Recent trends in modeling of deteriorating inventory

4. Modelling Survival Data in Medical Research

This paper presents a complete and up-to-date survey of published inventory literature for the deteriorating (decaying) inventory models. More specifically, those papers are addressed that consider the effect of deterioration as a function of the on-hand level of inventory. The basic features, extensions and generalization of various models are discussed. A classification scheme is presented along with suggestions for future research.

https://link.springer.com/content/pdf/10.1057%2Fjors.1991.4.pdf

Survey of Literature on Continuously Deteriorating Inventory Models

Infertility and problems of impaired fecundity have been a concern through ages and is also a significant clinical problem today, which affects 8-12% of couples worldwide. Of all infertility cases, approximately 40-50% is due to "male factor" infertility and as many as 2% of all men will exhibit suboptimal sperm parameters. It may be one or a combination of low sperm concentration, poor sperm motility, or abnormal morphology. The rates of infertility in less industrialized nations are markedly higher and infectious diseases are responsible for a greater proportion of infertility. The present literature will help in knowing the trends of male factor infertility in developing nations like India and to find out in future, various factors that may be responsible for male infertility.

Trends of male factor infertility, an important cause of infertility: A review of literature.

Approximately 10 to 15% of couples are impacted by infertility. Recently, the pivotal role that lifestyle factors play in the development of infertility has generated a considerable amount of interest. Lifestyle factors are the modifiable habits and ways of life that can greatly influence overall health and well-being, including fertility. Many lifestyle factors such as the age at which to start a family, nutrition, weight, exercise, psychological stress, environmental and occupational exposures, and others can have substantial effects on fertility; lifestyle factors such as cigarette smoking, illicit drug use, and alcohol and caffeine consumption can negatively influence fertility while others such as preventative care may be beneficial. The present literature review encompasses multiple lifestyle factors and places infertility in context for the couple by focusing on both males and females; it aims to identify the roles that lifestyle factors play in determining reproductive status. The growing interest and amount of research in this field have made it evident that lifestyle factors have a significant impact on fertility.

/pdf/lifestyle-factors-and-reproductive-health-taking-control-of-ob45s39pgz.pdf

Lifestyle factors and reproductive health: taking control of your fertility

In this paper we study the family of distributions termed as exponentiated Weibull distribution. The distribution has three parameters (one scale and two shape) and the Weibull distribution and the exponentiated exponential distribution, discussed by Gupta, et al. (1998), are particular cases of it. The survival function, failure rate and moments of the distributions have been derived using certain special formulas. The behavior of the failure rate has been studied and compared with those of the Weibull and Gamma distributions. The distribution has been fitted to a real life data set and the fit has been found to be very good.

/pdf/exponentiated-weibull-distribution-1amupybweu.pdf

Exponentiated Weibull distribution

This study was conducted as part of an epidemiological survey of 126 nonsmokers and 178 smokers, showing primary infertility residing around Kolkata region of Eastern India. Their lifestyle history including smoking habits along with semen and blood were collected. The study examined the association of cigarette smoking with the risk of infertility, by determining the semen quality, follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone levels, and androgen receptor (AR)-CAG repeat length in a group of smokers compared with a control group (non smokers). Based on conventional WHO criteria, lower sperm motility (P < 0.001) and increased sperm morphological defects (P < 0.0001) were associated with smoking habits. Binary logistic regression analysis for the effect of smoking status on sperm DNA integrity demonstrated significant positive correlation (p = 0.006). Serum FSH and LH levels were higher for smokers compared with non-smokers while the testosterone level decreased significantly ...

Effect of smoking on semen quality, FSH, testosterone level, and CAG repeat length in androgen receptor gene of infertile men in an Indian city

Reports indicate an increase in the incidence of DNA fragmentation in male factor infertility and its role in the outcome of assisted reproductive techniques (ART). However, reports are conflicting between the relationships of sperm DNA integrity with conventional semen parameters. We examined the relationship between conventional sperm parameters and DNA integrity using acridine orange (AO) test. The study included 373 patients and 28 fertile volunteers. DNA normality was compared with semen parameters between the patient and donor populations. Significant correlations were noted between DNA normality and sperm concentration (r = 0.18, P = 0.000), motility (r = 0.21, P = 0.0001), rapid motility (0.19, P = 0.000), normal morphology by World Health Organization (r = 0.15, P = 0.019) and head defects (r = -0.15, P = 0.023). A significant difference was noted in AO levels between donors and patients with asthenozoospermia (P = 0.002) and oligoasthenozoospermia (P = 0.001). A significant difference in DNA integrity was noted in samples having 30% normal morphology. A wide range of % DNA normality was observed in the patient group. Sperm assessment for DNA status using AO is reliable and shows good correlation with sperm count, motility and morphology. Assessment of sperm DNA status with AO staining may be helpful prior to ART.

/pdf/human-sperm-dna-integrity-in-normal-and-abnormal-semen-2b39lpbefa.pdf

Human sperm DNA integrity in normal and abnormal semen samples and its correlation with sperm characteristics

https://www.clevelandclinic.org/reproductiveresearchcenter/docs/agradoc305.pdf

Semen quality and age-specific changes: a study between two decades on 3,729 male partners of couples with normal sperm count and attending an andrology laboratory for infertility-related problems in an Indian city.

In this paper we study a number of new exponentiated distributions. The survival function, failure rate and moments of the distributions have been derived using certain special functions. The behavior of the failure rate has also been studied.

/pdf/some-exponentiated-distributions-4o9cz6qc2m.pdf

Manisha Pal

Papers

Exponentiated Weibull distribution

Effect of smoking on semen quality, FSH, testosterone level, and CAG repeat length in androgen receptor gene of infertile men in an Indian city

Human sperm DNA integrity in normal and abnormal semen samples and its correlation with sperm characteristics

Semen quality and age-specific changes: a study between two decades on 3,729 male partners of couples with normal sperm count and attending an andrology laboratory for infertility-related problems in an Indian city.

Some Exponentiated Distributions