Excessive Strand End Slip in Prestressed Piles

This paper presents the results of a research project that investigated excessive strand end slip observed recently in some prestressed piles. From measurements taken in the field, it is apparent that the problem o excessive initial strand slip is independent of pile shape and size. Strand end slip is evident in piles of different manufacturers in different states in the Southeast. Excessive strand end slip was found in both the top and bottom of the cross section of the piles, although the top portion of the cross section generally exhibited much higher initial slip. Several preventive measures can be adopted to reduce the excessive strand end slip. These preventive measures include: a) proper concrete mixture proportioning to reduce top bar effect; b) use of higher-strength concrete with the lowest possible slump and setting time; c) assessment of the condition of the strands prior to installation to insure excellent bond characteristics; d) gradual release of prestress, with an optimal release sequence; and e) use of adequate vibration to ensure consolidation. The strand end slip measured at five prestressing plants in the Southeast is considerably higher than the allowable end slip and is expected to affect the pile performance. If the strand slip theory is adopted, the strand development length increases substantially due to the excessive strand end slip. A top bar effect factor similar to the one used in reinforced concrete design is recommended. To maintain the excellent quality of precast and prestressed concrete products, manufacturers should adopt a dynamic quality control process that follows the rapid changes in the industry. More tests are necessary to ensure excellent quality, such as the Moustafa or an equivalent test, to assess the bond capabilities of the strands, end slip measurements, and direct measurement of the transfer length. Installation of piles should proceed in a manner to alleviate the top bar effects by placing piles alternately in their best and worst directions

A Small Conductance Calcium-Activated K⁺ Channel in C. elegans, KCNL-2, Plays a Role in the Regulation of the Rate of Egg-Laying

In the nervous system of mice, small conductance calcium-activated potassium (SK) channels function to regulate neuronal excitability through the generation of a component of the medium afterhyperpolarization that follows action potentials. In humans, irregular action potential firing frequency underlies diseases such as ataxia, epilepsy, schizophrenia and Parkinson's disease. Due to the complexity of studying protein function in the mammalian nervous system, we sought to characterize an SK channel homologue, KCNL-2, in C. elegans, a genetically tractable system in which the lineage of individual neurons was mapped from their early developmental stages. Sequence analysis of the KCNL-2 protein reveals that the six transmembrane domains, the potassium-selective pore and the calmodulin binding domain are highly conserved with the mammalian homologues. We used widefield and confocal fluorescent imaging to show that a fusion construct of KCNL-2 with GFP in transgenic lines is expressed in the nervous system of C. elegans. We also show that a KCNL-2 null strain, kcnl-2(tm1885), demonstrates a mild egg-laying defective phenotype, a phenotype that is rescued in a KCNL-2-dependent manner. Conversely, we show that transgenic lines that overexpress KCNL-2 demonstrate a hyperactive egg-laying phenotype. In this study, we show that the vulva of transgenic hermaphrodites is highly innervated by neuronal processes and by the VC4 and VC5 neurons that express GFP-tagged KCNL-2. We propose that KCNL-2 functions in the nervous system of C. elegans to regulate the rate of egg-laying. © 2013 Chotoo et al

Seasonal Distribution of Psychiatric Births in England

There is general consensus that season of birth influences the risk of developing psychiatric conditions later in life. We aimed to investigate whether the risk of schizophrenia (SC), bipolar affective disorder (BAD) and recurrent depressive disorder (RDD) is influenced by month of birth in England to a similar extent as other countries using the largest cohort of English patients collected to date (n=57,971). When cases were compared to the general English population (n=29,183,034) all diseases showed a seasonal distribution of births (SC p=2.48E-05; BAD p=0.019; RDD p=0.015). This data has implications for future strategies of disease prevention

Cationic polyelectrolytes: A new look at their possible roles as opsonins, as stimulators of respiratory burst in leukocytes, in bacteriolysis, and as modulators of immune-complex diseases (A review hypothesis)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44497/1/10753_2004_Article_BF00915991.pd

Refining behavioral dysregulation in borderline personality disorder using a sample of women with anorexia nervosa

One of the primary facets of borderline personality disorder (BPD) is behavioral dysregulation, a wide array of behaviors that are difficult to control and harmful to the individual. The purpose of this study was to explore the association between BPD and a variety of dysregulated behaviors, some of which have received little empirical attention. Using a large sample of individuals diagnosed with anorexia nervosa, 41 individuals diagnosed with BPD were compared to the rest of the sample on the presence of dysregulated behaviors using logistic regression analyses. Anorexia nervosa subtypes, age, and other Cluster B personality disorders were used as covariates. Results support an association between BPD and alcohol misuse, hitting someone/breaking things, provoking fights/arguments, self-injury, overdosing, street drug use, binge-eating, impulsive spending, shoplifting/stealing, and risky sexual behaviors. Differences between dichotomous and continuous measures of BPD yielded somewhat different results. Information on co-occurring anorexia nervosa and BPD was generated

Habitual starvation and provocative behaviors: Two potential routes to extreme suicidal behavior in anorexia nervosa

Anorexia nervosa (AN) is perhaps the most lethal mental disorder, in part due to starvation-related health problems, but especially because of high suicide rates. One potential reason for high suicide rates in AN may be that those affected face pain and provocation on many fronts, which may in turn reduce their fear of pain and thereby increase risk for death by suicide. The purpose of the following studies was to explore whether repetitive exposure to painful and destructive behaviors such as vomiting, laxative use, and non-suicidal self-injury (NSSI) was a mechanism that linked AN-binge-purging (ANBP) subtype, as opposed to AN-restricting subtype (ANR), to extreme suicidal behavior. Study 1 utilized a sample of 787 individuals diagnosed with one or the other subtype of AN, and structural equation modeling results supported provocative behaviors as a mechanism linking ANBP to suicidal behavior. A second, unexpected mechanism emerged linking ANR to suicidal behavior via restricting. Study 2, which used a sample of 249 AN patients, replicated these findings, including the second mechanism linking ANR to suicide attempts. Two potential routes to suicidal behavior in AN appear to have been identified: one route through repetitive experience with provocative behaviors for ANBP, and a second for exposure to pain through the starvation of restricting in ANR

Habitual starvation and provocative behaviors: Two potential routes to extreme suicidal behavior in anorexia nervosa. Behaviour Research and Therapy

a b s t r a c t Anorexia nervosa (AN) is perhaps the most lethal mental disorder, in part due to starvation-related health problems, but especially because of high suicide rates. One potential reason for high suicide rates in AN may be that those affected face pain and provocation on many fronts, which may in turn reduce their fear of pain and thereby increase risk for death by suicide. The purpose of the following studies was to explore whether repetitive exposure to painful and destructive behaviors such as vomiting, laxative use, and non-suicidal self-injury (NSSI) was a mechanism that linked AN-binge-purging (ANBP) subtype, as opposed to AN-restricting subtype (ANR), to extreme suicidal behavior. Study 1 utilized a sample of 787 individuals diagnosed with one or the other subtype of AN, and structural equation modeling results supported provocative behaviors as a mechanism linking ANBP to suicidal behavior. A second, unexpected mechanism emerged linking ANR to suicidal behavior via restricting. Study 2, which used a sample of 249 AN patients, replicated these findings, including the second mechanism linking ANR to suicide attempts. Two potential routes to suicidal behavior in AN appear to have been identified: one route through repetitive experience with provocative behaviors for ANBP, and a second for exposure to pain through the starvation of restricting in ANR