Experimental designs when there are one or more factor constraints

In response surface methodology, designs of orders one or two are often needed such that some or all the factor levels satisfy one or more linear constraints. A method is discussed for obtaining such designs by projection of a standard design onto the constraint hyperplane. It is shown that a projected design obtained from a rotatable design is also rotatable, and for a rotatable design that is also orthogonal (in particular any orthogonal first-order design) a least squares analysis carried out on the generating design supplies a least squares solution for the constrained design subject to the constraints. Some useful properties of the generating design, such as orthogonal blocking and fractionation are retained in the projected design. Some second-order mixture designs generated by two-level factorials are discussed.     

A New Proof of Murthy's Estimator which Applies to Sequential Sampling

Murthy's estimator has been used for constructing an unbiased estimator of a population total or mean from a sample of fixed size when there is unequal probability sampling without replacement. Traditionally, the estimator is derived by constructing an unordered version of Raj's ordered unbiased estimator. This paper presents an elementary proof of Murthy's estimator which applies the Rao–Blackwell theorem to a very simple estimator. This proof includes any sequential sampling scheme, thus extending the usefulness of Murthy's estimator. We demonstrate this extension by deriving unbiased estimators for inverse sampling.     

Choice Bracketing

When making many choices, a person can broadly bracket them by assessing the consequences of all of them taken together, or narrowly bracket them by making each choice in isolation. We integrate research conducted in a wide range of decision contexts which shows that choice bracketing is an important determinant of behavior. Because broad bracketing allows people to take into account all the consequences of their actions, it generally leads to choices that yield higher utility. The evidence that we review, however, shows that people often fail to bracket broadly when it would be feasible for them to do so. In addition to documenting the diverse effects of bracketing, we also discuss factors that determine whether people bracket narrowly or broadly. We conclude with a discussion of normative aspects of bracketing and argue that there are some situations in which narrower bracketing results in superior decision making.     

A New Understanding of Attention Deficit Hyperactivity Disorder: Alternate Concepts and Interventions

This paper explores alternate concepts for increasing our understanding of the intra/interpersonal difficulties that are observed in those with Attention Deficit Hyperactivity Disorder (ADHD). Language theory in correlation with under inhibition of responses, (not inattention, impulsivity, and hyperactivity), is explained, and demonstrates how those with ADHD are more vulnerable for developing intra/interpersonal struggles. Comorbidity as it presents with ADHD is examined as the resulting psychopathological symptomolgy possibly caused by untreated psychological, social and cognitive distress. This is in contrast to the prevailing idea that comorbid symptoms are always separate and distinct diagnoses. The psychoanalytic theories of object relations and affect attunement are defined and are linked to under inhibition of responses via dynamic intra/interpersonal processes and the presenting psychological, social and cognitive problems. Interventions are proposed that are behavioral and psychopharmacological, with a systems approach. Two cases are presented to illustrate how these treatment techniques translate into actual practice. All proposed interventions are aimed to address and anticipate the potential that individuals and families with ADHD experience under inhibition of responses with accompanying, maladaptive intra/interpersonal functioning.     

Effect of shoe type on descending a curb

The aim of this study was to evaluate the effect of shoe type on the performance of women during curb descent. Performance during curb stepping may be explained by biomechanical research that has evaluated the kinematics of overground walking and stair ascent and descent. Studies have reported that women exhibit performance differences when wearing high heels, flip flops and sneakers during overground walking and stair ascent and descent. Thus, in addition to features of the curb, the type of shoe being worn may also affect performance. Although several studies have investigated curb stepping, no known studies have investigated the effects of different types of footwear on curb descent performance. This research was conducted in a real-world environment where participants wore three different types of shoes and performed a series of activities that involved curb stepping. The subjects were videotaped while descending a curb, allowing for observation of changes in gait parameters. Results of this study indicate that wearing high heels leads to performance differences as compared to wearing flip flops or sneakers.     

Flexible empirical Bayes estimation for wavelets

Wavelet shrinkage estimation is an increasingly popular method for signal denoising and compression. Although Bayes estimators can provide excellent mean-squared error (MSE) properties, the selection of an effective prior is a difficult task. To address this problem, we propose empirical Bayes (EB) prior selection methods for various error distributions including the normal and the heavier-tailed Student t -distributions. Under such EB prior distributions, we obtain threshold shrinkage estimators based on model selection, and multiple-shrinkage estimators based on model averaging. These EB estimators are seen to be computationally competitive with standard classical thresholding methods, and to be robust to outliers in both the data and wavelet domains. Simulated and real examples are used to illustrate the flexibility and improved MSE performance of these methods in a wide variety of settings.     

On the existence and uniqueness of the NPMLE in biased sampling models

Identifiability, existence and uniqueness of the non-parametric maximum likelihood estimator (NPMLE) in biased sampling models are thoroughly investigated. The conditions for existence and uniqueness are considered from a different perspective and proofs are simplified. An extension to semi-parametric models is provided.     

A Clearer Picture of Multiracial Substance Use: Rates and Correlates of Alcohol and Tobacco Use in Multiracial Adolescents and Adults

Existing studies indicate that multiracial adolescents face greater substance use rates than monoracial adolescents. However, it is unclear whether the risk identified in adolescence persists into adulthood. The current study uses data from the 2001 California Health Interview Survey to analyze the alcohol and tobacco use of multiracial adolescents and adults compared to European American, African American, Native American, Asian/Pacific Islander American, and Latino American individuals. Results generally support the hypothesis that multiracial adolescents and adults face higher rates of substance use than African American and Asian/Pacific Islander American individuals, though this pattern of results was reversed in comparison with Native Americans and European Americans, and less consistent compared to Latino Americans. We further establish and discuss the correlates of drinking and smoking behavior for mixed-race individuals—comparing them to other racial groups. We review the limitations of our design and the implications for future research on multiracial substance use.     

Adaptive governance to promote ecosystem services in urban green spaces

Managing urban green space as part of an ongoing social-ecological transformation poses novel governance issues, particularly in post-industrial settings. Urban green spaces operate as small-scale nodes in larger networks of ecological reserves that provide and maintain key ecosystem services such as pollination, water retention and infiltration, and sustainable food production. In an urban mosaic, a myriad of social and ecological components factor into aggregating and managing land to maintain or increase the flow of ecosystem services associated with green spaces. Vacant lots (a form of urban green space) are being repurposed for multiple functions, such as habitat for biodiversity, including arthropods that provide pollination services to other green areas; to capture urban runoff that eases the burden on ageing wastewater systems and other civic infrastructure; and to reduce urban heat island effects. Because of the uncertainty and complexities of managing for ecosystem services in urban settings, we advocate for a governance approach that is adaptive and iterative in nature—adaptive governance—to address the ever changing social order underlying post-industrial cities and offer the rise of land banks as an example of governance innovation.     

Association of general and abdominal obesity with age,endocrine and metabolic factors in Asian men

Objective: This study made use of the percent abdominal fat to define abdominal obesity (AbO) and examined the differential associations of general obesity (GOb) and AbO with age, metabolic and endocrine factors.

Methods: Metabolic, endocrine and anthropometric factors and body composition were measured in 481 Asian men.

Results: A DEXA-derived ≥25% abdominal fat (PAbdF) was used to define men with AbO. Age was directly associated with PAbdF and percent total body fat (PBF). Exercise intensity was negatively associated with PBF. Both PBF and PAbdF were associated with HDL and LDL, but have opposite correlation with triglyceride. Furthermore, both PBF and PAbdF were associated with the number of metabolic syndrome (MetS) risk factors. Men with GOb had lower levels of percent lean mass (PLM), testosterone and bioavailable testosterone, and higher insulin and glucose levels. Men with AbO had lower arm and leg fat, higher insulin levels and triglycerides.

Conclusions: Men with GOb and AbO had different pattern of body composition. Age may be a contributory factor in AbO and a sedentary lifestyle may contribute to GOb. Both GOb and AbO are associated with an increased risk of MetS, with GOb more predispose to risk of diabetes, while AbO more at risk for cardiovascular diseases.