cssi/SciSciGPT-SciSciNet huggingface dataset:
Range shift and dose perturbation with high-density materials in proton beam therapy

Abstract Radiotherapy with proton beams requires accurate knowledge of the proton range. When materials with high atomic numbers ( Z ) and densities (e.g. prostheses or implants) are present in the patient, they give rise to pronounced uncertainties in computed tomography data and to large errors in proton range and dose calculations. A modified analytical expression is proposed for the observed range shift in water in the presence of a high-density material of known thickness and density. The expression was verified experimentally in a clinical beam with various thicknesses and materials in a water phantom, at several beam ranges and at different depths. Measurements were also made behind the medium-to-water interface to evaluate dose perturbation using a thin window parallel plate ion chamber. Primary particle fluence variations due to the range shift were studied in a separate experiment. The measured range shift was in good agreement (±0.3 mm) with the analytical expression for most of the materials studied. A small, but consistent dependence of range shift on the energy of impinging protons was found. Dose perturbation factor in water downstream of the material is less than +5% for thicknesses up to 8 g/cm 2 . The proposed analytical expression can be used in clinical situations to determine the range shift in patient caused by an implanted material. Dose perturbation in the presence of an implant is due to the changes in primary particle fluence resulting from several physical processes.
Major groove binding of the tRNA/mRNA complex to the 16 S ribosomal RNA decoding site

We propose a detailed three-dimensional model, with atomic detail, for the structure of the Escherichia coli 16 S rRNA decoding site in a complex with mRNA and the A and P-site tRNAs. Model building began with four primary assumptions: (1) A and P-site tRNA conformations are identical with those seen in the tRNA crystal structure; (2) A and P-site tRNAs adopt an S-type orientation upon binding mRNA in the ribosome; (3) A1492 and A1493 bind non-specifically to the mRNA through a series of hydrogen bonds; and (4) C1400 lies in close proximity to the P-site tRNA wobble base in order to satisfy a UV-induced photocrosslink formed between the two residues. We have models with both major groove and minor groove binding of the tRNA/mRNA complex to the decoding site RNA, and conclude that major groove binding is more likely. Both classes of models maintain structural features reported in the NMR structure of the A-site region of the decoding site RNA with bound paromomycin. We also present models for the tRNA/mRNA complex bound to the decoding site RNA in the presence of the aminoglycoside paromomycin. We discuss possible mechanisms for ribosomal proof reading and antibiotic disruption of this proofreading.
Biochemistry and Molecular Biology of Soybean Seed Storage Proteins

ABSTRACT Soybean (Glycine max[L.] Merr.) is one of the principle field crops grown in the United States. From a crop with no significant economic value at the turn of this century, soybeans have made remarkable strides in U.S. agriculture, claiming the stature of the number two U.S. cash crop. Soybean is an important source of edible vegetable oil and protein throughout the world and is used in a multitude of food and industrial applications. Even though soybeans are a rich source of protein for livestock and humans, the nutritional quality of soybean proteins is not optimal. Some of the problems associated with soybean proteins include (1) presence of anti-nutritional factors such as trypsin inhibitor, (2) undesirable beany flavor, (3) elicitation of allergic reactions in susceptible individuals, (4) poor digestibility of soybean proteins, and (5) deficiency in sulfur-containing amino acids. As a consequence, concerted efforts are underway to improve the overall nutritive value of soybean proteins by bot...
Testing the Effectiveness of iPad Math Game: Lessons Learned from Running a Multi-Classroom Study

Many educational products designed for young children go through extensive user testing, but rarely through a rigorous examination of whether they improve learning. We describe our experiences and lessons learned from conducting a multi-classroom study to examine learning from an iPad math app we developed for preschool and kindergarten children. Focusing on the research experience itself, we describe six common challenges to conducting learning research with technology and young children, as well as six principles to help mitigate the challenges. This paper is intended to help others who wish to assess learning from educational games for children.
Phase I trial of vinorelbine and diphenylhydantoin in patients with refractory carcinoma.

The anti-epileptic diphenylhydantoin (DPH; Dilantin®) selectively enhances the in vitro cytotoxicity of vinca microtubule poisons in both parent sensitive and multi-drug resistant (MDR) human tumor cells. The in vivo clinical activity of this combination has not been fully evaluated. Purpose: To determine the maximum tolerated dose (MTD), dose-limiting toxicities, and preliminary antitumor activity of the combination of intravenous (IV) bolus vinorelbine (VRL) and oral diphenylhydantoin (DPH) in patients (pts) with refractory solid tumors. Methods: Cohorts of 3–6 pts with refractory cancer were treated with escalating doses of weekly IV bolus VRL (I –20.0 mg/m2; II –22.5 mg/m2; III –25.0 mg/m2; IV –27.5 mg/m2; V –30.0 mg/m2; VI –32.5 mg/m2) combined with a fixed oral dose of DPH (400 mg/day) until MTD or progression. During each 35 day cycle, pts received DPH 400 mg/day administered orally on Days −6 to Day +22 and weekly IV bolus infusion of VRL on Days +1, +8, +15, and +22. The cohort treated at the MTD was expanded to further define toxicity. Results: A total of 25 evaluable pts. (9 men; 16 women) were treated with VRL and DPH at dose levels I (n = 5), II (n = 3), III (n = 2), IV (n = 3), V (n = 7) and VI (n = 5) in 5 week cycles over a 16 month period. Dose limiting toxicity occurred at dose level VI (VRL 32.5 mg/m2) and included grade 3 leukopenia (n = 2), grade 3 neutropenia (n = 1) and grade 4 neutropenia (n = 1) occurring within the first cycle of treatment. There were no responses, however 9 pts had stable disease of variable duration (8–56 weeks) and received a median of 2 cycles of treatment (range 2–14). Conclusion: Intravenous bolus administration of VRL and oral administration of a fixed dose of DPH was well tolerated according to the schedule reported here. Although there were no responses, several patients had prolonged disease stabilization. The recommended phase II dose of VRL when used in this combination is 30 mg/m2.
Research Spotlight: Soil temperature trends in Canada

[1] Global warming increasingly is becoming a concern for society. Most reported warming trends are based on measured increases in air temperatures. However, trends in soil temperatures, also an important indicator of climate change, are less often reported.Qian et al. analyzed soil temperature data from 30 climate stations across Canada covering the period from 1958 to 2008; the data cover soil temperatures at several depths up to 150 centimeters. They also analyzed air temperature, precipitation, and snow cover depth at the same locations. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2010JD015012, 2011)
Stability of symmetric film-splitting between counter-rotating cylinders

The ribbing instability, an extremely common cause of non-uniform liquid films in coating operations, is investigated both theoretically and experimentally. The Navier–Stokes system for the two-dimensional flow in symmetric film-splitting in forward roll coating is solved by finite-element analysis. Stability of the flow with respect to three-dimensional disturbances is examined by applying linear stability theory in a consistent finite-element approach, taking Fourier components in the transverse direction. The resulting generalized asymmetric eigenproblem is solved for the growth rates of disturbances as functions of wavenumber. The theory accurately predicts the critical capillary number and wavenumber at the transition to large-amplitude ribs. A sensitive experimental technique for detecting the ribs was developed that relies on low-angle reflection of a focused strip of white light off the meniscus between the rolls. This allowed detection of much smaller amplitude ribs, and much smaller critical capillary numbers were measured. The results indicate that the transition to ribbing is an imperfect bifurcation due to end effects, and clarify earlier discordances in the literature.
Pricing Residential Amenities: The Value of a View

This study provides estimates of the value of the view amenity in single-family residential real estate markets. A focus on Bellingham, Washington, a city with a variety of views, including ocean, lake, and mountain, allows for differentiation of the view amenity by both type and quality. Results from a hedonic model estimated for several recent years suggest that depending on the particular view, willingness to pay for this amenity is quite high. The highest-quality ocean views are found to increase the market price of an otherwise comparable home by almost 60%; the lowest-quality ocean views are found to add about 8%. For ocean views of all quality levels, the value of a view is found to vary inversely with distance from the water.
Flow in cyclic cosmology

In this paper, we use a known duality between expanding and contracting cosmologies to construct a dual of the inflationary flow hierarchy applicable to contracting cosmologies such as ekpyrotic and cyclic models. We show that the inflationary flow equations are invariant under the duality and therefore apply equally well to inflation or to cyclic cosmology. We construct a self-consistent small-parameter approximation dual to the slow-roll approximation in inflation, and calculate the power spectrum of perturbations in this limit. We also recover the matter-dominated contracting solution of Wands, and the recently proposed adiabatic ekpyrosis solution.
Synthesis of a β-Estradiol-Biotin Chimera that Potently Heterodimerizes Estrogen Receptor and Streptavidin Proteins in a Yeast Three-Hybrid System

Small molecules that dimerize proteins in living cells provide powerful probes of biological processes and have potential as tools for the identification of protein targets of natural products. We synthesized 7-alpha-substituted derivatives of beta-estradiol tethered to the natural product biotin to regulate heterodimerization of estrogen receptor (ER) and streptavidin (SA) proteins expressed as components of a yeast three-hybrid system. Addition of an estradiol-biotin chimera bearing a 19-atom linker to yeast expressing DNA-bound ER-alpha or ER-beta LexA fusion proteins and wild-type SA protein fused to the B42 activation domain activated reporter gene expression by as much as 450-fold in vivo (10 muM ligand). Comparative analysis of lower affinity Y43A (biotin Kd approximately 100 pM) and W120A (biotin Kd approximately 100 nM) mutants of SA indicated that moderate affinity interactions can be readily detected with this system. Comparison of a 7-alpha-substituted estradiol-biotin chimera with a structurally similar dexamethasone-biotin chimera revealed that yeast expressing ER proteins can detect cognate ligands with up to 5-fold greater potency and 70-fold higher activity than yeast expressing analogous glucocorticoid receptor (GR) proteins. This approach may facilitate the identification of protein targets of biologically active small molecules screened against genetically encoded libraries of proteins expressed in yeast three-hybrid systems.
Peak surface motion due to scattering of plane harmonic P, SV, or Rayleigh waves by a rough cavity embedded in an elastic half-space

Scattering of plane harmonic P, SV, or Rayleigh waves by a two-dimensional rough cavity completely embedded in an isotropic elastic half-space is investigated by using a direct boundary integral equation method. The cavity’s roughness is assumed to be in the form of periodic or random perturbations of arbitrary amplitude superimposed to a smooth elliptical shape. For the randomly corrugated cavities the normal or the uniform probability distribution functions are assumed. Based on multiple random cavity results, the corresponding average surface response is computed. These are compared with the corresponding periodically corrugated and smooth cavity responses. The surface response is evaluated for different cavity shapes and incident waves and for a range of frequencies. The surface motion results are used to determine the peak surface motion frequencies. They depend strongly upon the basic inclusion shape (the principal axes) and the nature of the incident wave. Strong similarity in the peak surface motion frequencies can be observed for the rough and smooth cavity models for both circular and elliptical shapes. In order to quantify the importance of the cavity corrugation upon the surface motion, a roughness influence factor is defined in terms of the rough and smooth cavity surface responses. This factor strongly depends upon the type of the incident wave, the nature of the cavity corrugation, the basic cavity shape, and the frequency. The factor clearly shows the effect of the cavity roughness upon the surface motion.
Symbolic computation of Hurwitz criterion

Maple procedures are written to evaluate Hurwitz determinants and to determine the stability of a control system. They also can be used to find the range of system parameters for a stable system. Examples are given.
Pool Boiling Experiments on a Nano-Structured Surface

The effect of nano-structured surfaces on pool boiling was investigated. Saturated and subcooled pool boiling experiments were performed on a horizontal heater surface coated with vertically aligned multiwalled carbon nanotubes (MWCNTs). MWCNTs were synthesized using the chemical vapor deposition (CVD) process. In this paper, MWCNT forests of two distinctly different heights (Type A: 9-mum height, and Type B: 25-mu m height) were synthesized separately on silicon wafers. PF-5060 was used as the test liquid. The results show that Type-B MWCNTs yield distinctly higher heat fluxes under subcooled and saturated conditions for both nucleate and film boiling. Type-A MWCNTs provide similar enhancement in nucleate boiling (as Type-B) for both saturated and subcooled conditions. Type-B MWCNTs enhanced critical heat flux (CHF) by 40%. Increasing the height of the MWCNTs is also found to extend the wall super heat required for CHF. In contrast, Type-A MWCNTs provide only marginal enhancement in film boiling compared to bare silicon wafer, for both saturated and subcooled film boiling. Type-B MWCNTs enhanced the heat flux in the film boiling regime for the Leidenfrost point by 175% (compared to bare silicon wafer).
Fall Contour Ripping Increases Water Infiltration into Frozen Soil

Crop residue management to trap snow and soil management to improve water infiltration into frozen soil might reduce spring runoff and increase soil water storage. We hypothesized that soil macropores created by tillage would improve water infiltration when the soil was frozen. This hypothesis was tested by ripping a Dooley sandy loam (fine-loamy, mixed Typic Argiboroll) in the fall of the year and then measuring water infiltration when the soil was frozen. A single subsoiling shank was used to rip soil to a depth of 0.3 m at 6-m contour intervals. Ripping was compared with no ripping using a randomized experimental design having three replications. Studies were conducted during 4 yr near Culbertson, MT, on plots seeded annually to spring wheat (Triticum aestivum L.). Soil water was measured with neutron attenuation and gravimetric methods. We used a constant-head (100 mm) method to measure water infiltration into frozen soil and a rainfall simulator for unfrozen soil. Final infiltration rate on frozen, ripped soil averaged 16 vs. 2 mm h - ' without ripping. Final unfrozen infiltration rate in spring was 34 mm h-' with ripping vs. 15 mm h - ' without ripping. Average spring water content of the top 1.2 m of soil, to a distance 1.5 m downslope from a rip, was 32 mm greater with ripping than without ripping at comparable slope positions. There were no wheat yield differences between treatments. Contour ripping can decrease water runoff, and seems best suited where spring runoff and soil erosion caused by heavy winter snows is a problem.
Amino acids necessary for DNA contact and dimerization imply novel motifs in the papillomavirus E2 trans-activator.

The bovine papillomavirus E2 protein regulates viral transcription by binding as a dimer to the DNA sequence ACCGN4CGGT. The dimerization and DNA-binding properties are localized within its carboxy-terminal 85 amino acids (325-410). Utilizing random mutagenesis coupled with phenotypic selection in yeast, functionally important amino acids in the DNA-binding domain were identified. Four trans-activation defective point mutants within a short segment (amino acids 337-344) were DNA binding defective but dimeric. The mutation of a conserved tryptophan to serine also eliminated DNA binding, but loss of dimerization was implicated because addition of dimeric monoclonal antibody complemented this defect. A simple assay for £2 dimerization was developed using UV irradiation to produce an interchain cross-link within a dimer. No heterodimeric complexes were formed when pools of E2 of varying lengths were mixed, and only proteins with tryptophan at position 360 could be UV cross-linked. Peptide mapping of irradiated E2 protein localized the cross-link to an 18-amino-acid region bracketing this tryptophan. Substitutions for this tryptophan demonstrated the requirement for a hydrophobic residue at this position, but surprisingly, even alanine was functional. Replacement of this tryptophan with three polar amino acids or glycine eliminated DNA-binding activity, but addition of dimeric monoclonal antibody restored this function. The amino acids that were identified as being involved in DNA contact and dimerization imply that these functions are mediated by novel binding motifs.
Spreading of partially coherent beams in random media

Some published computational work has suggested that partially coherent beams may be less susceptible to distortions caused by propagation through random media than fully coherent beams. In this paper this suggestion is studied quantitatively by examining the mean squared width of partially coherent beams in such media as a function of the propagation distance. The analysis indicates under what conditions, and to what extent, partially coherent beams are less affected by the medium.
Equity in the national rollout of public AIDS treatment in South Africa 2004-08.

Low- and middle-income country governments face the challenge of ensuring an equitable distribution of public resources based on need rather than socioeconomic status race or political affiliation. This study examines factors that may influence public service provision in developing countries by analysing the 2004-08 implementation of government-provided AIDS treatment in South Africa the largest programme of its kind in the world. Despite assurances from the National Department of Health some have raised concerns about whether the rollout was in fact conducted equitably. This study addresses these concerns. This is the first study to assemble high-quality national data on a broad set of census main place (CMP) characteristics that the public health economic and political science literature have found influence public service provision. Multivariate logistic regression and duration (survival) analysis were used to identify characteristics associated with a more rapid public provision of anti-retroviral therapy (ART) in South Africa. Overall no clear pattern emerges of the rollout systematically favouring better-off CMPs and in general the magnitude of statistically significant associations is small. The centralization of the early phases of the rollout to maximize ART enrolment led to higher ART coverage rates in areas where district and regional hospitals were located. Ultimately these results demonstrate that the provision of life-saving AIDS treatment was not disproportionately delayed in disadvantaged areas. The combination of a clear policy objective limited bureaucratic discretion and monitoring by civil society ensured equitable access to AIDS treatment. This work highlights the potential for future public investment in South Africa and other developing countries to reduce health and economic disparities. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine (c) The Author 2014; all rights reserved.
The influence of microtopography on soil nutrients in created mitigation wetlands.

This study explores the relationship between microtopography and soil nutrients (and trace elements), comparing results for created and reference wetlands in Virginia, and examining the effects of disking during wetland creation. Replicate multiscale tangentially conjoined circular transects were used to quantify microtopography both in terms of elevation and by two microtopographic indices. Corresponding soil samples were analyzed for moisture content, total C and N, KCl-extractable NH4‐N and NO3‐N, and Mehlich-3 extractable P, Ca, Mg, K, Al, Fe, and Mn. Means and variances of soil nutrient/element concentrations were compared between created and natural wetlands and between disked and nondisked created wetlands. Natural sites had higher and more variable soil moisture, higher extractable P and Fe, lower Mn than created wetlands, and comparatively high variability in nutrient concentrations. Disked sites had higher soil moisture, NH4‐N, Fe, and Mn than did nondisked sites. Consistently low variances (Levene test for inequality) suggested that nondisked sites had minimal nutrient heterogeneity. Across sites, low P availability was inferred by the molar ratio (Mehlich-3 [P/(Al 1 Fe)] < 0.06); strong intercorrelations among total C, total N, and extractable Fe, Al, and P suggested that humic‐metal‐P complexes may be important for P retention and availability. Correlations between nutrient/element concentrations and microtopographic indices suggested increased Mn and decreased K and Al availability with increased surface roughness. Disking appears to enhance water and nutrient retention, as well as nutrient heterogeneity otherwise absent from created wetlands, thus potentially promoting ecosystem development.
Review : Functional Neuroimaging of Memory

Cognitive neuroscientists have acquired powerful new tools for studying the functional neuroanatomy of the human brain. Traditional methods such as lesion analysis have been supplemented with electrical and mag netic field recording techniques that can measure the informational transactions of the brain in the scale of milliseconds and neuroimaging techniques that can provide structural details of the brain to a fraction of a millimeter. The most powerful new methods have been functional imaging techniques in which brain activity engendered by a sensory, motor, or cognitive task causes an increase in local blood flow and metabolism that can be imaged with high resolution. This article reviews recent progress in functional neuroimaging, with special emphasis on understanding the neural substrates of memory. The Neuroscientist 1:155-163, 1995
A novel matching criterion and low power architecture for real-time block based motion estimation

In recent years, minimizing the power consumption has become a key issue in the design of portable electronic devices. In this paper, low power architecture which can support the real time motion estimation of video signals is presented. The architecture is based on a binary level matching criterion which performs a bit-wise comparison. The processor level design based on simple combinational logic using the binary level matching criterion has been introduced. Compared with the existing architectures, the proposed architecture delivers higher throughput rate, requires fewer input/output lines, and reduces the total power consumption.
The CNN universal machine. II. Programmability and applications

For pt.I, see ibid., p.1-10 (1992). The programmability (as a stored program) of the CNN universal machine is discussed. It is shown why and in which sense this machine is universal. The analogic type of algorithm is introduced. The application potential is reviewed and the biological relevance is analyzed. It is shown that the architecture is optimal not only for silicon implementations, but also for many biological information processing organs that have the same structure. >
Temperature dependence of 4f PES features and hole occupancy in yterbium heavy fermions

Abstract We have measured the temperature dependence between 80 and 300 K and spectral weight of the 4f features in clean single crystal Yb heavy fermions, cleaved in a vacuum of 5 × 10−11 Torr. A small (∼ 15%) decrease in spectral weight differs substantially from the reported ∼ 50% decrease over this range. All divalent features are much larger than expected, yielding nf values far too small. The intensity of the divalent features in YbAuCu4 is about two orders of magnitude larger than expected.
Calcium-dependent block of P2X7 receptor channel function is allosteric.

Among purinergic P2X receptor (P2XR) channels, the P2X7R exhibits the most complex gating kinetics; the binding of orthosteric agonists at the ectodomain induces a conformational change in the receptor complex that favors a gating transition from closed to open and dilated states. Bath Ca2+ affects P2X7R gating through a still uncharacterized mechanism: it could act by reducing the adenosine triphosphate4− (ATP4−) concentration (a form proposed to be the P2X7R orthosteric agonist), as an allosteric modulator, and/or by directly altering the selectivity of pore to cations. In this study, we combined biophysical and mathematical approaches to clarify the role of calcium in P2X7R gating. In naive receptors, bath calcium affected the activation permeability dynamics indirectly by decreasing the potency of orthosteric agonists in a concentration-dependent manner and independently of the concentrations of the free acid form of agonists and status of pannexin-1 (Panx1) channels. Bath calcium also facilitated the rates of receptor deactivation in a concentration-dependent manner but did not affect a progressive delay in receptor deactivation caused by repetitive agonist application. The effects of calcium on the kinetics of receptor deactivation were rapid and reversible. A438079, a potent orthosteric competitive antagonist, protected the rebinding effect of 2’(3′)-O-4-benzoylbenzoyl)ATP on the kinetics of current decay during the washout period, but in the presence of A438079, calcium also increased the rate of receptor deactivation. The corresponding kinetic (Markov state) model indicated that the decrease in binding affinity leads to a decrease in current amplitudes and facilitation of receptor deactivation, both in an extracellular calcium concentration–dependent manner expressed as a Hill function. The results indicate that calcium in physiological concentrations acts as a negative allosteric modulator of P2X7R by decreasing the affinity of receptors for orthosteric ligand agonists, but not antagonists, and not by affecting the permeability dynamics directly or indirectly through Panx1 channels. We expect these results to generalize to other P2XRs.
Beliefs about unmet interpersonal needs mediate the relation between conflictual family relations and borderline personality features in young adult females

Background: Central to most theories of borderline personality disorder (BPD) is the notion that the family environment interacts with genetically-based vulnerabilities to influence the development of BPD, with particular attention given to risk conferred by conflictual familial relations. However, the extent to which family conflict may relate to the development of BPD via related interpersonal beliefs is currently unknown. This study sought to test the hypothesis that the concurrent relation between conflictual family relations and borderline features in female college students is explained by beliefs associated with real or perceived unmet interpersonal needs (captured by Joiner’s [2005] Interpersonal Psychological Theory, specifically thwarted belongingness and perceived burdensomeness). Method: The sample included 267 female undergraduates ages 18–25 years (M= 20.86; SD = 1.80). Level of borderline personality features, unmet interpersonal needs, and family conflict were assessed. Results: Bivariate analyses revealed significant relations between both thwarted belongingness and perceived burdensomeness, conflictual family relations, and borderline features. Multivariate analyses revealed that thwarted belongingness and perceived burdensomeness both mediated the relation between family conflict and borderline personality features, thus supporting a multiple mediation model. Conclusions: This cross-sectional study is a preliminary step towards confirming the broad theoretical hypothesis that conflictual family relations relate to beliefs about thwarted belongingness and perceived burdensomeness, which, in turn, relate to borderline personality pathology. Limitations and areas of future research are discussed.
Frameshift mutations in rdxA and metronidazole resistance in North American Helicobacter pylori isolates

In Helicobacter pylori, the oxygen-insensitive nitroreductase RdxA is likely to activate metronidazole (Mtz) by reduction and formation of cytotoxic intermediates. Mutations in rdxA have been associated with Mtz resistance in H. pylori. In vitro Mtz susceptibilities of 17 randomly selected H. pylori isolates were determined by the agar dilution method. DNA sequence analysis of rdxA alleles of eight susceptible isolates (MIC range: 0.25‐1.0 mg/L) and nine resistant isolates (MIC range: 16‐256 mg/L) showed that six of nine Mtz-resistant H. pylori isolates contained insertion or deletion mutations (‘indel’ mutations). One isolate contained a substitution mutation at codon position 148 that resulted in the introduction of a premature stop codon. Creation of stop codons within the rdxA coding sequence by either frameshift or substitution mutations resulted in premature translation termination and expression of putatively truncated RdxA polypeptides.
In vivo imaging of molecular targets and their function in endocrinology

Imaging is one of the fastest growing fields of study. New technologies and multimodal approaches are increasing the application of imaging to determine molecular targets and functional processes in vivo. The identification of a specific target, transporter, or biological process using imaging has introduced major breakthroughs to the field of endocrinology primarily utilizing computed tomography, magnetic resonance imaging, ultrasonography, positron emission tomography, single-photon emission computed tomography, and optical imaging. This review provides a general background to the specific developments in imaging that pertains to in vivo function and target identification in endocrine-based diseases.
Bulk current injection testing of cable noise reduction techniques, 50 kHz to 400 MHz

This paper presents empirical results of cable noise reduction techniques as demonstrated using bulk current injection (BCI) techniques with radiated fields from 50 kHz — 400 MHz. It is a follow up to the two-part paper series presented at the Asia Pacific EMC Conference that focused on TEM cell signal injection. This paper discusses the effects of cable types, shield connections, and chassis connections on cable noise. For each topic, well established theories are compared with data from a real-world physical system.
Learning semantic visual vocabularies using diffusion distance

In this paper, we propose a novel approach for learning generic visual vocabulary. We use diffusion maps to automatically learn a semantic visual vocabulary from abundant quantized midlevel features. Each midlevel feature is represented by the vector of pointwise mutual information (PMI). In this midlevel feature space, we believe the features produced by similar sources must lie on a certain manifold. To capture the intrinsic geometric relations between features, we measure their dissimilarity using diffusion distance. The underlying idea is to embed the midlevel features into a semantic lower-dimensional space. Our goal is to construct a compact yet discriminative semantic visual vocabulary. Although the conventional approach using k-means is good for vocabulary construction, its performance is sensitive to the size of the visual vocabulary. In addition, the learnt visual words are not semantically meaningful since the clustering criterion is based on appearance similarity only. Our proposed approach can effectively overcome these problems by capturing the semantic and geometric relations of the feature space using diffusion maps. Unlike some of the supervised vocabulary construction approaches, and the unsupervised methods such as pLSA and LDA, diffusion maps can capture the local intrinsic geometric relations between the midlevel feature points on the manifold. We have tested our approach on the KTH action dataset, our own YouTube action dataset and the fifteen scene dataset, and have obtained very promising results.
Evolutionary Dynamics of Rhodopsin Type 2 Opsins in Vertebrates

Among the five groups of visual pigments in vertebrates, the rhodopsin type 2 (RH2) group shows the largest number of gene duplication events. We have isolated three intact and one nonfunctional RH2 opsin genes each from Northern lampfish (Stenobrachius leucopsarus) and scabbardfish (Lepidopus fitchi). Using the deduced amino acid sequences of these and other representative RH2 opsin genes in vertebrates, we have estimated the divergence times and evolutionary rates of amino acid substitution at various stages of RH2 opsin evolution. The results show that the duplications of the lampfish and scabbardfish RH2 opsins have occurred approximately 60 and approximately 30 million years ago (Ma), respectively. The evolutionary rates of RH2 opsins in the early vertebrate ancestors were approximately 0.25 x 10(-9)/site/year, which increased to approximately 1 x 10(-9) to 3 x 10(-9)/site/year in euteleost lineages and to approximately 0.3 x 10(-9) to 0.5 x 10(-9)/site/year in coelacanth and tetrapods.
VoIP on Wireless Meshes: Models, Algorithms and Evaluation

We study the problem of supporting VoIP calls in a wireless mesh network. Specifically, we propose solutions for call admission control (CAC) and route selection for VoIP calls. Call admission decisions must evaluate how the capacity of the mesh network is utilized by the existing calls. We address this issue via a measurement-based modeling effort to model mutual interference between wireless links. The modeling approach evaluates whether capacity constraints (or, required QoS metrics) will be satisfied if a new call is admitted with a given route. Evaluations with a 6-node 802.11a testbed demonstrate excellent accuracy of the model and thus also the CAC performance. We address the issue of route selection by also using a modeling approach that considers models of transmission and interference ranges to develop a polynomial-time algorithm to search for feasible routes. This problem takes exponential time for wireless networks without such modeling. In addition to studying feasibility, we study several routing metrics such as shortest feasible path and maximum residual feasible path. Finally, we develop a new method for routing using call statistics that uses prior calling patterns to avoid potentially critical links. We evaluate the performance of these route selection techniques via extensive simulations and demonstrate the superiority of using max residual feasible path over simply shortest feasible path, and routing using call statistics over max residual feasible path.
Academic Accountability In Texas Public Schools: 2003-2007

This study examines factors affecting test scores in a sample of thirty-seven Texas public high schools from 2003 to 2007 since the implementation of the No Child Left Behind (NCLB) Act of 2001. The schools were chosen based upon similar tax rates and district sizes. The Texas Assessment of Knowledge and Skills (TAKS) test was implemented in 2003 to measure the performance of Texas public high school students. Schools are rewarded for high performance based upon the student scores on the TAKS test, which is administered once per year. Much of the debate on student and school accountability has centered on the importance of student performance on the standardized TAKS test. Those who oppose testing say that teachers and administrators may simply narrow the curriculum and teach the test. Proponents of testing feel that accountability will give administrators and teachers incentives to help students learn. As a result, many school districts in Texas have increasingly put pressure on teachers to improve test scores.
Educational dialogue and technological utterances: a phenomenological approach to developing a theory of evocative design practice

Online and distance education presents many challenges for both educators and system designers. The nature of these challenges is given particular clarity when examining online education in respect to pedagogical approaches which emphasize the importance of dialogue as part of the educational process. In order to begin to understand the dialogic role that technology plays in online education, a phenomenologically-oriented conceptual framework is sketched out. Taking computer interactions to be structured largely as interpretive processes that occur within a wider cultural context, the role of online educational systems in instructor-student dialogue is presented as a form of technological utterance, able to both sustain, as well as instantiate, messages in a dialogue between students and instructors. Introducing questions for future research, the aim is to develop design theory for both the design of online education as well as for design in general.
Intent to Enhance Information Systems as a Function of System Success

This study develops a theory for selecting a criterion measure that is functionally related to information systems success. This criterion is a decision maker's intention to enhance a current information system. The generalized (non-quantitative) form of the cost/benefit principle is employed to advance hypotheses that examine the predictive validity of alternative indicators of perceived information systems success. The results of the study suggest that the usefulness of a system as perceived by its users and the perceived cost of the intended change in an information system are significant predictors of future development intentions. The quality of output information perceived by users was not strongly related to development intentions.
Introgression of the low browning trait from the wild Mexican species Solanum hjertingii into cultivated potato (S. tuberosum L.)

Internal discoloration of tubers resulting from impact damage (blackspot bruise) is a serious quality problem in potato production and utilization, reducing profits to growers and increasing costs for processors. Resistance to blackspot bruise has been identified in the wild species Solanum hjertingii and is therefore a potential germplasm resource for genetic resistance to this problem. A bridging cross between S. hjertingii and a cultivated diploid clone was used to produce a triploid hybrid population that exhibited very low tuber browning potential, indicating a dominant pattern of inheritance for this trait. The triploid progeny were subjected to in vitrochromosome doubling and the resulting hexaploid clones were screened for browning potential. A hexaploid clone selected for low browning was reciprocally crossed with cultivated S. tuberosum cultivars exhibiting high susceptibility to blackspot bruise. Tubers obtained from the seed progeny of these 4x-6x crosses (hereafter referred to as the BC1 populations) were evaluated for browning potential and polyphenol oxidase (PPO) activity. Tubers from the BC1 populations displayed a very low potential for melanin production, while PPO activity was quite variable. The low Pearson correlation coefficient (r2 = 0.45), between browning potential and PPO activity suggests that the mechanism of blackspot bruise resistance derived from S. hjertingii cannot be explained simply as a reduction in the initial PPO activity. The expression of substantial resistance to browning and dominant expression pattern in these BC1 progeny indicate that utilizing genetic elements derived from S. hjertingii provides a robust approach for developing blackspot bruise resistant potato varieties.
Ultrafast Lasers enable Next Generation Batteries

We present on a high-speed laser structuring technique, which enables a significant improvement of electrode and separator wetting and battery performance and revealed higher capacities and increased cycle numbers compared to standard cells.
Transitioning Data Flow-Based Visualization Software to Multi-core Hybrid Parallelism

Many of today's programs for supercomputers are designed for distributed-memory parallelism, but not for shared-memory parallelism. As architectural trends for supercomputers suggest an ever-increasing number of cores per node, these projects must evaluate whether they can benefit from hybrid parallelism - parallelism that blends distributed- and shared-memory approaches - and whether the costs for migrating to new architectures are prohibitive. With this research effort, we explore whether a data flow-based visualization tool could be easily migrated to a hybrid parallel setting, what the challenges are, and what benefits hybrid parallelism achieves. For results, we find that only a relatively small investment was required to transition the tool and it significantly improves performance and also reduces memory usage and communication costs.
Nitroimidazole-Indocynine Green Conjugates for Breast Cancer Hypoxia Imaging

We present the optical properties of new nucleophilic imidazole compounds synthesized for tumor hypoxia imaging. The photophysical and hypoxic properties of these new molecules are evaluated and targeted for imaging breast cancer hypoxia.
Reaction of soluble penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus with beta-lactams and acyclic substrates: kinetics in homogeneous solution.

The kinetics of reaction of solubilized penicillin-binding protein 2a (sPBP2a) of methicillin-resistant Staphylococcus aureus with a variety of beta-lactams and acyclic species was studied in homogeneous aqueous solution at 37 degreesC in 25 mM Hepes buffer, pH7.0, containing 1 M NaCl. Under these conditions, but not at lower salt concentrations, protein precipitation did not occur either during or after the reaction. The reactions of beta-lactams in general could be monitored by competition with a chromophoric beta-lactam, nitrocefin, or directly in certain cases by protein fluorescence. Rate constants for reaction of a wide variety of beta-lactams are reported. The interactions are characterized by a slow second-order acylation reaction followed by a slower deacylation. For example, the rate constants for benzylpenicillin were 12 M-1.s-1 and 3x10(-5) s-1 respectively. The acylation is slow in comparison with those of normal non-resistant high-molecular-mass penicillin-binding proteins. sPBP2a also seemed to catalyse the slow hydrolysis of a variety of acyclic depsipeptides but not that of a d-Ala-d-Ala peptide. The reactions with certain depsipeptides also led to protein precipitation. These reactions were, however, not affected by prior blockage of the beta-lactam-binding site by benzylpenicillin and thus might take place elsewhere on the enzyme. Two classes of potential transition- state analogue inhibitors, phosphonate monoesters and boronates, seemed to have little effect on the rate of reaction of sPBP2a with nitrocefin and therefore seem to have little affinity for the beta-lactam-binding/D,D-peptidase site.
Cope, oxy-Cope, and anionic oxy-Cope rearrangements

The Cope, oxy-Cope, and anionic oxy-Cope rearrangements belong to the category of [3,3]-sigmatropic rearrangements, which is a concerted process. The arrow-pushing here is only illustrative.
An Application Method of Issuing Security Tasks for Power Information Collection System

Aiming at the problem of issuing security tasks for power information collecting system, a security hardware system and its application method has been designed. This security issuing system consists of a main data station, all the Watt-hour-meters which receive its controlling messages, and terminal units. The method includes the memory of the tasks and its transfer. In this article, an application way of issuing security tasks for power information collecting system is presented. By adding and transferring recognition codes in the terminal units, the right of terminal units to issue tasks is under control and being limited, which will solve the problem of illegal visits to main station and its meters beneath. Meanwhile, it prevents all kinds of attacks of task information from any attacker by mean of adding security recognition between the terminals and Watt-hour meters.
Service-learning project for computing students: Creating a mobile app for a non-profit agency

Over the last 15 years the world as seen a surge in users owning smartphones and electronic devices. People today have smartphones that have the computational capabilities of computers from more than 45 years ago. With the growing populous under this information age, individuals have access to so much data. It is a fantastic time to spread ideas as anyone can reach anybody else over the internet almost instantaneously. It is not too difficult to get into contact with anyone even if they are on the other side of the globe. This is the power of the 21st century and which has generated a team-oriented society. With this team based structure, people are looking more and more into ways to better manage groups of people, divide up tasks, and share a barrage of emails between one another.
The Emperor’s New Information Economy

According to the U.S. Commerce Department, 1990 was the first year in which capital spending relevant to the information economy (computers and telecommunications) exceeded capital spending on the more traditional aspects of the industrial infrastructure (plant, equipment, physical transportation, etc.). Many scholars and business-oriented commentators have greeted these data as evidence that the U.S. economy is now firmly rooted in the information age, that a new “information economy” has replaced the industrial economy that dominated most of the twentieth century.