Bauschinger effect in Nb and V alloyed line-pipe steels

The UOE process is used for cold forming of large diameter steel line-pipes. Pipe strength has been found to increase (work hardening) or decrease (Bauschinger effect) after the UOE process compared to the plate depending on the steel grade, plate and pipe processing history. The steel chemistry, through the presence of microalloy precipitates, and prior processing, through the size and distribution of microalloy precipitates and presence of retained work hardening, affects the magnitude of the Bauschinger effect. In this paper the microstructures of two (Nb and Nb-V alloyed) steel plates, in terms of (Nb,V)(C,N) particle distributions and dislocation densities, have been related to the Bauschinger parameters in the as rolled and annealed initial conditions. The Bauschinger stress parameter increases with microalloy particle number density and dislocation density increase and the relative importance of the two effects is discussed

Mechanical property development during UOE forming of large diameter pipeline steels

Mechanical properties of large diameter welded steel pipes depend on the thermomechanically controlled rolled (TMCR) plate microstructure and UOE pipe-forming cold deformation sequence. Strength from plate to pipe may increase (work-hardening) or decrease (the Bauschinger effect). Bauschinger effect parameters depend on steel composition and plate processing history. The present study is examining two pipeline grades: X60 (Nb-alloyed) and X65 (Nb- and V-alloyed). Mechanical properties are determined by grain refinement, solid solution, precipitation strengthening mechanisms, and work-hardening (work-softening). The reverse deformation yield drop increases with an increase in the precipitate particle volume fraction and pre-strain. Annealing, leading to a decrease in the dislocation density, reduces the yield drop. The Bauschinger parameters are being quantitatively related to the particle type, size, and volume fraction, and the dislocation density

Role of the JIP4 scaffold protein in the regulation of mitogen-activated protein kinase signaling pathways

The c-Jun NH2-terminal kinase (JNK)-interacting protein (JIP) group of scaffold proteins (JIP1, JIP2, and JIP3) can interact with components of the JNK signaling pathway and potently activate JNK. Here we describe the identification of a fourth member of the JIP family. The primary sequence of JIP4 is most closely related to that of JIP3. Like other members of the JIP family of scaffold proteins, JIP4 binds JNK and also the light chain of the microtubule motor protein kinesin-1. However, the function of JIP4 appears to be markedly different from other JIP proteins. Specifically, JIP4 does not activate JNK signaling. In contrast, JIP4 serves as an activator of the p38 mitogen-activated protein (MAP) kinase pathway by a mechanism that requires the MAP kinase kinases MKK3 and MKK6. The JIP4 scaffold protein therefore appears to be a new component of the p38 MAP kinase signaling pathway

Recent trends in the climate of Namaqualand, a megadiverse arid region of South Africa

Abstract Namaqualand is especially vulnerable to future climate change impacts. Using a high-resolution (0.5°x0.5°) gridded data set (CRU TS 3.1) and individual weather station data, we demonstrated that temperatures as well as frequency of hot extremes have increased across this region. Specifically, minimum temperatures have increased by 1.4 °C and maximum temperatures by 1.1 °C over the last century. Of the five weather stations analysed, two showed evidence of a significant increase in the duration of warm spells of up to 5 days per decade and a reduction in the number of cool days (TX10P) by up to 3 days per decade. In terms of rainfall, we found no clear evidence for a significant change in annual totals or the frequency or intensity of rainfall events. Seasonal trends in rainfall did, however, demonstrate some spatial variability across the region. Spatial trends in evapotranspiration obtained from the 8-day MOD16 ET product were characterised by a steepening inland-coastal gradient where areas along the coastline showed a significant increase in evapotranspiration of up to 30 mm per decade, most notably in spring and summer. The increase in temperature linked with the increases in evapotranspiration pose significant challenges for water availability in the region, but further research into changes in coastal fog is required in order for a more reliable assessment to be made. Overall, the results presented in this study provide evidence-based information for the management of climate change impacts as well as the development of appropriate adaptation responses at a local scale

Prediction of RCF clustered cracks dimensions using an ACFM sensor and influence of crack length and vertical angle

Rolling contact fatigue (RCF) cracks are the predominant reason for rail grinding maintenance and replacement on all types of railway system, as they can potentially cause rail break if not removed. To avoid excessive material removal, accurate crack sizing is required. Alternating current field measurement has been used as an electromagnetic method for RCF crack sizing, incorporating with modelling results for single RCF cracks with large vertical angles (>30°). No study using this knowledge to size shallow angled crack clusters has yet been reported. A novel method, the pocket length compensation method, is proposed to determine the length and depth of RCF cracks with shallow vertical angles. For shallow crack clusters, vertical angle predictions are close to the measured values with a deviation of less than 13.6%. Errors in crack pocket length prediction are greatly reduced when the pocket length compensation was included. The predicted vertical depth using the approach developed for clustered angled cracks is accurate with errors <8.3%, which compares to errors of up to 60% if the single RCF crack approach is used and errors of up to 21.4% if a non-compensated prediction for crack clusters is used

Reduced Muscle Sympathetic Nerve Activity Response to a Cold Pressor Test in Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative autoimmune disease characterized by demyelination in the central nervous system leading to potential impairments in the autonomic control of cardiovascular function. We have previously demonstrated individuals with MS exhibit a diminished ability to increase blood pressure in response to a hypotensive stimulus compared with healthy controls likely due to impaired sympathetic modulation of the vasculature. PURPOSE: The aim of the current investigation was to test the hypothesis that muscle sympathetic nerve activity (MSNA) responses to a cold pressor test (CPT) are reduced in individuals with MS compared to healthy controls. METHODS: Four patients with relapsing-remitting MS (2 females/2 males, EDSS \u3c 4) and 4 sex-, age- and mass-matched controls were instrumented for MSNA (peroneal nerve), mean arterial blood pressure (MAP; Finometer), and heart rate (HR). Subjects were exposed to a CPT by immersing a hand in ice water for 2 min. Mean cardiovascular and MSNA responses (burst frequency) at baseline and at 30 sec intervals during the CPT were compared between groups. RESULTS: Heart rate (P\u3c0.001) and MAP (P\u3c0.001) responses increased from baseline throughout the CPT but no group differences were observed (P=0.10 and P=0.78, respectively). At baseline, MSNA was similar between groups (MS: 2 ± 2 vs. CON: 14 ± 9 bursts/min; P=0.239). However, individuals with MS had blunted MSNA responses to CPT compared to healthy controls at 60 seconds (MS: 18 ± 14 vs. CON: 42 ± 10 bursts/min; P=0.033), at 90 seconds (MS: 16 ± 12 vs. CON: 44 ± 10 bursts/min; P=.017) and at 120 seconds (MS: 13 ± 12 vs. CON: 43 ± 13 bursts/min; P=.012). CONCLUSION: Individuals with MS appear to have an attenuated muscle sympathetic response to CPT. However, MAP appears to respond similarly to healthy controls potentially through other compensatory mechanisms

Signal transduction cross talk mediated by Jun N-terminal kinase-interacting protein and insulin receptor substrate scaffold protein complexes

Scaffold proteins have been established as important mediators of signal transduction specificity. The insulin receptor substrate (IRS) proteins represent a critical group of scaffold proteins that are required for signal transduction by the insulin receptor, including the activation of phosphatidylinositol 3 kinase. The c-Jun NH(2)-terminal kinase (JNK)-interacting proteins (JIPs) represent a different group of scaffold molecules that are implicated in the regulation of the JNK. These two signaling pathways are functionally linked because JNK can phosphorylate IRS1 on the negative regulatory site Ser-307. Here we demonstrate the physical association of these signaling pathways using a proteomic approach that identified insulin-regulated complexes of JIPs together with IRS scaffold proteins. Studies using mice with JIP scaffold protein defects confirm that the JIP1 and JIP2 proteins are required for normal glucose homeostasis. Together, these observations demonstrate that JIP proteins can influence insulin-stimulated signal transduction mediated by IRS proteins

Exploring the genetic aetiology of trust in adolescents:Combined twin and DNA analyses

Behavioral traits generally show moderate to strong genetic influence, with heritability estimates of around 50%. Some recent research has suggested that trust may be an exception because it is more strongly influenced by social interactions. In a sample of over 7,000 adolescent twins from the United Kingdom’s Twins Early Development Study, we found broad sense heritability estimates of 57% for generalized trust and 51% for trust in friends. Genomic-relatedness-matrix restricted maximum likelihood (GREML) estimates in the same sample indicate that 21% of the narrow sense genetic variance can be explained by common single nucleotide polymorphisms for generalized trust and 43% for trust in friends. As expected, this implies a large amount of unexplained heritability, although power is low for estimating DNA-based heritability. The missing heritability may be accounted for by interactions between DNA and the social environment during development or via gene–environment correlations with rare variants. How these genes and environments correlate seem especially important for the development of trust

A single and rapid calcium wave at egg activation in Drosophila.

Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca(2+) concentration in mammals, ascidians and polychaete worms and a single Ca(2+) peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca(2+) levels occur. Here, we utilise ratiometric imaging of Ca(2+) indicator dyes and genetically encoded Ca(2+) indicator proteins to identify and characterise a single, rapid, transient wave of Ca(2+) in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca(2+) wave requires an intact actin cytoskeleton and an increase in intracellular Ca(2+) can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca(2+) wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca(2+) transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca(2+) at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca(2+) channels; a single Ca(2+) wave then propagates in an actin dependent manner; this Ca(2+) wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.This work was supported by the University of Cambridge, ISSF to T.T.W. [grant number 097814]; and Wellcome Trust Senior Research Fellowship to I.D. [grant number 096144].This is the final version of the article. It first appeared from the Company of Biologists via http://dx.doi.org/10.1242/bio.20141129