cssi/SciSciGPT-SciSciNet huggingface dataset:
Treatment of dissecting pseudoaneurysm of the cervical internal carotid artery using a wall stent and detachable coils: case report.

OBJECTIVE AND IMPORTANCE:This case illustrates the use of an endovascular stent and coiling combination to treat a giant wide-necked pseudoaneurysm of the cervical internal carotid artery.CLINICAL PRESENTATION:A 20-year-old male patient presented with a bilateral dissection of the cervical internal
Total Synthesis of (-)-Bafilomycin A1: Application of Diastereoselective Crotylboration and Methyl Ketone Aldol Reactions

A careful orchestration of protecting groups is an essential requirement for the total synthesis of the macrolide antibiotic bafilomycin A1 (1). Key steps were the Suzuki cross-coupling reaction of two advanced, suitably protected intermediates prior to closure of the macrocycle, as well as a highly stereoselective methyl ketone aldol reaction.
The vectorcardiographic significance of upright T waves in V1 and V2 during the first months of life

Even though positive T waves in the right chest leads of infants have been considered mainly to be due to right ventricular enlargement, there are still other causes which can produce similar changes. The spatial vectorcardiographic significance of such conditions has been studied in normal as well as in abnormal hearts. The morphology, rotation, and orientation of the T loop has been analyzed during the immediate neonatal period; in right, left, and biventricular enlargements, as well as in malnourished children with diarrhea. The differential diagnosis between the various abnormalities is stressed, based mainly in the changes in the repolarization complex.
The Effect of Thermal Expansion on Spallation Behavior of Fe-Base Alumina-Forming Alloys

Long-term cyclic oxidation behavior was compared for commercial FeCrAl alloys and model Fe-Al and FeCrAl alloys, and their coefficients of thermal expansion (CTE) were measured. For single-phase disordered (ferritic) Fe(Al) alloys, the CTE increased only slightly with Al content and was similar to that of FeCrAl alloys. More significant CTE increases were observed at ≥20%Al, as intermetallic phases, Fe3Al and FeAl, formed. As expected, the intermetallic compositions showed increased oxide spallation rates during cyclic oxidation at 1100° and 1200°C. However, after extensive spallation and loss of Al from the substrate, the compositions of Fe3Al and FeAl specimens entered the ferritic phase field, and the amount of scale spallation decreased. Among commercial oxide dispersion strengthened (ODS) FeCrAl alloys, a composition containing Mo (ODM751) exhibited the lowest thermal expansion and showed the slowest degradation rate in long-term testing at 1100°C. The concept of minimizing CTE as a route for alloy development was investigated.
Applications of MoSi-based binary intensity mask for sub-40nm DRAM

In this paper, we will present applications of MoSi-based binary intensity mask for sub-40nm DRAM with hyper-NA immersion scanner which has been the main stream of DRAM lithography. Some technical issues will be reported for polarized illumination and mask materials in hyper-NA imaging. One att.PSM (Phase Shift Mask) and three types of binary intensity mask are used for this experiment; those are ArF att.PSM ( MoSi:760A , transmittance 6% ), conventional Cr ( 1030A ) BIM (Binary Intensity Mask), MoSi-based BIM ( MoSi:590A , transmittance 0.1%) and multi layer ( Cr:740A / MoSi:930A ) BIM. Simulation and experiment with 1.35NA immersion scanner are performed to study influence of mask structure, process margin and effect of polarization. Two types of DRAM cell patterns are studied; one is a line and space pattern and the other is a contact hole pattern through mask structure. Various line and space pattern is also through 38nm to 50nm half pitch studied for this experiment. Lithography simulation is done by in-house tool based on diffused aerial image model. EM-SUITE is also used in order to study the influence of mask structure and polarization effect through rigorous EMF simulation. Transmission and polarization effects of zero and the first diffraction orders are simulated for both att.PSM and BIM. First and zero diffraction order polarization are shown to be influenced by the structure of masking film. As pattern size on mask decreases to the level of exposure wavelength, incident light will interact with mask pattern, thereby transmittance changes for mask structure. Optimum mask bias is one of the important factors for lithographic performance. In the case of att.PSM, negative bias shows higher image contrast than positive one, but in the case of binary intensity mask, positive bias shows better performance than negative one. This is caused by balance of amplitude between first diffraction order and zero diffraction order light.1 Process windows and mask error enhancement factors are measured with respect to several types of mask structure. In the case of one dimensional line and space pattern, MoSi-based BIM and conventional Cr BIM show the best performance through various pitches. But in the case of hole DRAM cell pattern, it is difficult to find out the advantage of BIM except of exposure energy difference. Finally, it was observed that MoSi-based binary intensity mask for sub- 40nm DRAM has advantage for one dimensional line and space pattern.
The potential for nanostructured materials in gas turbine engines

Abstract There is a continuing need for gas turbine engines with improved durability and performance. Of all the technologies contributing to future gas turbines, advanced materials, such as nanostructured materials, are expected to provide more than 5096 of the required improvements. Nanostructured materials are required with improved strength, toughness and temperature cgpabditks. The enhanced plasticity and dfusivity of nanostructured materials can also serve to facilitate the fabrication of complex materials and structures. This paper describes a procedure for the aggressive research and development of nanostructured materials.
A new randomized response device for sensitive characteristics: an application of the negative hypergeometic distribution

In this paper, a new randomized response device is proposed based on the use of negative hypergeometric distribution while estimating the proportion of persons possessing a sensitive characteristic in a population. Situations where the proposed randomization device can perform better than the Warner (J Am Stat Assoc 60, 63–69, 1965), the Kuk (Biomerika 77(2), 436–438, 1990) and the Mangat (J R Statist Soc B 56, 93–95, 1994) estimators are simulated and discussed.
Selecting a sample size for studies with repeated measures

Many researchers favor repeated measures designs because they allow the detection of within-person change over time and typically have higher statistical power than cross-sectional designs. However, the plethora of inputs needed for repeated measures designs can make sample size selection, a critical step in designing a successful study, difficult. Using a dental pain study as a driving example, we provide guidance for selecting an appropriate sample size for testing a time by treatment interaction for studies with repeated measures. We describe how to (1) gather the required inputs for the sample size calculation, (2) choose appropriate software to perform the calculation, and (3) address practical considerations such as missing data, multiple aims, and continuous covariates.
Jewish immigrant skill and occupational attainment at the turn of the century

Abstract The 1900 Census of Population microdata file is used to study the occupational status of adult male Jewish immigrants in comparison with other immigrants and native-born white men. On arrival the Jewish immigrants had a low occupational status but they experienced very rapid improvements with duration. Occupational parity was reached with Western European and Canadian immigrants (5 1 2 years after immigration) and the native born (14 years). The Jewish adjustment pattern followed the model of refugees. Their high level of attainment reflected large human capital investments (at home and in school) and an emphasis on decision making skills.
Speed Function Effects in Electron Beam Additive Manufacturing

In this paper, the process parameter effects on the thermal characteristics in powder-bed electron beam additive manufacturing (EBAM) using Ti-6Al-4V powder were investigated. The machine-specific setting, called “speed function” (SF) index that controls the beam speed and the beam current during a build, was utilized to evaluate the beam scanning speed effects. EBAM parts were fabricated using different levels of SF index (20 to 65) and build surface morphology and part microstructures were examined. A near infrared (NIR) thermal imager was used for temperatures measurements during the EBAM process. In addition, a thermal model previously developed was employed for temperature predictions and comparison with the experimental results.The major results are summarized as follows. The SF index noticeably affects the thermal characteristics in EBAM, e.g., a melt pool length of 1.72 mm vs. 1.26 mm for SF20 and SF65, respectively, at the 24.43 mm build height. This is because the higher the speed function index, the higher the beam speed, which reduces the energy density input and results in a lower process temperature. For the surface conditions and part microstructures, in general, a higher SF index tends to produce parts of rougher surfaces with more residual porosity features and large β grain columnar widths.Copyright © 2014 by ASME
Temporal relations between methamphetamine use and HIV seroconversion in gay, bisexual, and other men who have sex with men

Data from a cross-sectional study of gay, bisexual, and other men who have sex with men who were active methamphetamine users were analyzed to assess temporal relations between HIV seroconversion and initiation of methamphetamine use. Of the 100 men, 58 reported being HIV-positive. Most HIV-positive participants (65%) initiated methamphetamine use after seroconverting. Among those who initiated use before seroconversion, 8 years elapsed between onset of use and time of infection. Findings suggest the need to develop nuanced and targeted interventions aimed at disentangling the “meth-sex” link in this population. Findings also suggest use of the drug as a coping mechanism for those living with HIV.
Comparison of urinary phosphate, urate and magnesium excretion following parathyroid hormone administration to normal man

Abstract A phosphaturic dose of parathyroid hormone (PTH) administered intravenously to 14 normal volunteers significantly decreased magnesium excretion and did not significantly alter urate excretion. Elevated plasma levels of endogenous PTH appear to mediate the increased excretion of phosphate per nephron observed in progressive chronic renal disease. In this setting, a similar pattern of urate and magnesium excretion is seen. Results of this study fail to support the concept that PTH might play a role in the enhanced urate and magnesium excretion per nephron of subjects with chronic renal failure.
Copper-Catalyzed Asymmetric N−H Insertion Reactions: Couplings of Diazo Compounds with Carbamates to Generate α-Amino Acids

A Cu/chiral bipyridine catalyst has been developed for the asymmetric insertion of α-diazocarbonyl compounds into the N−H bonds of carbamates to generate an array of easily deprotected arylglycines in good ee. With respect to the reaction partners, as well as the ligand, this process complements the only other report of highly enantioselective N−H insertion reactions.
Substrate specificity and identification of functional groups of homoserine kinase from Escherichia coli

Homoserine kinase, an enzyme in the aspartate pathway of amino acid biosynthesis in Escherichia coli, catalyzes the conversion of L-homoserine to L-homoserine phosphate. This enzyme has been found to have broad substrate specificity, including the phosphorylation of L-homoserine analogs where the carboxyl functional group at the alpha-position has been replaced by an ester or by a hydroxymethyl group. Previous pH profile studies [Huo. X., & Viola, R. E. (1996) Arch. Biochem. Biophys. 330, 373-379] and chemical modification studies have suggested the involvement of histidinyl, lysyl, and argininyl residues in the catalytic activity of the enzyme. With the assistance of sequence alignments, several potential amino acids have been targeted for examination. Site-directed mutagenesis studies have confirmed a role for arginine-234 in the binding of the carboxyl group of L-homoserine, and the involvement of two histidine at the homoserine binding site. Mutations at these sites have led to the decoupling of the kinase activity from an inherent ATPase activity in the enzyme, and suggest the presence of independent domains for the binding of each substrate in homoserine kinase.
Assessing health system performance in developing countries: A review of the literature

With the setting of ambitious international health goals and an influx of additional development assistance for health, there is growing interest in assessing the performance of health systems in developing countries. This paper proposes a framework for the assessment of health system performance and reviews the literature on indicators currently in use to measure performance using online medical and public health databases. This was complemented by a review of relevant books and reports in the grey literature. The indicators were organized into three categories: effectiveness, equity, and efficiency. Measures of health system effectiveness were improvement in health status, access to and quality of care and, increasingly, patient satisfaction. Measures of equity included access and quality of care for disadvantaged groups together with fair financing, risk protection and accountability. Measures of efficiency were appropriate levels of funding, the cost-effectiveness of interventions, and effective administration. This framework and review of indicators may be helpful to health policy makers interested in assessing the effects of different policies, expenditures, and organizational structures on health outputs and outcomes in developing countries.
Lyapunov-stable adaptive stabilization of non-linear time-varying systems with matched uncertainty

This paper considers direct adaptive stabilization of multi-input non-linear time-varying systems with full-state feedback and state-and-time-dependent uncertainty. The novel result of this paper is a single-parameter adaptive controller that yields a Lyapunov-stable closed-loop system. We demonstrate the controller on a non-linear spring-mass-damper, a three-degree-of-freedom Mathieu equation, and a 4th-order non-linear time-varying system.
Theory of Diamagnetic Susceptibility of Metals

In order to calculate the diamagnetic susceptibility of real metals, we have generalized the pseudopotential method to the case of a metal in a magnetic field. A general equation of motion is obtained, from which we first derive an expression for the core diamagnetism. We then derive an expression for the diamagnetic susceptibility of Bloch electrons in a magnetic field in terms of a pseudopotential. If our pseudopotential is replaced by the actual lattice potential, the result reduces exactly to expressions derived by other authors for the diamagnetic susceptibility of Bloch electrons. However, we believe that our method is the simplest manner in which this result can be derived. By the use of the pseudopotential and degenerate perturbation theory we obtain the result in a form from which computation can be made easily. We have computed the diamagnetic susceptibility of all the alkali metals and of aluminum. From our expression, the diamagnetic susceptibility of any polyvalent metal to which our approximations apply can be easily computed. We have also found a satisfactory explanation of why certain metals have very high diamagnetic susceptibility. We contradict Glasser's conclusion that the diamagnetic susceptibility and the paramagnetic susceptibility are nonadditive, and correct some algebraic errors in the work of Samoilovich and Rabinovich.
Breach erosion of earthfill dams (BEED) model

A computer model has been developed for simulation of breach erosion of earthfill dams (BEED). The model incorporates the processes of surface erosion and slope sloughing to simulate breach enlargement. Depletion of reservoir water is approximated by a volume continuity equation while broad-crested weir hydraulics is utilized to describe flow over and through the breach. Due to the implicit form of these equations, an iterative solution is proposed with convergence achieved within only a few iterations. The BEED model is written in both FORTRAN 77 and BASIC computer languages. Testing of the model using historical data of the failures of Teton and Huaccoto dams showed that timing, shape, and magnitude of the predicted outflow hydrograph were adequately simulated by this model. The same is true for the dimensions of the terminal breach. A sensitivity analysis indicated that internal friction angle and the relation for surface erosion were the major factors affecting the model results.
Helicobacter pylori culture and antimicrobial susceptibility from pediatric patients in Michigan.

Background. We recently observed a high failure rate in the eradication of Helicobacter pylori infection in children with 2-week triple therapy using lansoprazole, amoxicillin and clarithromycin. We performed a prospective evaluation of antral biopsies of all children subsequently diagnosed with H. pylori gastritis for culture and antimicrobial susceptibility assessment. Methods. All children with antral nodularity and/or an elevated anti-H. pylori IgG titer underwent antral biopsies for histology, urease test and culture while undergoing an upper endoscopy for routine indications. All positive cultures were tested for antimicrobial susceptibility by E-test for clarithromycin, amoxicillin, tetracycline and metronidazole. Results. Thirty-one children (16 male, 15 female) between 2 and 19 years of age were diagnosed with H. pylori gastritis by histology. However, culture was positive in only 22 of 31 (71%) patients. The E-test in vitro antimicrobial susceptibility testing revealed that 95.6% of the isolates were susceptible to amoxicillin, 59% to clarithromycin and 54.6% to metronidazole. There was no resistance to tetracycline. Conclusion. Evaluation of antibiotic resistance profiles from pediatric patients from different geographic areas can help in optimizing therapeutic regimen to prevent treatment failures. Metronidazole and clarithromycin resistance is much higher in our pediatric population than reported in adults and could be a major contributor to failure of H. pylori eradication.
CdZnTe background measurements at balloon altitudes with PoRTIA

Measurements of the CdZnTe internal background at balloon altitudes are essential to determine which physical processes make the most important background contributions. We present results from CdZnTe background measurements made by PoRTIA, a small CdZnTe balloon instrument that was flown three times in three different shielding configurations. PoRTIA was passively shielded during its first flight from Palestine, Texas and actively shielded as a piggyback instrument on the GRIS balloon experiment during its second and third flights from Alice Springs, Australia, using the thick GRIS Nal anticoincidence shield. A significant CdZnTe background reduction was achieved during the third flight with PoRTIA placed completely inside the GRIS shield and blocking crystal, and thus completely surrounded by 15 cm of Nal. A unique balloon altitude background data set is provided by CdZnTe and Ge detectors simultaneously surrounded by the same thick anticoincidence shield; the presence of a single coxial Ge detector inside the shield next to PoRTIA allowed a measurement of the ambient neutron flux inside the shield throughout the flight. These neutrons interact with the detector material to produce isomeric states of the Cd, Zn and Te nuclei that radiatively decay; calculations are presented that indicate that these decays may explain most of the fully shielded CdZnTe background.
An infrared study of polyhydroxymethylene and deuterated polyhydroxymethylene

The polarized infrared spectra of oriented polyhydroxymethylene films were determined in the range 5000–500 cm.−1. The films then were deuterated and the spectra again recorded. A tentative assignment of the major abosrption bands is proposed on the basis of a simple zigzag chain model with a 2.5 A. repeat distance. The rate of hydrogen–deuterium exchange of a film with atmospheric water vapor was measured and found to be diffusion-controlled.
Crystal structure and evolution of a prokaryotic glucoamylase

The first crystal structures of a two-domain, prokaryotic glucoamylase were determined to high resolution from the clostridial species Thermoanaerobacterium thermosaccharolyticum with and without acarbose. The N-terminal domain has 18 antiparallel strands arranged in beta-sheets of a super-beta-sandwich. The C-terminal domain is an (alpha/alpha)(6) barrel, lacking the peripheral subdomain of eukaryotic glucoamylases. Interdomain contacts are common to all prokaryotic Family GH15 proteins. Domains similar to those of prokaryotic glucoamylases in maltose phosphorylases (Family GH65) and glycoaminoglycan lyases (Family PL8) suggest evolution from a common ancestor. Eukaryotic glucoamylases may have evolved from prokaryotic glucoamylases by the substitution of the N-terminal domain with the peripheral subdomain and by the addition of a starch-binding domain.
The Big Five and enduring marriages

The present investigation tested the relations between the Big Five dimensions of personality and the marital relationships of over 400 couples using both observational and questionnaire data. Four major findings emerged from these analyses. First, self-reports of neuroticism were positively correlated with negative interactions and negatively correlated with global evaluations of the marriage. Second, self-reports of agreeableness were negatively correlated with negative interactions and generally positively correlated with global evaluations of the marriage. Third, self-reports of openness were negatively correlated with observer reports of negative interactions. Fourth, self-reports of openness by wives were positively correlated with global reports of sexual satisfaction. These findings suggest that agreeableness and openness deserve increased attention as significant correlates of close relationships. Discussion emphasizes the importance of intrapersonal factors for understanding marital relationships.
Standard English: The Only Target for Nonnative Speakers of English?

An implicit assumption of most research on the acquisition of English as a second language is that standard English is the only target for nonnative speakers of English. The study reported in this article demonstrates that black English served as a target for Hispanic boys acquiring English as a second language in the New York City metropolitan area. In addition, the study shows that extensive peer contact with blacks was a necessary but not sufficient condition for the acquisition of two features of black English, negative concord and distributive be, and that choice of blacks as a reference group played no role in the acquisition of these two features. However, since contact did not account for all the variation and subjects made comments indicating that they had affective responses to input, the study suggests that the concept of reference group should be revised rather than abandoned.
Synthesis and electrophoretic deposition of magnetic nickel ferrite nanoparticles

Powders with particle size ∼5–15 nm of nickel ferrite have been synthesized chemically from aqueous precursor solutions. From the structural and magnetic properties, it is determined that the synthetic material possesses high NiFe2O4 phase purity and controllable particle size. The optimum calcination temperature is found to be ∼500 °C, at which the NiFe2O4 particles exhibit a saturation magnetization of 2800 G, and a particle size of about 10 nm. The particles are then deposited onto silicon substrates by electrophoretic deposition (EPD) process. The Ni ferrite particles are suspended in a medium of isopropyl alcohol with magnesium nitrate and lanthanum nitrate salts as charging agents. The transportation of particles to the substrate surface is assisted by applied electric field and particles adhere to the substrate surface by a glycerol based surfactant. The magnetic response of the EPD film has been investigated by vibrating sample magnetometer (VSM) measurements.
Ultraviolet spectra of polyfluoropolyphenyls

Abstract The ultraviolet absorption spectra of a series of polyfluoropolyphenyls (4H-nonafluorobiphenyl, 4H-tridecafluoroterphenyl and 4H-septadecafluoroquatraphenyl) are determined and compared to their nonfluorinated analogs. The spectra are interpreted in terms of a resonance interaction between skewed benzene rings.
A token-based routing mechanism for GMPLS-controlled WDM networks

Abstract This paper analyzes destination initiated reservation for Generalized Multi-Protocol Label Switching (GMPLS) based wavelength division multiplexing (WDM) networks and determines, via simulation, probabilities of both forward blocking and backward blocking. During light traffic load, any degradation in performance is due to backward blocking, whereas during heavy traffic load forward blocking dominates. In order to minimize performance degradation due to blocking, this paper proposes a token based routing scheme that is capable of searching for the availability of more than one route from source to destination, meeting the desired quality of service (QoS). Extensive simulation results show that the proposed technique significantly improves the blocking performance and setup delay.
Safely Modulating the Immune System in Regenerative Medicine

The destruction of pluripotent stem cell-derived grafts by the host immune system presents a significant barrier to clinical translation of cell therapies. Pearl et al. (2011) report in this issue of Cell Stem Cell that a brief, nontoxic immunosuppressive regimen, achieved by blockade of leucocyte costimulatory pathways, may overcome this problem.
Effect of nonstructural to structural carbohydrate ratio on rate and extent of nutrient utilization in situ

Abstract The objective was to relate differences in the chemical composition of the cell soluble and cell wall fractions and relate this to rate and extent of nutrient utilization by rumen microorganisms when diets were formulated to vary in nonstructural carbohydrate (NSC) to structural carbohydrate (SC) ratio. Nine diets were formulated to be similar in crude protein, acid detergent fiber, net energy for lactation, soluble protein, calcium and phosphorous. The diets, formulated from 16 different forage and grain sources, varied in NSC:SC ratio from 0.7 to 2.5, resulting in forage:concentrate ratios varying from 40:60 to 80:20. Diets were weighed into duplicate nylon bags and incubated in the rumen of one of two lactating cows for 2, 4, 8, 12, 18, 24, 48 and 100 h. No relationship was observed between NSC:SC ratio and rate or extent of dry matter, neutral detergent fiber or total nonstructural carbohydrate disappearance. However, in all cases > 95% of the variation in rate and extent of nutrient disappearance could be explained by the proportion of sugars (arabinose, xylose, glucose) in diet dry matter or cell wall. Composition of the sugars in the carbohydrate fraction of individual feedstuffs or total mixed diets may provide useful information when predicting nutrient utilization by ruminal microorganisms.
Engineering Application of Oxygen Laser-Induced Fluorescence Temperature Measurements in Aerodynamic Flows

Oxygen laser-induced e uorescence was studied experimentally to quantify signie cant error and uncertainty sources and to evaluate the technique feasibility for gas temperature measurements in the 1 ‐6-atm, 300‐500-K regime. The dominant uncertainty source is quantum noise. For low-speed e ows, the dominant error source is nonlinear process errors originating from oxygen ion e uorescence and saturation. For e ows where the pressure is unknown or variable, collisional quenching may introduce an additional error up to 3 K/atm. For high-speed e ows above 300 K, the dominant error source is the slow vibrational relaxation time of oxygen molecules. The optimum experimental conditions are determined by budgeting the allowable temperature inaccuracy to various uncertainty and error sources. In general, the nonlinear process errors limit the laser e uence that may be used, and the quantum noise determines the minimum number of laser shots per measurement.
Extraction of near interface trap density in top gated graphene transistor using high frequency current voltage characteristics

Graphene as a material has created a lot of interest due to properties like high saturation velocity [1], high current carrying capacity, ambipolar characteristics [2] and high transconductance. These properties make graphene based transistors a promising candidate for high frequency applications. Recently, there have been [2–3] demonstration of RF mixers with graphene transistors. Traditional DC measurements are not sufficient when considering graphene transistors for high frequency circuit design, making it essential to study the transistor IV performance at operating frequencies >GHz. In this work we outline an RF IV extraction technique and use physics based analytical model to evaluate the performance of graphene transistors with HfO 2 high-κ dielectric.
Species and Sex Differences in Selenium Inhibition of Hepatic Drug Metabolism in Rodents

Hepatic microsomal drug metabolism was assessed in male and female rats, mice and hamsters 72 hr after administration of sodium selenite. The greatest inhibitory effect of selenium on hepatic drug metabolism occurred in male rats where the magnitude of reduction in microsomal metabolism by selenium treatment of ethylmorphine and aminopyrine was disproportionately greater than the decrease in either cytochrome P-450 levels or metabolism of aniline. In contrast, the inhibition of metabolism of the three substrates in female mice and the decrease in ethylmorphine-N-demethylase in male mice were similar in magnitude to the reduction observed in cytochrome P-450 content. Hepatic microsomal metabolism in male and female hamsters was relatively resistant to the inhibitory effects of selenium. The inhibition of drug metabolism by selenium may reflect a specific effect of selenium on selected isozymes of cytochrome P-450.
Fractionation of northern copperhead venom by ion-exchange chromatography: Preliminary characterization of the primary lethal fraction

J. B. Moran, S. Y. Y. Pang, D. W. Martin and C. R. Geren. Fractionation of northern copperhead venom by ion-exchange chromatography: preliminary characterization of the primary lethal fraction. Toxicon17, 499–510, 1979.—Venom of the northern copperhead (Agkistrodon contortrix mokasen) has been fractionated by ion-exchange chromatography and the resulting fractions examined for lethal and enzymatic activities. Of the nine distinct fractions obtained by carboxymethyl cellulose chromatography, five were lethal to mice. One of these five accounted for 65–70% of the lethality of whole venom. This fraction, TII, under our experimental conditions appeared to be dissociated from enzymatic activities found both in the whole venom and in other carboxymethyl fractions. Phospholipase, protease and ester-hydrolytic activities appeared in significant quantities in both the fraction of the venom not retained by carboxymethyl cellulose and in various fractions which were retained. Re-chromatography of the non-retained fraction showed that these activities were distinct and not the result of a column overload. The non-retained fraction contained virtually all of the l-amino acid oxidase activity. This fraction also contained a component which caused hemorrhage in mice and a calcium-independent thrombin-like pro-coagulant activity. This fraction was further separated by diethylaminoethyl cellulose chromatography which revealed that the pro-coagulant activity consisted of at least two separate entities. TII had an ld50 value in mice of 1–2 μg/g body weight, which is 10–20 times more potent than whole venom. This fraction has been shown to abolish the muscle response to indirect stimulation and acetylcholine, but not KCl in the chick biventer cervicis neuromuscular junction assay. Its lethality to mice is destroyed by incubation with proteases or at high pH. It is fairly heat stable with lethality being retained after 20 min at 100°C. Toxicity is lost when this fraction is dialyzed against 5 mM sodium acetate, but not when dialyzed against Tyrode's solution or 100 mM sodium acetate. Chemical modification studies have shown that the lethal activity of this fraction may have disulfide, tryptophan, histidine and possibly arginine dependency.
Telomeric properties of C4A4-homologous sequences in micronuclear DNA of Oxytricha fallax

The hypotrichous ciliated protozoan Oxytricha fallax has both macronuclei and micronuclei. The short DNA molecules of the macronucleus are terminated with repeats of the octanucleotide C4A4. Micronuclear DNA carries a family of long sequence blocks, which share a consensus restriction map and have homology with the C4A4 repeats. Each block contains a 3 to 6 kb subregion, which is refractory to all restriction enzymes tested and includes the C4A4 homology. We conclude that these refractory sequences are at DNA termini because Sau 3A fragments containing them fail to ligate to form circles, and they are rapidly degraded by Bal 31 nuclease. These terminal C4A4-homologous sequence blocks likely represent micronuclear chromosomal telomeres. Possible relationships between these sequences, internal micronuclear C4A4 repeats, and macronuclear DNA termini are discussed.
Problems and progress in multidimensional systems theory

The paper presents the troubles and trends of research in multidimensional system theory, with special emphasis in the areas of multivariable network analysis and synthesis, and multidimensional digital filters. The possibilities as well as perils of extending established single-dimensional techniques to multidimensional situations is discussed, and the nature and effect of certain fundamental problems present when applying the mathematics of several variables is given cognizance. Open problems are identified at various stages and some recommendations for future research are made.
The Future of Employment-Based Health Insurance after the Patient Protection and Affordable Care Act

In the United States, unlike in all other advanced industrial states, health care is financed principally through employment-based health insurance. In 2009, more than 156 million individuals under the age of sixty-five, or 59% of that population, were covered by employment-based health insurance. On March 21, 2010, President Obama signed the Patient Protection and Affordable Care Act (PPACA). Described as seminal as the enactment of the Employee Retirement Income Security Act (ERISA), PPACA fundamentally reforms the American health care system. PPACA, however, does not eliminate the system’s reliance on employment-based health insurance. Instead, it builds on, and arguably strengthens, the employment-based system. This Article discusses how PPACA is likely to affect employers’ willingness to sponsor employment-based health insurance. The Article begins by providing a brief history of employment-based health insurance in the United States. It then discusses the advantages and disadvantages of this system. In doing so, it focuses on four separate aspects of employment-based health insurance: (1) its favorable tax treatment, (2) its cost, (3) the fact that the employer acts as an agent for its employees when it purchases health insurance, and (4) the labor incentives it creates. The Article then turns to the three incentives PPACA creates with respect to the provision of employment-based health insurance: (1) the large employer “pay-or-play” mandate, (2) the small employer tax credit, and (3) the excise tax on so-called “Cadillac” plans. It describes and discusses how each of these incentives is likely to affect employers’ willingness to offer employment-based health insurance. It concludes that, at least in the short run, PPACA is unlikely to change the American health care system’s reliance on employment-based health insurance.
The Relative Influence of Calcium Intake and Vitamin D Status on Serum Parathyroid Hormone and Bone Turnover Biomarkers in a Double-Blind, Placebo-Controlled Parallel Group, Longitudinal Factorial Design

Background: Adequate calcium and vitamin D are needed to maintain calcium balance. Objective: Our objective was to examine the influence of calcium intake and vitamin D exposure separately and their interaction on biomarkers of calcium sufficiency. Design: Healthy men and women, age 20–80 yr, were randomly allocated to four groups: 1) double placebo, 2) calcium (1200 mg daily) plus placebo, 3) vitamin D3 (100 μg) plus placebo, and 4) vitamin D3 and calcium. Fasting serum and urine as well as serum and urine 2 h after a calcium load (600 mg of calcium carbonate) were obtained at baseline and 3 months. Results: Ninety-nine participants were randomized; 78 completed the study. Baseline demographics, protein intake and laboratory studies did not differ among the four groups. Study medication compliance was 90%. Fasting bone turnover markers declined after 3 months only in the two groups given calcium supplements and increased in the vitamin D3 plus placebo calcium group. The calcium load resulted in a decreas...
Review of digital control techniques for automotive DC-DC converters

Electric and hybrid electric vehicles need a power plant that includes DC-DC converters. While using these converters, their control plays an important role in the overall performance of the vehicle. Due to their several drawbacks including poor communications, analog control schemes are not suitable for the automotive industry, whereas digital control methods successfully meet the demands. Various types of digital control techniques for DC-DC converters are studied and classified in this paper. The drawbacks and advantages of each method are described.
Developing an Online Accessible Science Course for All Learners

The American with Disabilities Act (ADA) of 1990 was a landmark legislative initiative that outlined the protection of individuals with disabilities. Title III of the ADA directs that public facilities make reasonable efforts to control discrimination and support accessibility policies, practices, and procedures (Council for Exceptional Children, 1994). The 1997 amendment of the Individuals with Disabilities Education Act (U.S. Congress, 1999) stipulates that students with disabilities are to be educated in the general education curriculum. Institutions of Higher Education are not immune from these policies. In addition, common actions like course development and teaching must include considerations and compliance with the ADA and IDEA guidelines. These guidelines have also extended to the realm of computer technology in recent years (e.g., Chalfen & Farb, 1996; Mendle, 1995) especially as they pertain to online delivery of instruction. The U. S. Access Board (2001), a governing body charged with helping U.S. federal agencies reach Web accessibility, announced a set of guidelines that comply with Section 508 of the 1998 Rehabilitation Act. The result was that all federal agencies had to alter and or develop Web sites that were accessible to those with disabilities. Web page authors can also integrate the same guidelines into generic Web sites, as well as online courses offered at universities (e.g., Robertson, 2002; Robertson & Harris, 2003).
IMPLEMENTING URBAN HOUSING REHABILITATION PROGRAMS: A COMPARISON OF THE FEDERAL AND STATE EXPERIENCES1

Recent changes in federal housing rehabilitation policy have shifted the emphasis from single-family to multi-family units and from direct federal delivery of housing services to state and local administration. To discover the implications of this shift, this study compares the implementation of a state home improvement loan program with the financing and administration approach adopted by the federal Section 312 and Community Development Block Grant loan programs prior to 1983. A survey of borrowers who participated in the state and federal rehabilitation loan programs reveals that both types of programs assist the “incumbent up grader,” both increased the value of property, both achieved high levels of borrower satisfaction, and both concentrated on the single-family unit. Differences, however, did arise between the federal and state programs in that the state program borrowers were encouraged to conduct preventive maintenance, while the federal programs advanced social goals of serving a greater number of low-income homeowners with larger loan amounts at lower interest rates. This comparison study does not support the federal withdrawal from providing direct single-family rehabilitation loans because it can supplement the bond-market orientation of the state approach with a social targeting function.
Patterns of Nuclear Genetic Variation in the Poecilogonous Polychaete Streblospio benedicti

The evolution of marine larvae is replete with transitions in trophic mode, but little is known about how, at the genetic level, these transitions are achieved. Basic parameters, including the number of underlying loci, their molecular characteristics, and the population-genetic processes that drive transitions remain unknown. Streblospio benedicti, an abundant benthic polychaete with heritable poecilogony, provides a unique genetically tractable system for addressing these issues. Individuals of S. benedicti vary in diverse aspects of development. Some females produce small, planktotrophic larvae, whereas others produce large, yolky larvae capable of settling without feeding. Here, I present estimates of basic features of nuclear genetic variation in S. benedicti to lay the foundations for subsequent efforts to understand the genetic basis of poecilogony. Sequence of ∼20 kb of random nuclear DNA indicates that the nucleotide composition, at 62.1% A + T, is typical of lophotrochozoan genomes. Population-genetic data, acquired by sequencing two loci (∼2500 bp) in multiple animals of each developmental morph, indicate that the morphs exhibit very little differentiation at random loci. Nucleotide heterozygosity (θπ) is ∼0.5-1% per site, and linkage disequilibrium decays within a few kilobases (ρ ∼ 3 × 10(-3) per site). These data suggest that genetic mapping by association will require a high density of markers, but linkage mapping and identification of regions of elevated inter-morph differentiation hold great promise.
Analysis of modern and Pleistocene hydrologic exchange between Saginaw Bay (Lake Huron) and the Saginaw Lowlands area

Two numerical models, one simulating present groundwater flow conditions and one simulating ice-induced hydraulic loading from the Port Huron ice advance, were used to characterize both modern and Pleistocene groundwater exchange between the Michigan Basin and near-surface water systems of Saginaw Bay (Lake Huron) and the surrounding Saginaw Lowlands area. These models were further used to constrain the origin of saline, isotopically light groundwater, and porewater from the study area. Output from the groundwater-flow model indicates that, at present conditions, head in the Marshall aquifer beneath Saginaw Bay exceeds the modern lake elevation by as much as 21 m. Despite this potential for flow, simulated groundwater discharge through the Saginaw Bay floor constitutes only 0.028 m 3 s-' (∼1 cfs). Bedrock lithology appears to regulate the rate of groundwater discharge, as the portion of the Saginaw Bay floor underlain by the Michigan confining unit exhibits an order of magnitude lower flux than the portion underlain by the Saginaw aquifer. The calculated shoreline discharge of groundwater to Saginaw Bay is also relatively small (1.13 m 3 s - 1 or ∼40 cfs) because of low gradients across the Saginaw Lowlands area and the low hydraulic conductivities of lodgement tills and glacial-lake clays surrounding the bay. In contrast to the present groundwater flow conditions, the Port Huron ice-induced hydraulic-loading model generates a groundwater-flow reversal that is localized to the region of a Pleistocene ice sheet and proglacial lake. This area of reversed vertical gradient is largely commensurate with the distribution of isotopically light groundwater presently found in the study area. Mixing scenarios, constrained by chloride concentrations and δ 1 8 O values in porewater samples, demonstrate that a mixing event involving subglacial recharge could have produced the groundwater chemistry currently observed in the Saginaw Lowlands area. The combination of models and mixing scenarios indicates that structural control is a major influence on both the present and Pleistocene flow systems.
The reverse transcriptase sequence of human immunodeficiency virus type 1 is under positive evolutionary selection within the central nervous system.

The human immunodeficiency virus type 1 (HIV-1) enters the central nervous system (CNS) during the acute phase of infection and causes AIDS-related encephalitis and dementia in 30% of individuals. Previous studies show that HIV-1 sequences derived from the CNS of infected patients, including the sequence encoding reverse transcriptase (RT), are genetically distinct from sequences in other tissues. The hypothesis of the current study is that the RT sequence of HIV-1 is under positive selection within the CNS. Multiple alignments of non-CNS-derived and CNS-derived HIV-1 RT sequences were constructed using the ClustalW 1.8 program. The multiple alignments were analyzed with the Synonymous/Nonsynonymous Analysis Program. Codon positions 122–125, 135–149, and 166–212 of the CNS-derived RT sequences underwent a greater accumulation of nonsynonymous than synonymous substitutions, which was markedly different from the analysis results of the non-CNS-derived RT sequences. These residues are located in the finger and palm subdomains of the RT protein structure, which encodes the polymerase active site. The analysis of CNS-derived partial-length RT sequences that encompass these regions yielded similar results. A comparison of CNS-derived RT sequences to a non-CNS-derived RT consensus sequence revealed that a majority of the nonsynonymous substitutions resulted in a specific amino acid replacement. These results indicate that reverse transcriptase is under positive selection within the CNS. The amino acid replacements were visualized on a three-dimensional structure of HIV-1 RT using the Sybyl software suite. The protein structure analysis revealed that the amino acid replacements observed among the CNS-derived sequences occurred in areas of known structural and functional significance.