Gz, a guanine nucleotide-binding protein with unique biochemical properties

Cloning of a complementary DNA (cDNA) for Gz alpha, a newly appreciated member of the family of guanine nucleotide-binding regulatory proteins (G proteins), has allowed preparation of specific antisera to identify the protein in tissues and to assay it during purification from bovine brain. Additionally, expression of the cDNA in Escherichia coli has resulted in the production and purification of the recombinant protein. Purification of Gz from bovine brain is tedious, and only small quantities of protein have been obtained. The protein copurifies with the beta gamma subunit complex common to other G proteins; another 26- kDa GTP-binding protein is also present in these preparations. The purified protein could not serve as a substrate for NAD-dependent ADP- ribosylation catalyzed by either pertussis toxin or cholera toxin. Purification of recombinant Gz alpha (rGz alpha) from E. coli is simple, and quantities of homogeneous protein sufficient for biochemical analysis are obtained. Purified rGz alpha has several properties that distinguish it from other G protein alpha subunit polypeptides. These include a very slow rate of guanine nucleotide exchange (k = 0.02 min^-1), which is reduced greater than 20-fold in the presence of mM concentrations of Mg2+. In addition, the rate of the intrinsic GTPase activity of Gz alpha is extremely slow. The hydrolysis rate (kcat) for rGz alpha at 30 degrees C is 0.05 min^-1, or 200-fold slower than that determined for other G protein alpha subunits. rGz alpha can interact with bovine brain beta gamma but does not serve as a substrate for ADP-ribosylation catalyzed by either pertussis toxin or cholera toxin. These studies suggest that Gz may play a role in signal transduction pathways that are mechanistically distinct from those controlled by the other members of the G protein family

Gluon polarization in the proton

We combine heavy-quark renormalization group arguments with our understanding of the nucleon's wavefunction to deduce a bound on the gluon polarization Delta g in the proton. The bound is consistent with the values extracted from spin experiments at COMPASS and RHIC.Comment: 4 page

Electrical characterization of the soft breakdown failure mode in MgO layers

The soft breakdown (SBD) failure mode in 20 nm thick MgO dielectric layers grown on Si substrates was investigated. We show that during a constant voltage stress, charge trapping and progressive breakdown coexist, and that the degradation dynamics is captured by a power-law time dependence. We also show that the SBD current-voltage (I-V) characteristics follow the power-law model I = aVb typical of this conduction mechanism but in a wider voltage window than the one reported in the past for SiO2. The relationship between the magnitude of the current and the normalized differential conductance was analyzed

The Impact of Information Technology Outsourcing on Firm Profitability Measures

Some researchers have concluded that outsourcing of information technology (IT) provides benefits to firms including cost advantages, economies of scale and allowing more of a focus on core competencies. This paper attempts to determine if these benefits actually exist by comparing three financial measures, return on equity (ROE), return on assets (ROA) and profit margin, affirms that have varying levels of outsourcing. To empirically test for the existence of a difference between firms that outsource differing amounts of IT spending, data from 104 companies was gathered. Analysis of variance was selected as the primary statistical tool to test the relationship between the level of outsourcing and the profitability measures. The results of this study lead to the conclusion that there is not a significant difference between the amounts of IT outsourcing companies perform and any of the profitability measures used during the sample period. Further discussion continues related to the implications of the results

Re-thinking uk transport emissions – Getting to the 2050 targets

Transport is a complex system, integral to national and international structure and without which society cannot function. At the same time, transport is a significant contributor to global greenhouse gas emissions. In the UK a step change is required in the transport sector to achieve the legally binding reduction targets of the Climate Change Act 2008. Following the UK government’s 2013 review of carbon dioxide emissions from infrastructure, this paper looks at the country’s present and projected transport emissions in the context of the transport status quo and plans for growth. It argues there is an urgent need to rebalance the transport modal mix, with all modes integrated into a seamless transport system with smart interfacing between them. Drivers for behavioural change are also essential.Engineering and Physical Sciences Research CouncilThis is the final version of the article. It first appeared from ICE Publishing via https://doi.org/10.1680/jcien.15.0007

Greenhouse gas considerations in rail infrastructure in the UK

Transportation-related greenhouse gas (GHG) emissions account for an increasing proportion of total emissions in the UK and globally. The provision of rail transit is popularly proposed to reduce transport GHG emissions, but the provision of new infrastructure is itself GHG intensive. Understanding of the GHG emissions impact of rail projects is limited and very few longitudinal studies have been carried out. Existing assessments are often limited both in their scope and the factors considered. A holistic understanding of GHG impacts must include an assessment of capital GHG emissions, operational energy and maintenance as well as an assessment of ridership mode shift and mode share impacts and the relationship between transit infrastructure and land use. This paper explores rail infrastructure projects and their associated GHG emissions. Guidance is given on the aspects of rail planning, design and construction that must be considered to more fully understand the associated GHG impacts.The authors would like to thank The Commonwealth Scholarship Commission in the UK for the scholarship funding that facilitated this work

Primary Beam Shape Calibration from Mosaicked, Interferometric Observations

Image quality in mosaicked observations from interferometric radio telescopes is strongly dependent on the accuracy with which the antenna primary beam is calibrated. The next generation of radio telescope arrays such as the Allen Telescope Array (ATA) and the Square Kilometer Array (SKA) have key science goals that involve making large mosaicked observations filled with bright point sources. We present a new method for calibrating the shape of the telescope's mean primary beam that uses the multiple redundant observations of these bright sources in the mosaic. The method has an analytical solution for simple Gaussian beam shapes but can also be applied to more complex beam shapes through $\chi^2$ minimization. One major benefit of this simple, conceptually clean method is that it makes use of the science data for calibration purposes, thus saving telescope time and improving accuracy through simultaneous calibration and observation. We apply the method both to 1.43 GHz data taken during the ATA Twenty Centimeter Survey (ATATS) and to 3.14 GHz data taken during the ATA's Pi Gigahertz Sky Survey (PiGSS). We find that the beam's calculated full width at half maximum (FWHM) values are consistent with the theoretical values, the values measured by several independent methods, and the values from the simulation we use to demonstrate the effectiveness of our method on data from future telescopes such as the expanded ATA and the SKA. These results are preliminary, and can be expanded upon by fitting more complex beam shapes. We also investigate, by way of a simulation, the dependence of the accuracy of the telescope's FWHM on antenna number. We find that the uncertainty returned by our fitting method is inversely proportional to the number of antennas in the array.Comment: Accepted by PASP. 8 pages, 8 figure

Shock tunnel studies of scramjet phenomena, supplement 6

Reports by the staff of the University of Queensland on various research studies related to the advancement of scramjet technology are presented. These reports document the tests conducted in the reflected shock tunnel T4 and supporting research facilities that have been used to study the injection, mixing, and combustion of hydrogen fuel in generic scramjets at flow conditions typical of hypersonic flight. In addition, topics include the development of instrumentation and measurement technology, such as combustor wall shear and stream composition in pulse facilities, and numerical studies and analyses of the scramjet combustor process and the test facility operation

Transdiagnostic treatment of bipolar disorder and comorbid anxiety using the Unified Protocol for Emotional Disorders: A pilot feasibility and acceptability trial

BACKGROUND Comorbid anxiety in bipolar disorder (BD) is associated with greater illness severity, reduced treatment response, and greater impairment. Treating anxiety in the context of BD is crucial for improving illness course and outcomes. The current study examined the feasibility, acceptability and preliminary efficacy of the Unified Protocol (UP), a transdiagnostic cognitive behavioral therapy, as an adjunctive treatment to pharmacotherapy for BD and comorbid anxiety disorders. METHODS Twenty-nine patients with BD and at least one comorbid anxiety disorder were randomized to pharmacotherapy treatment-as-usual (TAU) or TAU with 18 sessions of the UP (UP+TAU). All patients completed assessments every four weeks to track symptoms, functioning, emotion regulation and temperament. Linear mixed-model regressions were conducted to track symptom changes over time and to examine the relationship between emotion-related variables and treatment response. RESULTS Satisfaction ratings were equivalent for both treatment groups. Patients in the UP+TAU group evidenced significantly greater reductions over time in anxiety and depression symptoms (Cohen's d's>0.80). Baseline levels of neuroticism, perceived affective control, and emotion regulation ability predicted magnitude of symptom change for the UP+TAU group only. Greater change in perceived control of emotions and emotion regulation skills predicted greater change in anxiety related symptoms. LIMITATIONS This was a pilot feasibility and acceptability trial; results should be interpreted with caution. CONCLUSIONS Treatment with the UP+TAU was rated high in patient satisfaction, and resulted in significantly greater improvement on indices of anxiety and depression relative to TAU. This suggests that the UP may be a feasible treatment approach for BD with comorbid anxiety.This work was supported by a Postdoctoral National Research Service Award from the National Institutes of Health [F32 MH098490] to K. Ellard. (F32 MH098490 - Postdoctoral National Research Service Award from the National Institutes of Health)Accepted manuscrip