Modified inference about the mean of the exponential distribution using moving extreme ranked set sampling

The maximum likelihood estimator (MLE) and the likelihood ratio test (LRT) will be considered for making inference about the scale parameter of the exponential distribution in case of moving extreme ranked set sampling (MERSS). The MLE and LRT can not be written in closed form. Therefore, a modification of the MLE using the technique suggested by Maharota and Nanda (Biometrika 61:601–606, 1974) will be considered and this modified estimator will be used to modify the LRT to get a test in closed form for testing a simple hypothesis against one sided alternatives. The same idea will be used to modify the most powerful test (MPT) for testing a simple hypothesis versus a simple hypothesis to get a test in closed form for testing a simple hypothesis against one sided alternatives. Then it appears that the modified estimator is a good competitor of the MLE and the modified tests are good competitors of the LRT using MERSS and simple random sampling (SRS).     

Adolescents' Physiological Reactions to Their Parents' Negative Disclosures About the Other Parent in Divorced and Nondivorced Families

The purpose of this study was to determine how adolescents in divorced and nondivorced families respond psychologically and physiologically to their parents' negative disclosures when talking about their parents' relationship. The study also investigated how parents respond to their own disclosures about their relationship with the other parent. In general, the results illustrate the important role that adolescents' feelings of being caught can contribute to their well-being. The findings also supported the hypothesis that the valence of parental disclosures was a more important consideration than its frequency in the understanding of adolescents' reactions to their parents' disclosures, especially for adolescents from divorced families. Disclosure valence was also associated with parental anxiety, such that disclosure negativity predicted elevations in parents' anxiety during the discussion. Ultimately, children from divorced families who already felt caught between their parents and whose parents tended to disclose negative information about the other parent to them were more likely than other adolescents to report feeling anxious during that conversation. The results for changes in physiological arousal were not significant and were not consistent with the results for self-reported anxiety.     

Decision to Emigrate amongst the Youth in Lebanon

This article studies the determinants of youth emigration decisions, which is considered one of the main causes of ‘Brain Drain’ in Arab Mediterranean Countries (AMCs). We focus on the case of Lebanon using a unique dataset covering young people aged 15 to 29 from the year 2016. The aim of the article is to identify the profile of youth's propensity to emigrate from Lebanon. The empirical results indicate that youth from non‐wealthy backgrounds living in smaller dwellings have a higher propensity to emigrate. It is also found that being male and unemployed has a positive effect on migration. Moreover, university education promotes the willingness to emigrate; while residents of poor regions are more likely to express such willingness. Finally, the article provides some insights for policymakers.     

Does China receive more regional FDI than gravity would suggest?

It is an empirical regularity that the activities of multinational corporations are concentrated in their home region. This has been shown to be the case for a majority of the 500 largest multinationals as well as for subsets of this 500 sorted by region or industry. The analysis has also been applied to the activities of a sample of all US and OECD multinationals, aggregated by country. These concentrations have been explained using theories, such as region-bound FSAs which constrain the ability of multinationals to internationalize, as well as transactions costs which make doing business outside a multinational’s home market more costly. To date, there has been no analysis that focuses on the regional and global character of multinational activity destined for China. This paper works to fill that void. Using data on FDI into China from each investor country over the period 1995–2005, this paper documents a significant regional concentration of Asian multinational activity operating within China. This regional concentration is sustained even after the special relationships with Hong Kong and (other) Offshore Financial Centres are accounted for. The evidence therefore extends the evidence of regional concentrations of MNE activities found elsewhere to China and its relationship with Asia.     

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.     

On the most imbalanced orientation of a graph

We study the problem of orienting the edges of a graph such that the minimum over all the vertices of the absolute difference between the outdegree and the indegree of a vertex is maximized. We call this minimum the imbalance of the orientation, i.e. the higher it gets, the more imbalanced the orientation is. The studied problem is denoted by \({{\mathrm{\textsc {MaxIm}}}}\). We first characterize graphs for which the optimal objective value of \({{\mathrm{\textsc {MaxIm}}}}\) is zero. Next we show that \({{\mathrm{\textsc {MaxIm}}}}\) is generally NP-hard and cannot be approximated within a ratio of \(\frac{1}{2}+\varepsilon \) for any constant \(\varepsilon >0\) in polynomial time unless \(\texttt {P}=\texttt {NP}\) even if the minimum degree of the graph \(\delta \) equals 2. Then we describe a polynomial-time approximation algorithm whose ratio is almost equal to \(\frac{1}{2}\). An exact polynomial-time algorithm is also derived for cacti. Finally, two mixed integer linear programming formulations are presented. Several valid inequalities are exhibited with the related separation algorithms. The performance of the strengthened formulations is assessed through several numerical experiments.     

Some Aspects of Communicable and Non-communicable Diseases in Pacific Island Countries

This study provides an overview of the incidence of the communicable and non-communicable diseases in Pacific Island countries. Available health statistics confirms that children continue to die annually due to neonatal causes, diarrhoeal diseases, pneumonia and measles. The adult population in several countries reveals presence and emergence of communicable and non-communicable diseases. Among the communicable diseases is the prevalence of HIV/AIDS among the 15–49 years old age group, it is considered to be less than 0.1% in several countries but in Papua New Guinea (PNG), it is about 0.3%. Marshall Islands, Tuvalu, Kiribati, PNG and Solomon Islands reveal high prevalence of tuberculosis while PNG, Solomon Islands and Vanuatu are the three Malaria prone countries. In terms of non-communicable diseases, cardiovascular disease is the leading cause of mortality in several countries with Nauru recording highest incidence followed by Tuvalu, Marshall Islands and Fiji. People in several countries are in the pre-hypertension category with a high risk of developing hypertension. Several countries have serious obesity problems and in the Cook Islands, Micronesia, Nauru, Niue, Palau, Samoa and Tonga; more than 60% of population is obese, and in all countries females are more obese than males. Diabetes is prevalent in all countries and Nauru has the highest percentage of prevalence of diabetes while in Fiji, Kiribati, Marshall Islands and Micronesia, approximately 8% of people aged 20 and above suffers from diabetes. Fiji, Nauru, PNG, Samoa, Tonga and Vanuatu reveal high incidences of cigarette smokers while the consumption of alcohol is high in Niue and in the Cook Islands.     

An Adventure in Publishing: Eighteen Years of the Applied Probability Trust1

This paper describes the foundation of the Applied Probability Trust and the launching of the Journal of Applied Probability in 1964. The Trust office was set up in Sheffield in 1965; the Trust has since published Mathematical Spectrum (1968) and Advances in Applied Probability (1969). Various other publishing ventures are described, and some statistics given for the Applied Probability journals. In conclusion, tentative plans for the future of the Trust are outlined.