Estimation with stable disturbances

textThe family of stable distributions represents an important generalization of the Gaussian family; stable random variables obey a generalized central limit theorem where the assumption of finite variance is replaced with one of power law decay in the tails. Possessing heavy tails, asymmetry, and infinite variance, non-Gaussian stable distributions can be suitable for inference in settings featuring impulsive, possibly skewed noise. A general lack of analytical form for the densities and distributions of stable laws has prompted research into computational methods of estimation. This report introduces stable distributions through a discussion of their basic properties and definitions in chapter 1. Chapter 2 surveys applications, and chapter 3 discusses a number of procedures for inference, with particular attention to time series models in the ARMA setting. Further details and an application can be found in the appendices.Statistic

Evaluation of serum concentration of AFP marker in toxoplasmosis pregnant women with high level of IgG & IgM toxoplasma antibody by ELISA assay in a population of Tehran,Iran

Background and aims: Toxoplasmosis is a parasitic disease which may cause some laboratory symptoms in infected individuals. One of the main ways of transmition this organism is placenta to fetus pathway. If this transmission occurs in the 3th month of pregnancy, the abortion, central nerve system and ocular disorder will happen. Because of this issue, the precise technique for detection of Toxoplasma Antibody such as IgG and IgM is important, that contains ELISA to detect Toxoplasma Antibody such as IgG and IgM and AFP. Methods: This was a cross sectional study. In this study, the main sample was serum that was randomly collected from 255 pregnant women infected with toxoplasma Gondi in Avesina center. Then, It was detected the serum concentration of AFP in toxoplasmosis pregnant women with high level of IgG and IgM toxoplasma antibody by ELISA assay. Results: The results of this survey showed that the infection in these pregnant women by toxoplasma gondii was occurred and 13 of them (13 of 255 infected mothers) had high levels of AFP in their serum. The statistical analyses was done by SPSS consisted of t-test, case number, comparative study, and Q-Q plot evaluations. Conclusions: In some pregnant women with high level of IgG and IgM toxoplasma antibody was observed in high levels of AFP in their serum and this index correlates with NTD in their fetus

Expression of miR-302 in human embryo derived from in-vitro matured oocyte

Background: The expression of miR-302 over the period of early embryogenesis could possibly regulate the maternal transcript clearance. Zygotic transcription activation is mostly related to maternal messages degradation. Objective: In this study, the effects of in-vitro maturation technique (IVM) on the expression of miR-302 in human embryo produced from immature and mature human oocytes (matured in vitro and in vivo, before sperm exposure) obtained from females under gonadotrophin therapy were evaluated for assisted reproduction. Materials and Methods: Immature oocytes were cultured in vitro. The injection of oocytes-producing polar bodies was given using fresh sperm. Then, the embryo quality score was assessed in the IVM group compared with the control group. In both the groups, embryos with normal morphology were included in the molecular study. Only one blastomere was removed from three-day embryos and then the embryos were frozen. The expression of miR-302 in embryos was measured through quantitative realtime polymerase chain reaction. Results: Our data showed a significant reduction of miR-302 expression in the IVM group vs. the control group (p = 0.02). The embryo quality score showed a significant difference between the two groups (p = 0.01). Conclusion: The present study demonstrated that the IVM process had a negative effect on the expression level of miR-302 in human pre-implantation embryos. Considering the major role of expression miR-302, a reduced potential in miR-302 expression could be related to a decrease in the early embryonic development

Expression of Endothelial Nitric Oxide Synthase in Testicular Cells of Men with Obstructive Azoospermia; a Case-Control Study

Introduction: Obstructive azoospermia is one of the causes of post-testicular infertility in men and previous studies have reported inconsistent levels of endothelial nitric oxide synthase (eNOS) enzyme in these patients. Accordingly, the present study aimed to provide further evidence on the expression of eNOS enzyme in patients with azoospermia. Materials and Methods: In this case-control study, 10 patients, who were diagnosed with azoospermia and were referred to the infertility center for treatment or diagnosis, and 7 healthy fertile men were recruited. An informed written consent was obtained from included subjects and they underwent testicular biopsies. Samples were assessed via immunohistochemical methods to determine their levels of eNOS expression. Results: Both leydig and sertoli cells were found to express eNOS, while this enzyme was not expressed in normal germinal cells. The only significant difference between the two groups was the level of eNOS expression in sertoli cells which was found to be higher in patients with obstructive azoospermia compared to the control group (P<0.001). Conclusion: According to the results of this study, sertoli cells and their interactions with germinal cells of seminiferous tubule might play an important role in sperm quality and a subsequent successful fertilization

Optimal transportation and barycenter problems via convex functions

This work surveys developments in optimal transportation. The first three chapters develop background to optimal transportation problems and the associatedWasserstein distances in increasing levels of specificity. The first chapter introduces optimal transport problems and known properties characterizing optimal transport plans. The second chapter develops the Wasserstein distances, arising from specific cases of optimal transport problems. Properties for the 1 and 2-Wasserstein distances, the most well-understood cases, are presented and Wasserstein distances are characterized as integral probability metrics. The third chapter presents known optimal couplings for the quadratic Wasserstein distance. The rst section discusses optimal transport on R, which has been entirely characterized; the next two sections deal with known multivariate cases. The last three sections develop algorithmic and statistical applications of optimal transportation and Wasserstein distances. Chapter four surveys recent applications from the literature. New results are vi presented in chapters five and six. In chapter five, the problem of optimal transportation is approached by studying the convex functions underlying optimal transports, listing convex functions for known transports and introduce new cases. Chapter six develops barycentric applications. The rst section develops 2-Wasserstein barycenter results. Using a xed-point framework introduced in chapter four, immediate convergence and explicit representation of the barycenter is demonstrated for some classes of distributions. The next section develops applications of 2-Wasserstein barycenters to data modeling; barycenters are used to provide exible models interpolating between several input distributions. The final section develops an extended application of the WASP method introduced in chapter four. Finally we list useful results in appendices.Statistic

Male obesity is associated with sperm telomere shortening and aberrant mRNA expression of autophagy-related genes

Abstract Background Obesity is regarded a global public health crisis. It has been implicated in a variety of health problems, but when it comes to male fertility, how and to what extent obesity affects it are poorly understood. Accordingly, semen samples from 32 individuals with obesity (body mass index (BMI) ≥ 30 kg/m2) and 32 individuals with normal weight (BMI: 18.5-25 kg/m2) were obtained. Here, for the first time, we examined the association between obesity, relative sperm telomere length (STL) and autophagy-related mRNA levels such as Beclin1, AMPKa1, ULK1, BAX, and BCL2. Each group was also evaluated for conventional semen parameters, sperm apoptotic changes, DNA fragmentation index (DFI), sperm chromatin maturation, and reactive oxygen species (ROS) levels. Results Based on our findings, there was a marked reduction in relative STL in individuals with obesity as compared to the normal-weight group. We also found a significant negative correlation between relative STL and age, BMI, DFI, percentage of sperm with immature chromatin, and intracellular ROS levels in patients with obesity. In the normal-weight group, relative STL was only negatively correlated with DFI and intracellular ROS levels. Regarding mRNA expression, there was considerable upregulation of Beclin1, ULK1, and BCL2 in the group with obesity compared to the normal-weight group. Obesity was also found to be associated with a considerable decline in semen volume, total sperm count, progressive motility, and viability in comparison to normal-weight individuals. Furthermore, obesity was associated with considerably higher percentages of DFI, sperm with immature chromatin, late-stage apoptosis, and elevated ROS levels. Conclusion According to our findings, obesity is associated with sperm telomere shortening and aberrant autophagy-related mRNA expression. It should be emphasized that telomere shortening in sperm may be an indirect consequence of obesity due to the oxidative stress associated with the condition. Nevertheless, further investigation is required for a more comprehensive understanding

Aberrant Wnt/β-Catenin Signaling Pathway in Testis of Azoospermic Men​

Purpose: The Importance and key role of Wnt/β-catenin signaling pathway in spermatogenesis is known. Abnormalities of this pathway in Sertoli and germ cells leads to infertility. Leydig cells play an important role in spermatogenesis and male reproduction. As of now, exact position of the Wnt/β-catenin signaling pathway disorders in the tissue and possible involvement of Leydig cells has not been investigated. Methods: Samples of our previous study were used for common Y chromosome microdeletions screening and common CFTR gene mutations.1 β-catenin gene expression were evaluated and compared between testicular tissue obtained by testicular sperm extraction (TESE) in two groups of obstructive (n=10) and non-obstructive (n=10) azoospermic infertile men. Location of β-catenin accumulation was detected by immunofluorescence technic and quantitatively compared in the tissue followed by counterstaining with anti-vimentin antibody. It was used as specific marker of leydig cells to determine and confirm the cells in which this gathering was occurred. Results: β-catenin gene expression does not have a significant difference between the obstructive azoospermia (0.998) and non-obstructive azoospermia group (0.891). β-catenin was abnormally aggregated in leydig cell of non-obstructive azoospermic men. Conclusion: Gathering β-catenin in cytoplasm of leydig cells can disrupt spermatogenesis and cause infertility in men