cssi/SciSciGPT-SciSciNet huggingface dataset:
Hard-sphere-chain equations of state for lyotropic polymer liquid crystals

Abstract Using Parsons-type scaling, the Onsager theory for the isotropic–nematic (I–N) transition of rigid-rod lyotropic polymer liquid crystals is combined with the equation of state for hard-sphere-chain fluids of Chapman et al. and that of Hu et al. The equation of Hu et al. gives the I–N transition pressure and density in good agreement with computer simulation by Wilson and Allen for a semi-flexible hard-sphere chain consisting of seven segments. For real semi-flexible polymers, we follow the Khokhlov–Semenov theory of persistent chains that introduces chain flexibility into the Onsager theory. Using a consistent procedure to regress the equation-of-state parameters, the equations of Chapman et al. and Hu et al. are also compared with the theory of DuPre and Yang that uses the equation of Lee for hard spherocylinders. These models are compared with experiment for two binary polymer solutions containing poly(hexyl isocyanate) and another solution containing polysaccharide schizophyllan. The concentration of polymer at the I–N transition is predicted as a function of the molecular weight of polymer. All models perform similarly and show semi-quantitative agreement with experiment.
Comparison of Metallographic and X-Ray Measurements of Retained Austenite

THE martensite reaction in steels has been studied by microscopic examination of polished and etched samples after the samples have been tempered for short periods of time. One etching reagent which has been used is a solution of 6 per cent nitric acid in alcohol, which is called 6 per cent nital. This etchant stains the martensite grey or black and leaves the austenite white.
Mechanism of Intrinsic Transcription Termination and Antitermination

Gene expression is modulated by regulatory elements that influence transcription elongation by RNA polymerase: terminators that disrupt the elongation complex and release RNA, and regulators that overcome termination signals. RNA release from Escherichia coli RNA polymerase can be induced by a complementary oligonucleotide that replaces the upstream half of the RNA hairpin stem of intrinsic terminator transcripts, implying that RNA hairpins act by extracting RNA from the transcription complex. A transcription antiterminator inhibits this activity of oligonucleotides and therefore protects the elongation complex from destabilizing attacks on the emerging transcript. These effects illuminate the structure of the complex and the mechanism of transcription termination.
Internal preference mapping of hedonic ratings for Ranch salad dressings varying in fat and garlic flavor

Abstract Product users and likers tasted and rated samples of Ranch salad dressing (a viscous, buttermilk-based dressing high in dairy, onion, garlic, and pepper flavors) varying in fat and garlic flavor according to a 3 2 factorial design for liking of texture/mouthfeel, flavor (taste and smell) and overall degree of liking. Data was analyzed first by analysis of variance (ANOVA), multiple mean comparisons (Fisher’s LSD) and response surface methodology (RSM) to examine trends for the consumer population as a whole, and then by internal preference mapping to examine individual consumer preferences. Whereas the first set of techniques showed small differences among the mean ratings of the samples, a wide range of consumer preferences was observed in the preference maps. As the level of garlic flavor increased, liking increased, especially among women. Fat content did not drive liking as strongly as garlic flavor. The texture of the high-fat samples was liked the least. This study emphasizes the usefulness of preference mapping of a sample set prepared according to a factorial design and confirms the value of examining individual consumers as well as average population trends. ©
Properties, units and constants in magnetism

Data and numbers designed to be useful as a pocket data card for workers in the fields of magnetism and magnetic materials.
Minimum bias priors for estimating parameters of additive terms in state-space models

We treat the problem of estimating parameters of additive terms, sometimes called bias terms, in state-space models. We consider models that depend linearly on the state but possibly nonlinearly on the parameters, where both the state and observation are corrupted by additive noise. A prior density for the parameters is introduced that, when combined with the likelihood function to form a posterior density, minimizes the bias of the posterior mean. The result is a useful prior based on ignorance. Two examples and simulations illustrate the use of the prior. >
Grain Expansion and Subsequent Seeded Growth of AlN Single Crystals

Ongoing efforts of growing large AlN single crystals at NCSU using an induction-heated, high-temperature reactor are based on (1) engineered expansion of single crystalline grains with increasing boule length, as well as (2) the development of a growth process that enables seeded growth on AlN surfaces previously exposed to air. The growth process is based on physical vapor transport (PVT), where AlN powder is sublimed in a high purity nitrogen atmosphere. The growth temperature was typically in the range of 2250 to 2300 °C. In this study, tungsten crucibles were used in combination with graphite insulation and were found to be durable for AlN growth. Boule growth was interrupted several times in order to refill the AlN powder source and the growth surface was subjected to surface preparation to facilitate epitaxial re-growth. Grain expansion was studied as a function of process parameters. Crystalline quality of large single crystalline grains was correlated with their surface morphology.
Determination of 9-cis β-carotene and ζ-carotene in biological samples

Concentrations of 9-cis beta-carotene (9-cis betaC) and zeta-carotene (zetaC) in biological samples may provide crucial information on the biological activities of these carotenoids. However, in high-performance liquid chromatography (HPLC) these carotenoids are often co-eluted. Therefore, there is an urgent need to develop a method for 9-cis betaC and zetaC quantitation. Both 9-cis betaC and zetaC have peak absorbance at 400 and 450 nm, respectively, whereas only 9-cis betaC has peak absorbance at 475 nm. We developed a HPLC method to quantitate 9-cis betaC and zetaC by using peak absorbance ratios. The 9-cis betaC/zetaC peak area was monitored at 475, 450 and 400 nm. The 9-cis betaC was quantified by using absorbance value at 475 nm; zetaC was then calculated from the 9-cis betaC/zetaC peak at 400 nm by subtracting 9-cis betaC contribution at 400 nm using the 400-nm/475-nm peak absorbance ratio of 9-cis betaC (0.39). This method was applied to determine 9-cis betaC and zetaC concentrations in serum and breast milk samples (n=12) from American lactating women and serum and breast adipose tissue samples (n=16) from Korean women with either benign or malignant breast tumors. 9-cis betaC concentrations in serum and breast milk of American women, and serum and adipose tissue of Korean women were 7.1+/-0.8 and 1.1+/-0.2 nM, and 15.6+/-1.1 nM and 0.2+/-0.1 nmol/g, respectively. zetaC concentrations in the above samples were 54.2+/-7.2 and 8.3+/-1.8 nM, and 49.0+/-3.9 nM and 0.3+/-0.1 nmol/g, respectively.
Unique prognostic factors in acral lentiginous melanoma.

Abstract Background This study was performed to identify clinicopathologic factors associated with survival in acral lentiginous melanoma. Methods A post hoc analysis of a prospective clinical trial and local database was performed in all patients with acral lentiginous melanomas. Multivariate analyses of factors associated with a tumor-positive sentinel lymph node (SLN) biopsy, disease-free survival (DFS), overall survival (OS), and local and in-transit recurrence-free survival (LITRFS) were performed. Kaplan–Meier survival analyses were performed. Results Eighty-five patients were identified. Age younger than 59 years and Breslow thickness (BT) of 2.0 mm or greater were independent risk factors for a positive SLN. SLN status was the only independent risk factor for DFS and LITRFS on multivariate analysis. A BT of 2.0 mm or greater was the only independent risk factor for OS. SLN status distinguished differences in DFS, OS, and LITRFS on Kaplan–Meier analysis. Conclusions SLN status is the dominant factor for recurrence and survival in acral lentiginous melanoma. BT and ulceration are less important in this histologic subtype.
Radial Void Fraction Distributions in Randomly Packed Fixed Beds of Uniformly Sized Spheres in Cylindrical Containers

Abstract The angular void fraction distribution in randomly packed fixed beds of uniformly sized spheres in cylindrical containers is analyzed by a nondestructi
A personal reflection on the history of radiation oncology at Memorial Sloan-Kettering Cancer Center.

Purpose To provide a historical and personal narrative of the development of radiation oncology at Memorial Sloan-Kettering Cancer Center (MSKCC), from its founding more than 100 years ago to the present day. Methods and Materials Historical sources include the Archives of MSKCC, publications by members of MSKCC, the author's personal records and recollections, and her communications with former colleagues, particularly Dr. Basil Hilaris, Dr. Zvi Fuks, and Dr. Beryl McCormick. Conclusions The author, who spent 38 years at MSKCC, presents the challenges and triumphs of MSKCC's Radiation Oncology Department and details MSKCC's breakthroughs in radiation oncology. She also describes MSKCC's involvement in the founding of the American Society for Therapeutic Radiology and Oncology.
Two approaches to understanding when constraints help clustering

Most algorithm work in data mining focuses on designing algorithms to address a learning problem. Here we focus our attention on designing algorithms to determine the ease or difficulty of a problem instance. The area of clustering under constraints has recently received much attention in the data mining community. We can view the constraints as restricting (either directly or indirectly) the search space of a clustering algorithm to just feasible clusterings. However, to our knowledge no work explores methods to count the feasible clusterings or other measures of difficulty nor the importance of these measures. We present two approaches to efficiently characterize the difficulty of satisfying must-link (ML) and cannot-link (CL) constraints: calculating the fractional chromatic polynomial of the constraint graph using LP and approximately counting the number of feasible clusterings using MCMC samplers. We show that these measures are correlated to the classical performance measures of constrained clustering algorithms. From these insights and our algorithms we construct new methods of generating and pruning constraints and empirically demonstrate their usefulness.
Is Business Discourse Colonizing Philanthropy? A Critical Discourse Analysis of (PRODUCT) RED

Increasingly, traditional notions of philanthropy are colonized by a market discourse that promotes consumption as an effective way to solve social ills, resulting in what scholars have termed “marketized philanthropy.” This paper examines the implications of marketized philanthropy through a discourse analysis of the (PRODUCT) RED campaign benefiting the Global Fund to fight HIV/AIDS, malaria, and tuberculosis in Africa through consumption of (RED)-branded products. This paper explores the implications of a business-oriented model of philanthropy for bringing about social change, the repercussions of campaigns like (RED) that explicitly shed the label of philanthropy; and how they impact political engagement.
Human GABA(B) receptor 1 gene: eight novel sequence variants.

GABA (gamma-aminobutyric acid) is the principal inhibitory neurotransmitter in the brain. The human GABA(B) receptor (GABBR1) maps to the human leukocyte antigen (HLA) region of chromosome 6. Its function and location in a susceptibility region for schizophrenia, epilepsy, and dyslexia make GABBR1 a candidate gene for neurobehavioral disorders. We report the characterization of GABBR1 gene mutations in 100 chromosomes from a mixed American population. Eleven distinct mutations were found, including two previously reported missense mutations (A20V and G489S) and a previously reported silent 1977 T>C transition. Here, we report four novel silent substitutions (39C>T, 1473T>C, 1476T>C, 1545T>C) and four novel intron variants. These DNA variants may be useful in association and linkage studies of neurobehavioral disorders, and in pharmacogenetic studies of drugs targeting GABBR1.
DNA UNDER HIGH TENSION : OVERSTRETCHING, UNDERTWISTING, AND RELAXATION DYNAMICS

Single-molecule experiments indicate that a double-stranded DNA increases in length if put under tension greater than 10 pN; beyond this point its conformation can no longer be described using an inextensible wormlike-chain model. The simplest extensible wormlike chain with twist rigidity is considered as a model for DNA under tension, and it is found that the fact that DNA is chiral demands that stretching be coupled to twisting at linear order in elastic theory; stretching a DNA is thus a way to perturb its twist degress of freedom. Nonlinearities are essential to stabilize the experimentally observed ``overstretched'' state which is roughly 1.6 times the length of the unperturbed double helix, and undertwisted. If DNA linkage is held fixed, the transition to the overstretched state is strongly broadened. The overstretching model is also used to study DNA conformational change driven by the binding of RecA proteins to the double helix, and indicates that RecA cannot be dissociated from DNA by application of tension. Finally, relaxation dynamics of a stretched DNA are discussed. The existence of a dynamical writhe instability for a chain without fixed linkage number is demonstrated; it is also argued that the (undertwisted) interior of an overstretched DNA will supercoil as it relaxes.
Forecasting the frequency of changes in quoted foreign exchange prices with the autoregressive conditional duration model

Abstract This paper applies the Autorecressive Conditional Duration model to Foreign Exchange quotes arriving on Reuters screens. The Autoregressive Conditional Duration model, developed in Engle and Russell (1995) [Engle, R., Russell, J., 1995. Autoregressive conditional duration; a new model for irregularly spaced time series data, University of California, San Diego, unpublished manuscript.], is a new statistical model for the analysis of data that does not arrive in equal time intervals. When Dollar/Deutschmark data are examined, it is clear that many of the price quotes are simply noisy repeats of the previous quote. By systematically thinning the sample, a measure of the time between price changes is developed. These price durations are modeled with the ACD to obtain estimates of the instantaneous intensity of price changes. This measure is related to standard measures of volatility but is formulated in a way that incorporates the information in the irregular sampling intervals. A simple market microstructure model implies that the bid-ask spread should have predictive power for the volatility which is supported by the data. A model of price leadership however, is not supported.
Screening platelet–surface interactions using negative surface charge gradients

Abstract Negative surface charge density gradients were prepared on fused silica slides using selective oxidation of a 3-mercaptopropyltrimethoxysilane (MTS) monolayer converting surface thiol groups (–SH) into negatively charged sulfonate (−SO 3 − ) groups. The sulfonate-to-thiol gradient samples were characterized by water contact angle and electron spectroscopy for chemical analysis (ESCA). Gradients were pre-adsorbed with proteins from three different solutions: platelet free plasma (PFP), fibrinogen, or albumin in phosphate buffered saline (PBS). Washed platelets were perfused over gradient samples in a parallel plate flow chamber and platelet adhesion was measured across the gradients using differential interference contrast (DIC) microscopy. Gradients pre-adsorbed with PFP showed adhesion contrast inversely related to the negative surface charge density. The magnitude of the adhesion contrast along the gradient was also dependent on PFP concentration. Gradients pre-adsorbed with fibrinogen showed an adhesion maximum in the center of the gradient region. Albumin coating of the gradients resulted in low overall platelet adhesion with increased adhesion in regions of high negative charge density. The effect of gradient orientation with respect to the flow was also investigated. Gradients pre-adsorbed with 10% PFP showed different adhesion contrast when the platelets were perfused in opposite directions. This suggests that platelet adhesion is, in addition to responding to the local surface properties, also dependent on the upstream conditions.
An in-situ Raman spectroscopic study of the reduction of HNO3 on a rotating silver electrode

The reactivity of NO−3 at a rotating silver electrode in-situ Raman spectroscopy. It is shown that a reversible adsorption of NO−3 occurs at −0.2 V vs. SCE which can however be inhibited by nitrite in solution. The adsorption is practically rotation independent. Electrode rotation allows the distinction between vibrational peaks arising from adsorbed species and species which are diffusionally removed during the anodic dissolution of silver. Spectroscopic evidence suggesting the formation of −NHOH bonds at the electrode surface during the reduction of NO−3 is given, even when no hydroxylamine is detected in the electrolyte. A coordinated discussion of all the observed peaks at potentials between 0.4 and −0.8 V vs SCE and their dependence upon electrode rotation is also presented.
Integumentary water and sodium permeability of the yellow anaconda, Eunectes notaeus

Abstract 1. 1. The diffusion rates of Na and water between distilled water and l M NaCl were measured across shed skins of the snake Eunectes notaeus . This is a fresh-water boa that would be expected to have an integument relatively permeable to water, in comparison to terrestrial snakes. 2. 2. Instead, water influx and efflux (23 and 28 μmol/cm 2 hr respectively) were the lowest yet found for an aquatic snake. Na influx and efflux were low and similar to those of other snakes (0.16 and 0.25 μmol/cm 2 · hr respectively). There were no asymmetries or inequalities in unidirectional water or Na fluxes. 3. 3. Lipid extraction of the shed skin greatly increased the permeability to both water (about 300 fold) and Na (about 100 fold). These data are consistent with the previously postulated theory that integumentary lipids are the primary means of limiting passage of water and electrolytes. 4. 4. The very low overall water permeability of shed skins of this aquatic species is quite remarkable. Further investigation of integumentary gaseous permeability is needed to evaluate the hypothesis that there may be a link between diminished rates of water and gaseous diffusion.
Synthesis, characterisation and liquid crystalline behaviour of some lanthanides complexes containing two azobenzene Schiff base

Schiff base ligand N,N′-di-(4-butylsalicylidene)-1′,3′-diaminopropane [H2L] was synthesised by the reaction of substituted azobenzene and 1,3-diaminopropane in 2:1 molar ratio. Four mononuclear lanthanide complexes of the type [Ln(H2L)LCl] (Ln = LaIII, CeIII, SmIII and GdIII) were synthesised and characterised by 1H,13C NMR, fourier transform infrared (FT-IR) spectroscopy, elemental analysis (CHNO), gas chromotography-mass, magnetic susceptibility and molar conductivity. Thermal properties of the title compounds were studied using the thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and optical polarising microscopy (OPM). The ligand and coordination compounds exhibit liquid-crystalline properties (smectic A).
Green's function for anti-de Sitter space gravity.

We solve for the retarded Green's function for linearized gravity in a background with a negative cosmological constant, anti--de Sitter space. In this background, it is possible for a signal to reach spatial infinity in a finite time. Therefore the form of the Green's function depends on a choice of boundary condition at spatial infinity. We take as our condition that a signal which reaches infinity should be lost, not reflected back. We calculate the Green's function associated with this condition, and show that it reproduces the correct classical solution for a point mass at the origin, the anti--de Sitter--Schwarzschild solution.
The pathologic spectrum of oculoleptomeningeal amyloidosis with Val30Gly transthyretin gene mutation in a postmortem case

We report the clinical and postmortem pathologic features of a 60-year-old woman with oculoleptomeningeal amyloidosis with a Val30Gly transthyretin gene mutation. Unlike other forms of hereditary amyloidosis, this rare type displays amyloid deposition predominantly in the eyes and central nervous system. Our patient belongs to 1 of only 2 kindreds known to carry this transthyretin mutation. Previous reports focused on examination of the brain and spinal cord, largely ignoring postmortem examination of the eyes. In this case, autopsy examination revealed amyloid deposition in the leptomeninges surrounding the brain, spinal cord, and optic nerves. Subependymal amyloid deposits projecting into the lateral ventricles as well as amyloid deposition in the choroid plexus, retinal vessels, nerve fiber layer of the retina, and vitreous were observed. Amyloid was not identified elsewhere in the body. Awareness of this rare form of hereditary amyloidosis is crucial, given the substantial genetic and therapeutic implications of the diagnosis. Oculoleptomeningeal amyloidosis can be easily diagnosed during life with vitreous biopsy, as was the case in our patient.
A study of uniform isothermal processing of nuclear emulsions

Nuclear emulsions exposed to the 1.86 GeV/o positive particle beam at the Berkeley Bevatron were developed using a variety of methods. It was found that an isothermal procedure at 10 °C could give satisfactory uniformity of development with depth. Data are also presented on the grain size, background grain density and distortion for the different methods used.
The effects of active versus reflective learning style on the processes of critical discourse in computer‐supported collaborative argumentation

This study examined how message-response exchanges produced in the interactions between active learners only, reflective learners only, active-reflective learners and reflective-active learners affected how often active versus reflective learners posted rebuttals to arguments and challenges across four types of exchanges that believed to promote critical discourse (argument–challenge, challenge–counterchallenge, challenge–explain, challenge–evidence) in computer-supported collaborative argumentation (CSCA). This study found that the exchanges between reflective learners produced 44% more responses than in the exchanges between active learners ( ES = +0.17). The reflective–reflective exchanges produced 47% more responses than the active–reflective exchanges ( ES = +0.18). These results suggest that groups with reflective learners only are likely to produce more critical discourse than groups with active learners only, and the ratio of active–reflective learners within a group can potentially influence overall group performance. These findings illustrate how specific traits of the learner can affect discourse processes in CSCA and provide insights into process-oriented strategies and tools for structuring dialogue and promoting critical inquiry in online discussions.
Innovation as a structural interest: rethinking the impact of network position on innovation adoption

Abstract The act of adopting an innovation is argued to be a type of structural interest. The proposed conception of innovation as a structural interest describes how a potential adopter perceives utility in innovating as a function of his position in network(s) of relations with other potential adopters. Implications of the concept are in accord with diffusion research describing the linkage between social structure and innovation in terms of a potential adopter's social integration. The proposed concept avoids, however, three ambiguities in translating social integration into a structural concept stated in terms of network position. Moreover, it extends the scope of earlier work to suggest new connections between social structure and innovation. In order to make empirical implications explicit, hypotheses for a reanalysis of the classic Medical Innovation data are described. The proposed conception of innovation states the utility a doctor should perceive in prescribing a new drug as a function of his position in professional and social networks among other doctors in his community. The hypotheses predict when a doctor should begin prescribing a new drug and the relative importance of his personal characteristics versus network position as the determinant of when he begins prescribing the new drug.
HIV and HCV Coinfection: Where Are We in 2010?

The epidemics of hepatitis C virus (HCV) and HIV are major causes of morbidity and mortality worldwide; the 33 million individuals who are coinfected with HCV and HIV face an increased risk of complications and death from liver disease in light of the accelerated progression of hepatitis C to fibrosis and cirrhosis in HIV coinfection. The mechanisms by which HIV accelerates the progression of HCV are thought to be related to alterations in the immunologic milieu, which collectively act to promote fibrogenesis. The progression of liver disease is in large part related to immunodeficiency, and, as with monoinfected individuals, optimal management of HIV infection with HAART may be important for prevention of hepatic morbidity. Treatment of HCV with pegylated interferon and ribavirin should be considered in eligible coinfected persons. Clinical trials in this population demonstrate sustained virologic response rates ranging from 17% to 35% in genotypes 1 and 4 and 44% to 73% in genotypes 2 and 3. However, given these limited response rates and high rates of intolerability, the impending introduction of directly acting antivirals against HCV holds particular promise for interruption of the insidious natural history of liver disease in HIV coinfected persons.
Steroid 17,20-lyase: the effect of detergents on enzymic activity and microsomal composition.

Abstract The activity of the steroid 17, 20-lyase from rat testis microsomes was determined following exposure of the microsomes to detergents. Only Triton N-101 and X-100 produced enzymically active supernatants. The supernatant from Triton N-101 treatment consisted of submicrosomal particles enriched in cytochrome P450, flavin, and phospholipid; depleted in RNA and NADPH oxidase; and unchanged in the concentration of cytochrome b 5 and non-heme iron. The activities of the NADPH and NADH cytochrome C reductases were also intact. Lubrol produced an inactive supernatant which contained all the components thought to be necessary for microsomal electron transport with the exception of cytochrome b 5 . An assay, specific for cleavage and more expeditious than the chromatographic separation of reactants, is also described.
Gender markedness: the anatomy of a counter-example

The morphological expression of gender on nouns displays a puzzling behaviour under ellipsis of nominal predicates. In some instances, it appears that gender can be ignored in the calculation of the identity/parallelism requirement. With other nouns, gender seems relevant and mismatch engenders parallelism violations. With yet a third group of nouns, there is an asymmetry—an overt masculine noun licenses ellipsis of the corresponding feminine, but not vice versa. The difference between the last two groups is exemplified by the English contrast in: John is a {waiter/#prince} and Mary is too (compare #Mary is a waitress/princess, and John is too). We examine six languages, and show that nouns for nobility/titles and kinship nouns form a systematic exception to an otherwise stable marked: unmarked opposition, and that when this class of nouns is factored out, the remaining two classes reflect the inflection/derivation distinction in the morphological realization of gender.
Effect of animal browse protection and fertilizer application on the establishment of planted Nuttall oak seedlings

For establishment to be successful, planted oak must emerge above vegetative competition and browse level. A 3 year study was established in 2000 in a cutover bottomland hardwood forest in west Alabama to examine the influences of seedling browse protection and fertilizer use on growth of Nuttall oak (Quercus nuttallii Palm.) seedlings. The treatments included: control, 1.2 m tall wire tree shelter, and 1.2 m tall plastic tree shelter. Fertilizer (20–10–5) was applied to one-half of all seedlings at planting. Competing vegetation was controlled around all seedlings with mulch mats and herbicide. Fertilization did not affect height growth or successful establishment after 3 years. Four percent of protected seedlings (plastic and wire tree shelters combined) were browsed compared to 95% of control seedlings. After 3 years, plastic tree shelters were the most effective treatment for promoting height growth and successful seedling establishment of Nuttal oak seedlings (193 cm, 92.71% compared to 120 cm, 68.75% and 52 cm, 8.33% for wire tree shelter, and control seedlings, respectively). Animal browse protection is deemed essential for successful seedling establishment in southern bottomland forests where deer density is high (density estimated at 27 km−2 in vicinity of study area).
Effects of wall distensibility on the numerical simulation of arteriovenous fistulae

Arteriovenous fistulae are created surgically to provide an adequate access for dialysis in patients with End-Stage Renal Disease (ESRD). Producing an autogenous shunt linking an artery and a vein in the peripheral circulation bypasses the high resistance capillary bed in order to provide the necessary flow rates at sites easily accessible for dialysis. It has long been recognized that hemodynamics constitute the primary external influence on the remodeling process of anastomosed vascular tissue [1, 2]. The high flow rate, together with the exposure of the venous tissue to the high arterial pressure, leads to a rapid process of wall remodeling that may lead to a mature access or end in failure. Recent hemodynamic simulations [3, 4] have computed very high viscous wall shear stresses within dialysis access fistulae; Stresses >15 Pa have been reported. These are much higher than what is typically considered normal or homeostatic (i.e. ≈ 1–1.5 Pa). The abnormal stresses in the fistulae have been hypothesized to cause pathological venous remodeling (i.e. intimal hyperplasia) which causes stenoses and threatens fistula patency. Given the high failure rate of dialysis access sites (up to 50% require surgical revision within one year), understanding the dynamics of blood flow within the fistula is a necessary step in understanding remodeling, and ultimately, in improving clinical outcomes.© 2013 ASME
Evaluation of Harmonic Coupling Weights in Nonlinear Periodicity Preservation Systems

When stimulated by a periodic stimulus, every component of a possibly nonlinear periodicity preservation system oscillates periodically with the same period as the stimulus. Changes in the harmonic structure of the the stimulus couples each input harmonic to, in general, every response harmonic. Knowledge of harmonic coupling weights (HCWs) allows model free characterization of effects of all small stimulus perturbation. This paper develops foundational methodology for experimentally measuring the HCWs. The on-frequency method uses small tickle tones at harmonic frequencies to do this. The off-frequency method places tickle tones adjacent to harmonic frequencies and is applicable to PP systems that are locally frequency invariant. Memoryless nonlinear PP systems are an example where the approach works exactly. The off-frequency method also requires fewer experiments. In some cases, the off-frequency method can be extended to measure numerous HCWs in a single experiment. Some system types such as the memoryless nonlinearity, require fewer experiments than general PP systems. Methods to experimentally measure the Hessian are also presented.
Continuum modeling of localized deformation in irradiated bcc materials

Abstract A continuum constitutive crystal plasticity framework is implemented to model the post-irradiation tensile behavior of bcc structural materials, accounting for localized deformation due to the formation of dislocation channels. Both the mechanical response and deformed microstructure of the material are modeled for quasi-static tensile loading. The latter is studied to identify the stages of dislocation channel formation during localization, specifically with respect to the evolution of dislocations and irradiation-induced defects. Parametric studies of the cross-slip and flow softening (due to annihilation of irradiation-induced defects) models are performed to study their effects on the localization behavior. Results are compared to available experimental data.
In vitro test of the cytotoxic equivalence between pulsed dose rate and continuous low dose rate

Pulsed low dose rate (PDR) irradiation is being investigated as an alternative to continuous low dose rate (CLDR) irradiation for the treatment of certain malignancies. Mathematical modeling by Brenner and Hall suggests that the two irradiation regimens will be equivalent under certain conditions. We are testing these predictions directly by using the mouse/SCC VII in vitro-in vivo tumor model. This study involved in vitro irradiations that would not be expected to severely stress the assumptions of the mathematical model. The cytotoxicity of CLDR was compared to that for PDR regimens consisting of hourly radiation pulses of 5, 10, or 20 minutes and a 20-minute radiation pulse every 2 hours. A total dose of 15.7 Gy of 60Co γ-rays was delivered over the same total time for all irradiations. Confluent cultures were irradiated in low serum at room temperature to minimize the effects of cell proliferation and cell cycling. Flow cytometric analysis demonstrated that an average of ≧80% of cells were in G0/G1 phase, with ≦5% incorporating bromodeoxyuridine. Also, mitotic indices averaged <0.2%. There were no significant differences between the mean values for these cell cycle measures between CLDR and PDR or between PDR regimens. All PDR regimens showed increased cell kill relative to the CLDR, but in no case were the increases statistically significant. The increase in cell kill was by factors of 1.14–2.00, with the greatest increase in cell kill in the PDR regimen using 5-minute pulses once per hour. The increase in cell kill, even if it was real, would not appear to be sufficient to violate the criteria for being “clinically indistinguishable,” as suggested by Brenner and Hall. Although these results generally support the modeling of Brenner and Hall, this experimental model does show increased cell killing in the PDR regimens, and this in vitro model does not stress the assumptions of the Brenner-Hall model as severely as in vivo models would. © 1995 Wiley-Liss, Inc.
Towards a theory of the labor market with a public sector

Abstract The object is to specify and analyze equilibrium in a labor market with frictions when there is a significant public sector. In the vast majority of equilibrium studies on labor markets, a public sector has been ruled out by assumption. This seems a strange oversight as about 17% of workers in the US are public sector workers, whereas in western Europe, approximately 22% of workers work in the public sector. The goal in this study is to provide answers to such questions as: what happens to private sector wages if the public sector is increased? If the Government increases the number of public sector jobs, does this crowd out private sector jobs? When will private sector wages be greater (less) than the public sector wage? Reasonably complete answers to these questions (and others) are provided within the context of the model developed.
Activation of phospholipase C-gamma by phosphatidylinositol 3,4,5-trisphosphate.

Signal transduction across cell membranes often involves the activation of both phosphatidylinositol (PI)-specific phospholipase C (PLC) and phosphoinositide 3-kinase (PI 3-kinase). Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a substrate for both enzymes, is converted to phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) by the action of PI 3-kinase. Here, we show that PI(3,4,5)P3 activates purified PLC-γ isozymes by interacting with their Src homology 2 domains. Furthermore, the expression of an activated catalytic subunit of PI 3-kinase in COS-7 cells resulted in an increase in inositol phosphate formation, whereas platelet-derived growth factor-induced PLC activation in NIH 3T3 cells was markedly inhibited by the specific PI 3-kinase inhibitor LY294002. These results suggest that receptors coupled to PI 3-kinase may activate PLC-γ isozymes indirectly, in the absence of PLC-γ tyrosine phosphorylation, through the generation of PI(3,4,5)P3.
Relationships Among Measures of Perceived Self-Efficacy With Respect to Basic Domains of Vocational Activity

This study provides evidence concerning the construct validity of the Task-Specific Self-Efficacy Scale (TSOSS) and the Skills Confidence Inventory (SCI), both measures of self-efficacy with respect to basic domains of vocational behavior. Relationships between similarly named scales, that is, TSOSS-Verbal/interpersonal with SCI-Social, TSOSS-Quantitative with SCI-Investigative, TSOSS- Physical with SCI-Realistic, and TSOSS-Aesthetic with SCI-Artistic, were high, ranging from r = .50 to .80. Negligible relationships of self- efficacy to measured ability and significant relationships of self- efficacy with respect to Verbal/interpersonal and Social dimensions to career indecision were also reported and discussed.
Constitutive systemic expression of IL-1Ra or soluble TNF receptor by genetically modified hematopoietic cells suppresses LPS induction of IL-6 and IL-10.

We have been developing both local and systemic gene therapy approaches to treat inflammatory and autoimmune diseases. To determine if systemic, constitutive expression of biologically active anti-inflammatory agents is therapeutic and/or has associated toxicity, mouse hematopoietic stem cells were infected with retroviral vectors carrying the genes for human IL-1 receptor antagonist (IL-1Ra), human soluble TNF receptor p75 (sTNFR), or the β-galactosidase (lacZ) gene, and transplanted into lethally irradiated recipients. The serum levels of human IL-1Ra and human sTNFR in the long-term reconstituted mice, 2–7 months after transplantation, were 596 and 158 ng/ml respectively. The long-term expression of human IL-1Ra had minimal effects on the PBMC profile whereas human sTNFR expression increased the percentage of B220 and Mac.1 stained cells and decreased slightly the specific T cell subsets. The ability of these proteins to protect the transplanted mice from endotoxin treatment was determined by measuring serum interleukin-6 (IL-6) and interleukin-10 (IL-10) responses after LPS injection at 1.5, 3, 4.5 and 24 h after treatment. The IL-1Ra group showed diminished IL-10 levels and less mortality after injection of LPS compared to the lacZ controls. Mice expressing sTNFR had lower IL-10 and IL-6 levels following injection of LPS. These results demonstrate that constitutive, systemic expression of IL-1Ra and sTNFR is able to confer partial protective effects following treatment with endotoxin. These results further demonstrate that gene transfer methods which result in systemic, long-term expression of immunodulatory proteins could be applied to the treatment of inflammatory diseases.
Updates on Endoscopic Laryngeal Imaging

In this paper, I will provide an update on work published in the past 2 years on endoscopic laryngeal imaging techniques including stroboscopy, high-speed digital imaging, and videokymography. There is increasing evidence in the literature from the past 2 years on the clinical usefulness of high-speed digital imaging and kymography as an adjunct to stroboscopy to understand the pathophysiology of hoarseness. The evidence is particularly strong in cases with moderate-to-severe aperiodicity. Recent evidence suggests that these endoscopic imaging techniques (with increased spatial resolution of up to 8,000 frames per second) have potential for objectively characterizing normal and disordered vibratory motion in adults and children. High-speed digital imaging and kymography have the potential to provide quantitative and visual-perceptual measurements of vibratory function that researchers can use to improve the assessment and treatment of voice disorders in children and adults.
P2P Reputation Management Using Distributed Identities and Decentralized Recommendation Chains

Peer-to-peer (P2P) networks are vulnerable to peers who cheat, propagate malicious code, leech on the network, or simply do not cooperate. The traditional security techniques developed for the centralized distributed systems like client-server networks are insufficient for P2P networks by the virtue of their centralized nature. The absence of a central authority in a P2P network poses unique challenges for reputation management in the network. These challenges include identity management of the peers, secure reputation data management, Sybil attacks, and above all, availability of reputation data. In this paper, we present a cryptographic protocol for ensuring secure and timely availability of the reputation data of a peer to other peers at extremely low costs. The past behavior of the peer is encapsulated in its digital reputation, and is subsequently used to predict its future actions. As a result, a peer's reputation motivates it to cooperate and desist from malicious activities. The cryptographic protocol is coupled with self-certification and cryptographic mechanisms for identity management and countering Sybil attack. We illustrate the security and the efficiency of the system analytically and by means of simulations in a completely decentralized Gnutella-like P2P network.
What Happens to the Optic Disc and Retina in Glaucoma

Abstract In glaucoma, there is a spectrum of disc damage ranging from highly localized tissue loss (a notch in the neuroretinal rim), vertically oval cupping, or simple concentric enlargement of the cup. The accompanying visual loss may likewise range from a well-localized nerve fiber bundle defect to a generalized depression. Cases with diffuse loss of axons, a concentric enlargement of the cup, and a generalized reduction in visual function are more difficult to recognize unless the previous state of the disc and vision is well documented or there is asymmetry between the two eyes.
Energy inefficiency in industrial agriculture: You are what you eat

Modern industrial farming technologies have changed substantially in recent decades. In many locations such as Arizona, these industries are highly energy and water-intensive operations. The sustainability of these operations is called into question. The economic, social and climate implications of energy use in agriculture are worth further discussion. Based on the idea of a sustainable energy budget, the production processes of various foods are analyzed which prove to be very energy inefficient. The environmental, ecological and social justice issues of modern industrial agriculture require a reassessment form myriad perspectives: farm subsidies, consumer demand and preferences, engineering technologies, and water policy.
Achieving minimum length scale in topology optimization using nodal design variables and projection functions

A methodology for imposing a minimum length scale on structural members in discretized topology optimization problems is described. Nodal variables are implemented as the design variables and are projected onto element space to determine the element volume fractions that traditionally define topology. The projection is made via mesh independent functions that are based upon the minimum length scale. A simple linear projection scheme and a non-linear scheme using a regularized Heaviside step function to achieve nearly 0–1 solutions are examined. The new approach is demonstrated on the minimum compliance problem and the popular SIMP method is used to penalize the stiffness of intermediate volume fraction elements. Solutions are shown to meet user-defined length scale criterion without additional constraints, penalty functions or sensitivity filters. No instances of mesh dependence or checkerboard patterns have been observed. Copyright © 2004 John Wiley & Sons, Ltd.
Analysis of a soft-switching technique for isolated time-sharing multiple-input converters

This paper explores the feasibility of active clamping techniques in isolated time-sharing multiple-input converters. Additional losses caused by energy transfer into the input switches from the leakage inductance in the isolating coupled-inductor are addressed with a common active clamping leg for all input legs. An active clamping technique is applied to isolated time-sharing multiple-input converters to minimize the additional switching losses, and the paper also conducts an operational analysis of a dual-input isolated single ended primary inductor converter (2IISEPIC) with the active clamping technique. Zero-voltage-switching can be achieved on the first-turned-on input leg and the active clamping leg with proper driving strategy and circuit parameter settings. Discussions on the effect of the active clamping technique to a multiple-input converter and the components stresses of the 2IISEPIC with the active clamping technique have also been made to assist in the design of time-sharing multiple-input converters. A prototype of the 2IISEPIC with the active clamping technique is built for efficiency and stresses verification, and it is showed that 94% efficiency is achievable at 200W output power and the component stresses are significantly reduced, especially the voltage stresses on input switches. An absolute 6 % improvement over the efficiency of the same circuit without soft-switching techniques is observed.
Solution structure of the Rous sarcoma virus nucleocapsid protein: muPsi RNA packaging signal complex.

Abstract The 5′-untranslated region (5′-UTR) of retroviral genomes contains elements required for genome packaging during virus assembly. For many retroviruses, the packaging elements reside in non-contiguous segments that span most or all of the 5′-UTR. The Rous sarcoma virus (RSV) is an exception, in that its genome can be packaged efficiently by a relatively short, 82 nt segment of the 5′-UTR called μΨ. The RSV 5′-UTR also contains three translational start codons (AUG-1, AUG-2 and AUG-3) that have been controvertibly implicated in translation initiation and genome packaging, one of which (AUG-3) resides within the μΨ sequence. We demonstrated recently that μΨ is capable of binding to the cognate RSV nucleocapsid protein (NC) with high affinity (dissociation constant K d ∼ 2 nM), and that residues of AUG-3 are essential for tight binding. We now report the solution structure of the NC:μΨ complex, determined using NMR data obtained for samples containing ( 13 C, 15 N)-labeled NC and 2 H-enriched, nucleotide-specifically protonated RNAs. Upon NC binding, μΨ adopts a stable secondary structure that consists of three stem loops (SL-A, SL-B and SL-C) and an 8 bp stem (O3). Binding is mediated by the two zinc knuckle domains of NC. The N-terminal knuckle interacts with a conserved U(217)GCG tetraloop (a member of the UNCG family; N = A,U,G or C), and the C-terminal zinc knuckle binds to residues that flank SL-A, including residues of AUG-3. Mutations of critical nucleotides in these sequences compromise or abolish viral infectivity. Our studies reveal novel structural features important for NC:RNA binding, and support the hypothesis that AUG-3 is conserved for genome packaging rather than translational control.