cssi/SciSciGPT-SciSciNet huggingface dataset:
A direct comparison of ERCP teaching models.

Background: Several teaching models for ERCP are now available. Live, anesthetized porcine models have been used for many years, but harvested porcine organ preparations have recently been developed, and computer-based endoscopy simulators now incorporate ERCP modules. Each has proven to be a useful educational modality, but there is no direct comparison among these models. This study compared the performance of these 3 ERCP teaching models. Methods: Twenty endoscopists used each ERCP training model (computer simulator, harvested porcine organ, live anesthetized pig) and then completed a survey grading the realism and performance of each model compared with performance of ERCP in patients. A rank order was established for the models relative to their realism, educational utility, ease of use, and ease of incorporation into a training program. Results: The harvested porcine organ model scored highest on indices of realism, usefulness, and performance, although this reached statistical significance only for “ease of use” (p < 0.05). Conversely, the computer simulator scored significantly lower in most realism scores, although it was felt to be the one model most easily incorporated into a training program. Conclusions: Although each ERCP teaching model has proven to be a useful training modality, the harvested porcine organ model was felt to be the most realistic as well as the most favorable model for instruction in both basic and advanced ERCP. (Gastrointest Endosc 2003;57:886-90.)
Magneli phase Ti4O7 electrode for oxygen reduction reaction and its implication for zinc-air rechargeable batteries

Abstract In this paper, Magneli phase Ti4O7 was successfully synthesized using a TiO2 reduction method, and characterized using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The electrode coated with this Ti4O7 material showed activities for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). For the ORR, several parameters, including overall electron transfer number, kinetic constants, electron transfer coefficient, and percentage H2O2 production, were obtained using the rotating ring-disk electrode (RRDE) technique and the Koutecky–Levich theory. The overall electron transfer number was found to be between 2.3 and 2.9 in 1, 4, and 6 M KOH electrolytes, suggesting that the ORR process on the Ti4O7 electrode was a mixed process of 2- and 4-electron transfer pathways. Electrochemical durability tests, carried out in highly concentrated KOH electrolyte, confirmed that this Ti4O7 is a stable electrode material, suggesting that it should be a feasible candidate for the air-cathodes of zinc-air batteries. To understand the stability of this material, Raman and XPS spectra were also collected for the Ti4O7 samples before and after the stability tests. The results and analysis revealed that a thin layer of TiO2 formed on the Ti4O7 surface, which may have prevented further oxidation into the bulk of the Ti4O7 electrode.
Delithiation Mechanisms in Acid of Spinel LiMn2-xMxO4 (M = Cr, Fe, Co, and Ni) Cathodes

The products formed by the chemical extraction of lithium from LiMn2-xMxO4 (M = Cr, Fe, Co, and Ni) with aqueous sulfuric acid have been structurally and chemically characterized. The amount of lithium extracted is found to be proportional to the initial Mn3+ content, confirming the reaction mechanism, LiMn3+Mn4+O4 → 0.75 Mn2O4 + 0.5 Li2O + 0.5 MnO. Thus, no lithium is extracted from LiMn1.54+Ni0.52+O4 as there is no Mn3+, while complete delithiation occurs in LiMn3+Mn4+O4 to give Mn2O4. The amount of lithium extracted from the other samples is in good agreement with that calculated from the Mn3+ content. The XRD data confirm the maintenance of the spinel structure for the delithiated samples, while the redox titration confirmed the maintenance of oxygen content at 4.0, indicating that no protons were inserted into the lattice during delithiation. The findings could provide more insight on the problem of metal dissolution from cathode materials in lithium-ion batteries. © The Author(s) 2014. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. [DOI: 10.1149/2.0661503jes] All rights reserved.
Effects of rainfall on soil–structure system frequency: Examples based on poroelasticity and a comparison with full-scale measurements

Abstract In this paper, a simple two-dimensional soil–structure interaction model, based on Biot's theory of wave propagation in fluid saturated porous media, is used to explain the observed increase of the apparent frequencies of Millikan library in Pasadena, California, during heavy rainfall and recovery within days after the rain. These variations have been measured for small amplitude response (to microtremors and wind excitation), for which Biot's linear theory is valid. The postulated hypothesis is that the observed increases in frequency are due to the water saturation of the soil. The theoretical model used to explore this hypothesis consists of a shear wall supported by a circular foundation embedded in a poroelastic half-space. This rigid foundation model may be appropriate only for the NS response of Millikan library. This paper presents results for the foundation stiffness, and for the system response for model parameters similar to those for Millikan library (located on alluvium with shear wave velocity of about 300 m/s). The foundation impedance matrix, foundation input motion and system response are compared for dry and fully saturated half-space, with permeable and impermeable foundation. The results show that for embedded foundations, the effects of saturation on the horizontal foundation stiffness are as significant as for the vertical stiffness, contrary to what has been known for surface foundations investigated by other authors. Further, the results suggest a 1–2% increase in system frequency of the first two modes of vibration, depending on the drainage condition along the foundation–soil interface. Such increases agree qualitatively with the observations.
URBAN-RURAL CONTRASTS IN DIET: THE CASE OF CHINA

From an almost infinite variety of available materials, each culture selects those that it accepts as food. Most diets are based on a carbohydrate-rich staple, supplemented by other foods. Animal sources of protein are the most desired but the most expensive to produce and acquire; thus, they command high prestige. With increasing prosperity, diets contain more animal foods and fewer staples (Bennett's law), even as the proportion of income used to purchase food declines (Engel's law). Because of higher incomes in cities, urban residents of developing countries spend a smaller percentage of their income on food than do rural residents, and they eat a higher-quality diet. However, Basta found that recent migrants from the countryside in many developing nations do not enjoy improved diets. This paper reports on research, based on published government statistics, that finds that in China, the poorest segment of the urban population (1) spends a higher percentage of its income on food than do rural people but...
Carbon Partitioning in Green Algae (Chlorophyta) and the Enolase Enzyme

The exact mechanisms underlying the distribution of fixed carbon within photoautotrophic cells, also referred to as carbon partitioning, and the subcellular localization of many enzymes involved in carbon metabolism are still unknown. In contrast to the majority of investigated green algae, higher plants have multiple isoforms of the glycolytic enolase enzyme, which are differentially regulated in higher plants. Here we report on the number of gene copies coding for the enolase in several genomes of species spanning the major classes of green algae. Our genomic analysis of several green algae revealed the presence of only one gene coding for a glycolytic enolase [EC 4.2.1.11]. Our predicted cytosolic localization would require export of organic carbon from the plastid to provide substrate for the enolase and subsequent re-import of organic carbon back into the plastids. Further, our comparative sequence study of the enolase and its 3D-structure prediction may suggest that the N-terminal extension found in green algal enolases could be involved in regulation of the enolase activity. In summary, we propose that the enolase represents one of the crucial regulatory bottlenecks in carbon partitioning in green algae.
Minority carrier lifetime improvement in silicon through laser damage gettering

Minority carrier lifetime engineering in silicon through application of high power laser beams is described. Minority carrier lifetime distributions in silicon wafers are substantially improved through laser damage gettering. Laser operating conditions to obtain optimum lifetime distributions in silicon wafers are given.
The Effects of Period Mutations and Light on the Activity Rhythms of Drosophila melanogaster

Strains of Drosophila melanogaster homozygous for alleles of the period gene (perO, perL, perS, and per+) were reared for multiple generations either in light:dark cycles (LD), continuous illumination (LL), or chronic darkness (DD). The locomotor activity of adult flies from these cultures was monitored in either LL or DD. Flies that were reared and tested in DD had a lower proportion of individuals with normal circadian rhythms than flies reared in LD or LL and tested in DD. The activity rhythms of DD-reared DD-tested animals, when present, showed phase coherence within two out of seven populations, while 8 out of 10 LL-reared DD-tested showed phase coherence. Flies tested in LL were largely devoid of circadian rhythms regardless of their rearing environment. Ultradian rhythms were more evident under conditions disruptive to circadian rhythmicity, but were observed in the presence and absence of circadian rhythms. The periods of the ultradian rhythms of LL-reared DD-tested and LD-reared DD-tested flies varied significantly among genotypes, while in other rearing and testing regimes, no relationship was found.
Nephropathy and establishment of a renal reservoir of HIV type 1 during primary infection.

Human immunodeficiency virus type 1 (HIV-1)–associated nephropathy is the chief cause of chronic renal disease in patients with HIV-1 infection and is now the third leading cause of end-stage renal disease in blacks 20 to 64 years of age.1,2 These patients typically have proteinuria followed by a reduction in the glomerular filtration rate that progresses to end-stage renal disease in a few weeks or months. HIV-1–associated nephropathy is characterized morphologically by focal segmental glomerulosclerosis, tubular microcysts, interstitial fibrosis, and inflammation.2–5 The pathogenesis of HIV-1–associated nephropathy is poorly understood, but increasing evidence suggests it is due to HIV-1 infection . . .
Progress on the launch-vehicle buffeting problem

aerodynamic damping ratio to critical damping for bending oscillations aerodynamic damping coefficient for pitching oscillations static pressure coefficient reference diameter model frequency characteristic length model length scale Mach number power spectrum, ( pressure )-sec/rad power spectrum for model, (psi)-sec/cycle mean square value of fluctuating pressure freestream dynamic pressure correlation function, normalized by [R(Q, xi} Xi)~ R(0,x2,xi)]^ convection speed freestream velocity amplitude of pitching oscillations, deg (xz — Xi) phase angle between pressure at x± and pressure at x>2 time lag rotational frequency, 2irf
Lactate Dehydrogenase Virus and Mouse Embryos

EVIDENCE for in utero transmission of the lactate dehydrogenase virus has been obtained in several laboratories1–3, and this has raised the question as to whether or not the virus affects mouse embryos.
Function of phosducin-like proteins in G protein signaling and chaperone-assisted protein folding

Members of the phosducin gene family were initially proposed to act as down-regulators of G protein signaling by binding G protein βγ dimers (Gβγ) and inhibiting their ability to interact with G protein α subunits (Gα) and effectors. However, recent findings have overturned this hypothesis by showing that most members of the phosducin family act as cochaperones with the cytosolic chaperonin complex (CCT) to assist in the folding of a variety of proteins from their nascent polypeptides. In fact rather than inhibiting G protein pathways, phosducin-like protein 1 (PhLP1) has been shown to be essential for G protein signaling by catalyzing the folding and assembly of the Gβγ dimer. PhLP2 and PhLP3 have no role in G protein signaling, but they appear to assist in the folding of proteins essential in regulating cell cycle progression as well as actin and tubulin. Phosducin itself is the only family member that does not participate with CCT in protein folding, but it is believed to have a specific role in visual signal transduction to chaperone Gβγ subunits as they translocate to and from the outer and inner segments of photoreceptor cells during light-adaptation.
The moderating role of sensory Overresponsivity in HPA activity: a pilot study with children diagnosed with ADHD.

Objective: To determine if sensory overresponsivity (SOR) is a moderating condition impacting the activity of the Hypothalamic Pituitary Adrenal (HPA) Axis in children with ADHD. Method: Participants were children with (n = 24) and without ADHD (n = 24). Children in the ADHD group were divided into SOR (ADHDs) and non-SOR (ADHDt) groups using the Sensory Over-Responsivity Inventory. All children participated in the Sensory Challenge Protocol. Salivary cortisol was used as a measure of HPA activity. Two prechallenge and seven postchallenge samples of saliva were taken. Cortisol patterns between groups were examined using a mixed-effects ANOVA. Results: There was a borderline significant difference found between the ADHDt and ADHDs group (p = .056) and a significant difference between ADHDt and the typical group (p = .014). Conclusion: Preliminary results support the premise that SOR may be a moderating variable used to create subgroups in diagnostic populations such as ADHD. (J. of Att. Dis. XXXX; XX(X) xx-xx)
Rates of convex approximation in non-hilbert spaces

This paper deals with sparse approximations by means of convex combinations of elements from a predetermined “basis” subsetS of a function space. Specifically, the focus is on therate at which the lowest achievable error can be reduced as larger subsets ofS are allowed when constructing an approximant. The new results extend those given for Hilbert spaces by Jones and Barron, including, in particular, a computationally attractive incremental approximation scheme. Bounds are derived for broad classes of Banach spaces; in particular, forL p spaces with 1<p<∞, theO (n −1/2) bounds of Barron and Jones are recovered whenp=2.
Estrogen and Recurrent UTI: What Are the Facts?

Estrogen therapy promotes resistance to urinary tract infections in postmenopausal women by altering lower urinary tract mucosal defense mechanisms (Luthje et al., this issue).
Inferring the evolutionary history of divergence despite gene flow in a lizard species, Scincella lateralis (Scincidae), composed of cryptic lineages

Although recent radiations are fruitful for studying the process of speciation, they are difficult to characterize and require the use of multiple loci and analytical methods that account for processes such as gene flow and genetic drift. Using multilocus sequence data, we combine hierarchical cluster analysis, coalescent species tree inference, and isolation-with-migration analysis to investigate evolutionary relationships among cryptic lineages of North American ground skinks. We also estimate the extent that gene flow has accompanied or followed diversification, and also attempt to account for and minimize the influence of gene flow when reconstructing relationships. The data best support seven largely parapatric populations that are broadly concordant with mitochondrial (mt)DNA phylogeography throughout most of the species range, although they fail to fully represent extensive mtDNA divergence along the Gulf Coast. Relationships within and among three broad geographical groups are well supported, despite evidence of gene flow among them. Rejection of an allopatric divergence model partially depends on the inclusion of samples from near parapatric boundaries in the analyses, suggesting that allopatric divergence followed by recent migration may best explain migration rate estimates. Accounting for geographical variation in patterns of gene flow can improve estimates of migration‐divergence parameters and minimize the influence of contemporary gene flow on phylogenetic inference. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107, 192‐209.
Mutational analysis of ganglioside GM(1)-binding ability, pentamer formation, and epitopes of cholera toxin B (CTB) subunits and CTB/heat-labile enterotoxin B subunit chimeras.

Variants of cholera toxin B subunit (CTB) were made by bisulfite- and oligonucleotide-directed mutagenesis of the ctxB gene. Variants were screened by a radial passive immune hemolysis assay (RPIHA) for loss of binding to sheep erythrocytes (SRBC). Variant CTBs were characterized for the formation of immunoreactive pentamers, the ability to bind ganglioside GM(1) in vitro, and reactivity with a panel of monoclonal anti-CTB antibodies. Substitutions at eight positions (i.e., positions 22, 29, 36, 45, 64, 86, 93, and 100) greatly reduced the yield of immunoreactive CTB. RPIHA-negative substitution variants that formed immunoreactive pentamers were obtained for residues 12, 33, 36, 51, 52 + 54, 91, and 95. Tyrosine-12 was identified as a novel residue important for GM(1) binding since, among all of the novel variants isolated with altered RPIHA phenotypes, only CTB with aspartate substituted for tyrosine at position 12 failed to bind significantly to ganglioside GM(1) in vitro. In contrast, CTB variants with single substitutions for several other residues (Glu-51, Lys-91, and Ala-95) that participate in GM(1) binding, based on the crystal structure of CTB and the oligosaccharide of GM(1), were not appreciably altered in their ability to bind GM(1) in vitro, even though they showed altered RPIHA phenotypes and did not bind to SRBC. Hybrid B genes made by fusing ctxB and the related Escherichia coli heat-labile enterotoxin eltB genes at codon 56 produced CTB variants that had 7 or 12 heat-labile enterotoxin B residue substitutions in the amino or carboxyl halves of the monomer, respectively, each of which which also bound GM(1) as well as wild-type CTB. This collection of variant CTBs in which 47 of the 103 residues were substituted was used to map the epitopes of nine anti-CTB monoclonal antibodies (MAbs). Each MAb had a unique pattern of reactivity with the panel of CTB variants. Although no two of the epitopes recognized by different MAbs were identical, most of the single amino acid substitutions that altered the immunoreactivity of CTB affected more that one epitope. The tertiary structures of the epitopes of these anti-CTB MAbs are highly conformational and may involve structural elements both within and between CTB monomers. Substitution of valine for alanine at positions 10 and 46 had dramatic effects on the immunoreactivity of CTB, affecting epitopes recognized by eight or six MAbs, respectively.
Effects of Internally Mounted Cathodes on Hall Thruster Plume Properties

The effects of cathode position on the operation and plume properties of an 8-kW Hall thruster are discussed. Thruster operation was investigated at operating conditions ranging from 200 to 500 V of discharge voltage, 10-40 A of discharge current, and 2-8 kW of discharge power, with a cathode positioned either in the traditional externally mounted configuration outside the outer magnetic pole piece or in an internally mounted configuration central to the inner magnetic core. With the external cathode, substantial emission in the visible spectrum that follows magnetic field lines surrounds the exterior pole pieces of the thruster. With the internal cathode, the emission is largely absent while the cathode plume is compressed and elongated in the axial direction by the strong axial magnetic field on the thruster centerline. Discharge current oscillation and ion species fraction measurements were found to be similar for the cathode locations, whereas the operation with the internal cathode was found to favor an improved coupling of the cathode plume with the thruster discharge. Ion current density measurements show that with respect to externally mounted designs, internally mounted cathodes reduce plume divergence and increase the symmetry of the near-field plume. The impacts of internally mounted cathodes on thruster physics and spacecraft integration activities are assessed.
Maximum likelihood spectral estimation and its application to narrow-band speech coding

Itakura and Saito [1] used the maximum likelihood (ML) method to derive a spectral matching criterion for autoregressive (i.e., all-pole) random processes. In this paper, their results are generalized to periodic processes having arbitrary model spectra. For the all-pole model, Kay's [2] covariance domain solution to the recursive ML (RML) problem is cast into the spectral domain and used to obtain the RML solution for periodic processes. When applied to speech, this leads to a method for solving the joint pitch and spectrum envelope estimation problems. It is shown that if the number of frequency power measurements greatly exceeds the model order, then the RML algorithm reduces to a pitch-directed, frequency domain version of linear predictive (LP) spectral analysis. Experiments on a real-time vocoder reveals that the RML synthetic speech has the quality of being heavily smoothed.
Xylose disposition in humans as a function of age.

D-Xylose disposition was examined in 24 healthy men between 32 and 85 years of age. Xylose was administered as a 5 gm iv infusion and as a 25 gm po solution. Serum xylose concentrations and urinary excretion of intact xylose were determined. There were statistically significant inverse relationships with age for each of the following parameters after intravenous infusion: elimination rate constant (r2 = 0.71); systemic clearance (r2 = 0.66); renal clearance (r2 = 0.66); and nonrenal clearance (r2 = 0.35). Similar inverse relationships were found after oral dosing for the elimination rate constant (r2 = 0.69) and renal clearance (r2 = 0.54). There was no significant age relationship for the apparent volume of distribution or the steady-state volume of distribution. The percentage of the oral and intravenous dose recovered in urine up to 5 hours after dosing was significantly and inversely correlated with age. The implications of the latter finding are discussed with regard to the interpretation of the xylose tolerance test used to assess gastrointestinal absorptive capacity. Clinical Pharmacology and Therapeutics (1986) 39, 697–702; doi:10.1038/clpt.1986.121
Incidence of Morbidity From Penetrating Palate Trauma

BACKGROUND: The true rate of neurologic sequelae and infection from penetrating palatal trauma in children is unknown, which leads to significant variation in testing and treatment. OBJECTIVES: To (1) determine the incidence of stroke and infection in well-appearing children with penetrating palatal trauma and (2) describe patterns of testing and treatment for uncomplicated palatal trauma. METHODS: We assembled a retrospective cohort of children aged 9 months to 18 years with palatal trauma seen in the emergency department (ED) at a tertiary care pediatric hospital. Patients met the following definition: well-appearing with normal neurologic examination and a palate laceration but no findings requiring immediate operative care. Stroke was defined as any abnormal neurologic examination secondary to palatal trauma. Infection was defined as cellulitis or abscess secondary to palatal injury. All abnormal computed tomographic angiography (CTA) findings, except for free air, were considered positive and potentially significant. RESULTS: We identified 1656 potential subjects. A total of 995 of 1656 subjects were screened, and 205 of 995 met the case definition. A total of 122 of 205 had follow-up through at least 1 week after injury. The incidence of stroke in our study population was 0% (95% confidence interval [CI]: 0–2.5). One of 116 patients developed infection, for an incidence of 0.9% (95% CI: 0–5.3). A total of 90 of 205 (44%) subjects had CTA scans; the results of 9 (10%) were positive. No patients with positive CTA findings required operative care. No patients received anticoagulant medications. CONCLUSIONS: The incidence of morbidity from penetrating palatal trauma in the well-appearing child is extremely low. Diagnostic evaluation in the ED did not prompt clinical interventions other than antibiotics.
Pruning recurrent neural networks for improved generalization performance

The experimental results in this paper demonstrate that a simple pruning/retraining method effectively improves the generalization performance of recurrent neural networks trained to recognize regular languages. The technique also permits the extraction of symbolic knowledge in the form of deterministic finite-state automata (DFA) which are more consistent with the rules to be learned. Weight decay has also been shown to improve a network's generalization performance. Simulations with two small DFA (/spl les/10 states) and a large finite-memory machine (64 states) demonstrate that the performance improvement due to pruning/retraining is generally superior to the improvement due to training with weight decay. In addition, there is no need to guess a 'good' decay rate. >
Validity of the Additive White Gaussian Noise Model for Quasi-Linear Long-Haul Return-to-Zero Optical Fiber Communications Systems

In this paper, we study the validity and limitations of the additive white Gaussian noise (AWGN) model in quasi-linear, long-haul, return-to-zero, direct-detection optical fiber communications systems. Our approach is to compare bit-error ratios (BERs) computed using the additive white Gaussian noise method to those obtained using standard and multicanonical Monte Carlo (MMC) simulations and to a noise-linearization method, referred to as the noise covariance matrix (NCM) method. We show that the AWGN method provides a very good approximation to the actual system BER for power levels and dispersion profiles that are used in typical modern-day quasi-linear systems. For example, the BER obtained using the AWGN method is within a factor of 4 of the actual system BER computed using MMC simulations for a realistic 10 Gb/s, 6000 km system based on dispersion-shifted fiber in which the peak signal power at the transmitter is 1 mW and the absolute residual dispersion at the receiver is less than 200 ps/nm. However, when the peak power is increased to about 4 mW, or the average map dispersion is zero and the absolute residual dispersion exceeds 200 ps/nm, the AWGN and NCM methods may simultaneously breakdown due to a combination of nonlinear signal-noise and noise-noise interactions during transmission. In addition, for a 5000 km system based on low-nonlinearity D + and D - fiber with an average map dispersion that is 4% of the dispersion variation within the map, and that operates at a peak power of 5 mW, we find that the BERs obtained using the AWGN and NCM methods are about 500 times smaller than the actual system BER computed using MMC simulations.
Pharmacogenomics: analysing SNPs in the CYP2D6 gene using amino acid properties

The CYP2D6 gene is responsible for metabolising a large portion of the commonly prescribed drugs. Because of its importance, various approaches have been taken to analyse CYP2D6 and Single Nucleotide Polymorphisms (SNPs) throughout its sequence. This study introduces a novel method to analyse the effects of SNPs on encoded protein complexes by focusing on the biochemical properties of each non-synonymous substitution using the program TreeSAAP. Our results show four SNPs in CYP2D6 that exhibit radical changes in amino acid properties which may cause a lack of functionality in the CYP2D6 gene and contribute to a person's inability to metabolise specific drugs.
Designing power system simulators for the smart grid: Combining controls, communications, and electro-mechanical dynamics

Open source software has a leading role in research on simulation technology for electrical power systems. Research simulators demonstrate new features for which there is nascent but growing demand not yet provided for by commercial simulators. Of particular interest is the inclusion of models of software-intensive and communication-intensive controls in simulations of power system transients. This paper describes two features of the ORNL power system simulator that help it meet this need. First is its use of discrete event simulation for all aspects of the model: control, communication, and electro-mechanical dynamics. Second is an interoperability interface that enables the ORNL power system simulator to be integrated with existing, discrete event simulators of digital communication systems. The paper concludes with a brief discussion of how these aspects of the ORNL power system simulator might be inserted into production-grade simulation tools.
Replication Protein A (RPA): The Eukaryotic SSB

Replication protein A (RPA) is a heterotrimeric single-stranded DNA-binding protein that is highly conserved in eukaryotes. RPA plays essential roles in many aspects of nucleic acid metabolism, including DNA replication, nucleotide excision repair, and homologous recombination. In this review, we provide a comprehensive overview of RPA structure and function and highlight the more recent developments in these areas. The last few years have seen major advances in our understanding of the mechanism of RPA binding to DNA, including the structural characterization of the primary DNA-binding domains (DBD) and the identification of two secondary DBDs. Moreover, evidence indicates that RPA utilizes a multistep pathway to bind single-stranded DNA involving a particular molecular polarity of RPA, a mechanism that is apparently used to facilitate origin denaturation. In addition to its mechanistic roles, RPA interacts with many key factors in nucleic acid metabolism, and we discuss the critical nature of many of th...
An Evaluation of Algorithms to Solve for Do-Not-Exceed Limits for Renewable Resources

As power systems become more reliant on intermittent resources, system operators are faced with the fact that the availability of intermittent resources is beyond human control and largely unpredictable. Due to the lack of compliance from intermittent resources to follow strict dispatch instructions, the dispatch instruction for an intermittent resource is proposed to be a desired dispatch range or a do-not-exceed (DNE) limit. In this paper, a two-stage robust optimization problem determines the DNE limits, which define the region where the system is guaranteed to reliably handle any wind realization within the specified DNE limit range. Two algorithms are implemented in this paper, each of which can handle the bilinear sub-problem in this two-stage problem. The results show that local search algorithms do not perform well when compared to a big-M based MILP reformulation. All numerical results are based on the IEEE-118 bus test system.
AGAINST ALL ODDS:The Survival Strategies of Deinococcus radiodurans

Bacteria of the genus Deinococcus exhibit an extraordinary ability to withstand the lethal and mutagenic effects of DNA damaging agents-particularly the effects of ionizing radiation. These bacteria are the most DNA damage-tolerant organisms ever identified. Relatively little is known about the biochemical basis for this phenomenon; however, available evidence indicates that efficient repair of DNA damage is, in large part, responsible for the deinococci's radioresistance. Obviously, an explanation of the deinococci's DNA damage tolerance cannot be developed solely on the basis of the DNA repair strategies of more radiosensitive organisms. The deinococci's capacity to survive DNA damage suggests that (a) they employ repair mechanisms that are fundamentally different from other prokaryotes, or that (b) they have the ability to potentiate the effectiveness of the conventional complement of DNA repair proteins. An argument is made for the latter alternative.
Maldescent of the testes

Abstract Cryptorchidism is the most common congenital abnormality. The incidence is increasing and currently stands at 5.5% of all boys born at full term. Approximately one-half will continue to descend into the scrotum; the majority will do so by three months of age. The current embryological theories of testicular descent are discussed. The diagnosis, management and implications of cryptorchidism are reviewed.
FURTHER ANALYSIS OF THE SEPARATE AND INTERACTIVE EFFECTS OF METHYLPHENIDATE AND COMMON CLASSROOM CONTINGENCIES

We evaluated separate and interactive effects between common classroom contingencies and methylphenidate (MPH) on disruptive and off-task behaviors for 4 children with a diagnosis of attention deficit hyperactivity disorder. Analogue conditions consisting of contingent teacher reprimands, brief time-out, no interaction, and alone were conducted in a multielement design. Medication status (MPH or placebo) was alternated across days in a superordinate multielement design. Results indicate that (a) the behavioral effects of MPH were influenced by one or more of the analogue conditions for each participant, and (b) time-out was associated with zero or near-zero levels of both disruptive and off-task behavior for 3 of the 4 participants during MPH and placebo conditions. Implications for the clinical effectiveness of MPH and possible behavioral mechanisms of action of MPH in applied settings are discussed.
Development and Validation of an Instrument to Determine Patient Knowledge: The Oral Anticoagulation Knowledge Test

Background:Studies examining the relationship between patient knowledge regarding warfarin therapy and its safe and effective use are limited by the lack of validated knowledge assessment tools.Objective:To develop and validate an instrument to assess patient knowledge regarding oral anticoagulation therapy.Methods:Four nationally recognized anticoagulation experts participated in the instrument development process to ensure content validity. The Oral Anticoagulation Knowledge (OAK) test was administered to subjects on warfarin and a group of age-matched subjects not on warfarin to assess construct validity. A subgroup of warfarin subjects were retested approximately 2–3 months after initial testing to assess test–retest reliability. Internal consistency reliability was assessed by calculating a Kuder-Richardson 20 value. Item analysis was used to assess performance of individual questions.Results:An initial 23 item instrument was pilot tested for readability and comprehension. The OAK test was administer...
Distinct autophosphorylation sites sequentially produce autonomy and inhibition of the multifunctional Ca2+/calmodulin-dependent protein kinase

The multifunctional Ca2+/calmodulin-dependent protein kinase (multifunctional CaM kinase) may be an important mediator for neurotransmitters and hormones that utilize Ca2+ as a “second messenger.” We examined the ability of autophosphorylation to convert the multifunctional CaM kinase to a Ca2+/calmodulin-independent (autonomous) form to determine whether autophosphorylation is a mechanism for short- or long-term enhancement of Ca2+ action. As the kinase incorporates phosphate during continuous stimulation by Ca2+/calmodulin, its ability to phosphorylate exogenous substrates becomes increasingly autonomous. Withdrawal of Ca2+ after a critical level of phosphate incorporation is reached leads to a “burst” or rapid increase in Ca2+-independent autophosphorylation. The “burst” of autophosphorylation is distinct from the initial Ca2+-dependent autophosphorylation, however, since it inhibits substrate phosphorylation. Both Ca2+-dependent and Ca2+-independent substrate phosphorylation are inhibited by this autonomous autophosphorylation. Thus, autophosphorylation has a dual role in modulating the activity of multifunctional CaM kinase. It initially enables the kinase to continue phosphorylating substrates after Ca2+ levels decline, but it eventually suppresses this autonomous activity. Tryptic phosphopeptide mapping demonstrates that appearance of phosphothreonine-containing peptides is common to several conditions used to generate an autonomous enzyme. Sequencing reveals the critical “autonomy” site to be threonine286. The inhibitory mode of autophosphorylation involves 3 additional phosphopeptides containing a serine and a threonine residue.
SEQUENCE STRATIGRAPHY OF DINOSAUR LAKE: SMALL SCALE FLUVIO-DELTAIC STRATAL RELATIONSHIPS OF A DINOSAUR ACCUMULATION AT THE AARON SCOTT QUARRY, MORRISON FORMATION, SAN RAFAEL SWELL, UTAH

Stratal geometries, cyclical stacking patterns, and taphonomic analysis of the Aaron Scott Quarry in the Jurassic Morrison Formation indicate that sediments accumulated within a prograding fluvio-deltaic lacustrine system. Sediments were deposited during the progressive fill of a large lake. Stratal geometries and stacking patterns display relationships similar to larger-scale deltaic sequences caused by fluctuations in base level. Stratigraphic, paleontologic, and sedimentologic analysis indicates that water-volume-driven, base-level changes were responsible for the accumulation and preservation of the assemblage. The assemblage accumulated during a lowering of base level during the late stages of an overall fall caused by drought and was buried by a rapid rise at the end of the drought. Fluvio-deltaic lake fill consists of numerous off-lapping beds of sparsely bioturbated, coarsening-upward mudstone capped by thin, bioturbated silty mudstones. Erosional surfaces dip to the west and cut older mudstone parasequences. Retrogradation, aggradation, and progradation of strata typify stratigraphic trends above the erosion surface. Coarse braided stream sands cap off successive sequences as accommodation is filled prior to the next lowstand and sequence boundary incisement. The quarry is a large, taxonomically diverse deposit formed by the concentration of animals at the margins of a lake during a drought. Animals congregated near the banks as smaller watering holes dried. Bone locations and orientations indicate reworking by fluvial and wave currents. Vertical preservational trends indicate accumulation over a period of years. Trace fossil, lake invertebrate distributions, and sedimentological evidence indicate that periodic establishment of oxygen stratification within lake waters may have contributed to conditions favorable for bone preservation.
An Investigation of the Effect of Plasma Treatment on the Surface Properties and Adhesion in Sheet Molded Composite (SMC) Material

Abstract Sheet molded composite was treated with different plasmas (oxygen, dry air, nitrogen, and argon). Plasma treatment of SMC alters the surface properties in a manner dependent on the type of plasma used and the time of treatment. The surface properties were evaluated using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Fourier transform infrared spectros-copy (FTIR). A two-part urethane adhesive was used to prepare lap shear specimens. Untreated SMC, plasma-treated SMC, and primer-treated SMC were prepared, bonded and tested. The surface properties of the failed specimens were measured. The adhesion characteristics of SMC and the surface properties of the failed specimens were correlated with the type of treatment and the surface properties of treated SMC. Comparison of the surface and adhesive properties of plasma-treated samples with those for untreated samples indicates a) an increase in roughness, b) an increase in the level of SMC surface oxidation, and c) an i...
Seabed shear modulus profile inversion using surface gravity (water) wave-induced bottom motion

Summary. The motion of a layered seabed induced by propagating gravity water waves is modelled by the coupling matrix for a massless incompressible elastic bed according to Yamamoto. An amplitude inversion scheme is developed to extract the bottom shear modulus profile from the motion of the seabed at a point on the bed surface using the linear inverse theory combined with the Yamamoto theory of wave-seabed interaction. Numerical tests using synthetic data without noise confirmed that the inversion is unique and consistent. The inversion technique is applied to a set of field data from the Mississippi River Delta. A good agreement is obtained between the inverted profile and the direct measurements.
Liberal and Conservative Political Ideology, Experiences of Harassment, and Perceptions of Campus Climate

The purpose of this study was to examine the relations among racial-ethnic group membership, political ideology (i.e., conservative and liberal), and perceptions of general campus climate (GCC) and of campus climate for racial-ethnic minorities (RECC). One hundred and thirty-six (136) undergraduate, graduate, and professional students participated in this study at a large public Midwestern university. A series of multivariate analyses of variance, hierarchical regressions, and mediation analyses were conducted. Findings indicated that Whites endorsed more positive perceptions of campus climate, reported fewer experiences of racial-ethnic harassment, and endorsed less liberal political ideological beliefs than people of color. No racial differences in conservative ideology emerged. After controlling for racial-ethnic group membership, results showed that experiences of racial-ethnic harassment predicted both GCC and RECC, whereas conservative ideology only predicted RECC. Post hoc analyses demonstrated that experiences of racial-ethnic harassment fully mediated the relationship between racial-ethnic group membership and GCC, but only partially mediated the relationship between racial-ethnic group membership and RECC. Neither conservative nor liberal ideologies were significant mediators. Implications for future research and practice are provided.
The anion‐exchange substrate shuttle process: A new approach to two‐stage biomethanation of organic and toxic wastes

A novel biomethanation process configuration is described which uses improved biocatalysts to enhance the productivity and stability of waste biomethanation systems. The design facilitates the maintenance of acetogenic and methanogenic bacteria under optimum substrate concentrations far above their K(s) values in a two-stage biomethanation system with closed loop reactors. Volatile fatty acid anions (VFA anions) are provided as substrates for the methanogenic stage by using an anion exchange unit coupled to the acidogenic stage. The slow growing and sensitive acetogenic and methanogenic bacteria are protected from oxygen, cationic pollutants, toxins, and microbial contamination by use of the substrate shuttle process. Due to the closed loop process configuration, washout of the ecoengineered biocatalysts is excluded. The modular system configuration allows industrial mass production of the system components. The new biomethanation process enhances both the BTU content of the gas and the methane production over state-of-the-art anaerobic digestor bioreactor concepts.
Hepatitis B Virus Reactivation After Cytotoxic Chemotherapy: The Disease and Its Prevention

Reactivation of hepatitis B virus (HBV) is a well-recognized complication in patients with chronic HBV infection who receive cytotoxic or immunosuppressive therapy. In most cases, reactivations occur in patients who are carriers of HBV infection showing positive hepatitis B surface antigen (HBsAg). Reactivation also may occur in patients with resolved infection who are HBsAg negative, anti–HBs positive, and anti–hepatitis B core positive. HBV reactivations can lead to severe flares that may be life-threatening unless recognized and treated promptly. Physician awareness is essential because prophylactic antiviral treatment can diminish the occurrence and improve the outcome of such episodes. Patients undergoing cytotoxic therapy should be checked routinely for HBV serologic markers and serum HBV DNA levels. Patients who are HBV carriers or anti–hepatitis B core positive should be monitored closely during and after the administration of cytotoxic chemotherapy. Prophylactic treatment with a nucleoside or nucleotide analogue should be considered strongly to prevent HBV reactivation in these patients.
Spin-Labeled Nucleic Acids

Major progress was made during recent years in applying spin-labeled nucleic acids to biological systems due to the synthesis of new spin-labeled nucleic acid substrates recognized by a variety of nucleic acid polymerizing enzymes. The ready availability of oligonucleotides of defined sequence to serve as templates or primers has made it possible to incorporate spin-labeled bases sequence-specifically enzymatically into DNAs of small as well as large molecular weight. Secondly the synthesis of phosphotriester and phosphoramidate derivatives of spin-labeled nucleotides made it practical routinely to incorporate spin-labeled bases sequence specifically into oligonucleotides with a DNA synthesizer. In addition better analytical methods based on HPLC, FPLC, and CE technology can now be routinely used to verify the quality of spin-labeled nucleic acids. Progress in designing and automating EPR instrumentation and data collection also makes it feasible to work quantitatively with small amounts of spin-labeled oligonucleotides that can serve for instance as hybridization probes with as little as picomole amounts of material. Lastly new theoretical models were developed to allow the extraction of motional ordering and of global and local motion rates from spin-labeled nucleic acid EPR spectra. Success in addressing the question of how to decouple global motion from internal motions now makes it possible to work on gaining a more comprehensive understanding phenomena involving nucleic acids that are critical in cellular development.
Green Copier Recycling: Entrepreneur Meets Private Equity

This case is appropriate for courses in entrepreneurship and business strategy. It raises issues about the process of dealing with private equity firms and how to know what is a market deal. It also presents the difficult issues facing the builder of a successful business when he is presented with an unsolicited offer that involves losing control of his business to in a fragmented consolidating industry. The terms of the deal include the buyer bringing in a new COO and an earn-out. Does the entrepreneur exit or risk going it alone?