Association of bioavailable estradiol levels and testosterone levels with serum albumin levels in elderly men

Estrogens are reported to be the essential sex steroid acting on some male physiological functions, and bioavailable estrogens comprise the free and albumin-bound fractions. Moreover, most of the bioavailable sex steroid is made up of albumin-bound fraction. We examined the age-related change in serum free, albumin-bound and bioavailable estradiol levels in comparison with each fraction of testosterone and its relationship with serum albumin level in elderly men. Albumin-bound as well as bioavailable estradiol levels declined with age, and their decreases were associated much more with the decrease of albumin level than the increase of sex-hormone binding globulin (SHBG) level in sixties and seventies, and similar results were recognized in the level of each fraction of testosterone, suggesting albumin levels have an important role for maintaining bioavailable sex steroid levels in males aged over sixty. Moreover, our study showed that SHBG levels associated inversely with bioavailable sex steroid levels particularly when serum albumin level was low. It seems likely that the decrease of bioavailable estradiol as well as testosterone is induced by the decrease of albumin-bound fractions in combination with the increase of SHBG-bound fractions in males aged over sixty, and that their physical characteristics of aging could be induced by the decrease of albumin-bound fractions caused by the decrease of serum albumin regardless of total sex steroid levels.     

Effects of neighborhood walkability on healthy weight: assessing selection and causal influences

Studies that examine the relationship between neighborhood characteristics and weight are limited because residents are not randomly distributed into neighborhoods. If associations are found between neighborhood characteristics and weight in observational studies, one cannot confidently draw conclusions about causality. We use data from the Utah Population Database (UPDB) that contain body mass index (BMI) information from all drivers holding a Utah driver license to undertake a cross-sectional analysis that compares the neighborhood determinants of BMI for youth and young adults. This analysis assumes that youth have little choice in their residential location while young adults have more choice. Our analysis makes use of data on 53,476 males and 47,069 females living in Salt Lake County in 2000. We find evidence of residential selection among both males and females when BMI is the outcome. The evidence is weaker when the outcomes are overweight or obesity. We conclude that studies that ignore the role of residential selection may be overstating the causal influence of neighborhood features in altering residents’ BMI.     

Impact factors of purse seine net and dip net fisheries on a chub mackerel population

There are two major kinds of fisheries for the chub mackerel in Japan. The purse seine net fishery exploits young and adult fish during the foraging season, while the dip net fishery exploits fish before and during the spawning season. To compare the damage to the chub mackerel stock caused by purse seine net and dip net fisheries, we introduced impact factors of the two kinds of fisheries on the two kinds of fisheries and estimated number of eggs spawned in 1982. We defined the impact factor as the ratio of the average reproductive value of individuals caught by each fishery to the reproductive value at maturity. The number of individuals caught by the purse seine net fishery was 66 times larger than the number caught by the dip net fishery, while the impact factor of the former was 84% of that of the latter. Thus, the total damage caused by the purse seine net fishery was much higher than the damage caused by the dip net fishery. We can evaluate the damage caused by mortality factors on endangered species using this method.     

Simultaneous estimation of mortality and dispersal rates of an artificially released population

Mark-recapture methods cannot estimate both mortality and dispersal rates of a wild population simultaneously. However, when an artificially cultured population is released into an area, the initial population size and the initial population distribution are usually known. If artificially cultured individuals are released with marks or distinguished from wild individuals or if no wild individual exists in the study area, we can estimate both the mortality and dispersal rates of the artificial population. The numbers of dispersed and dead individuals are estimated from the dispersal rate from the diffusion model and the total decreasing rate estimated from a mark-recapture data. We can estimate both the time-dependent and time-independent dispersal rates from the data. We choose the best fit model that has the smallest value of Akaike's Information Criteria. We also consider ‘concentric circles approximation” of spatial distribution, in which the cumulative and frequency distributions are analytically obtained.     

Model analysis of the effect of environmental fluctuation on the species replacement pattern of pelagic fishes under interspecific competition

Summary There are two factors affecting long-term fluctuation of planktotrophic pelagic fish: environmental fluctuation and interspecific competition. Long-term catch data of planktotrophic pelagic fishes in Japan suggest that the chub mackerel (species B) was replaced by the sardine (A), A was replaced by the anchovy, Pacific saury and horse mackerel (Group C), and species in group C were replaced by species B. If species A defeats B, B defeats C, and C defeats A in interspecific competitive ability, then the abundance of these three groups fluctuate forever and dominate in the same order. We call this cyclic advantage hypothesis for species replacement. In this model, environmental fluctuation affects the species replacement as a trigger. Environmental fluctuation does not determine the next dominant species but greatly affects when the next replacement occurs.     

A note on Whittaker–Henderson graduation: Bisymmetry of the smoother matrix

Abstract

Whittaker–Henderson (WH) graduation is a popular smoothing method that has been used for mortality table construction in the actuarial sciences and for the trend-cycle decomposition in time series econometrics. This paper proves that the smoother matrix of WH graduation is bisymmetric (i.e., symmetric centrosymmetric). This result implies, for example, that the first row of the smoother matrix is equivalent to the last row of it in reverse order. We also provide some related results.     

Culturally Based Intervention Development: The Case of Latino Families Dealing With Schizophrenia

OBJECTIVES: This article describes the process of developing a culturally based family intervention for Spanish-speaking Latino families with a relative diagnosed with schizophrenia. METHOD: Our iterative intervention development process was guided by a cultural exchange framework and based on findings from an ethnographic study. We piloted this multifamily group 16-session intervention with 59 Latino families in a randomized control trial. Data were collected on family- and client-level outcomes, and poststudy focus groups were conducted with intervention participants. RESULTS: Preliminary evidence indicates that the intervention is effective by increasing illness knowledge and reducing family burden. CONCLUSIONS: This work can provide a model for how to integrate cultural factors into psychosocial services and enhance interventions in real-world settings for culturally diverse populations.     

Asymptotic properties of the EPMC for modified linear discriminant analysis when sample size and dimension are both large

We deal with the problem of classifying a new observation vector into one of two known multivariate normal distributions when the dimension p and training sample size N   are both large with p<N$p<N$. Modified linear discriminant analysis (MLDA) was suggested by Xu et al. [10]. Error rate of MLDA is smaller than the one of LDA. However, if p and N   are moderately large, error rate of MLDA is close to the one of LDA. These results are conditional ones, so we should investigate whether they hold unconditionally. In this paper, we give two types of asymptotic approximations of expected probability of misclassification (EPMC) for MLDA as n→∞$n\to \infty$ with p=O(n^δ)$p=O(n^{\delta })$, 0<δ<1$0<\delta <1$. The one of two is the same as the asymptotic approximation of LDA, and the other is corrected version of the approximation. Simulation reveals that the modified version of approximation has good accuracy for the case in which p and N are moderately large.     

Search for Alternatives and Collaboration with Incumbents: Two-Sided Sourcing Behavior in Business Markets*

Sourcing strategies in business markets have been considered separately and the practice of two-sided sourcing behavior—engaging in search for alternative suppliers and collaboration with an incumbent supplier—has not been examined. To fill that gap, we first identify boundary conditions under which the poor performance of an incumbent supplier intensifies an original equipment manufacturer's (OEM) search and collaboration. Then, we examine how an OEM's two-sided sourcing behavior influences one of the critical elements of sourcing performance: the responsiveness of the incumbent supplier. Our proposed hypotheses were tested with data from a national survey of 539 OEM purchasing managers in the Japanese electronics industry. The analysis results indicate three main findings. First, two environmental conditions—pace of technological change and volume uncertainty—have contrasting influences on the link between incumbent supplier performance and an OEM's search and collaboration. While uncertainty from the upstream channel (pace of technological change) enhances an OEM's search and collaboration, uncertainty from the downstream channel (volume uncertainty) lowers an OEM's search and collaboration. Second, an OEM's dependence on its incumbent supplier has differential effects: an OEM reduces search as its dependence on incumbent supplier increases, while it enhances collaboration as its dependence on incumbent supplier increases. Third, while search alone has a negative effect on responsiveness of an incumbent supplier, engaging in two-sided sourcing behavior (i.e., combining search with collaboration) has a positive effect on responsiveness of the incumbent supplier.     

Estimating odds ratios through the connected comparative experiments

In Japan rarely repeated are the comparative clinical trials with the same pair of the test and control drugs. The simple approach fur a complete iaudomized block design regarding the trials as blocks cannot therefore be applied It; strengthening the evidence uf the difference between the two drugs. In tins paper a method is discussed lo KTOVCI minimal lull hum the ruliliei ted trials in which those two drugs are respectively compared with the common third drug. The method consists of testing homogeneity of trials, forming a combined est illicit oi uf the n odds latius if the homogeneity is yeiified aiid giving the asymptotic variance of the combined estimator.In particular an approach of the multiple comparisons is taken so as to give a homogeneous subset of trials when the overall homogeneity is not satisfied. Although the paper is motivated from the comparative clinical trials, the resulting method can be applied to general incomplete block experiments if the outcomes are binoinial variables and the nil-interaction hetn-ern thc trtatnlent and block is suspicious. On the other hand in the appplications to clinical trials the other. non mathenlatical conditions for a meta-analysis such as the coincidence of tllc protocol should be satisfied as discussed by Hedges and Olkin(1983).