cssi/SciSciGPT-SciSciNet huggingface dataset:
An integral equation method applied to mode III crack problems

Abstract In a series of previous papers [N. J. Altiero et al., Int. J. Fracture38. 24–41 (1988); Comput. Meth. appl. Mech. Engng84, 211–226 (1990); Mech. Res. Commun.18, 233–244 (1991)], an integral equation representation of cracks was developed and coupled to the direct boundary-element method for treatment of cracks in plane finite bodies. The method was developed for in-plane (modes I and II) loadings only. In this paper, the method is formulated and applied to mode III problems involving smooth or kinked cracks in finite regions. The results are compared to exact solutions where available [S. W. Ma, Engng Fracture Mech.30, 435–443 (1988); Int. J. Fracture39, 323–329 (1989)] and the method is shown to be very accurate despite its simplicity.
Cholestasis and growth in neonates with gastroschisis

Abstract Purpose The aim of this study was to determine the incidence of cholestasis and the correlation between cholestasis and weight-for-age z scores in parenteral nutrition–dependent neonates with gastroschisis. Methods A single-center retrospective review of 59 infants born with gastroschisis from January 2000 to June 2007 was conducted. Demographic and clinical data were collected and analyzed. Subjects were divided into cholestatic and noncholestatic groups. Statistical analyses included the Student t test, Wilcoxon rank sum test, Fisher exact test, and a general linear model. Results Fifty-nine neonates with gastroschisis were identified, and 16 (28%) of 58 patients developed cholestasis. Younger gestational age and cholestasis were found to be independently associated with weight-for-age z score in 30 of 58 patients with available long-term follow-up data. Conclusions Parenteral nutrition–dependent neonates with gastroschisis remain at considerable risk for the development of cholestasis. Both gestational age and cholestasis were found to be independent risk factors, predisposing these neonates to poor postnatal growth.
Artery calcification in uremic rats is increased by a low protein diet and prevented by treatment with ibandronate

The present experiments investigate medial artery calcification in adult rats made uremic by feeding a synthetic diet containing 0.75% adenine for 4 weeks. Calcification was assessed by Alizarin red staining of intact aortas, by von Kossa staining of carotid artery sections, and by calcium and phosphate incorporated into the thoracic aorta. The major conclusions are as follows: Lowering the protein content of the diet from 25 to 2.5% dramatically increases the frequency and extent of medial artery calcification in uremic rats without significantly affecting the elevation in serum creatinine, phosphate, or parathyroid hormone. This observation suggests that low dietary protein intake could be a risk factor for medial artery calcification in uremic patients. Medial artery calcification in uremic rats is prevented by a dose of ibandronate that inhibits bone resorption. The observation suggests that bone resorption inhibitors could prevent artery calcification in uremic patients. Medial artery calcification in uremic rats correlates with increased serum bone Gla protein (BGP; osteocalcin), but not with serum matrix Gla protein or fetuin. This finding indicates that it could be of interest to examine the relation between serum BGP and artery calcification in uremic patients. Each of these conclusions lends support for our hypothesis that medial artery calcification is linked to bone resorption. Future investigations of the as yet unknown biochemical basis for this link will be facilitated by the present discovery that a synthetic, 2.5% protein diet containing 0.75% adenine produces consistent and dramatic medial calcification in adult rats within just 4 weeks.
Transient buccal nerve paresis.

Infiltration of a local anesthetic agent (e.g., lidocaine) in the vicinity of the facial nerve can transiently paralyze the temporal branch of the facial nerve and cause ipsilateral brow ptosis. This typically occurs during surgery to remove skin cancers on the temple. The buccal nerve typically is not prone to transient or permanent damage because it lies deep to the buccal fat pad. A case of transient buccal nerve paresis secondary to local anesthetic administration is presented.
Benzodiazepinone Derivatives as CRTH2 Antagonists.

Multiple CRTH2 antagonists are currently evaluated in human clinical trials for asthma and chronic obstructive pulmonary disease (COPD). During our lead optimization for CRTH2 antagonists, an observation of an intramolecular hydrogen bond in ortho-phenylsulfonamido benzophenone derivatives led to the design and synthesis of conformationally constrained benzodiazepinones as potent CRTH2 antagonists. The benzodiazepinones are 2 orders of magnitude more potent than the original flexible bisaryl ethers in our binding assay. Selected benzodiazepinones, such as compound 6, were also potent in the human eosinophil shape change assay. Analysis of the rigid conformations of these benzodiazepinones and ortho-phenylsulfonamido benzophenones provided an explanation for the structure–activity relationship and revealed the possible bound conformations to CRTH2, which may be useful for building a pharmacophore model of CRTH2 antagonists.
17O and 63,65Cu NMR of undoped and hole-doped Cu2O3 two-leg spin-ladder A14Cu24O41 up to K

We carried out the first 17O as well as 63,65Cu NMR in the S"1 Cu 2 O 3 two-leg spin-ladder, and observed the crossover of magnetic excitations from the spin gap to the paramagnetic regime. In hole-doped ladders, the magnetic crossover is accompanied by the transfer of holes from the CuO 2 chain layer to the Cu 2 O 3 ladder layer. ( 1999 Elsevier Science B.V. All rights reserved.
Differential effects of secretagogues on the electrophysiology of the Malpighian tubules of the yellow fever mosquito

1. Segments ofAedes aegypti Malpighian tubules were isolated and perfused with symmetrical solutions, and the transepithelial electrical potential difference (Vt) and resistance (Rt) were determined. 2. Vt avaraged 53±3 (110) mV lumen positive (mean±SE, number of tubules), and was inhibited by dinitrophenol, but not by amiloride, furosemide, or ouabain (all added to the serosal medium). Rt averaged 21±4(15) kohm­cm. 3. Following treatment with the secretagogue dibutyryl cAMP (1 mM), Vt increased to 99±8(9) mV and Rt dropped to, 14±6(6) kohm·cm. Effects of cAMP were reversible and dependent upon serosal [Na]. 4. Treatment with another secretagogue, an extract of mosquito heads (0.1 head/μl), caused Vt to drop to 1±1(8) mV and Rt to fall to 9±3(7) kohm·cm. These effects were also reversible, but they were dependent upon serosal [Cl]. 5. Since previous studies showed that cAMP stimulates secretion of Na in these tubules, it is concluded that cAMP stimulates active Na transport that is responsible for the observed increase in Vt. 6. Head extract apparently stimulates the active secretion of K, but the dependence of the head extract effects on Cl, combined with the low Vt seen during head extract treatment, suggests that the secretion of K, and perhaps also of Na, is directly or indirectly coupled to Cl secretion, yielding neutral transport of electrolytes and consequently low values of Vt
Canonical quantization of the Skyrme model

Abstract The canonical quantization of the Skyrme model is presented. Due to the complexities of the original set-up, first postulated by Rajeev, a new set of fields is found which satisfy a Lie algebra and for this reason, simplifies the study of the system. Using the new fields, the properties of the states under rotations are examined. As a result we re-derive the quantization of the coefficient of the Wess-Zumino action as an a priori consistency condition. We also find under what circumstances states with non-vanishing winding number behave like fermions.
The Adsorption Properties of Bacillus atrophaeus Spores on Single-Wall Carbon Nanotubes

An adsorption equilibrium and a kinetic study of Bacillus atrophaeus on Single-Wall Carbon Nanotubes (SWCNTs) were here performed to provide the basis for developing biosensor devices for detecting threatening micro-organisms in water supply systems. B. atrophaeus spores and carbon nanotubes were subjected to a batch adsorption process to document their equilibria and kinetics. Here, commercial nanotubes were either studied as received or were acid-purified before adsorption experiments. The Bacillus spores appear to show higher affinity towards the purified nanotubes than to the as-received nanomaterial. The effective diffusivity of the spores onto the purified nanotubes was found to be approximately 30 percent higher than onto the as-received nanotubes. It seems that the removal of amorphous carbon from the as-received nanotubes through a purification process yielded an intimate nantoubes-spore interaction as revealed by transmission electron microscopy. Freundlich model successfully correlated the adsorption equilibrium data for the nanotubes-spore interaction. Transmission electron micrographs showed extensive contact between the Bacillus and the purified nanotubes, but the association appeared less intimate between the spores and the as-received nanotubes.
Effects of Prior Knowledge Activation Modes and Text Structure on Nonscience Majors’ Comprehension of Physics

AbstractOur purpose in this study was to investigate a pragmatic, low-cost way to enhance student learning of complex science concepts without totally revamping texts or methods of instruction. Undergraduate nonscience majors (N = 62) with known naive conceptions about projectile motion were randomly assigned to one of six groups formed from three levels of a prior knowledge activation activity and two levels of text. The results of a multivariate analysis of variance showed that activating competent readers’ naive conceptions about a complex science concept is not as effective a means for dispelling inaccurate information as is the practice of activating their naive conceptions and then explicitly directing them to read and attend to ideas that might differ from their own. This result and the no difference found for refutation text are discussed within the context of earlier work and Kintsch’s (1980) observation that incongruity leads to new learning.
Preliminary study on diffraction enhanced radiographic imaging for a canine model of cartilage damage.

Summary Objective To demonstrate the ability of a novel radiographic technique, Diffraction Enhanced Radiographic Imaging (DEI), to render high contrast images of canine knee joints for identification of cartilage lesions in situ . Methods DEI was carried out at the X-15A beamline at Brookhaven National Laboratory on intact canine knee joints with varying levels of cartilage damage. Two independent observers graded the DE images for lesions and these grades were correlated to the gross morphological grade. Results The correlation of gross visual grades with DEI grades for the 18 canine knee joints as determined by observer 1 ( r 2 =0.8856, P =0.001) and observer 2 ( r 2 =0.8818, P =0.001) was high. The overall weighted κ value for inter-observer agreement was 0.93, thus considered high agreement. Conclusion The present study is the first study for the efficacy of DEI for cartilage lesions in an animal joint, from very early signs through erosion down to subchondral bone, representing the spectrum of cartilage changes occurring in human osteoarthritis (OA). Here we show that DEI allows the visualization of cartilage lesions in intact canine knee joints with good accuracy. Hence, DEI may be applicable for following joint degeneration in animal models of OA.
Multi-objective optimization of dead-reckoning error thresholds for virtual environments

Design trade-offs between state consistency and system response time are commonplace in virtual environments. Systems typically rely on predictive consistency algorithms such as dead-reckoning to control consistency and response time. Dead-reckoning error threshold selection determines the consistency/response time trade-off. We extend this trade-off space to explicitly account for the concept of system fairness. We derive a multi-objective optimization problem and apply multi-objective evolutionary algorithms to solve for Pareto optimal error thresholds.
Nitrogen and Phosphorus Availability in Enriched, Pelletized Poultry Litters

The highly concentrated nature of the poultry industry on the Delmarva (Delaware-Maryland-Virginia) peninsula, an area dominated by sandy soils and shallow ground and surface water contamination from N and P in poultry wastes. When poultry litters and fertilizer sales are combined an average excess, beyonf the requirements of agricultural crops, of 48 kg N/ha and 16 kg P/ha is estimated to occur in Delaware annually. Movement of excess poultry wastes to areas of nutrient deficiency is often hindered by their low nutrient content and physical properties. Because manures (and other wastes) are usually wet, bulky materials with low concentrations of the major plant nutrients (N, P, K), large volumes must be handled and transported to provide adequate nutrients for most crops. As handling and transportation costs increase, the distance of transport decreases; hence, manure nutrients are often concentrated in localed areas. Pelletization and enrichment of poultry litters with inorganic fertilizations to give h...
Chapters from the History of Physical Training in Ancient and Medieval Europe

(1907). Chapters from the History of Physical Training in Ancient and Medieval Europe. American Physical Education Review: Vol. 12, No. 4, pp. 289-302.
Contribution of caudal brainstem to d-fenfluramine anorexia

Of the central 5-HT substrates that may mediate the anorexic actions of systemically administered d-fenfluramine (d-FEN), those in the forebrain have received the most attention. As a counterpoint to this forebrain focus, we evaluated the contribution of caudal brainstem substrates to the anorexic action of d-FEN. Two experimental protocols were employed. In one we compared the feeding response (intra-oral intake of 12.5% glucose) of intact and chronic supracollicular decerebrate (CD) rats to systemic administration of d-FEN. In the other, d-FEN was administered via fourth intracerebroventricular (ICV) injection to determine whether a dose-related suppression of intra-oral intake could be obtained. A dose-dependent suppression of intra-oral intake was obtained in the CD rat treated with d-FEN (0–8 mg/kg, delivered IP 20 min before testing). The threshold dose was two to three times higher in CD rats than in their intact controls, but the dynamic range of the dose-response curves of the two groups were overlapping with similar slopes of decline and with comparable maximal intake suppression. Fourth ICV administration of d-FEN in the intact rat yielded a dose-related suppression of intra-oral intake. Intake was also suppressed by fourth ICV d-FEN (30 mg) when rats drank 12.5% glucose solution from a spout. The reduced intra-oral intake following fourth ICV d-FEN treatment was partially attenuated by the systemic administration of the serotonin antagonist metergoline (0.4 mg/kg; IP). The CD results demonstrate the sufficiency of caudal brainstem receptors in mediating intake suppressive responses to systemic d-FEN. The fourth ICV results suggest further that 5-HT receptors in the caudal brainstem play a significant role in normal meal size control in the neurologically intact rat.
Iterative total least-squares image reconstruction algorithm for optical tomography by the conjugate gradient method

We present an iterative total least-squares algorithm for computing images of the interior structure of highly scattering media by using the conjugate gradient method. For imaging the dense scattering media in optical tomography, a perturbation approach has been described previously [ Y. Wang , Proc. SPIE1641, 58 (1992); R. L. Barbour , in Medical Optical Tomography: Functional Imaging and Monitoring (Society of Photo-Optical Instrumentation Engineers, Bellingham, Wash., 1993), pp. 87–120], which solves a perturbation equation of the form WΔx=ΔI. In order to solve this equation, least-squares or regularized least-squares solvers have been used in the past to determine best fits to the measurement data ΔI while assuming that the operator matrix W is accurate. In practice, errors also occur in the operator matrix. Here we propose an iterative total least-squares (ITLS) method that minimizes the errors in both weights and detector readings. Theoretically, the total least-squares (TLS) solution is given by the singular vector of the matrix [W|ΔI] associated with the smallest singular value. The proposed ITLS method obtains this solution by using a conjugate gradient method that is particularly suitable for very large matrices. Simulation results have shown that the TLS method can yield a significantly more accurate result than the least-squares method.
Triangular Dirichlet Kernels and Growth of L p Lebesgue Constants

Let P be a polygon in ℤ2 and consider the mapping of an \(L^{1}(\mathbb{T}^{2})\) function into the partial sum of its Fourier series determined by the dilate of P by the integer N. If the image space is endowed with the Lp norm, 1<p<∞, then the operator norm will be given by the Lp norm of ∑(m,n)∈NPe2πi(mx+ny). The size of this operator norm is shown to be O(N2(1−1/p)) when the polygon is a triangle. The estimate is independent of the shape of the triangle. For a k sided polygon the corresponding estimate is O(kN2(1−1/p)).
Numerical simulation of pattern formation in grain flows

Abstract We present numerical computations for the flow of granular materials in hoppers. The algorithm is based on a cellular automaton approach and takes into account various microscopic effects, including “orientational effects”. The formation and the dynamics of density waves, recently discovered in physical experiments, is observed and analyzed computationally.
A search for hot pulsators similar to PG 1159-035 and the central star of K 1-16

The four known pulsators lie at 80, 000 K < Teff < 160, 000 K and 6 < log g < 8, or about 1.5 < log L/L < 3, in the HR diagram. Our non-pulsating DO white dwarfs may be outside the temperature range of the instability strip, being slightly cooler than the GW Vir pulsators (or slightly hotter in the case of H 1504+65).The non-pulsating planetary nuclei have high temperatures and show helium and carbon features in their spectra, but are more luminous than the pulsators, since they have decidedly lower surface gravities.
Modeling the Relationship between Restaurant Tipping and Consumer Behavior

The theory of consumer choice was applied to model the relationship between restaurant tipping and consumer behavior. Using this model, we showed how consumer behavior responds to restaurant tipping and how tipping affects consumer-utility among different types of consumers and economic efficiency. The theoretical analysis reveals that tipping discourages customers’ demand for restaurant meals, which in turn creates bigger excess burden in the market.
STABILIZED1, a Stress-Upregulated Nuclear Protein, Is Required for Pre-mRNA Splicing, mRNA Turnover, and Stress Tolerance in Arabidopsis

In plants, many gene transcripts are very unstable, which is important for the tight control of their temporal and spatial expression patterns. To identify cellular factors controlling the stability of unstable mRNAs in plants, we used luciferase imaging in Arabidopsis thaliana to isolate a recessive mutant, stabilized1-1 (sta1-1), with enhanced stability of the normally unstable luciferase transcript. The sta1-1 mutation also causes the stabilization of some endogenous gene transcripts and has a range of developmental and stress response phenotypes. STA1 encodes a nuclear protein similar to the human U5 small ribonucleoprotein–associated 102-kD protein and to the yeast pre-mRNA splicing factors Prp1p and Prp6p. STA1 expression is upregulated by cold stress, and the sta1-1 mutant is defective in the splicing of the cold-induced COR15A gene. Our results show that STA1 is a pre-mRNA splicing factor required not only for splicing but also for the turnover of unstable transcripts and that it has an important role in plant responses to abiotic stresses.
Brief paper: Speed regulation in steering-based source seeking

The simplest strategy for extremum seeking-based source localization, for sources with unknown spatial distributions and nonholonomic unicycle vehicles without position measurement, employs a constant positive forward speed. Steering of the vehicle in the plane is performed using only the variation of the angular velocity. While keeping the forward speed constant is a reasonable strategy motivated by implementation with aerial vehicles, it leads to complexities in the asymptotic behavior of the vehicle, since the vehicle cannot settle-at best it can converge to a small-size attractor around the source. In this paper we regulate the forward velocity, with the intent of bringing the vehicle to a stop, or as close to a stop as possible. The vehicle speed is controlled using simple derivative-like feedback of the sensor measurement (the derivative is approximated with a washout filter) to which a speed bias parameter V"c is added. The angular velocity is tuned using standard extremum seeking. We prove two results. For V"c in a certain range around zero, we show that the vehicle converges to a ring around the source and on average the limit of the vehicle's heading is either directly away or towards the source. For other values of V"c>0, the vehicle converges to a ring around the source and it revolves around the source. Interestingly, the average heading of this revolution around the source is more outward than inward-this is possible because the vehicle's speed is not constant, it is lower during the outward steering intervals and higher during the inward steering intervals. The theoretical results are illustrated with simulations.
Egg consumption and endothelial function: a randomized controlled crossover trial.

Abstract Background: Because of egg cholesterol content, reduction in egg consumption is generally recommended to reduce risk of cardiovascular disease. Recently, however, evidence has been accumulating to suggest that dietary cholesterol is less relevant to cardiovascular risk than dietary saturated fat. This randomized controlled crossover trial was conducted to determine the effects of egg ingestion on endothelial function, a reliable index of cardiovascular risk. Methods: Forty-nine healthy adults (mean age 56 years, 40% females) underwent a baseline brachial artery reactivity study (BARS), and were assigned to two eggs or oats daily for 6 weeks in random sequence with a 4-week washout. A BARS was done at the end of each treatment phase, measuring flow-mediated vasodilation (FMD) in the brachial artery using a high-frequency ultrasound. Results: FMD was stable in both egg and oat groups, and between-treatment differences were not significant (egg −0.96%, oatmeal −0.79%; p value >0.05). Six weeks of egg ingestion had no effect on total cholesterol (baseline: 203.8 mg/dl; post-treatment: 205.3) or LDL (baseline: 124.8 mg/dl; post-treatment: 129.1). In contrast, 6 weeks of oats lowered total cholesterol (to 194 mg/dl; p =0.0017) and LDL (to 116.6 mg/dl; p =0.012). There were no differences in body mass index (BMI), triglyceride, HDL or SBP levels between egg and oat treatment assignments. Conclusion: Short-term egg consumption does not adversely affect endothelial function in healthy adults, supporting the view that dietary cholesterol may be less detrimental to cardiovascular health than previously thought.
A Reconfigurable Flight Management System for Small-Scale Unmanned Air Systems

Unmanned air systems are becoming increasingly pervasive in academia as well as industry. Aerospace research and education have to-date focused on the fundamental aerodynamics, structures, and control technologies required for these systems, typically relying on commercial avionics packages to provide the hardware and baseline software needed for unmanned vehicle flight testing. This paper describes an ongoing effort at the University of Michigan to design, implement, and adapt to multiple platforms an open-source, reconfigurable flight management system. Emphasis has been placed on modularity and extensibility, resulting in a system that equally addresses Aerospace education and research challenges. This paper overviews the avionics and software design, implementation, and testing processes completed to-date. Use of the University of Michigan Flight Management System (UM-FMS) to support education in software engineering, embedded instrumentation, and multi-layer control is discussed, along with adaptation to specific flight vehicles.
p53-Independent dephosphorylation and cleavage of retinoblastoma protein during tamoxifen-induced apoptosis in human breast carcinoma cells

We have investigated several molecular events that occur during the process of tamoxifen-induced apoptosis in human breast carcinoma cells. We show that the treatment of either MCF-7 (containing wild-type p53) or MDA-MB-231 cells (containing mutant p53) with tamoxifen resulted in apoptotic nuclear changes and an increase in the pre-G1 apoptotic population. This was accompanied by activation of the caspase enzymes, as evidenced by specific cleavage of poly(ADP-ribose) polymerase and retinoblastoma (RB) protein. The RB protein was cleaved at both an interior and carboxyl terminus cleavage site. In addition, dephosphorylation of RB was found at an early stage of tamoxifen-induced apoptosis in both cell lines. However, neither induction of p53 in MCF-7 cells nor induction of p21 in either cell line was detected, suggesting that tamoxifen-induced RB dephosphorylation and apoptosis are independent of the p53/p21 pathway. We also observed an increase in levels of the pro-apoptotic Bax protein, the inhibitory cytokine TGF-β1 and the transcription factor c-Myc in tamoxifen-treated MDA-MB-231 cells, suggesting the possible involvement of these proteins during apoptosis in this system.
Fast Deterministic Sampling for Mean and Covariance Estimation in Stochastic Load Flow

This paper proposes a new method for stochastic load flow (SLF) by using deterministic sampling based on sigma-point selection. In stead of conducting time-consuming Monte Carlo simulation, the proposed method can efficiently estimate the mean and covariance of state variables and branch power flow by conducting only 2k+ chosen deterministic power flow for a power system with k normally distributed uncertain parameters. The benefits of the proposed method are: 1) it has accuracy at least to the second order of truncated Taylor series; 2) it needs no derivatives; 3) it is not limited to the size of uncertain parameters. The effectiveness of the proposed method is demonstrated in an example of IEEE 14-bus power system.
Dual energy radiography using active detector technology

A new technology has been implemented using an "active-detector" comprised of two computed radiography (CR) imaging plates in a sandwich geometry for dual-energy radiography. This detector allows excellent energy separation, short exposure time, and high signal to noise ratio (SNR) for clinically robust "bone-only" and "soft-tissue only" images with minimum patient motion. Energy separation is achieved by two separate exposures at widely different kVp's: the high energy (120 kVp+1.5 mm Cu filter) exposure is initiated first, followed by a short burst of intense light to erase the latent image on the front plate, and then a 50 kVp (low energy) exposure. A personal computer interfaced to the x-ray generator, filter wheel, and active detector system orchestrates the acquisition sequence within a time period of 150 msec. The front and back plates are processed using a CR readout algorithm with fixed speed and wide dynamic range. "Bone-only" and "soft-tissue only" images are calculated by geometric alignment of the two images and application of dual energy decomposition algorithms on a pixel by pixel basis. Resultant images of a calibration phantom demonstrate an increase of SNR/sup 2//dose by /spl sim/73 times when compared to a single exposure "passive-detector" comprised of CR imaging plates, and an /spl sim/8 fold increase compared to a screen-film dual-energy cassette comprised of different phosphor compounds. In conclusion, dual energy imaging with "active detector" technology is clinically feasible and can provide substantial improvements over conventional methods for dual-energy radiography.
Proactive recovery for BTI in high-k SRAM cells

Recent studies of BTI behavior in SRAM cells showed that for high-K metal gate stack technology, PBTI induced V th shift in NMOS is as significant as NBTI induced V th shift in PMOS. Previous techniques of mitigating NBTI in SRAM focus mainly on PMOS and thus lack the ability to mitigate PBTI of NMOS transistors. In this paper, we propose a novel design to recover 4 internal gates within a SRAM cell simultaneously to mitigate both NBTI and PBTI effects. In the evaluated L2 cache, our technique effectively slows down the cell failure probability increase, and achieves 4.64/2.86× (best/worst case) lifetime improvement over normal design.
Exploiting Unix File-System Races via Algorithmic Complexity Attacks

We defeat two proposed Unix file-system race condition defense mechanisms. First, we attack the probabilistic defense mechanism of Tsafrir, et al., published at USENIX FAST 2008. We then show that the same attack breaks the kernel-based dynamic race detector of Tsyrklevich and Yee, published at USENIX Security 2003. We then argue that all kernel-based dynamic race detectors must have a model of the programs they protect or provide imperfect protection. The techniques we develop for performing these attacks work on multiple Unix operating systems, on uni- and multi-processors, and are useful for exploiting most Unix file-system races. We conclude that programmers should use provably-secure methods for avoiding race conditions when accessing the file-system.
Neighborhood Institutions as Resource Brokers: Childcare Centers, Interorganizational Ties, and Resource Access among the Poor

Current theories of how individuals in poor neighborhoods access information and resources have focused primarily on social ties, with concepts such as social isolation dominating discussion. But these theories ignore that individuals often access resources through interorganizational ties. The author suggests that an important role of neighborhood institutions such as churches and childcare centers is to serve as resource brokers —organizations that have ties to businesses, nonprofits, and government agencies rich in resources and that provide their patrons with access to these resources. This article presents a set of propositions to understand how and why neighborhood institutions broker resources and applies these propositions to a case study of 16 childcare centers in high poverty neighborhoods in New York City. The author argues that resource brokers may be understood as interorganizationally networked, loosely coupled entities whose actors respond to pressures of multiple origins, including professional norms and state mandates. He shows that, through mechanisms that vary in their formality and staff dependence, childcare centers provide access to a remarkable array of resources from external organizations. Findings suggest that resource access among the poor should be understood as an organizationally embedded process, and that true disadvantage may result not merely from living in poor neighborhoods, but from not participating in well-connected neighborhood institutions.
Stock-Based versus Cash Compensation: Does the Correlation between Earnings and Stock Returns Matter?

I empirically examine the role of the correlation between earnings and stock returns in determining the structure of compensation packages for top executives. I develop two competing hypotheses on the relation between the returns-earnings correlation and the structure of executive compensation and empirically test the association between the returnsearnings correlation and use of stock-based pay. The results show that the returns-earnings correlation is positively associated with the use of stock-based compensation, after controlling for other determinants of stock-based compensation such as firm size and firm’s growth opportunities.
A selective impairment in attentional disengagement from erotica in obsessive–compulsive disorder

Abstract Although an attentional bias for threat has been implicated in obsessive–compulsive disorder (OCD), evidence supporting such a bias has been inconsistent. Furthermore, few studies have made distinctions between attentional capture vs. attentional disengagement and the extent to which different emotional content modulates attention in OCD also remains unclear. To address these issues, we examined patients with OCD ( n = 30) and controls ( n = 30) during an emotional attentional blink paradigm in which participants searched for a target embedded within a series of rapidly presented images. Critically, an erotic, fear, disgust, or neutral distracter image appeared 200 ms or 800 ms before the target. Impaired target detection was observed among OCD patients relative to controls following erotic distracters, but only when presented 800 ms, and not 200 ms, prior to the target, indicating difficulty with attentional disengagement. Difficulty disengaging from erotic images was significantly correlated with OCD symptoms in the full sample but not with symptoms of trait anxiety. These data delineate a specific information processing abnormality in OCD.
Municipal Choices during a Recession: Bounded Rationality and Innovation

This study reports the findings of a comparative case study analysis of sixteen U.S. municipalities to provide an in-depth examination of the choices municipal leaders are making to address revenue...
New algorithms for pattern recognition of atrial fibrillation and sinus rhythm

Various zero-crossing techniques are used to distinguish between sinus rhythm and atrial fibrillation of different patients. The methods are threshold crossings, sine-wave crossings, threshold crossings of the derivative of the signal, and fast Fourier transform (FFT) analysis. The comparison shows that the sine-wave crossing method is best, because there is no need to normalize or to differentiate the signal (differentiation as a means to remove the DC component is a noisy process). Also, the algorithm is in real time (unlike the FFT procedure) and simple to implement. >
Pilot Elicitation of Expert Judgments on Model Parameters and Research Needs in Forest Radioecology

The high degree of uncertainty in modeling structure and input parameters used to describe radionuclide fate and transport in forest ecosystems has posed difficulties in accurately modeling radionuclide transport. Many dynamic parameters are required for modeling (such as radionuclide residence half-times in forest compartments) and these parameters are typically difficult to measure (e.g., half-lives vary over a wide range: from days to thousands of years). The NATO workshop brought together more than 70 experts in forest radioecology and ecosystem modeling encompassing a wide range of disciplines and backgrounds. It provided a unique opportunity to quantify the state of knowledge on processes and parameters used in forest ecosystem modeling.
What's Going On with the Oakland Museum's "California and the Vietnam Era" Exhibit?

The Oakland Museum's exhibit, What's Going On: California and the Vietnam Era (August 28, 2009 - February 27, 2005), revealed how the discourse of racism manifests itself in the processes and structures of exhibitions. The museum perpetuates a revisionist project characterized by erasure, a retreat from violence, an inversion of victimology, and an over-emphasis on multiculturalist celebrations without critical power analysis. These discursive strategies rationalize the project of American expansionism. This paper examines the process of organizing the exhibit as well as the exhibit itself.
Endothelium-derived hyperpolarizing factor in coronary microcirculation: responses to arachidonic acid.

In coronary resistance vessels, endothelium-derived hyperpolarizing factor (EDHF) plays an important role in endothelium-dependent vasodilation. EDHF has been proposed to be formed through cytochro...
Nonlinear analysis of high angle of attack motions

It is important to understand and predict aircraft departure characteristics throughout the flight envelope. A review of current departure prediction techniques is presented which are based on linearized equations of motion. Included in this review is a unified approach for treating bare airframe and aircraft with augmented stability systems active. The inadequacy of these methods is shown, and the need for nonlinear techniques is presented. Several simple ideas are given which extend the analyses to include nonlinear analysis in departure prediction. However, these methods still lack the requirements for determining the departure characteristics of a truly dynamic system. The application of Liapunov methods to this problem is proposed and a simple example applied to a fighter-type aircraft is given. Another example is presented to which the solution is not known in order to indicate the extent that nonlinearities enter into the departure prediction problem. (Author)
A New Transform Related to Distance From a Boolean Function

We introduce a new transform on Boolean functions generalizing the Walsh–Hadamard transform. For Boolean functions $q$ and $f$ , the $q$ -transform of $f$ measures the proximity of $f$ to the set of functions obtained from $q$ by change of basis. This has implications for security against certain algebraic attacks. In this paper, we derive the expected value and second moment (Parseval’s equation) of the $q$ -transform, leading to a notion of $q$ -bentness. We also develop a Poisson summation formula, which leads to a proof that the $q$ -transform is invertible.
Energetic Material/Polymer Interaction Studied by Atomic Force Microscopy

The interactions of energetic materials and polymers have important implications in safety, long-term storage, and performance of explosives and explosive mixtures. Atomic force microscopy was used to investigate adhesion forces at the molecular scale of nine energetic materials, organic explosives and energetic salts, on eleven common polymers (polyethylene, polyvinylalcohol, poly(vinyl chloride), polycarbonate, polystyrene, poly(methyl methacrylate), styrene-butadiene rubber, poly(4-vinyl phenol), poly(2,6-dimethylphenylene oxide), poly(2,6-diphenyl-p-phenylene oxide) (Tenax®), and polytetrafluoroethylene (Teflon®)). Teflon was the least adhesive polymer to all energetic materials, while no distinct trend could be elucidated among the other polymers or energetic materials.
Flow-Driven Cell Migration under External Electric Fields

Electric fields influence many aspects of cell physiology, including various forms of cell migration. Many cells are sensitive to electric fields, and they can migrate toward a cathode or an anode, depending on the cell type. In this Letter, we examine an actomyosin-independent mode of cell migration under electrical fields. Our theory considers a one-dimensional cell with water and ionic fluxes at the cell boundary. Water fluxes through the membrane are governed by the osmotic pressure difference across the cell membrane. Fluxes of cations and anions across the cell membrane are determined by the properties of the ion channels as well as the external electric field. Results show that without actin polymerization and myosin contraction, electric fields can also drive cell migration, even when the cell is not polarized. The direction of migration with respect to the electric field direction is influenced by the properties of ion channels, and are cell-type dependent.
Synthesis and Secretion of Protein and Pepsinogen by Rabbit Gastric Mucosa in Organ Culture

When maintained in organ culture, rabbit gastric mucosal biopsies incorporated [14C]leucine into tissue protein and secreted labeled protein into culture medium steadily for 24 hr. Incorporation of radioactivity was abolished by cycloheximide. When examined by sodium dodecyl sulfate gel electrophoresis, dextran gel filtration, and ion exchange chromatography, 65 to 90% of macromolecular radioactivity secreted into culture medium migrated coincidentally with enzy- matically assayed pepsinogen. Pepsin activity in cultured biopsies did not decrease during 24 hr of organ culture. Nevertheless, pepsin activity increased linearly in culture medium during this period. Acetylcholine markedly stimulated secretion of labeled protein and pepsinogen by cultured biopsies. In the presence of a subthreshold concentration (10-10 m ) of acetylcholine, pentagastrin, secretin, and the octapeptide of cholecystokinin, all stimulated protein secretion. Over-all incorporation of [14C]leucine into protein by cultured biopsies was stimulated by 10-9 m pentagastrin. These results directly demonstrate: (1) synthesis and secretion of protein and pepsinogen by isolated gastric mucosa, (2) stimulation of gastric secretion of protein by acetylcholine and polypeptide hormones, and (3) stimulation of gastric synthesis of protein by pentagastrin.
Surfactant protein B gene polymorphisms is associated with risk of bronchopulmonary dysplasia in Chinese Han population.

Objective: To investigate the relationship between Surfactant protein B (SP-B) gene polymorphisms and bronchopulmonary dysplasia (BPD) development in preterm infants of China Han ethnic population. Methods: SP-B gene polymorphisms were studied in 134 neonates who were born at 0.05). Conclusion: SP-B -18C/A and 1580C/T polymorphisms are associated with BPD. The 1580C/T polymorphism was protective while the -18C/A polymorphism increased the risk for BPD. SP-B 4564T/C polymorphism is not associated with BPD.
Lack of Influence of Apolipoprotein E Status on Cognition or Brain Structure in Professional Fighters.

Abstract The role of the apolipoprotein e4 allele in moderating cognitive and neuroanatomical degeneration following repeated traumatic brain injury is controversial. Here we sought to establish the presence or absence of such a moderating relationship in a prospective study of active and retired boxers and mixed martial arts fighters. Fighters (n = 193) underwent cognitive evaluations, interviews regarding fight history, MRI of the brain, and genetic testing. We used a series of moderator analyses to test for any relationship of apolipoprotein genotype on structural volumes of brain regions previously established to be smaller in those with the most fight exposure, and on cognitive abilities also established to be sensitive to fight exposure. No moderating relationship was detected in any of the analyses. The results of this study suggest that there is no impact of apolipoprotein genotype on the apparent negative association between exposure to professional fighting and brain structure volume or aspects ...
Monte Carlo Simulations of Nonlinear Ocean Wave Records with Implications for Models of Breaking Waves

A Monte Carlo method for simulating nonlinear ocean wave records as a function of time is described. It is based on a family of probability density functions developed by Karl Pearson and requires additional knowledge of the dimensionless moments of postulated nonlinear wave record, which are the skewness and kurtosis. A frequency spectrum is used to simulate a linear record. It is then transformed to a nonlinear record for the chosen values of the skewness and kurtosis. The result is not a perturbation expansion of the nonlinear equations that describe unbroken waves. It yields simulated wave record that reproduces the chosen values for the skewness and, if needed, the kurtosis of a wave record so that the statistical properties are modeled. A brief history of the development of the linear model, presently in use, is given along with a survey of wave data that show the variability of the nonlinear properties of wave records. The need for a nonlinear model of waves for naval architecture, remote sensing and other design problems is shown. This method cannot provide any information on whether a particular wave will break. Some of the recent results on breaking waves and green water are reviewed. The possibility that this method can be extended based on the concept of a local absorbing patch is described.
Antioxidant Defense Mechanisms

Cells in an aerobic environment generate reactive oxygen and nitrogen species, which have the potential to cause significant damage to cell organelles and individual proteins, which can compromise cell function and ultimately cause cell death. Relevant intracellular sources of reactive oxygen formation include mitochondrial electron transport, the microsomal P-450 system, and various oxidases in peroxisomes and the cytosol. In addition, NADPH oxidases release superoxide and other oxidants into endosomes and to the outside of cells. In order to survive in this environment, cells have developed a sophisticated system of enzymes and small molecules that limit the formation of highly reactive oxygen species and effectively detoxify them. This system includes superoxide dismutases, glutathione peroxidases, catalase, thioredoxins, and peroxiredoxins in various cell organelles. In addition, water-soluble antioxidants such as glutathione and lipid-soluble antioxidants such as tocopherols and carotenoids are critical scavengers of various oxidants. Chelation of unbound transition metals by storage and transport proteins such as ferritin, transferrin, and ceruloplasmin also keeps free metal levels in the cell extremely low and limits oxidant-induced tissue damage. This article summarizes our current knowledge of reactive oxygen formation, the defense systems that control these oxidants, and their pathophysiological relevance in the liver.
Effect of total parenteral nutrition (TPN) on gut associated lymphoid tissue

Effect of total parenteral nutrition (TPN) on gut associated lymphoid tissue (GALT) was examined in rats. Rats were maintained with TPN by the method of Steiger. Control rats were allowed to have the same solution orally. The size of Peyer’s patches in TPN rats was smaller than that in controls. The number of lymphocytes and the ratio of helper/non-helper T cells were decreased in intestinal lymph of TPN rats. The ratio of helper/non-helper T cells was decreased both in the intraepithelial space and in the lamina propria. These data indicate that oral food intake might play a role in the regulation of morphology and function of GALT.
Trusted Browsers for Uncertain Times

JavaScript in one origin can use timing channels in browsers to learn sensitive information about a user’s interaction with other origins, violating the browser’s compartmentalization guarantees. Browser vendors have attempted to close timing channels by trying to rewrite sensitive code to run in constant time and by reducing the resolution of reference clocks. We argue that these ad-hoc efforts are unlikely to succeed. We show techniques that increase the effective resolution of degraded clocks by two orders of magnitude, and we present and evaluate multiple, new implicit clocks: techniques by which JavaScript can time events without consulting an explicit clock at all. We show how “fuzzy time” ideas in the trusted operating systems literature can be adapted to building trusted browsers, degrading all clocks and reducing the bandwidth of all timing channels. We describe the design of a next-generation browser, called Fermata, in which all timing sources are completely mediated. As a proof of feasibility, we present Fuzzyfox, a fork of the Firefox browser that implements many of the Fermata principles within the constraints of today’s browser architecture. We show that Fuzzyfox achieves sufficient compatibility and performance for deployment today by privacysensitive users.