Modeling considerations in seismic assessment of RC bridges using state-of-practice structural analysis software tools

The increasing awareness of the general society toward the seismic safety of structures has led to more restrictive performance requirements hence, many times, to the need of using new and more accurate methods of analysis of structures. Among these, nonlinear static procedures are becoming, evermore, the preferred choice of the majority of design codes, as an alternative to complete nonlinear time-history analysis for seismic design and assessment of structures. The many available software tools should therefore be evaluated and well understood, in order to be easily and soundly employed by the practitioners. The study presented herein intends to contribute to this need by providing further insight with respect to the use of commonly employed structural analysis software tools in nonlinear analysis of bridge structures. A comparison between different nonlinear modeling assumptions is presented, together with the comparison with real experimental results. Furthermore, alternative adaptive pushover procedures are proposed and applied to a case study bridge, based on a generic plastic hinge model. The adopted structural analysis program proved to be accurate, yielding reliable estimates, both in terms of local plastic hinge behavior and global structural behavior.     

Fatigue crack in large-scale tubular joints for offshore structures

Tubular members have been used for constructing offshore structures. Large-scale fatigue tests of welded tubular K-joints under the balanced in-plane bending brace were carried out to investigate the fatigue behavior of API 2W Gr.50 steel produced by POSCO. The experimental results were verified by numerical approaches and compared with the IIW, DnV RP-C203 and API RP 2A-WSD design curves. The test results based on the hot spot stress were in agreement with the design curves. The SCF factor for tubular K-jo...     

Shelf-life of Sterile Yellow-eyed Mullet (Aldrichetta forsteri) at 4°C

The relative effects of microbial and nonmicrobial spoilage on the shelf-life of yellow-eyed mullet were studied. Results of sensory and chemical analyses of sterile flesh stored at 4°C were compared with fillets which had either spoiled naturally while held at 4°C or frozen fillets held at ?18°C. Inosine was produced rapidly in both treatments at 4°C, followed in sterile flesh by a slower breakdown to hypoxan-thine. Hypoxanthine production from inosine was rapid in the presence of bacteria. Within 6 days sensory changes were observed in the frozen flesh and after 69 days, it was considered unacceptable. The development of off-odors and off-flavors in the absence of bacteria was not sufficiently slow to result in a significant extension in shelf-life for this species.     

Quantifying psychological victimization: scientific uncertainty, legal necessity

Quantifying psychological victimization presents a formidable conundrum for psychiatry and the law. On the one hand, the task is fundamentally uncertain, due to causal complexity that includes disparity between projected image and inner reality, context dependence, volition, and conflicting interests. On the other hand, the task is necessary for just determination in such areas of law as disability assessment, victim impact, compensation, and psychological crimes such as harassment. A multiaxial protocol is proposed to meet this problematic charge. The five dimensions of this protocol are (1) gross estimate of victimization, including severity of the stressor, the degree of resulting impairment, and variably, the degree of the victim's nonresponsibility; (2) reliability; (3) other conditions; (4) conflicts of interest; and (5) evaluator bias. Intuitive estimates are used widely here instead of operationalized criteria, to enhance flexibility and widen relevance. Evaluators are asked to determine and explain the weighting that should be given to different factors and to give a self-statement of their own biases.     

RasGRP, a Ras guanyl nucleotide- releasing protein with calcium- and diacylglycerol-binding motifs

RasGRP, a guanyl nucleotide-releasing protein for the small guanosine triphosphatase Ras, was characterized. Besides the catalytic domain, RasGRP has an atypical pair of "EF hands" that bind calcium and a diacylglycerol (DAG)-binding domain. RasGRP activated Ras and caused transformation in fibroblasts. A DAG analog caused sustained activation of Ras-Erk signaling and changes in cell morphology. Signaling was associated with partitioning of RasGRP protein into the membrane fraction. Sustained ligand-induced signaling and membrane partitioning were absent when the DAG-binding domain was deleted. RasGRP is expressed in the nervous system, where it may couple changes in DAG and possibly calcium concentrations to Ras activation.     

Dietary risk factors for pre-eclampsia among women attending Harare Maternity Hospital, Zimbabwe

OBJECTIVE: To identify specific foods that predispose Zimbabwean women to a higher or lower risk of pre-eclampsia and/or eclampsia. DESIGN: A case control study was implemented. Participants were asked by questionnaire to recall the specific amounts of meats, poultry, fruits, fish, vegetables and dairy products they had consumed in the month prior to giving birth. SETTING: Harare Maternity Hospital, Harare, Zimbabwe between June of 1995 and April of 1996. SUBJECTS: 180 women clinically diagnosed with pre-eclampsia (144) or eclampsia (36), and 194 normotensive women without these conditions. MAIN OUTCOME MEASURES: Pre-eclampsia/eclampsia. RESULTS: There were few associations between consumption of specific food items and the occurrence of pre-eclampsia/eclampsia. Meat and fruit were the only foods found to be significantly associated with pre-eclampsia. Women who consumed 12 or more servings of meat per month were more likely to have pre-eclampsia/eclampsia when compared to women eating 11 servings of meat or less per month. While intake of bananas and mangos was unrelated to risk, women who consumed other fruits (i.e. apples, oranges, grapes, peaches, apricots, paw paw, and plums), were 1.7 (95% CI = 1.0 to 3.1) times more likely to develop pre-eclampsia/eclampsia as women who ate none of these fruits. However, women who consumed relatively large quantities of these fruits were not at a particularly high risk. Increased consumption of kapenta was modestly associated with a decrease in disease risk, but this finding was well within the limits of chance and no association was present with intake of other types of fish. CONCLUSIONS: Our findings suggest that variation in consumption of specific foods do not have a strong effect on the incidence of pre-eclampsia in this population. However, further research involving the use of a more comprehensive dietary measure, biochemical measurements of nutrients, pre-pregnancy assessment and ascertainment of dietary intake prior to the development of pre-eclampsia are needed.     

First recorded outbreak of yellow fever in Kenya, 1992-1993. II. Entomologic investigations

OBJECTIVES: The physiology of the female sexual response and its molecular mediators remain poorly understood. Nitric oxide (NO) is synthesized in neurons and is a potent relaxor of vascular and nonvascular smooth muscle. In this study, we hypothesize that vaginal atrophy and declining sexual function during menopause may be NO dependent. Using the rat as an experimental model, we examined the expression and topologic localization of vaginal NO synthase (NOS) and the concomitant induction of apoptosis under normal and estrogen-depleted conditions. METHODS: Thirty rats were categorized into six groups on the basis of phase of the estrous cycle or estrogen status after oophorectomy. The expression and cellular localization of NOS was examined in frozen sections using specific antibodies against neuronal (N-NOS) and endothelial NOS (E-NOS). Apoptotic cells were identified in situ using the terminal transferase technique (TUNEL). Trichome staining was performed in all specimens to determine smooth muscle/collagen ratios. RESULTS: N-NOS immunoreactivity was localized to nerve fibers supplying vaginal smooth muscle, perivascular nerve plexuses, and lamina propria. E-NOS was localized to vascular endothelium and perivascular smooth muscle fibers. Both E-NOS and N-NOS expression in intact cycling animals was highest during proestrous and lowest during metestrous. After oophorectomy, levels of both N-NOS and E-NOS declined substantially compared with those of intact animals, and there was a parallel induction of apoptosis. Estrogen withdrawal also resulted in increased vaginal atrophy, intramural collagen accumulation, and perivascular wall thickening, as identified by trichome staining. Estrogen replacement resulted in a significant increase in E-NOS and N-NOS expression, as well as diminished apoptosis and vaginal atrophy. CONCLUSIONS: This cellular distribution of NOS in the rat vagina suggests that NO may modulate both vaginal blood supply and vaginal smooth musculature. Estrogen appears to play a critical role in concomitantly regulating vaginal NOS expression and apoptosis in nerves, smooth muscle, vascular endothelium, and epithelium of the rat vagina. These findings may have significant clinical implications for the pathophysiology of postmenopausal female sexual dysfunction.     

Structure-function analysis of the herpes simplex virus type 1 UL12 gene: correlation of deoxyribonuclease activity in vitro with replication function

Although the product of the UL12 gene of herpes simplex virus type 1 (HSV-1) has been shown to possess both exonuclease and endonuclease activities in vitro, and deletion of most of the gene within the viral genome results in inefficient production and maturation of infectious virions, the function of the deoxyribonuclease (DNase) activity per se in virus replication remains unclear. In order to correlate the in vitro and in vivo activities of the protein encoded by UL12, mutant proteins were tested for nuclease activity in vitro by a novel hypersensitivity cleavage assay and for their ability to complement the replication of a DNase null mutant, AN-1. Rabbit reticulocyte lysates programmed with wild-type UL12 RNA cleaved at the same sites cleaved by purified HSV-1 DNase, but distinct from those cleaved by DNase 1 or micrococcal nuclease. All mutants which lacked DNase activity in vitro also failed to complement the replication of AN-1 in nonpermissive cells. Likewise, all mutants which contained HSV-1 DNase activity, as detected by the hypersensitivity cleavage assay, were capable of complementing the replication of the DNase null mutant, though to varying extents. Of particular note was the d1-126 mutant protein, which, despite having the same specific activity as the wild-type enzyme in vitro, complemented the replication of AN-1 significantly less than the wild-type protein. The results suggest that DNase activity per se is required for efficient replication of HSV-1 in vivo. However, residues, including the N-terminal 126 amino acids, which are dispensable for enzymatic activity in vitro may facilitate the accessibility or activity of the protein in vivo.