cssi/SciSciGPT-SciSciNet huggingface dataset:
LIQUID-SOLID PARTICLE SLURRY EROSION OF STEELS

Abstract The erosion behavior of candidate steel alloys for liquid-solid particle slurry service in coal conversion equipment was determined over a range of testing conditions. Higher solids loading and larger particles in the coal-kerosene slurries resulted in greater erosion. The greater the boundary lubrication of the carrier liquid, the lower the erosivity of the slurry. Low elevated temperatures can cause a decrease or an increase in the erosivity of the slurry, depending on the nature of the liquid carrier, the alloy tested and the test temperature. The mechanism of erosion was determined to be of a platelet formation type, similar to that observed in gas-solid particle stream erosion of ductile metals. However, the cold-worked zone caused by the striking particles is located at the surface in liquid-solid particle erosion while it is beneath the surface in gas-solid particle erosion. The relative erosion resistance of the carbon, low alloy, chromium bearing and austenitic steels tested could not be readily related to their composition, morphology or common mechanical properties. A possible relation to the strain-hardening behavior of the alloys was indicated.
A Brief Survey of PageRank Algorithms

We examine several PageRank approximation algorithms. Quantitative analyses are provided to illustrate the extraordinary effectiveness of the PageRank computation.
Ion Acoustic Waves in a Collisional Plasma

The damping of the ion acoustic waves by Coulomb collisions is studied by using the Fokker-Planck equation of Rosenbluth et al. for both the species constituting the plasma, namely, the electrons and the ions. In a plasma with weak collisions and in the absence of any external field, one finds that irrespective of the ratio $T$ of the ion temperature to the electron temperature, the characteristic frequency gets affected only by the electron-ion collisions. However, as far as the collisional damping is concerned, both the ion-ion and the electron-ion collisions play a somewhat equally important role; the electron-electron and the ion-electron contributions are negligible compared to the other two. The damping increases with increase in the collision frequency but decreases with increase in $T$.
Computational study of ketosteroid isomerase: insights from molecular dynamics simulation of enzyme bound substrate and intermediate.

Δ5-3-Ketosteroid Isomerase (KSI) catalyzes the isomerization of 5,6-unsaturated ketosteroids to their 4,5-unsaturated isomers at a rate approaching the diffusion limit. The isomerization reaction follows a two-step general acid−base mechanism starting with Asp38-CO2- mediated proton abstraction from a sp3-hybridized carbon atom, α to carbonyl group, providing a dienolate intermediate. In the second step, Asp38-CO2H protonates the C6 of the intermediate providing a 4,5-unsaturated ketosteroid. The details of the mechanism have been highly controversial despite several experimental and computational studies of this enzyme. The general acid−base catalysis has been proposed to involve either a catalytic diad or a cooperative hydrogen bond mechanism. In this paper, we report our results from the 1.5 nanosecond molecular dynamics (MD) simulation of enzyme bound natural substrate (E·S) and enzyme bound intermediate (E·In) solvated in a TIP3P water box. The final coordinates from our MD simulation strongly suppor...
A quantile regression analysis of the rebound effect: Evidence from the 2009 National Household Transportation Survey in the United States

Abstract This paper applies quantile regression method to measure the rebound effect and differentiate it with respect to demand for mobility using the 2009 National Household Transportation Survey (NHTS). The quantile regression results indicate that the rebound effect varies with the distribution of vehicle miles traveled (VMT), ranging between 0.11 and 0.19. Road network density and population density also play an important role in determining travel demand. Regression results indicate that travelers living in areas with higher road network density travel more miles although this positive impact consistently declines along the VMT distribution. Travelers living in areas with population density of at most 3000 persons per square miles travel more miles than those living in higher density areas. The quantile regression results also indicate that the impact of income is positive but declines consistently along the VMT distribution.
Metabolic and hormonal effects of feeding chickens thyroxine and diets containing varied calorie to protein ratios

Abstract Indian River male broiler chickens, growing from 7 to 28 d of age, were fed diets containing energy to protein ratios from 43 to 106 MJ/kg of protein + 0 or 1 mg/kg thyroxine (T 4 ) to study both the energetic and metabolic costs of lipogenesis. Denovo lipid synthesis was determined in the presence and absence of ouabain (ATPase inhibitor) to estimate the energetic costs of ion pumping in explants synthesizing lipid. Growth and feed consumption increased (P 4 depressed plasma growth hormone and insulin-like growth factor-I. A large calorie-to-protein ratio increased (P + /K + transport. In addition, plasma thyroid hormone ratios were changed by both energy to protein ratios and T 4 .
ALVIN GOULDNER AND THE SOCIOLOGY OF IDEAS: Lessons from Enter Plato

Alvin Gouldner's 1965 book Enter Plato is one of the most important contributions ever made to the sociology of ideas. Overshadowed soon after its publication, however, by Gouldner's more controversial work, The Coming Crisis of Western Sociology, the earlier book has suffered neglect. In an effort to correct this situation, we situate Enter Plato against the backdrop of other mid-twentieth-century works in the sociology of knowledge and related areas, arguing that Gouldner's study was one of the first sustained responses to Robert K. Merton's call for a sociology of knowledge that would steer a middle course between the abstract, speculative tendencies of the field's European founders and the relatively atheoretical contributions of their American counterparts. We build on this interpretation to offer a contemporary sociological appraisal of Enter Plato, considering its positive and negative lessons for sociologists of knowledge and ideas at the present time.
Reification of instructional materials as part of the process of developing problem‐based practices in mathematics education

This teacher development study closely examined a teacher's practice for the purpose of understanding how she selected and implemented instructional materials, and correspondingly how these processes changed as she developed her problem‐based practice throughout a school year. Data sources included over 20 hours of planning and analysis meetings with the teacher and 27 video‐taped lessons with discussions before and after each lesson. Through qualitative analysis we examined the data for: students' cognitive demand for curricular materials the teacher selected and implemented; teacher's beliefs and practices for students' engagement in mathematical thinking; and teacher's and students' communication about mathematics during instruction. We found that the teacher shifted her views and use of instructional materials as she changed her practice towards more problem‐based approaches. The teacher moved from closely following her traditional, district‐adopted textbook to selecting problem‐based tasks from outsi...
Effect of furosemide on unidirectional fluxes of sodium and chloride across the skin of the frog, Rana pipiens

1. The diuretic furosemide, when added to the outside solution at a concentration of 5-10-4 M, increases the electrical potential difference (PD) across the isolated frog skin, but the short-circuit current (Isc) is unchanged. Lower concentrations had no significant effect on these electrical parameters. 2. When SO42- or NO3- are substituted for Cl- in the Ringer's solution furosemide has no effect on the PD or Isc. 3. Simultaneous unidirectional fluxes of Na+ and Cl- show that furosemide (5-10-4 M outside) reduces both the influx and outflux of Cl-, while the Na+ fluxes are not altered. 4. Furosemide (5-10-4 M) on the corium side of the frog skin had no significant effect on either PD, Isc or undirectional fluxes of Cl-. 5. It is suggested that furosemide reduces passive Cl- transfer, possibly by interacting with the Cl-/Cl- exchange diffusion mechanism which has been observed in this tissue. These observations further suggest that perhaps the diuretic action of furosemide may be mediated by such an effect on passive Cl- permeability which is linked to the active Cl- transport mechanism in the renal tubule.
The impact of national culture on negotiating behaviors across borders

Recent declines in American competitiveness and the increasing globalization of American business underscore the importance of one's culturally-based negotiating ability in international business transactions. This paper examines the impact of cultural dimensions on negotiating effectiveness on three levels: the role of a single dimension of culture, the interactive effects between multiple dimensions of culture, and the degree of cultural compatibility between negotiating parties. Two existing models of negotiation are integrated, outlining the critical importance of culture in each stage of effective international business negotiations. The integrated model is then applied to the cultures of eleven nations. Propositions and suggestions for future research are provided.
Computed tomography in the diagnosis of intracranial vascular malformations.

Abstract Thirty-one patients with intracranial vascular malformations were studied by computed tomography (CT), including arteriovenous malformations (AVM) (24), Sturge-Weber syndrome (3), vein of Galen malformation (2) and venous angioma (2). Non-contrast CT showed abnormalities in 27 cases consistent with hemorrhage, calcification, low-density cystic spaces, and post-contrast scan showed abnormal enhancement in 25 of 31 cases. In 14 of 25 cases, the enhancement pattern showed evidence of abnormal vessels to indicate the presence of vascular malformation prior to angiography, whereas in 11 cases the enhancement pattern was not sufficiently characteristic.
The presence of a hydrogen bond between asparagine 485 and the pi system of FAD modulates the redox potential in the reaction catalyzed by cholesterol oxidase.

Cholesterol oxidase catalyzes the oxidation and isomerization of cholesterol to cholest-4-en-3-one. An asparagine residue (Asn485) at the active site is believed to play an important role in catalysis. To test the precise role of Asn485, we mutated it to a leucine and carried out kinetic and crystallographic studies. Steady-state kinetic analysis revealed a 1300-fold decrease in the oxidation k(cat)/K(m) for the mutant enzyme whereas the k(cat)/K(m) for isomerization is only 60-fold slower. The primary kinetic isotope effect in the mutant-catalyzed reaction indicates that 3alpha-H transfer remains the rate-determining step. Measurement of the reduction potentials for the wild-type and N485L enzymes reveals a 76 mV decrease in the reduction potential of the FAD for the mutant enzyme relative to wild type. The crystal structure of the mutant, determined to 1.5 A resolution, reveals a repositioning of the side chain of Met122 near Leu485 to form a hydrophobic pocket. Furthermore, the movement of Met122 facilitates the binding of an additional water molecule, possibly mimicking the position of the equatorial hydroxyl group of the steroid substrate. The wild-type enzyme shows a novel N-H...pi interaction between the side chain of Asn485 and the pyrimidine ring of the cofactor. The loss of this interaction in the N485L mutant destabilizes the reduced flavin and accounts for the decreased reduction potential and rate of oxidation. Thus, the observed structural rearrangement of residues at the active site, as well as the kinetic data and thermodynamic data for the mutant, suggests that Asn485 is important for creating an electrostatic potential around the FAD cofactor enhancing the oxidation reaction.
Reduction of oxygen in lithium-potassium carbonate melt

Abstract The oxygen reduction reaction on smooth gold electrodes on Li/K (53: 47 at.%) carbonate melt has been examined in the temperature range 700–800°C. As in previous work on the Na/K melt [2], two chemically produced species (O22− O2−) are reduced in parallel steps. The waves for the reduction of these species are close together in this melt, as distinct from those in the Na/K eutectic [2]. Exchange currents are somewhat higher than in the Na/K melt. Again, neutralization of the O2− ion by CO2 in rather slow, and may be rate-determining in porous electrodes.
The impact of cations on nucleus density during copper electrodeposition

Abstract High nucleus density is among the most important factors in determining the success of the direct-copper-electrodeposition technique. A group of inorganic species including potassium sulfate (K2SO4), sodium sulfate (Na2SO4), magnesium sulfate (MgSO4), and copper sulfate (CuSO4) were investigated in terms of their impact on copper nucleus density during galvanostatic electrodeposition of copper onto foreign substrates. Newly formed copper nuclei on the substrate were observed using scanning electron microscopy (SEM) and then manually counted to obtain nucleus density data. Results show that in the presence of K2SO4, copper nucleus density can be increased by a factor of up to 7, while Na2SO4 may lead to at least double increase of nucleus density. Electroanalysis indicates that the overpotential increase as a result of adding relevant sulfate salts may account for the increased nucleus density.
Green Fluorescent Protein as a Tissue Marker in Transgenic Maize Seed

ABSTRACT Seed tissues (endosperm, embryo, and pericarp) are often separated into tissue-enriched fractions by wet- or dry-milling methods for use in food, feed, and industrial products. Seed tissue markers that are sensitive and readily quantifiable would be useful to optimize fractionation processes. To meet this need for tissue markers, we set out to produce and characterize different transgenic maize lines, each containing green fluorescent protein (GFP) in either endosperm or embryo. We examined mRNA transcripts using expressed sequence tag (EST) profiles of several major seed proteins and selected several with strong seed tissue preferences. Stably transformed maize lines were produced, and visual observation of fluorescence confirmed the presence of GFP in the desired tissues. To establish the utility of this grain for evaluating the effectiveness or separation efficiencies of fractionation processes, transgenic kernels were hand-dissected into pericarp, endosperm, and embryo fractions and the GFP c...
The diagnosticity of individual data for model selection: Comparing signal-detection models of recognition memory

We tested whether the unequal-variance signal-detection (UVSD) and dual-process signal-detection (DPSD) models of recognition memory mimic the behavior of each other when applied to individual data. Replicating previous results, there was no mimicry for an analysis that fit each individual, summed the goodness-of-fit values over individuals, and compared the two sums (i.e., a single model selection). However, when the models were compared separately for each individual (i.e., multiple model selections), mimicry was substantial. To quantify the diagnosticity of the individual data, we used mimicry to calculate the probability of making a model selection error for each individual. For nondiagnostic data (high model selection error), the results were compatible with equal-variance signal-detection theory. Although neither model was justified in this situation, a forced-choice between the UVSD and DPSD models favored the DPSD model for being less flexible. For diagnostic data (low model selection error), the UVSD model was selected more often.
Morphology of TiSi2 and ZrSi2 on Si(100) and (111) surfaces

The morphologies of ZrSi2 on Si(111) and TiSi2 on Si(111) and (100) have been investigated, and the results compared and contrasted. Films were prepared by UHV deposition of Ti or Zr onto clean, reconstructed Si(100) or (111) substrates, and reacted by in situ annealing. The sheet resistivity of the ZrSi2 was measured and found to be 33-42 μΩ-cm. The morphologies were examined by transmission and scanning electron microscopy. In particular, the islanding properties were studied; both the temperature of the onset of islanding and the island characteristics were measured. The surface and interface energies have been determined from the contact angles of the silicide islands, according to a solid-state capillarity model. The system of ZrSi2 on Si(111) was found to have surface and interface energies lower than those of the system of TiSi2 on Si(100), but higher than those of the system TiSi2 on Si(111). ZrSi2 on Si(111) was found to island at a higher temperature than TiSi2 on either substrate, a result attributed to kinetic effects. Areal coverage of the islands was measured, and the results were consistent with the solid-state capillarity model. For both TiSi2 and ZrSi2, increasing faceted structure was observed with increasing anneal temperature. Preferred faceting planes were found to be of Si(111) and (100) type for TiSi2 islands and of Si(111) type for ZrSi2. Faceted islands were apparently epitaxial. As the solid-state capillarity model does not directly apply to islands with a faceted structure, an observation of the percentage of faceted islands produced by different annealing temperatures was used to suggest the processing conditions in which the model is applicable.
Nonurban Habitat Use of Florida Burrowing Owls: Identifying Areas of Conservation Importance

Abstract Statewide distribution and habitat use of the Florida Burrowing Owl (Athene cunicularia floridana), currently state-listed as a “Species of Special Concern,” is not well-understood, particularly in remote, nonurban areas. Its status as a protected species is currently being reevaluated and information is needed to help state wildlife managers better understand habitat usage in nonurban areas. To help address this need, we visited Burrowing Owl sites from historical databases to verify and update them while also documenting new locations. We quantified land cover within empirically-derived distances around burrows with confirmed or probable breeding activity, then compared observed and available proportions of habitat, calculated selection indices, and determined selection/avoidance for each land-cover class. These empirical results were used in combination with literature review and field observations to select land-cover criteria for suitable habitat. The final results appear to correlate well w...
Distinguishing anxiety and depression with field survey data

Data on self-reported symptoms collected in the East Baltimore site of the Epidemiologic Catchment Area Program are analysed in parallel fashion for the two syndromes of anxiety and depression. Patterns of relationships of anxiety and depression to sociodemographic factors, prior psychopathology, and life events fail markedly to distinguish the two syndromes.
Nucleotide sequence and molecular genetic analysis of the vaccinia virus HindIII N/M region encoding the genes responsible for resistance to α-Amanitin

Abstract The genomic location of the gene(s) which provides vaccinia virus (VV) α-amanitin-resistant mutants with a drug-resistant phenotype have been mapped to the Hind III N/M region of the genome by the use of marker rescue techniques [ E. C. Villarreal and D. E. Hruby (1986) J. Virol. 57,65–701. Nucleotide sequencing of a 2356-bp Hind III- Sau 3A fragment of the vaccinia virus genome encompassing this region reveals the presence of two complete leftward-reading open reading frames (ORFs, N2 and M1) and two incomplete ORFs (N1 and M2). By computer analysis the N2 and M1 ORFs would be predicted to encode soluble VV polypeptides with molecular weights of approximately 20 and 48 kDa, respectively. The N2 and M1 ORFs have extremely A-T-rich 5′-proximal sequences, consistent with previous data regarding the location and A-T-richness of viral early promoters. Likewise, the consensus signal believed to be involved in terminating VV early gene transcription, TTTTTNT, was evident at the 3′-boundary of both the N2 and M1 ORFs suggesting that these genes may be VV early genes. The in vivo transcriptional activity, orientation, and limits of these putative transcriptional units were investigated by Northern blot, nuclease S1, and primer extension analysis. Both N2- and M1-specific transcripts were detected in the cytoplasm of VV-infected cells, suggesting that these loci are bonafide viral genes. Time-course nuclease S1 experiments revealed that the N2 gene was transcribed exclusively prior to VV DNA replication. In contrast, the M1 gene was transcribed throughout infection, although different start sites were used at early versus late times postinfection. These results are discussed in relation to the drug-resistant phenotype and future experiments to identify the viral gene product responsible.
Stabilizing Compacted Clay against Chemical Attack

Concentrated organic chemicals have been shown to cause large increases in the hydraulic conductivity of compacted clay. Mechanical and chemical methods of stabilizing four different types of compacted clay against chemical attack are investigated. Mechanical stabilization using large compactive effort (modified Proctor compaction) or application of a compressive stress ≥\N 10 psi (70 kPa) is found to render a compacted clay invulnerable to attack by concentrated organic chemicals under laboratory-test conditions. Attapulgite, a clay mineral having little electrical charge, was found to be relatively unaffected (compared to more common clay minerals such as kaolinite, illite, and smectite) by concentrated organic chemicals. Addition of approximately 7% (by weight) of lime, portland cement, or lime plus sodium silicate greatly improved the ability of compacted clay to resist attack by concentrated organic chemicals; in some cases the amended soils were less permeable to concentrated organic chemicals than the unamended soils were to water.
Colouterine fistula and pyometrium treated with percutaneous drainage: A case report

Percutaneous drainage of intraabdominal abscesses has become a routine procedure for preoperative confirmation of diagnosis and patient stabilization, and often provides definitive therapy. Diverticulitis is a frequent cause of pericolonic abscess but rarely results in colouterine fistula and pyometrium. We describe the first reported percutaneous drainage of such a case of pyometrium.
Leveraging the electronic health record to implement genomic medicine

The use of whole-genome/exome sequence in select clinical settings to improve health and prevent disease, considered to be improbable a few years ago, is now approaching reality. However, the advent of “next-generation” sequencing technologies presents a paradox: the prospect of managing ever-increasing amounts of genomic data is in itself an obstacle to the vision of genome-informed health care. Here, we present our view that the solution to integrating these data into the flow of health care lies in a genome-enabled electronic health record (EHR).1 Such EHRs would receive, store, and present complex genomic information for clinical use, incorporate clinical decision support to help providers practice individualized medicine, and provide links to relevant knowledge resources. Although adoption of EHRs is increasing, the majority of EHR systems are not configured to deal with genetic data,2 particularly data from whole-genome/exome sequences. This article summarizes the challenges in implementing genomic medicine using the EHR and discusses the role various stakeholders might play in addressing these challenges.
Toxic Effects of 7,12-Dimethylbenz(a)-anthracene in New-born and Adult Swiss Mice

DURING previous investigations of chemical carcinogenesis, we repeatedly found that new-born mice injected once with 7,12-dimethylbenz(a)anthracene (DMBA) died at a certain time after the treatment. On this basis we decided to investigate, in an exact manner, the toxicity of a carcinogenic dose of DMBA in new-born mice. Furthermore, we included in this investigation an adult group of mice in order to compare the toxicity rate of this carcinogen in two age groups of animals.
Gastric and Esophageal Emergencies

The pathophysiology of esophageal and gastric disorders is complicated and broad and includes iatrogenic, structural, inflammatory, neuromuscular, neoplastic, and infectious causes. Symptoms can be nonspecific and are often initially attributed to cardiac or respiratory causes. These disorders have both acute and chronic presentations that require different approaches to diagnosis and management. A thorough history and physical examination enable emergency physicians to initiate evaluation of gastroesophageal disorders. Complete evaluation often requires a combination of emergent screening to rule out life-threatening problems as well as coordinated outpatient testing.
Why Americans Hate Politics

One of our shrewdest political observers traces thirty years of volatile political history and finds that on point after point, liberals and conservatives are framing issues as a series of "false choices," making it impossible for politicians to solve problems, and alienating voters in the process.
‘We Have to Bring Something Different to this Place’: Principled and Pragmatic Nonviolence Among Accompaniment Workers

Many scholars of social movements and nonviolence frame the salient ideological divisions among nonviolent activists as a dichotomy or a continuum between principled and pragmatic nonviolence. Yet, there is a notable lack of empirical analyses on the prevalence of these nonviolent orientations among activists, and how they might contribute to tactical choices and shape emotional fields of interaction with opponents. Building from fieldwork and interviews (N = 25), this case study analyzes the nonviolent performances of Christian Peacemaker Teams and the International Solidarity Movement in Israel–Palestine. It is contended that international accompaniment workers perform nonviolence in starkly divergent ways depending on their personal commitments to either principled or pragmatic nonviolence, as well as organizational norms on this dimension. It is proposed that linking ‘tragic’ and ‘comic’ dramaturgical styles to the performance of nonviolent activism offers a route for specifying the mechanisms of prag...
AGU's 50,000‐member‐strong Union

AGU membership reached 50,000 in September 2007. Membership has doubled since the early 1990s. Membership grew moderately through the late 1990s, reached 40,000 members in 2001, and grew at a rate of 5% or more for each of the past 3 years. The size of AGU membership is not the only factor reinforcing the role of AGU as a leader in the increasingly interdisciplinary global endeavor that encompasses the Earth and space sciences. Diversity is another key factor. AGU members hail from 137 different countries. Members residing outside North America now represent more than 35% of the membership compared with 29% in 1995. There has also been a large increase in the number of women: 24% in 2007 compared with 13% in 1995. In addition, students now account for 20% of the membership.
Determination of penetratin secondary structure in live cells with Raman microscopy

Cell penetrating peptides (CPPs) have attracted recent interest as drug delivery tools, although the mechanisms by which CPPs are internalized by cells are not well-defined. Here, we report a new experimental approach for the detection and secondary structure determination of CPPs in live cells using Raman microscopy with heavy isotope labeling of the peptide. As a first demonstration of principle, penetratin, a 16-residue CPP derived from the Antennapedia homeodomain protein of Drosophila, was measured in single, living melanoma cells. Carbon-13 labeling of the Phe residue of penetratin was used to shift the intense aromatic ring-breathing vibrational mode from 1003 to 967 cm(-1), thereby enabling the peptide to be traced in cells. Difference spectroscopy and principal components analysis (PCA) were used independently to resolve the Raman spectrum of the peptide from the background cellular Raman signals. On the basis of the position of the amide I vibrational band in the Raman spectra, the secondary structure of the peptide was found to be mainly random coil and beta-strand in the cytoplasm, and possibly assembling as beta-sheets in the nucleus. The rapid entry and almost uniform cellular distribution of the peptide, as well as the lack of correlation between peptide and lipid Raman signatures, indicated that the mechanism of internalization under the conditions of study was probably nonendocytotic. This experimental approach can be used to study a wide variety of CPPs as well as other classes of peptides in living cells.
Treatment of Falciparum Malaria Caused by Strain Resistant to Quinine

Malaria caused by the Vietnam (Smith) strain of Plasmodium falciparum, isolated from a patient in the United States in 1969, is insusceptible to treatment with chloroquine phosphate, pyrimethamine, and chloroguanide hydrochloride. Radical cure has been obtained in some infected nonimmune patients by the use of quinine in courses of 8.1 gm (base) or more, but in other patients the infection has recrudesced following 22.7 gm (base) given over 14 days; in one patient despite demonstrated normal absorption the latter treatment failed to produce improvement, while addition of pyrimethamine in another did not clear parasitemia. Radical cure was achieved in an average time of 3 days in all of seven men receiving 18.9 gm (base) of quinine over 14 days (1.66 gm of quinine sulfate each day), with 1.0 gm of sulfalene given in four divided doses on the first day .
Gasification and synthesis gas fermentation: an alternative route to biofuel production.

Lignocellulosic biomass has been identified among the renewable energy sources to have the highest potential to minimize dependency on dwindling supplies of fossil fuels. Conversion of this biomass to biofuels by microorganisms through direct hydrolysis and fermentation can be challenging. Alternatively, biomass can be converted to synthesis gas (a mixture of CO, CO2, N2 and H2) through gasification and transformed to fuels using microbial catalysts that can convert the CO, H2 and CO2 to fuels such as ethanol, butanol and hydrogen. Biomass gasification–fermentation processing systems have shown promise and companies are now entering the marketplace for commercial-scale ethanol production from synthesis gas. Isolation of new organisms capable of higher product yield, as well as functional implementation of bioreactors that enhance gas solubility for microbial fermentation, make this technology an attractive option for reducing our dependency on fossil fuels.
Cefixime versus trimethoprim/sulfamethoxazole in treatment of patients with acute, uncomplicated lower urinary tract infections

One hundred six patients with acute, uncomplicated lower urinary tract infections participated in a randomized study that compared cefixime (one 400-mg tablet once daily) with trimethoprim (160 mg)/sulfamethoxazole (800 mg) (one tablet every 12 hours). Two cefixime recipients and 3 patients given trimethoprim/sulfamethoxazole had courses that were not evaluable for efficacy. At five to nine days post-therapy, 98 percent of the patients in each treatment group had clinical cure and bacteriologic eradication. At four to six weeks post-therapy, 87 percent (34/39) of the cefixime-treated patients and 83 percent (33/40) of those given trimethoprim/sulfamethoxazole had clinical cure and 90 percent (35/39) and 93 percent (37/40) of the patients in the respective treatment groups had bacteriologic eradication. Adverse clinical experiences or changes in the results of laboratory tests were few. Thus, a once-daily dose of cefixime was as safe and as effective as a twice-daily regimen of trimethoprim/sulfamethoxazole.
ATP-dependent chromatin remodeling: genetics, genomics and mechanisms

Macromolecular assemblies that regulate chromatin structure using the energy of ATP hydrolysis have critical roles in development, cancer, and stem cell biology. The ATPases of this family are encoded by 27 human genes and are usually associated with several other proteins that are stable, non-exchangeable subunits. One fundamental mechanism used by these complexes is thought to be the movement or exchange of nucleosomes to regulate transcription. However, recent genetic studies indicate that chromatin remodelers may also be involved in regulating other aspects of chromatin structure during many cellular processes. The SWI/SNF family in particular appears to have undergone a substantial change in subunit composition and mechanism coincident with the evolutionary advent of multicellularity and the appearance of linking histones. The differential usage of this greater diversity of mammalian BAF subunits is essential for the development of specific cell fates, including the progression from pluripotency to multipotency to committed neurons. Recent human genetic screens have revealed that BRG1, ARID1A, BAF155, and hSNF5 are frequently mutated in tumors, indicating that BAF complexes also play a critical role in the initiation or progression of cancer. The mechanistic bases underlying the genetic requirements for BAF and other chromatin remodelers in development and cancer are relatively unexplored and will be a focus of this review.
Temperature dependent formation of ZnO and Zn2SiO4 nanoparticles by ion implantation and thermal annealing

Abstract ZnO and Zn 2 SiO 4 nanoparticles have been synthesized by dual beam implantation of 45 keV ZnO − molecular ions and 15 keV O − ions into Si (100) substrates at room temperature to fluences of 1 × 10 17 and 2 × 10 17 ions/cm 2 , respectively. Implanted samples were annealed at different temperatures in a mixture of Ar and H 2 for 1 h. Rutherford backscattering spectrometry (RBS) was used to confirm the implanted ion fluences. The diffusion of Zn and O ions due to annealing was studied by using X-ray photoelectron spectroscopy (XPS). It was observed that at 700 °C annealing temperature, oxygen diffused into the substrate whereas Zn diffused in both directions; at 900 °C, oxygen diffused more into the substrate but the Zn diffused outward toward the surface. X-ray diffraction (XRD) was used to investigate the phase formation and particle sizes. At 700 °C annealing temperature, ZnO phase with an average nanoparticle size of ∼17.5 nm was observed whereas at 900 °C annealing temperature, Zn 2 SiO 4 phase with an average nanoparticle size of ∼19 nm was observed.
On-Column Method for Nanodisc Preparation and its Application to Solution NMR

Several model systems are currently available for studying membrane proteins. One such relatively new system called nanodiscs has been emerging as a promising alternative. Nanodiscs are discoidal nanolipoproteins, having a nanoscale phospholipid bilayer held together by an amphipathic helical membrane scaffold protein (MSP). Due to their soluble nature, ease of concentration, monodispersity, temperature stability, and compatibility with cell free expression, nanodiscs present a competitive edge over other available systems for studying membrane proteins. With our aim of carrying out structural investigation of membrane proteins within nanodiscs using solution NMR we reduced the diameter of the self assembly complex to its potential limit there by achieving shorter rotational correlation times. This is shown by the noticeable improvement in the spectrum quality of the transmembrane and cytoplasmic domains of integrin αIIb incorporated into these newly developed minimalistic nanodiscs. With the vested interest in generating large “NMR” quantities of homogenous samples in the shortest possible time we developed an on-column method for preparing protein incorporated nanodiscs. Not only did we achieve a rapid, single step, homogenous preparation at one third the time, but we did so with the concurrent separation of protein incorporated discs from the empty discs. This is beneficial as it improves the yield by reducing the number of purification steps, providing a more pure homogeneous sample typically required for structural studies. We have exemplified our new method by reconstituting both bacteriorhodopsin and integrin αIIb using two different strategies within nanodiscs. The nanodiscs prepared by our method have been characterized by Transmission Electron Microscopy, Dynamic Light Scattering and Differential Scanning Calorimetry.
The relationship between maternal rank and companion choice in immature macaques (Macaca mulatta andM. radiata)

Eight bonnet and eight rhesus macaques, ranging from 5–8 months of age, were observed with respect to their choices of companions. These data were then correlated with the dominance ranks of the mothers of the companions involved. Preliminary results showed that the maternal ranks of the rhesus infants were significantly correlated with the maternal ranks of their companions; no such correlation could be demonstrated for the bonnet monkeys. Thus the partner choices of rhesus infants appeared to be more constrained than were those of the bonnets. The results were discussed in relation to the social systems of bonnet and rhesus macaques.
Predator density and competition modify the benefits of group formation in a shoaling reef fish

Synthesis Predation risk experienced by individuals living in groups depends on the balance between predator dilution, competition for refuges, and predator interference or synergy. These interactions operate between prey species as well: the benefits of group living decline in the presence of an alternative prey species. We apply a novel model-fitting approach to data from field experiments to distinguish among competing hypotheses about shifts in predator foraging behavior across a range of predator and prey densities. Our study provides novel analytical tools for analyzing predator foraging behavior and offers insight into the processes driving the dynamics of coral reef fish. Studies of predator foraging behavior typically focus on single prey species and fixed predator densities, ignoring the potential importance of complexities such as predator dilution; predator-mediated effects of alternative prey; heterospecific competition; or predator–predator interactions. Neglecting the effects of prey density is particularly problematic for prey species that live in mixed species groups, where the beneficial effects of predator dilution may swamp the negative effects of heterospecific competition. Here we use field experiments to investigate how the mortality rates of a shoaling coral reef fish (a wrasse: Thalassoma amblycephalum), change as a result of variation in: 1) conspecific density, 2) density of a predator (a hawkfish: Paracirrhites arcatus), and 3) presence of an alternative prey species that competes for space (a damselfish: Pomacentrus pavo). We quantify changes in prey mortality rates from the predator's perspective, examining the effects of added predators or a second prey species on the predator's functional response. Our analysis highlights a model-fitting approach that discriminates amongst multiple hypotheses about predator foraging in a community context. Wrasse mortality decreased with increasing conspecific density (i.e. mortality was inversely density-dependent). The addition of a second predator doubled prey mortality rates, without significantly changing attack rate or handling time – i.e. there was no evidence for predator interference. The presence of a second prey species increased wrasse mortality by 95%; we attribute this increase either to short-term apparent competition (predator aggregation) or to a decrease in handling time of the predator (e.g. through decreased wrasse vigilance). In this system, 1) prey benefit from intraspecific group living though a reduced predation risk, and 2) the benefit of group living is reduced in the presence of an alternative prey species.
Absence of Dislocation Motion in 3C-SiC pn Diodes under Forward Bias

pn diodes have recently been fabricated from 3C-SiC material heteroepitaxially grown atop on-axis 4H-SiC mesa substrate arrays [1,2]. Using an optical emission microscope (OEM), we have investigated these diodes under forward bias, particularly including defective 3C-SiC films with in-grown stacking faults (SFs) nucleated on 4H-SiC mesas with steps from screw dislocations. Bright linear features are observed along directions in electroluminescence (EL) images. These features have been further investigated using electron channeling contrast imaging (ECCI) [3]. The general characteristics of the ECCI images—together with the bright to dark contrast reversal with variations of the excitation error—strongly suggest that the bright linear features are partial dislocations bounding triangular SFs in the 3C-SiC films. However, unlike partial dislocations in 4H-SiC diodes whose recombination-enhanced dislocation motion serves to expand SF regions, all the partial dislocations we observed during the electrical stressing were immobile across a wide range of current injection levels (1 to 1000 A/cm2).
Longitudinal and repeated cross-sectional cluster-randomization designs using mixed effects regression for binary outcomes: bias and coverage of frequentist and Bayesian methods

As medical applications for cluster randomization designs become more common, investigators look for guidance on optimal methods for estimating the effect of group-based interventions over time. This study examines two distinct cluster randomization designs: (1) the repeated cross-sectional design in which centres are followed over time but patients change, and (2) the longitudinal design in which individual patients are followed over time within treatment clusters. Simulations of each study design stipulated a multiplicative treatment effect (on the log odds scale), between 5 and 15 clusters in each of two treatment arms, and followed over two time periods. Estimation options included linear mixed effects models using restricted maximum likelihood (REML), generalized estimating equations (GEE), mixed effects logistic regression using both penalized quasi likelihood (PQL) and numerical integration, and Bayesian Monte Carlo analysis. For the repeated cross-sectional designs, most methods performed well in terms of bias and coverage when clusters were numerous (30) and variability across clusters of baseline risk and treatment effect was modest. With few clusters (two groups of five) and higher variability, only the Bayesian methods maintained coverage. In the longitudinal designs, the common methods of REML, GEE, or PQL performed poorly when compared to numerical integration, while Bayesian methods demonstrated less bias and better coverage for estimates of both log odds ratios and risk differences. The performance of common statistical tools for the analysis of cluster randomization designs depends heavily on the precise design, the number of clusters, and the variability of baseline outcomes and treatment effects across centres.
Effects of Sensor Placement and Errors on Path Following Control of a Mobile Robot-Trailer System

In this paper, effects of sensor location and measurement errors on path tracking control of a mobile robot pulling a trailer are reported. A model for a two-wheeled robot towing a trailer is presented, followed by a state feedback controller designed to position the trailer along a path consisting of lines and circular arcs. An incremental encoder is used to measure the hitch angle between the robot and trailer. A combined GPS/IMU system is used to measure position and orientation of either the robot or the trailer (but not both). The choice of mounting location for the GPS/IMU system, and consequent effects on trailer path tracking performance are explored. The sensitivity of the system to hitch angle errors is also examined for both cases. It is shown that the system is less sensitive to errors in the hitch angle measurement when the GPS/IMU system is located on the trailer.
IN A VARIABLE THERMAL ENVIRONMENT SELECTION FAVORS GREATER PLASTICITY OF CELL MEMBRANES IN DROSOPHILA MELANOGASTER

Theory predicts that developmental plasticity, the capacity to change phenotypic trajectory during development, should evolve when the environment varies sufficiently among generations, owing to temporal (e.g., seasonal) variation or to migration among environments. We characterized the levels of cellular plasticity during development in populations of Drosophila melanogaster experimentally evolved for over three years in either constant or temporally variable thermal environments. We used two measures of the lipid composition of cell membranes as indices of physiological plasticity (a.k.a. acclimation): (1) change in the ratio of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) and (2) change in lipid saturation (number of double bonds) in cool (16°C) relative to warm (25°C) developmental conditions. Flies evolved under variable environments had a greater capacity to acclimate the PE/PC ratio compared to flies evolved in constant environments, supporting the prediction that environments with high among-generation variance favor greater developmental plasticity. Our results are consistent with the selective advantage of a more environmentally sensitive allele that may have associated costs in constant environments.
Involvement of the polyamine pathway in breast cancer progression

These experiments were designed to test the role of the polyamine pathway in breast cancer progression utilizing an experimental system based on the development of ovary-independent rat mammary tumors and their sequential transplantation into syngeneic hosts. Three key enzymes involved in the PA biosynthetic/catabolic pathway (ornithine-decarboxylase (ODC), S-adenosylmethionine decarboxylase (SAMDC), and spermidine/spermine N'-acetyltransferase (SSAT)) were measured in tumors at different stages of progression. The most significant finding was the association between increased ODC activity and the acquisition of a hormone-independent, poorly differentiated phenotype. SSAT levels tended to be higher in hormone-independent tumors and, in this tumor category, they tended to be positively correlated with differentiation. However, significant interaction between hormone dependence and differentiation status on SSAT expression prevented reliable assessment of the possibly complex role of this enzyme in tumor progression. Neither hormone dependence nor differentiation status were correlated with SAMDC levels. We conclude that, among the three enzymes tested, ODC overexpression is the most significant alteration in the PA metabolic pathway associated with breast cancer progression in this experimental system.
Biomechanical analysis of the modified Bristow procedure for anterior shoulder instability: is the bone block necessary?

Background Anterior shoulder instability with bone loss can be treated successfully with the modified Bristow procedure. Opinions vary regarding the role of the soft-tissue sling created by the conjoined tendon after transfer. Therefore, the aim of this study was to determine the effect of the modified Bristow procedure and conjoined tendon transfer on glenohumeral translation and kinematics after creating anterior instability. Methods Eight cadaveric shoulders were tested with a custom shoulder testing system. Range-of-motion, translation, and kinematic testing was performed in 60° of glenohumeral abduction in the scapular and coronal planes under the following conditions: intact joint, Bankart lesion with 20% glenoid bone loss, modified Bristow procedure, and soft tissue–only conjoined tendon transfer. Results A Bankart lesion with 20% bone loss resulted in significantly increased external rotation and translation compared with the intact condition ( P P Conclusions The increase in external rotation suggests that the modified Bristow procedure does not initially restrict joint motion. Translational stability can be restored in a 20% bone loss model without a bone block, suggesting the importance of the soft-tissue sling.