TTI hydraulics and erosion control laboratory research field performance of erosion-control blankets

Storm water management issues facing the Texas Department of Transportation in the late 1980s led to the development of a coordinated research program with the Texas Transportation Institute. Researchers developed methodologies for evaluating the field performance of various erosion control technologies of the most widely used products within the Department's construction and maintenance operations. From these methodologies, the Hydraulics and Erosion Control Laboratory was designed and constructed. Currently, participants include private industry (manufacturers of erosion control products), transportation researchers (TTI), and the public sector (TxDOT).The results reported in this paper reflect 2 years of erosion-control blanket research. The study objectives were to determine the effectiveness of erosion-control blankets on the growth of warm-season perennial grasses and their ability to prevent sediment loss in a sloped condition.The laboratory simulates the highway environment with the sloped plots (6 m in width) located on an earthen embankment that is 300 m in length and 6.75 m in height (94 ft. by 22 ft., vertically). A randomized experimental design was replicated on two soil types (sand and clay) for each slope condition (3:1 or 2:1) with a control.In general, the results indicate better combined results relating to sediment retention and vegetation establishment performance for erosion-control blankets on sandy soils (noncohesive) regardless of slope condition (3:1 or 2:1) or material type. A minimum of 50% more sediment was retained on the sandy treatment plots and a 45% more vegetation coverage was achieved compared with the control plots. When analyzed by material type related to performance, excelsior, synthetic blends, and straw/coconut blends performed the best. For clay soils (cohesive), regardless of slope condition (3:1 or 2:1), the combined results indicate a minimum of 75% more sediment was retained and a minimum of 5% more vegetation establishment was achieved compared with the control plots. When analyzed by material type related to performance, excelsior, straw, and straw/coconut blends performed the best.     

Women's Health Initiative: Why now? What is it? What's new?

Studies collectively named the Women's Health Initiative (WHI) are currently enrolling 164,500 postmenopausal women in several overlapping clinical trials and an observational study. The overall goals of WHI are to understand the determinants of postmenopausal women's health and to evaluate the efficacy of practical interventions in preventing the major causes of morbidity and mortality in older women. This article reviews the research leading to the WHI studies; describes the study designs and protocols, with an emphasis on what's new about WHI from a psychological perspective; and outlines the major psychosocial hypotheses under investigation and the major challenges WHI presents to psychological science. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mental health needs of physically disabled persons: Their perspective.

Evaluated disabled persons' perceptions of the types of problems experienced by the disabled population and the extent of this population's need for psychological services. 145 severely physically disabled former clients of a state rehabilitation commission responded to a questionnaire. Data show that 55% of Ss were aged 16–29 yrs, while 88% were 55 yrs old or less. 61.3% of Ss were males; 41% of Ss were married, 13% were divorced, 8% were separated, and 36% were single. 75% reported substantial need; 8% felt there was minimal or no need. Perceived problem areas included personal/emotional, organic/biological, marital/family, and vocational/career planning. Results suggest that this group of consumers perceives that there is a significant need for mental health services among individuals who are physically disabled. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental stability in jumping.

The principles of dynamical systems were used to study the effects of changing internal (i.e., developing subsystems) and external (i.e., task demands) constraints on the development of jumping. Children, 3, 5, 7, and 9 years old, and 3 groups of adults—of average skill, skilled in volleyball, and skilled in gymnastics—were filmed performing two different tasks, a standing long jump and a vertical jump. The results revealed that despite changes in both external and internal constraints, there were no differences in the pattern of coordination for jumping. Differences were found in the position and magnitude variables. Clearly, the constraints manipulated here were insufficient to disrupt the stability of the jump's coordination. We suggest that these results indicate that jumping is a stable movement organization that transcends the changes in constraints associated with developing subsystems and particular task demands. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In-home treatment of abusive families: Cost and placement at one year.

Evaluated a child-abuse prevention project designed to keep abused children safely at home. In-home prevention services were provided to 59 children in 26 families referred by county child protective services as an alternative to out-of-home placement. Therapists, carrying a caseload of 2 families each, provided intensive treatment in the families' homes for 4–6 wks. A comparison group of 24 child protective service referred families, with 49 children, received usual county services. A 1-yr follow-up evaluated the 2 groups on cost, on whether or not the children stayed at home, and on psychological measures of family functioning. Results indicate that the goals of reducing out-of-home placement and lowering placement costs were being met. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

29Si MAS NMR study of the hydration of tricalcium silicate in the presence of finely divided silica

²⁹Si magic angle spinning nuclear magnetic resonance spectroscopy has been used to investigate the effect of finely divided silica on the hydration of tricalcium silicate (C₃S). In order to reduce the time needed to obtain quantitative results, low levels of paramagnetic iron oxide were added to materials to increase the nuclear relaxation rate. The reactions of the C₃S and the finely divided silica could then be monitored separately and without chemical modification. The results were correlated with data from microcalorimetry, thermogravimetric analysis and electron microscopy. Under the conditions used here the presence of the silica accelerates greatly the hydration process, and results in a markedly increased degree of polymerization in the resulting gel, without significantly affecting the induction period of the reaction. The significance of these results for understanding the hydration process of C₃S in the presence of silica is outlined.     

Bidirectional Nerve Refractory Characteristics in Simulations of Direct and Remote Stimulation

The effects of remote stimulation on the refractory characteristics of myelinated nerve fibers were investigated using computer simulations of nerve action potentials, in response to spatially separated conditioning and test stimuli. The behavior of the test action potential was strongly influenced by its direction of propagation relative to that of the conditioning action potential. Under certain conditions, the variation of relative refractory period with conduction velocity (CV) changed from inverse, for propagation in opposing directions, to direct, for propagation in the same direction. A similar directionally dependent result occurred in the study of relative refractory period as a function of stimulus intensity. At certain interstimulus intervals, the test stimulus elicited action potentials which would conduct in the direction opposite to the conditioning action potential, but would not conduct in the wake of that conditioning action potential. These results are explained in terms of the spatial spread of stimulus current resulting from distant placement of the stimulating electrode in a volume conductor. Clinical repercussions of these results for correction of refractory period in collision neurography are discussed.     

Psychological predictors of good health in three longitudinal samples of educated midlife women.

Concurrent and longitudinal associations between cognitive and affective personality variables—intellectual efficiency (IE), anxiety, and hostility—and observer ratings of physical health were examined in 3 longitudinal samples of women: Mills Longitudinal Study (n?=?101); Radcliffe Study (RS, n?=?118); and University of California, San Francisco Study (n?=?44). Observer ratings of health were based on participants' reports of health problems. The California Psychological Inventory (H. G. Gough, 1996) IE, Hostility, and Anxiety Scales were used in all studies at Times 1 and 2, except in RS, when at Time 1 the Zung Anxiety (W. K. Zung, 1971) and the Profile of Mood States (D. M. McNair, M. Lorr, & L. F. Droppleman, 1971) Hostility Scales were used. In the majority of analyses, EE was positively associated with good health, and Anxiety and Hostility were negatively associated with health. IE was the strongest independent predictor of health, indicating that cognitive characteristics may have an important role in health and should be examined further. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning Binary Relations Using Weighted Majority Voting

In this paper we demonstrate how weighted majority voting with multiplicative weight updating can be applied to obtain robust algorithms for learning binary relations. We first present an algorithm that obtains a nearly optimal mistake bound but at the expense of using exponential computation to make each prediction. However, the time complexity of our algorithm is significantly reduced from that of previously known algorithms that have comparable mistake bounds. The second algorithm we present is a polynomial time algorithm with a non-optimal mistake bound. Again the mistake bound of our second algorithm is significantly better than previous bounds proven for polynomial time algorithms.A key contribution of our work is that we define a non-pure or noisy binary relation and then by exploiting the robustness of weighted majority voting with respect to noise, we show that both of our algorithms can learn non-pure relations. These provide the first algorithms that can learn non-pure binary relations.The first author was supported in part by NSF grant CCR-91110108 and NSF National Young Investigator Grant CCR-9357707 with matching funds provided by Xerox Corporation, Palo Alto Research Center and WUTA. The second author was supported by ONR grant NO0014-91-J-1162 and NSF grant IRI-9123692.     

A partitioning framework for Cassandra NoSQL database using Rendezvous hashing

Due to the gradual expansion in data volume used in social networks and cloud computing, the term “Big data” has appeared with its challenges to store the immense datasets. Many tools and algorithms appeared to handle the challenges of storing big data. NoSQL databases, such as Cassandra and MongoDB, are designed with a novel data management system that can handle and process huge volumes of data. Partitioning data in NoSQL databases is considered one of the critical challenges in database design. In this paper, a MapReduce Rendezvous Hashing-Based Virtual Hierarchies (MR-RHVH) framework is proposed for scalable partitioning of Cassandra NoSQL database. The MapReduce framework is used to implement MR-RHVH on Cassandra to enhance its performance in highly distributed environments. MR-RHVH distributes the nodes to rendezvous regions based on a proposed Adopted Virtual Hierarchies strategy. Each region is responsible for a set of nodes. In addition, a proposed bloom filter evaluator is used to ensure the accurate allocation of keys to nodes in each region. Moreover, a number of experiments were performed to evaluate the performance of MR-RHVH framework, using YCSB for database benchmarking. The results show high scalability rate and less time consuming for MR-RHVH framework over different recent systems.