cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantitative bias analysis for study and grant planning

Abstract Purpose Epidemiologists often think about the balance between study error and cost-efficiency in terms of study design and strategies to reduce random error. We less often consider cost-efficiencies in terms of dealing with systematic errors that arise within a study, such as in deciding how to measure study variables and misclassification implications. Methods Given the information used to inform a study size calculation, the expected study data can be simulated during study planning, and the impact of anticipated biases can be estimated using quantitative bias analysis. This would allow investigators and stakeholders to identify areas where better data collection through more valid instruments is critical and where additional investment will not yield strong validity benefits. This could promote better use of study resources and help increase investigators’ chances of funding by demonstrating they have thought through biases and have a plan for mitigating the impact. Results We demonstrate how this would work with a practical example using the relationship between smoking during pregnancy as measured on birth certificates and incident breast cancer. Conclusions We show that although exposure sensitivity would likely be poor, spending more money to get a better smoking measure is unlikely to yield more valid estimates.
Aluminum Oxide Passivating Tunneling Interlayers for Molybdenum Oxide Hole-Selective Contacts

Aluminum oxide thin films fabricated via atomic layer deposition are introduced as passivating tunneling interlayers between hole-selective molybdenum oxide contacts and silicon absorbers. Surface recombination velocity and specific contact resistivity are reported as a function of Al2O3 thickness. The effects of substrate chemical pretreatment, the thermal history of the Al2O3 layers prior to MoOx deposition, and the thermal history of the completed Al2O3/MoOx stacks were also investigated. When an SiOx/Al2O3 passivating stack was incorporated and the completed test structure was annealed at 200 °C, the observed recombination velocities were reduced from ∼10 000 cm/s for an unpassivated (initially hydrogen-terminated) Si/MoOx direct contact to ∼500 cm/s, while maintaining a contact resistivity at or below 0.1 Ω·cm2. The data demonstrate the capability of ultrathin Al2O3 to improve Si/MoOx contact properties and may be of interest in the design of future Si heterojunctions.
How causal information affects decisions

Causality is inherently linked to decision-making, as causes let us better predict the future and intervene to change it by showing which variables have the capacity to affect others. Recent advances in machine learning have made it possible to learn causal models from observational data. While these models have the potential to aid human decisions, it is not yet known whether the output of these algorithms improves decision-making. That is, causal inference methods have been evaluated on their accuracy at uncovering ground truth, but not the utility of such output for human consumption. Simply presenting more information to people may not have the intended effects, particularly when they must combine this information with their existing knowledge and beliefs. While psychological studies have shown that causal models can be used to choose interventions and predict outcomes, that work has not tested structures of the complexity found in machine learning, or how such information is interpreted in the context of existing knowledge. Through experiments on Amazon Mechanical Turk, we study how people use causal information to make everyday decisions about diet, health, and personal finance. Our first experiment, using decisions about maintaining bodyweight, shows that causal information can actually lead to worse decisions than no information at all. In Experiment 2, we test decisions about diabetes management, where some participants have personal domain experience and others do not. We find that individuals without such experience are aided by causal information, while individuals with experience do worse. Finally, our last two experiments probe how prior experience interacts with causal information. We find that while causal information reduces confidence in individuals with prior experience, it has the opposite effect on those without experience. In Experiment 4 we show that our results are not due to an inability to use causal models, and that they may be due to familiarity with a domain rather than actual knowledge. While causal inference can potentially lead to more informed decisions, we find that more work is needed to make causal models useful for the types of decisions found in daily life.
Towards real-time density estimation using vehicle-to-vehicle communications

Abstract Traffic state estimation is a fundamental task of Intelligent Transportation Systems (ITS). Recent advances in sensor technology and emerging computer and vehicular communications paradigms have brought the task of estimating traffic state parameters in real time within reach. Recognizing this, the US-DOT started promoting the Connected Vehicles (CV) initiative. By using wireless connectivity between the vehicles participating in the traffic, the CV initiative aims to promote an increased awareness of real-time traffic conditions and, as a result, to reduce the number and severity of crashes. A number of recent papers have proposed CV-based approaches to estimating traffic state parameters including density and flow. However, virtually all the CV-based approaches for density estimation also rely on communication with stationary detectors and other pre-deployed roadside infrastructure. This assumption is problematic since such infrastructure is often not available. The main contribution of this paper is to propose a simple and easy to implement real-time traffic density estimation method that uses only vehicle-to-vehicle communications and the on-board sensing capabilities of present-day vehicles. In our method, using their on-board devices, vehicles maintain a tally that keeps track of the difference between the number of times other vehicles pass them and the number of times they pass other vehicles. Notice that since vehicles may vary their speed as they please, they may pass and be passed by the same vehicle multiple times and, consequently, maintaining a correct tally is a non-trivial task. We show that the tallies computed by vehicles relate, in an interesting way, to traffic density. We provide a detailed proof of our method using techniques that avoid the use of common simplifications inherent to visual time-space traffic diagrams. Furthermore, we demonstrate the accuracy of our method through extensive simulations using real NGSIM traffic traces along with SUMO-generated synthetic traffic traces.
Structured and Unstructured Contexts in Physical Education: Promoting Activity, Learning and Motivation

The essential role that physical activity (PA) plays in the overall health and well-being of youth is well documented. Children and adolescents in the US repeatedly fail to meet the nationally reco...
CORRELATION OF HANDGRIP STRENGTH WITH ARM ANTHROPOMETRIC VARIABLES IN CRICKETERS

OBJECTIVES: To estimate correlation of handgrip strength with arm anthropometric variables of dominant side. METHODS: This cross-sectional study was conducted on 241 male cricketers from July 2017 to August 2018 in Lahore using convenient sampling. Arm anthropometric variables and handgrip strength of dominant side were measured by standard anthropometric techniques & formulas. Pearson correlation coefficient & linear regression analysis were applied to find out extent of relationship. RESULTS: Mean age of 241 players is 25.19±3.493 years. Out of 241 players, 74 (30%) players were batsmen, 69 (29%) were bowlers, 14 (6%) were wicket keepers and 84 (35%) were all-rounder players. Mean handgrip strength of study participants was 65.783±3.365 kg. Mean values for various anthropometric variables included triceps skinfold thickness (13.807±0.815 mm), subscapular skinfold thickness (16.552±0.763 mm), mid arm circumference (33.398±1.274 cm), arm muscle area (67.381±5.149 cm2), arm muscle girth (29.070±1.116 cm), arm area (88.986±6.643 cm2), arm fat area (21.605±1.836 cm2), and arm fat index (24.281±1.055). Handgrip showed positive correlation with triceps skinfold (r=0.608, p=<0.001), mid-arm circumference (r=0.738, p=<0.001), upper arm muscle area (r=0.694, p=<0.001), upper arm muscle girth (r=0.695, p=<0.001), total arm area (r=0.740, p=<0.001), upper arm fat area (r=0.728, p=<0.001), subscapular skinfold (r=0.215, p=0.001), and arm fat index (r=0.158, p=0.013). CONCLUSION: All the anthropometric variables had a positive significant correlation with handgrip strength. Handgrip strength is standard indicator to achieve target of excellent performance as well as can be made a valuable criterion of selection for cricket & multiple games involving grip.
Improved SARS-CoV-2 Spike Glycoproteins for Pseudotyping Lentiviral Vectors

The spike (S) glycoprotein of SARS-Cov-2 facilitates viral entry into target cells via the cell surface receptor angiotensin-converting enzyme 2 (ACE2). Third generation HIV-1 lentiviral vectors can be pseudotyped to replace the native CD4 tropic envelope protein of the virus and thereby either limit or expand the target cell population. We generated a modified S glycoprotein of SARS-Cov-2 to pseudotype lentiviral vectors which efficiently transduced ACE2-expressing cells with high specificity and contain minimal off-target transduction of ACE-2 negative cells. By utilizing optimized codons, modifying the S cytoplasmic tail domain, and including a mutant form of the spike protein (D614G), we generated an expression plasmid encoding the optimized protein that produces S pseudotyped lentiviral vectors at an infectious titer (TU/mL) 1000-fold higher than the unmodified S protein. S pseudotyped replication-defective lentiviral vectors eliminate the need for biosafety-level-3 laboratories required when developing therapeutics against SARS-CoV-2 with live infectious virus. Furthermore, S pseudotyped vectors with high activity and specificity may be used as tools to understand the development of immunity against SARS-CoV-2, to develop assays of neutralizing antibodies and other agents that block viral binding, and to allow in vivo imaging studies of ACE-2 expressing cells. Funding: This work was supported by a UCLA David Geffen School of Medicine (DGSOM) and Broad Stem Cell Research Center (BSCRC) COVID 19 Research Award. Dr. Lili Yang (UCLA) and Dr. Pin Wang (USC) provided the ACE2 expressing 293T cell line (ACE-293T). Dr. Jocelyn Kim (UCLA) provided the VeroE6 cell lines. The Flow Cytometry Core of the UCLA Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, and the Virology Core of the UCLA Center for AIDS Research (CFAR) (5P30 AI028697) were used to support studies.
Measuring and developing ecological literacy to conserve the critically endangered Mariana Crow

The Mariana crow (Corvus kubaryi), called Aga, is critically endangered and endemic to the Mariana Island of Rota. This study developed and implemented an avian-focused environmental education curr...
Association of acute kidney injury with outcomes in patients undergoing percutaneous left atrial appendage closure

Objectives Using a large nationally representative database, we aimed to examine risk factors for acute kidney injury (AKI) and its association with outcomes in patients undergoing percutaneous left atrial appendage closure (LAAC). Background Previous small-scale studies have reported poor outcomes with AKI following percutaneous LAAC. Methods We queried the Nationwide Readmission Database to identify LAAC procedures performed from 2016 to 2017. Multivariable logistic and linear regression models were used to identify risk factors for AKI and determine the association between AKI and clinical outcomes. The primary outcome of interest was in-hospital mortality. Results Of 20,703 patients who underwent LAAC during the study period, 1,097 (5.3%) had a diagnosis of AKI. Chronic kidney disease, non-elective admission, coagulopathy, weight loss, prior coronary artery disease, heart failure, diabetes mellitus, and anemia were independently associated with an increased risk of AKI after LACC. In patients undergoing LAAC, AKI was associated with an increased risk of in-hospital mortality (adjusted odds ratio [aOR], 16.01; 95% CI, 8.48-30.21), stroke/transient ischemic attack (aOR, 2.50; 95% CI, 1.69-3.70), systemic embolization (aOR, 3.78; 95% CI, 1.64-8.70), bleeding/transfusion (aOR, 1.96; 95% CI, 1.50-2.56), vascular complications (aOR, 3.53; 95% CI, 1.94-6.42), pericardial tamponade requiring intervention (aOR, 6.83; 95% CI, 4.37-10.66), index length of stay (adjusted parameter estimate, 7.46; 95% CI, 7.02-7.92), and 180-day all-cause readmissions (aOR, 1.43; 95% CI, 1.09-1.88). Conclusion AKI in the setting of LAAC is uncommon but is associated with poor clinical outcomes. Further studies are needed to determine if a similar association exists for long-term outcomes.
Physical activity, brain tissue microstructure, and cognition in older adults.

Objective To test whether postmortem MRI captures brain tissue characteristics that mediate the association between physical activity and cognition in older adults. Methods Participants (N = 318) were older adults from the Rush Memory and Aging Project who wore a device to quantify physical activity and also underwent detailed cognitive and motor testing. Following death, cerebral hemispheres underwent MRI to quantify the transverse relaxation rate R2, a metric related to tissue microstructure. For analyses, we reduced the dimensionality of the R2 maps from approximately 500,000 voxels to 30 components using spatial independent component analysis (ICA). Via path analysis, we examined whether these R2 components attenuated the association between physical activity and cognition, controlling for motor abilities and indices of common brain pathologies. Results Two of the 30 R2 components were associated with both total daily physical activity and global cognition assessed proximate to death. We visualized these components by highlighting the clusters of voxels whose R2 values contributed most strongly to each. One of these spatial signatures spanned periventricular white matter and hippocampus, while the other encompassed white matter of the occipital lobe. These two R2 components partially mediated the association between physical activity and cognition, accounting for 12.7% of the relationship (p = .01). This mediation remained evident after controlling for motor abilities and neurodegenerative and vascular brain pathologies. Conclusion The association between physically activity and cognition in older adults is partially accounted for by MRI-based signatures of brain tissue microstructure. Further studies are needed to elucidate the molecular mechanisms underlying this pathway.
Near-Field-Coupled Bondless BAW Oscillators in WCSP Package with 46fs Jitter

This paper presents a 2.5 GHz bulk acoustic wave (BAW) resonator-based oscillator in a wafer chip scale package (WCSP). Electro-Magnetic coupling is used to eliminate rigid galvanic connections between the BAW die and the CMOS oscillator die. The BAW die is attached to the latter with soft die attach, which eliminates stress coupling between the two, resulting in excellent aging performance for the oscillator. The CMOS oscillator circuit is significantly simplified owing to the inductor, which reduces power consumption, enhances oscillator stability, and lowers the phase noise. The presented oscillator achieves best-in-class 46 fs jitter in a sub-1mm3 WCSP package with less than 15 ppm aging over 10years.
Vaccination of Young Dairy Calves against Mannheimia haemolytica and Pasteurella multocida

Enzootic calf pneumonia is responsible for significant economic losses in the dairy industry because of its high morbidity and mortality. An effective vaccine could help reduce these losses. The purpose of our study was to evaluate the efficacy of a commercial Mannheimia haemolytica - Pasteurella multocida vaccine in young dairy calves.
An estimation of expenditure needs for Argentinian provinces: a structural modeling approach

Since 1994 Argentina has failed to honor its Constitution by not passing a law that fully determines intergovernmental fiscal transfers at a national level. This paper uses an innovative structural framework to estimate, and ultimately propose, a new distribution scheme for such transfers. The structural approach allows for the recovery of deep parameters to accurately estimate the expenditure needs for each province, which can then be used to establish the distribution rates that should be assigned to each jurisdiction.
An Analytical Approach of Compensation for Non-Uniform Attenuation and 3D Detector Response in Cardiac SPECT Imaging

Photon attenuation and the non-stationary detector response can reduce the diagnostic accuracy of cardiac SPECT imaging. In this paper, we present a non-iterative approach for compensation of non-uniform attenuation and the 3D detector response in reconstructing cardiac SPECT images. The method involves combining Bellini’s attenuation compensation method using a non-uniform attenuation map, with a frequency distance principle (FDP) based restoration filter to account for the 3D distance-dependent detector response. Simulations using a mathematical cardiac-torso phantom were conducted to obtain projection sets with attenuation only, and attenuation and 3D distance-dependent detector response. “Bulls-eye” polar maps of the reconstructed images showed that using the Bellini method with a nonuniform attenuation map provided quantitatively accurate reconstructions of the myocardium. Applying the combined Bellini/FDP filtering approach to projections degraded by attenuation and distance-dependent blurring also provided quantitatively accurate reconstructions of the myocardium. The Bellini and FDP restoration filtering methods can be implemented with computation times suitable for routine clinical use.
Quality control in the application of flow cytometry to studies of environmentally-induced genetic damage

Flow cytometry (FCM) has been used to demonstrate altered DNA content in fish, reptiles, birds and mammals exposed to radionuclides, PAHs and other contaminants. However, artifacts resulting from sample preparation, handling, variations in instrument parameters or other factors may confound such measurements. Some artifacts resemble genotoxic responses and so could lead to erroneous positive conclusions. As part of ongoing studies of effects of various pollutants on DNA content in fishes, the authors tested sample handling and preparation methods for the induction of artifacts. The authors describe QA/QC methods, including control of staining, conditions, doublet discrimination by comparison of peak versus integral fluorescence, internal DNA standards, and the use of time versus fluorescence plots. Consistent application of these practices is essential to obtain valid measurements of DNA content in environmental samples, and neglect of these can result in poor quality data and the acceptance of incorrect hypotheses.
Heparinlike Species and Inhibition of Proliferation in the Vessel Wall

In the pathogenesis of arteriosclerosis, proliferation of smooth muscle cells (SMC) is a key early step. We have shown that heparin inhibits the growth of SMC both in vivo and in vitro. We have also demonstrated that cultured endothelium secretes a highly antiproliferative heparin species. This antiproliferative activity of heparin has the following characteristics: (1) only certain cell types are sensitive, e.g.. SMC, renal mesangial cells; (2) heparin is by far the most potent of the glycosaminoglycans; (3) anticoagulant and nonanticoagulant heparins are equally effective; and (4) the effect is reversible. The smallest inhibitory fragment of heparin is a pentasaccharide containing a critical 3-O-sulfate. An N-desulfated, re-N-acetylated heparin derivative loses anticoagulant but not antiproliferative activity. Heparin blocks SMC in late Gl, ruling out a direct interaction with platelet-derived growth factor. Other effects of heparin are (1) the induction of secretion of a 35-KDa protein into the medium and (2) the inhibition of nucleoside uptake. Because we have recently found that heparin inhibits the proliferation of rat cervical epithelial cells and that epidermal growth factor (EGF) overcomes this inhibition, we have investigated the effect of various growth factors in reversing the heparin inhibition of VSM. There are species differences in both growth responses to EGF and EGF reversal of heparin inhibition. With heparin-inhibited rat VSM, there is no reversal with EGF (at a dose as high as 50 ng/ml) or with fibroblast growth factor, platelet-derived growth factor, somatomedin C., insulin, and transferrin. With calf VSM, however, EGF (at a dose as low as 0.5 ng/ml) does overcome the heparin inhibition. Although EGF is a potent mitogen for calf VSM, in rat VSM little growth stimulatory effects are found. Interestingly, this correlates with EGF reversibility in the calf and lack of EGF reversibility in the rat. We conclude that EGF reversal of heparin inhibition may not be a universal characteristic of VSM growth regulation.
The Mass Media and Crime Prevention

This chapter outlines mass media crime prevention techniques that attempt to deal directly with the fear of crime as well as the actual crime, across a wide range of societal members. Media presentations affect the fear of crime, feelings of self-confidence in avoiding victimization, criminal behavior, and the adoption of crime prevention precautions. The level and extent of these changes is not uniform across the evaluations. The choice of presentation format and the modes of evaluation are key elements in uncovering positive effects. Any modification in actual crime is difficult to uncover due to the focus on the perceptions of fear and crime instead of on crime itself. Changes in the level of actual crime must rely on the successful modification of these other factors. Once the fear of crime and the level of crime prevention efforts are changed, then the ultimate goal of reduced crime can start to take effect. The chapter also discusses the “Taking a Bite out of Crime” campaign that facilitates attitudinal changes in the groups that are least vulnerable to crime and those already interested in crime prevention issues and other relevant campaigns.
Serine Biosynthesis and Its Regulation in Bacillus subtilis

Cell-free extracts of Bacillus subtilis strains GSY and 168 convert 14 C-phosphoglycerate to 14 C-serine phosphate and 14 C-serine. These reactions indicate a functional phosphorylated pathway for serine biosynthesis in these cells. The addition of serine to the incubation mixture inhibited the formation of both radioactive products. Extracts of mutant strains that require serine for growth lacked the capacity to synthesize serine phosphate, confirming that the phosphorylated pathway was the only functional pathway available for serine synthesis. Serine phosphate phosphatase and phosphoglycerate dehydrogenase activity were demonstrated in cell extracts, and the phosphoglycerate dehydrogenase was shown to be inhibited specifically by l-serine. The extent of serine inhibition increased when the temperature was raised from 25 to 37 C, and the thermal stability of the enzyme was enhanced by the presence of the inhibitor serine or the coenzyme reduced nicotinamide adenine dinucleotide. At 37 C the curve representing the relationship between phosphoglycerate concentration and enzyme velocity was biphasic, and the serine inhibition which was competitive at low substrate concentrations became noncompetitive at higher concentrations.
Two decades of multiagent teamwork research: past, present, and future

This paper discusses some of the recent cooperative multiagent systems work in the TEAMCORE lab at the University of Southern California. Based in part on an invited talk at the CARE 2010 workshop, we highlight how and why execution-time reasoning has been supplementing, or replacing, planning-time reasoning in such systems.
Preliminary experiments with learning agents in an interactive multi-agent systems architecture tradespace exploration tool

One of the main problems of current system design and architecture tools is the communication between the tool and the user and vice-versa. The tools are too opaque, and the users often don't understand their outputs, which results in loss of confidence in the tool. The users are also frustrated because they don't have an effective way of providing their expert knowledge (acquired either in real time or a priori) to the tools, which results in poor performance. This work describes an on-going effort to improve that communication by incorporating an interactive and “transparent” learning agent into a multi-agent tradespace exploration tool. This learning agent mines the current population of architectures for driving features (combination of architectural variables) that appear to drive architectures towards a “good region” or a “bad region” of the tradespace, and shares that information with the user. This information is then used to produce a surrogate classification model based on a decision tree that predicts whether or not an architecture is likely to be in the “good region”. The decision tree model was chosen based on evidence that it is among the most human understandable classification models. The information about driving features is also fed to an adaptive heuristic optimization agent that uses it to intelligently apply “good features” to or remove “bad features” from existing architectures, with the hope of improving the efficiency of the search process. Perhaps most importantly, information about driving features, surrogate models, and heuristics can help the user understand the results of the tool better and gain useful architectural insight, such as dominant features and trade-offs in the architecture space.
287Value of Methicillin Resistant Staphylococcus aureus Nasal Swab Screening for Predicting Invasive Methicillin Resistant Staphylococcus aureus Respiratory Infection in Pediatric Patients with Artificial Airways.

Background: In our 180-bed, free-standing children’s hospital, all patients admitted to intensive care units or from a nursing facility have a GenXpert MRSA nasal screen. This information is routinely used for isolation purposes, but it has increasingly been used to guide antibiotic usage when patients have a suspected infection. Previous studies have demonstrated that patients with positive MRSA screens are at higher risk for MRSA infection. The objective of this study was to evaluate the predictive value of the MRSA screen result for MRSA infection in patients with suspected respiratory infection as tested by bronchoalveolar lavage (BAL) or tracheal aspirate. Methods: All patients admitted from 1/27/09 to 9/17/13 who had both MRSA screening and BAL or tracheal aspirate performed were retrospectively studied. A total of 1336 pairs of screens and cultures were analyzed for correlation of results using descriptive statistics. Results: There were 196 positive MRSA screens (14.7%). Forty-five respiratory cultures were positive for MRSA. Of these 45 positive cultures, 13 had negative MRSA screens, while 32 had positive screens. Statistical analyses demonstrated a positive predictive value for the screen of 16.3% and a negative predictive value of 98.9%. Sensitivity of the screen for a positive respiratory culture was 71%, and specificity was 87.3%. Relative risk of culture-positive MRSA respiratory infection with respect to positive screen result was 14.8. Conclusion: Our study demonstrates that the MRSA nasal screen has a high negative predictive value for MRSA infection in pediatric patients with artificial airways. While patients with a positive screen are at significantly higher risk for culture positive infection, the sensitivity and positive predictive value of a positive screen are relatively low. Since patients with a negative MRSA screen have a lower risk of MRSA respiratory infection, these data could help guide clinicians toward earlier narrowing of empiric antibiotic choices in patients with MRSA screen results and pending respiratory cultures. However, clinical judgment should be used, as 29% of patients in our cohort with a culture positive MRSA respiratory infection had a negative screen. Further study is warranted to clarify the implications of these results. RESULTS • 1336 screen/culture pairs analyzed, 16 eliminated due to discordant results • 188 (14%) MRSA screen positive • 45 (3.4%) MRSA positive cultures • Relative risk for MRSA infection with respect to positive screen 14.8
Adeno-associated Virus Inhibits Human Papillomavirus Type 16: A Viral Interaction Implicated in Cervical Cancer

Human papillomavirus (HPV) infection, in particular that by HPV type 16, is positively associated with cervical/genital cancer. In contrast, human adeno-associated virus (AAV) infection is negatively associated with these same cancers. AAV has also been found to inhibit the oncogenic properties of a variety of DNA viruses, including bovine papillomavirus type 1, a relative of HPV-16. Taken together, these findings suggested the possibility that AAV and HPV-16 might interact, with AAV inhibiting HPV-16′s oncogenic phenotype. Here this hypothesis is addressed using tissue culture assays measuring HPV-16-directed phenotypes. It is found that the cotransfection of AAV type 2 Rep78-positive plasmids resulted in the inhibition of HPV-16 sequence containing plasmids in oncogenic transformation/focus formation, G418-resistant colony formation, and chloramphenicol acetyltransferase expression assays. These data are consistent with the hypothesis that AAV's negative association with cervical cancer is at least partially due to its ability to inhibit HPV-16 expression.
The Leloir pathway: a mechanistic imperative for three enzymes to change the stereochemical configuration of a single carbon in galactose

The biological interconversion of galactose and glucose takes place only by way of the Leloir pathway and requires the three enzymes galactokinase, galactose-1-P uridylyltransferase, and UDP-galactose 4-epimerase. The only biological importance of these enzymes appears to be to provide for the interconversion of galactosyl and glucosyl groups. Galactose mutarotase also participates by producing the galactokinase substrate alpha-D-galactose from its beta-anomer. The galacto/gluco configurational change takes place at the level of the nucleotide sugar by an oxidation/reduction mechanism in the active site of the epimerase NAD+ complex. The nucleotide portion of UDP-galactose and UDP-glucose participates in the epimerization process in two ways: 1) by serving as a binding anchor that allows epimerization to take place at glycosyl-C-4 through weak binding of the sugar, and 2) by inducing a conformational change in the epimerase that destabilizes NAD+ and increases its reactivity toward substrates. Reversible hydride transfer is thereby facilitated between NAD+ and carbon-4 of the weakly bound sugars. The structure of the enzyme reveals many details of the binding of NAD+ and inhibitors at the active site. The essential roles of the kinase and transferase are to attach the UDP group to galactose, allowing for its participation in catalysis by the epimerase. The transferase is a Zn/Fe metalloprotein, in which the metal ions stabilize the structure rather than participating in catalysis. The structure is interesting in that it consists of single beta-sheet with 13 antiparallel strands and 1 parallel strand connected by 6 helices. The mechanism of UMP attachment at the active site of the transferase is a double displacement, with the participation of a covalent UMP-His 166-enzyme intermediate in the Escherichia coli enzyme. The evolution of this mechanism appears to have been guided by the principle of economy in the evolution of binding sites.
A homochiral triple helix constructed from an axially chiral bipyridine

A homochiral triple helix was self-assembled from an axially chiral bipyridine and a linear metal-connecting point, which further assembles into a 2D network via infinite π⋯π stacking interactions and acts as a host for the inclusion of guest molecules.
Effect of allergen challenge on the percentage of natural killer T cells in patients with atopic asthma.

Background Invariant natural killer T (iNKT) cells produce cytokines that can influence the immune response to infection or allergen. Controversy surrounds their role in exacerbations of human atopic asthma. Objectives To determine the effect of allergen challenge on iNKT cells' mobilization to the airways and blood and to establish the relationship between airway iNKT cells and bronchial sensitivity to methacholine and allergen in patients with atopic asthma. Methods We performed flow cytometry analysis for the iNKT cell receptor Vα24 and Vβ11 on bronchoalveolar lavage (BAL) cells at baseline and 24 hours after segmental antigen challenge (SAC) (n = 8) and on peripheral blood mononuclear cells (PBMCs) at baseline and 6 to 7 hours after inhaled allergen (n = 10). Challenges were performed using standardized protein allergens to which the participants were sensitive. Results The number of BAL eosinophils increased 24 hours after SAC. The low mean (SEM) baseline percentage of iNKT cells in the population of BAL CD4 + T cells remained unchanged 24 hours after SAC (0.035% [0.01%] vs 0.049% [0.02%]; n=8; P = .50). Likewise, the mean (SEM) percentage of iNKT cells in PBMCs was unchanged after inhaled allergen provocation (0.068% [0.033%] vs 0.057% [0.026%]; n=10; P = .10). No correlation was found between iNKT cells in BAL and the sensitivity to inhaled methacholine or allergen. Conclusions The percentages of both BAL and peripheral blood iNKT cells did not increase during allergen provoked asthmatic responses. Determination of iNKT cells in airway biopsy specimens would allow conclusively ruling against mobilization of iNKT cells in allergen-induced asthma exacerbation in humans.
Fas- and Tumor Necrosis Factor-induced Apoptosis Is Inhibited by the Poxvirus crmA Gene Product

crmA is a cowpox virus gene that encodes a protease inhibitor of the serpin family. The only reported target for the CrmA protein is the cysteine protease interleukin-1β converting enzyme (ICE). ICE, by virtue of its homology to the Caenorhabditis elegans cell death protein Ced-3, has been suggested to play a fundamentally important role in mammalian apoptosis. We hypothesized that a function of crmA may be to inhibit cell death, since a major mechanism of viral clearance is the immune system-mediated induction of apoptosis of infected cells. The tumor necrosis factor receptor and the Fas antigen are two cytokine receptors which, by engaging and activating the death pathway, can eliminate virus-infected cells. Remarkably, crmA was found to be an exceptionally potent inhibitor of apoptosis induced by both these receptors, capable of blocking the cell death program even at pharmacological doses of the death stimulus. Therefore, an important new function for crmA is the inhibition of cytokine-induced apoptosis. Further, the data suggest that a protease, either ICE or a related crmA-inhibitable protein, is a component of the Fas- and tumor necrosis factor-induced cell death pathways.
Heavy Metals in Eight 1965 Cores from the Novaya Zemlya Trough, Kara Sea, Russian Arctic

Abstract The concentration and distribution of 18 chemical elements were determined in 86 samples from eight sediment cores, 89–131 cm long, collected during 1965 along a 650 km traverse in the Novaya Zemlya Trough, Kara Sea, Russian Arctic. These include potentially toxic elements followed by the Arctic monitoring and assessment program (AMAP) (e.g., As, Cr, Hg, Pb) and elements that may be related to the fine size minerals in these cores (e.g., Al, K, Mg). Arsenic and Hg had high concentrations (to 212 ppm – baseline 20 ppm, and to 875 ppb – baseline 338 ppb, respectively) in upper sections of cores. This suggests possible anthropogenic input in the Kara Sea before 1965. In contrast, most of the metals analysed had baseline contents throughout the cores. High As values in the sediments probably reflect a combination of diagenetic mobilization from depth to surface/near-surface sediments and input from human activities such as dumped military materials in the trough, mining and smelting effluents and emissions, and the burning of fossil fuel (especially coal). High Hg contents cannot be the result of the diagenetic path followed by As and may reflect an anthropogenic addition of Hg to high natural baseline values from atmospheric deposition of industrial emissions as well as from decomposition of dumped wastes (e.g., lewisite) and naval reactor coolant discharged into the sea. Arsenic and Hg discharged into the southern Kara Sea from Siberia and the Novaya Zemlya archipelago move with oceanic currents and ice-floes as suspensates or adhered particulates for deposition in the trough. Arsenic is likely mobilized in particulates as the arsenate species sorbed to ferric oxy/hydroxides whereas Hg can be mobilized in organisms as the biomethylated form or Hg species (e.g., Hg 2+ , HgCl 4 2− ) sorbed onto organic and/or inorganic (clay mineral) particulates. High concentrations of Mn and Mo in upper core sediments result from post-depositional mobilization from reduced deeper sediments to oxic surface sediments.
Silviculture and biology of short-rotation woody crops in temperate regions: then and now.

Abstract Although its roots are in antiquity, the current concept of short-rotation woody crops (SRWC) for fiber and energy evolved scientifically from pioneering tree breeding work begun in the early 20th century. A natural outgrowth of this work was the culture of fast-growing trees on rotations of 1–15 years. Close-spaced tree culture received further impetus with the introduction of the “silage sycamore” concept in the southeastern US in the mid-1960s and the OPEC oil embargo in 1973, leading to statistically designed trials at numerous locations in North America, Europe, and Scandanavia. Early silvicultural research focused on spacing and species trials, propagation methods, site preparation, weed management, nutrition, growth, and yield. Because these trials were based on small plots, and the importance of pest depredations or site variation were not fully recognized, early biomass yield predictions tended to be overly optimistic. Soon physiologists and ecologists began to unravel the biological characteristics of SRWC plantations and their responses to environment. Knowledge of the influence and diversity of pests—insects, diseases, and animals—provided a necessary reality check. Many hardwood tree species and a few conifers have been evaluated over the years for SRWC in temperate regions of the world. Clones of Populus and Salix, however, became the dominant plantation material because of their inherently rapid growth and ease of propagation by hardwood cuttings. Among conifers, loblolly pine (Pinus taeda) also shows promise. Because genetic variation is readily exploitable in the dominant SRWC taxa, strongly focused breeding programs began to provide highly productive genotypes and seed sources in the last decades of the 20th century. A new plateau, with significant practical potential, was reached in the late 20th century when biotechnological methods were applied to tree taxa. Recently, the DNA in the Populus genome was sequenced. Thus, the few current commercial applications of SRWC rest on a substantial base of silvicultural and biological knowledge.
LRP6 Protein Regulates Low Density Lipoprotein (LDL) Receptor-mediated LDL Uptake

Genetic variations in LRP6 gene are associated with high serum LDL cholesterol levels. We have previously shown that LDL clearance in peripheral B-lymphocytes of the LRP6R611C mutation carriers is significantly impaired. In this study we have examined the role of wild type LRP6 (LRP6WT) and LRP6R611C in LDL receptor (LDLR)-mediated LDL uptake. LDL binding and uptake were increased when LRP6WT was overexpressed and modestly reduced when it was knocked down in LDLR-deficient CHO (ldlA7) cells. These findings implicated LRP6 in LDLR-independent cellular LDL binding and uptake. However, LRP6 knockdown in wild type CHO cells resulted in a much greater decline in LDL binding and uptake compared with CHO-ldlA7 cells, suggesting impaired function of the LDLR. LDLR internalization was severely diminished when LRP6 was knocked down and was restored after LRP6 was reintroduced. Further analysis revealed that LRP6WT forms a complex with LDLR, clathrin, and ARH and undergoes a clathrin-mediated internalization after stimulation with LDL. LDLR and LRP6 internalizations as well as LDL uptake were all impaired in CHO-k1 cells expressing LRP6R611C. These studies identify LRP6 as a critical modulator of receptor-mediated LDL endocytosis and introduce a mechanism by which variation in LRP6 may contribute to high serum LDL levels.
Facilitative effects of punishment on aggressive behavior in the Siamese fighting fish

Male Siamese fighting fish (Betta splendens) were reinforced for swimming through an aperture by a mirror presentation which released an innate aggressive display. Moderately intense shock-punishment of the operant response increased the vigor of the display and, temporarily, the rates of the operant response. Gradual decreases in rate within and across nonpunished sessions reflected short-term and long-term habituation to the mirror image.
Electroluminescence in CdSe crystals in acoustoelectric current oscillation

Abstract Radiative recombination in low resistivity CdSe single crystals has been observed when the drift velocity of free electrons reaches or exceeds the velocity of sound. A high electric field, (≈ 5 × 10 3 V/cm) domain associated with a pocket of amplified phonons moves across the sample. Deep impurity levels in the gap are ionized by the moving domain. The emission is confined to two peaks with maxima at 0.70 μ m and 0.86 μ m. The emission is attributed to recombination of free electrons with holes bound to acceptors and recombination at an unknown impurity respectively. The 0.70 μ m peak is shifted to shorter wavelengths by the conditions which exist within the domain. We find that the 0.70 μ m emission source moves across the sample as the domain does and the spatial widths of the emission and high field domains are approximately equal. The 0.86 μ m emission comes from behind the domain.
Precision measurement of dipole moments and other spectral constants of normal and deuterated methyl fluoride and methyl cyanide

Abstract From high precision measurements of first- and second-order Stark effects on both ΔM = 0 and ΔM = ±1 transitions, the molecular dipole moments of normal and deuterated methyl fluoride and methyl cyanide have been obtained as follows: for CH3F, μ = 1.8572 ± 0.0010 D; for CD3F, μ = 1.8682 ± 0.0010 D; for CH3CN, μ = 3.913 ± 0.002 D; for CD3CN, μ = 3.919 ± 0.004. A remeasurement of zero-field lines yields more accurate values of the spectral constants for three of these. They are: for CH3F, B0 = 25 536.148 ± 0.005 Mc/sec, DJ = 60.4 ± 0.10 kc/sec, DJK = 439.26 ± 0.05 kc/sec; for CD3F, B0 = 20 449.854 ± 0.012 Mc/sec, DJ = 34.2±0.4 kc/sec, DJK = 221.7 ± 0.9 kc/sec; for CD3CN, B0 = 7858.117 ± 0.008 Mc/sec, DJ = 4.64 ± 0.06 kc/sec, DJK = 110.59 ± 0.10 kc/sec.
Proteins mask gangliosides in milk fat globule and erythrocyte membranes

Abstract Ganglioside in the membrane of erythrocytes and the fat globules of cow's milk were not degraded by neuraminidase treatment at pH 5.2 or 7.4. Removal of portions of the membrane protein by treatment with trypsin or by extraction with a solution of EDTA and 2-mercaptoethanol rendered these membrane-associated gangliosides accessible to neuraminidase attack. After trypsin treatment under conditions where the membranes are impermeant to this enzyme, gangliosides were exposed to neuraminidase. The results suggest that the carbohydrate groups of the gangliosides of bovine erythrocytes and milk fat globules are located primarily on the environmental face of the membrane and are shielded from neuraminidase attack by membrane proteins.
The Retention of Indigenous Students in Higher Education: Historical Issues, Federal Policy, and Indigenous Resilience.

This article focuses on answering two main questions: Why is this phenomenon occurring for Indigenous students in higher education and what are effective solutions for the retention and success of ...
(Mis)Quoting Dante: Early Epic Intertextuality in Huon d’Auvergne

Huon d’Auvergne, a Franco-Italian chanson de geste dated from 1341 to 1441 in its manuscripts, is the first text known to incorporate Dante’s Commedia into its plot. The manuscripts, present in the Gonzaga library inventory as well as others, demonstrate the intertextuality of the late romance epic: a wandering hero on a personal mission encounters trials calling for physical and psychological prowess. However, the visit to hell is not just an imitation of Dante; the trip contains citations from Dante subtly revised and collocated according the redactor’s interest, punishing specifically those who did badly by his hero and those who betray the chanson de geste value system in which he writes.
Treatment of an Iatrogenic Petrous Carotid Artery Pseudoaneurysm with a Symbiot Covered Stent: Technical Case Report

OBJECTIVE AND IMPORTANCE Surgery involving the middle ear or the temporal bone may cause an injury to the petrous carotid artery resulting in a pseudoaneurysm. Conventional treatment of such pseudoaneurysms has ranged from carotid occlusion to conservative management. The use of a balloon-expandable
Numerical Instability due to Varying Time Steps in Explicit Wave Propagation and Mechanics Calculations

Explicit central-difference time integration is frequently used to solve the wave equation, and the classical criterion for numerical stability is the Courant?Friedrichs?Lewy condition. Similarly, explicit integration of a spring-mass mechanical system has a stability condition. These conditions are derived under the assumption of constant time steps. This paper demonstrates the new and perhaps surprising result that numerical instability may occur when time steps vary, even though all steps are substantially less than the constant step criterion.
Creating object-oriented designs from legacy FORTRAN code

The majority of scientific and engineering software systems currently in use are on average 10 to 15 years old. They have undergone extensive maintenance and, therefore, suffer from such problems as inaccurate or missing documentation, poorly structured code, and low modular cohesion. Moreover, the mere age of such systems has prohibited their realization of such recent innovations as object orientation. This paper addresses these concerns in the context of reverse engineering. It discusses the development of a method to identify objects in legacy systems, specifically those coded in the imperative language, FORTRAN-77. Algorithms that use a greedy approach to object extraction are presented. Viewing the subroutine as the unit of functionality, the attributes of candidate objects are extracted from two areas: parameters and global variables. Because FORTRAN-77 uses the COMMON block as the mechanism for realizing global variables, additional algorithms are presented to handle the resulting concerns. Using a modification of the program slicing concept introduced by Weiser in 1984, methods are defined for each set of attributes. The combination of the extracted attributes and methods forms the set of candidate objects. Throughout the paper, an example is used to illustrate the methodology.