Combining poisson means

The problem of estimating the Poisson mean is considered based on the two samples in the presence of uncertain prior information (not in the form of distribution) that two independent random samples taken from two possibly identical Poisson populations. The parameter of interest is λ₁ from population I. Three estimators, i.e. the unrestricted estimator, restricted estimator and preliminary test estimator are proposed. Their asymptotic mean squared errors are derived and compared; parameter regions have been found for which restricted and preliminary test estimators are always asymptotically more efficient than the classical estimator. The relative dominance picture of the estimators is presented. Maximum and minimum asymptotic efficiencies of the estimators relative to the classical estimator are tabulated. A max-min rule for the size of the preliminary test is also discussed. A Monte Carlo study is presented to compare the performance of the estimator with that of Kale and Bancroft (1967).     

Traditional kinship foster care in northern Ghana: the experiences and views of children, carers and adults in Tamale

Surveys were employed to explore the experiences of children in care and their carers about traditional fostering. They also examined the perspectives of randomly selected adults in the community about the practice of traditional foster care in the Tamale area of northern Ghana. The 74 participants responded to closed- and open-ended interview questions about traditional foster care. Frequencies and thematic grouping of qualitative responses showed that the need to keep family ties alive was the key reason for placement of children with family and kin. Majority of the children expressed satisfaction with living in foster care, even though they had experienced physical and emotional abuse and intimidation. Although most carers were not formally employed and had little personal income, they were positive about having the care role, but faced challenges in providing for many children in a difficult economic situation. The report highlights the role of reciprocity, altruistic and socio-cultural factors in quality of care, and the potential for the traditional kinship foster care to provide suitable avenues of placement for children as recommended by the Ghana child rights law. It also identifies the need for education for carers around children's needs and Ghana's child rights law.     

Cervico‐motor reflex: Description of the reflex and role in sexual acts

A recently identified reflex, termed the “cervico‐motor reflex,” was studied in 15 healthy women (mean age 36.6 years). The response of levator ani (LA) and puborectalis (PR) muscles to electrical and mechanical stimulation of the cervix uteri (CU) was determined. One concentric needle electrode was inserted into the CU (stimulating), a second into the LA (recording), and a third into the PR (recording). The vaginal pressure was measured at rest and on cervical stimulation by balloon‐tipped catheters. Electrical stimulation of the CU led to a reduction in pressure in the upper portion of the vagina (p < .05) and an increase in pressure in the middle and lower portions (p < .001). Stimulation also caused an increase in the electromyographic (EMG) activity of the LA and PR muscles (p < .01). Mechanical stimulation induced the same effects but to a lesser degree. Stimulation of the anesthetized CU, LA, or PR did not evoke the response. The data suggested the presence of a reproducible reflex relationship between the CU and both the LA and PR. During the sexual act and penile buffeting of the CU, levator contraction “balloons” the upper vagina, which acts as a “receptacle” for the semen. Meanwhile, PR contraction narrows the lower vagina, which may effect an increase of penile erection and rigidity. The cervico‐motor reflex may be incorporated as an investigative tool in sexual act disorders.     

Pooling means under uncertain prior information with application to discrete distributions

The problem of pooling means is considered based on two samples in presence of the uncertain prior information that these samples are taken from possibly identical populations. Two discrete models, Poisson and binomial are considered in particular. Three estimators, i.e. the unrestricted estimator, shrinkage restricted estimator and estimators based on preliminary test are proposed. Their asymptotic mean squared errors are derived and compared. It is demonstrated via asymptotic results that the range of the parameter space in which shrinkage preliminary test estimator dominates the unrestricted estimator is wider than that of the usual preliminary test estimator. A Monte Carlo study for Poisson model is presented to compare the performance of the estimators for small samples.     

纪念苏丹商人穆罕默德·哈吉在华首设商务处

中国与阿拉伯非洲的历史交往源远流长,特别是与苏丹的联系,可以追溯到西汉时期,而且从那时起双方之间的往来一直延续不断。本文在历史回顾的基础上,通过实地调查和口传资料,着重考察了19世纪末苏丹商人穆罕默德·哈吉在广州首设商务办事处并开展苏(丹)中(国)贸易、加强双方社会联系的历史活动,揭示了苏中悠久关系史上鲜为人知的一页。     

Intrahousehold empowerment gaps in agriculture and children's well‐being in Bangladesh

This article examines the relationship between empowerment gaps between spouses and children's nutritional status and education using nationally representative data from the 2012 Bangladesh Integrated Household Survey. We measure relative empowerment of spouses using the recently developed Women's Empowerment in Agriculture Index. We find that while gender gaps in empowerment are only linked weakly to children's nutritional status, fathers’ and mothers’ empowerment have different effects on investment in children. Fathers’ empowerment is positively associated with younger children's nutrition and schooling, while mothers’ empowerment is more important for girls’ education in general and in keeping older boys and girls in school.     

Internalizing and externalizing problems and parenting: Results from a Saudi Arabian sample

Relatively few studies have attempted to identify factors that contribute to variation in parental behavior. The literature has revealed associations between both internal and external factors in the variation in parenting behaviors. In addition, the vast majority of the existing literature has focused almost exclusively on Western cultures (e.g., the USA). The current study addresses these limitations by examining direct and indirect pathways involving both internal and external sources of influence on parenting behaviors in a sample of adults from Saudi Arabia (N = 196). The employed statistical models revealed robust and consistent direct associations between the examined internalizing sources of influence (self-control and psychopathy) and parenting behaviors. Subsequent models revealed some evidence of mediation stemming from external sources of influence (namely, aggression). However, the resulting indirect effects were inconsistent, indicating that other, unmeasured mechanisms ultimately connect the examined internalizing problems and parenting behaviors.     

Optimal designs for asymmetrical factorial paired comparison experiments

Three forms of a general null hypothesis Ho on the factorial parameters of a general asymmetrical factorial paired comparison experiment are considered. A class of partially balanced designscorresponding to each form of H₀ is constructed and the A,D and ioptimal design, minimizing the trace, determinant and largest eigenvalue of a defined covariance matrix of related maximumlikelihoodestimators, in that class is determined. Moreover, the optimal design in each class maximizes the noncentrality parameter λ² of the asymptotic noncentral chi-square distribution of the likelihood ratiostatistic -2 log λ for testing H_o under defined local alternatives. These results apply directly to symmetrical factorial paired comparison experiments as special casesExamples are given forillustrating applications of the developed results     

RigiScan data under long-term testosterone therapy: improving long-term blood circulation of penile arteries,penile length and girth,erectile function,and nocturnal penile tumescence and duration

Background: Late-onset hypogonadism (LOH) presents with low serum testosterone (TT) levels and sexual and nonsexual symptoms. Erectile dysfunction affects a man’s self-esteem and as a result partner relationship and quality of life.

Objectives: To investigate the andrological clinical profile outcomes of testosterone therapy (TTh) in men (n?=?88) with symptomatic LOH complaints and symptoms.

Main outcome measures: Erectile function was assessed using the International Index of Erectile Function-5 questionnaire at baseline and at 6 and 12 months of TTh. In addition, penile length was measured at baseline and 12 months. We also evaluated nocturnal penile tumescence (NPT, using RigiScan) and blood flow of cavernous arteries (penile Doppler ultrasonography) at baseline and 12 months of TT.

Materials and methods: Eighty-eight LOH men (M_age 51.1 years) with erectile dysfunction, all with serum TT?<10.4?nmol/L before TTh. Patients received intramuscular long-acting testosterone undecanoate for 12 months.

Results: Following TTh, in all patients, serum TT levels were restored within 3 months to normal levels. Compared with baseline values, erectile function significantly improved at 6 (mean score increase 1.95) and 12 months (mean score increase 2.16). No significant changes in penile length were observed. NPT significantly improved at 12 months in terms of both the frequency (mean increase 1.27 times) and duration of rigidity (mean increase 5.12?min). As regards the blood flow of the cavernous arteries, we observed a significant improvement (decrease of 1.16?cm/s) and end diastolic velocity of the penile arteries.

Conclusion: TTh in men with LOH resulted in improvement of the erectile function, NPT, and to some extent the blood flow of the cavernous arteries.