How a Navigation Channel Contributed to Most of the Flooding of New Orleans During Hurricane Katrina

Levee failures during Hurricane Katrina left 85% of New Orleans flooded, 1,500 dead, and about 400,000 homeless. Three separate investigations into the levee failures have been concluded, yet none of these studies conclusively determined why the St Bernard polder flooded so deeply, despite Team Louisiana’s conclusion regarding early failure of the Mississippi River Gulf Outlet (MRGO) levees. Detailed wave and hydrodynamic modeling reported here reveals the cause of extensive breaching of the MRGO levees and how that created a very efficient conduit of surge water into the heart of the city.     

Improving routing and scheduling decisions at a distributor of industrial gasses

This paper investigates cyclical inventory replenishment for a company's regional distribution center that supplies, distributes, and manages inventory of carbon dioxide (_CO2)$({\mathrm{CO}}_2)$ at over 900 separate customer sites in Indiana. The company previously experienced high labor costs with excessive overtime and maintained a regular back-log of customers experiencing stockouts. To address these issues we implemented a three-phase heuristic for the cyclical inventory routing problem encountered at one of the company's distribution centers. This heuristic determines regular routes for each of three available delivery vehicles over a 12-day delivery horizon while improving four primary performance measures: delivery labor cost, stockouts, delivery regularity, and driver–customer familiarity. It does so by first determining three sets of cities (one for each delivery vehicle) that must be delivered to each day based on customer requirements. Second, the heuristic assigns the remaining customers in other cities to one of the three “backbone routes” determined in phase 1. And third, it balances customer deliveries on each daily route over the schedule horizon. Through our methodology, we were able to significantly reduce overtime, driving time, and labor costs while improving customer service.     

Hans Georg Zilian, Unglück im Glück. Überleben in der Spaßgesellschaft

Ohne Zusammenfassung     

Investigating Family Shared Realities With Factor Mixture Modeling

The authors introduce factor mixture modeling (FMM) and its implications for assessing varying degrees of shared reality in families. FMM extends the typical factor analytic model that uses a set of observed indicators to identify an unobservable factor and its structure. FMM examines the possibility a sample is a mixture of “classes,” each with unique factor structures. To demonstrate, varying factor structures of father involvement are identified using father, mother, and child reports as observed indicators. Three classes were identified and relate to varying degrees of shared reality regarding the father. Predictors and outcomes of these classes are modeled. The class in which the child's view most overlapped with his or her parents' view was predicted by higher child agreeableness and higher levels of maternal depressive symptoms. As hypothesized, membership in this class predicted lower levels of parental conflict and fewer parental attempts to involve their children in their conflicts.     

American Indians’ Response to Physical Pain: Functional Limitations and Help-Seeking Behaviors

Seventy-five American Indians, ages 25 to 84, representing 14 tribal nations, participated in this study. The historical, cultural, and behavioral responses to physical pain were examined. Data were collected over a 7-month period with a survey instrument that included the Universal Pain Scale, activities of daily living, causes of pain, cultural beliefs, and self-help-seeking behaviors. Also, recommendations for Western biomedical health care professionals are offered to improve services for the American Indian population. Findings demonstrate that culture plays a crucial role in wellness and significantly affects help-seeking behaviors, treatment regimens, responses to pain, and pain management.     

Relationship between childbirth and access to postsecondary education among young women ageing out of foster care

Early childbirth is common among young women ageing out of foster care and may impede their educational progress. However, few studies have explored access to postsecondary education among young mothers who have been in foster care. The present study used data from a large, national sample of young people in foster care (National Youth in Transition Database, NYTD) to examine the link between early childbirth and young women's access to postsecondary education between ages 19 and 21, controlling for an array of covariates. The study sample included 2,207 young women who had completed a high school diploma or GED by age 19 and who participated in three NYTD interviews at ages 17, 19 and 21. Childbirth between ages 19 and 21 was linked to decreased access to postsecondary education. However, no relationship was found between access to postsecondary education and childbirth by age 17 or childbirth between ages 17 and 19. Implications for policy, practice and research are discussed.     

Bayesian modelling of effects of prenatal alcohol exposure on child cognition based on data from multiple cohorts

High levels of prenatal alcohol exposure (PAE) result in significant cognitive deficits in children, but the exact nature of the dose-response relationship is less well understood. To investigate this relationship, data were assembled from six longitudinal birth cohort studies examining the effects of PAE on cognitive outcomes from early school age through adolescence. Structural equation models (SEMs) are a natural approach to consider, because of the way they conceptualise multiple observed outcomes as relating to an underlying latent variable of interest, which can then be modelled as a function of exposure and other predictors of interest. However, conventional SEMs could not be fitted in this context because slightly different outcome measures were used in the six studies. In this paper we propose a multi-group Bayesian SEM that maps the unobserved cognition variable to a broad range of observed outcomes. The relation between these variables and PAE is then examined while controlling for potential confounders via propensity score adjustment. By examining different possible dose-response functions, the proposed framework is used to investigate whether there is a threshold PAE level that results in minimal cognitive deficit.