Testing Goodness Of Fit Of The Geometric Distribution: An Application To Human Fecundability Data

A measure of reproduction in human fecundability studies is the number of menstrual cycles required to achieve pregnancy which is assumed to follow a geometric distribution with parameter p. Tests of heterogeneity in the fecundability data through goodness of fit tests of the geometric distribution are developed, along with a likelihood ratio test statistic and a score test statistic. Simulations show both are liberal, and empirical level of the likelihood ratio statistic is larger than that of the score test statistic. A power comparison shows that the likelihood ratio test has a power advantage. A bootstrap p-value procedure using the likelihood ratio statistic is proposed

Tests of exponentiality against some parametric over/under-dispersed life time models

We develop tests of goodness of fit of the exponential model against some over/under dispersion family of distributions. In particular, we develop 3 score test statistics and 3 likelihood ratio statistics. These are (S1, L1), (S2, L2), and (S3, L3) based on a general over-dispersed family of distributions, two specic over/under dispersed exponential models, namely, the gamma and the Weibull distributions, respectively. A simulation study shows that the statistics S3 and L3 have best overall performance, in terms of both, level and power. However, the statistic L3 can be liberal in some instances and it needs the maximum likelihood estimates of the parameters of the Weibull distribution as opposed to the statistic S3 which is very simple to use. So, our recommendation is to use the statistic S3 to test the fit of an exponential distribution over any over/under-dispersed exponential distribution

Interval Estimation of Some Epidemiological Measures of Association

In epidemiological cohort studies, the probability of developing a disease for individuals in a treatment/intervention group is compared with that of a control group. The groups involve varying cluster sizes, and the binary responses within each cluster cannot be assumed independently. Three major measures of association used to report the efficacy of treatments or effectiveness of public health intervention programs in case of prospective studies are Risk Difference (RD), Risk Ratio (RR) and Relative Risk Difference (RED). The preference of one measure of association over the other in drawing statistical inference depends on design of study. Lui (2004) discusses a number of methods of constructing confidence intervals for each of these measures. Specifically, Lui (2004) discusses four methods for RD, four methods for RR and three methods for RED. For the construction of confidence intervals for RD, Paul and Zaihra (2008) compare the four methods discussed by Lui (2004), using extensive simulations with a method based on an estimator of the variance of a ratio estimator by Cochran (1977) and a method based on a sandwich estimator of the variance of the regression estimator using the generalized estimating equations approach of Zeger and Liang (1986). Paul and Zaihra (2008) conclude that the method based on an estimate of the variance of a ratio estimator performs best overall. In this paper, we extend the two new methodologies introduced in Paul and Zaihra (2008) to confidence interval construction of the risk measures RR and RED. Extensive simulations show that the method based on an estimate of the variance of a ratio estimator performs best overall for constructing confidence interval for the other two risk measures RR and RED as well. This method involves a very simple variance expression which can be implemented with a very few computer codes. Therefore, it can be considered as an easily implementable alternative for all the three measures of association

Testing equality of scale parameters of two Weibull distributions in the presence of unequal shape parameters

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Introduction: Debates on the Measurement of Global Poverty

Global poverty is higher on the public agenda than ever before. While it has always been a central concern of development economists and professionals, it has never before been studied so intensively, and has never been as prominent in the public consciousness as it has become over the last few years. This new focus is due in part to the commitment of the international community to the United Nations Millennium Development Goals (MDGs)—the first of which is to halve, between 1990 and 2015, the proportion of people living in extreme poverty. It is due also to substantial progress in the collection and analysis of data. While we can now say much more about global poverty than in the past, considerable controversy has developed about how to analyze and interpret the data, and what they tell us about the magnitude and rate of change of global poverty

Who are the global top 1%?

This paper presents the first in-depth analysis of the changing composition of the global income rich and the rising representation of developing countries at the top of the global distribution. We construct global distributions of income between 1988 and 2012 based on both household surveys and the new top incomes data derived from tax records, which better capture the rich who are typically excluded from household surveys. We find that the representation of developing countries in the global top 1% declined until about 2002, but that since 2005 it has risen significantly. This coincides with a decline in global inequality since 2005, according to a range of measures. We compare our estimates of the country-composition and income levels of the global rich with a number of other sources – including Credit Suisse’s estimates of global wealth, the Forbes World Billionaires List, attendees of the World Economic Forum, and estimates of top executives’ salaries. To varying degrees, all show a rise in the representation of the developing world in the ranks of the global elite

Assessment of carrot growth performance with inoculation of AsT-PGPR under arsenic infested zone

In the present study, the maximum rhizobacterial population was observed in Nutrient Agar (NA) (average; Cfu=135×106) followed by King’s-B (average; Cfu=57×106), Soil extract agar (SEA) (average; Cfu=11×106), and Trypticase soy agar (TSA) (average; Cfu=9×106). Screening of arsenic tolerant rhizobacterial isolate revealed that about 1% of the bacterial isolate was from Nutrient Agar and King’s-B survived at 20ppb arsenic concentration, while 0.8% and 0.7% survived from TSA and SEA media respectively. 50ppb arsenic tolerant rhizobacteria were screened for plant growth-promoting activity such as IAA, Phosphate solubilization, Siderophore production, ACC deaminase activity. Maximum IAA activity was observed in rhizobacterial isolates, isolated from all different media. P- solubilizer, Siderophore producer, ACC deaminase, proline, and TSS activities were observed in the isolates of NA media followed by King’s-B media. 50ppb tolerate best suitable PGP traits producing isolates were inoculated to observe carrot plant growth in the pot experiment, Interesting and significant (p<0.05) result were observed in King’s-B media producer isolates; (Pseudomonas) induces plant length, chlorophyll-a and chlorophyll-b content of the plant after 60 days followed by 30 days

Pathological study of elective nephrectomies for a two year period

Background: Nephrectomies whether partial, total or radical are common surgical procedures these days with trauma being the most common cause of an emergency nephrectomy. The indications of elective nephrectomies vary with different age groups- malignancies being common in the elderly age group and non-neoplastic indications of nephrectomy may present in any age group. The present study was undertaken in view of the increasing elective nephrectomies in our area thus analyzing the common causes requiring nephrectomy as a treatment. The present study also aimed at determining the age and sex distribution of various renal lesions requiring a nephrectomy.Methods: It was a prospective study for a period of 2 years - January 2013 to December 2014. A total of 45 nephrectomies were included in the study. Detailed clinical, biochemical and imaging findings were taken into consideration before analyzing each case. Results: There was a male predominance(64.4%) and 26.6% of the cases were in the age group of 40-50 years. 95.5% of the nephrectomies were performed for a non-neoplastic indication. Involvement of the right and left kidney was almost equal in the study. Chronic pyelonephritis was the most common histopathological diagnosis(68.8%).Conclusion: Inflammatory causes more commonly required a nephrectomy in the study population.  Chronic calculous pyelonephritis was the most common underlying pathophysiology leading to a nonfunctioning kidney thus highlighting the early treatment of renal calculi.

Anti-Amyloid-β Single-Chain Antibody Brain Delivery Via AAV Reduces Amyloid Load But May Increase Cerebral Hemorrhages in an Alzheimer\u27s Disease Mouse Model

Accumulation of amyloid-β protein (Aβ) in the brain is thought to be a causal event in Alzheimer\u27s disease (AD). Immunotherapy targeting Aβ holds great promise for reducing Aβ in the brain. Here, we evaluated the efficacy and safety of anti-Aβ single-chain antibody (scFv59) delivery via recombinant adeno-associated virus (rAAV) on reducing Aβ deposits in an AD mouse model (TgAβPPswe/PS1dE9). First, delivery of scFv59 to the brain was optimized by injecting rAAV serotypes 1, 2, and 5 into the right lateral ventricle. Symmetrical high expression of scFv59 was found throughout the hippocampus and partly in the neocortex in both hemispheres via rAAV1 or rAAV5, while scFv59 expression via rAAV2 was mostly limited to one hemisphere. rAAV1, however, induced apoptosis and microglial activation but rAAV5 did not. Therefore, rAAV5 was selected for therapeutic scFv59 delivery in TgAβPPswe/PS1dE9 mice. rAAV5 was similarly injected into the ventricle of 10-month-old TgAβPPswe/PS1dE9 mice and 5 months later its efficacy and safety were evaluated. Immunoreactive Aβ deposits reduced in the hippocampus. Aβ42 levels in cerebrospinal fluid (CSF) tended to increase and the Aβ40 : 42 ratio decreased in CSF, suggesting that Aβ42 was relocated from the parenchyma to CSF. Hemorrhages associated with a focal increase in blood vessel amyloid were found in the brain. While immunotherapy has great potential for clearing cerebral Aβ, caution for cerebrovascular effects should be exercised when rAAV-mediated anti-Aβ immunotherapy is applied