Quantification of the natural history of visceral leishmaniasis and consequences for control

Background Visceral leishmaniasis has been targeted for elimination as a public health problem (less than 1 case per 10,000 people per year) in the Indian sub-continent by 2017. However, there is still a high degree of uncertainty about the natural history of the disease, in particular about the duration of asymptomatic infection and the proportion of asymptomatically infected individuals that develop clinical visceral leishmaniasis. Quantifying these aspects of the disease is key for guiding efforts to eliminate visceral leishmaniasis and maintaining elimination once it is reached. Methods Data from a detailed epidemiological study in Bangladesh in 2002–2004 was analysed to estimate key epidemiological parameters. The role of diagnostics in determining the probability and rate of progression to clinical disease was estimated by fitting Cox proportional hazards models. A multi-state Markov model of the natural history of visceral leishmaniasis was fitted to the data to estimate the asymptomatic infection period and the proportion of asymptomatic individuals going on to develop clinical symptoms. Results At the time of the study, individuals were taking several months to be diagnosed with visceral leishmaniasis, leading to many opportunities for ongoing transmission. The probability of progression to clinical disease was strongly associated with initial seropositivity and even more strongly with seroconversion, with most clinical symptoms developing within a year. The estimated average durations of asymptomatic infection and symptomatic infection for our model of the natural history are 147 days (95 % CI 130–166) and 140 days (95 % CI 123–160), respectively, and are significantly longer than previously reported estimates. We estimate from the data that 14.7 % (95 % CI 12.6-20.0 %) of asymptomatic individuals develop clinical symptoms—a greater proportion than previously estimated. Conclusions Extended periods of asymptomatic infection could be important for visceral leishmaniasis transmission, but this depends critically on the relative infectivity of asymptomatic and symptomatic individuals to sandflies. These estimates could be informed by similar analysis of other datasets. Our results highlight the importance of reducing times from onset of symptoms to diagnosis and treatment to reduce opportunities for transmission

Are CEOs to Blame for Corporate Failure? Evidence from Chapter 11 Filings

This study examines whether chief executive officers (CEOs) are to blame for corporate failures. Using alternative CEO managerial ability measures, we document that high-ability (low-ability) CEOs are less (more) likely to be associated with bankruptcy. We also find that reorganized firms run by high-ability incumbent CEOs experience improved financial performance after filing for Chapter 11. Firms that hire high-ability CEOs with bankruptcy experience also realize improved financial performance. Our evidence indicates that the likelihood of corporate bankruptcy is unrelated to the presence of high-ability managers and that bankruptcy does not adversely affect the post-bankruptcy careers of high-ability CEOs

Does Strategically Aligned Investment in Cybersecurity Systems Reduce Data Breach?

Background: Firms face increased data breach threats nowadays, creating a lack of consumer confidence. Increased data breach incidents are a major concern for every firm. However, in hospitals, it is paramount to safeguard medical records. A slight change in patient records can result in a life-threatening medical condition for a patient. Existing literature claims that cybersecurity investment has indeed increased the instances of data breach incidents. The adoption of Health Information Exchange (HIE) has exacerbated this risk by increasing multiple channels for potential hackers. We, therefore, analyze the relationship between cybersecurity investment and possible data breaches in the presence of moderating variables: adoption of HIE and entrepreneurial orientation to find a model to help minimize data breach incidents. Method: We test our hypotheses based on strategic alignment and resource orchestration theories. We merge two different datasets (HIMSS and the HHS website) to create a panel dataset with 24,587 observations on U.S. hospitals over five years (2013-2017). We then run a regression using SAS to analyze our model. Results: We find that cybersecurity investment has no significance in the data breach threats. However, when a hospital joins HIE, cybersecurity investment tends to reduce the data breach threats. We also find that hospitals with higher entrepreneurial orientation face reduced data breach threats when joining HIE. Conclusion: Hospitals should align their cybersecurity investment with their cybersecurity policies to generate maximum benefit from their cybersecurity investment. Failure to do so might result in a situation in which hospitals are always likely to face higher data security risks regardless of the level of cybersecurity investment

Characterizing the Interplay of Rubisco and Nitrogenase Enzymes in Anaerobic-Photoheterotrophically Grown \u3ci\u3eRhodopseudomonas palustris\u3c/i\u3e CGA009 through a Genome-Scale Metabolic and Expression Model

Rhodopseudomonas palustris CGA009 is a Gram-negative purple nonsulfur bacterium that grows phototrophically by fixing carbon dioxide and nitrogen or chemotrophically by fixing or catabolizing a wide array of substrates, including lignin breakdown products for its carbon and fixing nitrogen for its nitrogen requirements. It can grow aerobically or anaerobically and can use light, inorganic, and organic compounds for energy production. Due to its ability to convert different carbon sources into useful products during anaerobic growth, this study reconstructed a metabolic and expression (ME) model of R. palustris to investigate its anaerobic-photoheterotrophic growth. Unlike metabolic (M) models, ME models include transcription and translation reactions along with macromolecules synthesis and couple these reactions with growth rate. This unique feature of the ME model led to nonlinear growth curve predictions, which matched closely with experimental growth rate data. At the theoretical maximum growth rate, the ME model suggested a diminishing rate of carbon fixation and predicted malate dehydrogenase and glycerol-3 phosphate dehydrogenase as alternate electron sinks. Moreover, the ME model also identified ferredoxin as a key regulator in distributing electrons between major redox balancing pathways. Because ME models include the turnover rate for each metabolic reaction, it was used to successfully capture experimentally observed temperature regulation of different nitrogenases. Overall, these unique features of the ME model demonstrated the influence of nitrogenases and rubiscos on R. palustris growth and predicted a key regulator in distributing electrons between major redox balancing pathways, thus establishing a platform for in silico investigation of R. palustris metabolism from a multiomics perspective

Role of latent female genital tuberculosis in recurrent early pregnancy loss: A retrospective analysis

Background: Latent Female Genital tuberculosis (FGTB) or tubercular infestation is prevalent in Southeast Asia and even the presence of tubercular bacilli in the genital tract is becoming an important factor for reproductive failure. An immature endometrium becomes non-receptive, preventing implantation or rejection of implanted embryo in early months, resulting in recurrent pregnancy loss (RPL) in association with other factors. Objective: To detect the underlying causes of RPL in addition to the proven causes like uterine cavity defects, thrombophilia, chromosomal abnormalities, etc. Materials and Methods: 317 women with RPL, enrolled over a period of 60 months (January 2014 to December 2018) conducted at Calcutta Fertility Mission in the present study. They were grouped in A, B, and C and undergone routine tests for the same along with the PCR test with an endometrial aspirate. Results: Patients with only latent FGTB (Group A), patients with FGTB and associated factors (Group B), and patients with other causes of RPL (other than latent FGTB) (Group C) were34.4%, 42.3%, and 23.3% respectively. About 29.36%, 47.01%, and 21.62%of the patients had achieved pregnancy in Group A, B, and C, respectively. The rate of miscarriage was high in both Groups A and B, affected with latent FGTB, and live-birth was higher (75%) in Group C that did not have tubercular involvement of the genital tract. Conclusion: The tubercular infestation or latent FGTB as per our study appears to be a very important cause of RPL in patients with recurrent “unexplained” miscarriage. It should be treated adequately at an early stage to prevent permanent damage to pelvic organs and restore reproductive health in women. Key words: Female genital tuberculosis, Recurrent pregnancy loss, Endometrium, Implantation

Prevalence of hypertension and its risk factors among school teachers in Dhaka, Bangladesh

Background: School teachers in urban area are experiencing sedentary life style behaviors. This study was aimed to determine the prevalence and risk factors of hypertension (HTN) among school teachers in Dhaka city.Methods: This cross-sectional study was carried out from May to October of 2017. Total 323 school teachers in Dhaka city aged between 25-59 years were enrolled using cluster random sampling technique. Data on socio-demographic profile, different risk factors, co-morbidities, family history and blood pressure (BP) were recorded. HTN was recorded according to pre-defined criteria. Factors associated with HTN analyzed by Chi-square test (χ2).Results: The prevalence of HTN among school teachers was 52%. The mean ± SD age was 46.5±7.8 years. Majority teachers (52%) were earning between 20,000 and 50,000 Bangladeshi Taka per month and about 61.6% had service duration >15 years. Development of HTN was significantly associated with age, monthly family income and service duration (p=0.001). Majority participants were female (65.6%) and female to male ratio was 1.9:1. Female teachers were more hypertensive compared to male (68% vs 32%). Taking extra salt (OR 1.977, 95% CI 1.269-3.079), low intake of fresh vegetables (OR 2.048, 95% CI 1.228-3.416), higher waist circumference (OR 1.990, 95% CI 1.006-3.933) and mental distress (OR 1.724, 95% CI 1.045-2.844) were found to be significantly associated with HTN.Conclusions:The prevalence of HTN was higher among the study participants. Building awareness by promoting healthy life style and behaviors for prevention and control of HTN should be given importance among teachers. 

A global two-layer meta-model for response statistics in robust design optimization

Robust design optimization (RDO) of large-scale engineering systems is computationally intensive and requires significant CPU time. Considerable computational effort is still required within conventional meta-model assisted RDO frameworks. The primary objective of this article is to minimize further the computational requirements of meta-model assisted RDO by developing a global two-layered approximation based RDO technique. The meta-model in the inner layer approximates the response quantity and the meta-model in the outer layer approximates the response statistics computed from the response meta-model. This approach eliminates both model building and Monte Carlo simulation from the optimization cycle, and requires considerably fewer actual response evaluations than a single-layered approximation. To demonstrate the approach, two recently developed compressive sensing enabled globally refined Kriging models have been utilized. The proposed framework is applied to one test example and two real-life applications to illustrate clearly its potential to yield robust optimal solutions with minimal computational cost