cssi/SciSciGPT-SciSciNet huggingface dataset:
Screening for acquired cystic kidney disease: A decision analytic perspective

Screening for acquired cystic kidney disease: A decision analytic perspective. Acquired cystic kidney disease (ACKD) increases the risk of renal malignancy, and many authors suggest routine screening of dialysis patients for ACKD and renal tumors. However, they have defined neither the target population, the optimal screening strategy, the magnitude of its benefit, nor its risk. We used decision analysis to evaluate strategies of performing either computed tomography (CT) or ultrasound every three years on all dialysis patients and annually on patients found to have cysts. We compared these strategies to a strategy of seeking cysts and cancer only if these are clinically suspected. The baseline analysis shows that both CT and ultrasound may decrease cancer deaths by half for patients with a life expectancy of 25 years. Screening for ACKD offers these patients as much as a 1.6 year gain in life expectancy. However, for the majority of patients beginning renal replacement therapy, age or comorbid disease substantially limits life expectancy. For such patients, the gain in life expectancy from an ACKD screening program is measured in days. Sensitivity analyses show that the benefit of screening depends on the rate of malignant transformation, which needs better definition. The gain in life expectancy does not appear to be large enough to justify an ACKD screening program for the entire ESRD population. However, for the youngest and healthiest patients, a screening program would be of benefit. The magnitude of this benefit is uncertain, because the analysis was consistently biased in favor of the screening strategies.
Determination of the atomic weight of 28Si-enriched silicon for a revised estimate of the Avogadro constant.

The much anticipated overhaul of the International System of Units (SI) will result in new definitions of base units in terms of fundamental constants. However, redefinition of the kilogram in terms of the Planck constant (h) cannot proceed without consistency between the Avogadro and Planck constants, which are both related through the Rydberg constant. In this work, an independent assessment of the atomic weight of silicon in a highly enriched 28Si crystal supplied by the International Avogadro Coordination (IAC) was performed. This recent analytical approach, based on dissolution with NaOH and its isotopic characterization by multicollector inductively coupled plasma mass spectrometry, is critically evaluated. The resultant atomic weight Ar(Si) = 27.976 968 39(24)k=1 differs significantly from the most recent value of Ar(Si) = 27.976 970 27(23)k=1. Using the results generated herein for Ar(Si) along with other IAC measurement results for mass, volume, and the lattice spacing, the estimate of the Avogad...
Use of differential isotopic labeling and mass spectrometry to analyze capacitation-associated changes in the phosphorylation status of mouse sperm proteins.

Mammalian sperm need to reside in the female reproductive tract for a finite period of time before acquiring fertilizing competence. The biochemical changes associated with this process are collectively known as “capacitation”. With the use of the mouse as an experimental model, we have previously demonstrated that capacitation is associated with a cAMP-dependent increase in protein tyrosine phosphorylation. However, little is known about the identity and function of the protein targets of this phosphorylation cascade. In the present work, we have used differential isotopic labeling coupled with immobilized metal affinity chromatography (IMAC)-based phosphopeptide enrichment and analysis on a hybrid linear ion trap/FT-ICR mass spectrometer to measure the changes in protein phosphorylation resulting from the capacitation process. As no kinase activators and/or phosphatase inhibitors were used in the preparation of the sperm samples, phosphorylated residues identified in this study represent in vivo sites o...
Acute toxicities of Cd2+, Cr+6, Hg2+, Ni2+ and Zn2+ to estuarine macrofauna

Static acute toxicity bioassays were conducted at 20 degrees C and 20 o/33 salinity with CdCl2-2 1/2 H20, K2CrO4, HgCl2, NiCl2-6H2O, and ZnCl2 using adults of starfish, Asterias forbesi; sandworm, Nereis virens; hermit crab, Pagurus longicarpus; softshell clam, Mya arenaria; mudsnail, Nassarius obsoletus; and mummichog, Fundulus heteroclitus, a fish. Concentrations (mg/L metal) fatal to 50% of the organisms in 168 hr ranged from 0.004 (clam) to 0.8 (mummichog) for mercury; 0.7 (clam, worm, crab and starfish) to 40.0 (mummichog) for cadimium; 0.2 (crab) to 52.0 (mummichog) for zinc; 0.7 (sandworm) to 44.0 (mummichog) for hexavalent chromium; and 13.0 (starfish) to 150.0 (mummichog) for nickel. Biocidal action was restricted to a relatively narrow range for all species-metals combinations tested: i.e., mean LC-75/LC-25 rations for individual metals at 168 hr ranged between 2.82 (Zn) and 6.02 (Cd); for individual species this ratio extended from 2.76 (fish) to 4.46 (clam). It appears that acute toxicity evaluation of potentially hazardous metals in saline environments requires utilization of at least several representative species from divergent taxonomic and ecological niches.
Elevated Lead Levels in Farmed American Alligators Alligator mississippiensis Consuming Nutria Myocastor coypus Meat Contaminated by Lead Bullets

con- tain fragments of lead bullets. This report details the clinical, toxicological and patho- logical findings associated with an unusual case of lead poisoning in commercially reared alligators. Louisiana Department of Wildlife and Fisheries data indicate sales of alligator hides and meat represent an aquaculture in- dustry in the state with a 1995 production valued at US $11 million. The animals are typically raised indoors in buildings con- taining multiple pens with shallow pools provided with raised platforms for feeding and resting. At optimum temperatures of 30-32 C, market-sized alligators, averaging 120 cm, can be produced in approximately 2 yr. Diets on most farms consist of a com- bination of commercially available pellets, chicken parts, whole fish, and ground nutria carcasses. Relative proportions of the dif-
A mediator methylation mystery: JMJD1C demethylates MDC1 to regulate DNA repair

Mediator of DNA-damage checkpoint 1 (MDMDC1) has a central role in repair of DNA double-strand breaks (DSBs) by both homologous recombination and nonhomologous end joining, and its function is regulated by post-translational phosphorylation, ubiquitylation and sumoylation. In this issue, a new study by Watanabe et al. reveals that methylation of MDMDC1 is also critical for its function in DSB repair and specifically affects repair through BRCA1-dependent homologous recombination.
Procainamide pharmacokinetics in patients with acute myocardial infarction or congestive heart failure

Abnormal procainamide pharmacokinetics (prolonged half-life and decreased volume of distribution) and pharmacddynamics (decreased threshold for the suppression of premature ventricular complexes) have been suggested in patients with acute myocardial infarction or congestive heart failure, or both. To better define procainamide kinetics, 37 patients in the acute care setting received intravenous procainamide (25 mg/min, median dose 750 mg) with peak and hourly blood samples taken over 6 hours. Compared with the 10 control patients, the 12 patients with acute myocardial infarction and the 15 patients with congestive heart failure had normal procainamide pharmacokinetics with respect to half-life (2.3 ± 1.0, 2.5 ± 0.9 and 2.6 ± 0.8 hours, respectively), volume of distribution (1.9 ± 0.7, 1.8 ± 0.4 and 1.8 0.5 liters/kg, respectively), clearance (11.3 ± 7.5, 9.3 ± 3.6 and 9.1 ± 3.5 ml/min per kg, respectively) and unbound drug fraction (66 ± 9, 66 ± 9 and 69 4%, respectively). Low thresholds for greater thin 85% premature ventricular complex suppression were confirmed in these patients (median 4.7 μg/ml in patients with acute myocardial infarction and 3.3 μg/ml in patients with congestive heart failure). Thus, differences in the response of premature ventricular complexes to procainamide reflect electropharmacologic differences dependent on clinical setting rather than pharmacokinetic abnormalities. Furthermore, the reduction of procainamide dosing in patients with acute myocardial infarction or congestive heart failure, based solely on prior kinetic data, may result in inappropriate antiarrhythmic therapy.
The effect of alloying on the properties of (Nb,Ti)Cr2 C15 Laves phases

Abstract The effect of composition on the ternary (NbCr 2 –TiCr 2 ) C 15 phase properties has been investigated, focusing upon the defect structure, elastic properties, and mechanical behavior. The C 15 phase field is continuous between NbCr 2 –TiCr 2 , with a maximum phase field width of at least 7 at.% solubility. The defect mechanism is governed by anti-site constitutional defects for all alloys. Mechanically, the alloys display a maximum in hardness in the center of the ternary phase field (and a minimum of toughness). The ternary phase field has features that are characteristic of solid-solution strengthening mechanisms. Finally, the elastic properties indicate that the alloys become stiffer in the middle of the ternary phase field. The best compromise of properties occurs furthest from stoichiometry in the ternary phase field at the nominal composition of Nb 19 Ti 19 Cr 62 . The relationships between the defect structure, elastic properties, and mechanical response for the C15 phases are discussed using a combination of atomic size arguments and electronic structure analyses. From these relationships, alloy design strategies for NbCr 2 -based alloys are evaluated.
Automated conformational analysis and structure generation

An approach for automatically and rapidly searching a molecule's conformational space to determine low-energy conformations is described. The method takes a simple 2D description of the molecule (atom types and connectivity), recognizes the presence of conformational units about which it has ‘knowledge’ and generates structures by template joining. Some of the algorithms which can be used to search the conformational space are described, as are methods to manipulate conformational information. Such an approach may be used to generate multiple conformations which may be further refined or stored in some form of 3D database.
ANTAGONISTIC EFFECT OF CPTA AND FAR‐RED LIGHT ON THE CAROTENOGENESIS IN LUTESCENT TOMATOES1

Yellow lutescent tomatoes normally devoid of lycopene can be induced to produce this red pigment when treated with bioregulators such as CPTA, (2-(4-chlorophenylthio)-triethylamine hydrochloride). Red light and CPTA combination stimulated the accumulation of 225 μg/g of lycopene in mature white lutescent tomatoes after a 12-day ripening period. Tomatoes treated with CPTA but ripened in the dark produced 67 μg/g of lycopene. Far-red light treatment of the CPTA treated tomatoes produced only 25 μg/g of lycopene. Analysis of other carotenoids showed a similar trend indicating a quantitative but not a qualitative change in carotenogenesis in lutescent tomatoes as affected by light and by bioregulators. The antagonistic effect of far-red light toward CPTA suggested that the two effectors might work at the same reactive site in tomato cells.
Assessment of gastric accommodation: overview and evaluation of current methods.

Abstract Gastric accommodation is considered important in the pathophysiology of several upper gastrointestinal disorders including functional dyspepsia. The gold standard for its measurement is the barostat-balloon study which requires intubation. The aim was explore the reliability and performance characteristics of the techniques proposed for measurement of gastric accommodation. We undertook a literature search using MEDLINE with a broad range of key words. The accommodation reflex and its control are briefly described, based on human data. The performance characteristics of the intragastric barostat, transabdominal ultrasound, magnetic resonance imaging, single photon emission computed tomography, and satiation drinking tests are described. For each technique, we summarize the following: principle, validation studies, advantages, disadvantages, and potential applications. Three-dimensional methods to measure gastric volume non-invasively are promising and among the best validated to date. Simpler techniques would be of considerable appeal for clinical and research studies, but further validation is necessary before satiation drinking tests can be used as surrogates for more sophisticated measurements of gastric accommodation.
Electrospray ionization-Fourier transform ion cyclotron mass spectrometry using ion preselection and external accumulation for ultrahigh sensitivity.

The dynamic range of Fourier transform ion cyclotron mass spectrometry (FTICR) is typically limited by the useful charge capacity of an FTICR cell (to ∼106 to 107 elementary charges) and the minimum number of ions required to produce a useful signal (∼102 elementary charges). We show that the expansion of the dynamic range by 2 orders of magnitude can be achieved by preselecting lower abundance species in a quadrupole interface to an electrospray ionization (ESI) source. Ion preselection is then followed by ion accumulation in external to the FTICR cell a linear (2-D) quadrupole trap and subsequent transfer to the region of high magnetic field for gated trapping in the FTICR cell. Two modes of ion preselection, using either the quadrupole filtering mode or rf-only dipolar excitation, were studied and mass resolutions of 30 to 100 were achieved for selective external ion accumulation of peptides and proteins with molecular weights ranging from 500 to 17,000 Da. The ability to selectively eject the most abundant species before trapping in the FTICR has enormous practical benefits for increasing the sensitivity and dynamic range of measurements.
Left Ventricular Pressure-Volume Characteristics in Congenital Heart Disease

The continuous pressure-volume relationships throughout the cardiac cycle were evaluated in children with tetralogy of Fallot, isolated ventricular septal defect, and patent ductus arteriosus. Biplane cineangiocardiography and simultaneous left ventricular pressures were utilized for data acquisition. Normal pressure-volume loops demonstrated only small changes in left ventricular volume during the isovolumic periods. In tetralogy of Fallot, there was a decrease in left ventricular volume during the interval of the "isovolumic" contraction with 12 to 43% of the total stroke volume being ejected during this phase. A decrease in left ventricular volume during this time was also found in large ventricular septal defects; however, volume changes during this interval were minimal in those patients judged to have small defects. With large left-to-right shunts of comparable magnitude, the relative area of the pressure-volume loop was greater in patent ductus arteriosus as compared with ventricular defects. Both ...
A usability comparison of PDA-based quizzes and paper-and-pencil quizzes

In the last few years, schools and universities have incorporated personal digital assistants (PDAs) into their teaching curricula in an attempt to enhance students' learning experience and reduce instructors' workload. One of the most common uses of PDAs in the classroom is as a test administrator. This study compared the usability effectiveness, efficiency, and satisfaction of a PDA-based quiz application to that of standard paper-and-pencil quizzes in a university course. Effectiveness was measured as students' quiz scores and through a mental workload questionnaire; efficiency was the time it took students to complete each quiz; and satisfaction was evaluated using a subjective user satisfaction questionnaire. The study showed the PDA-based quiz to be more efficient, that is, students completed it in less time than they needed to complete the paper-and-pencil quiz. No differences in effectiveness and satisfaction were found between the two quiz types. Computer anxiety was not affected by the quiz type. For these reasons, as well as other advantages to both students (e.g., real-time scoring) and teachers (e.g., less time spent on grading), PDAs are an attractive test administration option for schools and universities.
Review of Feminist New Testament Studies: Global and Future Perspectives, edited by Kathleen O’Brien Wicker et al.

Stephen D. Moore reviews Feminist New Testament Studies: Global and Future Perspectives , edited by Kathleen O’Brien Wicker, Althea Spencer Miller and Musa W. Dube. Religion/Culture/Critique series (New York: Palgrave Macmillan, 2005).
Home networking and HCI: what hath god wrought?

For much of the industrialized world, network connectivity in the home is commonplace. Despite the large number of networked homes, even the most technically savvy people can have difficulties with home network installation and maintenance. We contend that these problems will not disappear over time as the networking industry matures, but rather are due to structural usability flaws inherent in the design of existing network infrastructure, devices, and protocols. The HCI community can offer a unique perspective to overcoming the challenges associated with home networking. This paper discusses why home networking is difficult, based on analysis of historical, social, and technical factors. It explores how the designs of existing home networking technologies have implications for usability, and examines a range of models for addressing these usability challenges. The paper concludes with a discussion of how these models may impact future research efforts in both HCI and networking.
Current controversies in nonoperative management of Type II odontoid fractures in the elderly

Abstract The study design was a review of the literature. The objective was to assess the outcomes of nonoperative management of Type II odontoid fractures in the elderly population. Type II odontoid fractures in the elderly population are associated with high morbidity and mortality rates, and the current treatment recommendation is quite controversial. This article reviews the current literature on nonoperative versus operative treatment of Type II odontoid fractures in the elderly population, in hopes of drawing conclusions for the best approach to these patients. MEDLINE and PubMed databases were searched to identify articles. Studies included were those involving elderly patients with Type II odontoid fractures, who were managed nonoperatively. Studies assessing the different methods of operative fixation were excluded. An algorithm taking into account the morbidities associated with the treatment option versus the long-term outcomes in elderly patients with Type II odontoid fractures would be extremely beneficial for spine surgeons to aid in deciding whether or not to operate. Nondisplaced fractures may be appropriately treated nonoperatively in a collar with close follow-up and early mobilization. Halo–vest immobilization should be used sparingly in the elderly population, as it is associated with significant morbidity. Cervical collars appear to have less morbidity than halo–vest immobilization with success in the less displaced fracture patterns. Lastly, operative treatment for displaced, unstable fractures can improve patient outcomes.
From Migrant to Minority: Hmong Refugees and the Social Construction of Identity in the United States*

La perspective de construction sociale de l'ethnicite amene a penser qu'il est probable que les migrants ne se considerent pas comme des minorites ethniques meme lorsqu'ils ont objectivement ce status. Les donnees obtenues par interviews aupres de 40 leaders de refugies hmong concordent avec cette these. Un tiers montre une orientation complete de type migrant, tandis que seul un petit nombre se considere completement comme une minorite. Cependant, un tiers montre des orientations de type minorite a l'origine. L'orientation de type migrant favorise la communaute ethnique et les problemes lies a la migration. L'orientation de type minorite, quant a elle, favorise les relations avec la societe americaine et les problemes lies aux institutions americaines. L'A. confirme les resultats de recherches precedentes selon lesquels l'orientation de type minorite est plus courante chez les leaders qui ont le plus grand potentiel d'adaptation reussie. Mais contrairement aux resultats anterieurs, les resultats de l'A. suggerent que la conscience ethnique chez les migrants depend non seulement de leurs attitudes envers l'assimilation, mais aussi du fait qu'ils attribuent l'inegalite soit a leur statut de nouveaux venus dans une societe d'accueil, soit a leur statut de minorite dans une hierarchie raciale et ethnique
Synthesis and chemical stability of glucocorticoid-dextran esters: potential prodrugs for colon-specific delivery

Dextran ester prodrugs have been proposed as a means of delivering drug to the colon. In this study, methylprednisolone and dexamethasone were covalently attached to dextran (Mw = 72 600) by the use of a succinate linker. In addition, dexamethasone was attached by glutaric acid to investigate the effect of linker molecule on hydrolysis kinetics. The kinetics of degradation of the hemiesters and corresponding dextran conjugates were measured as a function of pH and temperature. Intramolecular migration of the linker molecule from the 21- to the 17-position on the glucocorticoid occurred in all three hemiesters, although to a greater extent in methylprednisolone-hemisuccinate. The dextran conjugates were also incubated at 37°C, pH 6.8 and the chemical degradation half-lives were as follows: dexamethasone-succinate-dextran 75 h; dexamethasone-glutarate-dextran 103 h and methylprednisolone-succinate-dextran 82 h. Incubation of dexamethasone-21-hemisuccinate with rat gastrointestinal (GI) tract luminal contents indicated that the hemiester is hydrolyzed throughout the GI tract. Greatest esterase activity, however, was found in the small intestine. By contrast, little drug (< 3%) was released from dexamethasone-succinate-dextran during incubation with small intestinal contents despite the high esterase activity. Dexamethasone and dexamethasone-21-hemisuccinate were released at faster rates during incubation with cecum and colon contents. This combination of chemical stability and selective enzyme-mediated drug release in the large intestine indicates that these dextran prodrugs have potential in colon-specific delivery of glucocorticoids.
Metabolic engineering of a pentose metabolism pathway in ethanologenic Zymomonas mobilis

The ethanol-producing bacterium Zymomonas mobilis was metabolically engineered to broaden its range of fermentable substrates to include the pentose sugar xylose. Two operons encoding xylose assimilation and pentose phosphate pathway enzymes were constructed and transformed into Z. mobilis in order to generate a strain that grew on xylose and efficiently fermented it to ethanol. Thus, anaerobic fermentation of a pentose sugar to ethanol was achieved through a combination of the pentose phosphate and Entner-Doudoroff pathways. Furthermore, this strain efficiently fermented both glucose and xylose, which is essential for economical conversion of lignocellulosic biomass to ethanol.
A MOVING GRID METHOD FOR (1+1) DIMENSION

Abstract We develop a numerical method to create an adaptive grid in one plus one dimension which varies according to any given weight function of the spatial variable and the time. The grids are obtained by a nonstandard deformation method.
Treatment benefit functions for a drug abuse rehabilitation treatment system.

Abstract While generally justifying the large amount of money invested in the treatment effort, evaluation studies of treatment centers for drug addiction do not offer a rational method of allocating scarce resources among the various available treatment programs. The problem is further confounded by different costs associated with the different programs and also because clients rarely complete the prescribed treatment. We developed functional relationships between treatment outcomes and time in treatment that allow the inclusion of probable length of stay of patients and cost per week for a particular treatment program in the evaluation considerations. The model evolved from a drug addiction treatment system operating in Newark, New Jersey consisting of six different treatment centres. Treatment outcome measures are derived from a psychosocial questionnaire which was administered to patients at appropriate time intervals. The questionnaire probed into the important facets of human behavior as related to the use or non-use of drugs for non-medical reasons. Gompertz curves reflecting treatment benefit are computed for each treatment center by least square fit of the collected data to appropriate differential equations and used together with cost of treatment retention rates to compute expected net benefit for each treatment center. These enable the researcher to find the treatment centers with the best treatment outcome or alternately with the best expected cost benefit ratio for any patient type.
Cinéma Divinité: Religion, Theology, and the Bible in Film – Edited by Eric S. Christianson, Peter Francis and William Telford (eds)

Book reviewed: Cinema Divinite: Religion, Theology, and the Bible in Film, Eric S. Christianson, Peter Francis and William Telford (eds), SCM press 2005 (0-334-02988-0), xvii + 373 pp., pb £19.99
Employee Management on Large Ranches

On the Ground Managing people is a vital component of managing a large ranch. Employee management practices have an effect on turnover in any organization, and our study specifically examined management practices on ranches. Our study describes the state of employee management on large ranches and provides useful and practical information that may help ranch managers build their personnel management skills. Managers could potentially enhance employee performance by reviewing their operations management procedures and incentive structures and adjusting them as needed.
Formation of spinel-, hibonite-rich inclusions found in CM2 carbonaceous chondrites

We report petrography, mineral chemistry, bulk chemistry, and bulk isotopic compositions of a suite of 40 spinel-rich inclusions from the Murchison (CM2) carbonaceous chondrite. Seven types of inclusions have been identified based on mineral assemblage: spinel-hibonite-perovskite; spinel-perovskite-pyroxene; spinel-perovskite-melilite; spinel-hibonite-perovskite-melilite; spinel-hibonite; spinel-pyroxene; and spinel-melilite-anorthite. Hibonite-bearing inclusions have Ti-poor spinel compared to the hibonite-free ones, and spinel-hibonite-perovskite inclusions have the highest average bulk TiO 2 contents (7.8 wt%). The bulk CaO/Al 2 O 3 ratios of the inclusions range from 0.005 to 0.21, well below the solar value of 0.79. Hibonite-, spinel-rich inclusions consist of phases that are not predicted by condensation calculations to coexist; in the equilibrium sequence, hibonite is followed by melilite, which is followed by spinel. Therefore, hibonite-melilite or melilite-spinel inclusions should be dominant instead. One explanation for the “missing melilite” is that it condensed as expected, but was lost due to evaporation of Mg and Ca during heating and melting of spherule precursors. If this theory were correct, melilite-poor spherules would have isotopically heavy Mg and Ca, assuming Rayleigh fractionation accompanied evaporation. Except for one inclusion with F Mg = 4.3 ± 2.6‰/amu and another with isotopically light Ca ( F Ca = −3.4 ± 2.0‰/amu), however, all the inclusions we analyzed have normal isotopic compositions within their 2σ uncertainties. Thus, we found no evidence for significant mass-dependent fractionation. Conditions necessary for non-Rayleigh evaporation are unlikely if not unrealistic, and our preferred explanation for the general lack of melilite among hibonite-, spinel-bearing inclusions is kinetic inhibition of melilite condensation relative to spinel. Because of similarities between the crystal structures of hibonite and spinel, it should be easier for spinel than for melilite to form from hibonite.
Price Discrimination in the Food Industry: A Competitive Stimulant or Tranquilizer?

HE food industry has played a central role in the establishment, evolution, and interpretation of the Robinson-Patman Act. In 1934 the Federal Trade Commission (FTC) chain store investigation found that discriminatory price concessions given chains by food processors were in part responsible for the chains' competitive advantage [2, p. 155]. This landmark investigation of the food industry contributed materially to the ultimate passage of the Robinson-Patman Act in 1936 [14, p. 171]. Through time, discriminatory practices of food processors and the exacting power position of chains have continued to play a central role in the interpretation and enforcement of the Robinson-Patman Act.1 The National Commission on Food Marketing found that from 1951 to 1964 the FTC had made 1,792 formal investigations of discriminatory preferences affecting retail food distribution [14, p. 172]. Between June 1950 and June 1964, the FTC filed 53 complaints against food marketing concerns charging illegal discrimination [14, p. 176].2 The purpose of this paper is to provide insight into the interpretation of what constitutes discriminatory pricing practices and to examine the motives for discriminatory behavior in the food industry. It is hoped that the article will provide a basis for placing the concept of price discrimination in a broader context than is traditional in economic theory.
An NP-Hard Open Shop Scheduling Problem with Polynomial Average Time Complexity

While the worst-case complexity of most scheduling problems is known, the average-case complexity has not been studied. This paper examines the average-case complexity of the following NP-hard open shop scheduling problem: minimize the makespan on two machines with two distinct release dates. We present a deterministic algorithm where the average-case complexity is polynomial in the number of jobs when the known deterministic processing times of jobs are generated for each machine as nonnegative i.i.d. random variables from certain classes of distributions. The classes of distributions include all bounded distributions and all distributions with exponential tails. Linear time algorithms for two variations of the two-machine open shop scheduling problem are also obtained. These problems are minimizing the weighted sum of machine completion times, and minimizing the makespan when one machine is initially unavailable for processing. A variation of the second problem can be used to solve the problem of minimizing the makespan when there is a rolling horizon.
Compound-specific carbon and hydrogen isotope analysis of sub-parts per billion level waterborne petroleum hydrocarbons.

Compound-specific carbon and hydrogen isotope analysis (CSCIA and CSHIA) has been increasingly used to study the source, transport, and bioremediation of organic contaminants such as petroleum hydrocarbons. In natural aquatic systems, dissolved contaminants represent the bioavailable fraction that generally is of the greatest toxicological significance. However, determining the isotopic ratios of waterborne hydrophobic contaminants in natural waters is very challenging because of their extremely low concentrations (often at sub-parts ber billion, or even lower). To acquire sufficient quantities of polycyclic aromatic hydrocarbons with 10 ng/L concentration for CSHIA, more than 1000 L of water must be extracted. Conventional liquid/liquid or solid-phase extraction is not suitable for such large volume extractions. We have developed a new approach that is capable of efficiently sampling sub-parts per billion level waterborne petroleum hydrocarbons for CSIA. We use semipermeable membrane devices (SPMDs) to a...
Localized opto-mechanical control of protein adsorption onto carbon nanotubes.

Chemical reactions can be described by an energy diagram along a reaction coordinate in which an activation barrier limits the rate at which reactants can be transformed into products. This reaction impedance can be overcome by reducing the magnitude of the barrier through the use of catalysis, increasing the thermal energy of the system, or through macroscopic mechanical processes. Here, we demonstrate direct molecular-scale control of a reaction through the precise application of opto-mechanical work. The method uses optical gradient forces generated in the evanescent field surrounding hybrid photonic-plasmonic structures to drive an otherwise unlikely adsorption reaction between proteins and carbon nanotubes. The adsorption of immunoglobulins on carbon nanotubes is used as a model reaction and investigated with an extended DLVO theory. The technique is also used to force a Forster resonance energy transfer between fluorophores on mismatched immunoglobulin proteins and is expected to lead to novel forms of chemical synthesis.
Induction of DNA double-strand breaks by X-rays in a radiosensitive strain of the yeast Saccharomyces cerevisiae

Abstract Sedimentation profiles for chromosomal DNA from unirradiated and X-irradiated yeast cells of wild type and rad 52 strains are presented. These profiles indicate that, whereas wild type strains rejoin DNA double-strand breaks, rad 52 strains apparently do not. These data suggest that the rad 52 mutant lacks a repair system for X-ray induced damage and are consistent with the proposal that an unrepaired chromosome break leads to reproductive cell death.
Heart-Specific Ablation of Prkar1a Causes Failure of Heart Development and Myxomagenesis

Background— Protein kinase A signaling has long been known to play an important role in cardiac function. Dysregulation of the protein kinase A system, caused by mutation of the protein kinase A regulatory subunit gene PRKAR1A, causes the inherited tumor syndrome Carney complex, which includes cardiac myxomas as one of its cardinal features. Mouse models of this genetic defect have been unsatisfactory because homozygote null animals die early in development and heterozygotes do not exhibit a cardiac phenotype. Methods and Results— To study the cardiac-specific effects resulting from complete loss of Prkar1a, we used cre-lox technology to generate mice lacking this protein specifically in cardiomyocytes. Conditional knockout mice died at day 11.5 to 12.5 of embryogenesis with thin-walled, dilated hearts. These hearts showed elevated protein kinase A activity and decreased cardiomyocyte proliferation before demise. Analysis of the expression of transcription factors required for cardiogenesis revealed downr...
Nanogeochemistry: Nanostructures, emergent properties and their control on geochemical reactions and mass transfers

Abstract Nanogeochemistry—a newly emerging research field—attempts to understand geochemical reactions and mass transfers at nanometer scales, especially with regards to the formation of nanostructures in geochemical systems, emergent properties of these structures, and their controls on geochemical processes. The research also includes use of nanotechnology to design new materials and engineering approaches for effective natural resource extraction and environmental management. At the core of this new research field is the concept that, as the size of a material is reduced to nanometers, novel physical or chemical properties of the material may emerge that can be drastically different from those of the corresponding bulk phase and the material properties then become size-dependent. Nanostructures, which frequently occur in geologic materials, may directly control mineral phase stability, mineral–water interface chemistry, geochemical reaction kinetics, geo-fluid migration and transport, and even global biogeochemical cycles as a whole. This paper aims to provide a comprehensive review of recent progress in nanogeochemical research. The review is focused on two general types of nanostructures—nano solid phases and nanopores (nanofluids)—with an emphasis on the occurrence of each nanostructure in natural environments, the associated emergent properties, and the potential geochemical implications. Stemming from an increasing interest in shale gas research, a special discussion is provided on gas/oil disposition and migration in unconventional low-permeability reservoirs, wherein shale is treated as a nanocomposite material. Nanogeochemistry is a relatively young research field, and much remains to be explored. There is an urgent need for systematically characterizing specific nanostructures over the whole nanometer-size range and developing a general theoretical framework for data analysis and synthesis. There is also a need for developing experimental and modeling techniques to extrapolate the knowledge obtained from simple model systems to complex natural systems.
Software for differential systems and applications involving macroscopic kinetics

Abstract A substantial amount of well tested software is readily available to the scientific community at low cost or no cost. Here, we describe some of this software and give some examples of problems which illustrate its use in model problems involving maroscopic kinetics.
Properties of the Esterase Produced by Mucor miehei to Develop Flavor in Dairy Products

Abstract The development of Italian cheese flavor is attributed in large part to the action of animal pregastric esterases added to the milk prior to coagulation. Comparable flavor in Fontina and Romano cheese can be developed with an esterase preparation derived from Mucor miehei . The unique ability of this esterase to replace the animal-derived enzymes prompted a study of its properties. Esterase and microbial rennet are produced by Mucor miehei in the same fermentation. The enzymes are separated by filtration at pH 5.0. The insoluble esterase then is recovered by extraction of the filter cake at pH 10.5. The enzyme has a pH optimum of 7.0 on tributyrin, has a temperature optimum of 50C, and is stable over the pH range of 4.0 to 10.0 and up to 55C at pH 5.3. The enzyme will hydrolyze a number of synthetic triglycerides, with optimum activity on tributyrin and trioctanoin. Higher molecular weight fatty acid containing triglycerides are hydrolyzed less readily. Sorbitol esters of fatty acids also are attacked. The esterase will hydrolyze a number of animal fats and vegetable oils and is relatively unaffected by high concentrations of various salts, ethylene diamine tetraacetate, or sulfhydryl inhibitors.
Compilation of π − p Data at 4 GeV/ c : Backward Resonance Production and π π Scattering

In ${\ensuremath{\pi}}^{\ensuremath{-}}p$ single-pion-production reactions near 4 GeV/c, we observe several interesting features. Backward ${\ensuremath{\rho}}^{0}$ production is seen to occur with $\frac{d\ensuremath{\sigma}}{\mathrm{du}}=63\ifmmode\pm\else\textpm\fi{}21$ \ensuremath{\mu}b/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ at 180\ifmmode^\circ\else\textdegree\fi{}. Backward ${\ensuremath{\rho}}^{\ensuremath{-}}$ production is less prominent. We see evidence for production at small $u$ of ${N}^{*0}$ ($p{\ensuremath{\pi}}^{\ensuremath{-}}$ near 1700 MeV) and ${\ensuremath{\Delta}}^{\ensuremath{-}}$ ($n{\ensuremath{\pi}}^{\ensuremath{-}}$ at 1236 MeV), and possible evidence for other $n{\ensuremath{\pi}}^{\ensuremath{-}}$ structure at about 1800 MeV. The density-matrix elements for peripheral ${\ensuremath{\rho}}^{0}$ production are presented in the Jackson and in the helicity frame. The ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ elastic cross section is obtained by extrapolation of the data to the mass shell. The $S$-wave $\ensuremath{\pi}\ensuremath{\pi}$ phase shifts are calculated by two methods and compared with previous results. We find evidence in the dipion decay angular distribution for the ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ decay mode of the ${S}^{*}(1070)$.
Estimating Biomass in Coastal Baccharis pilularis Dominated Plant Communities

Communities dominated by Baccharis pilularis (coyote brush) are expanding in coastal California altering fuel load on a landscape scale, yet there is no standard method for estimating biomass in this vegetation type. In an attempt to develop a non-destructive field method for estimating biomass in Baccharis-dominated communities, we compared three indirect measures including crown canopy height, basal stem diameter, and leaf area index (LAI) estimated using hemispherical photography. Data were collected on 90 one square meter randomly selected plots in Point Reyes National Seashore and Golden Gate National Recreation Area. Linear regression analysis was used to determine the effectiveness of each predictor. The best single predictor of biomass was crown canopy height with an adjusted R2 of 0.46 for both sites combined. The linear regression equation developed for biomass versus height predicted 3930 grams per meter in height ± 430 grams for each square meter on these sites found. Basal stem diameter was determined to be a weak predictor in this vegetation type (R2 = 0.17). Estimated LAI had no predictive value. Multiple linear regressions with biomass versus height and basal area was also tested resulting in a slightly stronger model with an adjusted R2 of 0.48. Because of its predictive value, and ease of implementation, we suggest the use of crown canopy height as the most efficient biomass predictor in this vegetation type.
Welfare benefits and birth decisions of never-married women

For some time now, the out-of-wedlock birthrate has been increasing rapidly in the United States. This has prompted several states to propose (and in some cases, enact) legislation to deny access to higher AFDC benefits for families in which the mother gives birth while receiving AFDC. The authors investigate whether AFDC benefit levels are systematically related to the family-size decisions of never-married women. Using a bivariate probit model with state and time fixed effects, applied to Current Population Survey data for the years 1980–1988, it is found that the basic benefit level for a family of two (one adult and one child) and the incremental benefit for a second child positively affects the family size decisions of black and Hispanic women, but not of white women. The effects are concentrated among high school dropouts (no effects are found for high school graduates). The authors conclude that rather than to uniformly deny benefits to all AFDC women that bear children, a better targeted policy might be to alter the AFDC benefit structure in such a way as to encourage single mothers to complete high school. However, being a high school dropout might be a proxy for some other underlying characteristic of the woman, and encouraging women to complete high school who otherwise would not might have no effect whatsoever on nonmarital births.
Antenna diversity using single antenna in robot communication

This study proposes to exploit multipath signals by repositioning a robot relay node within a quarter to one wavelength from its current position to improve signal quality. By mobilizing the communication node we offer a complementary solution to antenna diversity in environments where antenna diversity cannot be employed. The signal strength characterization is performed over a small area to study the impact of relocation of the node by a quarter to one wavelength. A new conjugate gradient search algorithm for exploiting combined multipath fading is proposed to improve signal quality between a mobile station and a set of other stations - mobile or fixed.
The principle of complementary energy in nonlinear elasticity

Abstract It is the purpose of this report to examine the basic principles on which the method of “Minimum Complementary Energy” is based and to study the use of this principle in the analysis of problems on nonlinear elasticity. This report is the first phase of an investigation of possible methods of solution of problems involving elastic structures that undergo large deflections, creep, and thermal stresses.
On the existence of equilibrium states of an elastic beam on a nonlinear foundation

This paper concerns the existence and uniqueness of equilibrium states of a beam-column with hinged ends which is acted upon by axial compression and lateral forces and is in contact with a semi-infinite medium acting as a foundation. The problem is formulated as a fourth-order nonlinear boundary value problem in which the source of the nonlinearity comes from the lateral constraint (the foundation). Treating the equation of equilibrium as a nonlinear eigenvalue problem we prove the existence of a pair of eigenvalue/eigenfunction for each arbitrary prescribed energy level. Treating the equilibrium equation as a nonlinear boundary value problem we prove the existence and uniqueness of solution for a certain range of the acting axial compression force.
The Role of Prior Expectancy and Group Discussion in the Attribution of Attitudes

Abstract This study sought to understand conditions under which group discussion enhances and weakens individual bias in the attribution of attitudes. Subjects were given congruent, incongruent, or irrelevant prior expectancy information about the attitude of an essay writer who was assigned to either support or oppose legalizing marijuana. Subjects estimated the essay writer′s actual attitude on legalized marijuana before and after engaging in a three-person group discussion. Discussion attenuated the dispositional bias when members were given an irrelevant prior expectancy. With an incongruent expectancy, the bias was reversed after discussion. However, with a congruent prior expectancy, group discussion did not affect the strong correspondent inference. The features of discussion content that were related to these shifts are consistent with recent theories of attribution.
Rescattering of photodetached electrons from a polar molecule in a static electric field: Spatial distribution

We investigate the spatial distribution of electrons photodetached from a polar molecular anion in an external static electric field. The large electron-molecule scattering amplitude strongly enhances the rescattering effect. This opens an opportunity for experimental investigation of collisions of ultraslow electrons (in the energy range below 0.1 meV) by polar molecules.
Pleomorphic xanthoastrocytoma in children and adolescents

Background Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor occurring primarily in children and young adults. The superficial location of the tumor facilitates gross total resection (GTR) thus conferring a relatively favorable outcome with a reported 10-year overall survival (OS) of 70%. Procedure A retrospective case analysis of children and adolescents diagnosed and treated with PXA in our institution between January 1980 and March 2009 and a literature review. Results 85.7% of our patients with a GTR were recurrence free. Only one of seven patients with less than a GTR did not recur and median time to recurrence was under 1 year in patients who did not have a GTR. Two of three patients with anaplastic features or malignant transformation at initial presentation progressed. Five-year OS and recurrence free survival (RFS) was 85.7% and 49%, respectively. Conclusions GTR is the preferred treatment modality for PXA. Anaplastic features, though uncommon at initial presentation, confer a less favorable outcome. The role of adjuvant therapy with primary and recurrent anaplastic PXAs, especially when complete resection is not feasible, warrants further study. Pediatr Blood Cancer. 2010;55:290–294. © 2010 Wiley–Liss, Inc.