cssi/SciSciGPT-SciSciNet huggingface dataset:
Suppression of Coronavirus Replication by Inhibition of the MEK Signaling Pathway

We previously demonstrated that infection of cultured cells with murine coronavirus mouse hepatitis virus (MHV) resulted in activation of the mitogen-activated protein kinase (Raf/MEK/ERK) signal transduction pathway (Y. Cai et al., Virology 355:152-163, 2006). Here we show that inhibition of the Raf/MEK/ERK signaling pathway by the MEK inhibitor UO126 significantly impaired MHV progeny production (a reduction of 95 to 99% in virus titer), which correlated with the phosphorylation status of ERK1/2. Moreover, knockdown of MEK1/2 and ERK1/2 by small interfering RNAs suppressed MHV replication. The inhibitory effect of UO126 on MHV production appeared to be a general phenomenon since the effect was consistently observed in all six different MHV strains and in three different cell types tested; it was likely exerted at the postentry steps of the virus life cycle because the virus titers were similarly inhibited from infected cells treated at 1 h prior to, during, or after infection. Furthermore, the treatment did not affect the virus entry, as revealed by the virus internalization assay. Metabolic labeling and reporter gene assays demonstrated that translation of cellular and viral mRNAs appeared unaffected by UO126 treatment. However, synthesis of viral genomic and subgenomic RNAs was severely suppressed by UO126 treatment, as demonstrated by a reduced incorporation of [3H]uridine and a decrease in chloramphenicol acetyltransferase (CAT) activity in a defective-interfering RNA-CAT reporter assay. These findings indicate that the Raf/MEK/ERK signaling pathway is involved in MHV RNA synthesis.
Prediction of vancomycin pharmacodynamics in children with invasive methicillin-resistant Staphylococcus aureus infections: a Monte Carlo simulation.

Abstract Background: Due to the emergence of community-associated strains, the prevalence of invasive methicillin-resistant Staphylococcus aureus (MRSA) infections has increased substantially in pediatric patients. A vancomycin AUC 0–24 /MIC index >400 best predicts treatment outcomes for invasive MRSA infection in adults. Data on whether recommended vancomycin doses in children achieve this break point are lacking. Objective: This study aimed to assess the likelihood that currently recommended vancomycin doses in children achieve AUC 0–24 /MIC >400. Methods: Vancomycin AUC 0–24 /MIC predictions were conducted across a range of dosages (40–70 mg/kg/d) using a Monte Carlo simulation (n = 5000). AUC 0–24 was calculated as daily dose divided by vancomycin clearance, and daily dose was fixed for a given simulation. Three literature-reported estimates in children were used to define vancomycin clearance and its variance. For the MIC distribution of MRSA isolates, susceptibility data were obtained from the University of California, San Francisco Children's Hospital, San Francisco, California (n = 180; 40% ≤0.5 mg/L; 59% = 1 mg/L; and 1% = 2 mg/L). Results: Using the recommended empiric dosage of 40 mg/kg/d, 58% to 66% of children were predicted to achieve AUC 0–24 /MIC >400. Increasing the vancomycin dosage to 60 mg/kg/d substantially increased the likelihood (88%–98%) of achieving this pharmacodynamic target. On sensitivity analysis, a dosage of 40 mg/kg/d was more strongly influenced by small changes in MIC compared with 60 mg/kg/d. Conclusions: Recommended empiric vancomycin dosing in children (40 mg/kg/d) was not predicted to consistently achieve the pharmacodynamic target of AUC 0–24 /MIC >400 for invasive MRSA infections. A vancomycin dosage of 60 mg/kg/d was predicted to optimize achievement of this target in children.
Enzymic production of cellotriose from cellulose.

Abstract Cellotriose is produced in appreciable amounts by action of cellulolytic filtrates of Streptomyces sp. on highly reactive cellulose. Cellotriose and cellobiose accumulate because enzymes capable of hydrolyzing them are absent.
The Sources of Anti-US Attitudes

America: Sovereign Defender or Cowboy Nation? Edited by Vladimir Shlapentokh, Joshua Woods, Eric Shiraev. Aldershot: Ashgate, 2005. 220 pp., $59.95 (ISBN: 0-7546-4428-6). Over the past two decades students of foreign policy have been paying increased attention to the domestic sources of state behavior. Because much of this research has focused on the United States, it has become de rigeur among those working in this area to advocate broadening the study of the relationships among public opinion, the media, and foreign policy. In America: Sovereign Defender or Cowboy Nation? Vladimir Shlapentokh, Joshua Woods, and Eric Shiraev bring together twelve original essays that explore the domestic sources of reactions to the attacks of September 11 and the subsequent US response in seven countries: Germany, Russia, Colombia, China, Egypt, India, and Lithuania. As is common with edited volumes, the contributions are uneven. However, taken as a whole the essays provide a roadmap for future comparative research into the role of media as an intervening variable between mass public opinion and decision makers. America: Sovereign Defender or Cowboy Nation? addresses three related, though customarily separate, literatures in foreign policy analysis (FPA). First, the chapters respond to questions that have received much attention in policy-oriented journals and similar venues regarding the purposes and implications of US preponderance (Huntington 1993; Kagan 2002). Second, the volume fits well into a developing literature in comparative FPA that addresses the role of domestic politics in the formulation of state policy (Nacos, Shapiro, and Isernia 2000). In this respect, the editors have selected cases that provide a window on the interaction among public opinion, media coverage, and foreign policy across a range of …
A data collection protocol for real-time sensor applications

The nature of many sensor applications as well as continuously changing sensor data often imposes real-time requirements on wireless sensor network protocols. Due to numerous design constraints, such as limited bandwidth, memory and energy of sensor platforms, and packet collisions that can potentially lead to an unbounded number of retransmissions, timeliness techniques designed for real-time systems and real-time databases cannot be applied directly to wireless sensor networks. Our objective is to design a protocol for sensor applications that require periodic collection of raw data reports from the entire network in a timely manner. We formulate the problem as a graph coloring problem. We then present TIGRA (Timely Sensor Data Collection using Distributed Graph Coloring) - a distributed heuristic for graph coloring that takes into account application semantics and special characteristics of sensor networks. TIGRA ensures that no interference occurs and spatial channel reuse is maximized by assigning a specific time slot for each node. Although the end-to-end delay incurred by sensor data collection largely depends on a specific topology, platform, and application, TIGRA provides a transmission schedule that guarantees a deterministic delay on sensor data collection.
Educational multilateralism in a changing world order: Unesco and the limits of the possible

Abstract This paper provides a critical re-valuation of Unesco's work in education over the last five decades, updating this story to include the most recent decade of crisis and reform within the organization and within the United Nations more broadly. Drawing on interviews within Unesco, a wide range of Unesco documentation and secondary sources, the paper addresses two main questions. First, what can Unesco's 52 years of experience in the field of education tell us about the possibilities and limits of multilateral cooperation in education? Second, how (and how successfully) has Unesco adapted to changes in world order over the last two decades?
Kiln-firing as a Technique for studying Nest-building Behaviour of Mud-dauber Wasps

IN a study of the utilization of mud by mud-dauber wasps, kiln-firing has been investigated as a technique for quick identification of the mud sources used by the wasps. Sceliphron cementarium (Drury) has been found to construct nests using radioactive mud from the waste disposal pits on the Atomic Energy Reservation at the Oak Ridge National Laboratory. Trypoxylon politum (Say) seldom used radioactive mud, although it nested in the same sites as Sceliphron1. Information about the kinds of mud used, and the sources of such muds, was necessary for interpreting the behaviour of the wasps in this unique situation.
Inhibition of marrow CFU-E colony formation from human immunodeficiency virus-infected patients by β- and γ-interferon

Increased production of cytokines such as beta-interferon (IFN) and gamma-IFN may contribute to the anemia frequently observed in patients with human immunodeficiency virus (HIV) infection. The hypothesis that HIV infection might enhance the susceptibility of erythroid progenitors to cytokine-mediated inhibition was evaluated by comparing the effects of beta- and gamma-IFN on in vitro colony formation by marrow erythroid colony-forming units (CFU-E) from HIV patients, normal volunteers, and anemic non-HIV-infected individuals. CFU-E colony formation from HIV patients was not significantly different from controls, and the degree of inhibition by IFN did not differ among patient subsets. HIV infection does not appear to impair baseline CFU-E colony formation, nor does it appear to enhance the susceptibility of CFU-E to suppression by cytokines.
Ethical Theory Applied to Online Practices

Craig, D. A. (2011). Excellence in online journalism: Exploring current practices in an evolving environment. Thousand Oaks, CA: Sage. 180 pp., $42.00 (Pbk.). In late winter 2012, a car carrying fo...
Ten-Color flow cytometry reveals distinct patterns of expression of CD124 and CD126 by developing thymocytes

We have developed a 12-parameter/10-color flow cytometric staining method for the simultaneous detection and characterization of 21 mouse thymocyte subpopulations that represent discreet stages of T cell development. To demonstrate the utility of this method, we assessed cytokine receptor expression on mouse thymocyte subsets. These experiments revealed distinct patterns of surface expression of receptors for the cytokines IL-4 and IL-6. The IL-4 receptor α chain (CD124) was highly expressed on the earliest thymocyte subsets, then downregulated prior to T cell receptor β-selection and finally upregulated in the CD4/CD8 double positive cells prior to positive selection. The IL-6 receptor α chain (CD126) showed a different pattern of expression. It was expressed on the most mature subsets within the CD4 and CD8 single positive (SP) compartments and was absent on all other thymocytes with the exception of a very small cKit-CD4-CD8- population. Intracellular staining of SP thymocytes for phosphorylated STAT-1 demonstrated that IL-6 signaling was confined to the most mature SP subsets. This 12-parameter staining methodology uses only commercially available fluorochrome-coupled monoclonal antibodies and therefore could be employed by any investigator with access to a 4-laser flow cytometer. This novel staining scheme allowed us to easily phenotype thymocyte subpopulations that span across development, from the early thymic progenitors (ETPs) to the most mature subsets of the CD4 and CD8 single positive populations.
What is explanation

Explanation is the bread-and-butter activity of any technical communicator. We explain things for a living, but how well can any of us explain the nature of explanation itself? What makes technical explanation different from persuasion or narration? Web-based instructional systems have pushed us away from traditional kinds of paper-bound explanation. In these new realms, anything better than hit-and-miss success requires a clear sense of basic principles. With that in mind, I discuss the basic logic of explanation first proposed by the philosopher C.S. Peirce in the 1870s, and more recently extended by J. Hintikka (1998).
Dissolved hydrogen in the Norwegian Sea: Mesoscale surface variability and deep-water distribution

Abstract The distribution of dissolved hydrogen (H 2 ) was studied during April 1979 in waters along the Iceland-Faroe Islands Ridge and in the Norwegian Sea. Surface water concentrations were well below air equilibrium throughout the region. Three areas (40 × 65 km) were sampled extensively by a surface pumping system allowing contour maps to be prepared with analysis spacings of 4 km. In general, H 2 concentrations were 6 to 7 nl l −1 on the ridge and decreased to 4 nl l −1 on the Voring Plateau. The results for the Norwegian Sea obtained before the spring plankton bloom suggest active consumption of H 2 , presumably by microorganisms, at the sea surface. Apparent net production of H 2 , which predominates in near-surface tropical North Atlantic waters, was not observed anywhere in the region. Vertical distributions showed that H 2 undersaturation persisted at all depths, averaging 4 nl l −1 below 300 m. Iceland-Scotland Overflow Water contained 4.5 nl l −1 . The apparent absence of net H 2 production at high latitudes is unexplained, but may reflect the presence and high activity of chemolithotrophic H 2 bacteria and the relative absence or low activity at high latitudes of H 2 -producing microorganisms such as nitrogen-fixers.
Conversion Technologies: A New Option for MSW Management

Conversion technologies (CTs) utilize thermal or biological processes to convert municipal solid waste (MSW) or Material Recovery Facility (MRF) residuals into useful products, such as electricity, fertilizers, and chemicals. These technologies, such as pyrolysis, gasification, and anaerobic digestion are very different from conventional waste-to-energy (WTE) technologies for MSW. CTs can provide greater efficiency and environmental benefits compared to WTE, and environmental and societal benefits compared to landfilling.Copyright © 2005 by ASME
Conversion of phenyldimethylsilyl to the hydroxyl in the presence of a carbon-carbon double bond

Abstract A simple procedure for the conversion of the phenyldimethylsilyl group to the alcohol in the presence of an alkene has been established.
Co-abstraction of shape collections

We present a co-abstraction method that takes as input a collection of 3D objects, and produces a mutually consistent and individually identity-preserving abstraction of each object. In general, an abstraction is a simpler version of a shape that preserves its main characteristics. We hypothesize, however, that there is no single abstraction of an object. Instead, there is a variety of possible abstractions, and an admissible one can only be chosen conjointly with other objects' abstractions. To this end, we introduce a new approach that hierarchically generates a spectrum of abstractions for each model in a shape collection. Given the spectra, we compute the appropriate abstraction level for each model such that shape simplification and inter-set consistency are collectively maximized, while individual shape identities are preserved.
SU-GG-T-258: Quality Assurance of Plan Parameter Integrity before and during Treatment

Purpose: As a part of initial and ongoing quality assurance, it is necessary to ensure that changes made after the physician approves a plan will not cause a deviation from original intent. Although plan parameters are electronically transferred, few plans are often prepared per case. Past the physician's approval, the specific plan is further modified, and is manually chosen for transfer in our multi‐vendor environment. During treatment, parameters are also modified by therapists and physicians. We created an automated verification system to document (1) proper TP‐RV parameter transfer of the plan, and (2) constancy of treatment parameters on a weekly basis. Method and Materials: A macro (Excel®, Microsoft, Seattle, WA) gathers the TP (Eclipse®, Varian, Palo Alto, CA) and the RV (MOSAIQ®, IMPAC, Sunnyvale, CA) outputs. The macro registers in each modality patient name, ID, prescription, and field parameters. Field parameters include modality, energy, gantry and collimator angles, couch position and angle, aperture definition (cone size or jaw and MLC leaf positions for all segments), wedge angle, and bolus thickness. The Macro then reviews each Eclipse‐MOSAIQ parameter pair. The number of parameter‐pairs ranges from 30 for a single electron field, to as many as 200,000 pairs for an IMRT plan. Basic plan checks are built into the software, such as ensuring the prescription is complete, all parameters are entered and do not exceed machine limits. Results: Gathering both outputs and conducting the review is usually performed within 5 minutes. Since the Eclipse data is already available during the weekly comparison, retrieving the MOSAIQ portion and reviewing is performed in 2 minutes. Conclusion: The algorithm was used for the past year on about 500 patients. The generated report highlights outliers, allowing the reviewer to consider general plan appropriateness, rather than focus on the minutia of each parameter.
The habit planes of zirconium hydride in zirconium and zircaloy

Abstract The habit planes for precipitation of zirconium hydride in Zircaloy-2 and Zircaloy-4 have been determined to be {1017}. The standardization of experimental techniques allows one to make a valid comparison of this result with the {1010} habit plane determined earlier for pure zirconium. Discrepancies between the results of this study and earlier investigations are discussed and possible explanations are proposed.
Non-collinear exchange coupling in Fe/Mn/Fe(0 0 1): insight from scanning tunneling microscopy

Abstract The film growth and morphology of epitaxial Mn films grown on Fe(0 0 1) single-crystal whiskers measured with scanning tunneling microscopy (STM) provides insight into the mechanism of interlayer exchange coupling in Fe/Mn/Fe(0 0 1) trilayers. The proximity model of Slonczewski for exchange coupling through an antiferromagnet predicts that the coupling angle between the ferromagnetic layers will oscillate around a mean value of 90° with an amplitude that is very sensitive to the width of the thickness distribution of the spacer layer. We measure the thickness distribution with the STM and find that the coupling angle variation predicted by the proximity model is qualitatively consistent with the actual coupling angle variations in Fe/Mn/Fe(0 0 1) measured with scanning electron microscopy with polarization analysis (SEMPA). Going beyond the proximity model and allowing for a non-uniform magnetization of the thin Fe overlayer provides an improved explanation of the results. We contrast the behavior of Fe/Mn/Fe(0 0 1), where the proximity model appears applicable, to coupling through antiferro-magnetic Cr in Fe/Cr/Fe(0 0 1), where it is not, and discuss possible reasons for the difference.
ROLE OF CALCIUM AND CALMODULIN IN THE INTERACTION BETWEEN ISLET CELL SECRETION GRANULES AND PLASMA MEMBRANES

The effect of calcium and calmodulin on the binding of islet secretion granules to plasma membrane vesicles was studied. Free Ca++ (10-7 to 10-4 M) produced a concentration-dependent increase in the binding of inside-out,125I-labeled plasma membrane vesicles to secretion granules; maximum stimulation occurred at 10-5 M. By contrast,Ca++ had no effect on binding when either inside-out red blood cell or right-side-out islet plasma membrane vesicles were used. Calmodulin (1 μM), in the presence of 10-4 M Ca++ increased the binding two-fold as compared to Ca++ alone, and trifluoperazina (TFP), an inhibitor of calmodulin, produced a,concentrration-dependent inhibition of the calmodulin effect. TFP also inhibited the binding produced by 10-4M Ca++ in the absence of exogenous calmodulin. These results suggest that Ca++ in the presence of calmodulin modulates the interaction between islet secretion granules and the cytoplasmic surface of the plasma membrane.
Use of a preoperative bleeding questionnaire in pediatric patients who undergo adenotonsillectomy.

OBJECTIVE: To determine the efficacy of a preoperative bleeding questionnaire (POBQ) and coagulation screening in predicting hemorrhage associated with adenotonsillectomy. STUDY DESIGN: Retrospective study. SUBJECTS AND METHODS: Between January 1998 and December 2003, 7730 tonsillectomy and adenotonsillectomy patients were administered the POBQ preoperatively. Further coagulation screening was based on POBQ responses. RESULTS: A total of 232 (3.0%) of 7730 had postoperative bleeding; 184 (3.2%) of 5782 patients who had negative questionnaires bled postoperatively compared with 48 (2.5%) of 1948 patients with positive questionnaires (P = 0.126). Of 1948 patients with positive questionnaires, 141 (7.2%) had abnormal preoperative coagulation screens and 9 (6.4%) of 141 bled; of the 1807 (92.8%) with negative coagulation screens, 39 (2.2%) bled (P = 0.005). CONCLUSION: The POBQ is an effective tool for identifying patients who are at potential risk for post-tonsillectomy bleeding. Patients with both a positive POBQ and coagulation screen had a statistically higher likelihood of postoperative bleeding than other patients. The POBQ allowed the identification of individuals with bleeding disorders to be treated before surgery, likely decreasing the risk of bleeding in these patients.
Electrophysiologic Basis for T Wave Alternans as an Index of Vulnerability to Ventricular Fibrillation

Electrophysiologic Basis for T Wave Alternans. Substantial evidence indicates that T wave alternans is an intrinsic property of ischemic myocardium. The electrophysiologic basis appears to be spatial and temporal heterogeneity of repolarization resulting from changes in action potential morphology rather than in activation sequence. Ischemia-induced changes in postrepolarization refractoriness and depressed electrical restitution of action potential duration have also been implicated. The main underlying ionic basis for T-wave alternans during coronary occlusion appears to be derangements in intracellular cycling of calcium. Accumulation of potassium in the extracellular space adjoining ischemic cells and disruption in electro-genie sodium-calcium exchange may also be involved. In humans, T wave alternans has been observed in Prinzmetal's and classical angina, angioplasty, and bypass graft occlusion. Under these conditions associated with acute myocardial ischemia, alternans is restricted to the ischemic zone, and alternation in action potential morphology is an underlying factor. Recently, repolarization alternans has been shown to be a statistically significant predictor of the results of electro physiologic testing and arrhythmia-free survival in individuals with and without organic heart disease. Collectively, these observations provide a rationale for quantitation of T-wave alternans magnitude for assessment of vulnerability to life-threatening ventricular arrhythmias both in response to and independent of the effects of myocardial ischemia.
Architecture and economic policy

Abstract The Internet is a passion for network technologists and a puzzle for economists. Each discipline needs to understand more of the thinking of the other to advance, but achieving that goal has been slow and difficult. Four papers were developed to further interdisciplinary analysis in the context of the 1995 Telecommunications Policy Research Conference. As explained below, it is hoped that this set of papers will advance telecommunications policy analysis by clarifying the nature of the Internet—in particular, the nature and implications of its architecture— and by framing economic questions based on that characterization, providing a foundation for further research.
BENTHIC MARINE DIATOM ASSOCIATIONS: UPPER FLORIDA BAY (FLORIDA) AND ASSOCIATED SOUNDS1

Models of the diatom associations found in upper Florida Bay and adjoining sounds have been constructed utilizing Q modal factor-vector analysis and ecologic diversity indices (Shannon index, number of species, evenness). Four distinct associations were defined using Q-mode factor-vector analysis. Two associations were epiphytic, occurring on Thalassia testudinum Konig—Association I was characterized by Cocconeis placentula Ehr., Association III by Cylindrotheca closterium (Ehr.) Reim. & Lewin and Cocconeis placentula Ehr. The other two associations were epipelic, occurring on the carbonate mud substratum—Association II was characterized by Cyclotella striata (Kutz.) Grun., Rhopalodia gibberula (Ehr.) O. Muller and Surirella fastuosa (Ehr.) Kutz., Association IV by Fragilaria crotonensis Kitton and Cyclotella striata (Kutz.) Grun. The majority of the 161 species identified were present in both the epiphytic and epipelic assemblages. Only 33 species were restricted to the epiphyton, and 18 species restricted to the epipelon. The epipelic assemblage was significantly more diverse than was the epiphytic assemblage. A general trend of increased diversity away from terrestrial environs toward more open areas of water in both the epipelon and epiphyton was also found.
The Use Of A Real-Time Wave And Weather Measurement Program To Assist In Offshore Operations And Tropical Cyclone Forecasting

This paper describes a program set up by Conoco to improve weather forecasts in the Gulf of Mexico and minimize the risk to the safety of offshore personnel during severe tropical cyclone events. A series of automated wind, wave and weather stations have been deployed in the Gulf to improve the real-time data base available for forecasting. This data is used in support of a hurricane alert program that utilizes the latest state-of-the-art techniques in oceanography and meteorology. Conoco has seen benefits in safer and more efficient evacuations during severe tropical cyclone events, timely return offshore, and a large increase in the amount of real-time information available on these storms.
Uniqueness of limit cycles in a predator-prey model simulating an immune response

We propose a predator-prey model simulating an immune response which is different from Bell's model (Bell 1973). We consider this model as a special case of a general model of Kolmogorov type and discuss the existence and uniqueness of limit cycles in the model.
Magnetic retraction for NOTES transvaginal cholecystectomy

Background Natural orifice translumenal endoscopic surgery (NOTES) has the potential to decrease the burden of an operation on a patient. Limitations of the endoscopic platform require innovative solutions to provide retraction and create an operation comparable with the gold standard, laparoscopic cholecystectomy.
Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of palygorskite

Rietveld refinements using synchrotron powder X-ray diffraction data were used to study the crystal structure and dehydration behavior of pure monoclinic palygorskite samples from Korea and Alaska. The 300 and 100 K palygorskite structures in air compare well with previous models but provide additional details about zeolitic H2O sites and reveal that the Al atoms are ordered into the inner M2 octahedral sites and the Mg cations into the M3 sites at the edges of the tunnels. Real-time, temperature-resolved synchrotron powder X-ray diffraction data and Rietveld refinements were used to investigate the monoclinic palygorskite structure from 300 to 1400 K (in air). Rietveld refinements showed that most of the zeolitic H2O is lost by 425 K, accompanied by a decrease in the unit-cell volume of 1.3%, primarily owing to a decrease in the a unit-cell parameter and an increase in the ? angle. The structurally bound H2O is lost in two stages, at temperature intervals of 475-540 and 580-725 K. Above 825 K in air a portion of the Korean sample transformed to a folded structure; the Alaskan sample folded at 575 K under vacuum. A structure model was refined for the folded structure. At 1015 K for the samplemore » heated in air, ?-quartz diffraction peaks appeared and increased in intensity as heating continued to the maximum temperature. Cristobalite formed above 1050 K, along with a small amount of clinoenstatite, and both phases persisted to the maximum temperature studied.« less
Relationship Between Maternal Exposure to Social Inequalities and Very Low Birth Weight (<1500g, VLBW): An Exploratory Study 1224

For most of this century, it has been recognized that African-Americans have a three-fold greater VLBW rate than whites. However, the mechanism underlying this phenomenon remains one of the most perplexing questions in perinatal epidemiologic research. We performed a two-year hospital-based, case-control study of impoverished African-American mothers to explore the relationship between a woman's perception of exposure to unfair treatment and VLBW. Subjects had no private medical insurance and an annual family income 2500g, non-LBW) infants. Trained African-American interviewers administered a structured questionnaire to both subgroups. There were no differences between cases (n=25) and controls (n=60) with respect to age, education, and marital status. 100% of cases versus 64% of controls felt that racial discrimination was a problem for African-American women, p<0.05. The odds ratios (OR) of VLBW for maternal perception of exposure to racial and gender discrimination that occured during pregnancy were 1.9(0.5-6.6) and 1.7(0.3-10.5), respectively. The Table shows the distribution and OR of maternal exposure to racial discrimination in selected high-risk subgroups.
Appraising the unusual: Framing effects and moderators of uniqueness-seeking and social projection

Abstract In this paper, we examine people’s appraisals of unusual objects and their intuitions about whether others will like those objects. Prior work suggests uniqueness motives (e.g., Need for Uniqueness) affect appraisals, but the effect of these motives on projection of appraisals to others is unclear. Contrary to some prior work, we argue that uniqueness motives do not govern projection of appraisals but rather that individual differences in perceived similarity to a target group do. We also show that perceptions of uniqueness are partly constructed and susceptible to framing, holding all other object properties constant. In two studies, we confirm our predictions about the effects on uniqueness motives and perceived similarity on appraisals and social projection of those appraisals.
OLFACTORY BULBECTOMY IMPEDES SOCIAL BUT NOT PHOTIC REENTRAINMENT OF CIRCADIAN RHYTHMS IN FEMALE OCTODON DEGUS

Recent studies demonstrated that nonphotic (social) cues markedly accelerate reentrainment to large phase shifts of the light-dark (LD) cycle in female Octodon degus and that such changes are likely effected by chemosensory stimuli. This experiment investigated the effects of olfactory bulbectomies on (1) socially facilitated reentrainment rates of circadian rhythms following a 6-h phase advance of the LD cycle, (2) photic reentrainment rates of circadian rhythms following a 6-h advance of the LD cycle, (3) photic entrainment, and (4) the circadian period (τ) of activity rhythms in constant darkness (DD). Olfactory bulbectomies (BX) blocked socially facilitated reentrainment rates but did not alter reentrainment rates of circadian rhythms to photic cues alone. In addition, BX lowered mean daily locomotor activity levels and decreased the amplitude of the activity rhythm in degus housed in entrained (LD 12:12) conditions but did not alter the phase of activity onset or offset, duration (α) of activity, or ...
CLIFFORD-ALGEBRAIC RANDOM WALKS ON THE HYPERCUBE

The n-dimensional hypercube is a simple graph on 2n vertices labeled by binary strings, or words, of length n. Pairs of vertices are adjacent if and only if they differ in exactly one position as binary words; i.e., the Hamming distance between the words is one. A discrete-time random walk is easily defined on the hypercube by “flipping” a randomly selected digit from 0 to 1 or vice-versa at each time step. By associating the words as blades in a Clifford algebra of particular signature, combinatorial properties of the geometric product can be used to represent this random walk as a sequence within the algebra. A closed-form formula is revealed which yields probability distributions on the vertices of the hypercube at any time k ≥ 0 by a formal power series expansion of elements in the algebra. Furthermore, by inducing a walk on a larger Clifford algebra, probabilities of self-avoiding walks and expected first hitting times of specific vertices are recovered. Moreover, because the Clifford algebras used in the current work are canonically isomorphic to fermion algebras, everything appearing here can be rewritten using fermion creation/annihilation operators, making the discussion relevant to quantum mechanics and/or quantum computing.
A Standards-Compliant, Web-based Dynamic Geospatial Data Driven System

Two strategies were developed to efficiently access and use the National Oceanic and Atmospheric Administration (NOAA) Comprehensive Large Array-data Stewardship System (CLASS) data repository with standard programming interfaces and specifications. One strategy, the selective duplication system (SDS), automatically duplicates data for focused areas. Another strategy, asynchronous data serving (ADS), serves data on demand. Both strategies have been implemented for serving data for algorithms using GOES data that detect and track severe weather events. Results showed the role of standards and well-known specifications. Data access delay is reduced. Interoperability is achieved.
RET Gene and Its Implications for Cancer

The RET proto-oncogene encodes a protein receptor tyrosine kinase. RET mutations are associated with the dominantly inherited cancer syndromes multiple endocrine neoplasia (MEN) types 2A and 2B and familial medullary thyroid carcinoma (FMTC). In MEN 2A, MEN 2B, and FMTC, direct detection of RET mutations can be used to identify disease allele carriers prior to the development of clinically evident neoplasms. RET mutations are also associated with sporadic thyroid carcinomas. The effects of RET mutation on protein function have been investigated both in vivo and in vitro, and the study of RET has served to provide insights into the mechanisms of tumorigenesis in general.
Speculative reduction-based scalable redundancy identification

The process of sequential redundancy identification is the cornerstone of sequential synthesis and equivalence checking frameworks. The scalability of the proof obligations inherent in redundancy identification hinges not only upon the ability to cross-assume those redundancies, but also upon the way in which these assumptions are leveraged. In this paper, we study the technique of speculative reduction for efficiently modeling redundancy assumptions. We provide theoretical and experimental evidence to demonstrate that speculative reduction is fundamental to the scalability of the redundancy identification process under various proof techniques. We also propose several techniques to speed up induction-based redundancy identification. Experiments demonstrate the effectiveness of our techniques in enabling substantially faster redundancy identification, up to six orders of magnitude on large designs.
Preoperative Predictors of Persistent Impairments During Stair Ascent and Descent After Total Knee Arthroplasty

Background: Although total knee arthroplasty improves functional mobility in persons with end-stage knee osteoarthritis, many subjects have reported continued difficulty with stair ascent and descent after surgery. The purpose of the present study was to determine preoperative predictors of handrail use during stair ascent and descent following primary unilateral total knee arthroplasty. Methods: One hundred and five adults who were scheduled for unilateral total knee arthroplasty participated in the study. Postoperative handrail use during stair ascent or descent was predicted on the basis of preoperative functional measures. Preoperative age, body mass index, knee strength, knee flexion active range of motion, Knee Outcome Survey scores, time to complete a stair-climbing task, and previous handrail use were entered as covariates into a binary logistic regression. Forward logistic regression was performed to determine which preoperative factors best predicted handrail use at three months and two years after surgery. Handrail use in a control group was also evaluated at baseline and at the time of the two-year follow-up. Results: Prior to surgery, sixty-three of the 105 subjects required a handrail. Two years after surgery, sixty of the 105 subjects required a handrail. In the control group, nineteen of the sixty-four subjects required a handrail at baseline and ten of thirty-one required a handrail at the time of the two-year follow-up. At two years, the preoperative ability to ascend and descend stairs without a handrail was the best predictor of individuals who would not require a handrail after surgery, followed by younger age and greater quadriceps strength. Collectively, these variables correctly predicted the ability of ninety of 105 persons to negotiate stairs without a handrail at two years after surgery (p < 0.001). Conclusions: Younger, stronger patients who do not use a handrail prior to unilateral total knee arthroplasty can expect the best outcomes in terms of ascending and descending stairs following surgery. This information may provide patients with more realistic expectations after surgery and allow them to make more appropriate discharge plans. Level of Evidence: Prognostic Level I. See Instructions to Authors for a complete description of levels of evidence.
Governmental Liability for Breach of Contract

Government contracts are subject to a number of legal rules that have no private sector analogs, and that have received virtually no attention from law and economics scholars. This paper explores these rules from an economic perspective, with special attention to the leading modern case on the subject, United States v. Winstar. The analysis emphasizes a number of differences between governmental and private actors that have important implications for the wisdom of applying conventional breach of contract remedies to the government. These differences afford plausible efficiency justifications, in our view, for many of the most important doctrines governing government contracts. Some of these doctrines help to impede the use of long term contracts to insulate inefficient rent seeking arrangements against subsequent attack, some seem to prevent the government from inefficiently contracting away its ability to respond to new information, and others seem to work a sensible allocation between the government and private contractors of the risk that government may change its policies. Not all doctrines and decisions can be justified in this fashion, however, and we do not mean to claim that the existing body of law is in any sense optimal. Indeed, the Winstar decision itself seems quite mistaken from an economic standpoint. The considerations that we develop have implications for a number of related legal issues. Not all of these implications are developed here, but we do consider modern litigation under the Contract Clause of the United States Constitution, as well as the recent academic debate about the wisdom of retroactive taxation.
A potential apulsatile mode of GnRH release in the male rhesus monkey (Macaca mulatta)

The hypothalamic component of the reproductive axis in vertebrates is comprised of a pulse generator that stimulates the release of GnRH. Several lines of evidence are in agreement that the activity of this pulse generator is intermittent and results in the pulsatile pattern of GnRH and LH release. During a recent investigation of the re-initiation of LH secretion in the agonadal, prepubertal male monkey, we observed a daytime profile of LH secretion, which suggests an apulsatile mode of GnRH release. The first purpose of this study was to describe this observation of apulsatile LH release during the peripubertal transition. Furthermore, we have explored the dependence of this form of LH secretion on GnRH release. Five male rhesus monkeys (Macaca mulatta) were castrated prepubertally and were treated with an intermittent infusion of GnRH to prematurely sensitize the juvenile pituitary to endogenous GnRH release. Alternate daytime (1100‐1800 h) and nighttime (1900‐0200 h) assessments of LH release were performed at 10-day intervals throughout the peripubertal transition with samples taken every 12 min. In a second experiment, four agonadal males which demonstrated an apulsatile profile of LH release were maintained on an infusion of physiological saline and were treated with the GnRH antagonist Nal-Glu (i.m., 500 µg/kg). Circulating levels of LH were determined 22 h after antagonist treatment. In peripubertal animals, circulating levels of LH were similar between morning and evening assessments. However, pulse frequency was significantly lower during the daytime. GnRH antagonist reduced LH levels by 72% and a similar reduction in response to an exogenous GnRH test stimulus occurred. These findings suggest an apulsatile mode of GnRH release.
Depressed Excretion of 6²-Hydroxycortisol in Lead-Toxic Children*

6β-Hydroxycortisol (6βOHF) is a highly polar metabolite of cortisol, probably formed in the endoplasmic reticulum of hepatocytes by cytochrome P-450-dependent microsomal monoxygenases. Lead decreases the activity of cytochrome P-450-dependent microsomal hydroxylases in vivo and in vitro. To examine possible inhibitory effects of lead on 6βOHF metabolism, urinary 6βOHF excretion was measured in 26 children with mild to moderate increases in blood lead concentrations. Children were divided into 2 groups on the basis of their response to the EDTA provocative test. This test was used to assess the size of chelatable and potentially toxic lead stores in such children. Children with elevated urinary lead excretion after an EDTA provocative test, i.e. elevated tissue lead stores, had markedly decreased urinaryexcretion of 6βOHF (178 ± 15 µgj/m2.24 h) compared to children who had negative tests (333 ± 40 µg/m2.24 h; P < 0.01); their urinary cortisol excretion was not different from that of age-matched controls. T...
Nitrogen fixation in an oligotrophic, saline desert lake: Pyramid Lake, Nevada

High rates of nitrogen fixation by a short-lived but dense unialgal bloom of the planktonic blue-green Nodularia spumigena provided 99.5% of the alga's needs and 81% of Pyramid Lake's annual total combined nitrogen input in 1979. The bloom was spatially very heterogeneous. Bloom size, duration, and presumably N/sub 2/ fixation vary from year to year, but in 1979 about 900 t of nitrogenwere fixed in 2 months in this large deep lake. The annual rate of N/sub 2/ fixation was about 2 g m/sup -2/. In this year of low inflow the Truckee River provided 54 t of inorganic nitrogen and 83 t of organic nitrogen. Planktonic N/sub 2/ fixation has not been measured during high inflow years and may have been small relative to river input. Lakewide average heterocyst to vegetative cell (h:c) ratios followed seasonal trends in N/sub 2/ fixation, but synoptic samples showed only a weak relation between h:c and N/sub 2/ fixation. N/sub 2/ fixation was induced by low epilimnetic levels of inorganic nitrogen and ended before lake overturn in the fall. High rates of N/sub 2/ fixation were confined to the upper 5% of the epilimnetic volume and thus occurred only in calm weather whenmore » Nodularia colonies floated to the lake surface. Access to freshly dissolved atmospheric CO/sub 2/ may account for the near-surface dependence, since the lake pH is normally about 9.2. Nodularia will not show the same degree of near-surface dependence in near-neutral lakes or in the ocean.« less
The Low-Energy Unimolecular Reaction Rate Constants for the Gas Phase, Ni+-Mediated Dissociation of the C-C σ Bond in Acetone

The time dependence of the gaseous unimolecular decomposition of the jet-cooled adduct ion, Ni+−OC(CH3)2, was monitored through selective detection of the Ni+CO fragment ion. Various resolved amounts of energy in the range 15600−18800 cm−1 were supplied to initiate the dissociation reaction through absorption of laser photons by the title molecular complex. First-order rate constants, k(E), ranged from 113000 to 55000 s−1 and decreased with decreasing amounts of internal excitation. The energy used to initiate the reaction is well below that required to fragment C−C σ bonds and indicates the necessity of the Ni+ cation to induce bond activation and fragmentation. These measurements are carried out in a unique apparatus and represent the first direct kinetic study of such catalytic type reactions.
Physiological transport properties of cultured retinal microvascular endothelial cell monolayers.

PURPOSE. To characterize baseline transport properties: hydraulic conductivity (Lp), albumin permeability (Pe), and transendothelial electrical resistance (TER) of bovine retinal microvascular endothelial cells (RMEC) in the development of an in vitro model of the blood-retinal barrier (BRB). METHODS. RMEC were grown on porous, polycarbonate filters for determination of the number of days required to achieve minimal transport rates. Lp, Pe, and TER were measured by utilizing a bubble tracking spectrophotometer, by quantifying the diffusional movement of fluorescein isothiocyanate-labeled albumin, and by utilizing a Millipore electrical resistance meter, respectively. RESULTS. Lp decreased significantly from 7.82 ± 0.85 × 10 -7 (mean ± SEM) cm/sec/cm H 2 O at post-plating Day 5 to 1.44 ± 0.26 × 10 -7 cm/sec/cm H 2 O at Day 9. Pe of the monolayer also decreased progressively with days post-plating from 3.44 ± 0.53 × 10 -6 cm/sec at Day 7 to a minimum of 1.95 ± 0.29 × 10 -6 cm/sec at Day 11. Peak TER fluctua...
Cutting Edge: TCR Ligation Triggers Digital Activation of NF-κB

TCR-mediated activation of the transcription factor NF-κB is required for T cell proliferation, survival, and effector differentiation. Although this pathway is the subject of intense study, it is not known whether TCR signaling to NF-κB is digital (switch-like) or analog in nature. Through analysis of the phosphorylation and degradation of IκBα and the nuclear translocation and phosphorylation of the NF-κB subunit RelA, we show that TCR-directed NF-κB activation is digital. Furthermore, digitization occurs well upstream of the IκB kinase complex, as protein kinase C θ translocation to the immunologic synapse and activation-associated aggregation of Bcl10 and Malt1 also demonstrate both digital behavior and high correlation with RelA nuclear translocation. Thus, similar to the TCR-to-MAPK signaling cascade, analog Ag inputs are converted to digital activation outputs to NF-κB at an early step downstream of TCR ligation.
Effects of tube thoracostomy on pleural fluid characteristics in sheep

We studied the pleural inflammatory response to tube thoracostomy by inserting an Argyle 32-Fr tube in the pleural space of 10 anesthetized sheep. An experimental pleural effusion was created by infusion of sterile normal saline (10 ml/kg) into the pleural space, and the animals were allowed to recover. Systemic blood and experimental pleural effusion (EPE) samples were obtained at time 0, 30 min, hourly for 6 h, and at 6-h intervals for a total of 48 h. EPE white cell count rose from 125 +/- 125 to 6,323 +/- 2,268/microliters (SE) at 6 h (P < 0.05) but showed marked variability at 42 and 48 h (P < 0.05), with values ranging from 8,000 to 22,000/microliters. The systemic white cell count rose from 5,195 +/- 914 to 9,640 +/- 1,110/microliters (P < 0.01) within the first 12 h and then remained stable. EPE protein increased from 0 +/- 0 to 3.73 +/- 0.2 g/dl at 48 h (P < 0.05). EPE lactate dehydrogenase rose from 44 +/- 12 IU/l to a peak of 638 +/- 55 IU/l at 24 h (P < 0.05). EPE glucose was significantly lower than serum glucose at 36, 42, and 48 h (P < 0.05). These data indicate that chest tube placement rapidly induces significant pleural inflammation and results in formation of a sterile exudate.