A note on mixingale limit theorems and stable convergence in law

A gap in the proof of a non stationary mixingale invariance principle is identified and fixed by introducing a skipped subsampling of a partial sum process and letting the skipped interval vanish asymptotically at an appropriate rate as the sample size increases. The corrected proof produces a mixingale limit theorem in the form of a mixing convergence in law, occurring jointly with the stable convergence in law for the same σ-field relative to which they are stable and mixing. The applicability of established results to a high-frequency estimation of the quadratic variation of financial price process is discussed.     

Influence of a home-based exercise program on the urine pH in elderly female subjects: a secondary analysis of a randomized controlled trial

Background

A low urine pH is a characteristic metabolic feature of metabolic syndrome and type 2 diabetes. The purpose of the current study was to investigate the effects of a 12-week home-based bench step exercise on the urine pH status of elderly female subjects.

Methods

The current study is a secondary analysis of a randomized controlled trial (RCT) in which 59 postmenopausal female subjects were randomized to either the exercise group (n?=?29) or the control group (n?=?30). The subjects in the exercise group were instructed to perform home-based exercises using a bench step at the anaerobic threshold (AT), with a goal of performing ≥140 min/week at home for 12 weeks. The subjects in the control group were instructed to not change their normal lifestyle. Urine was collected after overnight fasting, and the urine pH was measured using a urinary test strip. The inter-group-differences at baseline and the pre-post changes within groups were assessed using the Mann-Whitney U test and Wilcoxon’s signed-rank test, respectively. Additionally, the difference in the post-intervention urine pH levels of the two groups, adjusted for the pre-intervention values (the estimated effect size) and the precision (95% confidence intervals) were investigated using an analysis of covariance.

Results

The pre-post comparison of the urine pH data using Wilcoxon’s signed-rank test showed a significant increase in the urine pH levels of the exercise group (p?<?0.05); there was no significant change in the urine pH levels of the control group. However, the estimated effect size (0.15) was small and the confidence interval straddled 0 (?0.25–0.55).

Conclusions

Based on the results of the current secondary analysis of an RCT, we could not clearly conclude that exercise has a beneficial effect on the urine pH. Further well-designed RCTs should be conducted to determine whether aerobic exercise is truly able to ameliorate urine acidification.

Trial registration

The study was retrospectively registered in the University Hospital Medical Information Network (UMIN) as “Effect of step exercise on aerobic fitness and progression of atherosclerosis in the elderly” under the registration number UMIN 000026743 (the date of registration: March 28, 2017).

     

Exposure Assessment of Heavy Metals Resulting from Farmland Application of Wastewater Sludge in Tianjin, China: The Examination of Two Existing National Standards for Soil and Farmland-Used Sludge

Land application is one of the major methods of managing municipal sludge in China. The sludge is used for fertilizing and conditioning soil, but due to the high concentration of heavy metals and other chemicals that it contains, improper use of sludge will lead to the contamination of farmland soil. To provide guidance on the application of sludge in China, the Control Standards for Pollutants in Sludge for Agricultural Use (CSPSAU) were enacted, and implemented in 1985. Afterwards, the National Environment Quality Standards for Soil (NEQSS) were also formulated and put into effect in 1996. In this article, these two national standards were examined by means of exposure assessment. The main exposure pathway to humans that was considered was dietary intake of crops grown on the sludge-applied farmland. Five major types of agricultural crops (rice, wheat, tuber roots, vegetables, and fruits) and three groups of exposure population (the urban individual group, the rural sludge-applying individual group, and the rural sludge nonapplying individual group) were assessed. This case study in Tianjin, China, shows the necessity of reexamining the national standards of the CSPSAU and the NEQSS in the context of risk assessment. More comprehensive surveys and monitoring programs assessing heavy metals contained in farmland soils and crop tissues will be necessary for examining the risks to human health.     

Social capital online: Collective use of the Internet and reciprocity as lubricants of democracy

This article puts the democratic potential of using the Internet into perspective through an analysis of how collective uses of the Internet promote social capital. Research results reveal that social capital online (i.e. trust and reciprocity) is enhanced by involvement in collective use of the Internet such as participation in online communities and use of the Internet among informal groups in everyday life. This process could counter negative aspects of Internet use. Further, accumulated online social capital can be a powerful predictor of online political participation, i.e. online reciprocity has a positive effect on intention to participate in online civic discussion. Finally, the authors' analyses indicate the possibility of a spillover of online social capital into offline arenas. It is concluded that collective use of the Internet can be a lubricant for democracy.     

Two-Step Residual-Based Estimation of Error Variances for Generalized Least Squares in Split-Plot Experiments

In split-plot experiments, estimation of unknown parameters by generalized least squares (GLS), as opposed to ordinary least squares (OLS), is required, owing to the existence of whole- and subplot errors. However, estimating the error variances is often necessary for GLS. Restricted maximum likelihood (REML) is an established method for estimating the error variances, and its benefits have been highlighted in many previous studies. This article proposes a new two-step residual-based approach for estimating error variances. Results of numerical simulations indicate that the proposed method performs sufficiently well to be considered as a suitable alternative to REML.     

人道主义竞争——历史的新潮流

放任自流的利已主义自由竞争，会陷入弱肉强食的自然淘汰主义。而以适当的结构及规矩为基础的竞争，将为人与社会带来活力，人道主义竞争的价值便在于此。这概念在认同竞争存在的必要性的同时，也确保竞争不与人道精神脱节。人道主义竞争所包含的活力，与人道主义所关注的课题牢牢地联系起来。这正是二十一世纪所需要的主流思想模式。     

Rules or No Rules? Three Strategies for Engagement with Young People in Mandated Services

A qualitative study of 61 youth receiving mandated services (child welfare, mental health, probation) or services where there were no alternatives (residential care for homeless youth) explored worker-client relationships from the perspective of young people themselves. Findings suggest three different but related roles played by workers that successfully engage adolescent clients: (1) “Informal supporters” de-professionalize their role and flatten hierarchies, emphasizing empathy and enforcing few rules; (2) “Administrators” enforce rules that are in the child’s best interest but do so with little emotional engagement; and (3) “Caregivers” who hold reasonable expectations and impose structures but are flexible in their negotiations with youth when rules were broken. While youth spoke most positively about their workers when they acted as informal supporters, a deeper analysis of the data showed that youth also engaged well with workers who enforced rules when those rules were necessary for the child’s safety, applied flexibly, age-appropriate, and fit with cultural norms. Use of all three approaches to youth engagement may help workers create better therapeutic relationships with youth receiving mandated services.     

Comparison of dispersal ability between the green leafhoppers,Nephotettix virescens andN. cincticeps (hemiptera: Cicadellidae) by tethered flight

Summary Dispersal propensity of green leafhoppers was compared between a tropical species,Nephotettix virescens, and a temperate species,N. cincticeps. The flight ability was measured with tethered flight technique under laboratory conditions (25°C, 16L-8D). The pre-flight period was shorter and the flight duration was longer inN. virescens than inN. cincticeps in both sexes. No significant correlations were found between the flight activity and morphometric characters for either of the two species. The results suggested that dispersal propensity ofN. virescens is higher than that ofN. cincticeps.