid and rifamycin ingestion with an efficiency similar to high-performance liquid chromatography. The qualitative procedures may therefore be valuable in clinical trials and in tuberculosis clinics to confirm drug ingestion. PMID:16303269

  16. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc

    2015-05-27

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data complexity has restricted their clinical application. A library (1,325 mutations) predictive of DR for 15 anti-tuberculosis drugs was compiled and validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online ‘TB-Profiler’ tool was developed to report DR and strain-type profiles directly from raw sequences. Using our DR mutation library, in silico diagnostic accuracy was superior to some commercial diagnostics and alternative databases. The library will facilitate sequence-based drug-susceptibility testing.

  17. Tuberculosis treatment among smear positive tuberculosis patients

    International Nuclear Information System (INIS)

    Tuberculosis is a major health problem in many parts of the world. Delay in initiation of the treatment may result in prolonged infectious state, drug resistance, relapse and death. Objectives: To determine the factors responsible for not starting tuberculosis treatment among smear positive tuberculosis patients. Study type, settings and duration: This cross sectional study was done at Pakistan Medical Research Council TB Research Center, King Edward Medical University, Lahore, from fifth March 2010 to fifth December 2010. Patients and Methods: Fifty sputum smear positive patients of tuberculosis who did not register themselves in treatment register and presumably did not initiate anti tuberculosis treatment were contacted using telephone or traced by their home addresses. Once contact was established, they were inquired about the reasons for not starting tuberculosis treatment. Results: Of 50 patients 38(76%)belonged to the lower socio economic class and 12(24%) to the lower middle class. Fourteen patients (28%) were illiterate and 23(46%) had only 8 years of education. Of the 50 cases 41(82%) were taking treatment from traditional healers and 4% did not go back to the DOTS program. Physical condition of the patient, social, domestic and religious issues also played some role in default. Conclusions: Lack of health education and poverty were the main factors responsible for non compliance from treatment. Policy message: Sputum testing sites should have a paramedic who should educate the patients about the benefits of treatment and the dangers of default or partial treatment. (author)

  18. Value of serum procalcitonin in anti-tuberculosis therapeutic effect evaluation for tuberculosis%血清降钙素原在肺结核抗结核治疗疗效评估中的价值

    Institute of Scientific and Technical Information of China (English)

    徐立; 金雪

    2013-01-01

    目的研究血清降钙素原在肺结核抗结核治疗疗效评估中的价值。方法选择2012年1月~2013年1月本科诊治的肺结核患者为研究对象(观察组),以同期未行抗结核治疗的肺结核患者为对照(对照组),比较两组患者治疗前后血清降钙素原的水平并分析不同水平降钙素原抗结核治疗疗效差异。结果观察组和对照组肺结核患者治疗前血清降钙素原差异无统计学意义,观察组患者治疗后1个月、3个月和6个月血清降钙素原显著降低( P<0.05),对照组治疗1个月、3个月和6个月血清降钙素原升高,观察组肺结核患者治疗1个月、3个月和6个月血清降钙素原均显著低于对照组(P<0.05)。治疗前降钙素原水平显著升高、轻度升高和正常患者治愈率依次降低(P<0.05)。结论肺结核患者血清降钙素原可作为其抗结核治疗疗效评估的标志物。%Objective To study the value of serum procalcitonin in anti-tuberculosis therapeutic effect evaluation for tuberculosis. Methods The patients with tuberculosis treated with anti-tuberculosis therapy in our department from January 2012 to January 2013 were selected as the observation group, while no anti-tuberculosis treatment patients with tuberculosis during the same period were selected as the control group. The level of serum procalcitonin in the two groups before and after the treatment were compared and the anti-tuberculosis therapeutic effect difference of different levels of procalcitonin were analyzed. Results There was not significant difference in the level of serum procalcitonin before the treatment between the observation group and the control group. The levels of serum procalcitonin in the observation group after the treatment of 1 month, 3 months and 6 months decreased significantly(P<0.05), while the levels of serum procalcitonin in the control group after the treatment of 1 month, 3 months and 6 months

  19. Defaulting from anti-tuberculosis treatment in a teaching hospital in Rio de Janeiro,Brazil%巴西里约热内卢一所教学医院的抗结核治疗不合作情况调查

    Institute of Scientific and Technical Information of China (English)

    C.L.G.Salles; M.B.Conde; C.Hofer; A.J.L.A.Cunha; A. L. Calcada; D.F.Menezes; L.Sa; A.L.Kritski

    2004-01-01

    背景:少数研究已经调查了医院内抗结核治疗不合作的有关因素.目的:确定巴西里约热内卢市住院病人不合作治疗的有关因素.设计:病例对照研究.方法:所有选入研究的病例均在一所教学医院开始抗结核治疗.不合作病例定义为病人中断治疗60天仍未返回治疗.经过培训的卫生保健人员采用标准表格对病例组和对照组病人进行随访调查.结果:从1997年1月1日至12月31日共登记结核病人228例.经过查阅病历,剔除了其中的39例.对其余189例病人进行家庭访视;46例被确定为病例组,117例为对照组.在家庭访视以前观察到的抗结核治疗不合作者66(28.9%)例,家庭访视后不合作治疗者46例(20.2%).多元分析结果显示,治疗不合作的最主要预测指标是:1)没有提供返回治疗卡(OR=0.099;95%CI:0.008-1.2,P=0.07),2)病人感觉医生服务不周(OR=0.16;95%CI:0.33-0.015,P=0.001),3)未测血压(OR=0.072;95%CI:0.036-0.79,P=0.024). 结论:该医院的抗结核治疗不合作相关因素表明,非常需要系统的结核病控制规划.预计实施此类规划,采取特殊方法,将有助于强化抗结核治疗的完成率和治愈率.

  20. Evaluation of anti-tuberculosis antibodies in healthy contact and non-contacts persons

    International Nuclear Information System (INIS)

    This study was conducted to see the presence of the antimycobacterial antibodies in healthy household contacts of tuberculosis patients and healthy normal subjects who have never been in contact with tuberculosis patients. A total of 200 subjects, 120 with history of household contact and 80 without such history were included in the study. Routine Haematological investigations were performed and all the sera of 200 subjects were tested who 19M, 19G and IgA anti tuberculosis antibodies using ELISA technique. There was no difference in the average age of the household contacts and non-contacts. The complaints of pyrexia, night sweats and loss of weight was more in house hold contacts as compared to non-contacts. The awareness about BCG vaccination was equal among the household contacts and non-contacts. The combined serological positivity of the household contacts was 65.8% and the combined serological positivity for non-contacts was 34.1%. There was no statistically significant difference in the presence of 19M among household contacts as compared to non-contacts. However both IgG and 19A were present in significantly higher number of household contacts as compared to non contacts. This study concludes that the persons living in the house with a patient suffering from active pulmonary tuberculosis (household contact) have more chances of being infected with Mycobacterium tuberculosis as compared to the healthy non-contacts. (author)

  1. Preparation, characterization, and in vitro cytotoxicity evaluation of a novel anti-tuberculosis reconstruction implant.

    Directory of Open Access Journals (Sweden)

    JunFeng Dong

    Full Text Available BACKGROUND: Reconstruction materials currently used in clinical for osteoarticular tuberculosis (TB are unsatisfactory due to a variety of reasons. Rifampicin (RFP is a well-known and highly effective first-line anti-tuberculosis (anti-TB drug. Poly-DL-lactide (PDLLA and nano-hydroxyapatite (nHA are two promising materials that have been used both for orthopedic reconstruction and as carriers for drug release. In this study we report the development of a novel anti-TB implant for osteoarticular TB reconstruction using a combination of RFP, PDLLA and nHA. METHODS: RFP, PDLLA and nHA were used as starting materials to produce a novel anti-TB activity implant by the solvent evaporation method. After manufacture, the implant was characterized and its biodegradation and drug release profile were tested. The in vitro cytotoxicity of the implant was also evaluated in pre-osteoblast MC3T3-E1 cells using multiple methodologies. RESULTS: A RFP/PDLLA/nHA composite was successfully synthesized using the solvent evaporation method. The composite has a loose and porous structure with evenly distributed pores. The production process was steady and no chemical reaction occurred as proved by Fourier Transform Infrared Spectroscopy (FTIR and X-Ray Diffraction (XRD. Meanwhile, the composite blocks degraded and released drug for at least 12 weeks. Evaluation of in vitro cytotoxicity in MC3T3-E1 cells verified that the synthesized composite blocks did not affect cell growth and proliferation. CONCLUSION: It is feasible to manufacture a novel bioactive anti-TB RFP/PDLLA/nHA composite by the solvent evaporation method. The composite blocks showed appropriate properties such as degradation, drug release and biosafety to MC3T3-E1 cells. In conclusion, the novel composite blocks may have great potential for clinical applications in repairing bone defects caused by osteoarticular TB.

  2. Analysis of IL-6, STAT3 and HSPA1L gene polymorphisms in anti-tuberculosis drug-induced hepatitis in a nested case-control study.

    Directory of Open Access Journals (Sweden)

    Jing Wang

    Full Text Available To investigate the association of IL-6, STAT3 and HSPA1L polymorphisms with the risk of anti-tuberculosis drug-induced hepatitis (ATDH in Chinese Han population.The study was designed as a nested case-control study within a prospective cohort. Each case was matched with four controls by sex, age at baseline (±5 years, treatment history, disease severity, drug dosage and place of sample collection. Genetic polymorphisms of IL-6, STAT3 and HSPA1L were determined blindly by TaqMan single-nucleotide polymorphism (SNP genotyping assay. Odds ratio (OR with 95% confidence intervals (CIs was estimated by conditional logistic regression model to measure the association between selected SNPs and the risk of ATDH.A total of 89 incident ATDH cases and 356 ATDH-free controls were genotyped for IL-6 (rs2066992, rs2069837, rs1524107, STAT3 (rs1053004, rs1053023, rs1053005 and HSPA1L (rs2227956. In genotype analysis, no significant difference was observed in genotypes frequencies of the seven selected SNPs between case and control group after Bonferroni correction. In haplotype analysis, carriers with STAT3 GAT and AGC (rs1053023-rs1053005-rs1053004 haplotypes had a significantly higher risk of ATDH compared with wild-type haplotype (P<0.0001.This study suggested that genetic variants of STAT3 might contribute to ATDH susceptibility in Chinese Han population. Studies in larger, varied populations are required to confirm these findings.

  3. Expression of Mycobacterium tuberculosis NLPC/p60 family protein Rv0024 induce biofilm formation and resistance against cell wall acting anti-tuberculosis drugs in Mycobacterium smegmatis.

    Science.gov (United States)

    Padhi, Avinash; Naik, Sumanta Kumar; Sengupta, Srabasti; Ganguli, Geetanjali; Sonawane, Avinash

    2016-04-01

    Bacterial species are capable of living as biofilm and/or planktonic forms. Role of biofilms in the pathogenesis of several human pathogens is well established. However, in case of Mycobacterium tuberculosis (Mtb) infection the role of biofilms and the genetic requirements for biofilm formation remains largely unknown. We herein report that ectopic expression of Mtb Rv0024, encoding a putative peptidoglycan amidase, in non-pathogenic Mycobacterium smegmatis(Msm) strain (MsmRv0024) confer at least 10-fold increase in resistance against two prominent anti-tuberculosis drugs isoniazid and pyrazinamide. We further report that the development of resistance was due to significant increase in biofilm formation by Rv0024. Transmission electron microscopy revealed differences in cell surface architecture of MsmRv0024 when compared with Msm wild-type (WT) and vector control Msm pSMT3 (pSMT3) strains and this aggregation pattern was due to increased cell wall hydrophobicity, as determined by Bacterial adhesion to hydrocarbons assay (BATH). Confocal microscopy study showed increased adherence of MsmRv0024 bacteria to lung epithelial cells as compared to pSMT3 strain. However, infection studies showed no differences in host cell invasion and intracellular survival in mouse macrophages. We envision that Rv0024 may play a critical role in initial infection process, adherence to host cells and drug resistance. Thus, Rv0024 may be considered as a potential drug target for the treatment of tuberculosis. PMID:26706821

  4. Impact of glutathione S-transferase M1 and T1 on anti-tuberculosis drug-induced hepatotoxicity in Chinese pediatric patients.

    Directory of Open Access Journals (Sweden)

    Fang Liu

    Full Text Available Anti-tuberculosis drug induced hepatotoxicity (ATDH is a major adverse drug reaction associated for anti-tuberculosis therapy. The glutathione S-transferases (GST plays a crucial role in the detoxification of hepatotoxic metabolites of anti-tuberculosis drugs.An association between GSTM1/GSTT1 null mutations and increased risk of ATDH has been demonstrated in adults. Given the ethnic differences and developmental changes, our study aims to investigate the potential impacts of GSTM1/GSTT1 genotypes on the development of ATDH in Han Chinese children treated with anti-tuberculosis therapy.Children receiving anti-tuberculosis therapy with or without evidence of ATDH were considered as the cases or controls, respectively. The GSTM1 and GSTT1 genotyping were performed using the polymerase chain reaction.One hundred sixty-three children (20 cases and 143 controls with a mean age of 4.7 years (range: 2 months-14.1 years were included. For the GSTM1, 14 (70.0% cases and 96 (67.1% controls had homozygous null mutations. For the GSTT1, 13 (65.0% cases and 97 (67.8% controls had homozygous null mutations. Neither the GSTM1, nor the GSTT1 polymorphism was significantly correlated with the occurrence of ATHD.Our results did not support the GSTM1 and GSTT1 polymorphisms as the predictors of ADTH in Chinese Han children treated with anti-tuberculosis drugs. An age-related association between pharmacogenetics and ATHD need to be confirmed in the further study.

  5. Global Chemical Composition and Antioxidant and Anti-Tuberculosis Activities of Various Extracts of Globularia alypum L. (Globulariaceae Leaves

    Directory of Open Access Journals (Sweden)

    François Couderc

    2011-12-01

    Full Text Available In this work, an evaluation of the biological activities of Globularia alypum L. extracts and their global chemical composition was realized. Extracts from G. alypum were obtained by two extraction methods. The composition of polyphenols (8.5–139.95 g gallic acid equivalent/Kg of dry mass, tannins (1.39–18.65 g catechin equivalent/Kg of dry mass, anthocyanins (8.17–70.69 mg cyanidin equivalent/Kg of dry mass and flavonoids (0.31–19.28 g quercetin equivalent/Kg of dry mass was evaluated. The samples were subjected to a screening for their antioxidant activities using the DPPH· and ABTS·+ assays. For the first time, the anti-tuberculosis activity (H37Rv for G. alypum was tested against Mycobacterium tuberculosis. The strongest antioxidant activity was obtained for the methanol extract (IC50 = 15.58 ± 0.168 mg/L and the best anti-tuberculosis activity was obtained for the petroleum ether extract (IC50 = 77 mg/L. We have found a positive correlation between the total phenolics content and the antioxidant activity R2 = 0.88 (DPPH· and R2 = 0.97 (ABTS·+. We have found also a positive correlation between the flavonoid content and the antioxidant activity R2 = 0.91 (DPPH· and R2 = 0.91 (ABTS·+.

  6. Mortality among tuberculosis patients with acquired resistance to second-line anti-tuberculosis drugs — United States, 1993–2008

    Science.gov (United States)

    Ershova, Julia V.; Kurbatova, Ekaterina V.; Moonan, Patrick K.; Cegielski, J. Peter

    2016-01-01

    Background Resistance to second-line anti-tuberculosis drugs (SLD) severely compromises treatment options of drug-resistant tuberculosis (TB). We assessed the association between acquisition of resistance (AR) to second-line injectable drugs (SLI) or fluoroquinolones (FQ) and mortality among TB cases confirmed by positive culture results with available initial and final drug susceptibility test (DST) results. Methods We analyzed data from U.S. National TB Surveillance System, 1993–2008. Acquired resistance was defined as drug susceptibility at initial DST but resistance to the same drug at final DST. We compared survival with Kaplan-Meier curves and analyzed the association between AR and mortality using a univariate extended Cox proportional hazards model adjusted for age. Results Of 2,329 cases with both initial and final DST to SLI, 49 (2.1%) acquired resistance; 13/49 (26.5%) had treatment terminated by death versus 222 (10.0%) of those without AR to SLI (P<0.001). Of 1,187 cases with both initial and final DST to FQ, 32 (2.8%) acquired resistance; 12/32 (37.5%) had treatment terminated by death versus 121 (10.9%) of those without AR to FQ (P=0.001). Controlling for age, mortality was significantly greater among cases with AR to SLD than among cases without AR (adjusted hazard ratio (aHR)[SLI], 2.8; 95% confidence interval (CI),1.4–5.4; aHR[FQ], 1.9; 95% CI,1.0–3.5). MDR TB at treatment initiation, positive HIV status, and extrapulmonary disease were also significantly associated with mortality. Conclusion Mortality was significantly greater among TB cases with AR to SLD. Providers should consider AR to SLD early in treatment, monitor DST results, and avoid premature deaths. PMID:24846639

  7. The effects of CPAP treatment on task positive and default mode networks in obstructive sleep apnea patients: an fMRI study.

    Directory of Open Access Journals (Sweden)

    Olga Prilipko

    Full Text Available INTRODUCTION: Functional magnetic resonance imaging studies enable the investigation of neural correlates underlying behavioral performance. We investigate the effect of active and sham Continuous Positive Airway Pressure (CPAP treatment on working memory function of patients with Obstructive Sleep Apnea Syndrome (OSAS considering Task Positive and Default Mode networks (TPN and DMN. METHODS: An experiment with 4 levels of visuospatial n-back task was used to investigate the pattern of cortical activation in 17 men with moderate or severe OSAS before and after 2 months of therapeutic (active or sub-therapeutic (sham CPAP treatment. RESULTS: Patients with untreated OSAS had significantly less deactivation in the temporal regions of the DMN as compared to healthy controls, but activation within TPN regions was comparatively relatively preserved. After 2 months of treatment, active and sham CPAP groups exhibited opposite trends of cerebral activation and deactivation. After treatment, the active CPAP group demonstrated an increase of cerebral activation in the TPN at all task levels and of task-related cerebral deactivation in the anterior midline and medial temporal regions of the DMN at the 3-back level, associated with a significant improvement of behavioral performance, whereas the sham CPAP group exhibited less deactivation in the temporal regions of Default Mode Network and less Task Positive Network activation associated to longer response times at the 3-back. CONCLUSION: OSAS has a significant negative impact primarily on task-related DMN deactivation, particularly in the medial temporal regions, possibly due to nocturnal hypoxemia, as well as TPN activation, particularly in the right ventral fronto-parietal network. After 2 months of active nasal CPAP treatment a positive response was noted in both TPN and DMN but without compete recovery of existing behavioral and neuronal deficits. Initiation of CPAP treatment early in the course of the

  8. Formalizing Default Reasoning

    Institute of Scientific and Technical Information of China (English)

    1990-01-01

    Fuzzy set systems can be used to solve the problem with uncertain knowledge,and default logic can be used to solve the problem with incomplete knowledge,in some sense.In this paper,based on interval-valued fuzzy sets we introduce a method of inference which combines approximate reasoning an default ogic,and give the procedure of transforming monotonic reasoning into default reasoning.

  9. Bayesian default probability models

    OpenAIRE

    Andrlíková, Petra

    2014-01-01

    This paper proposes a methodology for default probability estimation for low default portfolios, where the statistical inference may become troublesome. The author suggests using logistic regression models with the Bayesian estimation of parameters. The piecewise logistic regression model and Box-Cox transformation of credit risk score is used to derive the estimates of probability of default, which extends the work by Neagu et al. (2009). The paper shows that the Bayesian models are more acc...

  10. Clinical Study of Drug-resistant Pulmonary Tuberculosis Treated by Combination of Anti-Tuberculosis Chemicals and Compound Astragalus Capsule(复方黄芪胶囊)

    Institute of Scientific and Technical Information of China (English)

    姜艳; 李新; 于志勇; 尹红义; 韩玉庆

    2004-01-01

    Objective: To observe and evaluate the therapeutic effect of anti-tuberculosis (anti-TB) chemicals and Compound Astragalus Capsule (CAC) in combinedly treating drug resistant pulmonary tuberculosis (DR-TB). Methods: Ninety-two patients with DR-TB were equally randomized into the treated group (treated with combination therapy) and the control group (treated with anti-TB chemicals alone). The therapeutic course for both groups was 18 months. Therapeutic effects between the two groups were compared at the end of the therapeutic course. Sputum bacterial negative rate, focal absorption effective rate, cavity closing rate, 10-day symptom improving rate, the incidence of adverse reaction and 2-year bacteriological recurrence rate between the two groups were compared. Results: In the treated group, the sputum bacterial negative conversion rate was 84. 8%, focal absorption effective rate 91.3 %, cavity closing rate 58. 7 % and 10-day symptom improving rate 54.4%, while in the control group, the corresponding rates were 65.2%,73.9 %, 37. 0% and 26.1%, respectively. Comparison between the groups showed significant difference in all the parameters ( P<0.05, P<0.05, P<0.05 and P<0.01 ). The incidence of adverse reaction and 2year bacteriological recurrence rate in the treated group were 23.9 % and 2.6 % respectively, while those in the control group 50.0% and 16.7%, which were higher than the former group with significant difference ( P<0.01 and P<0.05, respectively). Conclusion: The therapeutic effect of combined treatment with antiTB and CAC is superior to that of treatment with anti-TB chemicals alone, and the Chinese herbal medicine showed an adverse reaction alleviating effect, which provides a new therapy for DR-TB, and therefore, it is worth spreading in clinical practice.

  11. Bioautography with TLC-MS/NMR for Rapid Discovery of Anti-tuberculosis Lead Compounds from Natural Sources

    Science.gov (United States)

    Grzelak, Edyta M.; Hwang, Changhwa; Cai, Geping; Nam, Joo-Won; Choules, Mary P.; Gao, Wei; Lankin, David C.; McAlpine, James B.; Mulugeta, Surafel G.; Napolitano, José G.; Suh, Joo-Won; Yang, Seung Hwan; Cheng, Jinhua; Lee, Hanki; Kim, Jin-Yong; Cho, Sang-Hyun; Pauli, Guido F.; Franzblau, Scott G.; Jaki, Birgit U.

    2016-01-01

    While natural products constitute an established source of lead compounds, the classical iterative bioassay-guided isolation process is both time- and labor-intensive and prone to failing to identify active minor constituents. (HP)TLC-bioautography-MS/NMR, which combines cutting-edge microbiological, chromatographic, and spectrometric technologies, was developed to accelerate anti-tuberculosis (TB) drug discovery from natural sources by acquiring structural information at a very early stage of the isolation process. Using the avirulent, bioluminescent Mtb strain mc27000 luxABCDE, three variations of bioautography were evaluated and optimized for sensitivity in detecting anti-TB agents, including established clinical agents and new leads with novel mechanisms of action. Several exemplary applications of this approach to microbial extracts demonstrate its potential as a routine method in anti-TB drug discovery from natural sources.

  12. Mycobacterium tuberculosis whole genome sequencing and protein structure modelling provides insights into anti-tuberculosis drug resistance

    KAUST Repository

    Phelan, Jody

    2016-03-23

    Background Combating the spread of drug resistant tuberculosis is a global health priority. Whole genome association studies are being applied to identify genetic determinants of resistance to anti-tuberculosis drugs. Protein structure and interaction modelling are used to understand the functional effects of putative mutations and provide insight into the molecular mechanisms leading to resistance. Methods To investigate the potential utility of these approaches, we analysed the genomes of 144 Mycobacterium tuberculosis clinical isolates from The Special Programme for Research and Training in Tropical Diseases (TDR) collection sourced from 20 countries in four continents. A genome-wide approach was applied to 127 isolates to identify polymorphisms associated with minimum inhibitory concentrations for first-line anti-tuberculosis drugs. In addition, the effect of identified candidate mutations on protein stability and interactions was assessed quantitatively with well-established computational methods. Results The analysis revealed that mutations in the genes rpoB (rifampicin), katG (isoniazid), inhA-promoter (isoniazid), rpsL (streptomycin) and embB (ethambutol) were responsible for the majority of resistance observed. A subset of the mutations identified in rpoB and katG were predicted to affect protein stability. Further, a strong direct correlation was observed between the minimum inhibitory concentration values and the distance of the mutated residues in the three-dimensional structures of rpoB and katG to their respective drugs binding sites. Conclusions Using the TDR resource, we demonstrate the usefulness of whole genome association and convergent evolution approaches to detect known and potentially novel mutations associated with drug resistance. Further, protein structural modelling could provide a means of predicting the impact of polymorphisms on drug efficacy in the absence of phenotypic data. These approaches could ultimately lead to novel resistance

  13. Multiplex Assay of Second-Line Anti-Tuberculosis Drugs in Dried Blood Spots Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Lee, Kyunghoon; Jun, Sun Hee; Han, Minje; Song, Sang Hoon; Park, Jong Sun; Lee, Jae Ho; Park, Kyoung Un; Song, Junghan

    2016-09-01

    As dried blood spots (DBSs) have various advantages over conventional venous blood sampling, some assays for detection of one or two anti-tuberculosis (TB) drugs in DBSs have been developed. However, there are no assays currently available for the simultaneous measurement of three or more anti-TB drugs in DBSs. In this study, we developed and evaluated a multiplex method for detecting nine anti-TB drugs including streptomycin, kanamycin, clarithromycin, cycloserine, moxifloxacin, levofloxacin, para-aminosalicylic acid, prothionamide, and linezolid in DBSs by using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Seventy-nine patient samples of DBS were analyzed on the UPLC-MS/MS system. All drug concentrations were determined within 4 min, and assay performance was evaluated. All drugs were clearly separated without ion suppression. Within-run and between-run precisions were 1.7-13.0% and 5.7-17.0%, respectively, at concentrations representing low and high levels for the nine drugs. Lower limits of detection and quantification were 0.06-0.6 and 0.5-5.0 μg/mL, respectively. Linearity was acceptable at five level concentrations for each drug. Correlations between drug concentrations in plasma and DBSs by using Passing-Bablock regression and Pearson's rho (ρ 0.798-0.989) were acceptable. In conclusion, we developed a multiplex assay to measure nine second-line anti-TB drugs in DBSs successfully. This assay provided convenient and rapid drug quantification and could have applications in drug monitoring during treatment. PMID:27374716

  14. Morphologic and Functional Connectivity Alterations of Corticostriatal and Default Mode Network in Treatment-Naïve Patients with Obsessive-Compulsive Disorder

    Science.gov (United States)

    Hou, Jingming; Song, Lingheng; Zhang, Wei; Wu, Wenjing; Wang, Jian; Zhou, Daiquan; Qu, Wei; Guo, Junwei; Gu, Shanshan; He, Mei; Xie, Bing; Li, Haitao

    2013-01-01

    Background Previous studies have demonstrated that structural deficits and functional connectivity imbalances might underlie the pathophysiology of obsessive-compulsive disorder (OCD). The purpose of the present study was to investigate gray matter deficits and abnormal resting-state networks in patients with OCD and further investigate the association between the anatomic and functional alterations and clinical symptoms. Methods Participants were 33 treatment-naïve OCD patients and 33 matched healthy controls. Voxel-based morphometry was used to investigate the regions with gray matter abnormalities and resting-state functional connectivity analysis was further conducted between each gray matter abnormal region and the remaining voxels in the brain. Results Compared with healthy controls, patients with OCD showed significantly increased gray matter volume in the left caudate, left thalamus, and posterior cingulate cortex, as well as decreased gray matter volume in the bilateral medial orbitofrontal cortex, left anterior cingulate cortex, and left inferior frontal gyrus. By using the above morphologic deficits areas as seed regions, functional connectivity analysis found abnormal functional integration in the cortical-striatum-thalamic-cortical (CSTC) circuits and default mode network. Subsequent correlation analyses revealed that morphologic deficits in the left thalamus and increased functional connectivity within the CSTC circuits positively correlated with the total Y-BOCS score. Conclusion This study provides evidence that morphologic and functional alterations are seen in CSTC circuits and default mode network in treatment-naïve OCD patients. The association between symptom severity and the CSTC circuits suggests that anatomic and functional alterations in CSTC circuits are especially important in the pathophysiology of OCD. PMID:24358320

  15. Improvement of the productivity of ecumicin, a novel anti-tuberculosis agent, from new Nonomuraea sp. MJM5123.

    Science.gov (United States)

    Jin, Ying-Yu; Kim, Jin-Yong; Yang, Seung Hwan; Lee, Hanki; Suh, Joo-Won

    2016-05-01

    Ecumicin is a novel anti-tuberculosis agent produced by Nonomuraea sp. MJM5123 as a new strain of actinomycetes. First, in order to increase the cell mass of Nonomuraea sp. MJM5123, we optimized the culture conditions with regard to carbon and nitrogen sources. The cell mass of Nonomuraea sp. MJM5123 increased by approximately twofold when glucose and soybean flour were used as carbon and nitrogen sources, respectively. For maximum production of ecumicin, we optimized the culture conditions by adding amino acids as building blocks for ecumicin, by adding vegetable oils and by controlling the temperature and pH. Ecumicin production was two times higher with the addition of valine as the building blocks for ecumicin compared with the production in the absence of valine. Interestingly, with the addition of 1% corn oil, the production of ecumicin increased by 4.6-fold compared with the production in the absence of corn oil. Finally, by controlling the pH and temperature, we established an optimized culture condition in which Nonomuraea sp. MJM5123 produced 576 mg ecumicin per litre of medium, which is about 50 times higher than in the control medium at 30 °C and pH 7.0. PMID:26648116

  16. Sensitivity Pattern of Second Line Anti-Tuberculosis Drugs against Clinical Isolates of Multidrug Resistant Mycobacterium Tuberculosis

    International Nuclear Information System (INIS)

    Objective:To determine the current sensitivity pattern of second line anti-tuberculosis drugs against clinical isolates of Multidrug Resistant Mycobacterium tuberculosis (MDR-TB). Study Design: A cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from November 2011 to April 2013. Methodology: Samples received during the study period were processed on BACTEC MGIT 960 system for Mycobacterium tuberculosis (MTB) culture followed by first line drugs susceptibility testing of culture proven MTB isolates. On the basis of resistance to rifampicin and isoniazid, 100 clinical isolates of MDR-TB were further subjected to susceptibility testing against amikacin (AMK), capreomycin (CAP), ofloxacin (OFL) and ethionamide (ETH) as per standard BACTEC MGIT 960 instructions. Results: Out of 100 MDR-TB isolates, 62% were from male patients and 38% from female patients. 97% were sensitive to AMK, 53% to OFL, 87% to CAP; and 87% were sensitive to ETH. Conclusion: The majority of the MDR-TB isolates showed excellent sensitivity against AMK, CAP and ETH. However, sensitivity of MDR-TB isolates against fluoroquinolones like OFL was not encouraging. (author)

  17. Anti-tuberculosis drug induced hepatotoxicity among TB/HIV co-infected patients at Jimma University Hospital, Ethiopia: nested case-control study.

    Directory of Open Access Journals (Sweden)

    Alima Hassen Ali

    Full Text Available BACKGROUND: This study was carried out to determine the incidence and predictors of anti-tuberculosis drug induced hepatotoxicity among TB/HIV co-infected patients at Jimma University Hospital, Ethiopia. METHODS/PRINCIPAL FINDINGS: A nested case-control study was conducted by reviewing charts of all TB/HIV co-infected patients who commenced anti-TB treatment from January 2008 to December 2011 at Jimma University Hospital. Patients who had developed hepatotoxicity after at least 5 days of standard doses of anti-TB drug therapy were labeled as "cases" and those without hepatotoxicity were "controls". Each case with anti-TB drug induced hepatotoxicity was compared with 3 controls selected randomly from the cohort. From a cohort of 296 TB/HIV co-infected patients 8 were excluded from the study as the causality between anti-TB drugs and hepatotoxicity was not confirmed, 33 had developed hepatotoxicity. On bivariate logistic regression analysis, body mass index (BMI <18.5 Kg/m(2 [P = 0.01; OR (95%CI: 3.6 (1.4-9.5], disseminated pulmonary TB [P = 0.00; OR (95%CI: 5.6 (2.2-14.6], CD4 count ≤50 [P = 0.016; OR (95%CI: 3.6(1.27-10.23] and WHO stage 4 [P = 0.004, OR (95%CI: 3.8 (1.68-8.77] were significantly associated with anti-TB drug induced hepatotoxicity. Predictor variables with p-value <0.05 by bivariate analysis were analyzed using multivariable logistic regression analysis and identified disseminated pulmonary TB [P = 0.001; AOR (95%CI = 5.6 (2.1-15.0] and BMI <18.5 [P = 0.014; AOR (95%CI= 3.6 (1.3-10.1] as independent predictors of anti-TB drug induced hepatotoxicity. CONCLUSIONS: The incidence of anti-TB drug induced hepatotoxicity was 11.5%. The results suggest that in the presence of disseminated pulmonary TB and/or BMI <18.5 Kg/m(2, TB/HIV co-infected patients should be closely followed for the occurrence of hepatotoxicity during the intensive phase of TB treatment to prevent morbidity and mortality.

  18. Managing Default Risk

    OpenAIRE

    Anna Zabai

    2014-01-01

    High sovereign debt in advanced economies has recently revived the debate about the role of coordination problems and self-fulfilling beliefs as drivers of sovereign default risk. I show how default risk can be decomposed in a solvency-risk component and a coordination-risk component. I then study how fiscal policy can be effective in managing the risk of coordination and I characterise how the shape of the optimal policy is affected by the presence of this risk: making the deficit contingent...

  19. Student Loan Default.

    Science.gov (United States)

    Ginsberg, Edward; Ginsberg, Susan

    1989-01-01

    Most college students who default on federal loans come from low-income families and drop out of school within a year. Borrowers from more affluent families take out bigger loans, but stay in school longer, and are likely to secure steady employment and repay their loans. The Guaranteed Student Loan program seems designed for borrowers least…

  20. Molecular epidemiology study of Mycobacterium tuberculosis and its susceptibility to anti-tuberculosis drugs in Indonesia

    OpenAIRE

    Lisdawati, Vivi; Puspandari, Nelly; Rif’ati, Lutfah; Soekarno, Triyani; M, Melatiwati; K, Syamsidar; Ratnasari, Lies; Izzatun, Nur; Parwati, Ida

    2015-01-01

    Background Genotyping of Mycobacterium tuberculosis helps to understand the molecular epidemiology of tuberculosis and to address evolutionary questions about the disease spread. Certain genotypes also have implications for the spread of infection and treatment. Indonesia is a very diverse country with a population with multiple ethnicities and cultures and a history of many trade and tourism routes. This study describes the first attempt to map the molecular epidemiology of TB in the Indones...

  1. QTF-Gold assay for monitoring of anti-tuberculosis therapy in subjects with active TB

    Directory of Open Access Journals (Sweden)

    Ilaria Sauzullo

    2008-09-01

    Full Text Available Introduction: The identification and characterization of two M. tuberculosis-specific antigens (ESAT-6 and CFP- 10 has led to the development of a whole blood new generation of M. tuberculosis specific diagnostic tests, that have several advantages over tuberculin skin test (TST, in terms of higher specificity, better correlation with surrogate measures of exposure to M. tuberculosis in low-incidence setting, and less cross-reactivity with M. bovis (BCG vaccine and environmental mycobacteria.The role of these new tests in evaluating post-therapy tuberculosis eradication has not been investigated yet. Aim of this longitudinal study was to determinate changes of response to M. tuberculosis-specific antigens in patients during the standard tuberculosis treatment and to investigate the in vitro effects of tuberculosis drugs on the IFN-γ release. Methods: 23 individuals with active tuberculosis were enrolled and followed over time.They were tested with QuantiFERON TB-Gold (QFT-Gold at four time points: at diagnosis (t0, after 3 and 6 months of treatment (t1- t2 and at the end of the specific treatment (t3. Results: At baseline all patients were positive by QFT-Gold.At second time-point 17 out of 23 (74% were positive, at third time-point 11 of 23 (47% were positive, at treatment completion 3/23 (13% were positive.The conversion to negative response to M. tuberculosis-specific antigens was found in 87% patients analyzed after successful therapy. Longitudinal QFT-Gold testing shown a significant decrease (p<0.001 of IFN-γ response during the therapy. No inhibitory effect on IFN-γ release was noted in vitro for chemotherapy using at concentrations compatible with those achieved in serum of treated patients.We have revealed an inhibitory effect only at concentrations 2-3 times greater than those previously tested. Conclusion: A successful therapy for tuberculosis causes a significant decrease of the ESAT-6 and CFP-10 response and this data suggest

  2. Sovereign credit default swaps

    OpenAIRE

    Frank Packer; Chamaree Suthiphongchai

    2003-01-01

    This paper focuses on the sovereign segment of the credit default swap (CDS) market, examining data covering several years of quotes and trades from an important CDS inter-dealer broker. Compared to corporate or bank CDSs, sovereign CDSs are concentrated in fewer names and in contracts with reference assets of relatively short maturity, apparently a result of the fairly high proportion of low-rated sovereigns that tend to issue at short maturities. In addition, spreads on CDSs written on very...

  3. Role of polymorphic bile salt export pump (BSEP, ABCB11) transporters in anti-tuberculosis drug-induced liver injury in a Chinese cohort

    OpenAIRE

    Ru Chen; Jing Wang; Shaowen Tang; Yuan Zhang; Xiaozhen Lv; Shanshan Wu; Zhirong Yang; Yinyin Xia; Dafang Chen; Siyan Zhan

    2016-01-01

    Evidence indicates that the polymorphisms in bile salt export pump (BSEP, encoded by ABCB11) may play an important role in the development of anti-tuberculosis drug-induced liver injury (ATDILI) and we aim to investigate the association between genetic variants of ABCB11 and the risk of ATDILI in a Chinese cohort. A total of 89 tuberculosis patients with ATDILI and 356 matched ATDILI -free patients constituted cases and controls. Genetic polymorphisms of ABCB11 were determined by TaqMan singl...

  4. Improved consistency in dosing anti-tuberculosis drugs in Taipei, Taiwan.

    Directory of Open Access Journals (Sweden)

    Chen-Yuan Chiang

    Full Text Available BACKGROUND: It was reported that 35.5% of tuberculosis (TB cases reported in 2003 in Taipei City had no recorded pre-treatment body weight and that among those who had, inconsistent dosing of anti-TB drugs was frequent. Taiwan Centers for Disease Control (CDC have taken actions to strengthen dosing of anti-TB drugs among general practitioners. Prescribing practices of anti-TB drugs in Taipei City in 2007-2010 were investigated to assess whether interventions on dosing were effective. METHODOLOGY/PRINCIPAL FINDINGS: Lists of all notified culture positive TB cases in 2007-2010 were obtained from National TB Registry at Taiwan CDC. A medical audit of TB case management files was performed to collect pretreatment body weight and regimens prescribed at commencement of treatment. Dosages prescribed were compared with dosages recommended. The proportion of patients with recorded pre-treatment body weight was 64.5% in 2003, which increased to 96.5% in 2007-2010 (p<0.001. The proportion of patients treated with consistent dosing of a 3-drug fixed-dose combination (FDC increased from 73.9% in 2003 to 87.7% in 2007-2010 (p<0.001, and that for 2-drug FDC from 76.0% to 86.1% (p = 0.024, for rifampicin (RMP from 62.8% to 85.5% (p<0.001, and for isoniazid from 87.8% to 95.3% (p<0.001. In 2007-2010, among 2917 patients treated with either FDCs or RMP in single-drug preparation, the dosage of RMP was adequate (8-12 mg/kg in 2571(88.1% patients, too high in 282(9.7%, too low in 64(2.2%. In multinomial logistic regression models, factors significantly associated with adequate dosage of RMP were body weight and preparations of RMP. Patients weighting <40 kg (relative risk ratio (rrr 6010.5, 95% CI 781.1-46249.7 and patients weighting 40-49 kg (rrr 1495.3, 95% CI 200.6-11144.6 were more likely to receive higher-than-recommended dose of RMP. CONCLUSIONS/SIGNIFICANCE: Prescribing practice in the treatment of TB in Taipei City has remarkably improved after health

  5. Encapsulation of Anti-Tuberculosis Drugs within Mesoporous Silica and Intracellular Antibacterial Activities

    Directory of Open Access Journals (Sweden)

    Xin Xia

    2014-09-01

    Full Text Available Tuberculosis is a major problem in public health. While new effective treatments to combat the disease are currently under development, they tend suffer from poor solubility often resulting in low and/or inconsistent oral bioavailability. Mesoporous materials are here investigated in an in vitro intracellular assay, for the effective delivery of compound PA-824; a poorly soluble bactericidal agent being developed against Tuberculosis (TB. Mesoporous materials enhance the solubility of PA-824; however, this is not translated into a higher antibacterial activity in TB-infected macrophages after 5 days of incubation, where similar values are obtained. The lack of improved activity may be due to insufficient release of the drug from the mesopores in the context of the cellular environment. However, these results show promising data for the use of mesoporous particles in the context of oral delivery with expected improvements in bioavailability.

  6. The anti-tuberculosis agents under development and the challenges ahead.

    Science.gov (United States)

    Kumar, Deepak; Negi, Beena; Rawat, Diwan S

    2015-01-01

    Tuberculosis (TB) is a serious health problem causing 1.5 million deaths worldwide. After the discovery of first-line anti-TB drugs, the mortality rate declined sharply, however, the emergence of drug-resistant strains and HIV co-infection have led to increased incidence of this disease. A number of new potential antitubercular drug candidates with novel modes of action have entered clinical trials in recent years. Compounds such as gatifloxacin, moxifloxacin and linezolid, the already known antibiotics are currently being evaluated for their anti-TB activity. OPC-67683 and TMC207 have been approved for the treatment of MDR-TB patients recently, while PA-824, SQ109, PNU-100480, AZD5847, LL3858, SQ609, SQ641, BTZ043, DC-159a, CPZEN-45, Q-203, DNB1, TBA-354 are in various phases of clinical and preclinical developments. This review evaluates the current status of TB drug development and future aspects. PMID:26505682

  7. Role of polymorphic bile salt export pump (BSEP, ABCB11) transporters in anti-tuberculosis drug-induced liver injury in a Chinese cohort.

    Science.gov (United States)

    Chen, Ru; Wang, Jing; Tang, Shaowen; Zhang, Yuan; Lv, Xiaozhen; Wu, Shanshan; Yang, Zhirong; Xia, Yinyin; Chen, Dafang; Zhan, Siyan

    2016-01-01

    Evidence indicates that the polymorphisms in bile salt export pump (BSEP, encoded by ABCB11) may play an important role in the development of anti-tuberculosis drug-induced liver injury (ATDILI) and we aim to investigate the association between genetic variants of ABCB11 and the risk of ATDILI in a Chinese cohort. A total of 89 tuberculosis patients with ATDILI and 356 matched ATDILI -free patients constituted cases and controls. Genetic polymorphisms of ABCB11 were determined by TaqMan single-nucleotide polymorphism (SNP) genotyping assay. Odds ratio (OR) with 95% confidence intervals (CIs) was estimated by conditional logistic regression model. There were no significant differences in genotype frequencies of ABCB11 between cases and controls. In the subgroup analysis, polymorphisms of rs2287616 were found to be associated with cholestatic/mixed pattern of liver injury under dominant and addictive model (OR = 3.84, 95% CI:1.16-12.75, P = 0.028 and OR = 2.51, 95% CI:1.12-5.62, P = 0.025, respectively), however the significance disappeared after Bonferroni correction. This study suggested that genetic variants of ABCB11 gene might contribute to anti-tuberculosis drug-induced cholestatic liver injury in Chinese patients. Studies in larger, varied populations are required to confirm these findings. PMID:27293027

  8. Sunk Costs and Mortgage Default

    OpenAIRE

    Green, Richard K.; Eric Rosenblatt; Vincent Yao

    2010-01-01

    In this paper, we estimate default hazard functions that include standard variables along with borrowers sunk cost: i.e., down payment at loan origination. After testing large numbers of specifications, we find that after controlling for mark-to-market loan-to-value, initial combined loan to value remains an important predictor of default. We also find, contrary to Guiso, Sapienze and Zingales (2009), that there is not a specific point at which one observes a discontinuous default probability...

  9. Pricing options on defaultable stocks

    OpenAIRE

    Tayibov, Khayyam

    2012-01-01

    In this note, we develop stock option price approximations for a model which takes both the risk o default and the stochastic volatility into account. We also let the intensity of defaults be influenced by the volatility. We show that it might be possible to infer the risk neutral default intensity from the stock option prices. Our option price approximation has a rich implied volatility surface structure and fits the data implied volatility well. Our calibration exercise shows that an effect...

  10. Defaulters among lung cancer patients in a suburban district in a developing country

    Directory of Open Access Journals (Sweden)

    T H Ng

    2012-01-01

    Full Text Available Introduction: This study was carried out to determine the prevalence, patient′s characteristic and reasons for defaulting follow-up and treatment among patients with lung cancer. Methods: Patients with histologically confirmed lung cancer were recruited. Patient′s detailed demographic data, occupation, socioeconomic status, and educational level of both the patients and their children were recorded. Defaulters were classified as either intermittent or persistent defaulters. By using Chi-square test, defaulter status was compared with various demographic and disease characteristic factors. The reasons for default were determined. Results: Ninety five patients were recruited. Among them, 81.1% patients were males; 66.3% were Malays. The mean age (SD was 60 ± 10.5 years. About 46.3% of the patients had Eastern Cooperation Oncology Group (ECOG functional status 0/1 and 96.8% of the patients presented with advanced stage (Stage 3b or 4. Overall, 20 patients (21.1% were defaulters (35.0% intermittent defaulters; 65.0% persistent defaulters. Among the intermittent defaulters, 8 patients defaulted once and one patient defaulted 3 times. Among the 20 defaulters, only 2 (10% patients turned up for the second follow-up appointment after telephone reminder. Two main reasons for default were ′too ill to come′ (38.5.5% and logistic difficulties (23.1%. No correlation was found between patient education, children education, income, ECOG status, stage of the disease, race, and gender with the defaulter rate. Conclusion: Defaulter rate among lung cancer patients was 21.1%. Children education level is the only significant factor associated with the defaulter rate.

  11. Anti-tuberculosis Drugs with Novel Mechanism of Action%具有新型作用机制的抗结核药物

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Tuberculosis is one of major health problems worldwide. Approximately 1.8 mil ion people died from Tuberculosis each year which has become a global public health issue. Recently the emergence of drug resistant strains and HIV co-infection has resulted in a high incidence. As a result, there is an urgent need for us to understand the resistance mechanism and discover new anti-tuberculosis drugs. A number of new potential anti-tuberculosis drug candidates with novel modes of action have entered clinical trials in recent years. These agents are most likely to be effective against resistant strains. The paper summarized structure-activity relationships, in vitro and in vivo activity, pharmacokinetics, mechanism of action and combination regimens about several novel anti-tuberculosis drugs.%  结核病(Tuberculosis)是世界范围里的主要疾病之一,近年来,每年约有180万人死于结核病,结核病已经成为全球性的公众健康问题。近年来药物耐受以及伴有 HIV 感染的结核病发病率急剧增加,迫切需要深入了解目前抗结核药物的作用机制及耐药机制,以指导开发对持留菌和耐药菌更加有效的新型药物。近年来,一批具有全新作用机制的抗结核候选药物相继进入了临床研究,并且这些药物对耐药株表现出有效的抑制活性。文章对几类新型抗结核药物的化学结构、作用机制、构效关系、抗结核活性以及临床应用进行了综述。

  12. Reagent Precoated Targets for Rapid In-Tissue Derivatization of the Anti-Tuberculosis Drug Isoniazid Followed by MALDI Imaging Mass Spectrometry

    Science.gov (United States)

    Manier, M. Lisa; Reyzer, Michelle L.; Goh, Anne; Dartois, Veronique; Via, Laura E.; Barry, Clifton E.; Caprioli, Richard M.

    2011-08-01

    Isoniazid (INH) is an important component of front-line anti-tuberculosis therapy with good serum pharmacokinetics but unknown ability to penetrate tuberculous lesions. However, endogenous background interferences hinder our ability to directly analyze INH in tissues. Chemical derivatization has been successfully used to measure isoniazid directly from tissue samples using matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS). MALDI targets were pretreated with trans-cinnamaldehyde (CA) prior to mounting tissue slices. Isoniazid present in the tissues was efficiently derivatized and the INH-CA product measured by MS/MS. Precoating of MALDI targets allows the tissues to be directly thaw-mounted and derivatized, thus simplifying the preparation. A time-course series of tissues from tuberculosis infected/INH dosed animals were assayed and the MALDI MS/MS response correlates well with the amount of INH determined to be in the tissues by high-performance liquid chromatography (HPLC)-MS/MS.

  13. LDC Borrowing with Default Risk

    OpenAIRE

    Jeffrey Sachs; Daniel Cohen

    1982-01-01

    This paper presents a theoretical model to describe the effects of default risk on international lending to LDC sovereign borrowers. The threat of defaults in international lending is shown to give rise to many characteristics of the syndicated loan market: (1) quantity rationing of loans; (2) LDC policies designed to enhance creditworthiness; (3) prevalence of short maturities on international loans; and (4) a prevalence of bank lending relative to bond-market lending

  14. Regular Disjunction-Free Default Theories

    Institute of Scientific and Technical Information of China (English)

    Xi-Shun Zhao

    2004-01-01

    In this paper, the class of regular disjunction-free default theories is introduced and investigated.A transformation from regular default theories to normal default theories is established. The initial theory and the transformed theory have the same extensions when restricted to old variables. Hence, regular default theories enjoy some similar properties (e.g., existence of extensions, semi-monotonicity) as normal default theories. Then,a new algorithm for credulous reasoning of regular theories is developed. This algorithm runs in a time not more than O(1.45n), where n is the number of defaults. In case of regular prerequisite-free or semi-2CNF default theories, the credulous reasoning can be solved in polynomial time. However, credulous reasoning for semi-Horn default theories is shown to be NP-complete although it is tractable for Horn default theories. Moreover, skeptical reasoning for regular unary default theories is co-NP-complete.

  15. Regular Disjunction-Free Default Theories

    Institute of Scientific and Technical Information of China (English)

    Xi-ShunZhao

    2004-01-01

    In this paper, the class of regular disjunction-free default theories is introduced and investigated. A transformation from regular default theories to normal default theories is established. The initial theory and the transformed theory have the same extensions when restricted to old variables. Hence, regular default theories enjoy some similar properties (e.g., existence of extensions, semi-monotonicity) as normal default theories. Then, a new algorithm for credulous reasoning of regular theories is developed. This algorithm runs in a time not more than O(1.45n), where n is the number of defaults. In case of regular prerequisite-free or semi-2CNF default theories, the credulous reasoning can be solved in polynomial time. However, credulous reasoning for semi-Horn default theories is shown to be NP-complete although it is tractable for Horn default theories. Moreover, skeptical reasoning for regular unary default theories is co-NP-complete.

  16. Sovereign default and macroeconomic tipping points

    OpenAIRE

    Joy, Mark

    2012-01-01

    This paper examines the impact of macroeconomic fundamentals on the probability of sovereign default and the probability of exit from default while allowing explicitly for model uncertainty. Model uncertainty is addressed by employing Bayesian model-averaging techniques, averaging over a very large number of different empirical models that each endeavour to explain entry to and exit from periods of sovereign default for defaulting countries over the period 1975 to 2010. Default probabilities ...

  17. Default and Credit Constraint in General equilibrium

    OpenAIRE

    Xavier Ragot; François Le Grand

    2011-01-01

    We study an economy where infinitely living agents face uninsurable shocks and are allowed default on their debt. After having defaulted, agents are excluded from the economy. We present a equilibrium definition allowing for both credit constraints and default inequilibrium. Indeed, existing theories introduce either default of credit constraint in general equilibrium, but never both. We prove that the optimal allocation includes both credit constraints and default, while the market allocatio...

  18. Is there an omission effect in prosocial behavior beyond the default effect?

    OpenAIRE

    Gärtner, Manja; Sandberg, Anna

    2014-01-01

    We test whether there is an omission effect in prosocial choices beyond the default effect. To isolate the omission effect from the default effect, we conduct two incentivized resource allocation experiments. In these experiments, participants choose between two allocations of money between themselves and another participant: one selfish allocation and one fair allocation. Our treatments manipulate whether a selfish default is chosen passively or actively. We find no evidence that the distinc...

  19. Robustness of Distance-to-Default

    DEFF Research Database (Denmark)

    Jessen, Cathrine; Lando, David

    2013-01-01

    Distance-to-default is a remarkably robust measure for ranking firms according to their risk of default. The ranking seems to work despite the fact that the Merton model from which the measure is derived produces default probabilities that are far too small when applied to real data. We use...... simulations to investigate the robustness of the distance-to-default measure to different model specifications. Overall we find distance-to-default to be robust to a number of deviations from the simple Merton model that involve different asset value dynamics and different default triggering mechanisms. A...... notable exception is a model with stochastic volatility of assets. In this case both the ranking of firms and the estimated default probabilities using distance-to-default perform significantly worse. We therefore propose a volatility adjustment of the distance-to-default measure, that significantly...

  20. Numerical ability predicts mortgage default.

    Science.gov (United States)

    Gerardi, Kristopher; Goette, Lorenz; Meier, Stephan

    2013-07-01

    Unprecedented levels of US subprime mortgage defaults precipitated a severe global financial crisis in late 2008, plunging much of the industrialized world into a deep recession. However, the fundamental reasons for why US mortgages defaulted at such spectacular rates remain largely unknown. This paper presents empirical evidence showing that the ability to perform basic mathematical calculations is negatively associated with the propensity to default on one's mortgage. We measure several aspects of financial literacy and cognitive ability in a survey of subprime mortgage borrowers who took out loans in 2006 and 2007, and match them to objective, detailed administrative data on mortgage characteristics and payment histories. The relationship between numerical ability and mortgage default is robust to controlling for a broad set of sociodemographic variables, and is not driven by other aspects of cognitive ability. We find no support for the hypothesis that numerical ability impacts mortgage outcomes through the choice of the mortgage contract. Rather, our results suggest that individuals with limited numerical ability default on their mortgage due to behavior unrelated to the initial choice of their mortgage. PMID:23798401

  1. Testing the effect of defaults on the thermostat settings of OECD employees

    International Nuclear Information System (INIS)

    We describe a randomized controlled experiment in which the default settings on office thermostats in an OECD office building were manipulated during the winter heating season, and employees' chosen thermostat setting observed over a 6-week period. Using difference-in-differences, panel, and censored regression models (to control for maximum allowable thermostat settings), we find that a 1 °C decrease in the default caused a reduction in the chosen setting by 0.38 °C, on average. Sixty-five percent of this effect could be attributed to office occupant behavior (p-value = 0.044). The difference-in-differences models show that small decreases in the default (1°) led to a greater reduction in chosen settings than large decreases (2°). We also find that office occupants who were more apt to adjust their thermostats prior to the intervention were less susceptible to the default. We conclude that this kind of intervention can increase building-level energy efficiency, and discuss potential explanations and broader policy implications of our findings. - Highlights: • We conduct a randomized controlled trial to test if thermostat defaults affect agent behavior. • Two treatments (schedules of default settings) were tested against a control for 6 weeks at OECD. • Small changes in defaults had a greater effect on chosen settings than larger changes in defaults. • Occupants who frequently changed their thermostats in baseline were less affected by defaults. • Thermostat defaults in office environments can be manipulated to increase energy efficiency

  2. A note on neglect defaulting

    Directory of Open Access Journals (Sweden)

    Howard Margolis

    2008-04-01

    Full Text Available I introduce the notion of ``neglect defaulting,'' which labels the propensity to neglect possibilities which are ordinarily sensibly neglected. In familiar contexts we are well-tuned to recognize when to override the default. But outside the range of familiar experience --- here in the artificial context of puzzles --- these ordinarily benign defaults can make it difficult for even sophisticated subjects, such as readers of this note, to avoid responses which on reflection will be seen as obviously mistaken. A detail of particular importance is that, although subjects are easily prompted to take one step in the direction of reaching a sound response, the tendency to then neglect to consider that another step may be needed is remarkably strong. In each of the five examples the needed but usually neglected second step is quite trivial. Concluding remarks point to consequences for larger questions outside the range of familiar experience, in politics and other contexts out of scale with everyday experience.

  3. Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance.

    Directory of Open Access Journals (Sweden)

    Miriam Bobadilla-del Valle

    2015-09-01

    Full Text Available Mycobacterium tuberculosis causes the majority of tuberculosis (TB cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City.Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory's database for the 2000-2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X(2trend, p<0.001. Primary STR resistance was higher among M. bovis compared with M. tuberculosis isolates (10.9% vs.3.4%, p<0.001. Secondary multidrug resistance (MDR rates were 38.5% and 34.4% for M. bovis and M. tuberculosis, respectively (p = 0.637. A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000-2004 vs. 7.6% in 2010-2014; p = 0.02.There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance.

  4. Trends of Mycobacterium bovis Isolation and First-Line Anti-tuberculosis Drug Susceptibility Profile: A Fifteen-Year Laboratory-Based Surveillance

    Science.gov (United States)

    Bobadilla-del Valle, Miriam; Torres-González, Pedro; Cervera-Hernández, Miguel Enrique; Martínez-Gamboa, Areli; Crabtree-Ramirez, Brenda; Chávez-Mazari, Bárbara; Ortiz-Conchi, Narciso; Rodríguez-Cruz, Luis; Cervantes-Sánchez, Axel; Gudiño-Enríquez, Tomasa; Cinta-Severo, Carmen; Sifuentes-Osornio, José; Ponce de León, Alfredo

    2015-01-01

    Background Mycobacterium tuberculosis causes the majority of tuberculosis (TB) cases in humans; however, in developing countries, human TB caused by M. bovis may be frequent but undetected. Human TB caused by M. bovis is considered a zoonosis; transmission is mainly through consumption of unpasteurized dairy products, and it is less frequently attributed to animal-to-human or human-to-human contact. We describe the trends of M. bovis isolation from human samples and first-line drug susceptibility during a 15-year period in a referral laboratory located in a tertiary care hospital in Mexico City. Methodology/Principal Findings Data on mycobacterial isolates from human clinical samples were retrieved from the laboratory’s database for the 2000–2014 period. Susceptibility to first-line drugs: rifampin, isoniazid, streptomycin (STR) and ethambutol was determined. We identified 1,165 isolates, 73.7% were M. tuberculosis and 26.2%, M. bovis. Among pulmonary samples, 16.6% were M. bovis. The proportion of M. bovis isolates significantly increased from 7.8% in 2000 to 28.4% in 2014 (X2trend, p<0.001). Primary STR resistance was higher among M. bovis compared with M. tuberculosis isolates (10.9% vs.3.4%, p<0.001). Secondary multidrug resistance (MDR) rates were 38.5% and 34.4% for M. bovis and M. tuberculosis, respectively (p = 0.637). A rising trend of primary STR monoresistance was observed for both species (3.4% in 2000–2004 vs. 7.6% in 2010–2014; p = 0.02). Conclusions/Significance There is a high prevalence and a rising trend of M. bovis isolates in our region. The proportion of pulmonary M. bovis isolates is higher than in previous reports. Additionally, we report high rates of primary anti-tuberculosis resistance and secondary MDR in both M. tuberculosis and M. bovis. This is one of the largest reports on drug susceptibility of M. bovis from human samples and shows a significant proportion of first-line anti-tuberculosis drug resistance. PMID:26421930

  5. Default Distribution and Credit Market Implications

    CERN Document Server

    Mori, S; Kitsukawa, K

    2006-01-01

    We study the implied default distributions for the iTraxx-CJ tranches by means of the Principle of Maximum Entropy. The profiles are quite different from those of some popular probabilistic models. We analyze their correlation structures, the conditional default probabilities $p_{ij}$ and conditional default correlations $\\rho_{ij}$. Here the subscript ${}_{ij}$ means that the default probability and correlation are estimated under $i$ obligors are defaulted and $j$ obligors are non-defaulted among $N$ obligors. The implied default distribution, $\\rho_{n0}$ shows singular behavior, jumps high and then decreases rapidly to zero with $n$. Correspondingly $p_{n0}$ increases with $n$ and saturates to some maximum value below 1. Such a behavior implies that the credit market expects a middle scale avalanche. We also discuss the ``True'' default correlation implied by the market quotes.

  6. 45 CFR 672.10 - Default order.

    Science.gov (United States)

    2010-10-01

    ... respondent unless the complainant presents sufficient evidence to the Presiding Officer to establish a prima facie case against the respondent. Any motion for a default order shall include a proposed default...

  7. Development of a Nafion/MWCNT-SPCE-Based Portable Sensor for the Voltammetric Analysis of the Anti-Tuberculosis Drug Ethambutol

    Directory of Open Access Journals (Sweden)

    Rosa A. S. Couto

    2016-06-01

    Full Text Available Herein we describe the development, characterization and application of an electrochemical sensor based on the use of Nafion/MWCNT-modified screen-printed carbon electrodes (SPCEs for the voltammetric detection of the anti-tuberculosis (anti-TB drug ethambutol (ETB. The electrochemical behaviour of the drug at the surface of the developed Nafion/MWCNT-SPCEs was studied through cyclic voltammetry (CV and square wave voltammetry (SWV techniques. Electrochemical impedance spectroscopy (EIS and scanning electron microscopy (SEM were employed to characterize the modified surface of the electrodes. Results showed that, compared to both unmodified and MWCNTs-modified SPCEs, negatively charged Nafion/MWCNT-SPCEs remarkably enhanced the electrochemical sensitivity and selectivity for ETB due to the synergistic effect of the electrostatic interaction between cationic ETB molecules and negatively charged Nafion polymer and the inherent electrocatalytic properties of both MWCNTs and Nafion. Nafion/MWCNT-SPCEs provided excellent biocompatibility, good electrical conductivity, low electrochemical interferences and a high signal-to-noise ratio, providing excellent performance towards ETB quantification in microvolumes of human urine and human blood serum samples. The outcomes of this paper confirm that the Nafion/MWCNT-SPCE-based device could be a potential candidate for the development of a low-cost, yet reliable and efficient electrochemical portable sensor for the low-level detection of this antimycobacterial drug in biological samples.

  8. Development of a Nafion/MWCNT-SPCE-Based Portable Sensor for the Voltammetric Analysis of the Anti-Tuberculosis Drug Ethambutol.

    Science.gov (United States)

    Couto, Rosa A S; Quinaz, Maria Beatriz

    2016-01-01

    Herein we describe the development, characterization and application of an electrochemical sensor based on the use of Nafion/MWCNT-modified screen-printed carbon electrodes (SPCEs) for the voltammetric detection of the anti-tuberculosis (anti-TB) drug ethambutol (ETB). The electrochemical behaviour of the drug at the surface of the developed Nafion/MWCNT-SPCEs was studied through cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. Electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were employed to characterize the modified surface of the electrodes. Results showed that, compared to both unmodified and MWCNTs-modified SPCEs, negatively charged Nafion/MWCNT-SPCEs remarkably enhanced the electrochemical sensitivity and selectivity for ETB due to the synergistic effect of the electrostatic interaction between cationic ETB molecules and negatively charged Nafion polymer and the inherent electrocatalytic properties of both MWCNTs and Nafion. Nafion/MWCNT-SPCEs provided excellent biocompatibility, good electrical conductivity, low electrochemical interferences and a high signal-to-noise ratio, providing excellent performance towards ETB quantification in microvolumes of human urine and human blood serum samples. The outcomes of this paper confirm that the Nafion/MWCNT-SPCE-based device could be a potential candidate for the development of a low-cost, yet reliable and efficient electrochemical portable sensor for the low-level detection of this antimycobacterial drug in biological samples. PMID:27376291

  9. Firm default and aggregate fluctuations

    NARCIS (Netherlands)

    Jacobson, Tor; Linde, Jesper; Roszbach, Kasper

    2013-01-01

    This paper studies the relationship between macroeconomic fluctuations and corporate defaults while conditioning on industry affiliation and an extensive set of firm-specific factors. By using a panel data set for virtually all incorporated Swedish businesses over 1990-2009, a period which includes

  10. Constraints on Extensions of a Default Theory

    Institute of Scientific and Technical Information of China (English)

    SU Kaile

    2001-01-01

    In this paper, the representability of a family of theories as the set of extensions of a default theory is studied. First, a new necessary condition is given for the representability by means of general default theories; then a sufficient one is presented. The families of theories represented by default theories are also fully characterized. Finally, the paper gives an example of denumerable families of mutually inconsistent theories that are represented by a default theory but not by normal ones.

  11. Robustness of Distance-to-Default

    DEFF Research Database (Denmark)

    Jessen, Cathrine; Lando, David

    2015-01-01

    Distance-to-default (DD) is a measure of default risk derived from observed stock prices and book leverage using the structural credit risk model of Merton (1974). Despite the simplifying assumptions that underlie its derivation, DD has proven empirically to be a strong predictor of default. We u...

  12. Sato Processes in Default Modeling

    DEFF Research Database (Denmark)

    Kokholm, Thomas; Nicolato, Elisa

    2010-01-01

    In reduced form default models, the instantaneous default intensity is the classical modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature tends to specify the cumulative...... hazard process directly. Within this framework we present a new model class where cumulative hazards are described by self-similar additive processes, also known as Sato processes. Furthermore, we analyze specifications obtained via a simple deterministic time-change of a homogeneous Lévy process. While...... intensity and a recently proposed class of intensity models based on Ornstein-Uhlenbeck type processes. It is shown that the time-inhomogeneous Lévy models achieve comparable calibration errors with fewer parameters, and with more stable parameter estimates over time. However, the calibration performance...

  13. Sato Processes in Default Modeling

    DEFF Research Database (Denmark)

    Kokholm, Thomas; Nicolato, Elisa

    In reduced form default models, the instantaneous default intensity is classically the modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature has shown a tendency towards...... specifying the cumulative hazard process directly. Within this framework we present a new model class where cumulative hazards are described by self-similar additive processes, also known as Sato processes. Furthermore we also analyze specifications obtained via a simple deterministic time...... with those of a recently proposed class of intensity models based on Ornstein-Uhlenbeck type processes. It is shown how the time-inhomogeneous Levy models achieve comparable calibration errors with fever parameters, and with more stable parameter estimates over time. However, the calibration performances...

  14. Design of the Anti-tuberculosis Drugs induced Adverse Reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS)

    OpenAIRE

    He Ping; Yang Li; Chen Da; Wang Hong; Gao Wei; Zhu Li; Zhou Lin; Chen Yi; Tu,, Y.; Yuan Yan; Wang Xiao; Liu Fei; Hu Dai; Xia Yin; Li Xiao

    2010-01-01

    Abstract Background More than 1 million tuberculosis (TB) patients are receiving the standard anti-TB treatment provided by China National Tuberculosis Prevention and Control Scheme (CNTS) in China every year. Adverse reactions (ADRs) induced by anti-TB drugs could both do harm to patients and lead to anti-TB treatment failure. The ADACS aimed to explore ADRs' incidences, prognoses, economical and public health impacts for TB patients and TB control, and build a DNA bank of TB patients. Metho...

  15. Default-risky Sovereign Debt

    OpenAIRE

    Wiggers, Andreas

    2002-01-01

    Not only corporate but also sovereign debtors, in particular developing countries, may get into financial difficulties. Contrary to corporate issuers, they decide themselves if they continue to fulfill their debt obligations or convert their debt. I analyze the value of a default-risky sovereign bond in a setting in which foreign trade is reduced in case the country does not fulfill its obligations. Comparing the costs of debt service with the value of the punishment via foreign trade, the co...

  16. Availability of second-line drugs and anti-tuberculosis drug susceptibility testing in China: a situational analysis

    NARCIS (Netherlands)

    G.X. He; S. van den Hof; M.W. Borgdorff; M.J. van der Werf; S.M. Cheng; Y.L. Hu; L.X. Zhang; L.X. Wang

    2010-01-01

    OBJECTIVE: To assess the availability of second-line drugs (SLDs) and the use of drug susceptibility testing (DST) results for the treatment of tuberculosis (TB) in China. DESIGN: Cross-sectional survey in 4675 health care facilities, 1960 of which have a dedicated TB clinic, in 12 provinces in Chin

  17. Design of the Anti-tuberculosis Drugs induced Adverse Reactions in China National Tuberculosis Prevention and Control Scheme Study (ADACS

    Directory of Open Access Journals (Sweden)

    He Ping

    2010-05-01

    Full Text Available Abstract Background More than 1 million tuberculosis (TB patients are receiving the standard anti-TB treatment provided by China National Tuberculosis Prevention and Control Scheme (CNTS in China every year. Adverse reactions (ADRs induced by anti-TB drugs could both do harm to patients and lead to anti-TB treatment failure. The ADACS aimed to explore ADRs' incidences, prognoses, economical and public health impacts for TB patients and TB control, and build a DNA bank of TB patients. Methods/Design Multiple study designs were adopted. Firstly, a prospective cohort with 4488 sputum smears positive pulmonary tuberculosis patients was established. Patients were followed up for 6-9 months in 52 counties of four regions. Those suspected ADRs should be checked and confirmed by Chinese State Food and Drug Administration (SFDA. Secondly, if the suspected ADR was anti-TB drug induced liver injury (ATLI, a nested case-control study would be performed which comprised choosing a matched control and doing a plus questionnaire inquiry. Thirdly, health economical data of ADRs would be collected to analyze financial burdens brought by ADRs and cost-effectiveness of ADRs' treatments. Fourthly, a drop of intravenous blood for each patient was taken and saved in FTA card for DNA banking and genotyping. Finally, the demographic, clinical, environmental, administrative and genetic data would be merged for the comprehensive analysis. Discussion ADACS will give an overview of anti-TB drugs induced ADRs' incidences, risk factors, treatments, prognoses, and clinical, economical and public health impacts for TB patients applying CNTS regimen in China, and provide suggestions for individualized health care and TB control policy.

  18. Development of a prediction system for anti-tuberculosis drug-induced liver injury in Japanese patients

    Science.gov (United States)

    Mushiroda, Taisei; Yanai, Hideki; Yoshiyama, Takashi; Sasaki, Yuka; Okumura, Masao; Ogata, Hideo; Tokunaga, Katsushi

    2016-01-01

    Drug-induced liver injury (DILI) is a common adverse drug reaction in patients receiving antituberculosis (anti-TB) treatment. Among the anti-TB agents, isoniazid (INH) is the primary drug that causes hepatotoxicity in TB patients with DILI. Previous reports in several populations have consistently demonstrated an association between polymorphisms in the N-acetyltransferase 2 (NAT2) gene, which is responsible for INH hepatic metabolism, and a risk of DILI in TB patients. In this study, the genetic and baseline clinical data from 366 Japanese patients with TB (73 patients with DILI and 293 without DILI) were used to develop a system to predict DILI risk due to anti-TB agents. The distribution of the NAT2 acetylator status among the TB patients with DILI was 31 (42.5%), 29 (39.7%), and 13 (17.8%) for rapid, intermediate, and slow acetylators, respectively. A significant association was observed between NAT2 slow acetylators and DILI risk (odds ratio 4.32, 95% confidence interval 1.93–9.66, P value=5.56×10−4). A logistic regression model based on age and NAT2 genotype revealed that the area under the curve for the receiver-operating characteristic curve was 0.717. The findings demonstrated that slow NAT2 acetylator status is a significant predictor of the risk of DILI by anti-TB agents, and a personalized anti-TB treatment approach may aid in making treatment decisions and reducing the incidence of DILI. PMID:27340556

  19. Development of a prediction system for anti-tuberculosis drug-induced liver injury in Japanese patients.

    Science.gov (United States)

    Mushiroda, Taisei; Yanai, Hideki; Yoshiyama, Takashi; Sasaki, Yuka; Okumura, Masao; Ogata, Hideo; Tokunaga, Katsushi

    2016-01-01

    Drug-induced liver injury (DILI) is a common adverse drug reaction in patients receiving antituberculosis (anti-TB) treatment. Among the anti-TB agents, isoniazid (INH) is the primary drug that causes hepatotoxicity in TB patients with DILI. Previous reports in several populations have consistently demonstrated an association between polymorphisms in the N-acetyltransferase 2 (NAT2) gene, which is responsible for INH hepatic metabolism, and a risk of DILI in TB patients. In this study, the genetic and baseline clinical data from 366 Japanese patients with TB (73 patients with DILI and 293 without DILI) were used to develop a system to predict DILI risk due to anti-TB agents. The distribution of the NAT2 acetylator status among the TB patients with DILI was 31 (42.5%), 29 (39.7%), and 13 (17.8%) for rapid, intermediate, and slow acetylators, respectively. A significant association was observed between NAT2 slow acetylators and DILI risk (odds ratio 4.32, 95% confidence interval 1.93-9.66, P value=5.56×10(-4)). A logistic regression model based on age and NAT2 genotype revealed that the area under the curve for the receiver-operating characteristic curve was 0.717. The findings demonstrated that slow NAT2 acetylator status is a significant predictor of the risk of DILI by anti-TB agents, and a personalized anti-TB treatment approach may aid in making treatment decisions and reducing the incidence of DILI. PMID:27340556

  20. Chemically amplified cytochrome P450-2E1 drug metabolism nanobiosensor for rifampicin anti-tuberculosis drug

    International Nuclear Information System (INIS)

    Fully susceptible tuberculosis (TB) develops secondary drug resistance during therapy due to inappropriate dosing of treatment drugs, inadequate treatment, non-adherence to the prescribed regimen or using low quality medication. Therefore, a fast and reliable method for the determination of a patient's metabolic profile for TB drugs is essential for appropriate dosing of these drugs. A nanobiosensor for the determination of the biotransformation of rifampicin (a TB drug) was developed using ethylene glycol bis(succinic acid N-hydroxysuccinimide ester) (EG)-modified cytochrome P450-2E1 (CYP2E1). The EG-CYP2EI enzyme system was electrodeposited on gold electrodes derivatised with polyvinylpyrrolidone/silver nanoparticles/poly(8-anilino-1-naphthalene sulphonic acid) (PVP-AgNPs/PANSA) nanocomposite. The electrochemical impedance spectroscopy (EIS) and transmission electron microscopy (TEM) analyses of the Au/PVP-AgNPs/PANSA/EG-CYP2E1 nanobiosensor system revealed that PVP-AgNPs/PANSA is a highly electroactive nanocomposite whose morphology and properties were suitable for the immobilisation of CYP2E1. The response profile of the nanobiosensor for rifampicin was studied by cyclic voltammetry (CV), differential voltammetry (DPV) and steady state amperometry under aerobic conditions. The dynamic linear range of the nanobiosensor (0.025 - 14 μM) covers the peak rifampicin serum level value of 0.045 μM

  1. Sovereign Default, Domestic Banks and Financial Institutions

    OpenAIRE

    Gennaioli, Nicola; Martin, Alberto; Rossi, Stefano

    2010-01-01

    We build a model where sovereign defaults weaken banks’ balance sheets because banks hold sovereign bonds, causing private credit to decline. Stronger financial institutions boost default costs by amplifying these balance-sheet effects. This yields a novel complementarity between public debt and domestic credit markets, where the latter sustain the former by increasing the costs of default. We document three novel empirical facts that are consistent with our model's predictions: public defaul...

  2. What HappensAfter a Greek Default

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A Greek default has already occurred in the eyes of investors, even though it technically hasn't happened yet. The market is now forcing European leaders to quickly decide how they want the rest of the sovereign debt crisis to play out. While the technical default of Greece--inevitable as it is--took around 18 months, similar defaults in other peripheral eurozone members will probably come much faster.

  3. Credit default swaps networks and systemic risk

    OpenAIRE

    Michelangelo Puliga; Guido Caldarelli; Stefano Battiston

    2014-01-01

    Credit Default Swaps (CDS) spreads should reflect default risk of the underlying corporate debt. Actually, it has been recognized that CDS spread time series did not anticipate but only followed the increasing risk of default before the financial crisis. In principle, the network of correlations among CDS spread time series could at least display some form of structural change to be used as an early warning of systemic risk. Here we study a set of 176 CDS time series of financial institutions...

  4. Application of Fluorescent Protein Expressing Strains to Evaluation of Anti-Tuberculosis Therapeutic Efficacy In Vitro and In Vivo.

    Science.gov (United States)

    Kong, Ying; Yang, Dong; Cirillo, Suat L G; Li, Shaoji; Akin, Ali; Francis, Kevin P; Maloney, Taylor; Cirillo, Jeffrey D

    2016-01-01

    The slow growth of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), hinders development of new diagnostics, therapeutics and vaccines. Using non-invasive real-time imaging technologies to monitor the disease process in live animals would facilitate TB research in all areas. We developed fluorescent protein (FP) expressing Mycobacterium bovis BCG strains for in vivo imaging, which can be used to track bacterial location, and to quantify bacterial load in live animals. We selected an optimal FP for in vivo imaging, by first cloning six FPs: tdTomato, mCherry, mPlum, mKate, Katushka and mKeima, into mycobacteria under either a mycobacterial Hsp60 or L5 promoter, and compared their fluorescent signals in vitro and in vivo. Fluorescence from each FP-expressing strain was measured with a multimode reader using the optimal excitation and emission wavelengths for the FP. After normalizing bacterial numbers with optical density, the strain expressing L5-tdTomato displayed the highest fluorescence. We used the tdTomato-labeled M. bovis BCG to obtain real-time images of pulmonary infections in living mice and rapidly determined the number of bacteria present. Further comparison between L5-tdTomato and Hsp60-tdTomato revealed that L5-tdTomato carried four-fold more tdTomato gene copies than Hsp60-tdTomato, which eventually led to higher protein expression of tdTomato. Evaluating anti-TB efficacy of rifampicin and isoniazid therapy in vitro and in vivo using the L5-tdTomato strain demonstrated that this strain can be used to identify anti-TB therapeutic efficacy as quickly as 24 h post-treatment. These M. bovis BCG reporter strains represent a valuable new tool for evaluation of therapeutics, vaccines and virulence. PMID:26934495

  5. Application of Fluorescent Protein Expressing Strains to Evaluation of Anti-Tuberculosis Therapeutic Efficacy In Vitro and In Vivo.

    Directory of Open Access Journals (Sweden)

    Ying Kong

    Full Text Available The slow growth of Mycobacterium tuberculosis (Mtb, the causative agent of tuberculosis (TB, hinders development of new diagnostics, therapeutics and vaccines. Using non-invasive real-time imaging technologies to monitor the disease process in live animals would facilitate TB research in all areas. We developed fluorescent protein (FP expressing Mycobacterium bovis BCG strains for in vivo imaging, which can be used to track bacterial location, and to quantify bacterial load in live animals. We selected an optimal FP for in vivo imaging, by first cloning six FPs: tdTomato, mCherry, mPlum, mKate, Katushka and mKeima, into mycobacteria under either a mycobacterial Hsp60 or L5 promoter, and compared their fluorescent signals in vitro and in vivo. Fluorescence from each FP-expressing strain was measured with a multimode reader using the optimal excitation and emission wavelengths for the FP. After normalizing bacterial numbers with optical density, the strain expressing L5-tdTomato displayed the highest fluorescence. We used the tdTomato-labeled M. bovis BCG to obtain real-time images of pulmonary infections in living mice and rapidly determined the number of bacteria present. Further comparison between L5-tdTomato and Hsp60-tdTomato revealed that L5-tdTomato carried four-fold more tdTomato gene copies than Hsp60-tdTomato, which eventually led to higher protein expression of tdTomato. Evaluating anti-TB efficacy of rifampicin and isoniazid therapy in vitro and in vivo using the L5-tdTomato strain demonstrated that this strain can be used to identify anti-TB therapeutic efficacy as quickly as 24 h post-treatment. These M. bovis BCG reporter strains represent a valuable new tool for evaluation of therapeutics, vaccines and virulence.

  6. Novel anti-tuberculosis drug designs by data mining for similarity in substituent substitution and structure modification

    Directory of Open Access Journals (Sweden)

    Ronald Lee Bartzatt

    2011-11-01

    Full Text Available Mycobacterium tuberculosis (TB is among the most common of infectious diseases that cause death, and as many as one-third of the world’s population may be infected. This work presents 17 novel hydrazide agents formed by focused in silico data mining utilizing search parameters restricted to substituent replacement only. Substituent substitution has been highly successful in design of novel antibacterial and antiviral drugs. This diverse set of hydrazide constructs possess molecular properties indicating favorable bioavailability with excellent intestinal absorption for oral administration. All agents have zero violations of the Rule of 5, indicating favorable druglikeness. Important pharmaceutical properties including polar surface area, Log P, and formula weight were determined and compared to that of the parent structure of isoniazid by hierarchical cluster analysis and discriminant analysis. The average Log P with range is -0.258 and -2.165 to 1.373, respectively. The average polar surface area (PSA with range is 75.19 A2 and 55.121 A2 to 94.036 A2, respectively. The diverse range of PSA and Log P, with other descriptors, portend a versatile group of hydrazide drugs having substantial potential to expand the application and effectiveness for clinical treatment of multi-organ infected TB patients. Analysis of similarity indicated that all 17 agents are significantly similar to isoniazid, however discriminant analysis and hierarchical cluster analysis are able to differentiate isoniazid based upon molecular properties. Molecular weight and number of atoms were highly correlated by Pearson r (r > 0.9000, with Log P moderately correlated (r > 0.5500 to number of atoms, molecular weight, and volume. Seventeen hydrazide compounds (success rate of approximately 38% having diverse pharmaceutical properties resulted from substituent data mining with potential for clinical application.

  7. Clinico-pathological profile and treatment outcome in smear negative pulmonary tuberculosis patients at a teaching hospital

    International Nuclear Information System (INIS)

    Tuberculosis remains the single highest contributor to the world's morbidity and mortality. Early diagnosis and prompt treatment is essential to prevent its transmission. To see the treatment response of anti tuberculosis drugs in smear negative patients and study the predictors of culture positive among smear negative tuberculosis patients. Ninety four sputum smear negative patients clinically and radiologically suggestive of tuberculosis were selected. These patients were put on anti tuberculosis drugs without waiting for their culture results. They were then followed for 8 months to see their treatment outcome. A total of 94 smear negative patients were selected and given anti tuberculosis treatment. Of these 37(39%) were culture positive and 57(61%) were culture negative. Of the 37 culture positive patients 36(97%) showed clinical or radiological improvement as compared to 46(81%) out of 57 in culture negative cases. Symptoms of cough with sputum production was significantly associated with culture positivity. On x-ray chest moderate lesion with diffuse infiltration was more common finding in 64% while extensive and cavitatory lesion was seen in 24% of all cases. Association of extensive and cavitatory lesion were seen in culture positive group. Response to anti tuberculosis drugs in sputum smear negative tubercolosis suspects was found to be effective in majority of the patients. Cough, sputum and extensive cavitatory lung lesion were the predictors of culture positive cases. There is need to train physicians on the use of anti tuberculosis therapy in smear negative suspected pulmonary tuberculosis cases, especially if they have productive cough and cavitatory lung lesions. (author)

  8. The epidemic status of drug-resistant tuberculosis and research progress of anti-tuberculosis drugs%耐药结核病流行现状及抗结核药物研究进展

    Institute of Scientific and Technical Information of China (English)

    许寅; 孟现民; 张永信

    2013-01-01

    China is one of the 22 countries with serious tuberculosis epidemic in the whole world and is also one of the 27 countries with the serious multidrug-resistant tuberculosis (MDR-TB). MDR-TB has become the tough problem of public health in many countries. It is an important link to study and develop the new anti-tuberculosis drugs to prevent and control tuberculosis and to improve their efficacy. This article introduces the tuberculosis, especially epidemic status of drug-resistant tuberculosis and research progress of anti-tuberculosis drugs.%  我国是全球22个结核病流行严重的国家之一,同时也是全球27个耐多药结核病流行严重的国家之一。耐多药结核病在许多国家已成为主要公共卫生问题,而研发新型抗结核药物是有效遏制结核病流行和提高结核病防治效果的重要环节之一。本文介绍结核病、尤其是耐多药结核病的流行现状以及抗结核药物研发的最新进展。

  9. Systematic review of clofazimine for the treatment of drug-resistant tuberculosis

    OpenAIRE

    Gopal, M.; Padayatchi, N; Metcalfe, J. Z.; O’Donnell, M. R.

    2013-01-01

    The increased incidence of drug-resistant tuberculosis has created an urgent necessity for the development of new and effective anti-tuberculosis drugs and for alternative therapeutic regimens. Clofazimine (CFZ) is a fat-soluble riminophenazine dye used in the treatment of leprosy worldwide. CFZ has also been used as a Group 5 drug in the treatment of tuberculosis (TB). A large cohort study from Bangladesh published in 2010 described a treatment regimen for multidrug-resistant tuberculosis (M...

  10. Hedging contingent claims on defaultable assets

    Science.gov (United States)

    Beumee, Johan G. B.

    2001-02-01

    Following the JLT model (Jarrow, Lando and Turnbull), this paper represents a defaultable asset as a continuous stochastic process plus a Poisson jump modelling the bankruptcy event. It is shown that if the recovery condition is known beforehand, a contingent claim can be hedged by a position in the defaultable asset and a risk-free instrument. In addition, the claim must satisfy a jump-diffusion equation and a risk-neutral representation is obtained using this equation. Examples include the price of a risky zero-coupon bond with a fixed recovery value and the prices of risky Call/Put options on corporate instruments (instrument terminates upon default).

  11. Defaulters in general practice: reasons for default and patterns of attendance.

    OpenAIRE

    Cosgrove, M P

    1990-01-01

    A series of 40 patients in general practice who failed to attend for their appointments were studied to look at their patterns of attendance over the previous five years, together with their reasons for default. The group not only defaulted more often than a group of age and sex matched controls but made significantly more visits to the surgery. Seventeen of the patients increased their default rate as their attendance rate increased over the five year period. The main reasons patients gave f...

  12. Defaults & Returns on High Yield Bonds: Analysis Through 1998 and Default Outlook for 1999-2001

    OpenAIRE

    Edward I. Altman; Diane Cooke; Vellore Kishore

    1999-01-01

    Nineteen-ninety-eight was a mixed performance year for the high yield bond market in the United States, with much below average returns and spreads over default-risk-free Treasury Bonds but continued relatively low default rates and losses and another record year of new insurance. Returns and new insurance were excellent through the first seven months of the year but returns reversed and new issues dried up, temporarily, in the wake of August's Russians default and the emerging market turmoil...

  13. Adaboost Ensemble Classifiers for Corporate Default Prediction

    Directory of Open Access Journals (Sweden)

    Suresh Ramakrishnan

    2015-01-01

    Full Text Available This study aims to show a substitute technique to corporate default prediction. Data mining techniques have been extensively applied for this task, due to its ability to notice non-linear relationships and show a good performance in presence of noisy information, as it usually happens in corporate default prediction problems. In spite of several progressive methods that have widely been proposed, this area of research is not out dated and still needs further examination. In this study, the performance of multiple classifier systems is assessed in terms of their capability to appropriately classify default and non-default Malaysian firms listed in Bursa Malaysia. Multi-stage combination classifiers provided significant improvements over the single classifiers. In addition, Adaboost shows improvement in performance over the single classifiers.

  14. 10 CFR 820.33 - Default order.

    Science.gov (United States)

    2010-01-01

    ... respondent unless the Director presents sufficient evidence to the Presiding Officer to establish a prima facie case against the respondent. Default by respondent constitutes, for purposes of the pending...

  15. 34 CFR 668.217 - Default prevention plans.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Default prevention plans. 668.217 Section 668.217... Default prevention plans. (a) First year. (1) If your cohort default rate is equal to or greater than 30 percent you must establish a default prevention task force that prepares a plan to— (i) Identify...

  16. Default Recovery Rates and Implied Default Probability Estimations: Evidence from the Argentinean Crisis

    OpenAIRE

    Sosa Navarro, Ramiro

    2005-01-01

    This paper applies the model presented by J. Merrick Jr. (2001) to estimate both the default recovery rates and the im- plied default probabilities of the Argentinean Sovereign Bonds during the crisis which took place in December 2001. Between October 19th and December 24th 2001, the average bond price level reflected a downward trend, falling from USD 56.8 to USD 26.5 for each USD 100 face value. Similarly, default recovery rates descended from USD 38.7 to USD 20.8 whereas the base default p...

  17. Adaboost Ensemble Classifiers for Corporate Default Prediction

    OpenAIRE

    Suresh Ramakrishnan; Maryam Mirzaei; Mahmoud Bekri

    2015-01-01

    This study aims to show a substitute technique to corporate default prediction. Data mining techniques have been extensively applied for this task, due to its ability to notice non-linear relationships and show a good performance in presence of noisy information, as it usually happens in corporate default prediction problems. In spite of several progressive methods that have widely been proposed, this area of research is not out dated and still needs further examination. In this study, the pe...

  18. Country Default Probabilities: Assessing and Backtesting

    OpenAIRE

    Vogl, Konstantin; Maltritz, Dominik; Huschens, Stefan; Karmann, Alexander

    2006-01-01

    We address the problem how to estimate default probabilities for sovereign countries based on market data of traded debt. A structural Merton-type model is applied to a sample of emerging market and transition countries. In this context, only few and heterogeneous default probabilities are derived, which is problematic for backtesting. To deal with this problem, we construct likelihood ratio test statistics and quick backtesting procedures.

  19. Learning Possibilistic Logic Theories from Default Rules

    OpenAIRE

    Kuzelka, Ondrej; Davis, Jesse; SCHOCKAERT, Steven

    2016-01-01

    We introduce a setting for learning possibilistic logic theories from defaults of the form "if alpha then typically beta". We first analyse this problem from the point of view of machine learning theory, determining the VC dimension of possibilistic stratifications as well as the complexity of the associated learning problems, after which we present a heuristic learning algorithm that can easily scale to thousands of defaults. An important property of our approach is that it is inherently abl...

  20. Default Risk and Risk Averse International Investors

    OpenAIRE

    Lizarazo, Sandra

    2010-01-01

    This paper develops a quantitative model of debt and default for small open economies that interact with risk averse international investors. The model developed here extends the recent work on the analysis of endogenous default risk to the case in which international investors are risk averse agents with decreasing absolute risk aversion (DARA). By incorporating risk averse investors who trade with a single emerging economy, the present model o ers two main improvements over the standard cas...

  1. GDP-linked bonds and sovereign default

    OpenAIRE

    Barr, David; Bush, Oliver; Pienkowski, Alex

    2014-01-01

    Using a calibrated model of endogenous sovereign default, we explore how GDP-linked bonds can raise the maximum sustainable debt level of a government, and substantially reduce the incidence of default. The model explores both the costs (in particular the GDP risk premium) and the benefits of issuing GDP-linked bonds. It concludes that significant welfare gains can be achieved by indexing debt to GDP.

  2. BILATERAL COUNTERPARTY RISK VALUATION OF CDS CONTRACTS WITH SIMULTANEOUS DEFAULTS

    OpenAIRE

    LONG TENG; MATTHIAS EHRHARDT; MICHAEL GÜNTHER

    2013-01-01

    We analyze the general risk-neutral valuation for counterparty risk embedded in a Credit Default Swap (CDS) contract by adapting the recent findings of Brigo and Capponi (2009) to allow for simultaneous defaults among the two parties and the underlying reference credit, while the counterparty risk is considered bilaterally. For the default intensities, we employ a Markov copula model allowing for the possibility of a simultaneous default. The dependence between defaults of three names in a CD...

  3. Liquidity, Default and Crashes: Endogenous Contracts in General Equilibrium

    OpenAIRE

    John Geanakoplos

    2001-01-01

    The possibility of default limits available liquidity. If the potential default draws nearer, a liquidity crisis may ensue, causing a crash in asset prices, even if the probability of default barely changes, and even if no defaults subsequently materialize. Introducing default and limited collateral into general equilibrium theory (GE) allows for a theory of endogenous contracts, including endogenous margin requirements on loans. This in turn allows GE to explain liquidity and liquidity crise...

  4. [Analysis on characteristics of ancient acupuncture and moxibustion treatment of tuberculosis consumptive diseases].

    Science.gov (United States)

    Guo, Yao-jie; Gu, Jie; Liu, Li-gong

    2005-02-01

    Systematical and comprehensive statistics, induction and analysis on literature and data of acupuncture and moxibustion treatment of tuberculosis in incunabula are carried out by computer. The results indicate that in treatment of tuberculosis, most select acupoints of the upper back, chest-epigastrium and The Yangming Channel on the leg to promote dispersing function of the lung, strength the spleen and anti-tuberculosis; select acupoints of The Conception Vessel on the lower abdomen and Shenshu (BL 23) and others on the lower back to tonify the kidney and anti-tuberculosis. Clinically, most select moxibustion and acupuncture with reinforcing-reducing manipulation and pricking blood therapy. And referential recipes for clinical treatment are raised. PMID:16312901

  5. Counting Processes for Retail Default Modeling

    DEFF Research Database (Denmark)

    Kiefer, Nicholas Maximilian; Larson, C. Erik

    Counting processes provide a very flexible framework for modeling discrete events occurring over time. Estimation and interpretation is easy, and links to more familiar approaches are at hand. The key is to think of data as "event histories," a record of times of switching between states...... in a discrete state space. In a simple case, the states could be default/non-default; in other models relevant for credit modeling the states could be credit scores or payment status (30 dpd, 60 dpd, etc.). Here we focus on the use of stochastic counting processes for mortgage default modeling, using data...... by these different methods? We address this question in the counting process framework. In fact, MI is associated with lower d...

  6. Education, Health, and the Default American Lifestyle.

    Science.gov (United States)

    Mirowsky, John; Ross, Catherine E

    2015-09-01

    Education has a large and increasing impact on health in America. This paper examines one reason why. Education gives individuals the ability to override the default American lifestyle. The default lifestyle has three elements: displacing human energy with mechanical energy, displacing household food production with industrial food production, and displacing health maintenance with medical dependency. Too little physical activity and too much food produce imperceptibly accumulating pathologies. The medical industry looks for products and services that promise to soften the consequences but do not eliminate the underlying pathologies. This "secondary prevention" creates pharmacologic accumulation: prolonging the use of medications, layering them, and accruing their side effects and interactions. Staying healthy depends on recognizing the risks of the default lifestyle. Overriding it requires insight, knowledge, critical analysis, long-range strategic thinking, personal agency, and self-direction. Education develops that ability directly and indirectly, by way of creative work and a sense of controlling one's own life. PMID:26272989

  7. Characterization of an Auto-Compatible Default Theory

    Institute of Scientific and Technical Information of China (English)

    XU DaoYun(许道云); DING DeCheng(丁德成); ZHANG MingYi(张明义)

    2003-01-01

    In this paper, an equivalence condition for deciding whether a default theory isan auto-compatible default one is presented. Under the condition, the existence of extension of anauto-compatible default theory is a natural result. By introducing a well-ordering over the set D ofdefault rules, the extensions of an auto-compatible default theory (D, W) can be computed directly.The condition represents clearly the characterization of an auto-compatible default theory, andsome properties about auto-compatible default theory, such as semi-monotonicity, become naturalcorollaries. Based on the characterization, the revision of default beliefs is discussed to ensure theexistence of extension of the default theory, and the method is applied to investigate stable modelsof a general logic program.

  8. Moody's Correlated Binomial Default Distributions for Inhomogeneous Portfolios

    CERN Document Server

    Mori, S; Kitsukawa, K

    2006-01-01

    This paper generalizes Moody's correlated binomial default distribution for homogeneous credit portfolio, which is introduced by Witt, to the case of inhomogeneous portfolios. As inhomogeneous portfolios, we consider two cases. In the first case, we treat a portfolio whose assets have uniform default correlation and non-uniform default probabilities. We obtain the default probability distribution and study the effect of the inhomogeneity on it. The second case corresponds to a portfolio with inhomogeneous default correlation. Assets are categorized in several different sectors and the inter-sector and intra-sector correlations are not the same. We construct the joint default probabilities and obtain the default probability distribution. We show that as the number of assets in each sector decreases, inter-sector correlation becomes more important than the intra-sector one. We study the maximum values of the inter-sector default correlation. In the modeling of portfolio credit risk, it is possible to incorporat...

  9. 31 CFR 501.716 - Default.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Default. 501.716 Section 501.716 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... determine the proceeding against that party upon consideration of the record if that party fails: (1)...

  10. Collective strategic defaults: Bailouts and repayment incentives

    NARCIS (Netherlands)

    R. Vlahu

    2008-01-01

    This paper shows that under a global games approach banks may be subject to risk of failure even when fundamentals are strong due to a coordination problem among debtors. As a result of collective strategic default a financially sound firm may claim inability to repay if it expects a sufficient numb

  11. Convertible Bonds: Default Risk and Uncertain Volatility

    OpenAIRE

    Huang, Haishi

    2009-01-01

    Within a default intensity approach we discuss the optimal exercise of the callable and convertible bonds. Pricing bounds for convertible bonds are derived in an uncertain volatility model, i.e. when the volatility of the stock price process lies between two extreme values.

  12. 10 CFR 800.304 - Default.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Default. 800.304 Section 800.304 Energy DEPARTMENT OF ENERGY LOANS FOR BID OR PROPOSAL PREPARATION BY MINORITY BUSINESS ENTERPRISES SEEKING DOE CONTRACTS AND... section, and no deferral or restructuring is agreed to by the Secretary as provided in paragraph (d)...

  13. Whose Fault is Student Loan Default?

    Science.gov (United States)

    Jenkins, John A.

    1978-01-01

    Student loan programs have been racked by defaults, bankruptcies, and administrative trivia, causing Congress to search for another system. Under consideration is a loan that would be repaid to the Internal Revenue Service through a withholding tax. However, better collection efforts with the present system are producing encouraging results. (JMD)

  14. Determinants of automobile loan default and prepayment

    OpenAIRE

    Sumit Agarwal; Ambrose, Brent W.; Souphala Chomsisengphet

    2008-01-01

    The authors examine whether a borrower’s choice of automobile reveals information about future loan performance. They find that loans on most luxury automobiles have a higher probability of prepayment, while loans on most economy automobiles have a lower probability of default, even when holding traditional risk factors, such as income and credit score, constant.

  15. Sovereign Defaulters: Do International Capital Markets Punish Them?

    OpenAIRE

    Miguel Fuentes; Diego Saravia

    2006-01-01

    We study empirically if countries that default on their debt experience a reduction in their capital inflows as suggested by the literature. Our data contains information on (i) the defaulter countries and their creditors and (ii) bilateral foreign direct investment (FDI) flows. With this we can study how FDI flows are affected by sovereign default distinguishing among those coming from defaulters' creditor countries and others. According to our estimations, this distinction is crucial since ...

  16. Modeling Banks¡¯ Probability of Default

    OpenAIRE

    2015-01-01

    The unprecedented financial crisis of 2008-2009 has called attention to limitations of existing methods for estimating the default risk of financial intuitions. Over the past decade, we have had considerable success at predicting default and credit relative value using Merton-type structural models and Hybrid Probability of Default models. However, generating accurate model-based estimates of default probabilities (PDs) for financial firms has proven difficult. To address this need, I built a...

  17. The Credit Default Swap Market and the Settlement of Large Defaults

    OpenAIRE

    Virginie Coudert; Mathieu Gex

    2010-01-01

    The huge positions on the credit default swaps (CDS) have raised concerns about the ability of the market to settle major entities’ defaults. The near-failure of AIG and the bankruptcy of Lehman Brothers in 2008 have revealed the exposure of CDS’s buyers to counterparty risk and hence highlighted the necessity of organizing the market, which triggered a large reform process. First we analyse the vulnerabilities of the market at the bursting of this crisis. Second, to understand its resilience...

  18. Systematic and Idiosyncratic Default Risk in Synthetic Credit Markets

    DEFF Research Database (Denmark)

    Feldhütter, Peter; Nielsen, Mads Stenbo

    2012-01-01

    We present a new estimation approach that allows us to extract from spreads in synthetic credit markets the contribution of systematic and idiosyncratic default risk to total default risk. Using an extensive dataset of 90,600 credit default swap and collateralized debt obligation (CDO) tranche...

  19. Fixed-Parameter Tractability of Disjunction-Free Default Reasoning

    Institute of Scientific and Technical Information of China (English)

    ZHAO XiShun(赵希顺); DING DeCheng(丁德成)

    2003-01-01

    In this paper, the parameter which is the source of the complexity of disjunctionfree default reasoning is determined. It is shown that when the value of this parameter is fixed, the disjunction-free default reasoning can be solved in time bounded by a polynomial whose degree does not depend on the parameter. Consequently, disjunction-free default reasoning is fixed parameter tractable.

  20. 14 CFR 17.37 - Default adjudicative process for protests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Default adjudicative process for protests... TRANSPORTATION PROCEDURAL RULES PROCEDURES FOR PROTESTS AND CONTRACTS DISPUTES Default Adjudicative Process § 17.37 Default adjudicative process for protests. (a) Other than for the resolution of preliminary...

  1. Vitamin D as Supplementary Treatment for Tuberculosis

    DEFF Research Database (Denmark)

    Wejse, Christian; Gomes, Victor F; Rabna, Paulo;

    2009-01-01

    RATIONALE: Vitamin D has been shown to be involved in host immune response towards M. tuberculosis. OBJECTIVE: To test whether vitamin D supplementation of TB patients improved clinical outcome and reduced mortality. METHODS: We conducted a randomized double-blind placebo-controlled trial in TB...... clinics at a Demographic Surveillance Site in Guinea Bissau. We included 365 adult TB patients starting anti-tuberculosis treatment, 281 completed 12 month follow-up. The intervention was 100,000 IU cholecalciferol or placebo at inclusion and again at 5 and 8 months after start of treatment. Measurements...

  2. Modelling credit risk with scarce default data: on the suitability of cooperative bootstrapped strategies for small low-default portfolios

    OpenAIRE

    Raquel Florez-Lopez; Juan Manuel Ramon-Jeronimo

    2014-01-01

    Credit risk models are commonly based on large internal data sets to produce reliable estimates of the probability of default (PD) that should be validated with time. However, in the real world, a substantial portion of the exposures is included in low-default portfolios (LDPs) in which the number of defaulted loans is usually much lower than the number of non-default observations. Modelling of these imbalanced data sets is particularly problematic with small portfolios in which the absence o...

  3. Impact of Physician's Education on Adherence to Tuberculosis Treatment for Patients of Low Socioeconomic Status in Bangladesh

    OpenAIRE

    Lee, Shinwon; Khan, Omar Faruk; Seo, Jeong Ho; Kim, Dong Yeon; Park, Kyung-Hwa; Jung, Sook-In; Chung, Eun-Kyung; Jang, Hee-Chang

    2013-01-01

    Successful tuberculosis control depends on good adherence to treatment. Yet, limited data are available on the efficacy of methods for improving the adherence of patients of low socioeconomic status. We evaluated the impact of physician-provided patient education on adherence to anti-tuberculosis medication in a low socioeconomic status and resource-limited setting. A pre-/post-intervention study was conducted at a suburban primary health care clinic in Bangladesh where an intensive education...

  4. Time-kill kinetics of anti-tuberculosis drugs, and emergence of resistance, in relation to metabolic activity of Mycobacterium tuberculosis.

    NARCIS (Netherlands)

    Steenwinkel, J.E. de; Knegt, G.J. de; Kate, M.T. Ten; Belkum, A. van; Verbrugh, H.A.; Kremer, K.; Soolingen, D. van; Bakker-Woudenberg, I.A.

    2010-01-01

    OBJECTIVES: The pharmacodynamics of tuberculosis (TB) treatment should be further explored, to prevent emergence of resistance, treatment failure and relapse of infection. The diagnostic drug susceptibility tests guiding TB therapy investigate metabolically active Mycobacterium tuberculosis (Mtb) is

  5. Nudge for (the Public Good: How Defaults Can Affect Cooperation.

    Directory of Open Access Journals (Sweden)

    Toke R Fosgaard

    Full Text Available In this paper we test the effect of non-binding defaults on the level of contribution to a public good. We manipulate the default numbers appearing on the decision screen to nudge subjects toward a free-rider strategy or a perfect conditional cooperator strategy. Our results show that the vast majority of our subjects did not adopt the default numbers, but their stated strategy was affected by the default. Moreover, we find that our manipulation spilled over to a subsequent repeated public goods game where default was not manipulated. Here we found that subjects who previously saw the free rider default were significantly less cooperative than those who saw the perfect conditional cooperator default.

  6. Nudge for (the Public) Good: How Defaults Can Affect Cooperation.

    Science.gov (United States)

    Fosgaard, Toke R; Piovesan, Marco

    2015-01-01

    In this paper we test the effect of non-binding defaults on the level of contribution to a public good. We manipulate the default numbers appearing on the decision screen to nudge subjects toward a free-rider strategy or a perfect conditional cooperator strategy. Our results show that the vast majority of our subjects did not adopt the default numbers, but their stated strategy was affected by the default. Moreover, we find that our manipulation spilled over to a subsequent repeated public goods game where default was not manipulated. Here we found that subjects who previously saw the free rider default were significantly less cooperative than those who saw the perfect conditional cooperator default. PMID:26717569

  7. Recalculating default values for palm oil

    OpenAIRE

    Pehnelt, Gernot; Vietze, Christoph

    2011-01-01

    On 05 December 2010, the Renewable Energy Directive (RED) came into force in the EU. Member States are still working to fully transpose the Directive into national law and establish a framework for achieving their legally binding greenhouse gas (GHG) emission reductions. However, governments got off to a slow start as debate continues on the validity of the directives foundations including the default values used to measure the sustainability of biofuels. Only sustainable biofuels can be coun...

  8. The Australian Credit Default Swap Markets

    OpenAIRE

    Daniel Fabbro

    2011-01-01

    The Australian credit default swap (CDS) market has been increasingly used by financial institutions to trade and manage credit risk. As a result, there has been greater use of the market as a source of credit risk pricing information. Similarities between CDS and bonds allow pricing in the two markets to be compared. However, the CDS market has a greater tendency at times to be affected by poor liquidity, which complicates the interpretation of CDS pricing, particularly when there are large ...

  9. Credit Default Swaps and Sovereign Debt Markets

    OpenAIRE

    M. Kabir Hassan; Geoffrey M. Ngene; Jung Suk-Yu

    2011-01-01

    This study investigates the link between price discovery dynamics in sovereign credit default swaps (CDS) and bond markets and degree of financial integration of emerging markets. Using CDS and sovereign bond spreads, the price discovery mechanism was tested using a vector error correction model. Financial integration is measured using news-based methods. We find that sovereign CDS and bond markets are cointegrated. In 57 percent of times, the CDS market leads in price discovery by adjusting ...

  10. Advanced Methods for Loss Given Default Estimation

    OpenAIRE

    Töws, Eugen

    2016-01-01

    This thesis consists of three essays on the estimation of the risk parameter LGD. The first essay (Hartmann-Wendels, Miller, and Töws, 2014, Loss given default for leasing: Parametric and nonparametric estimations) fills a gap in LGD related literature by focusing on elementary differences of the examined estimation approaches. We find that finite mixture models are quite capable of reproducing the unusual shape of the LGD distribution. However, out-of-sample the estimation error increases si...

  11. Are all Credit Default Swap databases equal?

    OpenAIRE

    Schwartz, Eduardo S.; Peña Sánchez de Rivera, Juan Ignacio; Mayordomo, Sergio

    2010-01-01

    The presence of different prices in different databases for the same securities can impair the comparability of research efforts and seriously damage the management decisions based upon such research. In this study we compare the six major sources of corporate Credit Default Swap prices: GFI, Fenics, Reuters EOD, CMA, Markit and JP Morgan, using the most liquid single name 5-year CDS of the components of the leading market indexes, iTraxx (European firms) and CDX (US firms) for the period fro...

  12. Internalizing Technological Externality under Default Risk

    OpenAIRE

    Futamura, Hiroshi

    2007-01-01

    In this short article, we investigate the effects of public policies on the market equilibrium resource allocation in an economy that is affected by two sources of market failure; (i) positive technological externalities, and (ii) indebted firms' incentive to default. The Priority Production System employed by the Japanese government during the reconstruction period after World War II could achieve the first-best outcome in such an environment.

  13. Default contagion risks in Russian interbank market

    OpenAIRE

    Leonidov, A. V.; E. L. Rumyantsev

    2014-01-01

    Systemic risks of default contagion in the Russian interbank market are investigated. The analysis is based on considering the bow-tie structure of the weighted oriented graph describing the structure of the interbank loans. A probabilistic model of interbank contagion explicitly taking into account the empirical bow-tie structure reflecting functionality of the corresponding nodes (borrowers, lenders, borrowers and lenders simultaneously), degree distributions and disassortativity of the int...

  14. Loss Given Default Modelling: Comparative Analysis

    OpenAIRE

    Yashkir, Olga; Yashkir, Yuriy

    2013-01-01

    In this study we investigated several most popular Loss Given Default (LGD) models (LSM, Tobit, Three-Tiered Tobit, Beta Regression, Inflated Beta Regression, Censored Gamma Regression) in order to compare their performance. We show that for a given input data set, the quality of the model calibration depends mainly on the proper choice (and availability) of explanatory variables (model factors), but not on the fitting model. Model factors were chosen based on the amplitude of their correlati...

  15. Credit Default Swaps networks and systemic risk

    Science.gov (United States)

    Puliga, Michelangelo; Caldarelli, Guido; Battiston, Stefano

    2014-11-01

    Credit Default Swaps (CDS) spreads should reflect default risk of the underlying corporate debt. Actually, it has been recognized that CDS spread time series did not anticipate but only followed the increasing risk of default before the financial crisis. In principle, the network of correlations among CDS spread time series could at least display some form of structural change to be used as an early warning of systemic risk. Here we study a set of 176 CDS time series of financial institutions from 2002 to 2011. Networks are constructed in various ways, some of which display structural change at the onset of the credit crisis of 2008, but never before. By taking these networks as a proxy of interdependencies among financial institutions, we run stress-test based on Group DebtRank. Systemic risk before 2008 increases only when incorporating a macroeconomic indicator reflecting the potential losses of financial assets associated with house prices in the US. This approach indicates a promising way to detect systemic instabilities.

  16. Understanding Emerging Market Sovereign Bond Yield Spread: Role of Default and Non-Default Determinants

    Directory of Open Access Journals (Sweden)

    Adelia Surya Pratiwi

    2015-01-01

    Full Text Available This paper is motivated by the fact that emerging market assets size has been expanding and trying to use sovereign debt market as part of capital market as main research focus. It is highlighting the distinction between default and non-default determinants and examining their significance in explaining emerging market sovereign bond yield spread. Using Cross-Sectional Fixed-Effect Panel Estimator, we found that both default (as proxied by Credit Rating and Outlook Index and non-default (as proxied by 3-month Fed Funds Futures determinants has significant explanatory power to sovereign bond yield spread. Extensively, we also found the significance to add volatility of 3-month Fed Funds Futures and Fed Target Rate basis and volatility of advanced stock markets as variables to stand for non-default determinants in the model. The significance of the latter model is strengthened by higher forecasting as well as indicates the significant role of US market to emerging market sovereign bond market.

  17. Auto Default Gateway Settings for Virtual Machines in Servers using Default Gateway Weight Settings Protocol (DGW

    Directory of Open Access Journals (Sweden)

    Suman Dutta

    2014-11-01

    Full Text Available Availability is one of the most important concerns in the networking world. For any high available network, we need to maintain 99.99999% availability . That is why it is one of the most important facto rs to find out the single point of failure in the network architecture and eliminate that single point of fa ilure (SPOF from physical network and logical network. S POF in our server infrastructure has been analysed in terms of communicating with the router for forwa rding traffic with multiple routers. We have develo ped an algorithm that will automatically select default gateway into the network interface card of virtual machines. The proposed algorithm will automatically enable Default Gateway Weight settings (DGW protocol among routers by configuring Network inter face card with default gateway of all routers. The proposed protocol works based on weight settings fo r the multiple default gateway configuration in the host. There will be heartbeat communication and re- convergence will be performed within the shortest possible time. Lowest weight setting will select th e path for packet forwarding through specified rout ers related with the default gateway from the virtual m achine

  18. Conceptual and Statistical Issues Regarding the Probability of Default and Modeling Default Risk

    Directory of Open Access Journals (Sweden)

    Emilia TITAN

    2011-03-01

    Full Text Available In today’s rapidly evolving financial markets, risk management offers different techniques in order to implement an efficient system against market risk. Probability of default (PD is an essential part of business intelligence and customer relation management systems in the financial institutions. Recent studies indicates that underestimating this important component, and also the loss given default (LGD, might threaten the stability and smooth running of the financial markets. From the perspective of risk management, the result of predictive accuracy of the estimated probability of default is more valuable than the standard binary classification: credible or non credible clients. The Basle II Accord recognizes the methods of reducing credit risk and also PD and LGD as important components of advanced Internal Rating Based (IRB approach.

  19. Indifference of Defaultable Bonds with Stochastic Intensity models

    OpenAIRE

    Regis Houssou; Olivier Besson

    2010-01-01

    The utility-based pricing of defaultable bonds in the case of stochastic intensity models of default risk is discussed. The Hamilton-Jacobi- Bellman (HJB) equations for the value functions is derived. A finite difference method is used to solve this problem. The yield-spreads for both buyer and seller are extracted. The behaviour of the spread curve given the default intensity is analyzed. Finally the impacts of the risk aversion and the correlation coefficient are discussed.

  20. The Role of Demand Response in Default Service Pricing

    International Nuclear Information System (INIS)

    In designing default service for competitive retail markets, demand response has been an afterthought at best. But that may be changing, as states that initiated customer choice in the past five to seven years reach an important juncture in retail market design and consider an RTP-type default service for large commercial and industrial customers. The authors describe the experience to date with RTP as a default service, focusing on its role as an instrument for cultivating price-responsive demand. (author)

  1. Residential Mortgage Default and Consumer Bankruptcy: Theory and Empirical Evidence

    OpenAIRE

    Michelle White; Wenli Li

    2011-01-01

    In this paper we develop a theory where homeowners make joint decisions in financial distress as whether to file for bankruptcy or default on their mortgages. The theory models explicitly institutional details, the federal bankruptcy law and the state foreclosure laws, that govern the two default events separately and their interactions. In particular, we derive regions (defined by households asset, liability, and income positions) where homeowners default on both loans, on one of them, and o...

  2. Default logic as a formalism for understanding commonsense reasoning

    OpenAIRE

    Amati, Gianni; Carlucci Aiello, Luigia; Pirri, Fiora

    1996-01-01

    Commonsense reasoning is the reasoning of agents interacting with the real world. Non monotonic reasoning is a well developed research area gathering the logical formalisms that treat commonsense reasoning. One of the best known of such formalisms is Default logic. In this paper we discuss Default logic at both the proof-theoretic and semantics levels and show that Default logic provides a clear and formal framework to understand the logical nature of commonsense reasoning.

  3. Towards Solving the Multiple Extension Problem: Combining Defaults and Probabilities

    OpenAIRE

    Neufeld, Eric; Poole, David L.

    2013-01-01

    The multiple extension problem arises frequently in diagnostic and default inference. That is, we can often use any of a number of sets of defaults or possible hypotheses to explain observations or make Predictions. In default inference, some extensions seem to be simply wrong and we use qualitative techniques to weed out the unwanted ones. In the area of diagnosis, however, the multiple explanations may all seem reasonable, however improbable. Choosing among them is a matter of quantitative ...

  4. Default in a General Equilibrium Model with Incomplete Markets

    OpenAIRE

    Pradeep Dubey; John Geanakoplos; Martin Shubik

    2000-01-01

    We extend the standard model of general equilibrium with incomplete markets (GEI) to allow for default. The equilibrating variables include aggregate default levels, as well as prices of assets and commodities. Default can be either strategic, or due to ill-fortune. It can be caused by events directly affecting the borrower, or indirectly as part of a chain reaction in which a borrower cannot repay because he himself has not been repaid. Each asset is defined by its promises A, the penalties ...

  5. Incorporating the Dynamics of Leverage into Default Prediction

    OpenAIRE

    Löffler, Gunter; Maurer, Alina

    2009-01-01

    A firm's current leverage ratio is one of the core characteristics of credit quality used in statistical default prediction models. Based on the capital structure literature, which shows that leverage is mean-reverting to a target leverage, we forecast future leverage ratios and include them in the set of default risk drivers. The analysis is done with a discrete duration model. Out-of-sample analysis of default events two to five years ahead reveals that the discriminating power of the durat...

  6. Default contagion risks in Russian interbank market

    Science.gov (United States)

    Leonidov, A. V.; Rumyantsev, E. L.

    2016-06-01

    Systemic risks of default contagion in the Russian interbank market are investigated. The analysis is based on considering the bow-tie structure of the weighted oriented graph describing the structure of the interbank loans. A probabilistic model of interbank contagion explicitly taking into account the empirical bow-tie structure reflecting functionality of the corresponding nodes (borrowers, lenders, borrowers and lenders simultaneously), degree distributions and disassortativity of the interbank network under consideration based on empirical data is developed. The characteristics of contagion-related systemic risk calculated with this model are shown to be in agreement with those of explicit stress tests.

  7. Nudge for (the Public) Good: How Defaults Can Affect Cooperation

    OpenAIRE

    Fosgaard, Toke R.; Marco Piovesan

    2015-01-01

    In this paper we test the effect of non-binding defaults on the level of contribution to a public good. We manipulate the default numbers appearing on the decision screen to nudge subjects toward a free-rider strategy or a perfect conditional cooperator strategy. Our results show that the vast majority of our subjects did not adopt the default numbers, but their stated strategy was affected by the default. Moreover, we find that our manipulation spilled over to a subsequent repeated public go...

  8. Default supply issues divides consumer advocates

    International Nuclear Information System (INIS)

    In Toronto, various agencies, all claiming to represent the best interests of consumers, have taken very different positions on the limits that should be placed on suppliers of standard electricity service, due to an unexpected effect of Ontario's market design. The debate has polarized into either support for the Market Design Committee's recommendations restricting local companies' distribution of electricity to one of passing on the spot market price to their standard customers or the view that municipal utilities should be permitted to enter into contracts for power in order to supply the needs of their standard service customers. The Independent Power Producers' Society of Ontario (IPPSO) takes the position that its member companies should have direct access to the default supply market and not to be forced to deal solely with the spot market to reach this market sector. This default market is expected to be the largest potential end use market in Ontario for the power produced and/or sold by IPPSO members. It is expected to be 70% of the total Ontario wholesale electricity market for many years to come

  9. Association of the CYP2B6 gene with anti-tuberculosis drug-induced hepatotoxicity in a Brazilian Amazon population

    OpenAIRE

    Débora Christina Ricardo Oliveira Fernandes; Ney Pereira Carneiro Santos; Milene Raiol Moraes; Ana Cristina Oliveira Braga; Cleonardo Augusto Silva; Andrea Ribeiro-dos-Santos; Sidney Santos

    2015-01-01

    Objectives: The treatment of tuberculosis (TB) remains a challenge owing to the high incidence of drug-induced hepatotoxicity. The aim of this study was to examine the effect of two gene polymorphisms, one in the CYP2B6 (rs3745274) gene and one in the CYP3A5 (rs776746) gene, on the development of hepatotoxicity in patients treated with anti-TB drugs in a Brazilian Amazon population. Methods: TB patients who were treated with anti-TB drugs were examined for hepatotoxicity, an adverse effect...

  10. Pediatric tuberculous meningitis: Model-based approach to determining optimal doses of the anti-tuberculosis drugs rifampin and levofloxacin for children.

    Science.gov (United States)

    Savic, R M; Ruslami, R; Hibma, J E; Hesseling, A; Ramachandran, G; Ganiem, A R; Swaminathan, S; McIlleron, H; Gupta, A; Thakur, K; van Crevel, R; Aarnoutse, R; Dooley, K E

    2015-12-01

    Pediatric tuberculous meningitis (TBM) is a highly morbid, often fatal disease. Standard treatment includes isoniazid, rifampin, pyrazinamide, and ethambutol. Current rifampin dosing achieves low cerebrospinal fluid (CSF) concentrations, and CSF penetration of ethambutol is poor. In adult trials, higher-dose rifampin and/or a fluoroquinolone reduced mortality and disability. To estimate optimal dosing of rifampin and levofloxacin for children, we compiled plasma and CSF pharmacokinetic (PK) and outcomes data from adult TBM trials plus plasma PK data from children. A population PK/pharmacodynamic (PD) model using adult data defined rifampin target exposures (plasma area under the curve (AUC)0-24 = 92 mg*h/L). Levofloxacin targets and rifampin pediatric drug disposition information were literature-derived. To attain target rifampin exposures, children require daily doses of at least 30 mg/kg orally or 15 mg/kg intravenously (i.v.). From our pediatric population PK model, oral levofloxacin doses needed to attain exposure targets were 19-33 mg/kg. Our results provide data-driven guidance to maximize pediatric TBM treatment while we await definitive trial results. PMID:26260983

  11. President Hails Continued Decline in Default Rate on Student Loans.

    Science.gov (United States)

    Burd, Stephen

    1997-01-01

    President Bill Clinton used the declining default rate on college student loans as a basis for proposing tax breaks for college costs. Reduced defaults have saved taxpayer money and helped reduce the federal deficit. Over 150 colleges and universities, including 25 private institutions, risk losing eligibility for federal grant and loan programs…

  12. Translation Compensation for Cultural Default in Lexical Level

    Institute of Scientific and Technical Information of China (English)

    杨瑞锋

    2015-01-01

    Cultural default is a concept derived from the cultural comparison between different cultures. People sharing the same culture do not realize its existence;however it often gives rise to obstacles for translators. By means of case studies, this paper dis⁃cusses the translation compensation for cultural default in lexical level.

  13. 47 CFR 64.1703 - Dispute resolution default process.

    Science.gov (United States)

    2010-10-01

    ... NASDO, the comments and any alternative text provided by the funding party seeking dispute resolution... 47 Telecommunication 3 2010-10-01 2010-10-01 false Dispute resolution default process. 64.1703... Communications Act: Dispute Resolution Regarding Equipment Standards § 64.1703 Dispute resolution default...

  14. 24 CFR 203.333 - Reinstatement of defaulted mortgage.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Reinstatement of defaulted mortgage... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES SINGLE FAMILY MORTGAGE INSURANCE Contract Rights and Obligations Default Under Mortgage §...

  15. 46 CFR 502.605 - Payment of penalty: Method; default.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Payment of penalty: Method; default. 502.605 Section 502... Payment of penalty: Method; default. (a) Method. Payment of penalties by the respondent is to be made by... instruments submitted in payment of claims shall be made payable to the Federal Maritime Commission....

  16. Default Reasoning and Belief Revision: A Syntax-Independent Approach

    Institute of Scientific and Technical Information of China (English)

    张东摩; 朱朝晖; 陈世福

    2000-01-01

    As an important variant of Reiter's default logic, Poole (1988) de veloped a nonmonotonic reasoning framework in the classical first-order language. Brewka and Nebel extended Poole's approach in order to enable a representation of priorities between defaults. In this paper a general framework for default reasoning is presented, which can be viewed as a generalization of the three approaches above. It is proved that the syntax-independent default reasoning in this framework is iden tical to the general belief revision operation introduced by Zhang et al. (1997). This result provides a solution to the problem whether there is a correspondence between belief revision and default logic for the infinite case. As a by-product, an answer to the question, raised by Mankinson and Gairdenfors (1991), is also given about whether there is a counterpart contraction in nonmonotonic logic.

  17. Hepatitis C virus co-infection increases the risk of anti-tuberculosis drug-induced hepatotoxicity among patients with pulmonary tuberculosis.

    Directory of Open Access Journals (Sweden)

    Nino Lomtadze

    Full Text Available BACKGROUND: The country of Georgia has a high prevalence of tuberculosis (TB and hepatitis C virus (HCV infection. PURPOSE: To determine whether HCV co-infection increases the risk of incident drug-induced hepatitis among patients on first-line anti-TB drug therapy. METHODS: Prospective cohort study; HCV serology was obtained on all study subjects at the time of TB diagnosis; hepatic enzyme tests (serum alanine aminotransferase [ALT] activity were obtained at baseline and monthly during treatment. RESULTS: Among 326 study patients with culture-confirmed TB, 68 (21% were HCV co-infected, 14 (4.3% had chronic hepatitis B virus (HBV infection (hepatitis B virus surface antigen positive [HBsAg+], and 6 (1.8% were HIV co-infected. Overall, 19% of TB patients developed mild to moderate incident hepatotoxicity. In multi-variable analysis, HCV co-infection (adjusted Hazards Ratio [aHR]=3.2, 95% CI=1.6-6.5 was found to be an independent risk factor for incident anti-TB drug-induced hepatotoxicity. Survival analysis showed that HCV co-infected patients developed hepatitis more quickly compared to HCV seronegative patients with TB. CONCLUSION: A high prevalence of HCV co-infection was found among patients with TB in Georgia. Drug-induced hepatotoxicity was significantly associated with HCV co-infection but severe drug-induced hepatotoxicity (WHO grade III or IV was rare.

  18. Using default inheritance to describe LTAG

    CERN Document Server

    Evans, R; Weir, D; Evans, Roger; Gazdar, Gerald; Weir, David

    1995-01-01

    We present the results of an investigation into how the set of elementary trees of a Lexicalized Tree Adjoining Grammar can be represented in the lexical knowledge representation language DATR (Evans & Gazdar 1989a,b). The LTAG under consideration is based on the one described in Abeille et al. (1990). Our approach is similar to that of Vijay-Shanker & Schabes (1992) in that we formulate an inheritance hierarchy that efficiently encodes the elementary trees. However, rather than creating a new representation formalism for this task, we employ techniques of established utility in other lexically-oriented frameworks. In particular, we show how DATR's default mechanism can be used to eliminate the need for a non-immediate dominance relation in the descriptions of the surface LTAG entries. This allows us to embed the tree structures in the feature theory in a manner reminiscent of HPSG subcategorisation frames, and hence express lexical rules as relations over feature structures.

  19. Sovereign Default Analysis through Extreme Events Identification

    Directory of Open Access Journals (Sweden)

    Vasile George MARICA

    2015-06-01

    Full Text Available This paper investigates contagion in international credit markets through the use of a novel jump detection technique proposed by Chan and Maheuin (2002. This econometrical methodology is preferred because it is non-linear by definition and not a subject to volatility bias. Also, the identified jumps in CDS premiums are considered as outliers positioned beyond any stochastic movement that can and is already modelled through well-known linear analysis. Though contagion is hard to define, we show that extreme discrete movements in default probabilities inferred from CDS premiums can lead to sound economic conclusions about the risk profile of sovereign nations in international bond markets. We find evidence of investor sentiment clustering for countries with unstable political regimes or that are engaged in armed conflict. Countries that have in their recent history faced currency or financial crises are less vulnerable to external unexpected shocks. First we present a brief history of sovereign defaults with an emphasis on their increased frequency and geographical reach, as financial markets become more and more integrated. We then pass to a literature review of the most important definitions for contagion, and discuss what quantitative methods are available to detect the presence of contagion. The paper continues with the details for the methodology of jump detection through non-linear modelling and its use in the field of contagion identification. In the last sections we present the estimation results for simultaneous jumps between emerging markets CDS and draw conclusions on the difference of behavior in times of extreme movement versus tranquil periods.

  20. Default risk modeling with position-dependent killing

    Science.gov (United States)

    Katz, Yuri A.

    2013-04-01

    Diffusion in a linear potential in the presence of position-dependent killing is used to mimic a default process. Different assumptions regarding transport coefficients, initial conditions, and elasticity of the killing measure lead to diverse models of bankruptcy. One “stylized fact” is fundamental for our consideration: empirically default is a rather rare event, especially in the investment grade categories of credit ratings. Hence, the action of killing may be considered as a small parameter. In a number of special cases we derive closed-form expressions for the entire term structure of the cumulative probability of default, its hazard rate, and intensity. Comparison with historical data on aggregate global corporate defaults confirms the validity of the perturbation method for estimations of long-term probability of default for companies with high credit quality. On a single company level, we implement the derived formulas to estimate the one-year likelihood of default of Enron on a daily basis from August 2000 to August 2001, three months before its default, and compare the obtained results with forecasts of traditional structural models.

  1. Valuation of Sovereign Debt with Strategic Defaulting and Rescheduling

    OpenAIRE

    Michael WESTPHALEN

    2002-01-01

    This paper provides a simple model of the rescheduling of debt following a sovereign default as a bond exchange. In case of default, the sovereign offers a new bond with lower coupon and principal.The debtors accept the offer if the value of the new bonds is higher than the proceedings of the litigation of the sovereign. Both the default decision of the sovereign as well as the exchange offer are modeled endogenously and in closed form. The resulting formulas for bond value and credit spreads...

  2. Macro-economy in models for default probability.

    OpenAIRE

    Geurdes, Han / J. F.

    2011-01-01

    We inspect the question how to adapt to macro-economical variables those probability of default (PD) estimates where Merton's model assumptions cannot be used. The need for this is to obtain trustworthy estimates of PD from a given economical situation. The structure of a known market-credit risk model is adapted. The key concept in this adaptation is the assumption of a different probabilistic situation for a firm before and at (first) default. If a corporate firm defaults we use a differ...

  3. Recovery rates, default probabilities and the credit cycle

    OpenAIRE

    Bruche, M.; Gonzalez-Aguado, C.

    2006-01-01

    Recovery rates are negatively related to default probabilities (Altman et al., 2005). This paper proposes and estimates a model in which this dependence is the result of an unobserved credit cycle: When times are bad, the default probability is high and recovery rates are low; when times are good, the default probability is low and recovery rates are high. The proposed dynamic model is shown to produce a better fit to the data than a standard static approach. It indicates that ignoring the dy...

  4. A Note on Pricing Options on Defaultable Stocks

    CERN Document Server

    Bayraktar, Erhan

    2007-01-01

    In this note, we develop stock option price approximations for a model which takes both the risk o default and the stochastic volatility into account. We also let the intensity of defaults be influenced by the volatility. We show that it might be possible to infer the risk neutral default intensity from the stock option prices. Our option price approximation has a rich implied volatility surface structure and fits the data implied volatility well. Our calibration exercise shows that an effective hazard rate from bonds issued by a company can be used to explain the implied volatility skew of the implied volatility of the option prices issued by the same company.

  5. Local Risk-Minimization for Defaultable Claims with Recovery Process

    International Nuclear Information System (INIS)

    We study the local risk-minimization approach for defaultable claims with random recovery at default time, seen as payment streams on the random interval [0,τ∧T], where T denotes the fixed time-horizon. We find the pseudo-locally risk-minimizing strategy in the case when the agent information takes into account the possibility of a default event (local risk-minimization with G-strategies) and we provide an application in the case of a corporate bond. We also discuss the problem of finding a pseudo-locally risk-minimizing strategy if we suppose the agent obtains her information only by observing the non-defaultable assets.

  6. Local Risk-Minimization for Defaultable Claims with Recovery Process

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, Francesca, E-mail: biagini@mathematik.uni-muenchen.de [LMU, Department of Mathematics (Germany); Cretarola, Alessandra, E-mail: alessandra.cretarola@dmi.unipg.it [Universita degli Studi di Perugia, Dipartimento di Matematica e Informatica (Italy)

    2012-06-15

    We study the local risk-minimization approach for defaultable claims with random recovery at default time, seen as payment streams on the random interval [0,{tau} Logical-And T], where T denotes the fixed time-horizon. We find the pseudo-locally risk-minimizing strategy in the case when the agent information takes into account the possibility of a default event (local risk-minimization with G-strategies) and we provide an application in the case of a corporate bond. We also discuss the problem of finding a pseudo-locally risk-minimizing strategy if we suppose the agent obtains her information only by observing the non-defaultable assets.

  7. 34 CFR Appendix A to Subpart N of... - Sample Default Prevention Plan

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Sample Default Prevention Plan A Appendix A to Subpart... Default Rates Pt. 668, Subpt. N, App. A Appendix A to Subpart N of Part 668—Sample Default Prevention Plan This appendix is provided as a sample plan for those institutions developing a default prevention...

  8. The Role of Demand Response in Default Service Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Barbose, Galen; Goldman, Charles; Neenan, Bernie

    2005-11-09

    Dynamic retail pricing, especially real-time pricing (RTP), has been widely heralded as a panacea for providing much-needed demand response in electricity markets. However, in designing default service for competitive retail markets, demand response has been an afterthought, and in some cases not given any weight at all. But that may be changing, as states that initiated customer choice in the past 5-7 years reach an important juncture in retail market design. Most states with retail choice established an initial transitional period during which utilities were required to offer a default or standard offer generation service, often at a capped or otherwise administratively-determined rate. Many retail choice states have reached the end of their transitional period, and several have adopted or are actively considering an RTP-type default service for large commercial and industrial (C&I) customers. In most cases, the primary reason for adopting RTP as the default service has been to advance policy objectives related to the development of competitive retail markets. However, if attention is paid in its design and implementation, default RTP service can also provide a solid foundation for developing price responsive demand, creating an important link between wholesale and retail market transactions. This article, which draws from a lengthier report, describes experience to date with RTP as a default service, focusing on its role as an instrument for cultivating price responsive demand.1 As of summer 2005, default service RTP was in place or approved for future implementation in five U.S. states: New Jersey, Maryland, Pennsylvania, New York, and Illinois. For each of these states, we conducted a detailed review of the regulatory proceedings leading to adoption of default RTP and interviewed regulatory staff and utilities in these states, as well as eight competitive retail suppliers active in these markets.

  9. Credit Risk, Market Sentiment and Randomly-Timed Default

    OpenAIRE

    Brody, Dorje C.; Hughston, Lane P.; Andrea Macrina

    2010-01-01

    We propose a model for the credit markets in which the random default times of bonds are assumed to be given as functions of one or more independent "market factors". Market participants are assumed to have partial information about each of the market factors, represented by the values of a set of market factor information processes. The market filtration is taken to be generated jointly by the various information processes and by the default indicator processes of the various bonds. The valu...

  10. Sukuk Defaults: On Distress Resolution in Islamic Finance

    OpenAIRE

    van Wijnbergen, Sweder; Zaheer, Sajjad

    2013-01-01

    Islamic strictures require investors to share risks with the entrepreneurs they finance. Sukuk (Islamic securities) come mostly in two varieties, musharakah (basically a joint venture agreement) and ijarah (more like an operational lease agreement). Yet defaults did happen, even in the case of musharakah (joint venture) sukuk discussed in this study. So is Islamic finance failing to deliver on its promises? To answer that question, we analyse four major defaults on Sukuk that have happened re...

  11. Long-Term Contracts Under the Threat of Supplier Default

    OpenAIRE

    Robert Swinney; Serguei Netessine

    2009-01-01

    Contracting with suppliers prone to default is an increasingly common problem in some industries, particularly automotive manufacturing. We model this phenomenon as a two-period contracting game with two identical suppliers, a single buyer, deterministic demand, and uncertain production costs. The suppliers are distressed at the start of the game and do not have access to external sources of capital; hence, revenues from the buyer are crucial in determining whether default occurs. The product...

  12. Determining threshold default risk criterion for trade credit granting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To solve the problem of setting threshold default risk criterion to select retailer eligible for trade credit granting, a novel method of solving simultaneous equations is proposed. This method is based on the bilevel programming modeling of trade credit decisions as an interaction between supplier and retailer. First, the bilevel programming is set up where the supplier decides on credit terms at the top level considering a retailer's default risk, and the retailer determines the order quantity at the lowe...

  13. An analysis of loan default determinants: the Spanish case

    OpenAIRE

    Climent Serrano, Salvador; Pavía Miralles, José Manuel

    2014-01-01

    The Spanish financial system is experiencing a very turbulent economic period in which loan defaults has lived an unprecedented increasing period, going from being less than 1% in 2004 to levels of above 13% in 2013. The impact of this, along with other circumstances, has led to the greatest financial restructuring ever made to date in Spain, with important macroeconomic and microeconomic consequences. This paper studies the determinants of delinquency (loan default) in Spanish credit institu...

  14. An Empirical Analysis of Turkish Credit Default SWAPS

    OpenAIRE

    Hasan BAKLACI; Arslan, İlker

    2006-01-01

    Despite its widespread use globally, majority of the Turkish financial institutions are still unaware of Credit Default Swaps (CDS), stemming mainly from insufficient financial infrastructure and information base for credit derivatives. This study analyzes Turkish CDS from various perspectives. The findings exhibit that 10-year spreads are found to be overpriced, primarily due to the lack of liquidity in current CDS market in Turkey. Besides, the term structure of default probability estimati...

  15. Comparing the effects of defaults in organ donation systems

    OpenAIRE

    van Dalen, H.P.; Henkens, K.

    2014-01-01

    The ability of patients in many parts of the world to benefit from transplantation is limited by growing shortages of transplantable organs. The choice architecture of donation systems is said to play a pivotal role in explaining this gap. In this paper we examine the question how different defaults affect the decision to register as organ donor. Three defaults in organ donation systems are compared: mandated choice, presumed consent and explicit consent. Hypothetical choices from a national ...

  16. Drivers of corporate bankruptcy and default : study concerning Portuguese Companies

    OpenAIRE

    Morais, José Carlos de Matos

    2013-01-01

    My purpose with this dissertation is to investigate the relevance of financial and economic variables as predictors of corporate bankruptcy (default) in Portugal. Understanding the underlying issues behind corporate distress and failure is crucial for several areas particularly: granting (or not) a bank loan, managing credit risk and pricing debt. The present financial and economic crisis stimulated a growing interest on matters related to corporate default, ratings and scoring...

  17. Correlation Structures of Correlated Binomial Models and Implied Default Distribution

    OpenAIRE

    Mori, S.; K. Kitsukawa; M. Hisakado

    2006-01-01

    We show how to analyze and interpret the correlation structures, the conditional expectation values and correlation coefficients of exchangeable Bernoulli random variables. We study implied default distributions for the iTraxx-CJ tranches and some popular probabilistic models, including the Gaussian copula model, Beta binomial distribution model and long-range Ising model. We interpret the differences in their profiles in terms of the correlation structures. The implied default distribution h...

  18. Modelling Bonds & Credit Default Swaps using a Structural Model with Contagion

    OpenAIRE

    Helen Haworth; Christoph Reisinger; William Shaw

    2007-01-01

    This paper develops a two-dimensional structural framework for valuing credit default swaps and corporate bonds in the presence of default contagion. Modelling the values of related firms as correlated geometric Brownian motions with exponential default barriers, analytical formulae are obtained for both credit default swap spreads and corporate bond yields. The credit dependence structure is influenced by both a longer-term correlation structure as well as by the possibility of default conta...

  19. ORIGIN CREDIT-DEFAULT SWAPS, AND IDIOSYNCRATIC THEIR FUNCTIONING

    Directory of Open Access Journals (Sweden)

    Марсель Альбертович Шарипов

    2013-04-01

    Full Text Available Credit-default swaps as well as all derivatives have appeared as a result of policy of a decontrol the American government of bank sector of economy.In article attempt to open motives of unfair use swaps is lead by some states, and modern anti-recessionary decisions concerning derivatives are considered. The objective of research consist it is revealing history and the reasons by occurrence the credit-default swaps, also the history of development the institutional infrastructures for stable and not causing suspicions functioning of the market of credit-default swaps by national regulators.  The research of the given problem in modern aspect of its progress has outstanding of novelty character. The reaction of regulators for the crisis are remarkable which events caused by shadow use of derivative financial tools including and credit-default swaps. In research the authors come to following conclusions. First, credit-default swaps are compatible to qualitative variations in corporate economy and answers to modern calls of more globalized financial system. The second, the functioning of the market of derivatives is really idiosyncratic that predetermines a final adage of that sort that arising problems with derivatives occurs not in their essence, but in purposefulness of their use.DOI: http://dx.doi.org/10.12731/2218-7405-2013-1-40

  20. ORIGIN CREDIT-DEFAULT SWAPS, AND IDIOSYNCRATIC THEIR FUNCTIONING

    Directory of Open Access Journals (Sweden)

    Sharipov Marsel Albertovich

    2013-01-01

    Full Text Available Credit-default swaps as well as all derivatives have appeared as a result of policy of a decontrol the American government of bank sector of economy. In article attempt to open motives of unfair use swaps is lead by some states, and modern anti-recessionary decisions concerning derivatives are considered. The objective of research consist it is revealing history and the reasons by occurrence the credit-default swaps, also the history of development the institutional infrastructures for stable and not causing suspicions functioning of the market of credit-default swaps by national regulators. The research of the given problem in modern aspect of its progress has outstanding of novelty character. The reaction of regulators for the crisis are remarkable which events caused by shadow use of derivative financial tools including and credit-default swaps. In research the authors come to following conclusions. First, credit-default swaps are compatible to qualitative variations in corporate economy and answers to modern calls of more globalized financial system. The second, the functioning of the market of derivatives is really idiosyncratic that predetermines a final adage of that sort that arising problems with derivatives occurs not in their essence, but in purposefulness of their use.

  1. The brain's default network: anatomy, function, and relevance to disease.

    Science.gov (United States)

    Buckner, Randy L; Andrews-Hanna, Jessica R; Schacter, Daniel L

    2008-03-01

    Thirty years of brain imaging research has converged to define the brain's default network-a novel and only recently appreciated brain system that participates in internal modes of cognition. Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment. Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system. Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others. Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems. The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation. The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations. These two subsystems converge on important nodes of integration including the posterior cingulate cortex. The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world. We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease. PMID:18400922

  2. The Two Defaults Scenario for Stressing Credit Portfolio Loss Distributions

    Directory of Open Access Journals (Sweden)

    Dirk Tasche

    2015-12-01

    Full Text Available The impact of a stress scenario of default events on the loss distribution of a credit portfolio can be assessed by determining the loss distribution conditional on these events. While it is conceptually easy to estimate loss distributions conditional on default events by means of Monte Carlo simulation, it becomes impractical for two or more simultaneous defaults as then the conditioning event is extremely rare. We provide an analytical approach to the calculation of the conditional loss distribution for the CreditRisk + portfolio model with independent random loss given default distributions. The analytical solution for this case can be used to check the accuracy of an approximation to the conditional loss distribution whereby the unconditional model is run with stressed input probabilities of default (PDs. It turns out that this approximation is unbiased. Numerical examples, however, suggest that the approximation may be seriously inaccurate but that the inaccuracy leads to overestimation of tail losses and, hence, the approach errs on the conservative side.

  3. A Technical Note on Australian Default Superannuation Investment Strategies

    Directory of Open Access Journals (Sweden)

    Loretta Iskra

    2012-06-01

    Full Text Available Superannuation has become more complex over time. Individual investors are inclined to seek the ‘path of least resistance’ and invest in default investment funds which are typically concentrated in high risk assets. Understanding how these funds will meet the individual needs of members relative to their changing circumstances can provide peace of mind and confidence in the market. Given the value of superannuation as an investment in terms of the economy, it is paramount than an appropriate mechanism be in place for default fund investors. This paper will clarify the existing position relative to default fund investment options and outline future research which will provide the impetus for change in terms ofgovernment policy, the financial planning profession and for industry superannuation funds.

  4. Essays on bankruptcy, mortgage default, and regional migration

    OpenAIRE

    Oswald, F

    2015-01-01

    This thesis is about the role of housing as a consumption good and a risky asset, and how it interacts with other choices like consumption, default, and migration over the lifecycle. In the first chapter the focus is on a quasi natural experiment in the State of Nevada, which abolished deficiency judgments for purchase mortgage loans made after October 2009. We test the effect of the law change on mortgage supply and demand, as well as on mortgage default. We find strong evidence that lenders...

  5. 7 CFR 1717.653 - Borrowers in default.

    Science.gov (United States)

    2010-01-01

    ... AGRICULTURE POST-LOAN POLICIES AND PROCEDURES COMMON TO INSURED AND GUARANTEED ELECTRIC LOANS Investments, Loans, and Guarantees by Electric Borrowers § 1717.653 Borrowers in default. Any borrower not in compliance with all provisions of its mortgage, loan contract, or any other agreements with RUS must,...

  6. 75 FR 60258 - Federal Acquisition Regulation; Termination for Default Reporting

    Science.gov (United States)

    2010-09-29

    ... Defective cost or pricing data. * * * * * (d) For each advisory audit received based on a postaward review... default and defective cost or pricing data, into the Past Performance Information System (PPIRS) and... included in PPIRS. Response: The Councils disagree. The Councils believe that defective cost or...

  7. A Comparative Study of Default Reasoning and Epistemic Processes

    Institute of Scientific and Technical Information of China (English)

    李未

    1993-01-01

    A comparative study between the theories of default reasoning and open logic is given.Some concepts of open logic,such as new premises,rejections by facts,reconstructions ,epistemic processes,and its limit are introduced to describe th evolution of hypotheses.An improved version of the limit theorem is given and proved.A model-theoretic interpretation of the closed normal defaults is given using the above concepts and the corresponding completeness is proved.Any extension of a closed normal default theory is proved to be the linit of a δ-partial increasing epistemic process of that theory,and vice versa.It is proved that there exist two distinct extensions of a closed normal default theory iff there is an δ-non-monotonic epistemic process of that theory.The completeness of Reiter's proof is also given and proved,in terms of the epistemic processes.Finally,the work is compared with Gaerdenfors's theory of knowledge in flux.

  8. Additive Intensity Regression Models in Corporate Default Analysis

    DEFF Research Database (Denmark)

    Lando, David; Medhat, Mamdouh; Nielsen, Mads Stenbo;

    2013-01-01

    We consider additive intensity (Aalen) models as an alternative to the multiplicative intensity (Cox) models for analyzing the default risk of a sample of rated, nonfinancial U.S. firms. The setting allows for estimating and testing the significance of time-varying effects. We use a variety of mo...

  9. The default mode network and altered consciousness in epilepsy.

    Science.gov (United States)

    Danielson, Nathan B; Guo, Jennifer N; Blumenfeld, Hal

    2011-01-01

    The default mode network has been hypothesized based on the observation that specific regions of the brain are consistently activated during the resting state and deactivated during engagement with task. The primary nodes of this network, which typically include the precuneus/posterior cingulate, the medial frontal and lateral parietal cortices, are thought to be involved in introspective and social cognitive functions. Interestingly, this same network has been shown to be selectively impaired during epileptic seizures associated with loss of consciousness. Using a wide range of neuroimaging and electrophysiological modalities, decreased activity in the default mode network has been confirmed during complex partial, generalized tonic-clonic, and absence seizures. In this review we will discuss these three seizure types and will focus on possible mechanisms by which decreased default mode network activity occurs. Although the specific mechanisms of onset and propagation differ considerably across these seizure types, we propose that the resulting loss of consciousness in all three types of seizures is due to active inhibition of subcortical arousal systems that normally maintain default mode network activity in the awake state. Further, we suggest that these findings support a general "network inhibition hypothesis", by which active inhibition of arousal systems by seizures in certain cortical regions leads to cortical deactivation in other cortical areas. This may represent a push-pull mechanism similar to that seen operating between cortical networks under normal conditions. PMID:21447899

  10. 24 CFR 207.256a - Reinstatement of defaulted mortgage.

    Science.gov (United States)

    2010-04-01

    ... the Commissioner, in the manner prescribed in 24 CFR part 200, subpart B. ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Reinstatement of defaulted mortgage... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND...

  11. Government interventions and default risk: Does one size fit all?

    NARCIS (Netherlands)

    Klomp, J.G.

    2013-01-01

    We examine the effectiveness of the financial sector rescue packages provided by the national governments during the 2008 financial crisis. This study questions the implicit assumption that government interventions have an uniform effect on the default risk of individual banks. After testing the res

  12. Cognitive and Emotional Modulation of Brain Default Operation

    Science.gov (United States)

    Pallesen, Karen Johanne; Brattico, Elvira; Bailey, Christopher J.; Korvenoja, Antti; Gjedde, Albert

    2009-01-01

    Goal-directed behavior lowers activity in brain areas that include the medial frontal cortex, the medial and lateral parietal cortex, and limbic and paralimbic brain regions, commonly referred to as the "default network." These activity decreases are believed to reflect the interruption of processes that are ongoing when the mind is in a restful…

  13. Sovereign default and the stability of inflation targeting regimes

    NARCIS (Netherlands)

    A. Schabert; S.J.G. van Wijnbergen

    2011-01-01

    We analyse the impact of interactions between monetary and fiscal policy on macroeconomic stability. We find that in the presence of sovereign default beliefs a monetary policy, which aims to stabilize inflation through an active interest rate policy, will destabilize the economy if the feedback fro

  14. Nonmonotonic Skeptical Consequence Relation in Constrained Default Logic

    Directory of Open Access Journals (Sweden)

    Mihaiela Lupea

    2010-12-01

    Full Text Available This paper presents a study of the nonmonotonic consequence relation which models the skeptical reasoning formalised by constrained default logic. The nonmonotonic skeptical consequence relation is defined using the sequent calculus axiomatic system. We study the formal properties desirable for a good nonmonotonic relation: supraclassicality, cut, cautious monotony, cumulativity, absorption, distribution. 

  15. Bilateral counterparty risk valuation with stochastic dynamical models and application to Credit Default Swaps

    OpenAIRE

    Damiano Brigo; Agostino Capponi

    2008-01-01

    We introduce the general arbitrage-free valuation framework for counterparty risk adjustments in presence of bilateral default risk, including default of the investor. We illustrate the symmetry in the valuation and show that the adjustment involves a long position in a put option plus a short position in a call option, both with zero strike and written on the residual net value of the contract at the relevant default times. We allow for correlation between the default times of the investor, ...

  16. Systematic equity-based credit risk: A CEV model with jump to default

    OpenAIRE

    Campi, Luciano; Polbennikov, Simon; Sbuelz, Alessandro

    2009-01-01

    We use equity as the traded primitive for a detailed analysis of systematic default risk. Default is parsimoniously represented by equity value hitting the zero barrier so that, unlike in reduced-form models, the explicit linkage to the firm's capital structure is preserved, but, unlike in structural models, restrictive assumptions on the structure are avoided. Default risk is either jump-like or diffusive. The equity price can jump to default. In line with recent empirical evidence on the ju...

  17. Modeling corporate defaults: Poisson autoregressions with exogenous covariates (PARX)

    DEFF Research Database (Denmark)

    Agosto, Arianna; Cavaliere, Guiseppe; Kristensen, Dennis;

    We develop a class of Poisson autoregressive models with additional covariates (PARX) that can be used to model and forecast time series of counts. We establish the time series properties of the models, including conditions for stationarity and existence of moments. These results are in turn used...... in the analysis of the asympotic properties of the maximum-likelihood estimators of the models. The PARX class of models is used to analyse the time series properties of monthly corporate defaults in the US in the period 1982-2011 using financial and economic variables as exogeneous covariates...... years economic and financial factors at the macro level are capable to explain a large portion of the correlation of US firms defaults over time....

  18. Default activity patterns at the neocortical microcircuit level

    Directory of Open Access Journals (Sweden)

    Artur Luczak

    2012-06-01

    Full Text Available Even in absence of sensory stimuli cortical networks exhibit complex, self-organized activity patterns. While the function of those spontaneous patterns of activation remains poorly understood, recent studies both in vivo and in vitro have demonstrated that neocortical neurons activate in a surprisingly similar sequential order both spontaneously and following input into cortex. For example, neurons that tend to fire earlier within spontaneous bursts of activity also fire earlier than other neurons in response to sensory stimuli. These 'default patterns' can last hundreds of milliseconds and are strongly conserved under a variety of conditions. In this paper we will review recent evidence for these default patterns at the local cortical level. We speculate that cortical architecture imposes common constraints on spontaneous and evoked activity flow, which result in the similarity of the patterns.

  19. Defaultable Game Options in a Hazard Process Model

    Directory of Open Access Journals (Sweden)

    Tomasz R. Bielecki

    2009-01-01

    Full Text Available The valuation and hedging of defaultable game options is studied in a hazard process model of credit risk. A convenient pricing formula with respect to a reference filteration is derived. A connection of arbitrage prices with a suitable notion of hedging is obtained. The main result shows that the arbitrage prices are the minimal superhedging prices with sigma martingale cost under a risk neutral measure.

  20. A value at risk analysis of credit default swaps

    OpenAIRE

    Scheicher, Martin; Raunig, Burkhard

    2008-01-01

    Kreditderivate wie Credit Default Swaps (CDS) haben in den letzten Jahren den Handel mit Kreditrisiko signifikant vereinfacht. Ein standardisiertes Kontrakt-Design, niedrige Transaktionskosten und eine große and heterogene Gruppe von Marktteilnehmern haben dazu beigetragen, dass CDS die Benchmark - Funktion für die Preisbestimmung im Markt für Unternehmens-Verschuldung erreichen. Heute ist der CDS das am meisten gehandelte Kreditderivat. Wir analysieren das Risiko von CDS, die im Handelsbuch ...

  1. The Role of Default Network Deactivation in Cognition and Disease

    OpenAIRE

    Anticevic, Alan; Cole, Michael W.; Murray, John D.; Corlett, Philip R.; Wang, Xiao-Jing; Krystal, John H.

    2012-01-01

    A considerable body of evidence has accumulated over recent years on the functions of the default-mode network (DMN) – a set of brain regions whose activity is high when the mind is not engaged in specific behavioral tasks and low during focused attention on the external environment. In this review, we focus on DMN suppression and its functional role in health and disease, summarizing evidence that spans several disciplines, including cognitive neuroscience, pharmacological neuroimaging, clin...

  2. Credit default swaps, bond spreads and the bond market

    OpenAIRE

    Zhu, Meicheng

    2014-01-01

    With the rapid development of the credit default swap (CDS) market, the issue of how the introduction of CDSs affects the corporate bond market has been of particular interest to researchers and policy makers. This has been investigated in the literature from two perspectives. One is to examine the relationship between the CDS and the bond markets in price discovery, and the other is concerned with researching the CDS trading effects on bond spreads. Referring to the former approach, most rel...

  3. Credit market shocks: evidence from corporate spreads and defaults

    OpenAIRE

    Roland Meeks

    2009-01-01

    Several recent papers have found that exogenous shocks to spreads paid in corporate credit markets are a substantial source of macroeconomic fluctuations. An alternative explanation of the data is that spreads respond endogenously to expectations of future default. We use a simple model of bond spreads to derive sign restrictions on the impulse-response functions of a VAR that identify credit shocks in the bond market, and compare them to results from a benchmark recursive VAR. We find that c...

  4. Techniques used on the credit derivatives market: credit default swaps.

    OpenAIRE

    Olléon-Assouan, E.

    2004-01-01

    As a response to the need for credit risk protection, the credit derivatives market has seen substantial growth over the past few years. While the deteriorating credit status of a large number of issuers in 2002 contributed to the expansion of this market, this growth can also be ascribed to the broadening of the uses to which these credit derivatives are put, above and beyond their original function of providing protection. This article describes how credit default swaps (CDSs) work and how ...

  5. Understanding Corporate Bond Spreads Using Credit Default Swaps

    OpenAIRE

    Alejandro Garcia; Jun Yang

    2009-01-01

    Corporate bond spreads worldwide have widened markedly since the beginning of the credit crisis in 2007. This article examines default and liquidity risk--the main components of the corporate bond spread--for Canadian firms that issue bonds in the U.S. market, focusing in particular on their evolution during the credit crisis. They find that, during this period, the liquidity component increased more for speculative-grade bonds than it did for investment-grade bonds, consistent with a "flight...

  6. Essays on corporate default process: UK and France

    OpenAIRE

    Nigam, Nirjhar

    2011-01-01

    The thesis has been conducted upon a unique and primary database manually collected through courts and various reliable sources (governmental and non-governmental offices). This is the major strength of this thesis. With such a database, we built individual statistics on the corporate bankruptcies process in for two major European countries (France and United Kingdom). The collected data deals with the causes of financial default, the recovery rates of creditors, the process of decision makin...

  7. Sovereign Default, Private Sector Creditors and the IFIs

    OpenAIRE

    Boz, Emine

    2009-01-01

    This paper builds a model of a sovereign borrower that has access to credit from private sector creditors and an IFI. Private sector creditors and the IFI offer different debt contracts that are modelled based on the institutional frameworks of these two types of debt. We analyze the decisions of a sovereign on how to allocate its borrowing needs between these two types of creditors, and when to default on its debt to the private sector creditor. The numerical analysis shows that, consistent ...

  8. Asset Pricing When Risk Sharing is Limited by Default

    OpenAIRE

    Fernando Alvarez; Urban J. Jermann

    2010-01-01

    We study the asset pricing implications of a multi-agent endowment economy where agents can default on contracts that would leave them otherwise worse off. We specialize and extend the environment studied by Kocherlakota (1995) and Kehoe and Levine (1993) to make it comparable to standard studies of asset pricing. We make contributions along two fronts. First, we extend the characterization of efficient allocations. Second, we present an equilibrium concept with complete markets and with endo...

  9. SOVEREIGN CREDIT RISK and CREDIT DEFAULT SWAP SPREAD REFLECTIONS

    OpenAIRE

    TURGUTTOPBAŞ, Neslihan

    2015-01-01

    The already experienced turbulence in the global financial system has focused the attentions of market participants to especially sovereign risk; its major determinants, systematic nature as well as its contagion potential. In this study, the direction of the analysis of the sovereign risk is within the framework of the credit default swap (cds) transactions. The sovereign risk can also be elaborated by using the bond spreads of the sovereign but the latter is also driven by factors other tha...

  10. Determinants of Banking Credit Default in Indonesia: A Comparative Analysis

    OpenAIRE

    Muhammad Imaduddin

    2008-01-01

    This study aims to analyze the determinants of Islamic banking credit default compared with conventional banking in Indonesia. This study utilized timeseries analysis, by which ordinary least square method is adopted. 40 monthly data observations from January 2003 until April 2006 are used. The study is divided into two models, namely Islamic banking model and conventional banking model. The values of non-performing financing (NPF) in Islamic banking and non-performing loan (NPL) in conventio...

  11. Do student loan borrowers opportunistically default? Evidence from bankruptcy reform

    OpenAIRE

    Darolia, Rajeev; Ritter, Dubravka

    2015-01-01

    Bankruptcy reform in 2005 eliminated debtors’ ability to discharge private student loan debt in bankruptcy. This law aimed to reduce costly defaults by diminishing the perceived incentive of some private student loan borrowers to declare bankruptcy even if they had sufficient income to service their debt. Using a unique, nationally representative sample of anonymized credit bureau files, we examine the bankruptcy filing and delinquency rates of private student loan borrowers in response to th...

  12. Recovering portfolio default intensities implied by CDO quotes

    OpenAIRE

    Cont, Rama; Minca, Andreea

    2013-01-01

    We propose a stable non-parametric algorithm for the calibration of pricing models for portfolio credit derivatives: given a set of observations of market spreads for CDO tranches, we construct a risk-neutral default intensity process for the portfolio underlying the CDO which matches these observations, by looking for the risk neutral loss process 'closest' to a prior loss process, verifying the calibration constraints. We formalize the problem in terms of minimization of relative entropy wi...

  13. Implied default risk in European interbank lending markets

    OpenAIRE

    Chan, Celene

    2011-01-01

    This project analyzes the spread arising from trading in two portfolios based on the European debt and interbank lending markets. The analysis uses data on sovereign credit default swap spreads, zero-coupon bond yields, European Interbank Offered Rate (EURIBOR) and Euro-denominated plain vanilla interest rate swaps. I focus on the countries that are most embroiled in the European debt crisis: Portugal, Italy, Greece and Spain. The first portfolio I study contains a long position in a 5-year s...

  14. Straight debt issuance announcement effects on credit default swap spreads

    OpenAIRE

    Kaarela, Ilari

    2014-01-01

    This thesis studies the effect of straight debt issuance announcements on credit default swap (CDS) spreads. As leverage-increasing capital structure decisions, debt issuances should result in increases of credit risk, and thus in CDS and credit spreads. Leverage is, after all, both theoretically and empirically an important determinant of credit risk. However, previous literature fails to show a significant effect on credit spreads around debt issuances. When does price adjustment of cr...

  15. Abnormal Default System Functioning in Depression: Implications for Emotion Regulation.

    Science.gov (United States)

    Messina, Irene; Bianco, Francesca; Cusinato, Maria; Calvo, Vincenzo; Sambin, Marco

    2016-01-01

    Depression is widely seen as the result of difficulties in regulating emotions. Based on neuroimaging studies on voluntary emotion regulation, neurobiological models have focused on the concept of cognitive control, considering emotion regulation as a shift toward involving controlled processes associated with activation of the prefrontal and parietal executive areas, instead of responding automatically to emotional stimuli. According to such models, the weaker executive area activation observed in depressed patients is attributable to a lack of cognitive control over negative emotions. Going beyond the concept of cognitive control, psychodynamic models describe the development of individuals' capacity to regulate their emotional states in mother-infant interactions during childhood, through the construction of the representation of the self, others, and relationships. In this mini-review, we link these psychodynamic models with recent findings regarding the abnormal functioning of the default system in depression. Consistently with psychodynamic models, psychological functions associated with the default system include self-related processing, semantic processes, and implicit forms of emotion regulation. The abnormal activation of the default system observed in depression may explain the dysfunctional aspects of emotion regulation typical of the condition, such as an exaggerated negative self-focus and rumination on self-esteem issues. We also discuss the clinical implications of these findings with reference to the therapeutic relationship as a key tool for revisiting impaired or distorted representations of the self and relational objects. PMID:27375536

  16. Abnormal Default System Functioning in Depression: Implications for Emotion Regulation

    Science.gov (United States)

    Messina, Irene; Bianco, Francesca; Cusinato, Maria; Calvo, Vincenzo; Sambin, Marco

    2016-01-01

    Depression is widely seen as the result of difficulties in regulating emotions. Based on neuroimaging studies on voluntary emotion regulation, neurobiological models have focused on the concept of cognitive control, considering emotion regulation as a shift toward involving controlled processes associated with activation of the prefrontal and parietal executive areas, instead of responding automatically to emotional stimuli. According to such models, the weaker executive area activation observed in depressed patients is attributable to a lack of cognitive control over negative emotions. Going beyond the concept of cognitive control, psychodynamic models describe the development of individuals’ capacity to regulate their emotional states in mother-infant interactions during childhood, through the construction of the representation of the self, others, and relationships. In this mini-review, we link these psychodynamic models with recent findings regarding the abnormal functioning of the default system in depression. Consistently with psychodynamic models, psychological functions associated with the default system include self-related processing, semantic processes, and implicit forms of emotion regulation. The abnormal activation of the default system observed in depression may explain the dysfunctional aspects of emotion regulation typical of the condition, such as an exaggerated negative self-focus and rumination on self-esteem issues. We also discuss the clinical implications of these findings with reference to the therapeutic relationship as a key tool for revisiting impaired or distorted representations of the self and relational objects. PMID:27375536

  17. Corporate Yield Spreads: Default Risk or Liquidity? New Evidence from the Credit-Default Swap Market, previously titled: "The Credit-Default Swap Market: Is Credit Protection Priced Correctly?"

    OpenAIRE

    Francis A. Longstaff; Mithal, Sanjay; Neis, Eric

    2004-01-01

    We use the information in credit-default swaps to obtain direct measures of the size of the default and nondefault components in corporate spreads. We find that the majority of the corporate spread is due to default risk. This result holds for all rating categories and is robust to the definition of the riskless curve. We also find that the nondefault component is time varying and strongly related to measures of bond-specific illiquidity as well as to macroeconomic measures of bond-market liq...

  18. MULTI-FACTOR APPROACH FOR PRICING BASKET CREDIT LINKED NOTES UNDER ISSUER DEFAULT RISK

    OpenAIRE

    Po-Cheng Wu

    2011-01-01

    This article proposes a multi-factor approach to incorporate issuer default risk into basket credit linked note (BCLN) pricing based on the Gaussian copula. The numerical analysis demonstrates that the issuer default risk increases the fair coupon rate. Contradicting the common belief that a positive default correlation between reference entities and an issuer increases the possibility of double losses and disfavors the BCLN holder, thereby driving up the BCLN coupon rate, analytical results ...

  19. Default risk sharing between banks and markets : the contribution of collateralized debt obligations

    OpenAIRE

    Franke, Günter; Krahnen, Jan Pieter

    2005-01-01

    This paper contributes to the economics of financial institutions risk management by exploring how loan securitization a.ects their default risk, their systematic risk, and their stock prices. In a typical CDO transaction a bank retains through a first loss piece a very high proportion of the expected default losses, and transfers only the extreme losses to other market participants. The size of the first loss piece is largely driven by the average default probability of the securitized asset...

  20. Definition and characterization of an extended social-affective default network

    OpenAIRE

    Amft, Maren; Bzdok, Danilo; Laird, Angela R.; Fox, Peter T.; Schilbach, Leonhard; Eickhoff, Simon B.

    2014-01-01

    Recent evidence suggests considerable overlap between the default mode network (DMN) and regions involved in social, affective and introspective processes. We considered these overlapping regions as the social-affective part of the default mode network. In this study we established a robust mapping of the underlying brain network formed by these regions and those strongly connected to them (the extended social-affective default network: eSAD). We first seeded meta-analytic connectivity modeli...

  1. 金融双语信用违约互换%Credit Default Swaps

    Institute of Scientific and Technical Information of China (English)

    刘超

    2007-01-01

    @@ Credit default swaps can be thought of as an insurance against the default of some underlying instrument1, or as a put option on the underlying instrument. In a typical credit default swap, as shown in figure, the party selling the credit risk (or the "protection buyer") makes periodic payments to the "protection seller" of a negotiated number of basis points , times the notional amount of the underlying bond or loan.

  2. Default probabilities and expected recovery: an analysis of emerging market sovereign bonds

    OpenAIRE

    Liz Dixon-Smith; Roman Goossens; Simon Hayes

    2005-01-01

    We develop a simple bond pricing model to map the prices of individual EME sovereign bonds into term structures of implied (risk-neutral) default probabilities and expected recovery rates. Simple indices of bond spreads are found to be closely correlated with long-term risk neutral default probabilities, so may provide a straightforward way of monitoring shifts in investors' perceptions. But short-term risk neutral default probabilities behave quite differently, implying that there are period...

  3. The Interplay Between Student Loans and Credit Card Debt: Implications for Default in the Great Recession

    OpenAIRE

    Ionescu, Felicia; Ionescu, Marius

    2014-01-01

    We analyze the interactions between two different forms of unsecured credit and their implications for default behavior of young U.S. households. One type of credit mimics credit cards in the United States and the default option resembles a bankruptcy filing under Chapter 7; the other type of credit mimics student loans in the United States and the default option resembles Chapter 13. In the credit card market a financial intermediary offers a menu of interest rates based on individual defaul...

  4. The Significance of the Default Mode Network (DMN) in Neurological and Neuropsychiatric Disorders: A Review

    Science.gov (United States)

    Mohan, Akansha; Roberto, Aaron J.; Mohan, Abhishek; Lorenzo, Aileen; Jones, Kathryn; Carney, Martin J.; Liogier-Weyback, Luis; Hwang, Soonjo; Lapidus, Kyle A.B.

    2016-01-01

    The relationship of cortical structure and specific neuronal circuitry to global brain function, particularly its perturbations related to the development and progression of neuropathology, is an area of great interest in neurobehavioral science. Disruption of these neural networks can be associated with a wide range of neurological and neuropsychiatric disorders. Herein we review activity of the Default Mode Network (DMN) in neurological and neuropsychiatric disorders, including Alzheimer’s disease, Parkinson’s disease, Epilepsy (Temporal Lobe Epilepsy - TLE), attention deficit hyperactivity disorder (ADHD), and mood disorders. We discuss the implications of DMN disruptions and their relationship to the neurocognitive model of each disease entity, the utility of DMN assessment in clinical evaluation, and the changes of the DMN following treatment.

  5. Some determinants of the price of default risk

    OpenAIRE

    Anderson, Ronald W.

    2008-01-01

    In this paper we study the pricing of credit risk as reflected in the market for credit default swaps (CDS) between 2003 and 2008. This market has newly emerged as the reference for credit risk pricing because of its use of standardized contract specifications and has achieved a higher level of liquidity than typically prevails in the markets for the underlying notes and bonds of the named corporate issuers. We initiate our exploration by studying a particular case which allows us to set out ...

  6. Basel II and default risk: An empirical analysis

    OpenAIRE

    Luppi Barbara; Marzo Massimiliano; Scorcu Antonello

    2009-01-01

    The New Accord on Capital, known as Basel II, has induced a progressive harmonization of evaluation processes on credit risk merit in Italy. The present work analyzes the effect of Basel II on the basis of the definition of default that will come into effect at the end of the transition period. The analysis is based on a representative sample of a retail portfolio of one major Italian bank and distinguishes Northern, Central and Southern Italy. The findings highlight that under the new defini...

  7. Cognitive and emotional modulation of brain default operation

    DEFF Research Database (Denmark)

    Pallesen, Karen Johanne; Brattico, Elvira; Bailey, Christopher J;

    2009-01-01

    cognitive load and emotional stimulus connotation on task-related decreases in the default network by employing an auditory working memory (WM) task with musical sounds. The performance of the WM task, compared to passive listening, lowered the activity in medial and lateral, prefrontal, parietal, temporal...... dissonant musical sounds, there was an interaction between the experimental condition and the stimulus type. The current results are consistent with the previously reported effect of task difficulty on task-related brain activation decreases. The results also indicate that task-related decreases may...

  8. On the Parameterized Complexity of Default Logic and Autoepistemic Logic

    CERN Document Server

    Meier, Arne; Thomas, Michael; Vollmer, Heribert

    2011-01-01

    We investigate the application of Courcelle's Theorem and the logspace version of Elberfeld etal. in the context of the implication problem for propositional sets of formulae, the extension existence problem for default logic, as well as the expansion existence problem for autoepistemic logic and obtain fixed-parameter time and space efficient algorithms for these problems. On the other hand, we exhibit, for each of the above problems, families of instances of a very simple structure that, for a wide range of different parameterizations, do not have efficient fixed-parameter algorithms (even in the sense of the large class XPnu), unless P=NP.

  9. Valuing Credit Default Swap under a double exp onential jump diff usion model

    Institute of Scientific and Technical Information of China (English)

    YANG Rui-cheng; PANG Mao-xiu; JIN Zhuang

    2014-01-01

    This paper discusses the valuation of the Credit Default Swap based on a jump market, in which the asset price of a firm follows a double exponential jump diff usion process, the value of the debt is driven by a geometric Brownian motion, and the default barrier follows a continuous stochastic process. Using the Gaver-Stehfest algorithm and the non-arbitrage asset pricing theory, we give the default probability of the first passage time, and more, derive the price of the Credit Default Swap.

  10. Cognitive and emotional modulation of brain default operation.

    Science.gov (United States)

    Pallesen, Karen Johanne; Brattico, Elvira; Bailey, Christopher J; Korvenoja, Antti; Gjedde, Albert

    2009-06-01

    Goal-directed behavior lowers activity in brain areas that include the medial frontal cortex, the medial and lateral parietal cortex, and limbic and paralimbic brain regions, commonly referred to as the "default network." These activity decreases are believed to reflect the interruption of processes that are ongoing when the mind is in a restful state. Previously, the nature of these processes was probed by varying cognitive task parameters, but the presence of emotional processes, while often assumed, was little investigated. With fMRI, we studied the effect of systematic variations of both cognitive load and emotional stimulus connotation on task-related decreases in the default network by employing an auditory working memory (WM) task with musical sounds. The performance of the WM task, compared to passive listening, lowered the activity in medial and lateral, prefrontal, parietal, temporal, and limbic regions. In a subset of these regions, the magnitude of decrease depended on the memory load; the greater the cognitive load, the larger the magnitude of the observed decrease. Furthermore, in the right amygdala and the left precuneus, areas previously associated with processing of unpleasant dissonant musical sounds, there was an interaction between the experimental condition and the stimulus type. The current results are consistent with the previously reported effect of task difficulty on task-related brain activation decreases. The results also indicate that task-related decreases may be further modulated by the emotional stimulus connotation. PMID:18752396

  11. Abnormal functional connectivity of default mode sub-networks in autism spectrum disorder patients.

    Science.gov (United States)

    Assaf, Michal; Jagannathan, Kanchana; Calhoun, Vince D; Miller, Laura; Stevens, Michael C; Sahl, Robert; O'Boyle, Jacqueline G; Schultz, Robert T; Pearlson, Godfrey D

    2010-10-15

    Autism spectrum disorders (ASDs) are characterized by deficits in social and communication processes. Recent data suggest that altered functional connectivity (FC), i.e. synchronous brain activity, might contribute to these deficits. Of specific interest is the FC integrity of the default mode network (DMN), a network active during passive resting states and cognitive processes related to social deficits seen in ASD, e.g. Theory of Mind. We investigated the role of altered FC of default mode sub-networks (DM-SNs) in 16 patients with high-functioning ASD compared to 16 matched healthy controls of short resting fMRI scans using independent component analysis (ICA). ICA is a multivariate data-driven approach that identifies temporally coherent networks, providing a natural measure of FC. Results show that compared to controls, patients showed decreased FC between the precuneus and medial prefrontal cortex/anterior cingulate cortex, DMN core areas, and other DM-SNs areas. FC magnitude in these regions inversely correlated with the severity of patients' social and communication deficits as measured by the Autism Diagnostic Observational Schedule and the Social Responsiveness Scale. Importantly, supplemental analyses suggest that these results were independent of treatment status. These results support the hypothesis that DM-SNs under-connectivity contributes to the core deficits seen in ASD. Moreover, these data provide further support for the use of data-driven analysis with resting-state data for illuminating neural systems that differ between groups. This approach seems especially well suited for populations where compliance with and performance of active tasks might be a challenge, as it requires minimal cooperation. PMID:20621638

  12. Altered effective connectivity within default mode network in major depression disorder

    Science.gov (United States)

    Li, Liang; Li, Baojuan; Bai, Yuanhan; Wang, Huaning; Zhang, Linchuan; Cui, Longbiao; Lu, Hongbing

    2016-03-01

    Understanding the neural basis of Major Depressive Disorder (MDD) is important for the diagnosis and treatment of this mental disorder. The default mode network (DMN) is considered to be highly involved in the MDD. To find directed interaction between DMN regions associated with the development of MDD, the effective connectivity within the DMN of the MDD patients and matched healthy controls was estimated by using a recently developed spectral dynamic causal modeling. Sixteen patients with MDD and sixteen matched healthy control subjects were included in this study. While the control group underwent the resting state fMRI scan just once, all patients underwent resting state fMRI scans before and after two months' treatment. The spectral dynamic causal modeling was used to estimate directed connections between four DMN nodes. Statistical analysis on connection strengths indicated that efferent connections from the medial frontal cortex (MFC) to posterior cingulate cortex (PCC) and to right parietal cortex (RPC) were significant higher in pretreatment MDD patients than those of the control group. After two-month treatment, the efferent connections from the MFC decreased significantly, while those from the left parietal cortex (LPC) to MFC, PCC and RPC showed a significant increase. These findings suggest that the MFC may play an important role for inhibitory conditioning of the DMN, which was disrupted in MDD patients. It also indicates that disrupted suppressive function of the MFC could be effectively restored after two-month treatment.

  13. The single risk factor approach to capital charges in case of correlated loss given default rates

    OpenAIRE

    Dirk Tasche

    2004-01-01

    A new methodology for incorporating LGD correlation effects into the Basel II risk weight functions is introduced. This methodology is based on modelling of LGD and default event with a single loss variable. The resulting formulas for capital charges are numerically compared to the current proposals by the Basel Committee on Banking Supervision. Keywords: Regulatory capital charge, loss given default (LGD).

  14. 40 CFR 13.19 - Analysis of costs; automation; prevention of overpayments, delinquencies or defaults.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Analysis of costs; automation; prevention of overpayments, delinquencies or defaults. 13.19 Section 13.19 Protection of Environment...; automation; prevention of overpayments, delinquencies or defaults. (a) The Administrator may...

  15. 5 CFR 185.110 - Default upon failure to file an answer.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Default upon failure to file an answer. 185.110 Section 185.110 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PROGRAM FRAUD CIVIL REMEDIES § 185.110 Default upon failure to file an answer. (a) If...

  16. Default Rate on Student Loans Drops for 6th Consecutive Year.

    Science.gov (United States)

    Burd, Stephen

    1998-01-01

    The student loan default rate was 9.6% in 1996, a decline of 12.8% since the 1990 peak, saving the federal government $3 billion over six years. Since 1993 the Department of Education has barred 1065 institutions, mostly for-profit trade schools, from participating in federal student loan programs; institutions with a 40% default rate can lose…

  17. 34 CFR 668.188 - Preventing evasion of the consequences of cohort default rates.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Preventing evasion of the consequences of cohort... Two Year Cohort Default Rates § 668.188 Preventing evasion of the consequences of cohort default rates... institution, the same person (as defined in 34 CFR 600.31) or members of that person's family, directly...

  18. 34 CFR 668.207 - Preventing evasion of the consequences of cohort default rates.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Preventing evasion of the consequences of cohort... Cohort Default Rates § 668.207 Preventing evasion of the consequences of cohort default rates. (a... institution, the same person (as defined in 34 CFR 600.31) or members of that person's family, directly...

  19. 75 FR 72660 - Extension of Temporary Exemptions for Eligible Credit Default Swaps To Facilitate Operation of...

    Science.gov (United States)

    2010-11-26

    ...We are extending the expiration dates in our temporary rules that provide exemptions under the Securities Act of 1933, the Securities Exchange Act of 1934, and the Trust Indenture Act of 1939 for certain credit default swaps in order to continue facilitating the operation of one or more central counterparties for those credit default swaps until the implementation of the clearing provisions of......

  20. Determinants of Banking Credit Default in Indonesia: A Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Muhammad Imaduddin

    2008-08-01

    Full Text Available This study aims to analyze the determinants of Islamic banking credit default compared with conventional banking in Indonesia. This study utilized timeseries analysis, by which ordinary least square method is adopted. 40 monthly data observations from January 2003 until April 2006 are used. The study is divided into two models, namely Islamic banking model and conventional banking model. The values of non-performing financing (NPF in Islamic banking and non-performing loan (NPL in conventional banking are treated as the dependent variables. The results showed that two-month lagged of non-performing financing (NPF, total asset (ASSET, the amount of thirdparty-funds (TPF, one-month lagged of total financing (DFIN, and growthof gross-domestic product (GDPG variables have significant impact to the ratio of non-performing financing (NPF in Islamic banking. Meanwhile, the three-month lagged of non-performing loan (DDDNPL, total asset (CASSET, three-month as well as two-month period lagged of total loan (DDDCRED and DDCRED, inter-bank money market (PUAB, and growth of gross-domestic (GDPG are significant to influence the ratio of non-performing loan (NPL in conventional banking. The result also implied that the general election in 2004 had a significant influence to the ratio of non-performing financing (NPF in Islamic banking.Even tough from the outset, it seems Islamic banking has a better performance than conventional banking by having a relatively low NPF, this study, however, has found the opposite. Albeit, Islamic banking showing a good long-runas well as short-run dynamics among all variables in the beginning, after modifying the model into autoregressive in the main analysis, results showed that conventional banking has a better performance than Islamic banking with higher correlation of determination. In this regard, we cannot assume thatIslamic banking is performing poorly in managing credit default problems. This is because the result

  1. Regression And Time Series Analysis Of Loan Default At Minescho Cooperative Credit Union Tarkwa

    Directory of Open Access Journals (Sweden)

    Otoo

    2015-08-01

    Full Text Available Abstract Lending in the form of loans is a principal business activity for banks credit unions and other financial institutions. This forms a substantial amount of the banks assets. However when these loans are defaulted it tends to have serious effects on the financial institutions. This study sought to determine the trend and forecast loan default at Minescho CreditUnion Tarkwa. A secondary data from the Credit Union was analyzed using Regression Analysis and the Box-Jenkins method of Time Series. From the Regression Analysis there was a moderately strong relationship between the amount of loan default and time. Also the amount of loan default had an increasing trend. The two years forecast of the amount of loan default oscillated initially and remained constant from 2016 onwards.

  2. Top management turnover and firm default risk:Evidence from the Chinese securities market

    Institute of Scientific and Technical Information of China (English)

    Wei; Ting

    2011-01-01

    China has moved rapidly from a socialist planned economy to a market economy.As a result,many enterprises in China are seeking talented top management to increase their performance and decrease their default risk.Studies abound regarding top management turnover and its relationship with firm performance,however,few studies have connected top management turnover with firm default risk.In China,a market with extensive financial fraud,firm default risk is an important factor and thus we explore this relationship in the Chinese securities market.Our results indicate that firms with higher default risk are more likely to change their top management in the next financial reporting period.In addition,following changes in top management,such firms default less than other companies.

  3. Optimal investment under multiple defaults risk: a BSDE-decomposition approach

    CERN Document Server

    Jiao, Ying; Pham, Huyên

    2011-01-01

    We study an optimal investment problem under contagion risk in a financial model subject to multiple jumps and defaults. The global market information is formulated as progressive enlargement of a default-free Brownian filtration, and the dependence of default times is modelled by a conditional density hypothesis. In this It\\^o-jump process model, we give a decomposition of the corresponding stochastic control problem into stochastic control problems in the default-free filtration, which are determined in a backward induction. The dynamic programming method leads to a backward recursive system of quadratic Backward Stochastic Differential Equations (BSDEs) in Brownian filtration, and our main result is to prove under fairly general conditions the existence and uniqueness of a solution to this system, which characterizes explicitly the value function and optimal strategies to the optimal investment problem. We illustrate our solutions approach with some numerical tests emphasizing the impact of default intensi...

  4. Clinical research in the treatment of tuberculosis: current status and future prospects.

    Science.gov (United States)

    Chang, K-C; Yew, W-W; Sotgiu, G

    2015-12-01

    To supplement previous state-of-art reviews on anti-tuberculosis treatment and to pave the way forward with reference to the current status, we systematically reviewed published literature on clinical research on tuberculosis (TB) over the past decade in the treatment of drug-susceptible and multidrug-resistant TB (MDR-TB), with a focus on drugs, dosing factors and regimens. Our review was restricted to Phase II/III clinical trials, cohort and case-control studies, and systematic reviews of clinical studies. TB programmatic and patient behavioural factors, non-TB drugs, adjunctive surgery, new vaccines, immunotherapy, antiretroviral therapy and management of latent tuberculous infection are outside the scope of this review. An algorithm was used to systematically search PubMed for relevant articles published in English from 1 January 2005 to 31 December 2014. Articles without evaluated factors (drugs, dosing factors and regimens) or comparative analysis of specified anti-tuberculosis treatment outcomes were excluded. Of the 399 articles initially identified, 294 were excluded. The main findings of the remaining 105 articles are described under two categories: presumed drug-susceptible TB and MDR-TB. Fifty-nine articles included under drug-susceptible TB were divided into 12 subcategories: isoniazid, rifampicin, pyrazinamide, fluoroquinolones, fixed-dose combination drugs, dosing frequency, treatment phases, treatment duration, experimental regimens for pulmonary (surrogate markers vs. clinical outcomes) and extra-pulmonary TB. Forty-nine articles included under MDR-TB were divided into seven subcategories: fluoroquinolones, pyrazinamide, second-line injectable drugs, World Health Organization Group 4 and Group 5 drugs, MDR-TB regimens and novel drugs. Clinical research in the last decade and ongoing trials might furnish new paradigms for improving the treatment of this recalcitrant ancient disease. PMID:26614181

  5. Empirical analysis of structural change in Credit Default Swap volatility

    International Nuclear Information System (INIS)

    The purpose of this paper is to study the structural change in Credit Default Swap volatility. We use statistical properties and a network approach to better understand the behavior of CDS volatility. We hypothesize that structural change occurs in CDS index during a financial crisis and it requires subperiod analysis, rather than full period analysis, to investigate properly. Our results show that the probability of large volatility is related to the structure of volatility but it is more significantly related to the size of volatility. Both the memory property and the size of volatility are confirmed to have dependence on the structure of volatility. The linked degree of CDS volatilities is highly related to the probability of large volatility and its predictability, regardless of structural change in volatility. Another interesting result is that the CDS volatility of a country is more related to the behavior of other volatilities, not the geographical location

  6. Is religious fundamentalism our default spirituality?: Implications for teacher education

    Directory of Open Access Journals (Sweden)

    Ferdinand J. Potgieter

    2014-02-01

    Full Text Available Using experiential interpretivism as underpinning methodology, this article investigates whether religious fundamentalism is the default spirituality of human beings. Our research is based on a hermeneutic reconstructive interpretation of religion, fundamentalism, radicalism, extremism, spirituality, life- and worldview, and the role of education in bringing about peaceful coexistence amongst people. We concluded that the natural religious-fundamentalist inclination of the human being tends to be (and needs to be counterbalanced by the education – that is, socialisation – that he or she receives from the moment of birth, the important first six or seven years of life, and throughout his or her life. Based on this conclusion, the article ends with the articulation of ten implications for teacher education.

  7. Default risk modeling beyond the first-passage approximation: extended Black-Cox model.

    Science.gov (United States)

    Katz, Yuri A; Shokhirev, Nikolai V

    2010-07-01

    We develop a generalization of the Black-Cox structural model of default risk. The extended model captures uncertainty related to firm's ability to avoid default even if company's liabilities momentarily exceeding its assets. Diffusion in a linear potential with the radiation boundary condition is used to mimic a company's default process. The exact solution of the corresponding Fokker-Planck equation allows for derivation of analytical expressions for the cumulative probability of default and the relevant hazard rate. Obtained closed formulas fit well the historical data on global corporate defaults and demonstrate the split behavior of credit spreads for bonds of companies in different categories of speculative-grade ratings with varying time to maturity. Introduction of the finite rate of default at the boundary improves valuation of credit risk for short time horizons, which is the key advantage of the proposed model. We also consider the influence of uncertainty in the initial distance to the default barrier on the outcome of the model and demonstrate that this additional source of incomplete information may be responsible for nonzero credit spreads for bonds with very short time to maturity. PMID:20866698

  8. EMPIRICAL STUDY OF THE PROBABILITY OF DEFAULT IN CASE OF ROMANIAN COMPANIES LISTED ON STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    Marton Noemi, Racz Timea Erzsebet

    2011-07-01

    Full Text Available The importance of estimation of a firm's probability of default increased significantly during the economic and financial crisis for financial institutions, which can be explained by the fact that the share of nonperforming loans increased in this period. The probability of default can be estimated with structural models, which have on base the methodology developed by Merton (1974, methodology used by Moody's Corporation (known as KMV Merton model. The aim of this study is to estimate the probability of default of companies listed on Bucharest Stock Exchange using this methodology. This approach was widely used in the literature by many researchers (i.e., Kealhofer and Kurbat (2000, Crosbie and Bohn (2002, Duffie and Wang (2004, Bharath and Shumway (2004, 2008. In Romania this methodology was empirically tested by Codirlaşu (2007, who estimated using Merton's methodology the probability of default of companies listed on the Bucharest Stock Exchange, respectively by Bobircă et al. (2008, where the probabilities of default were estimated in case of 42 companies listed on the Bucharest Stock Exchange for 2000-2008 time period. In this paper we used Merton's model, which assumes that a company defaults if the value of its assets is less than the promised dept repayment at time T. The process of estimating the probability of default starts from the following firm specific variables: the market value of the firm's assets, the share prices, the value of the liabilities and the risk-free rate. The analyzed period is 2003-2010, containing the economic and financial crisis period, too. Analyzing the financial statements of the companies listed on the Bucharest Stock Exchange, we determined the input parameters of the model and calculated the quarterly probabilities of default of each analyzed company. According to our results the probabilities of default have a reduced value in the majority of the cases.

  9. Comparison of the safety and efficacy of a fixed-dose combination regimen and separate formulations for pulmonary tuberculosis treatment

    Directory of Open Access Journals (Sweden)

    Jiun-Ting Wu

    2015-06-01

    Full Text Available OBJECTIVES: Fixed-dose combination formulations, which simplify the administration of drugs and prevent the development of drug resistance, have been recommended as a standard anti-tuberculosis treatment regimen. However, the composition and dosage recommendations for fixed-dose combination formulations differ from those for separate formulations. Thus, questions about the effectiveness and side effects of combination formulations remain. The aim of this study was to compare the safety and efficacy of these two types of anti-tuberculosis regimens for pulmonary tuberculosis treatment. METHOD: A prospective, randomized controlled study was conducted using the directly observed treatment short-course strategy. Patients were randomly allocated to one of two short-course regimens. One year after completing the treatment, these patients’ outcomes were analyzed. ClinicalTrials.gov: NCT00979290. RESULTS: A total of 161 patients were enrolled, 142 of whom were evaluable for safety assessment. The two regimens had a similar incidence of adverse effects. In the per-protocol population, serum bilirubin concentrations at the peak level, at week 4, and at week 8 were significantly higher for the fixed-dose combination formulation than for the separate formulations. All patients had negative sputum cultures at the end of the treatment, and no relapse occurred after one year of follow-up. CONCLUSIONS: In this randomized study, transient higher serum bilirubin levels were noted for the fixed-dose combination regimen compared with the separate formulations during treatment. However, no significant difference in safety or efficacy was found between the groups when the directly observed treatment short-course strategy was used.

  10. The Interplay Between Different Types of Unsecured Credit and Amplification of Consumer Default

    OpenAIRE

    Felicia Ionescu

    2011-01-01

    We analyse, theoretically and quantitatively, the interactions between different forms of unsecured credit and their implications for default behaviour of young U.S. households. One type of credit mimics credit cards in the U.S. and the default option resembles a bankruptcy filing under Chapter 7 and the other type mimics student loans in the U.S. and the default option resembles Chapter 13 of the U.S. Bankruptcy Code. In the credit card market financial intermediary offers a menu of credit l...

  11. The Interplay Between Student Loans and Credit Cards: Implications for Default

    OpenAIRE

    Felicia Ionescu; Marius Ionescu

    2012-01-01

    We analyze, theoretically and quantitatively, the interactions between two different forms of unsecured credit and their implications for default behavior of young U.S. households. One type of credit mimics credit cards in the U.S. and the default option resembles a bankruptcy filing under Chapter 7 and the other type of credit mimics student loans in the U.S. and the default option resembles Chapter 13 of the U.S. Bankruptcy Code. In the credit card market financial intermediary offers a men...

  12. Uniqueness of Viscosity Solutions for Optimal Multi-Modes Switching Problem with Risk of default

    CERN Document Server

    Asri, Brahim El

    2012-01-01

    In this paper we study the optimal m-states switching problem in finite horizon as well as infinite horizon with risk of default. We allow the switching cost functionals and cost of default to be of polynomial growth and arbitrary. We show uniqueness of a solution for a system of m variational partial differential inequalities with inter-connected obstacles. This system is the deterministic version of the Verification Theorem of the Markovian optimal m-states switching problem with risk of default. This problem is connected with the valuation of a power plant in the energy market.

  13. Benchmark Simulation Model No 2: finalisation of plant layout and default control strategy.

    Science.gov (United States)

    Nopens, I; Benedetti, L; Jeppsson, U; Pons, M-N; Alex, J; Copp, J B; Gernaey, K V; Rosen, C; Steyer, J-P; Vanrolleghem, P A

    2010-01-01

    The COST/IWA Benchmark Simulation Model No 1 (BSM1) has been available for almost a decade. Its primary purpose has been to create a platform for control strategy benchmarking of activated sludge processes. The fact that the research work related to the benchmark simulation models has resulted in more than 300 publications worldwide demonstrates the interest in and need of such tools within the research community. Recent efforts within the IWA Task Group on "Benchmarking of control strategies for WWTPs" have focused on an extension of the benchmark simulation model. This extension aims at facilitating control strategy development and performance evaluation at a plant-wide level and, consequently, includes both pretreatment of wastewater as well as the processes describing sludge treatment. The motivation for the extension is the increasing interest and need to operate and control wastewater treatment systems not only at an individual process level but also on a plant-wide basis. To facilitate the changes, the evaluation period has been extended to one year. A prolonged evaluation period allows for long-term control strategies to be assessed and enables the use of control handles that cannot be evaluated in a realistic fashion in the one week BSM1 evaluation period. In this paper, the finalised plant layout is summarised and, as was done for BSM1, a default control strategy is proposed. A demonstration of how BSM2 can be used to evaluate control strategies is also given. PMID:21045320

  14. Default network connectivity decodes brain states with simulated microgravity.

    Science.gov (United States)

    Zeng, Ling-Li; Liao, Yang; Zhou, Zongtan; Shen, Hui; Liu, Yadong; Liu, Xufeng; Hu, Dewen

    2016-04-01

    With great progress of space navigation technology, it becomes possible to travel beyond Earth's gravity. So far, it remains unclear whether the human brain can function normally within an environment of microgravity and confinement. Particularly, it is a challenge to figure out some neuroimaging-based markers for rapid screening diagnosis of disrupted brain function in microgravity environment. In this study, a 7-day -6° head down tilt bed rest experiment was used to simulate the microgravity, and twenty healthy male participants underwent resting-state functional magnetic resonance imaging scans at baseline and after the simulated microgravity experiment. We used a multivariate pattern analysis approach to distinguish the brain states with simulated microgravity from normal gravity based on the functional connectivity within the default network, resulting in an accuracy of no less than 85 % via cross-validation. Moreover, most discriminative functional connections were mainly located between the limbic system and cortical areas and were enhanced after simulated microgravity, implying a self-adaption or compensatory enhancement to fulfill the need of complex demand in spatial navigation and motor control functions in microgravity environment. Overall, the findings suggest that the brain states in microgravity are likely different from those in normal gravity and that brain connectome could act as a biomarker to indicate the brain state in microgravity. PMID:27066149

  15. Platelet serotonin transporter function predicts default-mode network activity.

    Directory of Open Access Journals (Sweden)

    Christian Scharinger

    Full Text Available The serotonin transporter (5-HTT is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence.A functional magnetic resonance study was performed in 48 healthy subjects and maximal 5-HT uptake velocity (Vmax was assessed in blood platelets. We used a mixed-effects multilevel analysis technique (MEMA to test for linear relationships between whole-brain, blood-oxygen-level dependent (BOLD activity and platelet Vmax.The present study demonstrates that increases in platelet Vmax significantly predict default-mode network (DMN suppression in healthy subjects independent of genetic variation within SLC6A4. Furthermore, functional connectivity analyses indicate that platelet Vmax is related to global DMN activation and not intrinsic DMN connectivity.This study provides evidence that platelet Vmax predicts global DMN activation changes in healthy subjects. Given previous reports on platelet-synaptosomal Vmax coupling, results further suggest an important role of neuronal 5-HT reuptake in DMN regulation.

  16. Gamification of learning deactivates the Default Mode Network

    Directory of Open Access Journals (Sweden)

    Paul Alexander Howard-Jones

    2016-01-01

    Full Text Available We hypothesised that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN and deactivation of Default Mode Network (DMN regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer, Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards. DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated.

  17. Gamification of Learning Deactivates the Default Mode Network.

    Science.gov (United States)

    Howard-Jones, Paul A; Jay, Tim; Mason, Alice; Jones, Harvey

    2015-01-01

    We hypothesized that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN) and deactivation of default mode network (DMN) regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer), Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points) and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards). DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated. PMID:26779054

  18. Prediction of default probability in banking industry using CAMELS index: A case study of Iranian banks

    Directory of Open Access Journals (Sweden)

    Mohammad Khodaei Valahzaghard

    2013-04-01

    Full Text Available This study examines the relationship between CAMELS index and default probability among 20 Iranian banks. The proposed study gathers the necessary information from their financial statements over the period 2005-2011. The study uses logistic regression along with Pearson correlation analysis to consider the relationship between default probability and six independent variables including capital adequacy, asset quality, management quality, earning quality, liquidity quality and sensitivity of market risk. The results indicate that there were no meaningful relationship between default probability and three independent variables including capital adequacy, asset quality and sensitivity of market risk. However, the results of our statistical tests support such relationship between default probability and three other variables including management quality, earning quality and liquidity quality.

  19. Overpricing in Emerging Market Credit-Default-Swap Contracts; Some Evidence from Recent Distress Cases

    OpenAIRE

    Jochen R. Andritzky; Manmohan Singh

    2005-01-01

    Since recent debt restructurings that constitute credit events have been more frequent than outright defaults, sovereign bond prices may not collapse during distress. In this case, the likely high recovery values after restructuring suggest that the cost of credit-default-swap (CDS) contracts to the buyer (as measured by CDS spreads) may be higher than warranted. We estimate the extent of such overpricing by using the cheapest-to-deliver (CTD) bond as a proxy for the recovery-value assumption.

  20. Do corporate bond and credit default swap markets value environmental, social or corporate governance events?

    OpenAIRE

    Berg, Florian; Le Pen, Yannick

    2013-01-01

    We measure the impact of negative environmental, social and governance news on corporate bond prices and credit default swap premiums for the Eurozone market. Each firm is affected at least by one piece of news related to its environmental, social and governance practices. Each news is then flagged with an indicator of importance. Ab- normal bond returns are computed by subtracting return from a matching portfolio to the return of the observed bond return. Abnormal credit default swap return ...

  1. Predicting default of a small business using different definitions of financial distress

    OpenAIRE

    S-M Lin; Ansell, J; G Andreeva

    2012-01-01

    The paper introduces a number of risk-rating models for UK small businesses applying an accounting-based approach, which uses financial ratios to predict corporate bankruptcy. An enhancement to these models is considered through features typical to retail credit risk modelling. A common problem of default prediction consists in the relatively small number of bankruptcies or real defaults available for model-building. In order to expand the ‘default’ group beyond bankrupt companies, the paper ...

  2. Default and Renegotiation of Latin American Foreign Bonds in the Interwar Period

    OpenAIRE

    Erika Jorgensen; Jeffrey Sachs

    1988-01-01

    This paper examines the patterns of defaults, renegotiations, and final settlements on foreign borrowing of several Latin American governments in the interwar period. One goal of the paper is to provide a detailed historical account of the borrowing and renegotiation experience of five Latin borrowers (Argentina, Bolivia, Chile, Colombia, and Peru). Another goal is to provide a quantitative assessment of the amount of debt relief that was implicit in the negotiated settlements of the defaults...

  3. Loss Given Default - Modelle zur Schätzung von Recovery Rates

    OpenAIRE

    Böttger, Marc; Guthoff, Anja; Heidorn, Thomas

    2008-01-01

    Loss Given Default (LGD) is a major element for pricing credits and bonds. As there has been a substantial amount of research during the last years, this paper aims to give an overview. Initially, defaults and recovery definitions for credits and the differences to bonds are discussed. A survey of the empirical literature is given, finding average recovery rates for credits between 40% and 87% and lower rates for bonds. A survey of the literature on the influences on LGD showed 17 parameters....

  4. 34 CFR 33.10 - Default upon failure to file an answer.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Default upon failure to file an answer. 33.10 Section 33.10 Education Office of the Secretary, Department of Education PROGRAM FRAUD CIVIL REMEDIES ACT § 33.10 Default upon failure to file an answer. (a) If the defendant does not file an answer within the time prescribed in § 33.9(a), the...

  5. Abnormal functional connectivity of default mode sub-networks in autism spectrum disorder patients

    OpenAIRE

    Assaf, Michal; Jagannathan, Kanchana; Calhoun, Vince D.; Miller, Laura; Stevens, Michael C.; Sahl, Robert; O'Boyle, Jacqueline G.; Schultz, Robert T.; Godfrey D. Pearlson

    2010-01-01

    Autism spectrum disorders (ASDs) are characterized by deficits in social and communication processes. Recent data suggest that altered functional connectivity (FC), i.e. synchronous brain activity, might contribute to these deficits. Of specific interest is the FC integrity of the default mode network (DMN), a network active during passive resting states and cognitive processes related to social deficits seen in ASD, e.g. Theory of Mind. We investigated the role of altered FC of default mode ...

  6. The link between default and recovery rates: effects on the procyclicality of regulatory capital ratios

    OpenAIRE

    Edward I. Altman; Andrea Resti; Andrea Sironi

    2002-01-01

    This paper analyses the impact of various assumptions about the association between aggregate default probabilities and the loss given default on bank loans and corporate bonds, and seeks to empirically explain this critical relationship. Moreover, it simulates the effects of this relationship on the procyclicality of mandatory capital requirements like those proposed in 2001 by the Basel Committee on Banking Supervision. We present the analysis and results in four distinct sections. The firs...

  7. Evaluation of Hepatoprotective Effect of Silymarin Among Under Treatment Tuberculosis Patients: A Randomized Clinical Trial.

    Science.gov (United States)

    Marjani, Majid; Baghaei, Parvaneh; Kazempour Dizaji, Mehdi; Gorji Bayani, Pegah; Fahimi, Fanak; Tabarsi, Payam; Velayati, Ali Akbar

    2016-01-01

    Hepatic toxicity is the most serious adverse effect of anti-tuberculosis drugs. This study was performed to evaluate the efficacy of silymarin as a hepatoprotective herbal agent. In a randomized double blind clinical trial, 70 new cases of pulmonary tuberculosis were divided into two groups. The intervention group was assigned to receive silymarin and the control group received placebo. Tuberculosis was treated by classic regimen consisting isoniazid, rifampin, pyrazinamide and ethambutol. No statistically significant difference was found between the two groups concerning the frequency of drug induced liver injury or mild elevation of liver enzymes. Silymarin was safe without any major side effect. Our results showed no significant hepatoprotective effect of silymarin among patients on tuberculosis treatment. PMID:27610165

  8. Coding in pigeons: Multiple-coding versus single-code/default strategies.

    Science.gov (United States)

    Pinto, Carlos; Machado, Armando

    2015-05-01

    To investigate the coding strategies that pigeons may use in a temporal discrimination tasks, pigeons were trained on a matching-to-sample procedure with three sample durations (2s, 6s and 18s) and two comparisons (red and green hues). One comparison was correct following 2-s samples and the other was correct following both 6-s and 18-s samples. Tests were then run to contrast the predictions of two hypotheses concerning the pigeons' coding strategies, the multiple-coding and the single-code/default. According to the multiple-coding hypothesis, three response rules are acquired, one for each sample. According to the single-code/default hypothesis, only two response rules are acquired, one for the 2-s sample and a "default" rule for any other duration. In retention interval tests, pigeons preferred the "default" key, a result predicted by the single-code/default hypothesis. In no-sample tests, pigeons preferred the key associated with the 2-s sample, a result predicted by multiple-coding. Finally, in generalization tests, when the sample duration equaled 3.5s, the geometric mean of 2s and 6s, pigeons preferred the key associated with the 6-s and 18-s samples, a result predicted by the single-code/default hypothesis. The pattern of results suggests the need for models that take into account multiple sources of stimulus control. PMID:25894105

  9. Validation of the Merton Distance to the Default Model under Ambiguity

    Directory of Open Access Journals (Sweden)

    Wei-ling Chen

    2014-03-01

    Full Text Available Bharath and Shumway (2008 provide evidence that shows that it is the functional form of Merton’s (1974 distance to default (DD model that makes it useful and important for predicting defaults. In this paper, we investigate whether the default predictability of the Merton DD model would be affected by taking investors’ ambiguity aversion into consideration. The Cox proportional hazard model is used to compare the forecasting power of Bharath and Shumway’s naive model, which retains the functional form of the Merton DD model and computes the default probability in a naive way, with our new model, which treats investors’ ambiguity aversion as additional information. We provide evidence to show that our new model performs better than Bharath and Shumway’s naive model. In addition, our empirical results show that the statistical significance of Bharath and Shumway’s naive default probability is retained in the credit default swap (CDS spread regressions, though the sign of the coefficient is changed. However, both the sign and the statistical significance of our model are retained in the CDS spread regressions.

  10. Affective network and default mode network in depressive adolescents with disruptive behaviors

    Directory of Open Access Journals (Sweden)

    Kim SM

    2015-12-01

    Full Text Available Sun Mi Kim,1 Sung Yong Park,1 Young In Kim,1 Young Don Son,2 Un-Sun Chung,3,4 Kyung Joon Min,1 Doug Hyun Han1 1Department of Psychiatry, School of Medicine, Chung-Ang University, Seoul, 2Department of Biomedical Engineering, Gachon University of Medicine and Science, Incheon, 3Department of Psychiatry, School of Medicine, Kyungpook National University, 4School Mental Health Resources and Research Center, Kyungpook National University Children’s Hospital, Daegu, South Korea Aim: Disruptive behaviors are thought to affect the progress of major depressive disorder (MDD in adolescents. In resting-state functional connectivity (RSFC studies of MDD, the affective network (limbic network and the default mode network (DMN have garnered a great deal of interest. We aimed to investigate RSFC in a sample of treatment-naïve adolescents with MDD and disruptive behaviors.Methods: Twenty-two adolescents with MDD and disruptive behaviors (disrup-MDD and 20 age- and sex-matched healthy control (HC participants underwent resting-state functional magnetic resonance imaging (fMRI. We used a seed-based correlation approach concerning two brain circuits including the affective network and the DMN, with two seed regions ­including the bilateral amygdala for the limbic network and the bilateral posterior cingulate cortex (PCC for the DMN. We also observed a correlation between RSFC and severity of depressive symptoms and disruptive behaviors.Results: The disrup-MDD participants showed lower RSFC from the amygdala to the orbitofrontal cortex and parahippocampal gyrus compared to HC participants. Depression scores in disrup-MDD participants were negatively correlated with RSFC from the amygdala to the right orbitofrontal cortex. The disrup-MDD participants had higher PCC RSFC compared to HC participants in a cluster that included the left precentral gyrus, left insula, and left parietal lobe. Disruptive behavior scores in disrup-MDD patients were positively

  11. Acupuncture induce the different modulation patterns of the default mode network: an fMRI study

    Science.gov (United States)

    Liu, Peng; Qin, Wei; Tian, Jie; Zhang, Yi

    2009-02-01

    According to Traditional Chinese Medicine (TCM) theory and certain clinical treatment reports, the sustained effects of acupuncture indeed exist, which may last several minutes or hours. Furthermore, increased attention has fallen on the sustained effects of acupuncture. Recently, it is reported that the sustained acupuncture effects may alter the default mode network (DMN). It raises interesting questions: whether the modulations of acupuncture effects to the DMN are still detected at other acupoints and whether the modulation patterns are different induced by different acupoints. In the present study, we wanted to investigate the questions. An experiment fMRI design was carried out on 36 subjects with the electroacupuncture stimulation (EAS) at the three acupoints: Guangming (GB37), Kunlun (BL60) and Jiaoxin (KI8) on the left leg. The data sets were analyzed by a data driven method named independent component analysis (ICA). The results indicated that the three acupoints stimulations may modulate the DMN. Moreover, the modulation patterns were distinct. We suggest the different modulation patterns on the DMN may attribute to the distinct functional effects of acupoints.

  12. Chalcones and flavonoids as anti-tuberculosis agents.

    Science.gov (United States)

    Lin, Yuh-Meei; Zhou, Yasheen; Flavin, Michael T; Zhou, Li-Ming; Nie, Weiguo; Chen, Fa-Ching

    2002-08-01

    A series of flavonoids, chalcones and chalcone-like compounds were evaluated for inhibitory activity against Mycobacterium tuberculosis H37Rv. Among them, eight compounds exhibited >90% inhibition on the growth of the bacteria at a concentration of 12.5 microg/mL. Chalcones 1-(2-hydroxyphenyl)-3-(3-chlorophenyl)-2-propen-1-one (22) and 1-(2-hydroxyphenyl)-3-(3-iodophenyl)-2-propen-1-one (37) demonstrated 90 and 92% inhibition, respectively. Chalcone-like compounds (heterocyclic ring-substituted 2-propen-1-one) 1-(4-fluorophenyl)-3-(pyridin-3-yl)-2-propen-1-one (48), 1-(3-hydroxyphenyl)-3-(phenanthren-9-yl)-2-propen-1-one (49), 1-(pyridin-3-yl)-3-(phenanthen-9-yl)-2-propen-1-one (50) and 1-(furan-2-yl)-3-phenyl-2-propen-1-one (51) exhibited 98, 97, 96 and 96% inhibition, respectively. The actual minimum inhibitory concentrations (MIC), defined as the lowest concentration inhibiting 99% of the inoculum, for 22, 37, 48, 49, 50 and 51 were 20.3, 31.5, 48.3, >35.7, 6.8 and 19.2, respectively. A hydrophobic substituent on one aromatic ring, and a hydrogen-bonding group on the other aromatic ring resulted in increased anti-TB activity of the chalcones and chalcone-like compounds. Flavones and flavanones are more geometrically constrained than the corresponding chalcone analogues. The decreased activity of the flavones with respect to the chalcones may be due to the confinement of the terminal aromatic rings to the same plane. PMID:12057669

  13. Combined antiretroviral and anti-tuberculosis drug resistance following incarceration

    OpenAIRE

    Stott, K E; de Oliviera, T; Lessells, R.J.

    2013-01-01

    We describe a case of HIV/tuberculosis (TB) co-infection from KwaZulu-Natal, South Africa, characterised by drug resistance in both pathogens. The development of drug resistance was linked temporally to two periods of incarceration. This highlights the urgent need for improved integration of HIV/TB control strategies within prison health systems and within the broader public health framework.

  14. Implementation and outcomes of an active defaulter tracing system for HIV, prevention of mother to child transmission of HIV (PMTCT), and TB patients in Kibera, Nairobi, Kenya.

    OpenAIRE

    Thomson, Kerry A.; Cheti, Erastus O; Reid, Tony

    2011-01-01

    Retention of patients in long term care and adherence to treatment regimens are a constant challenge for HIV, prevention of mother to child transmission of HIV (PMTCT), and TB programmes in sub-Saharan Africa. This study describes the implementation and outcomes of an active defaulter tracing system used to reduce loss to follow-up (LTFU) among HIV, PMTCT, TB, and HIV/TB co-infected patients receiving treatment at three Médecins Sans Frontières clinics in the informal settlement of Kibera, Na...

  15. EEG PHASE RESET OF THE DEFAULT MODE NETWORK

    Directory of Open Access Journals (Sweden)

    Robert W. Thatcher

    2014-07-01

    Full Text Available Objectives: The purpose of this study was to explore phase reset of 3-dimensional current sources located in Brodmann areas located in the human default mode network (DMN using Low Resolution Electromagnetic Tomography (LORETA of the human electroencephalogram (EEG. Methods: The EEG was recorded from 19 scalp locations from 70 healthy normal subjects ranging in age from 13 to 20 years. A time point by time point computation of LORETA current sources were computed for 14 Brodman areas comprising the DMN in the delta frequency band. The Hilbert transform of the LORETA time series was used to compute the instantaneous phase differences between all pairs of Brodmann areas. Phase shift and lock durations were calculated based on the 1st & 2nd derivatives of the time series of phase differences. Results: Phase shift duration exhibited three discrete modes at approximately: 1- 30 msec,, 2- 55 msec and, 3- 65 msec. Phase lock duration present primarily at: 1- 300 to 350 msec and, 2- 350 msec to 450 msec. Phase shift and lock durations were inversely related and exhibited an exponential change with distance between Brodmann areas. Conclusions: The results are explained by local neural packing density of network hubs and an exponential decrease in connections with distance from a hub. The results are consistent with a discrete temporal model of brain function where anatomical hubs behave like a ‘shutter’ that opens and closes at specific durations as nodes of a network giving rise to temporarily phase locked clusters of neurons for specific durations.

  16. Structural covariance of the default network in healthy and pathological aging.

    Science.gov (United States)

    Spreng, R Nathan; Turner, Gary R

    2013-09-18

    Significant progress has been made uncovering functional brain networks, yet little is known about the corresponding structural covariance networks. The default network's functional architecture has been shown to change over the course of healthy and pathological aging. We examined cross-sectional and longitudinal datasets to reveal the structural covariance of the human default network across the adult lifespan and through the progression of Alzheimer's disease (AD). We used a novel approach to identify the structural covariance of the default network and derive individual participant scores that reflect the covariance pattern in each brain image. A seed-based multivariate analysis was conducted on structural images in the cross-sectional OASIS (N = 414) and longitudinal Alzheimer's Disease Neuroimaging Initiative (N = 434) datasets. We reproduced the distributed topology of the default network, based on a posterior cingulate cortex seed, consistent with prior reports of this intrinsic connectivity network. Structural covariance of the default network scores declined in healthy and pathological aging. Decline was greatest in the AD cohort and in those who progressed from mild cognitive impairment to AD. Structural covariance of the default network scores were positively associated with general cognitive status, reduced in APOEε4 carriers versus noncarriers, and associated with CSF biomarkers of AD. These findings identify the structural covariance of the default network and characterize changes to the network's gray matter integrity across the lifespan and through the progression of AD. The findings provide evidence for the large-scale network model of neurodegenerative disease, in which neurodegeneration spreads through intrinsically connected brain networks in a disease specific manner. PMID:24048852

  17. Measurement, Monitoring, and Forecasting of Consumer Credit Default Risk - An Indicator Approach Based on Individual Payment Histories

    OpenAIRE

    Schwarz, Alexandra

    2011-01-01

    The statistical techniques which cover the process of modeling and evaluating consumer credit risk have become widely accepted instruments in risk management. In contrast, we find only few and vague statements on how to define the default event, i. e. on the concrete circumstances that lead to the decision of identifying a certain credit as defaulted. Based on a unique data set of individual payment histories this paper proposes a definition of default which is based on the time due amounts a...

  18. Effect of standard tuberculosis treatment on naive, memory and regulatory T-cell homeostasis in tuberculosis-diabetes co-morbidity.

    Science.gov (United States)

    Kumar, Nathella P; Moideen, Kadar; Viswanathan, Vijay; Kornfeld, Hardy; Babu, Subash

    2016-09-01

    Perturbations in CD4(+) and CD8(+) T-cell phenotype and function are hallmarks of tuberculosis-diabetes co-morbidity. However, their contribution to the pathogenesis of this co-morbidity and the effect of anti-tuberculosis treatment on the phenotype of the T-cell subsets is poorly understood. In this study, we examined the frequency of different T-cell subsets in individuals with pulmonary tuberculosis (PTB) with diabetes mellitus (DM) or without coincident diabetes mellitus (NDM) before, during and after completion of anti-tuberculosis chemotherapy. PTB-DM is characterized by heightened frequencies of central memory CD4(+) and CD8(+) T cells and diminished frequencies of naive, effector memory and/or effector CD4(+) and CD8(+) T cells at baseline and after 2 months of treatment but not following treatment completion in comparison with PTB-NDM. Central memory CD4(+) and CD8(+) T-cell frequencies exhibited a positive correlation with fasting blood glucose and glycated haemoglobin A1c levels, whereas the frequencies of naive and effector memory or effector CD4(+) and CD8(+) T cells exhibited a negative correlation. However, the frequencies of CD4(+) and CD8(+) T-cell subsets in individuals with PTB exhibited no significant relationship with bacterial burdens. Finally, although minor alterations in the T-cell subset compartment were observed at 2 months of treatment, significantly decreased frequencies of central memory and significantly enhanced frequencies of naive CD4(+) and CD8(+) T cells were observed at the completion of treatment. Our data reveal a profound effect of coexistent diabetes on the altered frequencies of central memory, effector memory and naive T cells and its normalization following therapy. PMID:27289086

  19. Interactions between default mode and control networks as a function of increasing cognitive reasoning complexity.

    Science.gov (United States)

    Hearne, Luke; Cocchi, Luca; Zalesky, Andrew; Mattingley, Jason B

    2015-07-01

    Successful performance of challenging cognitive tasks depends on a consistent functional segregation of activity within the default-mode network, on the one hand, and control networks encompassing frontoparietal and cingulo-opercular areas on the other. Recent work, however, has suggested that in some cognitive control contexts nodes within the default-mode and control networks may actually cooperate to achieve optimal task performance. Here, we used functional magnetic resonance imaging to examine whether the ability to relate variables while solving a cognitive reasoning problem involves transient increases in connectivity between default-mode and control regions. Participants performed a modified version of the classic Wason selection task, in which the number of variables to be related is systematically varied across trials. As expected, areas within the default-mode network showed a parametric deactivation with increases in relational complexity, compared with neural activity in null trials. Critically, some of these areas also showed enhanced connectivity with task-positive control regions. Specifically, task-based connectivity between the striatum and the angular gyri, and between the thalamus and right temporal pole, increased as a function of relational complexity. These findings challenge the notion that functional segregation between regions within default-mode and control networks invariably support cognitive task performance, and reveal previously unknown roles for the striatum and thalamus in managing network dynamics during cognitive reasoning. PMID:25833189

  20. Framework of pricing a revolver loan in the case of dependent defaults

    Institute of Scientific and Technical Information of China (English)

    ZHAN Yuan-rui; YAO Xiang-hua; ZHANG Xue-yu

    2006-01-01

    In this paper we analyze the main characteristics of correlative clients and the revolver loan and reduced form models for the correlative clients A and B in real-life. This is done by decomposing the default intensity into specific default intensity and homogenous default intensity. We also use a mathematical formula of the default joint distribution function and the marginal distribution function in the physical measure to deduce the martingale measure. The modeling idea on pricing the revolver loan with client A is presented by applying reduced form model. Through calculating the cost and income fund flows under the martingale measure, the framework of a "break-even" pricing model is established. The conclusion is that the interest rate of a revolver loan for client A on the "break-even" point is not related to the maximum authorized amount and the drawdown amount at that time under some assumptions, but only rests with credit rating and homogenous default intensity of client A and B as well as loan term of client A.

  1. Assessing Credit Default using Logistic Regression and Multiple Discriminant Analysis: Empirical Evidence from Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Deni Memić

    2015-01-01

    Full Text Available This article has an aim to assess credit default prediction on the banking market in Bosnia and Herzegovina nationwide as well as on its constitutional entities (Federation of Bosnia and Herzegovina and Republika Srpska. Ability to classify companies info different predefined groups or finding an appropriate tool which would replace human assessment in classifying companies into good and bad buckets has been one of the main interests on risk management researchers for a long time. We investigated the possibility and accuracy of default prediction using traditional statistical methods logistic regression (logit and multiple discriminant analysis (MDA and compared their predictive abilities. The results show that the created models have high predictive ability. For logit models, some variables are more influential on the default prediction than the others. Return on assets (ROA is statistically significant in all four periods prior to default, having very high regression coefficients, or high impact on the model's ability to predict default. Similar results are obtained for MDA models. It is also found that predictive ability differs between logistic regression and multiple discriminant analysis.

  2. Default network connectivity reflects the level of consciousness in non-communicative brain-damaged patients.

    Science.gov (United States)

    Vanhaudenhuyse, Audrey; Noirhomme, Quentin; Tshibanda, Luaba J-F; Bruno, Marie-Aurelie; Boveroux, Pierre; Schnakers, Caroline; Soddu, Andrea; Perlbarg, Vincent; Ledoux, Didier; Brichant, Jean-François; Moonen, Gustave; Maquet, Pierre; Greicius, Michael D; Laureys, Steven; Boly, Melanie

    2010-01-01

    The 'default network' is defined as a set of areas, encompassing posterior-cingulate/precuneus, anterior cingulate/mesiofrontal cortex and temporo-parietal junctions, that show more activity at rest than during attention-demanding tasks. Recent studies have shown that it is possible to reliably identify this network in the absence of any task, by resting state functional magnetic resonance imaging connectivity analyses in healthy volunteers. However, the functional significance of these spontaneous brain activity fluctuations remains unclear. The aim of this study was to test if the integrity of this resting-state connectivity pattern in the default network would differ in different pathological alterations of consciousness. Fourteen non-communicative brain-damaged patients and 14 healthy controls participated in the study. Connectivity was investigated using probabilistic independent component analysis, and an automated template-matching component selection approach. Connectivity in all default network areas was found to be negatively correlated with the degree of clinical consciousness impairment, ranging from healthy controls and locked-in syndrome to minimally conscious, vegetative then coma patients. Furthermore, precuneus connectivity was found to be significantly stronger in minimally conscious patients as compared with unconscious patients. Locked-in syndrome patient's default network connectivity was not significantly different from controls. Our results show that default network connectivity is decreased in severely brain-damaged patients, in proportion to their degree of consciousness impairment. Future prospective studies in a larger patient population are needed in order to evaluate the prognostic value of the presented methodology. PMID:20034928

  3. Contribution of computed tomography guided percutaneous drainage of tuberculous cold abscesses adjunctive to pharmaceutical anti-tubercular treatment

    International Nuclear Information System (INIS)

    Purpose: To determine the efficiency and safety of the percutaneous aspiration and drainage of rare touberculous cold abscesses under CT guidance. Materials and methods: We retrospectively studied 63 cases of 44 patients, treated in our hospital during the last two years. They suffered from tuberculous infection complicated with tuberculous cold abscesses variously located. All these patients underwent percutaneous aspiration and drainage under CT imaging, following the trocar puncture technique. The catheter remained in place for about a week. A follow up CT scan was performed in all cases before the catheter removal. Some of the patients were under anti tuberculosis medication. Results: All the patients had a successful recovery from the abscesses. There were no major or minor complications observed. No recurrence occurred until today. Conclusion: CT guided percutaneous aspiration and drainage of tuberculous cold abscesses is a safe, minimal invasive and effective method of treatment. Drainage and specific antituberculosis therapy leads to a satisfactory conclusion.

  4. Towards an Understanding of the Effects of IFRS Adoption on Credit Default Swap Contracts

    Directory of Open Access Journals (Sweden)

    Trent W. Batchelor

    2016-01-01

    Full Text Available This essay evaluates the impact of the International Financial Reporting Standards on the pricing of the credit default swap (CDS market. The purpose extended to application of the evaluation synthesized into a best-fit strategy for participants of the CDS market as designated the buyers, and sellers. The impact of IFRS 9 on the pricing of the CDS market, using an event study method, integrates into an accounting strategy allowing the seller of protection to reduce asset value instead of creating revenue on an uncertain financial asset. The results of the study first that regulation has an effect on notional prices of credit default swaps and second that cumulative abnormal return exists in the financial sector as compared to the CDS market. A best-fit strategy for buyers and sellers of protection using derivatives known as credit default swaps in an attempt to exercise the inefficiencies created by the pricing of the CDS derivative instruments.

  5. Default Rate and Price of Capital in a Costly External Finance Model

    Directory of Open Access Journals (Sweden)

    Juan Pablo Medina

    2006-03-01

    Full Text Available Financial frictions have been used to enrich mechanisms transmission in macroeconomics. However, the predictions of real business cycle models of costly external finance imply a procyclical default rate, external premium and relative price of capital which seems at odds with the data. In this article, we include technology shocks that affect the average productivity and idiosyncratic risk of capital producers in a standard costly external finance model. These elements enhance the model to deliver a countercyclical default rate, external finance and relative price of capital premium which are more consistent with the data and contrary to the results obtained with a sector-neutral productivity shock. Intuitively, if the entrepreneurs’ investment projects become more productive in average, the relative price of capital and the default rate fall while investment and output increase. Using data on the relative price of capital, we perform a calibration of this type of shocks which highlights its business-cycle relevance.

  6. q-Gaussian distributions of leverage returns, first stopping times, and default risk valuations

    Science.gov (United States)

    Katz, Yuri A.; Tian, Li

    2013-10-01

    We study the probability distributions of daily leverage returns of 520 North American industrial companies that survive de-listing during the financial crisis, 2006-2012. We provide evidence that distributions of unbiased leverage returns of all individual firms belong to the class of q-Gaussian distributions with the Tsallis entropic parameter within the interval 1Motivated by these findings, we develop a q-Gaussian generalization of traditional structural models of default. Derived exact analytical expressions for the probability distribution of a first stopping time and its intensity forecast significantly higher probability of default and much wider credit spreads at short time-horizons. Our findings are broadly consistent with the results of empirical studies in equity markets and are essential for single-name default forecasting as well as valuations of portfolio credit risk and economic capital, which might be underestimated by a classic theory of diversified portfolio optimization.

  7. An Empirical Analysis of the Default Rate of Informal Lending—Evidence from Yiwu, China

    Science.gov (United States)

    Lu, Wei; Yu, Xiaobo; Du, Juan; Ji, Feng

    This study empirically analyzes the underlying factors contributing to the default rate of informal lending. This paper adopts snowball sampling interview to collect data and uses the logistic regression model to explore the specific factors. The results of these analyses validate the explanation of how the informal lending differs from the commercial loan. Factors that contribute to the default rate have particular attributes, while sharing some similarities with commercial bank or FICO credit scoring Index. Finally, our concluding remarks draw some inferences from empirical analysis and speculate as to what this may imply for the role of formal and informal financial sectors.

  8. Default positions : how neuroscience’s historical legacy has hampered investigation of the resting mind.

    OpenAIRE

    DanielSMargulies; FelicityCallard; JonathanSmallwood

    2012-01-01

    The puzzle of the brain and mind at rest – their so-called default state – is strongly influenced by the historical precedents that led to its emergence as a scientific question. What eventually became the default mode network (DMN) was inaugurated via meta-analysis to explain the observation that the baseline “at rest” condition was concealing a pattern of neural activations in anterior and posterior midline brain regions that were not commonly seen in external, task-driven experiments. On...

  9. A Non-Gaussian Panel Time Series Model for Estimating and Decomposing Default Risk

    OpenAIRE

    Koopman, S.J.; Lucas, A.; Daniels, R

    2005-01-01

    This discussion paper led to an article in the Journal of Business and Economic Statistics (2008). Vol. 26, issue 4, pages 510-525. We model 1981–2002 annual US default frequencies for a panel of firms in different rating and age classes. The data is decomposed into a systematic and firm-specific risk component, where the systematic component reflects the general economic conditions and default climate. We have to cope with (i) the shared exposure of each age cohort and rating class to the sa...

  10. HIERtalker: A default hierarchy of high order neural networks that learns to read English aloud

    Energy Technology Data Exchange (ETDEWEB)

    An, Z.G.; Mniszewski, S.M.; Lee, Y.C.; Papcun, G.; Doolen, G.D.

    1988-01-01

    A new learning algorithm based on a default hierarchy of high order neural networks has been developed that is able to generalize as well as handle exceptions. It learns the ''building blocks'' or clusters of symbols in a stream that appear repeatedly and convey certain messages. The default hierarchy prevents a combinatoric explosion of rules. A simulator of such a hierarchy, HIERtalker, has been applied to the conversion of English words to phonemes. Achieved accuracy is 99% for trained words and ranges from 76% to 96% for sets of new words. 8 refs., 4 figs., 1 tab.

  11. A Multi-industry Default Prediction Model using Logistic Regression and Decision Tree

    Directory of Open Access Journals (Sweden)

    Suresh Ramakrishnan

    2015-04-01

    Full Text Available The accurate prediction of corporate bankruptcy for the firms in different industries is of a great concern to investors and creditors, as the reduction of creditors’ risk and a considerable amount of saving for an industry economy can be possible. Financial statements vary between industries. Therefore, economic intuition suggests that industry effects should be an important component in bankruptcy prediction. This study attempts to detail the characteristics of each industry using sector indicators. The results show significant relationship between probability of default and sector indicators. The results of this study may improve the default prediction models performance and reduce the costs of risk management.

  12. A General Scheme for Formalizing Defaults Using the Predicate ab(I,S)

    Institute of Scientific and Technical Information of China (English)

    SHEN Yidong

    1999-01-01

    In common sense reasoning two typical types of defaultsare encountered. One is of the form "All birds can fly except b1,b2,..., and bm (m1)", and the other "All birds can fly,but there exist exceptions". The first type of defaults is readilyformalized but the other, as some researchers have noticed, is difficultto deal with. This paper establishes a general scheme for formalizing defaults of the two types, the key to which is the introduction of atwo-argument predicate ab (I, S) to represent exceptional objects.

  13. SU-E-J-36: Comparison of CBCT Image Quality for Manufacturer Default Imaging Modes

    International Nuclear Information System (INIS)

    Purpose CBCT is being increasingly used in patient setup for radiotherapy. Often the manufacturer default scan modes are used for performing these CBCT scans with the assumption that they are the best options. To quantitatively assess the image quality of these scan modes, all of the scan modes were tested as well as options with the reconstruction algorithm. Methods A CatPhan 504 phantom was scanned on a TrueBeam Linear Accelerator using the manufacturer scan modes (FSRT Head, Head, Image Gently, Pelvis, Pelvis Obese, Spotlight, & Thorax). The Head mode scan was then reconstructed multiple times with all filter options (Smooth, Standard, Sharp, & Ultra Sharp) and all Ring Suppression options (Disabled, Weak, Medium, & Strong). An open source ImageJ tool was created for analyzing the CatPhan 504 images. Results The MTF curve was primarily dictated by the voxel size and the filter used in the reconstruction algorithm. The filters also impact the image noise. The CNR was worst for the Image Gently mode, followed by FSRT Head and Head. The sharper the filter, the worse the CNR. HU varied significantly between scan modes. Pelvis Obese had lower than expected HU values than most while the Image Gently mode had higher than expected HU values. If a therapist tried to use preset window and level settings, they would not show the desired tissue for some scan modes. Conclusion Knowing the image quality of the set scan modes, will enable users to better optimize their setup CBCT. Evaluation of the scan mode image quality could improve setup efficiency and lead to better treatment outcomes

  14. Aberrant functional connectivity of default-mode network in type 2 diabetes patients

    International Nuclear Information System (INIS)

    Type 2 diabetes mellitus is associated with increased risk for dementia. Patients with impaired cognition often show default-mode network disruption. We aimed to investigate the integrity of a default-mode network in diabetic patients by using independent component analysis, and to explore the relationship between network abnormalities, neurocognitive performance and diabetic variables. Forty-two patients with type 2 diabetes and 42 well-matched healthy controls were included and underwent resting-state functional MRI in a 3 Tesla unit. Independent component analysis was adopted to extract the default-mode network, including its anterior and posterior components. Z-maps of both sub-networks were compared between the two groups and correlated with each clinical variable. Patients showed increased connectivity around the medial prefrontal cortex in the anterior sub-network, but decreased connectivity around the posterior cingulate cortex in the posterior sub-network. The decreased connectivity in the posterior part was significantly correlated with the score on Complex Figure Test-delay recall test (r = 0.359, p = 0.020), the time spent on Trail-Making Test-part B (r = -0.346, p = 0.025) and the insulin resistance level (r = -0.404, p = 0.024). Dissociation pattern in the default-mode network was found in diabetic patients, which might provide powerful new insights into the neural mechanisms that underlie the diabetes-related cognitive decline. (orig.)

  15. 7 CFR 1493.500 - Notice of default and claims for loss.

    Science.gov (United States)

    2010-01-01

    ... importer obligation; (ii) Depending upon the method of shipment, the negotiable ocean carrier or intermodal..., FOB, CFR or CIF values; or (B) If there was an intervening purchaser, both the exporter's invoice to... obligation, the exporter or the exporter's assignee must submit a notice of default to CCC as soon...

  16. Default Path and Dedicated Path: A New Approach to Realize IP Directly Over WDM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Combining IP and WDM is an attractive direction for research. Instead the point to point linking method, this paper proposes a new approach to realize IP directly over WDM, called DPDP (default path and dedicated path), presents a conceivable architecture in detail and explains its working procedure. A lot of problems related with this design are also discussed.

  17. Liquidity crisis detection: An application of log-periodic power law structures to default prediction

    Science.gov (United States)

    Wosnitza, Jan Henrik; Denz, Cornelia

    2013-09-01

    We employ the log-periodic power law (LPPL) to analyze the late-2000 financial crisis from the perspective of critical phenomena. The main purpose of this study is to examine whether LPPL structures in the development of credit default swap (CDS) spreads can be used for default classification. Based on the different triggers of Bear Stearns’ near bankruptcy during the late-2000 financial crisis and Ford’s insolvency in 2009, this study provides a quantitative description of the mechanism behind bank runs. We apply the Johansen-Ledoit-Sornette (JLS) positive feedback model to explain the rise of financial institutions’ CDS spreads during the global financial crisis 2007-2009. This investigation is based on CDS spreads of 40 major banks over the period from June 2007 to April 2009 which includes a significant CDS spread increase. The qualitative data analysis indicates that the CDS spread variations have followed LPPL patterns during the global financial crisis. Furthermore, the univariate classification performances of seven LPPL parameters as default indicators are measured by Mann-Whitney U tests. The present study supports the hypothesis that discrete scale-invariance governs the dynamics of financial markets and suggests the application of new and fast updateable default indicators to capture the buildup of long-range correlations between creditors.

  18. Aberrant functional connectivity of default-mode network in type 2 diabetes patients

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ying; Jiao, Yun; Chen, Hua-Jun; Ding, Jie; Luo, Bing; Peng, Cheng-Yu; Ju, Sheng-Hong; Teng, Gao-Jun [Medical School of Southeast University, Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Nanjing, Jiangsu (China)

    2015-11-15

    Type 2 diabetes mellitus is associated with increased risk for dementia. Patients with impaired cognition often show default-mode network disruption. We aimed to investigate the integrity of a default-mode network in diabetic patients by using independent component analysis, and to explore the relationship between network abnormalities, neurocognitive performance and diabetic variables. Forty-two patients with type 2 diabetes and 42 well-matched healthy controls were included and underwent resting-state functional MRI in a 3 Tesla unit. Independent component analysis was adopted to extract the default-mode network, including its anterior and posterior components. Z-maps of both sub-networks were compared between the two groups and correlated with each clinical variable. Patients showed increased connectivity around the medial prefrontal cortex in the anterior sub-network, but decreased connectivity around the posterior cingulate cortex in the posterior sub-network. The decreased connectivity in the posterior part was significantly correlated with the score on Complex Figure Test-delay recall test (r = 0.359, p = 0.020), the time spent on Trail-Making Test-part B (r = -0.346, p = 0.025) and the insulin resistance level (r = -0.404, p = 0.024). Dissociation pattern in the default-mode network was found in diabetic patients, which might provide powerful new insights into the neural mechanisms that underlie the diabetes-related cognitive decline. (orig.)

  19. A Special Report on the Alaska Commission on Postsecondary Education--Collection of Defaulted Student Loans.

    Science.gov (United States)

    Welker, Randy S.

    In accordance with a Legislative Budget and Audit Committee special request and the provisions of Title 24 of the Alaska Statutes, a review was conducted of the Alaska Commission on Postsecondary Education's experience with various collection contractors used to collect defaulted student loans. The primary purpose was to assess the success that…

  20. 75 FR 32306 - Perishable Agricultural Commodities Act: Impact of Post-Default Agreements on Trust Protection...

    Science.gov (United States)

    2010-06-08

    ... the regulations under the Perishable Agricultural Commodities Act (PACA) in response to concerns... rule. Additional Information or Comments: You may submit written or electronic comments to PACA Trust Post-Default Comments, AMS, F&V Programs, PACA Branch, 1400 Independence Avenue SW., Room 2095-S,...

  1. 75 FR 51693 - Perishable Agricultural Commodities Act: Impact of Post-Default Agreements on Trust Protection...

    Science.gov (United States)

    2010-08-23

    ... published on June 8, 2010 (75 FR 32306). The proposed amendment to the regulations under the Perishable Agricultural Commodities Act (PACA) would allow a seller, supplier, or agent who has met the eligibility... comments to PACA Trust Post-Default Comments, AMS, F&V Programs, PACA Branch, 1400 Independence Avenue,...

  2. 29 CFR 2550.404c-5 - Fiduciary relief for investments in qualified default investment alternatives.

    Science.gov (United States)

    2010-07-01

    ...; provide a rate of return generally consistent with that earned on intermediate investment grade bonds; and... plan offers a “broad range of investment alternatives” within the meaning of 29 CFR 2550.404c-1(b)(3... default investment alternative, including a description of the investment objectives, risk and...

  3. Altered default mode network activity in patient with anxiety disorders: An fMRI study

    International Nuclear Information System (INIS)

    Anxiety disorder, a common mental disorder in our clinical practice, is characterized by unprovoked anxiety. Medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC), which closely involved in emotional processing, are critical regions in the default mode network. We used functional magnetic resonance imaging (fMRI) to investigate whether default mode network activity is altered in patients with anxiety disorder. Ten anxiety patients and 10 healthy controls underwent fMRI while listening to emotionally neutral words alternating with rest (Experiment 1) and threat-related words alternating with emotionally neutral words (Experiment 2). In Experiment 1, regions of deactivation were observed in patients and controls. In Experiment 2, regions of deactivation were observed only in patients. The observed deactivation patterns in the two experiments, which included MPFC, PCC, and inferior parietal cortex, were similar and consistent with the default model network. Less deactivation in MPFC and greater deactivation in PCC were observed for patients group comparing to controls in Experiment 1. Our observations suggest that the default model network is altered in anxiety patients and dysfunction in MPFC and PCC may play an important role in anxiety psychopathology

  4. Credit Default and Business Cycles: An Empirical Investigation of Brazilian Retail Loans

    Directory of Open Access Journals (Sweden)

    Arnildo da Silva Correa

    2014-09-01

    Full Text Available We use microdata from the Credit Information System (SCR of the Central Bank of Brazil to study the relationship between credit default and business cycles. In particular, we study the first part of the argument underlying the discussion about procyclicality related to the Basel II Accord: that recessions might increase credit defaults and have adverse impacts on the losses in portfolios of lender institutions. We explore both time series and cross-sectional variation in the data. Our data on the individual level are composed of retail loan transactions in two modalities-Consumer Credit and Vehicle Financing-from 2003 to 2008. Our results support the idea of a negative relationship between business cycles and credit default, but less strong than suggested in previous studies that use corporate data. We also find low and dispersed default correlations, and smaller losses in Value at Risk (VaR experiments than those found in the literature. These results may be possibly explained by the fact that, in the retail sector, loans are given to a large number of individuals, which may help to diversify risks.

  5. Flu and Finances: Influenza Outbreaks and Loan Defaults in US Cities, 2004–2012

    Science.gov (United States)

    Collins, J. Michael; Schmeiser, Maximilian D.

    2015-01-01

    Objectives. We examined the association between influenza outbreaks in 83 metropolitan areas and credit card and mortgage defaults, as measured in quarterly zip code–level credit data over the period of 2004 to 2012. Methods. We used ordinary least squares, fixed effects, and 2-stage least squares instrumental variables regression strategies to examine the relationship between influenza-related Google searches and 30-, 60-, and 90-day credit card and mortgage delinquency rates. Results. We found that a proxy for influenza outbreaks is associated with a small but statistically significant increase in credit card and mortgage default rates, net of other factors. These effects are largest for 90-day defaults, suggesting that influenza outbreaks have a disproportionate impact on vulnerable borrowers who are already behind on their payments. Conclusions. Overall, it appears there is a relationship between exogenous health shocks (such as influenza) and credit default. The results suggest that consumer finances could benefit from policies that aim to reduce the financial shocks of illness, particularly for vulnerable borrowers. PMID:26180971

  6. Pricing model of credit default swap with stochastic foreign exchange rate

    Directory of Open Access Journals (Sweden)

    WANG Yang

    2013-04-01

    Full Text Available A pricing model is established by using the structure approach and the backward Kolmogrov equation under the assumption of stochastic foreign exchange rate.The explicit solution of credit default swap is obtained for the dollar market.And a correlative financial analysis is given.

  7. Altered default mode network activity in patient with anxiety disorders: An fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Xiaohu [Imaging Department of Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China) and Bio-X lab, Department of Physics, Zhe Jiang University, Hangzhou 310027 (China)], E-mail: xhzhao999@263.net; Wang Peijun [Imaging Department of Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: tongjipjwang@vip.sina.com; Li Chunbo [Department of Psychiatry, Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: licb@mail.tongji.edu.cn; Hu Zhenghui [Department of Electrical and Engineering, Hong Kong University of Science and Technology, Hong Kong (China)], E-mail: eezhhu@ust.hk; Xi Qian [Imaging Department of Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: 96125007@sina.com.cn; Wu Wenyuan [Department of Psychiatry, Tong Ji Hospital of Tong Ji University, Shanghai 200065 (China)], E-mail: wuwy@mail.tongji.edu.cn; Tang Xiaowei [Bio-X lab, Department of Physics, Zhe Jiang University, Hangzhou 310027 (China)], E-mail: tangxw@zju.edu.cn

    2007-09-15

    Anxiety disorder, a common mental disorder in our clinical practice, is characterized by unprovoked anxiety. Medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC), which closely involved in emotional processing, are critical regions in the default mode network. We used functional magnetic resonance imaging (fMRI) to investigate whether default mode network activity is altered in patients with anxiety disorder. Ten anxiety patients and 10 healthy controls underwent fMRI while listening to emotionally neutral words alternating with rest (Experiment 1) and threat-related words alternating with emotionally neutral words (Experiment 2). In Experiment 1, regions of deactivation were observed in patients and controls. In Experiment 2, regions of deactivation were observed only in patients. The observed deactivation patterns in the two experiments, which included MPFC, PCC, and inferior parietal cortex, were similar and consistent with the default model network. Less deactivation in MPFC and greater deactivation in PCC were observed for patients group comparing to controls in Experiment 1. Our observations suggest that the default model network is altered in anxiety patients and dysfunction in MPFC and PCC may play an important role in anxiety psychopathology.

  8. Default risk, bankruptcy procedures and the market value of life insurance liabilities

    NARCIS (Netherlands)

    A. Chen; M. Suchanecki

    2007-01-01

    The topic of insolvency risk in connection with life insurance companies has recently attracted a great deal of attention. In this paper, the question is investigated of how the values of the equity and of the liability of a life insurance company are affected by the default risk and the choice of t

  9. Bar Admission--Default on Student Loan Warrants Denial of Admission to Minnesota Bar.

    Science.gov (United States)

    William Mitchell Law Review, 1980

    1980-01-01

    The Minnesota Supreme Court upheld a decision that student loan default, and subsequent dismissal through bankruptcy, is sufficient reason to deny a law student's bar admission. The bar's requirement of good moral character was interpreted as financial integrity in the Gahan case. (MSE)

  10. Automatic for the Borrower: How Repayment Based on Income Can Reduce Loan Defaults and Manage Risk

    Science.gov (United States)

    Baum, Sandy; Carew, Diana; Fraire, Jacob; Jacks, Kay; James, Kevin; Madzelan, Daniel; Miller, Scott E.; Simmons, Barry; Thompson, Jessica

    2014-01-01

    When borrowers default on a federal student loan, it can have catastrophic consequences. Their credit scores drop dramatically, severely curtailing their ability to afford a home or a car, and even limiting their ability to sign up for utilities. The cost of their loan rises as late fees pile up. Moreover, the federal government can garnish…

  11. THE RELATIONSHIP BETWEEN MACROECONOMIC VARIABLES AND ROMANIAN CORPORATE DEFAULT RATES BETWEEN 2002-2008

    Directory of Open Access Journals (Sweden)

    Suveg Orsolya

    2011-07-01

    Full Text Available During its 20 year history of market economy, Romania experienced the most severe downturn in 2009, which resulted in many cost, mainly because of the output loss. These conditions forced several firms to declare bankruptcy and to stop their activity. The aim of this research is to assess the relationship between the corporate default rates and the macroeconomic processes in the case of Romania for the period comprised between 2002Q1-2008Q4. For this, based on the relevant literature, we ranked the potential explanatory variables of the default rates into seven groups: cyclical indicators, household indicators, corporate indicators, external sector indicators, price stability indicators and interest rates, loans to private sector and finally the capital market indicators. Some studies base their results only on accounting data, others only on market data. Our study focuses on both, since this seems to be an adequate approach in capturing most of the processes. Similar to the banks loan portfolio structure, we conducted analysis for five sectors: industry, construction, agriculture, services and the overall economy. For each sector the average default probability at time t is modeled as a logistic function of many general and sector-specific macroeconomic variables. The use of logistic regression was motivated by its ability to account for fractional data between 0 and 1. We found that at least one variable from each group has a significant explanatory power regarding the evolution of the default rates in all five sectors analyzed. In some cases the sign of the variables was the opposite of what the economic theory would have suggested, but it has to be taken into account that Romania posted the picture of an overheated economy during the analyzed period. Another important conclusion was that many variables were significant through their lagged value, which indicates an even better supervision of the evolution of the specific variables. From all

  12. Student Loan Defaults. Oversight Hearing Before the Subcommittee on Postsecondary Education of the Committee on Education and Labor, House of . Representatives.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    Hearings are presented on the subject of defaults of student loans made pursuant to the Guaranteed Student Loan Program authorized by part B of Title IV of the Higher Education Act. Methods are suggested for cutting down or eliminating defaults including: (1) discharging federal employees who have defaulted on student loans, after a reasonable…

  13. Ag85A DNA疫苗加强免疫显著提高卡介苗初免小鼠的抗结核T细胞免疫应答%Ag85A DNA vaccination boosting enhances BCG primed-mice anti-tuberculosis T cell responses

    Institute of Scientific and Technical Information of China (English)

    康涵; 范小勇; 袁琴; 吴福明; 沈芳

    2013-01-01

    Objective To construct DNA vaccine expressing Mycobacterium tuberculosis(Mtb) immunodominant antigen Ag85A and analyze its anti-tuberculosis T cell responses in BCG primed-mice after DNA vaccination boosting.Methods The coding gene of Ag85A mature fragment was amplified by PCR with H37Rv genomic DNA as template,and then cloned into the eukaryotic expression vector pVAX1 to construct Ag85A DNA vaccine.After purification,Ag85A DNA vaccine was injected intramuscularly twice in BCG primed-mice with BCG vaccination and DNA vaccination alone as control.Eight weeks post-vaccination,spleen lymphocytes were separated and were then used to analyze Mtb antigen specific effector T cell response and polyfuntional IFN-γ/TNF-α/IL-2 secreting CD4+ T cell frequencies and intensities,and CD8+T cell responses by IFN-γ ELISPOT assay and intracellular staining,respectively.Results Compared to BCG vaccinated-and DNA vaccinated-mice,Ag85A DNA boosting not only enhanced significantly BCG primed-mice IFN-γ+TNF-α+IL-2+,IFN-γ+ IL-2+,TNF-α+IL-2+ and IL-2+ CD4+ T cell frequencies and IL-2 secretion,but also improved significantly IFN-γ-secreting and IL-2-secreting CD8+ T cell frequencies.Condusion Ag85A DNA vaccine was constructed successfully and was demonstrated to enhance significantly BCG primed-mice Mtb antigen specific CD4+ and CD8+ T cell responses when boosting,which is beneficial to improve BCG immunogenicity and its waning immune protection against Mtb.%目的 构建表达结核分枝杆菌(Mycobacterium tuberculosis,Mtb)免疫优势抗原Ag85A的DNA疫苗,分析其加强免疫后提高卡介苗(BCG)初免小鼠的抗结核T细胞免疫应答.方法 以Mtb毒株H37Rv基因组DNA为模板,PCR扩增Ag85A抗原编码的结构基因并克隆至真核表达载体pVAX1中构建其DNA疫苗;接着,将纯化后的该DNA疫苗加强免疫BCG初免小鼠2针,以BCG和DNA单独免疫小鼠为对照,免疫8周后无菌分离脾淋巴细胞,分别应用IFN-γ ELISPOT和多

  14. Changes in the default mode network in the prefrontal lobe, posterior cingulated cortex and hippocampus of heroin users

    Institute of Scientific and Technical Information of China (English)

    Wenfu Hu; Xiangming Fu; Ruobing Qian; Xiangpin Wei; Xuebing Ji; Chaoshi Niu

    2012-01-01

    The default mode network is associated with senior cognitive functions in humans. In this study, we performed independent component analysis of blood oxygenation signals from 14 heroin users and 13 matched normal controls in the resting state through functional MRI scans. Results showed that the default mode network was significantly activated in the prefrontal lobe, posterior cingulated cortex and hippocampus of heroin users, and an enhanced activation signal was observed in the right inferior parietal lobule (P < 0.05, corrected for false discovery rate). Experimental findings indicate that the default mode network is altered in heroin users.

  15. Surgery in the treatment of malignant pleural mesothelioma: recruitment into trials should be the default position

    OpenAIRE

    Datta, Avijit; Smith, Rhiannon; Fiorentino, Francesca; Treasure, Tom

    2013-01-01

    Background Europe is at the peak of an epidemic of malignant pleural mesothelioma and the burden of disease is likely to continue rising in the large areas of the world where asbestos remains unregulated. Patients with mesothelioma present with thoracic symptoms and radiological changes so respiratory physicians take a leading role in diagnosis and management. Belief that the modest survival times reported after radical surgery, whether alone or as part of multimodal therapy, are longer than ...

  16. Etiology of phantom limb syndrome: Insights from a 3D default space consciousness model.

    Science.gov (United States)

    Jerath, Ravinder; Crawford, Molly W; Jensen, Mike

    2015-08-01

    In this article, we examine phantom limb syndrome to gain insights into how the brain functions as the mind and how consciousness arises. We further explore our previously proposed consciousness model in which consciousness and body schema arise when information from throughout the body is processed by corticothalamic feedback loops and integrated by the thalamus. The parietal lobe spatially maps visual and non-visual information and the thalamus integrates and recreates this processed sensory information within a three-dimensional space termed the "3D default space." We propose that phantom limb syndrome and phantom limb pain arise when the afferent signaling from the amputated limb is lost but the neural circuits remain intact. In addition, integration of conflicting sensory information within the default 3D space and the loss of inhibitory afferent feedback to efferent motor activity from the amputated limb may underlie phantom limb pain. PMID:26003829

  17. Portfolio optimization in a defaults model under full/partial information

    CERN Document Server

    Lim, Thomas

    2010-01-01

    In this paper, we consider a financial market with assets exposed to some risks inducing jumps in the asset prices, and which can still be traded after default times. We use a default-intensity modeling approach, and address in this incomplete market context the problem of maximization of expected utility from terminal wealth for logarithmic, power and exponential utility functions. We study this problem as a stochastic control problem both under full and partial information. Our contribution consists in showing that the optimal strategy can be obtained by a direct approach for the logarithmic utility function, and the value function for the power utility function can be determined as the minimal solution of a backward stochastic differential equation. For the partial information case, we show how the problem can be divided into two problems: a filtering problem and an optimization problem. We also study the indifference pricing approach to evaluate the price of a contingent claim in an incomplete market and ...

  18. Musical Creativity "Revealed" in Brain Structure: Interplay between Motor, Default Mode, and Limbic Networks.

    Science.gov (United States)

    Bashwiner, David M; Wertz, Christopher J; Flores, Ranee A; Jung, Rex E

    2016-01-01

    Creative behaviors are among the most complex that humans engage in, involving not only highly intricate, domain-specific knowledge and skill, but also domain-general processing styles and the affective drive to create. This study presents structural imaging data indicating that musically creative people (as indicated by self-report) have greater cortical surface area or volume in a) regions associated with domain-specific higher-cognitive motor activity and sound processing (dorsal premotor cortex, supplementary and pre-supplementary motor areas, and planum temporale), b) domain-general creative-ideation regions associated with the default mode network (dorsomedial prefrontal cortex, middle temporal gyrus, and temporal pole), and c) emotion-related regions (orbitofrontal cortex, temporal pole, and amygdala). These findings suggest that domain-specific musical expertise, default-mode cognitive processing style, and intensity of emotional experience might all coordinate to motivate and facilitate the drive to create music. PMID:26888383

  19. Musical Creativity “Revealed” in Brain Structure: Interplay between Motor, Default Mode, and Limbic Networks

    Science.gov (United States)

    Bashwiner, David M.; Wertz, Christopher J.; Flores, Ranee A.; Jung, Rex E.

    2016-01-01

    Creative behaviors are among the most complex that humans engage in, involving not only highly intricate, domain-specific knowledge and skill, but also domain-general processing styles and the affective drive to create. This study presents structural imaging data indicating that musically creative people (as indicated by self-report) have greater cortical surface area or volume in a) regions associated with domain-specific higher-cognitive motor activity and sound processing (dorsal premotor cortex, supplementary and pre-supplementary motor areas, and planum temporale), b) domain-general creative-ideation regions associated with the default mode network (dorsomedial prefrontal cortex, middle temporal gyrus, and temporal pole), and c) emotion-related regions (orbitofrontal cortex, temporal pole, and amygdala). These findings suggest that domain-specific musical expertise, default-mode cognitive processing style, and intensity of emotional experience might all coordinate to motivate and facilitate the drive to create music. PMID:26888383

  20. Measuring the default risk of sovereign debt from the perspective of network

    Science.gov (United States)

    Chuang, Hongwei; Ho, Hwai-Chung

    2013-05-01

    Recently, there has been a growing interest in network research, especially in the fields of biology, computer science, and sociology. It is natural to address complex financial issues such as the European sovereign debt crisis from the perspective of network. In this article, we construct a network model according to the debt-credit relations instead of using the conventional methodology to measure the default risk. Based on the model, a risk index is examined using the quarterly report of consolidated foreign claims from the Bank for International Settlements (BIS) and debt/GDP ratios among these reporting countries. The empirical results show that this index can help the regulators and practitioners not only to determine the status of interconnectivity but also to point out the degree of the sovereign debt default risk. Our approach sheds new light on the investigation of quantifying the systemic risk.

  1. A mechanism for ultra-slow oscillations in the cortical default network.

    Science.gov (United States)

    Steyn-Ross, Moira L; Steyn-Ross, D A; Sleigh, J W; Wilson, M T

    2011-02-01

    When the brain is in its noncognitive "idling" state, functional MRI measurements reveal the activation of default cortical networks whose activity is suppressed during cognitive processing. This default or background mode is characterized by ultra-slow BOLD oscillations (∼0.05 Hz), signaling extremely slow cycling in cortical metabolic demand across distinct cortical regions. Here we describe a model of the cortex which predicts that slow cycling of cortical activity can arise naturally as a result of nonlinear interactions between temporal (Hopf) and spatial (Turing) instabilities. The Hopf instability is triggered by delays in the inhibitory postsynaptic response, while the Turing instability is precipitated by increases in the strength of the gap-junction coupling between interneurons. We comment on possible implications for slow dendritic computation and information processing. PMID:20821063

  2. DEFAULT RISK MANAGEMENT IN LOCAL AREA BANKS - CASE STUDY OF KBS BANK LTD

    Directory of Open Access Journals (Sweden)

    Mustari Hanmanth. N

    2014-04-01

    Full Text Available The default risk arises from a borrower's failure to pay interest or principal or both on loans and securities as promised. It is the potential that a bank borrower/counterparty fails to meet the obligations on agreed terms. There is always scope for the borrower to default from his/her comments for one or other reason resulting in crystalisation of credit risk to the bank. Credit risk is inherent to the business of lending funds to the operations linked closely to market risk variables. The objective of credit risk management is to minimize the risk and maximize bank risk adjusted rate of return by assuming and maintaining credit exposure within the acceptable parameters

  3. Stochastic control under progressive enlargement of filtrations and applications to multiple defaults risk management

    CERN Document Server

    Pham, Huyen

    2010-01-01

    We formulate and investigate a general stochastic control problem under a progressive enlargement of filtration. The global information is enlarged from a reference filtration and the knowledge of multiple random times together with associated marks when they occur. By working under a density hypothesis on the conditional joint distribution of the random times and marks, we prove a decomposition of the original stochastic control problem under the global filtration into classical stochastic control problems under the reference filtration, which are determined in a finite backward induction. Our method revisits and extends in particular stochastic control of diffusion processes with finite number of jumps. This study is motivated by optimization problems arising in default risk management, and we provide applications of our decomposition result for the indifference pricing of defaultable claims, and the optimal investment under bilateral counterparty risk. The solutions are expressed in terms of BSDEs involvin...

  4. Inferring Acceptance and Rejection in Dialogue by Default Rules of Inference

    CERN Document Server

    Walker, M A

    1996-01-01

    This paper discusses the processes by which conversants in a dialogue can infer whether their assertions and proposals have been accepted or rejected by their conversational partners. It expands on previous work by showing that logical consistency is a necessary indicator of acceptance, but that it is not sufficient, and that logical inconsistency is sufficient as an indicator of rejection, but it is not necessary. I show how conversants can use information structure and prosody as well as logical reasoning in distinguishing between acceptances and logically consistent rejections, and relate this work to previous work on implicature and default reasoning by introducing three new classes of rejection: {\\sc implicature rejections}, {\\sc epistemic rejections} and {\\sc deliberation rejections}. I show how these rejections are inferred as a result of default inferences, which, by other analyses, would have been blocked by the context. In order to account for these facts, I propose a model of the common ground that...

  5. Exploring the electrophysiological correlates of the default-mode network with intracerebral EEG

    Directory of Open Access Journals (Sweden)

    Karim Jerbi

    2010-06-01

    Full Text Available While functional imaging studies allow for a precise spatial characterization of resting state networks, their neural correlates and thereby their fine-scale temporal dynamics remain elusive. A full understanding of the mechanisms at play requires input from electrophysiological studies. Here, we discuss human and non-human primate electrophysiological data that explore the neural correlates of the default-mode network. Beyond the promising findings obtained with non-invasive approaches, emerging evidence suggests that invasive recordings in humans will be crucial in order to elucidate the neural correlates of the brain’s default-mode function. In particular, we contend that stereotactic-electroencephalography (SEEG, which consists of implanting multiple depth electrodes for pre-surgical evaluation in drug-resistant epilepsy, is particularly suited for this endeavor. We support this view by providing rare data from depth recordings in human posterior cingulate cortex and medial prefrontal cortex that show transient neural deactivation during task-engagement.

  6. Default Spread dan Term Spread Sebagai Variabel Proxy Siklus Bisnis Pada Model Fama-French

    Directory of Open Access Journals (Sweden)

    Edwin Hendra

    2015-08-01

    yield spread, default spread (RBBB RAAA and RAAA RF, and the term spread (RSUN10-RSUN1, as proxy variables of the business cycle, in IDX stock data during 2005-2010. Four types of asset pricing models tested are Sharpe-Lintner CAPM, Fama-French models, Hwang et al.model, and hybrid model. The results showed that the size effect and value effect has an impact on excess stock returns. Slopes of market beta, SMB, and HML are more sensitive to stock big size and high B / M. Default spreads and term spreads in Hwang et al. model can explain the value effect, and weakly explain the size effect, meanwhile the power of explanation disappeared on Hybrid models. Based on the assessment adjusted R2 and the frequency of rejection of non-zero alpha, is found that the hybrid model is the most suitable model.

  7. Sovereign Default Risk and Private Sector Access to Capital in Emerging Markets

    OpenAIRE

    Das, Udaibir S.; Michael G Papaioannou; Christoph Trebesch

    2010-01-01

    Top down spillovers of sovereign default risk can have serious consequences for the private sector in emerging markets. This paper analyzes the effects of these spillovers using firm-level data from 31 emerging market economies. We assess how sovereign risk affects corporate access to international capital markets, in the form of external credit (loans and bond issuances) and equity issuances. The study first analyzes the impact of sovereign debt crises during the 1980s and 1990s. It goes on ...

  8. Existing Default Values and Recommendations for Exposure Assessment - A Nordic Exposure Group Project 2011

    DEFF Research Database (Denmark)

    Höglund, Lena; Räisänen, Jouni; Hämäläinen, Anne-Maija;

    ) and children in relation to REACH. Another important purpose of the report is to contribute towards a further harmonisation of exposure factors by giving recommendations of most valid and representative defaults. These recommendations can be used besides REACH also in biocide's and plant protection...... rate, soil and dust ingestion, drinking water, food intake, non-dietary ingestion factors, lifetime expectancy, activity factors and consumer products...

  9. Dopamine Transporters in Striatum Correlate with Deactivation in the Default Mode Network during Visuospatial Attention

    OpenAIRE

    Dardo Tomasi; Volkow, Nora D.; Ruiliang Wang; Frank Telang; Gene-Jack Wang; Linda Chang; Thomas Ernst; Fowler, Joanna S.

    2009-01-01

    BACKGROUND: Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation i...

  10. Nudging Sustainable Food Choices. The Role of Defaults, Frames, Habits and Nature Relatedness

    OpenAIRE

    Hohle, Sigrid Møyner

    2014-01-01

    Reduced consumption of meat could help mitigate climate change and health problems. Nudging is one approach to individual behavior change. By nudging, the choice context is designed to facilitate certain decisions. In the present field experiment, three different nudges were tested, aiming at increasing vegetarian food selection among 353 customers in a café. The menu was changed so that the vegetarian food options were either presented as the dish of the day (DEFAULT) or given a more attra...

  11. The Comovement of credit default swap, bond and stock markets : an empirical analysis

    OpenAIRE

    Norden, Lars; WEBER, Martin

    2004-01-01

    This paper analyzes the empirical relationship between credit default swap, bond and stock markets during the period 2000-2002. Focusing on the intertemporal comovement, we examine weekly and daily lead-lag relationships in a vector autoregressive model and the adjustment between markets caused by cointegration. First, we find that stock returns lead CDS and bond spread changes. Second, CDS spread changes Granger cause bond spread changes for a higher number of firms than vice versa. Third, t...

  12. An empirical comparison of credit spreads between the bond market and the credit default swap market

    OpenAIRE

    Haibin Zhu

    2004-01-01

    This paper compares the pricing of credit risk in the bond market and the fast-growing credit default swap (CDS) market. The empirical findings confirm the theoretical prediction that bond spreads and CDS spreads move together in the long run. Nevertheless, in the short run this relationship does not always hold. The deviation is largely due to different responses of the two markets to changes in credit conditions. By looking into the dynamic linkages between the two spreads, I find that the ...

  13. Differential synchronization in default and task-specific networks of the human brain

    Directory of Open Access Journals (Sweden)

    Aaron Kirschner

    2012-05-01

    Full Text Available On a regional scale the brain is organized into dynamic functional networks. The activity within one of these, the default network, can be dissociated from that in other task-specific networks. All brain networks are connected structurally, but evidently are only transiently connected functionally. One hypothesis as to how such transient functional coupling occurs is that network formation and dissolution is mediated, or at least accompanied, by increases and decreases in oscillatory synchronization between constituent brain regions. If so, then we should be able to find transient differences in intra-network synchronization between the default network and a task-specific network. In order to investigate this hypothesis we conducted two experiments in which subjects engaged in a Sustained Attention to Response Task (SART while having brain activity recorded via high-density electroencephalography (EEG. We found that during periods when attention was focused internally (mind-wandering there was significantly more neural phase synchronization between brain regions associated with the default network, whereas during periods when subjects were focused on performing the visual task there was significantly more neural phase synchrony within a task-specific brain network that shared some of the same brain regions. These differences in network synchrony occurred in each of theta, alpha, and gamma frequency bands. A similar pattern of differential oscillatory power changes, indicating modulation of local synchronization by attention state, was also found. These results provide further evidence that the human brain is intrinsically organized into default and task-specific brain networks, and confirm that oscillatory synchronization is a potential mechanism for functional coupling within these networks.

  14. Competition and Diversification Effects in Supply Chains with Supplier Default Risk

    OpenAIRE

    Volodymyr Babich; Burnetas, Apostolos N.; Ritchken, Peter H

    2007-01-01

    We study the effects of disruption risk in a supply chain where one retailer deals with competing risky suppliers who may default during their production lead times. The suppliers, who compete for business with the retailer by setting wholesale prices, are leaders in a Stackelberg game with the retailer. The retailer, facing uncertain future demand, chooses order quantities while weighing the benefits of procuring from the cheapest supplier against the advantages of order diversification. For...

  15. Age effect on the default mode network, inner thoughts, and cognitive abilities.

    OpenAIRE

    Mevel, Katell; Landeau, Brigitte; Fouquet, Marine; La Joie, Renaud; Villain, Nicolas; Mézenge, Florence; Perrotin, Audrey; Eustache, Francis; Desgranges, Beatrice; Chételat, Gaël

    2013-01-01

    International audience Age-related effects on the default mode network (DMN) connectivity as measured at rest using functional magnetic resonance imaging (fMRI) are now well described. Little is known however about the relationships between these changes and age-related effects on cognition or on the unconstrained thoughts which occur during the resting-state scan, called inner experience. Brain resting-state activity, inner experience, and cognitive ability measurements were obtained in 7...

  16. A default mode of brain function in altered states of consciousness.

    OpenAIRE

    Guldenmund, Justus Pieter; Vanhaudenhuyse, Audrey; Boly, Mélanie; Laureys, Steven; Soddu, Andrea

    2012-01-01

    Using modern brain imaging techniques, new discoveries are being made concerning the spontaneous activity of the brain when it is devoid of attention-demanding tasks. Spatially separated patches of neuronal assemblies have been found to show synchronized oscillatory activity behavior and are said to be functionally connected. One of the most robust of these is the default mode network, which is associated with intrinsic processes like mind wandering and self-projection. Furthermore, activity ...

  17. Default options in advance directives: study protocol for a randomised clinical trial

    OpenAIRE

    Gabler, Nicole B.; Cooney, Elizabeth; Small, Dylan S.; Troxel, Andrea B.; Arnold, Robert M.; White, Douglas B.; Angus, Derek C.; Loewenstein, George; Volpp, Kevin G; Bryce, Cindy L.; Halpern, Scott D.

    2016-01-01

    Introduction Although most seriously ill Americans wish to avoid burdensome and aggressive care at the end of life, such care is often provided unless patients or family members specifically request otherwise. Advance directives (ADs) were created to provide opportunities to set limits on aggressive care near life's end. This study tests the hypothesis that redesigning ADs such that comfort-oriented care is provided as the default, rather than requiring patients to actively choose it, will pr...

  18. Potential impact of licensee default on cleanup of TMI-2. Technical report

    International Nuclear Information System (INIS)

    Financial repercussions of the accident at Three Mile Island Unit 2 on the ability of the Licensee, Metropolitan Edison Co., to complete cleanup of the facility are examined. Potential impacts of licensee default on cleanup and alternatives to minimize the potential of bankruptcy are discussed. Specific recommendations are made regarding steps the Nuclear Regulatory Commission might take in keeping with its regulatory functions and its mission to protect the public health and safety

  19. State dissolution, sovereign debt and default:Lessons from the UK and Ireland, 1920-1938

    OpenAIRE

    Foley-Fisher, Nathan; McLaughlin, Eoin

    2014-01-01

    We study Ireland´s inheritance of debt following its secession from the United Kingdom at the beginning of the twentieth century. Exploiting structural differences in bonds guaranteed by the UK and Irish governments, we can identify perceived uncertainty about fiscal responsibility in the aftermath of the sovereign breakup. We document that Ireland´s default on intergovernmental payments was an important event. Although payments from the Irish government ceased, the UK government instructed i...

  20. Default options in advance directives: study protocol for a randomised clinical trial

    Science.gov (United States)

    Gabler, Nicole B; Cooney, Elizabeth; Small, Dylan S; Troxel, Andrea B; Arnold, Robert M; White, Douglas B; Angus, Derek C; Loewenstein, George; Volpp, Kevin G; Bryce, Cindy L; Halpern, Scott D

    2016-01-01

    Introduction Although most seriously ill Americans wish to avoid burdensome and aggressive care at the end of life, such care is often provided unless patients or family members specifically request otherwise. Advance directives (ADs) were created to provide opportunities to set limits on aggressive care near life's end. This study tests the hypothesis that redesigning ADs such that comfort-oriented care is provided as the default, rather than requiring patients to actively choose it, will promote better patient-centred outcomes. Methods and analysis This multicentre trial randomises seriously ill adults to receive 1 of 3 different ADs: (1) a traditional AD that requires patients to actively choose their goals of care or preferences for specific interventions (eg, feeding tube insertion) or otherwise have their care guided by their surrogates and the prevailing societal default toward aggressive care; (2) an AD that defaults to life-extending care and receipt of life-sustaining interventions, enabling patients to opt out from such care; or (3) an AD that defaults to comfort care, enabling patients to opt into life-extending care. We seek to enrol 270 patients who return complete, legally valid ADs so as to generate sufficient power to detect differences in the primary outcome of hospital-free days (days alive and not in an acute care facility). Secondary outcomes include hospital and intensive care unit admissions, costs of care, hospice usage, decision conflict and satisfaction, quality of life, concordance of preferences with care received and bereavement outcomes for surrogates of patients who die. Ethics and dissemination This study has been approved by the Institutional Review Boards at all trial centres, and is guided by a data safety and monitoring board and an ethics advisory board. Study results will be disseminated using methods that describe the results in ways that key stakeholders can best understand and implement. Trial registration number NCT02017548

  1. On Strong and Default Negation in Logic Program Updates (Extended Version)

    OpenAIRE

    Slota, Martin; Baláz, Martin; Leite, João

    2014-01-01

    Existing semantics for answer-set program updates fall into two categories: either they consider only strong negation in heads of rules, or they primarily rely on default negation in heads of rules and optionally provide support for strong negation by means of a syntactic transformation. In this paper we pinpoint the limitations of both these approaches and argue that both types of negation should be first-class citizens in the context of updates. We identify principles that plausibly constra...

  2. The Self-Pleasantness Judgment Modulates the Encoding Performance and the Default Mode Network Activity

    OpenAIRE

    Perrone-Bertolotti, Marcela; Cerles, Melanie; Ramdeen, Kylee T.; Boudiaf, Naila; Pichat, Cedric; Hot, Pascal; Baciu, Monica

    2016-01-01

    In this functional magnetic resonance imaging (fMRI) study, we evaluated the effect of self-relevance on cerebral activity and behavioral performance during an incidental encoding task. Recent findings suggest that pleasantness judgments reliably induce self-oriented (internal) thoughts and increase default mode network (DMN) activity. We hypothesized that this increase in DMN activity would relate to increased memory recognition for pleasantly-judged stimuli (which depend on internally-orien...

  3. Top-down regulation of default mode activity in spatial visual attention

    OpenAIRE

    Wen, Xiaotong; Liu, Yijun; Yao, Li; Ding, Mingzhou

    2013-01-01

    Dorsal anterior cingulate and bilateral anterior insula form a task control network (TCN) whose primary function includes initiating and maintaining task-level cognitive set and exerting top-down regulation of sensorimotor processing. The default mode network (DMN), comprising an anatomically distinct set of cortical areas, mediates introspection and self-referential processes. Resting-state data show that TCN and DMN interact. The functional ramifications of their interaction remain elusive....

  4. Hypnotic modulation of resting state fMRI default mode and extrinsic network connectivity

    OpenAIRE

    Demertzi, Athina; Soddu, Andrea; Faymonville, Marie-Elisabeth; Bahri, Mohamed Ali; Gosseries, Olivia; Vanhaudenhuyse, Audrey; Phillips, Christophe; Maquet, Pierre; Luxen, André; Laureys, Steven

    2011-01-01

    Resting state fMRI (functional magnetic resonance imaging) acquisitions are characterized by low-frequency spontaneous activity in a default mode network (encompassing medial brain areas and linked to self-related processes) and an anticorrelated “extrinsic” system (encompassing lateral frontoparietal areas and modulated via external sensory stimulation). In order to better determine the functional contribution of these networks to conscious awareness, we here sought to transiently modulat...

  5. Differential Deactivation during Mentalizing and Classification of Autism Based on Default Mode Network Connectivity

    OpenAIRE

    Murdaugh, Donna L.; Shinkareva, Svetlana V.; Deshpande, Hrishikesh R.; Jing Wang; Pennick, Mark R; Kana, Rajesh K.

    2012-01-01

    The default mode network (DMN) is a collection of brain areas found to be consistently deactivated during task performance. Previous neuroimaging studies of resting state have revealed reduced task-related deactivation of this network in autism. We investigated the DMN in 13 high-functioning adults with autism spectrum disorders (ASD) and 14 typically developing control participants during three fMRI studies (two language tasks and a Theory-of-Mind (ToM) task). Each study had separate blocks ...

  6. Alterations of Resting State Functional Connectivity in the Default Network in Adolescents with Autism Spectrum Disorders

    OpenAIRE

    Weng, Shih-Jen; Wiggins, Jillian Lee; Peltier, Scott J.; Carrasco, Melisa; Risi, Susan; Lord, Catherine; Monk, Christopher S.

    2009-01-01

    Autism spectrum disorders (ASD) are associated with disturbances of neural connectivity. Functional connectivity between neural structures is typically examined within the context of a cognitive task, but also exists in the absence of a task (i.e., “rest”). Connectivity during rest is particularly active in a set of structures called the default network, which includes the posterior cingulate cortex (PCC), retrosplenial cortex, lateral parietal cortex/angular gyrus, medial prefrontal cortex, ...

  7. Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

    OpenAIRE

    Čeko, Marta; Gracely, John L.; Fitzcharles, Mary-Ann; Seminowicz, David A.; Schweinhardt, Petra; Bushnell, M. Catherine

    2015-01-01

    In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or “negative” [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether ...

  8. Analysis of the CSLP Student Loan Defaulter Survey and Client Satisfaction Surveys

    OpenAIRE

    Lochner, Lance; Stinebrickner, Todd; Suleymanoglu, Utku

    2013-01-01

    This analysis confirms our findings from the Defaulter Survey regarding quantitatively important relationships between repayment problems and borrower income. We also identify an important role for student debt, educational attainment, and beliefs about repayment. The analysis further reveals the importance of intergenerational relationships for repayment. Children whose parents are able and willing to financially help them out in times of economic stress are much less likely to experience re...

  9. Self-Processing and the Default Mode Network: Interactions with the Mirror Neuron System

    OpenAIRE

    Istvan Molnar-Szakacs; Lucina Q. Uddin

    2013-01-01

    Recent evidence for the fractionation of the default mode network (DMN) into functionally distinguishable subdivisions with unique patterns of connectivity calls for a reconceptualization of the relationship between this network and self-referential processing. Advances in resting-state functional connectivity analyses are beginning to reveal increasingly complex patterns of organization within the key nodes of the DMN - medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC) – a...

  10. Abnormal Brain Default-Mode Network Functional Connectivity in Drug Addicts

    OpenAIRE

    Ma, Ning; Liu, Ying; Fu, Xian-ming; Li, Nan; Wang, Chang-Xin; Zhang, Hao; Qian, Ruo-Bing; Xu, Hu-Sheng; Hu, Xiaoping; Zhang, Da-Ren

    2011-01-01

    Background The default mode network (DMN) is a set of brain regions that exhibit synchronized low frequency oscillations at resting-state, and is believed to be relevant to attention and self-monitoring. As the anterior cingulate cortex and hippocampus are impaired in drug addiction and meanwhile are parts of the DMN, the present study examined addiction-related alteration of functional connectivity of the DMN. Methodology Resting-state functional magnetic resonance imaging data of chronic he...

  11. The recent elections may have only postponed Greece’s default and Eurozone exit

    OpenAIRE

    Halikiopoulou, Daphne; Vasilopoulou, Sofia

    2012-01-01

    Last Sunday’s elections in Greece saw the pro-bailout New Democracy party gain the largest share of the vote, reassuring many commentators who had been fearing a default by Greece or even its ejection from the Eurozone. Daphne Halikiopoulou and Sofia Vasilopoulou argue, however, that anti-bailout parties in Greece received widespread support – there is still a deep division in Greek politics. This cannot be solved until the underlying problems of corruption, nepotism and client...

  12. Assessing Credit Default using Logistic Regression and Multiple Discriminant Analysis: Empirical Evidence from Bosnia and Herzegovina

    OpenAIRE

    Deni Memić

    2015-01-01

    This article has an aim to assess credit default prediction on the banking market in Bosnia and Herzegovina nationwide as well as on its constitutional entities (Federation of Bosnia and Herzegovina and Republika Srpska). Ability to classify companies info different predefined groups or finding an appropriate tool which would replace human assessment in classifying companies into good and bad buckets has been one of the main interests on risk management researchers for a long time. We investi...

  13. A Default Model of The Non-listed Companies Under Asymmetric Information

    Institute of Scientific and Technical Information of China (English)

    Wang Fake

    2013-01-01

    For the financing difficulties of the non-listed companies, A continuous credit risk model is created which is based on the asymmetric information theory.In the model,the value of the non-listed companies is estimated by the free cash flow,and the loan discussed contains the collateral asset.Based on the model,The default probability,the LGD and the largest company debts are discussed.

  14. Brain functional connectivity, dopamine and the default mode network in ADHD

    OpenAIRE

    Richard Bernard Silberstein

    2015-01-01

    Recent evidence suggests that Attention Deficit Hyperactivity Disorder (ADHD) is associated with reduced inhibition of the default mode network (DMN) while performing a cognitive task. In this study, we use steady state visual evoked potential event related partial coherence as a measure of brain functional connectivity to examine functional connectivity differences between a control group of 25 boys and an age/IQ matched group of 42 boys newly diagnosed with ADHD. Functional connectivity w...

  15. The relative informational efficiency of stocks, options and credit default swaps during the financial crisis

    OpenAIRE

    Maria Chiara Amadori; Lamia Bekkour; Thorsten Lehnert

    2014-01-01

    Purpose – This paper aims to investigate informational efficiency of stock, options and credit default swap (CDS) markets. Previous research suggests that informed traders prefer equity option and CDS markets over stock markets to exploit their informational advantage. As a result, equity and credit derivative markets contribute more to price discovery compared to stock markets. Design/methodology/approach -In this study, the authors investigate the dynamics behind informed investors’ trading...

  16. On the relationship between the “default mode network” and the “social brain”

    OpenAIRE

    Mars, Rogier B.; Noonan, MaryAnn P.

    2012-01-01

    The default mode network (DMN) of the brain consists of areas that are typically more active during rest than during active task performance. Recently however, this network has been shown to be activated by certain types of tasks. Social cognition, particularly higher-order tasks such as attributing mental states to others, has been suggested to activate a network of areas at least partly overlapping with the DMN. Here, we explore this claim, drawing on evidence from meta-analyses of function...

  17. A default prior distribution for contingency tables with dependent factor levels

    OpenAIRE

    Overstall, Antony M.; King, Ruth

    2014-01-01

    A default prior distribution is proposed for the Bayesian analysis of contingency tables. The prior is specified to allow for dependence between levels of the factors. Different dependence structures are considered, including conditional autoregressive and distance correlation structures. To demonstrate the prior distribution, a dataset is considered which involves estimating the number of injecting drug users in the eleven National Health Service board regions of Scotland using an incomplete...

  18. The default mode network and social understanding of others: what do brain connectivity studies tell us

    OpenAIRE

    Li, Wanqing; Mai, Xiaoqin; Liu, Chao

    2014-01-01

    The Default Mode Network (DMN) has been found to be involved in various domains of cognitive and social processing. The present article will review brain connectivity results related to the DMN in the fields of social understanding of others: emotion perception, empathy, theory of mind, and morality. Most of the reviewed studies focused on healthy subjects with no neurological and psychiatric disease, but some studies on patients with autism and psychopathy will also be discussed. Common resu...

  19. The Default Mode Network and Social Understanding of Others: What do Brain Connectivity Studies Tell Us

    OpenAIRE

    Wanqing eLi; Xiaoqin eMai; Chao eLiu

    2014-01-01

    The Default Mode Network (DMN) has been found to be involved in various domains of cognitive and social processing. The present article will review brain connectivity results related to the DMN in the fields of social understanding of others: emotion perception, empathy, theory of mind, and morality. Most of the reviewed studies focused on healthy subjects with no neurological and psychiatric disease, but some studies on patients with autism and psychopathy will also be discussed. Common res...

  20. A Mathematical Method for Deriving the Relative Effect of Serviceability on Default Risk

    OpenAIRE

    Graham Andersen; David Chisholm

    2011-01-01

    The writers propose a mathematical Method for deriving risk weights which describe how a borrower's income, relative to their debt service obligations (serviceability) affects the probability of default of the loan. The Method considers the borrower's income not simply as a known quantity at the time the loan is made, but as an uncertain quantity following a statistical distribution at some later point in the life of the loan. This allows a probability to be associated with an income level le...

  1. Comparison of credit scoring models on probability of default estimation for US banks

    OpenAIRE

    Gurný, Petr; GURNÝ, MARTIN

    2013-01-01

    This paper is devoted to the estimation of the probability of default (PD) as a crucial parameter in risk management, requests for loans, rating estimation, pricing of credit derivatives and many others key fi nancial fi elds. Particularly, in this paper we will estimate the PD of US banks by means of the statistical models, generally known as credit scoring models. First, in theoretical part, we will briefl y introduce the two main categories of credit scoring models, which will ...

  2. Game Analysis of Microfinance Default Risk%小额信贷违约风险的博弈分析

    Institute of Scientific and Technical Information of China (English)

    段霞

    2014-01-01

    Default risk between microfinance institutions and farmers severely restricted the effective operation and sustainable development of microfinance. In this paper, by establishing the static game model and dynamic game model to analyze microfinance risk of default, getting measures of reducing the risk of small credit default, and giving suggestions for preventing microfinance risk of default.%小额信贷机构与农户之间的违约风险严重制约了小额信贷的有效运作与可持续发展。通过建立静态博弈模型及动态博弈模型对小额信贷违约风险进行分析,得到降低小额信贷违约风险的措施,并为防范小额信贷违约风险提出建议。

  3. From default probabilities to credit spreads: credit risk models explain market prices (Keynote Address)

    Science.gov (United States)

    Denzler, Stefan M.; Dacorogna, Michel M.; Muller, Ulrich A.; McNeil, Alexander J.

    2005-05-01

    Credit risk models like Moody's KMV are now well established in the market and give bond managers reliable default probabilities for individual firms. Until now it has been hard to relate those probabilities to the actual credit spreads observed on the market for corporate bonds. Inspired by the existence of scaling laws in financial markets by Dacorogna et al. 2001 and DiMatteo et al. 2005 deviating from the Gaussian behavior, we develop a model that quantitatively links those default probabilities to credit spreads (market prices). The main input quantities to this study are merely industry yield data of different times to maturity and expected default frequencies (EDFs) of Moody's KMV. The empirical results of this paper clearly indicate that the model can be used to calculate approximate credit spreads (market prices) from EDFs, independent of the time to maturity and the industry sector under consideration. Moreover, the model is effective in an out-of-sample setting, it produces consistent results on the European bond market where data are scarce and can be adequately used to approximate credit spreads on the corporate level.

  4. Regularities and discrepancies of credit default swaps: a data science approach through Benford's law

    Science.gov (United States)

    Ausloos, Marcel; Castellano, Rosella; Cerqueti, Roy

    2016-09-01

    In this paper, we search whether the Benford's law is applicable to monitor daily changes in sovereign Credit Default Swaps (CDS) quotes, which are acknowledged to be complex systems of economic content. This test is of paramount importance since the CDS of a country proxy its health and probability to default, being associated to an insurance against the event of its default. We fit the Benford's law to the daily changes in sovereign CDS spreads for 13 European countries, - both inside and outside the European Union and European Monetary Union. Two different tenors for the sovereign CDS contracts are considered: 5 yrs and 10 yrs, - the former being the reference and most liquid one. The time period under investigation is 2008-2015 which includes the period of distress caused by the European sovereign debt crisis. Moreover, (i) an analysis over relevant sub-periods is carried out, (ii) several insights are provided also by implementing the tracking of the Benford's law over moving windows. The main test for checking the conformance to Benford's law is - as usual - the $\\chi^{2}$ test, whose values are presented and discussed for all cases. The analysis is further completed by elaborations based on Chebyshev's distance and Kullback and Leibler's divergence. The results highlight differences by countries and tenors. In particular, these results suggest that liquidity seems to be associated to higher levels of distortion. Greece - representing a peculiar case - shows a very different path with respect to the other European countries.

  5. Analysis on Risk Prevention Mechanism for Farmers’ Default in Small Amount Credit

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Through analysis, it is believed that major reasons for default risks in operation of small amount credit include low management level and vacancy of normative system, vacancy of risk sharing mechanism, rating distortion due to imperfect credit investigation system, and uncertainty of borrower’s credit. On the basis of these, static and dynamic models are established to analyze the prevention mechanism for default risk in small amount credit. It is concluded that we must establish a restriction mechanism during operation of small amount credit as long as three values increase, namely, N (potential loss of bad credit record due to farmers’ default), Q (probability of successful recovery by small amount credit institution), and S (cost of small amount credit institution punishing farmers after successful recovery). Finally, following countermeasures and suggestions are put forward: perfect laws and regulations and credit reward and punishment mechanism for risk management of small amount credit; bring into play proper function of loan officer in small amount credit practice; widely promote rural "Group Credit Union" system.

  6. Hypnotic modulation of resting state fMRI default mode and extrinsic network connectivity.

    Science.gov (United States)

    Demertzi, A; Soddu, A; Faymonville, M-E; Bahri, M A; Gosseries, O; Vanhaudenhuyse, A; Phillips, C; Maquet, P; Noirhomme, Q; Luxen, A; Laureys, S

    2011-01-01

    Resting state fMRI (functional magnetic resonance imaging) acquisitions are characterized by low-frequency spontaneous activity in a default mode network (encompassing medial brain areas and linked to self-related processes) and an anticorrelated "extrinsic" system (encompassing lateral frontoparietal areas and modulated via external sensory stimulation). In order to better determine the functional contribution of these networks to conscious awareness, we here sought to transiently modulate their relationship by means of hypnosis. We used independent component analysis (ICA) on resting state fMRI acquisitions during normal wakefulness, under hypnotic state, and during a control condition of autobiographical mental imagery. As compared to mental imagery, hypnosis-induced modulation of resting state fMRI networks resulted in a reduced "extrinsic" lateral frontoparietal cortical connectivity, possibly reflecting a decreased sensory awareness. The default mode network showed an increased connectivity in bilateral angular and middle frontal gyri, whereas its posterior midline and parahippocampal structures decreased their connectivity during hypnosis, supposedly related to an altered "self" awareness and posthypnotic amnesia. In our view, fMRI resting state studies of physiological (e.g., sleep or hypnosis), pharmacological (e.g., sedation or anesthesia), and pathological modulation (e.g., coma or related states) of "intrinsic" default mode and anticorrelated "extrinsic" sensory networks, and their interaction with other cerebral networks, will further improve our understanding of the neural correlates of subjective awareness. PMID:21854971

  7. Creativity and the default network: A functional connectivity analysis of the creative brain at rest☆

    Science.gov (United States)

    Beaty, Roger E.; Benedek, Mathias; Wilkins, Robin W.; Jauk, Emanuel; Fink, Andreas; Silvia, Paul J.; Hodges, Donald A.; Koschutnig, Karl; Neubauer, Aljoscha C.

    2014-01-01

    The present research used resting-state functional magnetic resonance imaging (fMRI) to examine whether the ability to generate creative ideas corresponds to differences in the intrinsic organization of functional networks in the brain. We examined the functional connectivity between regions commonly implicated in neuroimaging studies of divergent thinking, including the inferior prefrontal cortex and the core hubs of the default network. Participants were prescreened on a battery of divergent thinking tests and assigned to high- and low-creative groups based on task performance. Seed-based functional connectivity analysis revealed greater connectivity between the left inferior frontal gyrus (IFG) and the entire default mode network in the high-creative group. The right IFG also showed greater functional connectivity with bilateral inferior parietal cortex and the left dorsolateral prefrontal cortex in the high-creative group. The results suggest that the ability to generate creative ideas is characterized by increased functional connectivity between the inferior prefrontal cortex and the default network, pointing to a greater cooperation between brain regions associated with cognitive control and low-level imaginative processes. PMID:25245940

  8. Dissociation of regional activity in default mode network in medication-naive, first-episode somatization disorder.

    Directory of Open Access Journals (Sweden)

    Qinji Su

    Full Text Available BACKGROUND: Patients with somatization disorder (SD have altered neural activity in the brain regions of the default mode network (DMN. However, the regional alteration of the DMN in SD remains unknown. The present study was designed to investigate the regional alterations of the DMN in patients with SD at rest. METHODS: Twenty-five first-episode, medication-naive patients with SD and 28 age-, sex-, education- matched healthy controls underwent a resting-state functional magnetic resonance imaging (fMRI scan. The fractional amplitude of low-frequency fluctuations (fALFF was applied to analyze the data. RESULTS: Patients with SD showed a dissociation pattern of resting-state fALFF in the DMN, with increased fALFF in the bilateral superior medial prefrontal cortex (MPFC, BA8, 9 and decreased fALFF in the left precuneus (PCu, BA7. Furthermore, significantly positive correlation was observed between the z values of the voxels within the bilateral superior MPFC and somatization subscale scores of the Symptom Check List (SCL-90 in patients with SD. CONCLUSIONS: Our findings indicate that there is a dissociation pattern of the anterior and posterior DMN in first-episode, treatment-naive patients with SD. The results provide new insight for the importance of the DMN in the pathophysiology of SD.

  9. Decreased mental time travel to the past correlates with default-mode network disintegration under lysergic acid diethylamide.

    Science.gov (United States)

    Speth, Jana; Speth, Clemens; Kaelen, Mendel; Schloerscheidt, Astrid M; Feilding, Amanda; Nutt, David J; Carhart-Harris, Robin L

    2016-04-01

    This paper reports on the effects of LSD on mental time travel during spontaneous mentation. Twenty healthy volunteers participated in a placebo-controlled crossover study, incorporating intravenous administration of LSD (75 μg) and placebo (saline) prior to functional magnetic resonance imaging (fMRI). Six independent, blind judges analysed mentation reports acquired during structured interviews performed shortly after the functional magnetic resonance imaging (fMRI) scans (approximately 2.5 h post-administration). Within each report, specific linguistic references to mental spaces for the past, present and future were identified. Results revealed significantly fewer mental spaces for the past under LSD and this effect correlated with the general intensity of the drug's subjective effects. No differences in the number of mental spaces for the present or future were observed. Consistent with the previously proposed role of the default-mode network (DMN) in autobiographical memory recollection and ruminative thought, decreased resting-state functional connectivity (RSFC) within the DMN correlated with decreased mental time travel to the past. These results are discussed in relation to potential therapeutic applications of LSD and related psychedelics, e.g. in the treatment of depression, for which excessive reflection on one's past, likely mediated by DMN functioning, is symptomatic. PMID:26979587

  10. Timing of antiretroviral therapy and TB treatment outcomes in patients with TB-HIV in Myanmar

    Science.gov (United States)

    Shewade, H. D.; Kyaw, N. T. T.; Oo, M. M.; Aung, T. K.; Aung, S. T.; Oo, H. N.; Win, T.; Harries, A. D.

    2016-01-01

    Setting: Integrated HIV Care programme, Mandalay, Myanmar. Objectives: To determine time to starting antiretroviral treatment (ART) in relation to anti-tuberculosis treatment (ATT) and its association with TB treatment outcomes in patients co-infected with tuberculosis (TB) and the human immunodeficiency virus (HIV) enrolled from 2011 to 2014. Design: Retrospective cohort study. Results: Of 1708 TB-HIV patients, 1565 (92%) started ATT first and 143 (8%) started ART first. Treatment outcomes were missing for 226 patients and were thus not included. In those starting ATT first, the median time to starting ART was 8.6 weeks. ART was initiated after 8 weeks in 830 (53%) patients. Unsuccessful outcome was found in 7%, with anaemia being an independent predictor. In patients starting ART first, the median time to starting ATT was 21.6 weeks. ATT was initiated within 3 months in 56 (39%) patients. Unsuccessful outcome was found in 12%, and in 20% of those starting ATT within 3 months. Patients with CD4 count HIV-infected persons and close monitoring of anaemia and immunosuppression are recommended to further improve TB treatment outcomes among patients with TB-HIV.

  11. Induced sputum MMP-1, -3 & -8 concentrations during treatment of tuberculosis.

    Directory of Open Access Journals (Sweden)

    Cesar A Ugarte-Gil

    Full Text Available INTRODUCTION: Tuberculosis (TB destroys lung tissues and this immunopathology is mediated in part by Matrix Metalloproteinases (MMPs. There are no data on the relationship between local tissue MMPs concentrations, anti-tuberculosis therapy and sputum conversion. MATERIALS AND METHODS: Induced sputum was collected from 68 TB patients and 69 controls in a cross-sectional study. MMPs concentrations were measured by Luminex array, TIMP concentrations by ELISA and were correlated with a disease severity score (TBscore. 46 TB patients were then studied longitudinally at the 2nd, 8th week and end of treatment. RESULTS: Sputum MMP-1,-2,-3,-8,-9 and TIMP-1 and -2 concentrations are increased in TB. Elevated MMP-1 and -3 concentrations are independently associated with higher TB severity scores (p<0.05. MMP-1, -3 and -8 concentrations decreased rapidly during treatment (p<0.05 whilst there was a transient increase in TIMP-1/2 concentrations at week 2. MMP-2, -8 and -9 and TIMP-2 concentrations were higher at TB diagnosis in patients who remain sputum culture positive at 2 weeks and MMP-3, -8 and TIMP-1 concentrations were higher in these patients at 2nd week of TB treatment. CONCLUSIONS: MMPs are elevated in TB patients and associate with disease severity. This matrix-degrading phenotype resolves rapidly with treatment. The MMP profile at presentation correlates with a delayed treatment response.

  12. Clinical characteristic, diagnosis and effectiveness of treatment of tuberculosis in HIV-infected patients in the Saratov region

    Directory of Open Access Journals (Sweden)

    T. I. Morozova

    2016-01-01

    Full Text Available Aim: evaluate the clinical manifestations, efficacy of microbiologicaldiagnosis and results of treatment of patients with tuberculosis (TB in combination with HIV (TB/HIV, residing in the territory of the Saratov region.Materials and methods: analyzed the medical records (hospital records, medical history, personal record cards TB/HIV, 130 patients coinfected with TB/HIV who were on treatment in TB facilities of Saratov region in 2014.Results: it was found that the combination of TB and HIV infection was more common in men (71,5% aged 30–39 years, mostly (75,4% residents of large cities. TB in 64,6% of cases develop on the background of existing HIV infection with disease duration from 1 to 18 years. The dominant forms of TB were infiltrative – 50,8% and disseminated – 25,4% with high levels of multidrug resistance (MDR – 25% and polyresistance – 17,3%. Efficiency a course of treatment of ТВ which was completed in 2014 year amounted to 41,5% and was higher in the group of patients in which treatment with anti-tuberculosis therapy is used antiretroviral therapy (ARVT – 49,3% versus 30,9% without ARVT, p = 0,0416. It was found increase of CD4 cell counts after treatment in patients TB/HIV, which, together with anti-tuberculosis therapy received ARVT 301 ± 45 cells/microliter vs. 202,3 ± 32 cells/microliter in patients without ARVT, p=0,0416.Conclusion: determined that TB in patients with HIV infection characterized by severe course of the process with low efficiency of treatment and high MDR, which requires the strengthening of measures to control the spread of TB in these patients. 

  13. The Statistical Relevance and Effect of Assuming Pessimistic Default Overall Thermal Transmittance Coefficients on Dwelling Energy Performance Certification Quality in Ireland

    OpenAIRE

    Ahern, Ciara; Norton, Brian; ENRIGHT, Bernard

    2016-01-01

    In the EU, Energy Performance Certificates (EPCs) are issued for dwellings whenever they are constructed, sold or leased. Where requiring data would be prohibitively costly, nationally applicable default-values for the thermal transmittance coefficients of the building envelope are employed. Use of such worst case default U-values ensure that a poor dwelling does not attain a better energy rating than is merited. In the absence of empirical data in Ireland thermal-default U-values, as in many...

  14. Loss given default determinants in a commercial bank lending: an emerging market case study

    Directory of Open Access Journals (Sweden)

    Jure Poljšak

    2010-06-01

    Full Text Available The purpose of this paper is to analyse the loss given default (LGD determinants in case of a typical loan portfolio consisting of SME loans in a commercial bank operating in one of the quickly developing banking markets, i.e. in Slovenia. Accurate LGD estimates of defaulted bank claims are important for provisioning reserves for credit losses, calculating adequate risk capital and determining fair pricing risky bank loans. While most of the empirical literature in the field concentrates on corporate bond markets to estimate losses in the event of default, we use a unique individual bank data set on SME loan losses. Due to the proprietary nature of data only few studies of this kind have been published so far and to our knowledge none of them covers the Eastern European banking markets. In the first stage of the analysis we estimate the LGD variable by applying the discounted cash flow approach, while in the second stage we analyse its determinants by using the ordinal regression analysis. Our findings suggest that reliable LGD estimates can be produced by discounting expected loan related future cash flows and that explanatory factors, such as type of collateral, type of industrial sector, last available loan rating, size of the debt and loan maturity satisfactorily explicate variability of the LGD variable in the specific banking market. All the results are not only relevant to the impairment policy determination and capital adequacy calculation in the specific bank, but also to the evaluation of SME loans characteristics in developing markets.

  15. The Increasing Default Risk of U.S. Treasuries Securities Due to the Financial Crisis

    OpenAIRE

    Srinivas Nippani; Smith, Stanley D.

    2009-01-01

    We examine the impact of the current financial crisis on long-term U.S. Treasury yields by testing the impact of a series of events from December 2007 to March 2009 on the spread between 10-year United States Dollar (USD) London Interbank Offered Rate (LIBOR) swap and 10-year U.S. Treasury (constant maturity) rates to measure risk associated with Treasuries. Controlling for the liquidity of the two markets, the default risk of the swap, and the net foreign purchases of Treasury securities, we...

  16. "Banks Running Wild--The Subversion of Insurance by "Life Settlements" and Credit Default Swaps"

    OpenAIRE

    Marshall Auerback; L. Randall Wray

    2009-01-01

    Oblivious to any lessons that might have been learned from the global financial mess it has created, Wall Street is looking for the next asset bubble. Perhaps in the market for death it has found a replacement for the collapsed markets in subprime mortgage–backed securities and credit default swaps (CDSs). Instead of making bets on the "death" of securities, this new product will allow investors to gamble on the death of human beings by purchasing "life settlements"--life insurance policies t...

  17. The fundamental theorem of asset pricing under default and collateral in finite discrete time

    Science.gov (United States)

    Alvarez-Samaniego, Borys; Orrillo, Jaime

    2006-08-01

    We consider a financial market where time and uncertainty are modeled by a finite event-tree. The event-tree has a length of N, a unique initial node at the initial date, and a continuum of branches at each node of the tree. Prices and returns of J assets are modeled, respectively, by a R2JxR2J-valued stochastic process . In this framework we prove a version of the Fundamental Theorem of Asset Pricing which applies to defaultable securities backed by exogenous collateral suffering a contingent linear depreciation.

  18. Benchmark Simulation Model No 2 – finalisation of plant layout and default control strategy

    DEFF Research Database (Denmark)

    Nopens, I.; Benedetti, L.; Jeppsson, U.;

    2010-01-01

    The COST/IWA Benchmark Simulation Model No 1 (BSM1) has been available for almost a decade. Its primary purpose has been to create a platform for control strategy benchmarking of activated sludge processes. The fact that the research work related to the benchmark simulation models has resulted in...... evaluated in a realistic fashion in the one week BSM1 evaluation period. In this paper, the finalised plant layout is summarised and, as was done for BSM1, a default control strategy is proposed. A demonstration of how BSM2 can be used to evaluate control strategies is also given....

  19. The Psychedelic State Induced by Ayahuasca Modulates the Activity and Connectivity of the Default Mode Network

    OpenAIRE

    Palhano-Fontes, Fernanda; Katia C. Andrade; Tofoli, Luis F.; Antonio C. Santos; Crippa, Jose Alexandre S.; Hallak, Jaime E. C.; Ribeiro, Sidarta; de Araujo, Draulio B.

    2015-01-01

    The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs. A remarkable increase in introspection is at the core of these altered states of consciousness. Self-oriented mental activity has been consistently linked to the Default Mode Network (DMN), a set of brain regions more active during rest than during the execution of a goal-directed task. Here we used fMRI technique to in...

  20. Essays on capital structure, debt maturity, trade credit, and default probability

    OpenAIRE

    Hol, Suzan

    2004-01-01

    To finance investments, a firm needs to decide which sources are to be used to attract funds; that is how the financial structure of the firm should be. The main subjects of this thesis are how the firm’s financial structure is determined and how the chosen financial structure affects the firm’s probability of default. The thesis consists of five essays studying the financial structure of firms and one popular scientific paper on financial behavior.In the first paper, a theoretical model is d...

  1. Discourse norms as default rules: structuring corporate speech to multiple stakeholders.

    Science.gov (United States)

    Yosifon, David G

    2011-01-01

    This Article analyzes corporate speech problems through the framework of corporate law. The focus here is on the "discourse norms" that regulate corporate speech to various corporate stakeholders, including shareholders, workers, and consumers. I argue that these "discourse norms" should be understood as default terms in the "nexus-of-contracts" that comprises the corporation. Having reviewed the failure of corporate law as it bears on the interests of non-shareholding stakeholders such as workers and consumers, I urge the adoption of prescriptive discourse norms as an approach to reforming corporate governance in a socially useful manner. PMID:21847901

  2. OVERVIEW OF THE RELEVANT INDICATORS OF DEFAULTED AND NON-DEFAULTED COMPANIES AND POSSIBILITIES OF IMPROVEMENT FOR THE RATING SYSTEMS USED BY THE ROMANIAN COMMERCIAL BANKS

    Directory of Open Access Journals (Sweden)

    Kovacs Ildiko

    2011-12-01

    Full Text Available Since the beginning of the financial and economic crises many news came to light which discussed the increasing number of non-performing loans, and the fact that as a result of the company break-downs, the bank portfolios have also gone worse and worse. In this paper our goal is to find out which internal factors influence the solvency of a company, therefore, to point out the weaknesses of the current Romanian rating systems, which as we will see, do not take into only relevant criteria when according a loan to a company. In order to conduct this study, we choose 18 indicators from several categories to predict bankruptcy. Some of the indicators mentioned above are really common in the international and the Romanian literature (e.g. ROA, ROE, ROS, assets turnover ratio, some of them are less. On a sample of 3000 Romanian companies we use the T-test statistical method to find out if an indicator is significant or not. The sample consists of companies (defaulted and non-defaulted as well which have presented their financial statements (balance, profit and loss account between 1999 and 2008. For each company a set of 18 financial indicators was calculated, but the results obtained show that only 8 of them is significant in predicting bankruptcy: ROA, assets turnover ratio, equity/total assets, general leverage, current assets to total assets, cash to total assets, total assets and sales. In the next step, by analyzing the obligatory forms used in credit lending, we conclude which indicators are used by different Romanian commercial banks. We found that only four out of seven banks calculate all of the significant indicators identified in the first part of the paper. Finally, we made a proposal about which quantitative indicators should the banks use to minimize the credit losses and to avoid the overdue payments. In addition, we consider that the banks should pay attention to the qualitative factors as well to effectively filter out non

  3. Task-dependent modulation of effective connectivity within the default mode network

    Directory of Open Access Journals (Sweden)

    BaojuanLi

    2012-06-01

    Full Text Available The default mode network (DMN has recently attracted widespread interest. Previous studies have found that task related processing can induce deactivation and changes in the functional connectivity of this network. However, it remains unclear how tasks modulate the underlying effective connectivity within the DMN. Using recent advances in Dynamic Causal Modeling (DCM, we study the effective connectivity of resting state networks. The current fMRI study investigated the modulatory effect of (gender judgment task performance on directed connectivity within the DMN. Sixteen healthy subjects were scanned twice: at rest and while performing a gender judgment task. Group independent component analysis was used to decompose the functional images into spatial independent components. Four subject-specific regions of interest (ROIs were defined according to the ensuing default mode component: the posterior cingulate cortex, the left lateral parietal cortex, the right lateral parietal cortex and the medial prefrontal cortex. Effective connectivity among these regions was then characterized with stochastic DCM, revealing enhanced (extrinsic between region connectivity within the DMN during task sessions – and a universal decrease in (intrinsic self inhibition – relative to resting sessions. These results suggest a distributed but systematic modulatory effect of cognitive and attentional set on the effective connectivity subtending the DMN: an effect that increases its sensitivity to inputs and may optimize distributed processing during task performance.

  4. Resting-state functional connectivity of the default mode network associated with happiness.

    Science.gov (United States)

    Luo, Yangmei; Kong, Feng; Qi, Senqing; You, Xuqun; Huang, Xiting

    2016-03-01

    Happiness refers to people's cognitive and affective evaluation of their life. Why are some people happier than others? One reason might be that unhappy people are prone to ruminate more than happy people. The default mode network (DMN) is normally active during rest and is implicated in rumination. We hypothesized that unhappiness may be associated with increased default-mode functional connectivity during rest, including the medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC) and inferior parietal lobule (IPL). The hyperconnectivity of these areas may be associated with higher levels of rumination. One hundred forty-eight healthy participants underwent a resting-state fMRI scan. A group-independent component analysis identified the DMNs. Results indicated increased functional connectivity in the DMN was associated with lower levels of happiness. Specifically, relative to happy people, unhappy people exhibited greater functional connectivity in the anterior medial cortex (bilateral MPFC), posterior medial cortex regions (bilateral PCC) and posterior parietal cortex (left IPL). Moreover, the increased functional connectivity of the MPFC, PCC and IPL, correlated positively with the inclination to ruminate. These results highlight the important role of the DMN in the neural correlates of happiness, and suggest that rumination may play an important role in people's perceived happiness. PMID:26500289

  5. Diagnostic classification of intrinsic functional connectivity highlights somatosensory, default mode, and visual regions in autism

    Directory of Open Access Journals (Sweden)

    Colleen P. Chen

    2015-01-01

    Full Text Available Despite consensus on the neurological nature of autism spectrum disorders (ASD, brain biomarkers remain unknown and diagnosis continues to be based on behavioral criteria. Growing evidence suggests that brain abnormalities in ASD occur at the level of interconnected networks; however, previous attempts using functional connectivity data for diagnostic classification have reached only moderate accuracy. We selected 252 low-motion resting-state functional MRI (rs-fMRI scans from the Autism Brain Imaging Data Exchange (ABIDE including typically developing (TD and ASD participants (n = 126 each, matched for age, non-verbal IQ, and head motion. A matrix of functional connectivities between 220 functionally defined regions of interest was used for diagnostic classification, implementing several machine learning tools. While support vector machines in combination with particle swarm optimization and recursive feature elimination performed modestly (with accuracies for validation datasets <70%, diagnostic classification reached a high accuracy of 91% with random forest (RF, a nonparametric ensemble learning method. Among the 100 most informative features (connectivities, for which this peak accuracy was achieved, participation of somatosensory, default mode, visual, and subcortical regions stood out. Whereas some of these findings were expected, given previous findings of default mode abnormalities and atypical visual functioning in ASD, the prominent role of somatosensory regions was remarkable. The finding of peak accuracy for 100 interregional functional connectivities further suggests that brain biomarkers of ASD may be regionally complex and distributed, rather than localized.

  6. A default mode of brain function in altered states of consciousness.

    Science.gov (United States)

    Guldenmund, P; Vanhaudenhuyse, A; Boly, M; Laureys, S; Soddu, A

    2012-01-01

    Using modern brain imaging techniques, new discoveries are being made concerning the spontaneous activity of the brain when it is devoid of attention-demanding tasks. Spatially separated patches of neuronal assemblies have been found to show synchronized oscillatory activity behavior and are said to be functionally connected. One of the most robust of these is the default mode network, which is associated with intrinsic processes like mind wandering and self-projection. Furthermore, activity in this network is anticorrelated with activity in a network that is linked to attention to external stimuli. The integrity of both networks is disturbed in altered states of consciousness, like sleep, general anesthesia and hypnosis. In coma and related disorders of consciousness, encompassing the vegetative state (unresponsive wakefulness syndrome) and minimally conscious state, default mode network integrity correlates with the level of remaining consciousness, offering the possibility of using this information for diagnostic and prognostic purposes. Functional brain imaging is currently being validated as a valuable addition to the standardized behavioral assessments that are already in use. PMID:23165872

  7. Definition and characterization of an extended social-affective default network.

    Science.gov (United States)

    Amft, Maren; Bzdok, Danilo; Laird, Angela R; Fox, Peter T; Schilbach, Leonhard; Eickhoff, Simon B

    2015-03-01

    Recent evidence suggests considerable overlap between the default mode network (DMN) and regions involved in social, affective and introspective processes. We considered these overlapping regions as the social-affective part of the DMN. In this study, we established a robust mapping of the underlying brain network formed by these regions and those strongly connected to them (the extended social-affective default network). We first seeded meta-analytic connectivity modeling and resting-state analyses in the meta-analytically defined DMN regions that showed statistical overlap with regions associated with social and affective processing. Consensus connectivity of each seed was subsequently delineated by a conjunction across both connectivity analyses. We then functionally characterized the ensuing regions and performed several cluster analyses. Among the identified regions, the amygdala/hippocampus formed a cluster associated with emotional processes and memory functions. The ventral striatum, anterior cingulum, subgenual cingulum and ventromedial prefrontal cortex formed a heterogeneous subgroup associated with motivation, reward and cognitive modulation of affect. Posterior cingulum/precuneus and dorsomedial prefrontal cortex were associated with mentalizing, self-reference and autobiographic information. The cluster formed by the temporo-parietal junction and anterior middle temporal sulcus/gyrus was associated with language and social cognition. Taken together, the current work highlights a robustly interconnected network that may be central to introspective, socio-affective, that is, self- and other-related mental processes. PMID:24399179

  8. Prestimulus default mode activity influences depth of processing and recognition in an emotional memory task.

    Science.gov (United States)

    Soravia, Leila M; Witmer, Joëlle S; Schwab, Simon; Nakataki, Masahito; Dierks, Thomas; Wiest, Roland; Henke, Katharina; Federspiel, Andrea; Jann, Kay

    2016-03-01

    Low self-referential thoughts are associated with better concentration, which leads to deeper encoding and increases learning and subsequent retrieval. There is evidence that being engaged in externally rather than internally focused tasks is related to low neural activity in the default mode network (DMN) promoting open mind and the deep elaboration of new information. Thus, reduced DMN activity should lead to enhanced concentration, comprehensive stimulus evaluation including emotional categorization, deeper stimulus processing, and better long-term retention over one whole week. In this fMRI study, we investigated brain activation preceding and during incidental encoding of emotional pictures and on subsequent recognition performance. During fMRI, 24 subjects were exposed to 80 pictures of different emotional valence and subsequently asked to complete an online recognition task one week later. Results indicate that neural activity within the medial temporal lobes during encoding predicts subsequent memory performance. Moreover, a low activity of the default mode network preceding incidental encoding leads to slightly better recognition performance independent of the emotional perception of a picture. The findings indicate that the suppression of internally-oriented thoughts leads to a more comprehensive and thorough evaluation of a stimulus and its emotional valence. Reduced activation of the DMN prior to stimulus onset is associated with deeper encoding and enhanced consolidation and retrieval performance even one week later. Even small prestimulus lapses of attention influence consolidation and subsequent recognition performance. PMID:26663662

  9. Hawkes-diffusion process and the conditional probability of defaults in the Eurozone

    Science.gov (United States)

    Kim, Jungmu; Park, Yuen Jung; Ryu, Doojin

    2016-05-01

    This study examines market information embedded in the European sovereign CDS (credit default swap) market by analyzing the sovereign CDSs of 13 Eurozone countries from January 1, 2008, to February 29, 2012, which includes the recent Eurozone debt crisis period. We design the conditional probability of defaults for the CDS prices based on the Hawkes-diffusion process and obtain the theoretical prices of CDS indexes. To estimate the model parameters, we calibrate the model prices to empirical prices obtained from individual sovereign CDS term structure data. The estimated parameters clearly explain both cross-sectional and time-series data. Our empirical results show that the probability of a huge loss event sharply increased during the Eurozone debt crisis, indicating a contagion effect. Even countries with strong and stable economies, such as Germany and France, suffered from the contagion effect. We also find that the probability of small events is sensitive to the state of the economy, spiking several times due to the global financial crisis and the Greek government debt crisis.

  10. Fiscally Unsustainable Social Welfare, Untenable Housing Solutions and the Mortgage Default Ratio in South Africa

    Directory of Open Access Journals (Sweden)

    Vuyisani Vuyisani Moss

    2013-10-01

    Full Text Available This article reflects on social welfare system and governance of housingmarkets from an end-user perspective. The article critically analyses the wayin which social welfare has correlated to unsustainable development and createdself entitlement behaviours and attitudes in the South African low incomehousing market.  The phenomenon wasdemonstrable by empirical research whose findings confirmed an existence of anassociation between a fully subsidized social housing model (as underpinned bySouth Africa’s social welfare and propensity to default on mortgages.  The study found that the risk of default byhomeowners in the low income housing market in South Africa is influenced bygovernment’s housing grant model. In other words, the research established thatthe principle of servicing a mortgaged starter property (that is almost similarto a government free house by both structure and design is not universallyaccepted by homeowners of these mortgaged houses.  The unintended consequences are that thesystem has created indefinite expectations that potentially could; (i erodethe country’s balance sheet; (ii add to non-payment behaviour; (iii pressurizethe economic and credit systems; (iv propagate entitlement attitudes andmindsets; (v create social instability and (v widened the country’s balanceof payment deficits.

  11. Enhanced default mode network connectivity with ventral striatum in subthreshold depression individuals.

    Science.gov (United States)

    Hwang, J W; Xin, S C; Ou, Y M; Zhang, W Y; Liang, Y L; Chen, J; Yang, X Q; Chen, X Y; Guo, T W; Yang, X J; Ma, W H; Li, J; Zhao, B C; Tu, Y; Kong, J

    2016-05-01

    Subthreshold depression (StD) is a highly prevalent condition associated with increased service utilization and social morbidity. Nevertheless, due to limitations in current diagnostic systems that set the boundary for major depressive disorder (MDD), very few brain imaging studies on the neurobiology of StD have been carried out, and its underlying neurobiological mechanism remains unclear. In recent years, accumulating evidence suggests that the disruption of the default mode network (DMN), a network involved in self-referential processing, affective cognition, and emotion regulation, is involved in major depressive disorder. Using independent component analysis, we investigated resting-state default mode network (DMN) functional connectivity (FC) changes in two cohorts of StD patients with different age ranges (young and middle-aged, n = 57) as well as matched controls (n = 79). We found significant FC increase between the DMN and ventral striatum (key region in the reward network), in both cohorts of StD patients in comparison with controls. In addition, we also found the FC between the DMN and ventral striatum was positively and significantly associated with scores on the Center for Epidemiologic Studies Depression Scale (CES-D), a measurement of depressive symptomatology. We speculate that this enhanced FC between the DMN and the ventral striatum may reflect a self-compensation to ameliorate the lowered reward function. PMID:26922247

  12. Is there Needed an Industry Approach on Corporate Default Risk? Case Study on Companies Listed on Romanian Stock Exchange

    Directory of Open Access Journals (Sweden)

    Cristina Maria Triandafil

    2009-02-01

    Full Text Available This paper focuses on applying Black and Scholes structural approach on credit risk in the case of the companies listed on Romanian Stock Exchange. We conduct a case-study on 35 companies belonging to five industries (energetic, materials, chemistry, pharmaceuticals, equipments during a period of 10 years in order to highlight out default point/threshold and its essential factors evolution across industries. Research approach is concentrated also on the specific characteristics of the Romanian capital market (especially in terms of illiquidity and lack of transparency additional costs, macroeconomic environment and corporate finance decision process. We compute default point from the perspective of the arbitrage between assets and leverage; in accordance with the most recent theories on specific features corporate default within emerging countries (Galytskyy, 2006, a key element will be represented by the assets volatility which will be correlated with the country risk premium in order to highlight out a potential macroeconomic impact on corporate failure.

  13. A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience

    Directory of Open Access Journals (Sweden)

    Ravinder eJerath

    2015-08-01

    Full Text Available The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information is filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system.

  14. GAO's Views on the Default Task Force's Recommendations for Reducing Default Costs in the Guaranteed Student Loan Program. Testimony before the Subcommittee on Postsecondary Education, Committee on Education and Labor, House of Representatives.

    Science.gov (United States)

    Gainer, William J.

    This General Accounting Office (GAO) testimony before the Subcommittee on Postsecondary Education, Committee on Education and Labor, House of Representatives, concerns the findings of the task force that addressed the increasing costs of student loan defaults. The task force report is considered, generally, to provide additional incentives and…

  15. The procurement landscape of pediatric tuberculosis treatment: a Global Drug Facility perspective.

    Science.gov (United States)

    Scott, C; Gardiner, E; de Lucia, A

    2015-12-01

    Simple, quality-assured, child-friendly formulations of existing first-line anti-tuberculosis (TB) drugs in the correct dosages are now becoming available. Efforts are currently underway by the TB Alliance, the World Health Organization (WHO), and its partners to make appropriate medicines available to treat children diagnosed with TB. The functioning of the current market and the distribution pathways in pediatric TB drugs now require characterization and understanding in order to develop appropriate strategies for delivery of these and other future pediatric TB medicines. The Stop TB Partnership's Global Drug Facility (GDF) plays a major role in supplying pediatric TB medications worldwide. GDF is considered to be the largest procurer of pediatric TB treatment and the largest supplier to national TB programs of quality pediatric drugs. Between 2007 and 2013, the GDF delivered more than 580, 000 treatments to children in over 50 countries, 14 of which are among the 22 high TB burden countries. We analyzed this data set in the context of WHO estimates of pediatric TB as well as other available information to assess the functioning of the current market, lessons learnt from the GDF experience in the market, and opportunities for future products. PMID:26564536

  16. Short-course treatment for multidrug-resistant tuberculosis: the STREAM trials.

    Science.gov (United States)

    Moodley, Riya; Godec, Thomas R

    2016-03-01

    Multidrug-resistant (MDR) tuberculosis (TB) is a threat to global TB control, as suboptimal and poorly tolerated treatment options have resulted in largely unfavourable outcomes for these patients. The last of six cohort studies conducted in Bangladesh which assessed a new shorter regimen using currently available TB drugs showed promising results and offered the possibility of a more acceptable and more effective regimen than the one recommended by the World Health Organization (WHO). The aims of stage 1 of the STREAM (Evaluation of a Standardised Treatment Regimen of Anti-tuberculosis Drugs for Patients with Multidrug-resistant Tuberculosis) trial are to evaluate the efficacy and safety of this regimen, compared to the current WHO-recommended standard of care. Stage 2 evaluates two new bedaquiline-containing regimens: one an all-oral regimen and the second a further shortened and simplified version of the stage 1 study regimen, comparing the efficacy and safety of each to that of the stage 1 study regimen and also to the WHO-recommended standard of care. Success of the stage 1 study regimen would in all probability provide a new standard of care for MDR-TB patients, while positive results from the bedaquiline-containing regimens in stage 2 may allow for even greater progress in the management of this difficult population. PMID:26929418

  17. Short-course treatment for multidrug-resistant tuberculosis: the STREAM trials

    Directory of Open Access Journals (Sweden)

    Riya Moodley

    2016-03-01

    Full Text Available Multidrug-resistant (MDR tuberculosis (TB is a threat to global TB control, as suboptimal and poorly tolerated treatment options have resulted in largely unfavourable outcomes for these patients. The last of six cohort studies conducted in Bangladesh which assessed a new shorter regimen using currently available TB drugs showed promising results and offered the possibility of a more acceptable and more effective regimen than the one recommended by the World Health Organization (WHO. The aims of stage 1 of the STREAM (Evaluation of a Standardised Treatment Regimen of Anti-tuberculosis Drugs for Patients with Multidrug-resistant Tuberculosis trial are to evaluate the efficacy and safety of this regimen, compared to the current WHO-recommended standard of care. Stage 2 evaluates two new bedaquiline-containing regimens: one an all-oral regimen and the second a further shortened and simplified version of the stage 1 study regimen, comparing the efficacy and safety of each to that of the stage 1 study regimen and also to the WHO-recommended standard of care. Success of the stage 1 study regimen would in all probability provide a new standard of care for MDR-TB patients, while positive results from the bedaquiline-containing regimens in stage 2 may allow for even greater progress in the management of this difficult population.

  18. A compilation of radionuclide transfer factors for the plant, meat, milk, and aquatic food pathways and the suggested default values for the RESRAD code

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.Y.; Biwer, B.M.; Yu, C.

    1993-08-01

    The ongoing development and revision of the RESRAD computer code at Argonne National Laboratory requires update of radionuclide transfer factors for the plant, meat, milk, and aquatic food pathways. Default values for these transfer factors used in published radiological assessment reports are compiled and compared with values used in RESRAD. The differences among the reported default values used in different radiological assessment codes and reports are also discussed. In data comparisons, values used in more recent reports are given more weight because more recent experimental work tends to be conducted under better-defined laboratory or field conditions. A new default value is suggested for RESRAD if one of the following conditions is met: (1) values used in recent reports are an order of magnitude higher or lower than the default value currently used in RESRAD, or (2) the same default value is used in several recent radiological assessment reports.

  19. Optimal pricing of default customers in electrical distribution systems: Effect behavior performance of demand response models

    International Nuclear Information System (INIS)

    The response of a non-linear mathematical model is analyzed for the calculation of the optimal prices for electricity assuming default customers under different scenarios and using five different mathematical functions for the consumer response: linear, hyperbolic, potential, logarithmic and exponential. The mathematical functions are defined to simulate the hourly changes in the consumer response according to the load level, the price of electricity, and also depending on the elasticity at every hour. The behavior of the optimization model is evaluated separately under two different objective functions: the profit of the electric utility and the social welfare. The optimal prices as well as the served load are calculated for two different operation schemes: in an hourly basis and also assuming a single constant price for the 24 h of the day. Results obtained by the optimization model are presented and compared for the five different consumer load functions. (author)

  20. Default and rational persuasion of the judge Revelia e persuasão racional do juiz

    Directory of Open Access Journals (Sweden)

    Lourival José de Oliveira

    2005-12-01

    Full Text Available It checks the borders of the presumption of facts contained in the initial petition when lacks seasonable contestation with the observance of legal formalities. Seen as an objective fact, the default will occur when the defendant stays inert at the processual moment offered to him to adduce his reasons to resist the request of the prosecutor, what doesn’t necessary implies in its procedure. However, the default not always unleashes its effects, that are classified as material or processual, consisting in the presumption of the veracity of the facts pleaded by the prosecutor in his initial petition and the lack of need of notification the default for the processual acts that follows. The presumption in default is relative, it means that, its effects circumscribing verisimilar facts and consistent with the other evidences that lie in the lawsuit, what goes to the need of the material direction and not only the formal side by the judge as a way to find the fair composition of the litigation, there so attending the social finalities of the process effectively inserted in the Democratic State of Law. Coming to the conclusion that shall exteriorized in the explaining of the decision the coherence of fatidic bases and juridical ones, containing all the prominent points of the suit, therefore attending the principle of the rational persuasion, resulting in a full jurisdictional tutelage, under the penalty of nullity of the law suit due to the lack of motivation of the sentence.Verifica os limites da presunção dos fatos contidos na petição inicial quando da ausência de contestação tempestiva e com a observância das formalidades legais. Vista como um fato objetivo, a revelia ocorrerá quando o réu queda-se inerte no momento processual em que lhe é facultado aduzir suas razões de resistência à demanda do autor, o que não implica necessariamente na sua procedência. Contudo, a revelia nem sempre desencadeia os seus efeitos, que s

  1. Where Defaults Don't Help the Case of the German Plural System

    CERN Document Server

    Nakisa, R C; Nakisa, Ramin Charles; Hahn, Ulrike

    1996-01-01

    The German plural system has become a focal point for conflicting theories of language, both linguistic and cognitive. We present simulation results with three simple classifiers - an ordinary nearest neighbour algorithm, Nosofsky's `Generalized Context Model' (GCM) and a standard, three-layer backprop network - predicting the plural class from a phonological representation of the singular in German. Though these are absolutely `minimal' models, in terms of architecture and input information, they nevertheless do remarkably well. The nearest neighbour predicts the correct plural class with an accuracy of 72% for a set of 24,640 nouns from the CELEX database. With a subset of 8,598 (non-compound) nouns, the nearest neighbour, the GCM and the network score 71.0%, 75.0% and 83.5%, respectively, on novel items. Furthermore, they outperform a hybrid, `pattern-associator + default rule', model, as proposed by Marcus et al. (1995), on this data set.

  2. A new integrative model of cerebral activation, deactivation and default mode function in Alzheimer's disease

    International Nuclear Information System (INIS)

    Functional imaging methods such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) allow in vivo assessment of cerebral metabolism at rest and cerebral responses to cognitive stimuli. Activation studies with different cognitive tasks have deepened the understanding of underlying pathology leading to Alzheimer disease (AD) and how the brain reacts to and potentially compensates the imposed damage inflicted by this disease. The aim of this manuscript study was to summarize current findings of activation studies in healthy people at risk for AD, in people with mild cognitive impairment (MCI) as a possible progenitor of AD and finally in patients with manifest AD, adding recent results about impaired deactivation abilities and default mode function in AD. A new comprehensive model will be introduced integrating these heterogeneous findings and explaining their impact on cognitive performance. (orig.)

  3. Default Mode Network Activity Predicts Early Memory Decline in Healthy Young Adults Aged 18-31.

    Science.gov (United States)

    Nelson, Steven M; Savalia, Neil K; Fishell, Andrew K; Gilmore, Adrian W; Zou, Fan; Balota, David A; McDermott, Kathleen B

    2016-08-01

    Functional magnetic resonance imaging (fMRI) research conducted in healthy young adults is typically done with the assumption that this sample is largely homogeneous. However, studies from cognitive psychology suggest that long-term memory and attentional control begin to diminish in the third decade of life. Here, 100 participants between the ages of 18 and 31 learned Lithuanian translations of English words in an individual differences study using fMRI. Long-term memory ability was operationalized for each participant by deriving a memory score from 3 convergent measures. Age of participant predicted memory score in this cohort. In addition, degree of deactivation during initial encoding in a set of regions occurring largely in the default mode network (DMN) predicted both age and memory score. The current study demonstrates that early memory decline may partially be accounted for by failure to modulate activity in the DMN. PMID:26209847

  4. Impaired language function in generalized epilepsy: inadequate suppression of the default mode network.

    Science.gov (United States)

    Gauffin, Helena; van Ettinger-Veenstra, Helene; Landtblom, Anne-Marie; Ulrici, Daniel; McAllister, Anita; Karlsson, Thomas; Engström, Maria

    2013-07-01

    We aimed to study the effect of a potential default mode network (DMN) dysfunction on language performance in epilepsy. Language dysfunction in focal epilepsy has previously been connected to brain damage in language-associated cortical areas. In this work, we studied generalized epilepsy (GE) without focal brain damage to see if the language function was impaired. We used functional magnetic resonance imaging (fMRI) to investigate if the DMN was involved. Eleven persons with GE and 28 healthy controls were examined with fMRI during a sentence-reading task. We demonstrated impaired language function, reduced suppression of DMN, and, specifically, an inadequate suppression of activation in the left anterior temporal lobe and the posterior cingulate cortex, as well as an aberrant activation in the right hippocampal formation. Our results highlight the presence of language decline in people with epilepsy of not only focal but also generalized origin. PMID:23648277

  5. Coactivation of the Default Mode Network regions and Working Memory Network regions during task preparation.

    Science.gov (United States)

    Koshino, Hideya; Minamoto, Takehiro; Yaoi, Ken; Osaka, Mariko; Osaka, Naoyuki

    2014-01-01

    The Default Mode Network (DMN) regions exhibit deactivation during a wide variety of resource demanding tasks. However, recent brain imaging studies reported that they also show activation during various cognitive activities. In addition, studies have found a negative correlation between the DMN and the working memory network (WMN). Here, we investigated activity in the DMN and WMN regions during preparation and execution phases of a verbal working memory task. Results showed that the core DMN regions, including the medial prefrontal cortex and posterior cingulate cortex, and WMN regions were activated during preparation. During execution, however, the WMN regions were activated but the DMN regions were deactivated. The results suggest that activation of these network regions is affected by allocation of attentional resources to the task relevant regions due to task demands. This study extends our previous results by showing that the core DMN regions exhibit activation during task preparation and deactivation during task execution. PMID:25092432

  6. PTEN: a default gate-keeping tumor suppressor with a versatile tail

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The tumor suppressor PTEN controls a variety of biological processes including cell proliferation, growth, migration, and death. As a master cellular regulator, PTEN itself is also subjected to deliberated regulation to ensure its proper function. Defects in PTEN regulation have a profound impact on carcinogenesis. In this review, we briefly discuss recent advances concerning PTEN regulation and how such knowledge facilitates our understanding and further exploration of PTEN biology. The carboxyl-tail of PTEN, which appears to be associated with multiple types of posttranslational regulation, will be under detailed scrutiny. Further, a comparative analysis of PTEN and p53 suggests while p53 needs to be activated to suppress tumorigenesis (a dormant gatekeeper), PTEN is probably a constitutive surveillant against cancer development, thus a default gatekeeper.

  7. Acupuncture Modulates the Functional Connectivity of the Default Mode Network in Stroke Patients

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2014-01-01

    Full Text Available Abundant evidence from previous fMRI studies on acupuncture has revealed significant modulatory effects at widespread brain regions. However, few reports on the modulation to the default mode network (DMN of stroke patients have been investigated in the field of acupuncture. To study the modulatory effects of acupuncture on the DMN of stroke patients, eight right hemispheric infarction and stable ischemic stroke patients and ten healthy subjects were recruited to undergo resting state fMRI scanning before and after acupuncture stimulation. Functional connectivity analysis was applied with the bilateral posterior cingulate cortices chosen as the seed regions. The main finding demonstrated that the interregional interactions between the ACC and PCC especially enhanced after acupuncture at GB34 in stroke patients, compared with healthy controls. The results indicated that the possible mechanisms of the modulatory effects of acupuncture on the DMN of stroke patients could be interpreted in terms of cognitive ability and motor function recovery.

  8. Case against Diagnosing Developmental Language Disorder by Default: A Single Case Study of Acquired Aphasia Associated with Convulsive Disorder

    Science.gov (United States)

    Marinac, Julie V.; Harper, Laura

    2009-01-01

    The aim of this article is to inform the diagnostic knowledge base for professionals working in the field of language disorders when classic symptoms, characteristics and sequences are not found. The information reveals the risk of diagnosis with a developmental language disorder (DLD) by default when no underlying cause can be readily identified.…

  9. Short-term antidepressant administration reduces default mode and task-positive network connectivity in healthy individuals during rest

    NARCIS (Netherlands)

    van Wingen, Guido A; Tendolkar, Indira; Urner, Maren; van Marle, Hein J; Denys, D.; Verkes, Robbert-Jan; Fernández, Guillén

    2014-01-01

    Resting-state studies in depressed patients have revealed increased connectivity within the default mode network (DMN) and task-positive network (TPN). This has been associated with heightened rumination, which is the tendency to repetitively think about symptoms of distress. Here, we performed a ph

  10. Studying Cultural Default of Subtitle Translation Based on Relevance Theory:A Case Study of White Collar

    Institute of Scientific and Technical Information of China (English)

    褚杨杨; 李梦

    2015-01-01

    Relevance theory as a new kind of language cognition model theory features of strong practicability and maneuverability. Cultural differences between China and western country wil inevitably contribute to cultural default. Therefore, the introducing of the relevance theory in subtitles translation, can effectively improve the translation accuracy and vitality of the expression.

  11. 7 CFR 4290.1810 - Events of default and the Secretary's remedies for RBIC's noncompliance with terms of Debentures.

    Science.gov (United States)

    2010-01-01

    ... the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE RURAL BUSINESS INVESTMENT COMPANY (âRBICâ) PROGRAM RBIC's Noncompliance... 7 Agriculture 15 2010-01-01 2010-01-01 false Events of default and the Secretary's remedies...

  12. Deriving Default Dermal Exposure Values for Use in a Risk Assessment Toolkit for Small and Medium-sized Enterprises

    NARCIS (Netherlands)

    Warren, N.; Goede, H.A.; Tijssen, S.C.H.A.; Oppl, R.; Schipper, H.J.; Hemmen, J.J. van

    2003-01-01

    This paper describes the derivation of default task-based dermal exposure values for use in a risk assessment toolkit for small and medium-sized enterprises (SMEs). A set of separately determined dermal exposure modifiers have been applied to published studies of dermal exposure to obtain 'normalize

  13. Prediction of delayed treatment response in pulmonary tuberculosis: use of time to positivity values of Bactec cultures.

    Science.gov (United States)

    Carroll, N M; Uys, P; Hesseling, A; Lawrence, K; Pheiffer, C; Salker, F; Duncan, K; Beyers, N; van Helden, P D

    2008-11-01

    New drugs that can shorten tuberculosis (TB) treatment and target drug resistant strains are urgently needed. A test which could predict patients at risk of a delayed response to treatment would facilitate clinical trials of new anti-tuberculosis drugs. A widely-used test for the assessment of response to treatment is sputum smear examination. Patients who are smear positive after 2 and 3 months of treatment are said to have delayed and significantly delayed treatment responses respectively. Time to positivity (TTP) values of Bactec cultures, from the first 2 weeks of treatment were used to predict delayed and significantly delayed treatment responses in patients with first time pulmonary tuberculosis. Changes in TTP values early in treatment were transformed to a response ratio (r). Values of r that were less than a threshold value (r(c)) indicated patients who were at risk of having delayed or significantly delayed response to treatment. Accuracy of prediction was sensitive to the timing of sputum sampling and adherence to therapy in the first 2 weeks. Based on TTP data from the first 2 weeks of treatment, significantly delayed treatment response could be predicted with a sensitivity of 75% and a specificity of 62% while the positive (PPV) and negative predictive values (NPV) were 14% and 97% respectively. While the high NPV indicates that a large proportion of patients with a satisfactory response to treatment can be reliably identified, the low PPV value underlines the need to use TTP in conjunction with other markers of disease activity to predict unfavourable treatment response in tuberculosis treatment. PMID:18456556

  14. The roles of reward, default, and executive control networks in set-shifting impairments in schizophrenia.

    Directory of Open Access Journals (Sweden)

    James A Waltz

    Full Text Available Patients with schizophrenia (SZ show deficits on tasks of rapid reinforcement learning, like probabilistic reversal learning (PRL, but the neural bases for those impairments are not known. Recent evidence of relatively intact sensitivity to negative outcomes in the ventral striatum (VS in many SZ patients suggests that PRL deficits may be largely attributable to processes downstream from feedback processing, involving both the activation of executive control task regions and deactivation of default mode network (DMN components. We analyzed data from 29 chronic SZ patients and 21 matched normal controls (NCs performing a PRL task in an MRI scanner. Subjects were presented with eight pairs of fractal stimuli, for 50 trials each. For each pair, subjects learned to choose the more frequently-rewarded (better stimulus. Each time a criterion was reached, the better stimulus became the worse one, and the worse became the better. Responses to feedback events were assessed through whole-brain and regions-of-interest (ROI analyses in DMN. We also assessed correlations between BOLD signal contrasts and clinical measures in SZs. Relative to NCs, SZ patients showed comparable deactivation of VS in response to negative feedback, but reduced deactivation of DMN components including medial prefrontal cortex (mPFC. The magnitudes of patients' punishment-evoked deactivations in VS and ventromedial PFC correlated significantly with clinical ratings for avolition/anhedonia. These findings suggest that schizophrenia is associated with a reduced ability to deactivate components of default mode networks, following the presentation of informative feedback and that motivational deficits in SZ relate closely to feedback-evoked activity in reward circuit components. These results also confirm a role for ventrolateral and dorsomedial PFC in the execution of response-set shifts.

  15. Emergentism as a default: cancer as a problem of tissue organization.

    Science.gov (United States)

    Soto, Ana M; Sonnenschein, Carlos

    2005-02-01

    During the last fifty years the dominant stance in experimental biology has been reductionism. For the most part, research programs were based on the notion that genes were in 'the driver's seat' controlling the developmental program and determining normalcy and disease (genetic reductionism and genetic determinism). Philosophers were the first to realize that the belief that the Mendelian genes were reduced to DNA molecules was questionable. Soon after these pronouncements, experimental data confirmed their misgivings. The optimism of molecular biologists, fueled by early success in tackling relatively simple problems, has now been tempered by the difficulties found when attempting to understand complex biological problems. Here, we analyse experimental data that illustrate the shortcomings of this sort of reductionism. We also examine the prevailing paradigm in cancer research, the somatic mutation theory (SMT), the premises of which are: (i) cancer is derived from a single somatic cell that has accumulated multiple DNA mutations; (ii) the default state of cell proliferation in metazoa is quiescence; and (iii) cancer is a disease of cell proliferation caused by mutations in genes that control proliferation and the cell cycle. We challenge the notion that cancer is a cellular problem caused by mutated genes by assessing data gathered both from within the reductionist paradigm and from an alternative view that regards carcinogenesis as a developmental process gone awry. This alternative view, explored under the name of the tissue organization field theory (TOFT), is based on premises that place cancer in a different hierarchical level of complexity from that proposed by the SMT, namely: (i) carcinogenesis represents a problem of tissue organization comparable to organogenesis, and (ii) proliferation is the default state of all cells. We propose that the organicist view, in which the TOFT is based, is a good starting point from which to explore emergent phenomena

  16. Abnormal Default-Mode Network Activation in Cirrhotic Patients: A Functional Magnetic Resonance Imaging Study

    Energy Technology Data Exchange (ETDEWEB)

    Long Jiang Zhang; Guifen Yang; Jianzhong Yin; Yawu Liu; Ji Qi [Dept. of Radiology, Tianjin First Central Hospital, Tianjin Medical Univ., Tianjin (China)

    2007-09-15

    Background: Recently, increasing numbers of studies have demonstrated that, in humans, a default-mode functional network exists in the resting state. Abnormal default-mode network in various diseases has been reported; however, no report concerning hepatic cirrhosis has been published to date. Purpose: To prospectively explore whether the resting-state network in patients with hepatic cirrhosis is abnormal or not, using functional magnetic resonance imaging (fMRI). Material and Methods: 14 patients with hepatic cirrhosis (12 male, two female; 45{+-}9 years) and 14 age- and gender-matched healthy volunteers (12 male, two female; 42{+-}10 years) participated in a blocked-design fMRI study. A modified Stroop task with Chinese characters was used as the target stimulus. Statistical Parametric Mapping 99 software was employed to process the functional data. Individual maps and group data were generated for patients with hepatic cirrhosis and for healthy controls, respectively. Intergroup analysis between patients and healthy controls was also generated using the two-sample t-test model. Cluster analyses were done based on the group data, and an identical P value 0.01 with continuously connected voxels of no less than 10 was defined as significant deactivation. After fMRI scanning was complete, behavioral Stroop interference tests were performed on all subjects; reaction time and error number were recorded. Results: Functionally, deactivation of the posterior cingulate cortex (PCC) and precuneus was absent when subjects performed the incongruous word-reading task; deactivation of the PCC, precuneus, and ventral medial prefrontal cortex was increased when they performed the incongruous color-naming task. Conclusion: The functional as well as behavioral data suggest that cirrhotic patients may have an abnormal deactivation mode. The absence of deactivation in the PCC and precuneus may be a sensitive rather than specific marker in patients with hepatic cirrhosis.

  17. Abnormal Default-Mode Network Activation in Cirrhotic Patients: A Functional Magnetic Resonance Imaging Study

    International Nuclear Information System (INIS)

    Background: Recently, increasing numbers of studies have demonstrated that, in humans, a default-mode functional network exists in the resting state. Abnormal default-mode network in various diseases has been reported; however, no report concerning hepatic cirrhosis has been published to date. Purpose: To prospectively explore whether the resting-state network in patients with hepatic cirrhosis is abnormal or not, using functional magnetic resonance imaging (fMRI). Material and Methods: 14 patients with hepatic cirrhosis (12 male, two female; 45±9 years) and 14 age- and gender-matched healthy volunteers (12 male, two female; 42±10 years) participated in a blocked-design fMRI study. A modified Stroop task with Chinese characters was used as the target stimulus. Statistical Parametric Mapping 99 software was employed to process the functional data. Individual maps and group data were generated for patients with hepatic cirrhosis and for healthy controls, respectively. Intergroup analysis between patients and healthy controls was also generated using the two-sample t-test model. Cluster analyses were done based on the group data, and an identical P value 0.01 with continuously connected voxels of no less than 10 was defined as significant deactivation. After fMRI scanning was complete, behavioral Stroop interference tests were performed on all subjects; reaction time and error number were recorded. Results: Functionally, deactivation of the posterior cingulate cortex (PCC) and precuneus was absent when subjects performed the incongruous word-reading task; deactivation of the PCC, precuneus, and ventral medial prefrontal cortex was increased when they performed the incongruous color-naming task. Conclusion: The functional as well as behavioral data suggest that cirrhotic patients may have an abnormal deactivation mode. The absence of deactivation in the PCC and precuneus may be a sensitive rather than specific marker in patients with hepatic cirrhosis

  18. Neural induction from ES cells portrays default commitment but instructive maturation.

    Directory of Open Access Journals (Sweden)

    Nibedita Lenka

    Full Text Available The neural induction has remained a debatable issue pertaining to whether it is a mere default process or it involves precise instructive cues. We have chosen the embryonic stem (ES cell model to address this issue. In a devised monoculture strategy, the cell-cell interaction availed through optimum cell plating density could define the niche for the attainment of efficient in vitro neurogenesis from the ES cells. The medium plating density was found ideal in generating optimum number of progenitors and also yielded about 80% mature neurons in a serum free culture set up barring any exogenous inducers. We could also demarcate and quantify the neural stem cells/progenitors among the heterogeneous cell population of differentiating ES cells using nestin intron II driven EGFP expression as a tool. The one week post-plating was determined to be the critical time window for optimum neural progenitor generation from ES cells that helped us further in purifying these cells and in demonstrating their proliferation and multipotent differentiation potential. Seeding cells at varying densities, we could decipher an interesting paradoxical scenario that interlinked both commitment and maturation with the initial plating density having a vital influence on neuronal maturation but not specification and the secretory factors were apparently playing a key role during this process. Thus it was comprehended that, the neural specification was a default process independent of exogenous factors and cellular interaction. Conversely, a defined number of cells at the specification stage itself seemed critical to provide an auto-/paracrine means of signaling threshold for the maturation process to materialize.

  19. Systemic BCG-Osis as a Rare Side Effect of Intravesical BCG Treatment for Superficial Bladder Cancer

    Directory of Open Access Journals (Sweden)

    S. Lukacs

    2013-01-01

    Full Text Available Intravesical Bacilli Calmette-Guérin (BCG immunotherapy is a commonly used treatment for superficial bladder cancer. Although the treatment is well tolerated in 95% of cases, life-threatening side effects including BCG sepsis can occur. This report describes the case of an 82-year-old man with a background of lung disease. He developed septic shock and type two respiratory failure after receiving the sixth installation of intravesical BCG (TICE strain immunotherapy for recurrent bladder Transitional Cell Carcinoma in situ. Despite the early initiation of broad spectrum antibiotics (tazocin and gentamicin, he remained pyrexial. There was a rapid deterioration, and on the second day of his admission, he developed type two respiratory failure secondary to Acute Respiratory Distress Syndrome (ARDS prompting transfer to Intensive Care for Bilevel Positive Airway Pressure (BiPAP Ventilation. The blood cultures taken before the induction of antibiotics results were negative. Increasing clinical suspicion of systemic BCG-osis prompted the initiation of antituberculosis therapy (ethambutol, isoniazid rifampicin and steroids. Following six days of BiPAP and anti-tuberculosis therapy in ITU, his condition started to improve. Following a prolonged hospital stay he was discharged on long term ethambutol therapy. BCG-osis is a well-known though rare side effect of intravesical BCG therapy. We would like to highlight the importance of having a low threshold for starting anti-TB treatment.

  20. Systemic BCG-Osis as a Rare Side Effect of Intravesical BCG Treatment for Superficial Bladder Cancer.

    Science.gov (United States)

    Lukacs, S; Tschobotko, B; Szabo, N A; Symes, Andrew

    2013-01-01

    Intravesical Bacilli Calmette-Guérin (BCG) immunotherapy is a commonly used treatment for superficial bladder cancer. Although the treatment is well tolerated in 95% of cases, life-threatening side effects including BCG sepsis can occur. This report describes the case of an 82-year-old man with a background of lung disease. He developed septic shock and type two respiratory failure after receiving the sixth installation of intravesical BCG (TICE strain) immunotherapy for recurrent bladder Transitional Cell Carcinoma in situ. Despite the early initiation of broad spectrum antibiotics (tazocin and gentamicin), he remained pyrexial. There was a rapid deterioration, and on the second day of his admission, he developed type two respiratory failure secondary to Acute Respiratory Distress Syndrome (ARDS) prompting transfer to Intensive Care for Bilevel Positive Airway Pressure (BiPAP) Ventilation. The blood cultures taken before the induction of antibiotics results were negative. Increasing clinical suspicion of systemic BCG-osis prompted the initiation of antituberculosis therapy (ethambutol, isoniazid rifampicin) and steroids. Following six days of BiPAP and anti-tuberculosis therapy in ITU, his condition started to improve. Following a prolonged hospital stay he was discharged on long term ethambutol therapy. BCG-osis is a well-known though rare side effect of intravesical BCG therapy. We would like to highlight the importance of having a low threshold for starting anti-TB treatment. PMID:23844314

  1. Defaults in the Federal Guaranteed Student Loan Programs. Hearing before the Subcommittee on Postsecondary Education of the Committee on Education and Labor, House of Representatives. One Hundredth Congress. Second Session.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    Hearings were conducted to discuss legislation aimed at reducing student loan defaults in the federal Guaranteed Student Loan program. The Student Default Initiative Act of 1988 is designed to address the growing cost of student loan defaults and the increasing imbalance between grant and loan assistance. It develops a procedure to get the…

  2. The default response to uncertainty and the importance of perceived safety in anxiety and stress: An evolution-theoretical perspective.

    Science.gov (United States)

    Brosschot, Jos F; Verkuil, Bart; Thayer, Julian F

    2016-06-01

    From a combined neurobiological and evolution-theoretical perspective, the stress response is a subcortically subserved response to uncertainty that is not 'generated' but 'default': the stress response is 'always there' but as long as safety is perceived, the stress response is under tonic prefrontal inhibition, reflected by high vagally mediated heart rate variability. Uncertainty of safety leads to disinhibiting the default stress response, even in the absence of threat. Due to the stress response's survival value, this 'erring on the side of caution' is passed to us via our genes. Thus, intolerance of uncertainty is not acquired during the life cycle, but is a given property of all living organisms, only to be alleviated in situations of which the safety is learned. When the latter is deficient, generalized unsafety ensues, which underlies chronic anxiety and stress and their somatic health risks, as well as other highly prevalent conditions carrying such risks, including loneliness, obesity, aerobic unfitness and old age. PMID:27259803

  3. Determination of the default curve for the unfolding procedure in the measurement of threshold neutron excitation functions

    Energy Technology Data Exchange (ETDEWEB)

    Jovancevic, Nikola; Daraban, Laura; Oberstedt, Stephan, E-mail: stephan.oberstedt@ec.europa.eu

    2014-03-01

    In this study we have improved the technique for measuring the neutron activation cross-section using wide energy neutron beams (NAXSUN). We propose a method for the determination of the default function for the unfolding procedure, which is an important and critical part for extracting reaction cross-sections from this type of measurements. The new method was tested on the measurement of the excitation function from the threshold energy up to 5.6 MeV for the {sup 113}In(n,n'){sup 113m}In and {sup 115}In(n,n'){sup 115m}In reactions. - Highlights: • Determination of default curve for unfolding procedure solely based on actual measurement. • No input from data libraries or model calculations necessary.

  4. Determination of the default curve for the unfolding procedure in the measurement of threshold neutron excitation functions

    International Nuclear Information System (INIS)

    In this study we have improved the technique for measuring the neutron activation cross-section using wide energy neutron beams (NAXSUN). We propose a method for the determination of the default function for the unfolding procedure, which is an important and critical part for extracting reaction cross-sections from this type of measurements. The new method was tested on the measurement of the excitation function from the threshold energy up to 5.6 MeV for the 113In(n,n')113mIn and 115In(n,n')115mIn reactions. - Highlights: • Determination of default curve for unfolding procedure solely based on actual measurement. • No input from data libraries or model calculations necessary

  5. Altered functional connectivity of the default mode network in Williams syndrome: a multimodal approach.

    Science.gov (United States)

    Sampaio, Adriana; Moreira, Pedro Silva; Osório, Ana; Magalhães, Ricardo; Vasconcelos, Cristiana; Férnandez, Montse; Carracedo, Angel; Alegria, Joana; Gonçalves, Óscar F; Soares, José Miguel

    2016-07-01

    Resting state brain networks are implicated in a variety of relevant brain functions. Importantly, abnormal patterns of functional connectivity (FC) have been reported in several neurodevelopmental disorders. In particular, the Default Mode Network (DMN) has been found to be associated with social cognition. We hypothesize that the DMN may be altered in Williams syndrome (WS), a neurodevelopmental genetic disorder characterized by an unique cognitive and behavioral phenotype. In this study, we assessed the architecture of the DMN using fMRI in WS patients and typically developing matched controls (sex and age) in terms of FC and volumetry of the DMN. Moreover, we complemented the analysis with a functional connectome approach. After excluding participants due to movement artifacts (n = 3), seven participants with WS and their respective matched controls were included in the analyses. A decreased FC between the DMN regions was observed in the WS group when compared with the typically developing group. Specifically, we found a decreased FC in a posterior hub of the DMN including the precuneus, calcarine and the posterior cingulate of the left hemisphere. The functional connectome approach showed a focalized and global increased FC connectome in the WS group. The reduced FC of the posterior hub of the DMN in the WS group is consistent with immaturity of the brain FC patterns and may be associated with the singularity of their visual spatial phenotype. PMID:27412230

  6. The pricing of credit default swaps under a generalized mixed fractional Brownian motion

    Science.gov (United States)

    He, Xinjiang; Chen, Wenting

    2014-06-01

    In this paper, we consider the pricing of the CDS (credit default swap) under a GMFBM (generalized mixed fractional Brownian motion) model. As the name suggests, the GMFBM model is indeed a generalization of all the FBM (fractional Brownian motion) models used in the literature, and is proved to be able to effectively capture the long-range dependence of the stock returns. To develop the pricing mechanics of the CDS, we firstly derive a sufficient condition for the market modeled under the GMFBM to be arbitrage free. Then under the risk-neutral assumption, the CDS is fairly priced by investigating the two legs of the cash flow involved. The price we obtained involves elementary functions only, and can be easily implemented for practical purpose. Finally, based on numerical experiments, we analyze quantitatively the impacts of different parameters on the prices of the CDS. Interestingly, in comparison with all the other FBM models documented in the literature, the results produced from the GMFBM model are in a better agreement with those calculated from the classical Black-Scholes model.

  7. Development of the brain's default mode network from wakefulness to slow wave sleep.

    Science.gov (United States)

    Sämann, Philipp G; Wehrle, Renate; Hoehn, David; Spoormaker, Victor I; Peters, Henning; Tully, Carolin; Holsboer, Florian; Czisch, Michael

    2011-09-01

    Falling asleep is paralleled by a loss of conscious awareness and reduced capacity to process external stimuli. Little is known on sleep-associated changes of spontaneously synchronized anatomical networks as detected by resting-state functional magnetic resonance imaging (rs-fMRI). We employed functional connectivity analysis of rs-fMRI series obtained from 25 healthy participants, covering all non-rapid eye movement (NREM) sleep stages. We focused on the default mode network (DMN) and its anticorrelated network (ACN) that are involved in internal and external awareness during wakefulness. Using independent component analysis, cross-correlation analysis (CCA), and intraindividual dynamic network tracking, we found significant changes in DMN/ACN integrity throughout the NREM sleep. With increasing sleep depth, contributions of the posterior cingulate cortex (PCC)/retrosplenial cortex (RspC), parahippocampal gyrus, and medial prefrontal cortex to the DMN decreased. CCA revealed a breakdown of corticocortical functional connectivity, particularly between the posterior and anterior midline node of the DMN and the DMN and the ACN. Dynamic tracking of the DMN from wakefulness into slow wave sleep in a single subject added insights into intraindividual network fluctuations. Results resonate with a role of the PCC/RspC for the regulation of consciousness. We further submit that preserved corticocortical synchronization could represent a prerequisite for maintaining internal and external awareness. PMID:21330468

  8. Spontaneous default mode network phase-locking moderates performance perceptions under stereotype threat.

    Science.gov (United States)

    Forbes, Chad E; Leitner, Jordan B; Duran-Jordan, Kelly; Magerman, Adam B; Schmader, Toni; Allen, John J B

    2015-07-01

    This study assessed whether individual differences in self-oriented neural processing were associated with performance perceptions of minority students under stereotype threat. Resting electroencephalographic activity recorded in white and minority participants was used to predict later estimates of task errors and self-doubt on a presumed measure of intelligence. We assessed spontaneous phase-locking between dipole sources in left lateral parietal cortex (LPC), precuneus/posterior cingulate cortex (P/PCC), and medial prefrontal cortex (MPFC); three regions of the default mode network (DMN) that are integral for self-oriented processing. Results revealed that minorities with greater LPC-P/PCC phase-locking in the theta band reported more accurate error estimations. All individuals experienced less self-doubt to the extent they exhibited greater LPC-MPFC phase-locking in the alpha band but this effect was driven by minorities. Minorities also reported more self-doubt to the extent they overestimated errors. Findings reveal novel neural moderators of stereotype threat effects on subjective experience. Spontaneous synchronization between DMN regions may play a role in anticipatory coping mechanisms that buffer individuals from stereotype threat. PMID:25398433

  9. What we talk about when we talk about the default mode network

    Directory of Open Access Journals (Sweden)

    Felicity eCallard

    2014-08-01

    Full Text Available The default mode network (DMN has been widely defined as a set of brain regions that are engaged when people are in a ‘resting state’ (left to themselves in a scanner, with no explicit task instruction. The network emerged as a scientific object in the early twenty-first century, and in just over a decade has become the focus of intense empirical and conceptual neuroscientific inquiry. In this Perspective, we contribute to the work of critical neuroscience by providing brief reflections on the birth, working life, and future of the DMN. We consider: how the DMN emerged through the convergence of distinct lines of scientific investigation; controversies surrounding the definition, function and localization of the DMN; and the lines of interdisciplinary investigation that the DMN has helped to enable. We conclude by arguing that one of the most pressing issues in the field in 2014 is to understand how the mechanisms of thought are related to the function of brain dynamics. While the DMN has been central in allowing the field to reach this point, it is not inevitable that the DMN itself will remain at the heart of future investigations of this complex problem.

  10. Static and dynamic posterior cingulate cortex nodal topology of default mode network predicts attention task performance.

    Science.gov (United States)

    Lin, Pan; Yang, Yong; Jovicich, Jorge; De Pisapia, Nicola; Wang, Xiang; Zuo, Chun S; Levitt, James Jonathan

    2016-03-01

    Characterization of the default mode network (DMN) as a complex network of functionally interacting dynamic systems has received great interest for the study of DMN neural mechanisms. In particular, understanding the relationship of intrinsic resting-state DMN brain network with cognitive behaviors is an important issue in healthy cognition and mental disorders. However, it is still unclear how DMN functional connectivity links to cognitive behaviors during resting-state. In this study, we hypothesize that static and dynamic DMN nodal topology is associated with upcoming cognitive task performance. We used graph theory analysis in order to understand better the relationship between the DMN functional connectivity and cognitive behavior during resting-state and task performance. Nodal degree of the DMN was calculated as a metric of network topology. We found that the static and dynamic posterior cingulate cortex (PCC) nodal degree within the DMN was associated with task performance (Reaction Time). Our results show that the core node PCC nodal degree within the DMN was significantly correlated with reaction time, which suggests that the PCC plays a key role in supporting cognitive function. PMID:25904156

  11. Personality and complex brain networks: The role of openness to experience in default network efficiency.

    Science.gov (United States)

    Beaty, Roger E; Kaufman, Scott Barry; Benedek, Mathias; Jung, Rex E; Kenett, Yoed N; Jauk, Emanuel; Neubauer, Aljoscha C; Silvia, Paul J

    2016-02-01

    The brain's default network (DN) has been a topic of considerable empirical interest. In fMRI research, DN activity is associated with spontaneous and self-generated cognition, such as mind-wandering, episodic memory retrieval, future thinking, mental simulation, theory of mind reasoning, and creative cognition. Despite large literatures on developmental and disease-related influences on the DN, surprisingly little is known about the factors that impact normal variation in DN functioning. Using structural equation modeling and graph theoretical analysis of resting-state fMRI data, we provide evidence that Openness to Experience-a normally distributed personality trait reflecting a tendency to engage in imaginative, creative, and abstract cognitive processes-underlies efficiency of information processing within the DN. Across two studies, Openness predicted the global efficiency of a functional network comprised of DN nodes and corresponding edges. In Study 2, Openness remained a robust predictor-even after controlling for intelligence, age, gender, and other personality variables-explaining 18% of the variance in DN functioning. These findings point to a biological basis of Openness to Experience, and suggest that normally distributed personality traits affect the intrinsic architecture of large-scale brain systems. Hum Brain Mapp 37:773-779, 2016. © 2015 Wiley Periodicals, Inc. PMID:26610181

  12. Cortical morphometry in frontoparietal and default mode networks in math-gifted adolescents.

    Science.gov (United States)

    Navas-Sánchez, Francisco J; Carmona, Susana; Alemán-Gómez, Yasser; Sánchez-González, Javier; Guzmán-de-Villoria, Juan; Franco, Carolina; Robles, Olalla; Arango, Celso; Desco, Manuel

    2016-05-01

    Math-gifted subjects are characterized by above-age performance in intelligence tests, exceptional creativity, and high task commitment. Neuroimaging studies reveal enhanced functional brain organization and white matter microstructure in the frontoparietal executive network of math-gifted individuals. However, the cortical morphometry of these subjects remains largely unknown. The main goal of this study was to compare the cortical morphometry of math-gifted adolescents with that of an age- and IQ-matched control group. We used surface-based methods to perform a vertex-wise analysis of cortical thickness and surface area. Our results show that math-gifted adolescents present a thinner cortex and a larger surface area in key regions of the frontoparietal and default mode networks, which are involved in executive processing and creative thinking, respectively. The combination of reduced cortical thickness and larger surface area suggests above-age neural maturation of these networks in math-gifted individuals. Hum Brain Mapp 37:1893-1902, 2016. © 2016 Wiley Periodicals, Inc. PMID:26917433

  13. Escitalopram Decreases Cross-Regional Functional Connectivity within the Default-Mode Network.

    Directory of Open Access Journals (Sweden)

    Vincent van de Ven

    Full Text Available The default-mode network (DMN, which comprises medial frontal, temporal and parietal regions, is part of the brain's intrinsic organization. The serotonergic (5-HT neurotransmitter system projects to DMN regions from midbrain efferents, and manipulation of this system could thus reveal insights into the neurobiological mechanisms of DMN functioning. Here, we investigate intrinsic functional connectivity of the DMN as a function of activity of the serotonergic system, through the administration of the selective serotonin reuptake inhibitor (SSRI escitalopram. We quantified DMN functional connectivity using an approach based on dual-regression. Specifically, we decomposed group data of a subset of the functional time series using spatial independent component analysis, and projected the group spatial modes to the same and an independent resting state time series of individual participants. We found no effects of escitalopram on global functional connectivity of the DMN at the map-level; that is, escitalopram did not alter the global functional architecture of the DMN. However, we found that escitalopram decreased DMN regional pairwise connectivity, which included anterior and posterior cingulate cortex, hippocampal complex and lateral parietal regions. Further, regional DMN connectivity covaried with alertness ratings across participants. Our findings show that escitalopram altered intrinsic regional DMN connectivity, which suggests that the serotonergic system plays an important role in DMN connectivity and its contribution to cognition. Pharmacological challenge designs may be a useful addition to resting-state functional MRI to investigate intrinsic brain functional organization.

  14. Interactions between the salience and default-mode networks are disrupted in cocaine addiction.

    Science.gov (United States)

    Liang, Xia; He, Yong; Salmeron, Betty Jo; Gu, Hong; Stein, Elliot A; Yang, Yihong

    2015-05-27

    Cocaine dependence is a complex neuropsychiatric disorder manifested as dysregulation of multiple behavioral, emotional, and cognitive constructs. Neuroimaging studies have begun to identify specific neurobiological circuit impairments in cocaine-dependent (CD) individuals that may underlie these symptoms. However, whether, where, and how the interactions within and between these circuits are disrupted remain largely unknown. We used resting-state fMRI and modularity network analysis to identify brain modules of a priori interest (default-mode network [DMN], salience network [SN], executive control network [ECN], medial temporal lobe [MTL], and striatum) in 47 CD and 47 matched healthy control (HC) participants and explored alterations within and between these brain modules as a function of addiction. At the module level, intermodule connectivity decreased between DMN and SN in CD. At the nodal level, several regions showed decreased connections with multiple modules in CD: the rostral anterior cingulate connection strength was reduced with SN and MTL; the posterior cingulate had reduced connections with ECN; and the bilateral insula demonstrated decreased connections with DMN. Furthermore, alexithymia, a personality trait previously associated with addiction, correlated negatively with intramodule connectivity within SN only in cocaine users. Our results indicate that cocaine addiction is associated with disrupted interactions among DMN, MTL, and SN, which have been implicated, respectively, in self-referential functions, emotion and memory, and coordinating between internal and external stimuli, providing novel and important insights into the neurobiological mechanisms of cocaine addiction. PMID:26019326

  15. The psychedelic state induced by ayahuasca modulates the activity and connectivity of the default mode network.

    Directory of Open Access Journals (Sweden)

    Fernanda Palhano-Fontes

    Full Text Available The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs. A remarkable increase in introspection is at the core of these altered states of consciousness. Self-oriented mental activity has been consistently linked to the Default Mode Network (DMN, a set of brain regions more active during rest than during the execution of a goal-directed task. Here we used fMRI technique to inspect the DMN during the psychedelic state induced by Ayahuasca in ten experienced subjects. Ayahuasca is a potion traditionally used by Amazonian Amerindians composed by a mixture of compounds that increase monoaminergic transmission. In particular, we examined whether Ayahuasca changes the activity and connectivity of the DMN and the connection between the DMN and the task-positive network (TPN. Ayahuasca caused a significant decrease in activity through most parts of the DMN, including its most consistent hubs: the Posterior Cingulate Cortex (PCC/Precuneus and the medial Prefrontal Cortex (mPFC. Functional connectivity within the PCC/Precuneus decreased after Ayahuasca intake. No significant change was observed in the DMN-TPN orthogonality. Altogether, our results support the notion that the altered state of consciousness induced by Ayahuasca, like those induced by psilocybin (another serotonergic psychedelic, meditation and sleep, is linked to the modulation of the activity and the connectivity of the DMN.

  16. The psychedelic state induced by ayahuasca modulates the activity and connectivity of the default mode network.

    Science.gov (United States)

    Palhano-Fontes, Fernanda; Andrade, Katia C; Tofoli, Luis F; Santos, Antonio C; Crippa, Jose Alexandre S; Hallak, Jaime E C; Ribeiro, Sidarta; de Araujo, Draulio B

    2015-01-01

    The experiences induced by psychedelics share a wide variety of subjective features, related to the complex changes in perception and cognition induced by this class of drugs. A remarkable increase in introspection is at the core of these altered states of consciousness. Self-oriented mental activity has been consistently linked to the Default Mode Network (DMN), a set of brain regions more active during rest than during the execution of a goal-directed task. Here we used fMRI technique to inspect the DMN during the psychedelic state induced by Ayahuasca in ten experienced subjects. Ayahuasca is a potion traditionally used by Amazonian Amerindians composed by a mixture of compounds that increase monoaminergic transmission. In particular, we examined whether Ayahuasca changes the activity and connectivity of the DMN and the connection between the DMN and the task-positive network (TPN). Ayahuasca caused a significant decrease in activity through most parts of the DMN, including its most consistent hubs: the Posterior Cingulate Cortex (PCC)/Precuneus and the medial Prefrontal Cortex (mPFC). Functional connectivity within the PCC/Precuneus decreased after Ayahuasca intake. No significant change was observed in the DMN-TPN orthogonality. Altogether, our results support the notion that the altered state of consciousness induced by Ayahuasca, like those induced by psilocybin (another serotonergic psychedelic), meditation and sleep, is linked to the modulation of the activity and the connectivity of the DMN. PMID:25693169

  17. Functional Connectivity with the Default Mode Network Is Altered in Fibromyalgia Patients.

    Science.gov (United States)

    Fallon, Nicholas; Chiu, Yee; Nurmikko, Turo; Stancak, Andrej

    2016-01-01

    Fibromyalgia syndrome (FMS) patients show altered connectivity with the network maintaining ongoing resting brain activity, known as the default mode network (DMN). The connectivity patterns of DMN with the rest of the brain in FMS patients are poorly understood. This study employed seed-based functional connectivity analysis to investigate resting-state functional connectivity with DMN structures in FMS. Sixteen female FMS patients and 15 age-matched, healthy control subjects underwent T2-weighted resting-state MRI scanning and functional connectivity analyses using DMN network seed regions. FMS patients demonstrated alterations to connectivity between DMN structures and anterior midcingulate cortex, right parahippocampal gyrus, left superior parietal lobule and left inferior temporal gyrus. Correlation analysis showed that reduced functional connectivity between the DMN and the right parahippocampal gyrus was associated with longer duration of symptoms in FMS patients, whereas augmented connectivity between the anterior midcingulate and posterior cingulate cortices was associated with tenderness and depression scores. Our findings demonstrate alterations to functional connectivity between DMN regions and a variety of regions which are important for pain, cognitive and emotional processing in FMS patients, and which may contribute to the development or maintenance of chronic symptoms in FMS. PMID:27442504

  18. Metabolic mapping reveals sex-dependent involvement of default mode and salience network in alexithymia.

    Science.gov (United States)

    Colic, L; Demenescu, L R; Li, M; Kaufmann, J; Krause, A L; Metzger, C; Walter, M

    2016-02-01

    Alexithymia, a personality construct marked by difficulties in processing one's emotions, has been linked to the altered activity in the anterior cingulate cortex (ACC). Although longitudinal studies reported sex differences in alexithymia, what mediates them is not known. To investigate sex-specific associations of alexithymia and neuronal markers, we mapped metabolites in four brain regions involved differentially in emotion processing using a point-resolved spectroscopy MRS sequence in 3 Tesla. Both sexes showed negative correlations between alexithymia and N-acetylaspartate (NAA) in pregenual ACC (pgACC). Women showed a robust negative correlation of the joint measure of glutamate and glutamine (Glx) to NAA in posterior cingulate cortex (PCC), whereas men showed a weak positive association of Glx to NAA in dorsal ACC (dACC). Our results suggest that lowered neuronal integrity in pgACC, a region of the default mode network (DMN), might primarily account for the general difficulties in emotional processing in alexithymia. Association of alexithymia in women extends to another region in the DMN-PCC, while in men a region in the salience network (SN) was involved. These observations could be representative of sex specific regulation strategies that include diminished internal evaluation of feelings in women and cognitive emotion suppression in men. PMID:26341904

  19. Abnormal brain default-mode network functional connectivity in drug addicts.

    Directory of Open Access Journals (Sweden)

    Ning Ma

    Full Text Available BACKGROUND: The default mode network (DMN is a set of brain regions that exhibit synchronized low frequency oscillations at resting-state, and is believed to be relevant to attention and self-monitoring. As the anterior cingulate cortex and hippocampus are impaired in drug addiction and meanwhile are parts of the DMN, the present study examined addiction-related alteration of functional connectivity of the DMN. METHODOLOGY: Resting-state functional magnetic resonance imaging data of chronic heroin users (14 males, age: 30.1±5.3 years, range from 22 to 39 years and non-addicted controls (13 males, age: 29.8±7.2 years, range from 20 to 39 years were investigated with independent component analysis to address their functional connectivity of the DMN. PRINCIPAL FINDINGS: Compared with controls, heroin users showed increased functional connectivity in right hippocampus and decreased functional connectivity in right dorsal anterior cingulate cortex and left caudate in the DMN. CONCLUSIONS: These findings suggest drug addicts' abnormal functional organization of the DMN, and are discussed as addiction-related abnormally increased memory processing but diminished cognitive control related to attention and self-monitoring, which may underlie the hypersensitivity toward drug related cues but weakened strength of cognitive control in the state of addiction.

  20. Data for default network reduced functional connectivity in meditators, negatively correlated with meditation expertise.

    Science.gov (United States)

    Berkovich-Ohana, Aviva; Harel, Michal; Hahamy, Avital; Arieli, Amos; Malach, Rafael

    2016-09-01

    FMRI data described here was recorded during resting-state in Mindfulness Meditators (MM) and control participants (see "Task-induced activity and resting-state fluctuations undergo similar alterations in visual and DMN areas of long-term meditators" Berkovich-Ohana et al. (2016) [1] for details). MM participants were also scanned during meditation. Analyses focused on functional connectivity within and between the default mode network (DMN) and visual network (Vis). Here we show data demonstrating that: 1) Functional connectivity within the DMN and the Visual networks were higher in the control group than in the meditators; 2) Data show an increase for the functional connectivity between the DMN and the Visual networks in the meditators compared to controls; 3) Data demonstrate that functional connectivity both within and between networks reduces during meditation, compared to the resting-state; and 4) A significant negative correlation was found between DMN functional connectivity and meditation expertise. The reader is referred to Berkovich-Ohana et al. (2016) [1] for further interpretation and discussion. PMID:27508242

  1. Transfer of radionuclides in aquatic ecosystems - Default concentration ratios for aquatic biota in the Erica Tool

    International Nuclear Information System (INIS)

    The process of assessing risk to the environment following a given release of radioactivity requires the quantification of activity concentrations in environmental media and reference organisms. The methodology adopted by the ERICA Integrated Approach involves the application of concentration ratios (CR values) and distribution coefficients (Kd values) for aquatic systems. Within this paper the methodologies applied to derive default transfer parameters, collated within the ERICA Tool databases, are described to provide transparency and traceability in the documentation process. Detailed information is provided for the CR values used for marine and freshwater systems. Of the total 372 CR values derived for the marine ecosystem, 195 were identified by literature review. For the freshwater system, the number of values based on review was less, but still constituted 129 from a total of 372 values. In both types of aquatic systems, 70-80% of the data gaps have been filled by employing 'preferable' approaches such as those based on substituting values from taxonomically similar organisms or biogeochemically similar elements

  2. Establishing task- and modality-dependent dissociations between the semantic and default mode networks.

    Science.gov (United States)

    Humphreys, Gina F; Hoffman, Paul; Visser, Maya; Binney, Richard J; Lambon Ralph, Matthew A

    2015-06-23

    The default mode network (DMN) and semantic network (SN) are two of the most extensively studied systems, and both are increasingly used as clinical biomarkers in neurological studies. There are strong theoretical reasons to assume a relationship between the networks, as well as anatomical evidence that they might rely on overlapping cortical regions, such as the anterior temporal lobe (ATL) or angular gyrus (AG). Despite these strong motivations, the relationship between the two systems has received minimal attention. We directly compared the SN and DMN using a large (n = 69) distortion-corrected functional MRI (fMRI) dataset, spanning a range of semantic and nonsemantic tasks that varied input modality. The results showed that both networks fractionate depending on the semantic nature of the task, stimulus type, modality, and task difficulty. Furthermore, despite recent claims that both AG and ATL are semantic hubs, the two areas responded very differently, with results supporting the role of ATL, but not AG, in semantic representation. Specifically, the left ATL was positively activated for all semantic tasks, but deactivated during nonsemantic task performance. In contrast, the left AG was deactivated for all tasks, with the level of deactivation related to task difficulty. Thus, ATL and AG do not share a common interest in semantic tasks, but, rather, a common "disinterest" in nonsemantic tasks. The implications for the variability in the DMN, its cognitive coherence, and interpretation of resting-state fMRI data are discussed. PMID:26056304

  3. A multiscale method for a robust detection of the default mode network

    Science.gov (United States)

    Baquero, Katherine; Gómez, Francisco; Cifuentes, Christian; Guldenmund, Pieter; Demertzi, Athena; Vanhaudenhuyse, Audrey; Gosseries, Olivia; Tshibanda, Jean-Flory; Noirhomme, Quentin; Laureys, Steven; Soddu, Andrea; Romero, Eduardo

    2013-11-01

    The Default Mode Network (DMN) is a resting state network widely used for the analysis and diagnosis of mental disorders. It is normally detected in fMRI data, but for its detection in data corrupted by motion artefacts or low neuronal activity, the use of a robust analysis method is mandatory. In fMRI it has been shown that the signal-to-noise ratio (SNR) and the detection sensitivity of neuronal regions is increased with di erent smoothing kernels sizes. Here we propose to use a multiscale decomposition based of a linear scale-space representation for the detection of the DMN. Three main points are proposed in this methodology: rst, the use of fMRI data at di erent smoothing scale-spaces, second, detection of independent neuronal components of the DMN at each scale by using standard preprocessing methods and ICA decomposition at scale-level, and nally, a weighted contribution of each scale by the Goodness of Fit measurement. This method was applied to a group of control subjects and was compared with a standard preprocesing baseline. The detection of the DMN was improved at single subject level and at group level. Based on these results, we suggest to use this methodology to enhance the detection of the DMN in data perturbed with artefacts or applied to subjects with low neuronal activity. Furthermore, the multiscale method could be extended for the detection of other resting state neuronal networks.

  4. Self-processing and the default mode network: Interactions with the mirror neuron system

    Directory of Open Access Journals (Sweden)

    Istvan eMolnar-Szakacs

    2013-09-01

    Full Text Available Recent evidence for the fractionation of the default mode network (DMN into functionally distinguishable subdivisions with unique patterns of connectivity calls for a reconceptualization of the relationship between this network and self-referential processing. Advances in resting-state functional connectivity analyses are beginning to reveal increasingly complex patterns of organization within the key nodes of the DMN - medial prefrontal cortex (MPFC and posterior cingulate cortex (PCC – as well as between these nodes and other brain systems. Here we review recent examinations of the relationships between the DMN and various aspects of self-relevant and social-cognitive processing in light of emerging evidence for heterogeneity within this network. Drawing from a rapidly evolving social cognitive neuroscience literature, we propose that embodied simulation and mentalizing are processes which allow us to gain insight into another's physical and mental state by providing privileged access to our own physical and mental states. Embodiment implies that the same neural systems are engaged for self- and other-understanding through a simulation mechanism, while mentalizing refers to the use of high-level conceptual information to make inferences about the mental states of self and others. These mechanisms work together to provide a coherent representation of the self and by extension, of others. Nodes of the DMN selectively interact with brain systems for embodiment and mentalizing, including the mirror neuron system, to produce appropriate mappings in the service of social cognitive demands.

  5. The Brain on Art: Intense Aesthetic Experience Activates the Default Mode Network

    Directory of Open Access Journals (Sweden)

    Edward A Vessel

    2012-04-01

    Full Text Available Aesthetic responses to visual art comprise multiple types of experiences, from sensation and perception to emotion and self-reflection. Moreover, aesthetic experience is highly individual, with observers varying significantly in their responses to the same artwork. Combining fMRI and behavioral analysis of individual differences in aesthetic response, we identify two distinct patterns of neural activity exhibited by different subnetworks. Activity increased linearly with observers’ ratings (4-level scale in sensory (occipito-temporal regions. Activity in the striatum also varied linearly with ratings, with below-baseline activations for low-rated artworks. In contrast, a network of frontal regions showed a step-like increase only for the most moving artworks (4 ratings and non-differential activity for all others. This included several regions belonging to the default mode network previously associated with self-referential mentation. Our results suggest that aesthetic experience involves the integration of sensory and emotional reactions in a manner linked with their personal relevance.

  6. Changes in default mode network as automaticity develops in a categorization task.

    Science.gov (United States)

    Shamloo, Farzin; Helie, Sebastien

    2016-10-15

    The default mode network (DMN) is a set of brain regions in which blood oxygen level dependent signal is suppressed during attentional focus on the external environment. Because automatic task processing requires less attention, development of automaticity in a rule-based categorization task may result in less deactivation and altered functional connectivity of the DMN when compared to the initial learning stage. We tested this hypothesis by re-analyzing functional magnetic resonance imaging data of participants trained in rule-based categorization for over 10,000 trials (Helie et al., 2010) [12,13]. The results show that some DMN regions are deactivated in initial training but not after automaticity has developed. There is also a significant decrease in DMN deactivation after extensive practice. Seed-based functional connectivity analyses with the precuneus, medial prefrontal cortex (two important DMN regions) and Brodmann area 6 (an important region in automatic categorization) were also performed. The results show increased functional connectivity with both DMN and non-DMN regions after the development of automaticity, and a decrease in functional connectivity between the medial prefrontal cortex and ventromedial orbitofrontal cortex. Together, these results further support the hypothesis of a strategy shift in automatic categorization and bridge the cognitive and neuroscientific conceptions of automaticity in showing that the reduced need for cognitive resources in automatic processing is accompanied by a disinhibition of the DMN and stronger functional connectivity between DMN and task-related brain regions. PMID:27457134

  7. What can EMU countries' sovereign bond spreads tell us about market perceptions of default probabilities during the recent financial crisis?

    OpenAIRE

    Dötz, Niko; Fischer, Christoph

    2010-01-01

    This paper presents a new approach for analysing the recent development of EMU sovereign bond spreads. Based on a GARCH-in-mean model originally used in the exchange rate target zone literature, spreads are decomposed into a risk premium, an expected loss component and a liquidity premium. Time-varying default probabilities are derived. The results suggest that the rise in sovereign spreads during the recent financial crisis mainly reflects an increased expected loss component. In addition, t...

  8. Functional dissociation of ventral frontal and dorsomedial default mode network components during resting state and emotional autobiographical recall

    OpenAIRE

    Bado, Patricia; Engel, Annerose; de Oliveira-Souza, Ricardo; Bramati, Ivanei E.; Paiva, Fernando F; Basilio, Rodrigo; Sato, João R.; Tovar-Moll, Fernanda; Moll, Jorge

    2013-01-01

    Humans spend a substantial share of their lives mind-wandering. This spontaneous thinking activity usually comprises autobiographical recall, emotional, and self-referential components. While neuroimaging studies have demonstrated that a specific brain “default mode network” (DMN) is consistently engaged by the “resting state” of the mind, the relative contribution of key cognitive components to DMN activity is still poorly understood. Here we used fMRI to investigate whether activity in neur...

  9. Resting-State Glutamate and GABA Concentrations Predict Task-Induced Deactivation in the Default Mode Network

    OpenAIRE

    Hu, Yuzheng; Chen, Xi; Gu, Hong; Yang, Yihong

    2013-01-01

    Deactivation of the human brain's default mode network (DMN) is regarded as suppression of endogenous activity to support exogenous task-related processes. This phenomenon has important functional relevance and insufficient DMN deactivation has been implicated in several neuropsychiatric disorders. However, the neurochemical mechanism of the DMN′s deactivation remains largely unknown. In the present study, we test the hypothesis that the major excitatory and inhibitory neurotransmitters, glut...

  10. The chicken or the egg? A note on the dynamic interrelation between government bond spreads and credit default swaps

    OpenAIRE

    Delis, Manthos D; Mylonidis, Nikolaos

    2010-01-01

    This note provides the first empirical assessment of the dynamic interrelation between government bond spreads and their associated credit default swaps (CDS). We use data for the Southern European countries (Greece, Italy, Portugal and Spain) that found themselves with a problematic public sector in the dawn of the recent financial distress. We find that CDS prices Granger-cause government bond spreads after the eruption of the 2007 subprime crisis. Feedback causality is detected during peri...

  11. Credit derivatives: instruments of hedging and factors of instability. The example of ?Credit Default Swaps? on French reference entities

    OpenAIRE

    Rey, Nathalie

    2009-01-01

    Through a long-period analysis of the inter-temporal relations between the French markets for credit default swaps (CDS), shares and bonds between 2001 and 2008, this article shows how a financial innovation like CDS could heighten financial instability. After describing the operating principles of credit derivatives in general and CDS in particular, we construct two difference VAR models on the series: the share return rates, the variation in bond spreads and the variation in CDS spreads for...

  12. Optimal trade credit and order quantity when trade credit impacts on both demand rate and default risk

    OpenAIRE

    K-R Lou; W-C Wang

    2013-01-01

    In practice, to attract new buyers and to avoid lasting price competition, a seller frequently offers its buyers a permissible delay in payment (ie, trade credit). However, the policy of granting a permissible delay in payment adds an additional dimension of default risk to the seller. In contrast to previous researchers for finding optimal solutions to buyers, we first propose an economic order quantity model from the seller's prospective to determine its optimal trade credit and order quant...

  13. Slow EEG Pattern Predicts Reduced Intrinsic Functional Connectivity in the Default Mode Network: An Inter-Subject Analysis

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav; Alexakis, C.; Diukova, A.; Liddle, P.F.; Auer, D.P.

    2010-01-01

    Roč. 53, č. 1 (2010), s. 239-246. ISSN 1053-8119 Grant ostatní: European Commision Fp6(XE) MEST-CT-2005-021170 Institutional research plan: CEZ:AV0Z10300504 Keywords : fMRI * electroencephalography ( EEG ) * BOLD * resting state * low-frequency fluctuations * functional connectivity * default mode Subject RIV: FH - Neurology Impact factor: 5.932, year: 2010

  14. Relationship between the anterior forebrain mesocircuit and the default mode network in the structural bases of disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Nicholas D. Lant

    2016-01-01

    Full Text Available The specific neural bases of disorders of consciousness (DOC are still not well understood. Some studies have suggested that functional and structural impairments in the default mode network may play a role in explaining these disorders. In contrast, others have proposed that dysfunctions in the anterior forebrain mesocircuit involving striatum, globus pallidus, and thalamus may be the main underlying mechanism. Here, we provide the first report of structural integrity of fiber tracts connecting the nodes of the mesocircuit and the default mode network in 8 patients with DOC. We found evidence of significant damage to subcortico-cortical and cortico-cortical fibers, which were more severe in vegetative state patients and correlated with clinical severity as determined by Coma Recovery Scale—Revised (CRS-R scores. In contrast, fiber tracts interconnecting subcortical nodes were not significantly impaired. Lastly, we found significant damage in all fiber tracts connecting the precuneus with cortical and subcortical areas. Our results suggest a strong relationship between the default mode network – and most importantly the precuneus – and the anterior forebrain mesocircuit in the neural basis of the DOC.

  15. Whatever the customer wants, the customer gets? Exploring the gap between consumer preferences and default electricity products in Germany

    International Nuclear Information System (INIS)

    In liberalized electricity markets, residential customers can choose their preferred provider and select among a variety of different electricity products, including green power options. Successful product design and marketing strategies for green electricity may provide electricity providers with a competitive advantage, while at the same time contributing to energy policy objectives. This requires, however, a thorough understanding of customer preferences. We investigate the relative importance of different product attributes in creating customer value, and find that price and electricity mix are the two most important attributes. The German electricity customers we surveyed in 2009 expressed an implicit willingness to pay a premium of about 16% for electricity from renewable sources. We conclude that consumers are willing to pay a significant price premium for an upgrade from the current default electricity mix in Germany to a more environmentally friendly default electricity mix, and discuss implications for marketing strategy and energy policy. Our findings are based on a dataset of 4968 experimental choices made by 414 German residential consumers, collected in a stated preference survey. - Highlights: ► Study is based on 4968 experimental choices made by 414 German retail consumers. ► Apart from price, the electricity mix is the most important product attribute. ► Majority of consumers prefer nuclear-free electricity. ► Respondents are willing to pay a premium for green electricity. ► German default electricity mix does not correspond to current customer preferences.

  16. Changes in Default Alarm Settings and Standard In-Service are Insufficient to Improve Alarm Fatigue in an Intensive Care Unit: A Pilot Project

    OpenAIRE

    Sowan, Azizeh Khaled; Gomez, Tiffany Michelle; Tarriela, Albert Fajardo; Reed, Charles Calhoun; Paper, Bruce Michael

    2016-01-01

    Background Clinical alarm systems safety is a national concern, specifically in intensive care units (ICUs) where alarm rates are known to be the highest. Interventional projects that examined the effect of changing default alarm settings on overall alarm rate and on clinicians’ attitudes and practices toward clinical alarms and alarm fatigue are scarce. Objective To examine if (1) a change in default alarm settings of the cardiac monitors and (2) in-service nursing education on cardiac monit...

  17. Correlação de default: uma investigação empírica de créditos de varejo no Brasil

    OpenAIRE

    Antonio Carlos Magalhães da Silva; Arnildo da Silva Correa; Jaqueline Terra Moura Marins; Myrian Beatriz Eiras das Neves

    2010-01-01

    From data in the Central Bank of Brazil’s Credit Information System we empirically estimated the default correlation matrices of retail loans made between 2003 and 2008. The loan modalities studied were Consumer Credit and Vehicle Financing. We identified an increased probability and correlation of default during economic contraction in Brazil. The segmentation of correlation matrices was initially performed according to the risk rating of the transaction. However, based on a probit regressio...

  18. Le règlement des défauts sur le marché des credit default swaps : le cas de Lehman Brothers

    OpenAIRE

    Virginie Coudert; Mathieu Gex

    2010-01-01

    [eng] The Settlement of Lehman Brothers Bankruptcy on the Credit Default Swap Market Lehman Brothers bankruptcy created important risks for the credit default swap (CDS) market. Firstly, Lehman Brothers was a key participant of the CDS market, as buyer and seller of a large number of contracts. The counterparty risk, which had been neglected until then, suddenly became a major source of concern. The entanglement of positions on this OTC market has drastically increased the counterparty risk. ...

  19. Combination of DTI and fMRI reveals the white matter changes correlating with the decline of default-mode network activity in Alzheimer's disease

    Science.gov (United States)

    Wu, Xianjun; Di, Qian; Li, Yao; Zhao, Xiaojie

    2009-02-01

    Recently, evidences from fMRI studies have shown that there was decreased activity among the default-mode network in Alzheimer's disease (AD), and DTI researches also demonstrated that demyelinations exist in white matter of AD patients. Therefore, combining these two MRI methods may help to reveal the relationship between white matter damages and alterations of the resting state functional connectivity network. In the present study, we tried to address this issue by means of correlation analysis between DTI and resting state fMRI images. The default-mode networks of AD and normal control groups were compared to find the areas with significantly declined activity firstly. Then, the white matter regions whose fractional anisotropy (FA) value correlated with this decline were located through multiple regressions between the FA values and the BOLD response of the default networks. Among these correlating white matter regions, those whose FA values also declined were found by a group comparison between AD patients and healthy elderly control subjects. Our results showed that the areas with decreased activity among default-mode network included left posterior cingulated cortex (PCC), left medial temporal gyrus et al. And the damaged white matter areas correlated with the default-mode network alterations were located around left sub-gyral temporal lobe. These changes may relate to the decreased connectivity between PCC and medial temporal lobe (MTL), and thus correlate with the deficiency of default-mode network activity.

  20. Assigning Robust Default Values in Building Performance Simulation Software for Improved Decision-Making in the Initial Stages of Building Design

    Directory of Open Access Journals (Sweden)

    Kyosuke Hiyama

    2015-01-01

    Full Text Available Applying data mining techniques on a database of BIM models could provide valuable insights in key design patterns implicitly present in these BIM models. The architectural designer would then be able to use previous data from existing building projects as default values in building performance simulation software for the early phases of building design. The author has proposed the method to minimize the magnitude of the variation in these default values in subsequent design stages. This approach maintains the accuracy of the simulation results in the initial stages of building design. In this study, a more convincing argument is presented to demonstrate the significance of the new method. The variation in the ideal default values for different building design conditions is assessed first. Next, the influence of each condition on these variations is investigated. The space depth is found to have a large impact on the ideal default value of the window to wall ratio. In addition, the presence or absence of lighting control and natural ventilation has a significant influence on the ideal default value. These effects can be used to identify the types of building conditions that should be considered to determine the ideal default values.