cssi/SciSciGPT-SciSciNet huggingface dataset:
Protecting computers and people from viruses

The COVID-19 pandemic highlights the virus analogy that gave rise to the use of the word "virus" from biology, to label a malicious program that attacks computer systems The situation moves us to look into that, as another way to compare nature and artifact, and as an excuse to raise more abstract questions We are moved also to stipulate that our mastery of both the biological and computational forms is shallow, and to invite other, better observations to follow See Apvrille and Guillaume for greater depth and intriguing crossover speculation, Weis for yet more intriguing comparison, and Wenliang Du's website for detailed virus examples, which constitute dramatic reading for coders We distinguish computer viruses from computer worms by the profligate scale of replication, viruses generating a broadcast of copies rather than a chain of copies The obvious points of analogy across both types of virus include that viruses are tiny, invading a host much greater in size and complexity, without an overt signal, and that viruses disrupt some process in the host
Abstract 14649: Chloride Channel Calcium-activated-1 Reduces Mouse Abdominal Aortic Aneurysm by Blocking Macrophage Migration Inhibitory Factor Activity in Macrophage Activation

Introduction: Human chloride channel calcium-activated-1 (CLCA1) protein is a secretory protein that goblet cells from trachea epithelium express abundantly where it participates in hypersecretory ...
Reviewing applications of structural and functional MRI for bipolar disorder

Bipolar disorders (BDs) represent one of the leading causes of disability and morbidity globally. The use of functional magnetic resonance imaging (fMRI) is being increasingly studied as a tool to improve the diagnosis and treatment of BDs. While morphological biomarkers can be identified through the use of structural magnetic resonance imaging (sMRI), recent studies have demonstrated that varying degrees of both structural and functional impairments indicate differing bipolar subtypes. Within fMRI, resting-state fMRI has specifically drawn increased interest for its capability to detect different neuronal activation patterns compared to task-based fMRI. This study aims to review recently published literature regarding the use of fMRI to investigate structural-functional relationships in BD diagnosis and specifically resting-state fMRI to provide an opinion on fMRI's modern clinical application. All sources in this literature review were collected through searches on both PubMed and Google Scholar databases for terms such as 'resting-state fMRI' and 'functional neuroimaging biomarkers of bipolar disorder'. While there are promising results supporting the use of fMRI for improving differential accuracy and establishing clinically relevant biomarkers, additional evidence will be required before fMRI is considered a dependable component of the overall BD diagnostic process.
Laboratory Diagnosis of Syphilis

The laboratory diagnosis of syphilis has relied, in large part, upon serologic methods for over 100 years (1). The causative organism, Treponema pallidum, is not amenable to in vitro culture, and antigen detection and nucleic acid amplification techniques have not become routinely used. While many of the serologic methods in use now have been in use for decades, their application, specifically the standard testing algorithm, is changing. In order to understand the interpretation of alternative testing algorithms, a thorough understanding of test characteristics is necessary. This chapter will review serologic tests for syphilis and their interpretation when they are applied to adults with and without HIV infection and to children.
The Effects of Variable Velocity of Rupture Propagation on Fault’s Directivity Pulses

Unilateral rupture propagation along earthquake faults results in asymmetric radiation in and opposite to the direction of rupture travel, known as forward and backward directivity. Correct simulation of fault directivity pulses in ground velocity has engineering significance. Forward velocity pulses are typically recognized as short bursts of energy with large amplitude, compared to elongated and much weaker backward wave trains. A classic model of such behavior is the line source in the far field, undergoing rupture propagation with constant speed. In reality, earthquake ruptures can be reasonably expected to travel in a variable, often irregular, manner. Simulation of the distinctions introduced by the variable rupture velocity into the characteristic features of directivity should not only involve the line source but also finite sources in the near field. The differences with the case of constant rupture velocity are threefold. First, sharp amplitude contrast between the velocity pulses in the forward and reverse directions is substantially subdued by the variable fracture speed. Second, complex ruptures result in the longer duration of radiation in both directions. Third, unlike the relatively simple radiation pulses in the scenario of constant velocity, complexity in the rupture travel time creates multiple pulses of both forward and reverse directivity. Randomization of rupture velocity nearly erases the differences in the spectral content of radiation in the forward and backward directions. Well known features of fault directivity appear to be artifacts of the constant-velocity assumption and the resulting orderly interference. The complexity that randomization introduces into the directivity pulses is gradually reduced with lesser randomness. Since irregularity in the rupture travel time should be viewed as the norm rather than an exception, correct simulation of fault directivity must involve variable velocity of rupture propagation.
Anger and Attention Problems as Mechanisms Linking Maltreatment Subtypes and Witnessed Violence to Social Functioning Among Children in Out-of-Home Care:

Research has consistently shown that child maltreatment and witnessed violence lead to disrupted patterns of social functioning, yet the mechanisms underlying these pathways remain unclear. This cr...
Arguments about Arguments: Systematic, Critical, and Historical Essays In Logical Theory

Part I. Theorizing about Reasoning and Argument: 1. Informal logic and the theory of reasoning 2. An historical approach to the study of argumentation 3. Methodological problems in empirical logic 4. Two empirical approaches to the study of reasoning 5. Critical thinking, critical reasoning, and methodological reflection Part II. Fallacies and Asymmetries: 6. Fallacies and the evaluation of reasoning 7. Six types of fallaciousness 8. Asymmetries in argumentation and evaluation 9. The positive versus the negative evaluation of arguments Part III. Critiques: 10. Siegel on critical thinking 11. Introduction and intuition in the normative study of reasoning 12. Logic, politics, and Gramsci 13. The dialectical approach to interpretation and evaluation 14. The Port-royal logic's theory of argument 15. A critique of the dialectical approach 16. Valid Ad Hominem arguments in philosophy 17 Dialectics, evaluation, and argument Part IV. Historical Analyses: 18. The concept of Ad Hominen argument in Galileo and Locke 19. Newton's third rule of philosophizing 20. Logic and rhetoric in Lavoisier's sealed note 21. The concept of judgment and Huygens' theory of gravity 22. Empiricism, judgment, and argument 23. Criticism, reasoning, and judgment in science.
Should Licensure be Required for Faculty Who Teach Direct Practice Courses? No!

The enactment of a standard requiring licensure for teachers of practice courses would be impractical and unfair. It would be redundant since adequate measures of academic accountability are already in place, and unnecessary since teaching is not the same thing as practice. The problem that requiring licensure is designed to solve is the wrong problem. Finally, enactment would signal a step backward in any effort to improve prac tice and practice teaching.
Head Pose Estimation for Video-Conferencing with Multiple Cameras and Microphones

An automatic video-conferencing system is proposed which employs acoustic source localization, video face tracking and pose estimation. The audio portion of the system provides the initial localization of the talkers and the video component tracks the talkers by utilizing source motion, contour geometry, color data, and simple facial features. Decisions involving which camera to use are based on an estimate of the head's orientation. This head pose estimation is achieved using a very general head model which employs hairline features and a learned network classificaion procedure powered by Support Vector Machines. The procedure is capable of accurately evaluating head orientations over a complete 360 degree interval. By relying on a facial criterion that is easily extracted from video images acquired across a range of lighting and zooming conditions, the estimator is designed to be effective in practical situtaions such as those encounted in video conferencing or surveillance scenarios.
Facile Redox Interconversion of 6,11‐Diphenyldibenzo[b,f][1,4]diazocine and 2‐(2‐Aminophenyl)‐1,3‐diphenylisoindole: Reversible SET Ring Contraction and Expansion Processes

In our continuing attempts to convert tub-shaped dibenzo[1,4]diazocines or dibenzo[1,5]diazocines into necessarily planar Huckel aromatic ten-π-electron dianions or dihydro derivatives of the central diazocine ring, we have added requisite electrons by Na or Li metal in THF. Subsequent hydrolysis yielded no evidence for the formation of such Huckel aromatic products but in each case a profound rearrangement of the tricyclic diazocine had instead occurred. In the present study we have attempted to form the unknown aromatic 6,11-diphenyldibenzo[b,f][5,12]-dihydro[1,4]diazocine at 25 °C by such a straightforward addition of two electrons to 6,11-diphenyldibenzo[b,f][1,4]diazocine. We were encouraged by the prior reduction of the unsubstituted [1,4]diazocine to 1,4-dihydro-[1,4]diazocine, which by X-ray and 1H NMR evidence displays aromatic-like properties. However, this diphenyldibenzo[1,4]-diazocine upon reduction underwent instead an unusual, serendipitous rearrangement to yield quantitatively 2-(2-aminophenyl)-1,3-diphenylisoindole. Then in a purposive search for other reductants capable of reductively rearranging this [1,4]diazocine to its corresponding isoindole, we discovered three other reductants, namely o-diaminobenzene, titanium(II) salts, and concentrated aqueous hydriodic acid with visible light. Conversely, again in a serendipitous observation, it was found that O2 in CHCl3 with visible light could readily convert the isoindole in an oxidative rearrangement back into the [1,4]diazocine. A purposive method for achieving this oxidative rearrangement was then found to be treatment with DDQ. General mechanistic pathways are proposed via SET intermediates for both redox interconversions.
Phosphodiesterase Inhibitors, Congestive Heart Failure, and Sudden Death: Time for Re-Evaluation

A 42-year-old diabetic man was admitted with systolic heart failure and pulmonary hypertension being treated with sildenafil for the previous year. With an increase in creatinine, he experienced 3 episodes of ventricular tachycardia and ventricular fibrillation. Withdrawal of the phosphodiesterase (PDE) inhibitor resulted in no further episodes of dysrhythmias. The basic pharmacology of PDE inhibitors is presented and the use of PDE-3 inhibitors for the treatment of heart failure causing an increase in sudden death is also reviewed. There have been several cases of sudden death associated with sildenafil use and with its increasing use in patients with severe pulmonary hypertension and decompensated heart failure. The authors also reviewed the electrophysiologic effects of PDE-5 inhibitors associated with their use. The crossover between PDE-3 and PDE-5 inhibitors is also discussed and caution is urged when contemplating the use of PDE-5 inhibitors in patients with systolic heart failure and pulmonary hypertension.
1-Bromo­methyl-4-aza-1-azoniabicyclo­[2.2.2]octane bromide

The title compound, C7H14BrN2+·Br−, was prepared by nucleophilic substitution of DABCO (systematic name: 1,4-diaza­bicyclo­[2.2.2]octa­ne) with dibromo­methane in acetone. The structure features Br⋯H close contacts (2.79 and 2.90 A) as well as a weak bromine–bromide inter­action [3.6625 (6) A].
On the dynamics of polarization mode dispersion

The PMD dynamics in aerial fiber can be well modeled by highly mode coupled wave-plates via the mode coupling angle fluctuation described by a Gaussian probability transition function. The RMS mode orientation angle undergoes a Brownian motion in aerial fiber. The fitting parameter K is easily measured and used as a single quantity to describe the dynamical nature of a field optical fiber with sufficient statistics. This allows industry to measure and quantify SOP and PMD correlation when field testing optical fibers. We find the K value for aerial fiber is about an order of magnitude larger than that of the buried fiber.
Use of intracardiac echocardiography to guide percutaneous transluminal mitral commissurotomy: A 20-patient case series

Objectives To report the efficacy and safety of the use adjunctive intracardiac echocardiography (ICE) during percutaneous transluminal mitral commissurotomy (PTMC) in patients without transesophageal echocardiography (TEE). Background Patients with mitral stenosis are at a high risk of developing a left atrial (LA) thrombus. Traditionally, TEE has been used prior to PTMC to identify the presence of LA thrombi. There have been no reports of the use of ICE to assess the LA for thrombi prior to PTMC. Methods We retrospectively reviewed 20 patients who underwent ICE prior to PTMC. All PTMC procedures were performed via the antegrade transvenous approach using an Inoue balloon. Initially, ICE was used from the right atrium to confirm the absence of a thrombus on the left side of the septum and was subsequently used to guide the transseptal puncture. Following these procedures, the ICE was advanced into the LA through a transseptal sheath to visualize the LAA. Results Visualization of the thrombus/spontaneous echo contrast was considered to be diagnostic in all cases. Seventy percent of the patients were discharged on day after the procedure. No patients required intubation during the procedure, and there were no complications that could be attributed to the use of ICE. At six months after the PTMC, the incidence of stroke was zero. Conclusions ICE-guided PTMC offers excellent visualization of the LA and the LAA with satisfactory clinical outcomes and low risk. As a part of the PTMC procedure, ICE safely provides a valid alternative to a separate TEE procedure. © 2015 Wiley Periodicals, Inc.
COLLUSIVE EQUILIBRIUM IN COURNOT OLIGOPOLIES WITH UNKNOWN COSTS

The article studies collusive equilibria in an infinitely repeated Cournot oligopoly with unknown costs. I look at collusive pooled Perfect Bayesian equilibria and separating equilibria either with signaling or with communication. In the separating equilibria with signaling the firms play the strictly separating Bayesian Nash equilibrium in period 1 and produce the optimal incentive compatible collusive quantity vector from period 2 onwards. In the separating equilibrium with communication the optimal incentive compatible quantity vector is produced from period 1 onwards. Among these, the optimal separating equilibrium with communication gives the highest expected discounted joint profits.
Mutant α-synuclein and aging reduce neurogenesis in the acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson’s disease

Neurogenesis, the production of new neurons from less differentiated precursor cells, normally occurs in adult brains in the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone of the hippocampal dentate gyrus. Neurogenesis declines with aging. In previous studies, neurogenesis was stimulated by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) in young animals. In this study, we examined the effect of acute MPTP administration and mutant α-synuclein A53T on neurogenesis and migration of newborn neurons in the aged (23-month) vs. young (2-month) rodent brain. Cell proliferation and neurogenesis were assessed via bromodeoxyuridine labeling and immunostaining for cell type-specific markers. In the aged brain, neural precursor cells in the rostral SVZ retained the capacity for proliferation and migration in response to MPTP-induced Parkinsonism, although the response is less robust than in younger animals. Furthermore, in transgenic mice that overexpress mutant α-synuclein (A53T), brains examined day 21 after MPTP administration showed markedly decreased olfactory bulb and substantia nigra neurogenesis. Our data suggest that in addition to aging effects associated with decline in the number of newly generated cells, mutant α-synuclein reduces MPTP-induced neurogenesis. This could provide a novel therapeutic target for chronic brain repair in this condition.
Stereoselective synthesis of meso-1,5-cyclodecadiynes.

Reduction of Co2(CO)6-stabilized bis-propargyl cations with cobaltocene occurs with high meso-diastereoselectivity (up to 97%), affording, upon decomplexation, meso-1,5-cyclodecadiynes, otherwise hardly accessible.
A new chronology for the age of Appalachian erosional surfaces determined by cosmogenic nuclides in cave sediments

The relative chronology of landscape evolution across the unglaciated Appalachian plateaus of Kentucky and Tennessee is well documented. For more than a century, geomorphologists have carefully mapped and correlated upland erosional surfaces inset by wide-valley straths and smaller terraces. Constraining the timing of river incision into the Appalachian uplands was difficult in the past due to unsuitable dating methods and poorly preserved surface materials. Today, burial dating using the differential decay of cosmogenic 26Al and 10Be in clastic cave sediments reveals more than five million years of landscape evolution preserved underground. Multilevel caves linked hydrologically to the incision history of the Cumberland River contain in situ sediments equivalent to fluvial deposits found scattered across the Eastern Highland Rim erosional surface. Cave sediments correlate with: (1) thick Lafayette-type gravels on the Eastern Highland Rim deposited between c. 5·7 and c. 3·5 Ma; (2) initial incision of the Cumberland River into the Eastern Highland Rim after c. 3·5 Ma; (3) formation of the Parker strath between c. 3·5 Ma and c. 2·0 Ma; (4) incision into the Parker strath at c. 2 Ma; (5) formation of a major terrace between c. 2·0 Ma and c. 1·5 Ma; (6) shorter cycles of accelerated incision and base level stability beginning at c. 1·5 Ma; and (7) regional aggradation at c. 0·85 Ma. Initial incision into the Appalachian uplands is interpreted as a response to eustasy at 3·2–3·1 Ma. Incision of the Parker strath is interpreted as a response to eustasy at 2·5–2·4 Ma. A third incision event at c. 1·5 Ma corresponds with glacial reorganization of the Ohio River basin. Widespread aggradation of cave passages at c. 0·85 Ma is interpreted as the beginning of intense glacial–interglacial cycling associated with global climate change. Copyright © 2006 John Wiley & Sons, Ltd.
Mechanisms of deep benzene oxidation on the Pt(111) surface using temperature-programmed reaction methods

Abstract The catalytic oxidation of benzene on the Pt(1 1 1) surface has been characterized using temperature-programmed reaction spectroscopy (TPRS) over a wide range of benzene and oxygen coverages. Coadsorbed atomic oxygen and benzene are the primary reactants on the surface during the initial oxidation step. Benzene is oxidized over the 300–500 K range to produce carbon dioxide and water. Carbon–hydrogen and carbon–carbon bond activation are clearly rate-limiting steps for these reactions. Preferential oxidation causes depletion of bridge-bonded benzene, suggesting enhanced reactivity in this bonding configuration. When oxygen is in excess on the surface, all of the surface carbon and hydrogen is oxidized. When benzene is in excess on the surface, hydrogen produced by dehydrogenation is desorbed after all of the surface oxygen has been consumed. Repulsive interactions between benzene and molecular oxygen dominate at low temperatures. Preadsorption of oxygen inhibits adsorption of less reactive benzene in threefold hollow sites. The desorption temperature of this non-reactive chemisorbed benzene decreases and overlaps with the multilayer desorption peak with increasing oxygen exposure. The results presented here provide a clear picture of rate-limiting steps during deep oxidation of benzene on the Pt(1 1 1) surface.
Reproducibility of X-Ray Survival Curves for Yeast Cells.

SummaryAccurate and reproducible X-ray-survival curves were obtained for both haploid and diploid yeast under carefully controlled conditions. The haploid curve is exponential down to survivals of 10−4 or lower for old cultures; the diploid curve is sigmoid and a good fit can be obtained by use of the proper multi-target model. The slope of the haploid survival curve (the radiosensitivity) depends on the culture age, young cultures being more sensitive. The haploid curves exhibit “tails” at low survival levels; the position of the tail is also dependent on the culture age, young cultures showing the tail at higher survival levels. The goodness of fit of the experimental points of the haploid yeast survival curves to an exponential curve is evidence that the rate-limiting inactivation step is first order as postulated in the diffusion model of Zirkle and Tobias.
Resilience of Arctic mycorrhizal fungal communities after wildfire facilitated by resprouting shrubs

Abstract: Climate-induced changes in the tundra fire regime are expected to alter shrub abundance and distribution across the Arctic. However, little is known about how fire may indirectly impact shrub performance by altering mycorrhizal symbionts. We used molecular tools, including ARISA and fungal ITS sequencing, to characterize the mycorrhizal communities on resprouting Betula nana shrubs across a fire-severity gradient after the largest tundra fire recorded in the Alaskan Arctic (July—October 2007). Fire effects on the components of fungal composition were dependant on the scale of taxonomic resolution. Variation in fungal community composition was correlated with fire severity. Fungal richness and relative abundance of dominant taxa declined with increased fire severity. Yet, in contrast to temperate and boreal regions with frequent wildfires, mycorrhizal fungi on resprouting shrubs in tundra were not strongly differentiated into fire-specialists and fire-sensitive fungi. Instead, dominant fungi, inc...
Sequences of Diophantine approximations

Abstract We sharpen a technique of Gelfond to show that, in a sense, the only possible gap-free sequences of “good” Diophantine approximations to a fixed α ∈ C are trivial ones. For example, suppose that a > 1 and that (δn)n=1∞ and (σn)n=1∞ are two positive, strictly increasing unbounded sequences satisfying δn+1 ≤ aδn and σn+1 ≤ aσn. If there is a sequence of nonzero polynomials Pn ∈ Z[x] with deg Pn ≤ δn, deg Pn + log height Pn ≤ σn, and ∣Pn(α)∣ ≤ e−(2a+1)δnσn, then each Pn(α) = 0.
Color change: A non-invasive measure of melatonin action

Abstract Research on melatonin's role in photoperiodic phenomena and the molecular mechanism of melatonin action would profit from understanding melatonin's action upon pigment cells and from incorporation of pigment cell and pelage parameters into experimental paradigms. Pigment cell activity is modified by melatonin through both direct and indirect mechanisms. Melatonin's influence upon physiological color change, i.e. the transfer of melanosomes in and out of melanophore processes, is the result of a direct effect upon the pigment cell. Melatonin's influence upon morphological color change, i.e. the transfer of pigment granules to surrounding cornified cells such as hair, is primarily mediated by melatonin-induced decreases in pituitary prolactin output, an indirect mechanism of action. Study of morphological color change is valuable to those interested in photoperiodic phenomena, whereas study of physiological color change is valuable to those interested in the molecular mechanism of melatonin action. This review details current concepts relevant to melatonin's role in both morphological and physiological color change. We also introduce the reader to pigment cell model systems available for study of melatonin action at the cellular level.
Investigating the physiology of brain activation with MRI

Functional magnetic resonance imaging (fMRI) has become a powerful tool for investigating the working human brain based on the blood oxygenation level dependent (BOLD) effect on the MR signal. However, despite the widespread use of fMRI techniques for mapping brain activation, the basic physiological mechanisms underlying the observed signal changes are still poorly understood. Arterial spin labeling (ASL) techniques, which measure cerebral blood flow (CBF) and the BOLD effect simultaneously, provide a useful tool for investigating these physiological questions. In this paper, recent results of studies manipulating the baseline CBF both pharmacologically and physiologically will be discussed. These data are consistent with a feed-forward mechanism of neurovascular coupling, and suggest that the CBF change itself may be a more robust reflection of neural activity changes than the BOLD effect. Consistent with these data, a new thermodynamic hypothesis is proposed for the physiological function of CBF regulation: maintenance of the [O 2 ]/[CO 2 ] concentration ratio at the mitochondria in order to preserve the free energy available from oxidative metabolism. A kinetic model based on this hypothesis provides a reasonable quantitative description of the CBF changes associated with neural activity and altered blood gases (CO 2 and O 2 ).
Leveraging data intensive computing to support Automated Event Services

Our AES is an ideal example of a new generation of scientific analysis tools that are empowered by the rapid growth of facilities tailored for data-intensive computing. AES will greatly reduce the effort on the part of investigators to systematically search for interesting correlations and test hypotheses while also freeing researchers from the burden of managing the exploding volume of data. By supporting the ability to exchange event specifications and query results, AES greatly aids collaboration among investigators. We anticipate that AES will ultimately lead to entirely novel lines of investigation.
The Forkhead Box M1 Transcription Factor Contributes to the Development and Growth of Mouse Colorectal Cancer

Background & Aims: In this study, we used Forkhead Box m1b (Foxm1b) transgenic mice and conditional Foxm1 knock-out mice to examine the role of Foxm1 in colon cancer development and proliferation. Methods: To induce mouse colorectal cancer, we used a single intraperitoneal injection of azoxymethane (AOM) followed by three 1-week cycles of 2.5% dextran sodium sulfate (DSS) water, each cycle separated by 2 weeks. For these colon tumor studies, we used either Rosa26-Foxm1b transgenic mice that ubiquitously expressed the human Foxm1b complementary DNA or mice in which the Foxm1 fl/fl targeted allele was deleted in colonic epithelial cells using the gut-specific Villin-Cre recombinase transgene (Villin-Cre). Colorectal tumor number and bromodeoxyuridine labeling were determined in Rosa26-Foxm1b mice, Villin-Cre Foxm1-/-, mice and wild-type mice after 12 weeks of AOM/DDS exposure. We also used Foxm1 small interfering RNA–depleted human DLD1 and mouse CT26 colon cancer cell lines to examine DNA replication and anchorage-independent growth. Results: After 12 weeks of treatment with AOM/DSS, Rosa26 Foxm1b transgenic mice showed an increase in the number and size of colorectal tumors compared with wild-type mice. Likewise, a significant reduction in the development and growth of colorectal tumors was found in Villin-Cre Foxm1-/- mice compared with Foxm1 fl/fl mice after AOM/DSS treatment, which was associated with decreased expression of cyclin A2, cyclin B1, survivin, and T-cell factor 4 genes. Moreover, Foxm1-depleted colon cancer cell lines showed reduced DNA replication and anchorage-independent growth. Conclusions: These studies suggest that Foxm1 is critical for the proliferation and growth of colorectal cancer.
Effects of programming experience in debugging semantic errors

Abstract This paper presents the results of a controlled experiment comparing debugging abilities of novice, intermediate, and skilled student programmers. Debugging-performance differences were studied using two single-page Pascal programs: a binary search program and a median calculation program. Two types of semantic errors, array bounds and undefined variable, and two types of error messages, with and without line number, were varied within the two programs. Subjects were asked to find and correct a single error in each program. Results demonstrate skill-level differences, show the importance of error and message interaction, and support previous research claiming that programmers can almost always correct an error once it is located.
Frozen-flux modelling for epochs 1915 and 1980

The frozen-flux hypothesis for the Earth's liquid core assumes that convective terms dominate diffusive terms in the induction equation governing the behaviour of the magnetic field at the surface of the core. While highly plausible on the basis of estimates of physical parameters, the hypothesis has been questioned. To study this hypothesis, we improve the method which tests the consistency of magnetic observations with the hypothesis by constructing simple, flux-conserving core-field models fitting the data at pairs of epochs. We introduce a new approach that fixes the patch configurations at each of the two epochs before inversion, so that each configuration is consistent with its respective data set but possesses the same patch topology. We expand upon the inversion algorithm, using quadratic programming to maintain the proper flux sign within patches; the modelling calculations are also extended to include data types that depend non-linearly on the model. Every test of a hypothesis depends on the characterization of the observational uncertainties; we undertake a thorough review of this question. For main-field models, the primary source of uncertainty comes from the crustal field. We base our analysis on statistical models of the crustal magnetization, adjusted to bring it into better conformity with our data set. The noise model permits us to take into account the correlations between the measurements and requires that a different weighting be given to horizontal and vertical components. It also indicates that the observations should be fit more closely than has been the practice heretofore. We apply the revised method to Magsat data from 1980 and survey and observatory data from 1915.5, two data sets believed to be particularly difficult to reconcile with the frozen-flux hypothesis. We compute a pair of simple, flux-conserving models that fit the averaged data from each epoch. We therefore conclude that present knowledge of the geomagnetic fields of 1980 and 1915.5 is consistent with the frozen-flux hypothesis.
Status of the National Ignition Facility: An optics perspective

The NIF is now operating the first four of its 192 independent laser beamlines. The design of the laser system is discussed from an optics perspective and the status of the optics manufacturing effort reviewed.
Long-term results of radiosurgery for arteriovenous malformation: Neurodiagnostic imaging and histological studies of angiographically confirmed nidus obliteration

Abstract Detailed follow-up results for 25 patients treated for cerebral arteriovenous malformation (AVM) with a gamma unit are presented. Complete nidus obliteration was angiographically confirmed in 16 (73%) of 22 cases receiving full-dose irradiation. There were no radiation- or AVM-related mortalities. However, we did experience one case of radiation-related morbidity and one of angiographyrelated mortality, the autopsy findings of which are discussed. Computed tomography scan and magnetic resonance imaging follow-up studies of radiosurgically treated AVMs indicated that increased enhancement of the nidus after contrast or gadolinium administration could persist even after obliteration of the AVM was angiographically confirmed.
Fibrobacter succinogenes S85 ferments ball-milled cellulose as fast as cellobiose until cellulose surface area is limiting.

Fibrobacter succinogenes S85 grew rapidly on cellobiose (0.31 h−1) and the absolute rate of increase in fermentation acids was 0.68 h−1. Cultures that were provided with ball-milled cellulose initially produced fermentation acids and microbial protein as fast as those provided with cellobiose, but the absolute cellulose digestion rate eventually declined. If the inoculum size was increased, the kinetics decayed from first to zero order (with respect to cells) even sooner, but in each case the absolute rate declined after only 20 to 30% of the cellulose had been fermented. Congo red binding indicated that the cellulose surface area of individual cellulose particles was not decreasing, and the transition of ball-milled cellulose digestion corresponded with the appearance of unbound cells in the culture supernatant. When bound cells from partially digested cellulose were removed and the cellulose was re-incubated with a fresh inoculum, the initial absolute fermentation rate was as high as the one observed for undigested cellulose and cellobiose. Based on these results, cellulose digestion by F. succinogenes S85 appears to be constrained by cellulose surface area rather than cellulase activity per se.
Elastic interactions and the metallurgical and acoustic effects of carbon in the Caribbean steel drum

Abstract Requisite amounts of carbon interact with dislocations in deformed drum steel composing the note platform for the Caribbean steel drum (or pan) to produce complex, nonlinear behavior, especially notable in harmonic frequency spectra. Experiments on flat, circular disks prepared from high-quality, low-carbon (0.04 wt.% C) drum steel illustrate harmonic spectrum changes and frequency peak variation (which appear to occur by splitting), which is related to characteristic deformation (or strain). This, in turn, is related to dislocation density. Similar frequency variation characteristics were also observed in actual drum notes. Detailed texture measurements revealed only about 3% variation in the elastic moduli for the undeformed and heavily deformed drum steel. Detailed tempering diagrams illustrate the variations of residual microhardness with aging temperature, time, strain, and carbon content, while stress–strain diagrams show more detailed carbon dislocation dynamic interactions. While strain aging is a prominent feature of drum tempering, high-quality instruments can be developed and tuned even without noticeable strain aging by varying the methodology to manipulate the internal stresses to produce requisite elastic–plastic interactions. This could be achieved by strain-induced ordering of interstitial carbon (Snoek effect) and by dislocation pinning and unpinning by carbon atoms in a dynamic fashion (Portevin–Le Châtelier effect). A carbon threshold occurs below about 0.02 wt.% C and an anomalous hardening occurs in drum steels heat-treated at 800 °C due to martensite nucleating and growing at the original ferrite grain boundaries upon quenching. This microstructure is carbon-dependent, increasing with increasing carbon content above the ∼0.02 wt.% C threshold. Below this carbon threshold, there is no strain aging or high-temperature hardening. Frequency spectra from heat-treated disks show an enhancement of the frequency variations and the generation of more harmonics.
Clarifying the distinction between lexical and gestural commands

A distinction is drawn between conventional lexical commands and gestural commands (e.g. circles, arrows, X'x, etc.). The distinction is discussed in the context of a central metaphor that likens computer use to communication between programmer and user. A number of limitations and benefits unique to gestural interfaces are described. It is suggested that gestural commands tend to be terse, common, unambiguous, iconic, and similar to the spontaneous hand gestures that accompany speech. The potential effects of these five qualities are outlined by summarizing selected research from cognitive and social psychology. Some potential applications are also described.
The long-term efficacy of multivisceral transplantation.

Under tacrolimus-based immunosuppression, long-term rehabilitation has become achievable with intestinal transplantation. 1 Herein, we report our 9-year experience with multivisceral transplantation for patients with diffuse irreversible gastrointestinal diseases.
Dynamics of Myo1c (Myosin-Iβ) Lipid Binding and Dissociation *

Myosin-I is the single-headed member of the myosin superfamily that associates with lipid membranes. Biochemical experiments have shown that myosin-I membrane binding is the result of electrostatic interactions between the basic tail domain and acidic phospholipids. To better understand the dynamics of myosin-I membrane association, we measured the rates of association and dissociation of a recombinant myo1c tail domain (which includes three IQ domains and bound calmodulins) to and from large unilamellar vesicles using fluorescence resonance energy transfer. The apparent second-order rate constant for lipid-tail association in the absence of calcium is fast with nearly every lipid-tail collision resulting in binding. The rate of binding is decreased in the presence of calcium. Time courses of myo1c-tail dissociation are best fit by two exponential rates: a fast component that has a rate that depends on the ratio of acidic phospholipid to myo1c-tail (phosphatidylserine (PS)/tail) and a slow component that predominates at high PS/tail ratios. The dissociation rate of the slow component is slower than the myo1c ATPase rate, suggesting that myo1c is able to stay associated with the lipid membrane during multiple catalytic cycles of the motor. Calcium significantly increases the lifetimes of the membrane-bound state, resulting in dissociation rates ≪ 0.001 s−1.
Assessing Return on Investment of Freeway Safety Service Patrol Programs

Safety service patrol (SSP) programs are widely used to help mitigate the effects of nonrecurring congestion and have become an increasingly vital element of incident management programs. In recent years, some state departments of transportation have initiated return-on-investment evaluations of their SSP programs. The purpose of this project was to use Virginia data to develop methods to evaluate and quantify the benefits of SSP programs; this involved developing a methodology to determine incident durations with and without SSPs for the Northern Virginia region and applying the results to a model to quantify the benefits associated with reductions in motorist delay, fuel consumption, and emissions attributable to SSP operations. To verify the general applicability of the methodology, the evaluation procedure was applied to the Hampton Roads, Virginia, SSP. The results showed that incident duration reductions attributable to SSP operations in these two areas resulted in benefit-cost ratios of 5.4:1 and 4...
Aryl vinyl sulfonates and sulfones as active site-directed and mechanism-based probes for protein tyrosine phosphatases.

Protein tyrosine phosphatases (PTPs) play key roles in the regulation of normal and pathological processes ranging from cell proliferation, differentiation, metabolism, and survival to many human diseases including cancer and diabetes. Functional studies of PTP can be greatly facilitated by small molecule probes that covalently label the active site of a PTP through an activity-dependent chemical reaction. In this article, we characterize phenyl vinyl sulfonate (PVSN) and phenyl vinyl sulfone (PVS) as a new class of mechanism-based PTP probes. PVSN and PVS inactivate a broad range of PTPs in a time- and concentration-dependent fashion. The PVSN- and PVS-mediated PTP inactivation is active site-directed and irreversible, resulting from a Michael addition of the active-site Cys Sγ onto the terminal carbon of the vinyl group. Structural and mechanistic analyses reveal the molecular basis for the preference of PVSN/PVS toward the PTPs, which lies in the ability of PVSN and PVS to engage the conserved structur...
Search for finite-mass neutrinos in the decay π+→μ+vμ

Abstract If neutrinos possess non-zero mass, pion decay might have small decay branches to neutrino states with large masses. We have searched for such branches in the decay of pions produced at the Indiana University Cyclotron. The energy spectrum of decay muons shows no evidence for such neutrino branches and if these decays do exist, their branching ratios must be less than 10−2 to 10−3 for neutrino masses in the ranFge 7–33 MeV.
Mineral particles from Asia found in volcanic loess on the island of Hawaii

Abstract X-ray diffraction studies of bulk samples, energy-dispersive analyses of single mineral grains, and X-ray mapping of particles in grain mounts show that quartz grains are present in late Quaternary tephric loess deposits of the Pahala Formation found at Pu'u o Mahana near Ka Lae (South Point) on the island of Hawaii. These particles are as large as 40–60 μm, and make up as much as 1–3% of the deposit. Quartz is virtually unknown in the basalts of the Hawaiian Islands, so these particles were evidently transported more than 10,000 km from Asia by late Quaternary wind storms.
Magnetic circular dichroism spectroscopic characterization of the NOS-like protein from Geobacillus stearothermophilus (gsNOS).

Abstract Nitric oxide synthase (NOS) catalyzes the NADPH- and O 2 -dependent oxidation of l -arginine ( l -Arg) to nitric oxide (NO) and citrulline via an N G -hydroxy- l -arginine (NHA) intermediate. Mammalian NOSs have been studied quite extensively; other eukaryotes and some prokaryotes appear to express NOS-like proteins comparable to the oxygenase domain of mammalian NOSs. In this study, a recombinant NOS-like protein from the thermostable bacterium Geobacillus stearothermophilus (gsNOS) has been characterized using magnetic circular dichroism (MCD) and UV–Vis absorption spectroscopic techniques. Spectral comparisons of ligand complexes (with O 2 , NO and CO) of substrate-bound ( l -Arg or NHA) gsNOS, including the key oxyferrous complex studied at −50 °C in cryogenic mixed solvents, with analogous mammalian NOS complexes indicate overall spectroscopic similarities between gsNOS and mammalian NOSs. However, more detailed spectral comparisons reflect subtle structural differences between gsNOS and mammalian NOSs. This may be due to an incomplete tetrahydrobiopterin (BH 4 )-binding site and low BH 4 -binding affinity, which may become even lower in the presence of cryosolvent in gsNOS. Although BH 4 -binding may be altered, gsNOS appears to require the pterin for NO production since formation of the stable ferric-NO product complex was only observed when excess BH 4 (>150 μM) over gsNOS was present upon single turnover reaction in which O 2 was bubbled into dithionite-reduced NHA-bound protein solution at −35 °C or −50 °C.
Toward an Interdisciplinary Dialogue on Youth, Sexualization, and Health

The commentaries in this issue of the Journal of Sex Research by Vanwesenbeeck and Else-Quest and Hyde on “Bad Girls Rule” are connected to two larger conversations concerning (a) the intersections of sexuality, objectification, culture, health, and power; and (b) academics as public scholars. Vanwesenbeeck makes the case for considering both the risks and the rights associated with sexualization. Else-Quest and Hyde argue for the need to use a developmental lens when discussing girlhood and sexuality. This response recognizes the need for a developmental approach; elaborates on previous critiques about over-reliance on epidemiological terms in the American Psychological Association task force report on the sexualization of girls; and rearticulates the value of placing feminist, cross-disciplinary, and cross-national scholarship at the center, rather than the margins, of this dialogue. Were such a dialogue to occur, evidence of cultural and personal variations of childhood and youth should be considered a...
The Role of Endothelial Progenitor Cells in Postnatal Vasculogenesis: Implications for Therapeutic Neovascularization and Wound Healing

Significance: Postnatal vasculogenesis mediated via endothelial progenitor cells (EPCs) contributes to re-endothelialization and augments neovascularization after ischemia and tissue injury, providing a novel therapeutic application. However, controversy exists with respect to the origin, identification, and contributions of the EPCs to neovascularization, necessitating further study. Recent Advances: Bone marrow (BM) or circulating cells expressing cd133/vascular endothelial growth factor receptor 2 include those with endothelial progenitor capacity. Increasing evidence suggests that there are additional BM-derived (myeloid; mesenchymal cells) and non-BM-derived (peripheral and cord-blood; tissue-resident) cell populations which also give rise to endothelial cells (ECs) and contribute to re-endothelialization and growth factor release after ischemia and tissue injury. Currently, EPCs are being used as diagnostic markers for the assessment of cardiovascular and tumor risk/progression. Techniques aimed at ...
Estimation in the Power Law.

Most psychophysicists neglect to consider how error should be characterized in applications of the power law. Failures of the power law to agree with certain theoretical predictions may be due to bias of parameter estimates. A power law with lognormal product structure is proposed and approximately unbiased parameter estimates are given for several common estimation situations.
Estimating a bivariate survial function and its marginals under positive quadrant dependence

This paper attempts to introduce an estimate of a bivariate survival function F¯ as well as its marginals based on a random sample (X1,Y1),....(Xn,Yn) from F¯ when F¯ is known to belong to a particular class of distributions called positive quadrant dependent (PQD) class.The constriants which define PQD class make finding a nonparametric maximum likelihood estimator among PQD class extremely difficult.In this paper we elect a form of minimum distance approach for estimating F¯.To make numeerical computations feasible, we choose not to minimize the distance, sup norm, between the empirical survival function F¯n and the entire PQD class.Rather our estimator minimizes the distance to F¯n among distributions that places positive mass only on the subset of the observed sample values and satisfy the constraint PQD.
SEL1L, the homologue of yeast Hrd3p, is involved in protein dislocation from the mammalian ER

Protein quality control in the endoplasmic reticulum (ER) involves recognition of misfolded proteins and dislocation from the ER lumen into the cytosol, followed by proteasomal degradation. Viruses have co-opted this pathway to destroy proteins that are crucial for host defense. Examination of dislocation of class I major histocompatibility complex (MHC) heavy chains (HCs) catalyzed by the human cytomegalovirus (HCMV) immunoevasin US11 uncovered a conserved complex of the mammalian dislocation machinery. We analyze the contributions of a novel complex member, SEL1L, mammalian homologue of yHrd3p, to the dislocation process. Perturbation of SEL1L function discriminates between the dislocation pathways used by US11 and US2, which is a second HCMV protein that catalyzes dislocation of class I MHC HCs. Furthermore, reduction of the level of SEL1L by small hairpin RNA (shRNA) inhibits the degradation of a misfolded ribophorin fragment (RI332) independently of the presence of viral accessories. These results allow us to place SEL1L in the broader context of glycoprotein degradation, and imply the existence of multiple independent modes of extraction of misfolded substrates from the mammalian ER.