Frailty modelling approaches for semi-competing risks data

Lifetime Data Analysis - In the semi-competing risks situation where only a terminal event censors a non-terminal event, observed event times can be correlated. Recently, frailty models with an...     

Impact of metabolic status on the association of serum vitamin D with hypogonadism and lower urinary tract symptoms/benign prostatic hyperplasia

Objective: The objective of this study is to investigate the impact of metabolic status on associations of serum vitamin D with hypogonadism and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH).

Patients and methods: A total of 612 men underwent physical examination, biochemical/hormonal blood testing, and transrectal prostate ultrasound. Moreover, the subjects filled out standard questionnaires for identification and grading of LUTS and hypogonadism symptoms. Parameters were statistically compared with independent t-tests and correlation analyses.

Results: Vitamin D levels positively correlated with total testosterone (TT) but not with prostate volume or International Prostate Symptom Score (IPSS). Patients with metabolic syndrome had significantly lower vitamin D levels, which were not correlated with TT, prostate volume, or IPSS. However, vitamin D was positively correlated with TT, and negatively correlated with prostate volume and quality-of-life IPSS in subjects without metabolic syndrome.

Conclusion: The clinical usefulness of vitamin D for treatment of hypogonadism or LUTS/BPH varies according to metabolic status.     

Do childbirth grants increase the fertility rate? Policy impacts in South Korea

In response to a low fertility rate, a number of municipalities in South Korea have been providing family benefits in the form of childbirth grants and child allowances. Using panel data for 230 municipalities that spans the years 2001–2014, this paper examines the impacts of family benefits on the fertility rate in Korea. I use the fact that different municipalities began providing the family benefits at different times to estimate the impact of family benefits on fertility rates using a difference-in-differences approach. This study finds a positive effect of family benefits on total fertility rate. Moreover, it finds little evidence of an anticipatory response within municipalities that adopted the policy. Given that a 10 million Korean won increase in family benefits is associated with a 3.5% increase in the total fertility rate, an increase in family benefits of about 44 million Korean won per child would be required to raise the total fertility rate to a safe zone above 1.5 children per woman, where population declines are gradual and easily reversed.     

Prosocial Motivation as a Driver of Social Innovation in the UAE

One important domain of nonmarket-driven innovation is social innovation. Defined as “new ideas that have the potential to improve either the quality or the quantity of life,” social innovation stands in stark contrast to business innovation that focuses on creativity with the intention of making a profit. Drawing on research on motivation, creativity, rentier mentality, and Islamic work ethics, this article takes a motivational approach to social innovation and advances a proposition that prosocial motivation is of particular importance in fostering social innovation in the context of the UAE. We argue that due to policies that grant nationals high financial stability and affluence, UAE locals are less likely to be driven by extrinsic motivation, but rather by intrinsic motivation. We propose that enhancing their prosocial motivation will have a synergetic effect with their intrinsic motivation and therefore lead to higher social innovation. This article extends the literature on prosocial motivation, social innovation, and social entrepreneurship by identifying a geographical/cultural region where the motivational basis for social innovation is amplified. Significantly, this article questions common assumptions about a rentier mentality and proposes a path to leverage social innovation. Implications for policymakers and practitioners are discussed.     

Electronic Play,Study, Communication,and Adolescent Achievement, 2003–2008

Adolescents’ time spent messaging, exploring websites, and studying on the computer increased between 2003 and 2008. Using data from the Panel Study of Income Dynamics Child Development Supplement, this study examines how such changes have influenced individual achievement and behavior from childhood to adolescence. Greater communications and Internet web time proved detrimental to vocabulary and reading whereas the increased use of computer games was associated with increased reading and problem‐solving scores, particularly for girls and minority children. Increased use of the computer for studying was associated with increased test scores for girls, but not boys. The consequences are more benign than many feared. Groups that have traditionally used the computer less (girls, minority children) appear to benefit from greater use.     

Resolute majority rules

We investigate resolute voting rules that always rank two alternatives strictly and avoid social indecision. Resolute majority rules differ from the standard majority rule in that whenever both alternatives win the same number of votes, a tie-breaking function is used to determine the outcome. We provide axiomatic characterizations of resolute majority rules or resolute majority rules with a quorum. Resoluteness axiom is used in all these results. The other axioms are weaker than those considered in the characterization of the majority rule by May (1952 Econometrica, 20:680–684). In particular, instead of May’s positive responsiveness, we consider a much weaker monotonicity axiom.     

Adolescent Sibling Relationship Quality and Adjustment: Sibling Trustworthiness and Modeling,as Factors Directly and Indirectly Influencing These Associations

The main goal of this study was to examine the direct and moderating effects of trustworthiness and modeling on adolescent siblings' adjustment. Data were collected from 438 families including a mother, a younger sibling in fifth, sixth, or seventh grade (M = 11.6 years), and an older sibling (M = 14.3 years). Respondents completed Web‐based surveys describing sibling conflict and warmth. Siblings reported on trustworthiness and modeling, and mothers described adjustment. Sibling conflict was directly associated with internalizing and externalizing behaviors for both siblings. The older siblings' reports of trustworthiness were directly associated with the outcome measures. The younger siblings' reports of trustworthiness were less directly associated, but a possible salutary effect was most evident under the highest levels of sibling conflict or warmth. Higher sibling modeling was a risk factor for adjustment problems in relations characterized by high conflict. Results support exploring trustworthiness as a key dimension of sibling relations.     

A high-quality-supplier selection model for supply chain management and ISO 9001 system

Supplier selection process for supply chain management (SCM) and ISO 9001 quality management system environments is considered. Determining suitable suppliers in the supply chain has become a key strategic consideration. However, the nature of these decisions is usually complex and unstructured. This paper proposes a high-quality-supplier selection (HQSS) model to deal with supplier selection problems in supply chain management. In selecting a supplier, quality management factors are considered first, and then price, delivery, etc. Quality management factors include a quality management audit, product testing, engineering work force, capability index, training time, etc., based on a five-interval scale. Next, the HQSS model determines the final solution by considering factors such as price, production lead-time, and delivery time.     

Internationalization and Performance of Firms in China: Moderating Effects of Governance Structure and the Degree of Centralized Control

This study proposes necessary modifications to the existing internationalization–performance relationship to meet the idiosyncrasies of China-specific contexts. We first hypothesize an S-shaped internationalization–performance relationship as the baseline and then investigate the moderating effects of a firm's governance structure and the degree of centralized government control on the relationship between its internationalization and performance. The results, based on a longitudinal sample of manufacturing firms in China for the 2001–2007 period, indicate that (1) the S-shaped internationalization–performance relationship holds for firms in China; (2) the governance structure moderates the internationalization–performance relationship such that increased profitability through internationalization is more likely for modernized firms than for their conventional local counterparts; and (3) the degree of centralized control moderates the internationalization–performance relationship such that increased profitability through internationalization is more likely for firms affiliated with higher level governments than for those affiliated with lower-level governments.