Explore the vast range of titles available.

Transcranial direct current stimulation (tDCS) increases primary motor cortex (M1) excitability and improves motor performance when applied unilaterally to the dominant hemisphere. However, the influence of tDCS on contralateral M1 excitability both during and after application has not been quantified. The purpose was to determine the influence of tDCS applied to the dominant M1 on the excitability of the contralateral non-dominant M1. This study employed a double-blind, randomized, SHAM-controlled, within-subject crossover experimental design. Eighteen young adults performed two experimental sessions (tDCS, SHAM) in counterbalanced order separated by a one-week washout. Transcranial magnetic stimulation (TMS) was used to quantify the excitability of the contralateral M1 to which anodal tDCS was applied for 20 min with a current strength of 1 mA. Motor evoked potential (MEP) amplitudes were assessed in 5 TMS test blocks (Pre, D5, D10, D15, and Post). The Pre and Post TMS test blocks were performed immediately before and after tDCS application, whereas the TMS test blocks performed during tDCS were completed at the 5, 10, and 15 min stimulation timepoints. MEPs were analyzed with a 2 condition (tDCS, SHAM) × 5 test (Pre, D5, D10, D15, Post) within-subject ANOVA. The main effect for condition (p = 0.213), the main effect for test (p = 0.502), and the condition × test interaction (p = 0.860) were all not statistically significant. These results indicate that tDCS does not modulate contralateral M1 excitability during or immediately after application, at least under the current set of common tDCS parameters of stimulation.

Virtually all aspects of cell biology are regulated by a ubiquitin code where distinct ubiquitin chain architectures guide the binding events and itineraries of modified substrates. Various combinations of E2 and E3 enzymes accomplish chain formation by forging isopeptide bonds between the C terminus of their transiently linked donor ubiquitin and a specific nucleophilic amino acid on the acceptor ubiquitin, yet it is unknown whether the fundamental feature of most acceptors—the lysine side chain—affects catalysis. Here, use of synthetic ubiquitins with non-natural acceptor site replacements reveals that the aliphatic side chain specifying reactive amine geometry is a determinant of the ubiquitin code, through unanticipated and complex reliance of many distinct ubiquitin-carrying enzymes on a canonical acceptor lysine. Using synthetic ubiquitins with non-natural acceptor site, the authors revealed that the length of lysine side chain in acceptor ubiquitins affects ubiquitin chain linkage specificity with native lysine as the preferred geometry.

American beech (Fagus grandifolia Ehrh.) trees resistant (R = 760) and susceptible (S = 681) to beech bark disease were located and mapped in nine natural stands in West Virginia (WV), Massachusetts (MA), Maine (ME), Nova Scotia (NS), and Prince Edward Island (PEI). Dormant bud tissue collected from each tree was examined by isozyme analysis to characterize the population genetic structure of R and S subpopulations mapped in each of four intensively sampled (R/S) stands, and five additional populations in which only R trees were sampled. Seventeen enzymes (with 9 polymorphic and 14 monomorphic loci) were analyzed to estimate variation across the spatial range of disease occurrence. All populations possessed significant levels of inter- and intra-population diversity; several parameters appeared to increase in magnitude from southwest to northeast across the range. In the R/S stands, percent polymorphic loci averaged 38%, average number of alleles/locus was 1.8 (3.0 for polymorphic loci), and mean expected heterozygosity was 0.165. Most genetic variation resided within populations (97%; G ST = 0.03). Analyses of pooled R and S subpopulations demonstrated that observed heterozygosities were up to 26% higher in S trees, i.e., R tree populations exhibited consistent heterozygote deficits.

A software project can be managed as a risky endeavor, and indeed this risk management approach is receiving increased attention in the software engineering literature. Published sources indicate that risk management is beginning to be applied to software development, not just as a set of techniques, but as a supervisory perspective for project management. However, in order to apply such an approach, solid tools are required for identifying, assessing, and managing project risks. This research has produced such a tool. A dynamic simulation model of software development was designed, implemented, and validated for the purpose of supporting management of particular risks to software projects. The process for developing the model included identification of significant software development risk factors, qualitative and quantitative studies of the effects of selected risk factors, experimentation with existing software development simulation models, development of a base model from existing sources, and extension of the base model with stochastically-modeled risk factors. This study extends previous research in both software development risk and in software process simulation. In the former area, the effects of selected major risk factors were studied and analyzed statistically. In the latter area, behavioral characterizations were derived from designed experiments on existing simulation models. The statistical results of the effects study and the behavioral characterizations were used to guide construction of a model designed for supporting management of selected project risks.

The average American is under-saved and under-insured: * Nearly 2 in 3 workers have less than $50,000 in savings and investments, with more than 1 in 4 reporting less than $1,000.3 * Nearly 7 in 10 have either no individual life insurance or not enough.4 * More than 2 in 3 private sector workers have no long-term disability income insurance.5 Differentiation is more challenging than ever because we're trying to hit a moving target. The industry has helped workers amass some $22 trillion in retirement assets, making the U.S. retirement system larger than the next nine largest systems combined.10 There are 109 million group life certificates, with a face amount of more than $8 trillion.11 There are also more than 44 million group long-term disability certificates.12 We're rethinking a lot of things and, importantly, putting the customer at the center of that rethinking. Houston is a member of several Boards, including Greater Des Moines Partnership, Employee Benefits Research Institute (EBRI), American Council of Life Insurers (ACLI), Financial Services Roundtable (FSR), Iowa State University Business School Dean's Advisory Council, Partnership for a Healthier America (PHA), and Reaching Higher Iowa. Houston joined the joint forum of U.S. Senate Committees on Finance and Health, Education, Labor and Pensions to discuss \"PrivateSector Retirement Savings Plans: What Does the Future Hold?\" He also authored a chapter in The Upside of Aging, published by John Wiley & Sons in 2014, on the keys to achieving financial security in retirement.

Position sensitive, high-purity germanium (HPGe) planar orthogonal strip detectors are currently being used for an increasing number of gamma imaging applications where high efficiency is required. Larger volume crystals are being employed to improve detection efficiency, and therefore, electrode signals show higher sensitivity to the charge spreading of clouds during the drift process. Signals are the result of energy deposition within the detector volume followed by the drift, diffusion, and repulsion of hole and electron charge clouds. The shape, amplitude, and timing of the signals on all electrodes yield position and energy information. In Compton imaging systems the accurate determination of interaction position and energy is of utmost importance. Current Compton imaging systems utilize event selection criteria that limit intrinsic efficiency due to the inability to resolve multiple interactions in close proximity or single interactions deposited across multiple electrodes. To address these limitations, a combination of Monte Carlo and finite element simulations has been developed to characterize signal shapes given initial conditions of position and energy. The signal generation model results are then compiled in order to perform signal decomposition of the majority of interaction event patterns to allow a higher intrinsic imaging efficiency as well as greater position resolution. The result of this methodology is a 3-fold increase in the position resolution from ∼1 mm down to 300-400 μm. Furthermore, the signal decomposition algorithm has shown robust position determination of events within 2 mm of one another. The effect of these advancements is an increase in the image quality and detection efficiency of Compton γ-ray imaging systems.

Fuel cell vehicles are entering the automotive market with significant potential benefits to reduce harmful greenhouse emissions, facilitate energy security, and increase vehicle efficiency while providing customer expected driving range and fill times when compared to conventional vehicles. One of the challenges for successful commercialization of fuel cell vehicles is transitioning the on-board fuel system from liquid gasoline to compressed hydrogen gas. Storing high pressurized hydrogen requires a specialized structural pressure vessel, significantly different in function, size, and construction from a gasoline container. In comparison to a gasoline tank at near ambient pressures, OEMs have aligned to a nominal working pressure of 700 bar for hydrogen tanks in order to achieve the customer expected driving range of 300 miles. Beyond the need to contain pressure, the hydrogen tanks also differ from gasoline fuel tanks because of the additional vehicle space needed due to the lower hydrogen energy volumetric density even with the highly efficient fuel cell (four times the external volume of a gasoline tank including the fuel cell efficiency benefit). The main difference and challenge of hydrogen tanks is the construction and design that depends on a high utilization of carbon fiber in order to reduce the weight of the pressure vessel although substantially increasing the cost. In 2012, the U.S. Department of Energy (DOE), Office of Fuel Cell Technologies recognized these challenges and initiated a project to research enhance materials and design parameters to reduce the cost of hydrogen storage tanks. The project was led by Pacific Northwest National Lab (PNNL) and involved several other organizations in the value chain of hydrogen tank development: AOC, Ford Motor Company, Hexagon Lincoln, and Toray CFA. The project took a holistic approach to improving performance by investigating: (1) composite matrix resin alternatives including adding nano-reinforcing particles and fiber-matrix sizing for improved adhesion, (2) carbon fiber alternatives, (3) tank design alternatives using hybrid fiber layups, and (4) opportunities with cold gas operating conditions to maintain the hydrogen density while reducing the tank composite utilization. In each of these areas, the project successfully identified the potential benefits: (1) demonstrated new resin with 50% cost reduction at equivalent or better performance than traditional epoxy, (2) identified 4% to 12% improvement with fiber alternatives, (3) developed validated tank design models with improved failure prediction capability, and (4) confirmed value and system level viability of cold gas storage with a combined 22% cost reduction opportunity. This paper examines these modifications and considers the outlook for on-board 700 bar compressed hydrogen tank systems to achieve the commercialization goals for fuel cell vehicles.

This research examined state-level developments within higher education governance in the last decade by focusing on the policy development processes and outcomes of two executive advisory groups' bids to shape public higher education policy. In the late 1990's Kentucky and Tennessee each established executive advisory boards to identify shortcomings in higher education and make recommendations to remedy perceived and real problems. Similar issues and action items were identified in each state, but the similarities in policy development ended when each state's policy entrepreneurs sought acceptance and adoption of their respective alternatives. Central to the research was an exploration of the external and internal factors influencing higher education policy and governance developments once policy alternatives are presented for adoption. Through case study, historical research, and interview methods, the research explored the similarities and differences between Kentucky and Tennessee that helped or hindered formal adoption of ideas or policy alternatives. The research aimed to identify what happened to bring issues and problems to prominence on the agenda in each state, but most importantly the study attempted to determine how and why some proposed solutions actually persisted to adoption and implementation. The interviews with key political and higher education figures provided insight into what factors kept proposals alive and contributed to their adoption. A proposed model of policy adoption made the assumption that all policy ideas upon becoming recognized as viable alternatives are heavily influenced by separate external and internal conditions and forces. Though reform initiatives in each of the study states were effected by several internal and external influences, the existence of a policy champion, the attention to political considerations, and acknowledgment of the significance of historical and cultural variables were of major importance.