cssi/SciSciGPT-SciSciNet huggingface dataset:
Statistical Verification of Hyperproperties for Cyber-Physical Systems

Many important properties of cyber-physical systems (CPS) are defined upon the relationship between multiple executions simultaneously in continuous time. Examples include probabilistic fairness and sensitivity to modeling errors (i.e., parameters changes) for real-valued signals. These requirements can only be specified by hyperproperties. In this article, we focus on verifying probabilistic hyperproperties for CPS. To cover a wide range of modeling formalisms, we first propose a general model of probabilistic uncertain systems (PUSs) that unify commonly studied CPS models such as continuous-time Markov chains (CTMCs) and probabilistically parametrized Hybrid I/O Automata (P2HIOA). To formally specify hyperproperties, we propose a new temporal logic, hyper probabilistic signal temporal logic (HyperPSTL) that serves as a hyper and probabilistic version of the conventional signal temporal logic (STL). Considering the complexity of real-world systems that can be captured as PUSs, we adopt a statistical model checking (SMC) approach for their verification. We develop a new SMC technique based on the direct computation of significance levels of statistical assertions for HyperPSTL specifications, which requires no a priori knowledge on the indifference margin. Then, we introduce SMC algorithms for HyperPSTL specifications on the joint probabilistic distribution of multiple paths, as well as specifications with nested probabilistic operators quantifying different paths, which cannot be handled by existing SMC algorithms. Finally, we show the effectiveness of our SMC algorithms on CPS benchmarks with varying levels of complexity, including the Toyota Powertrain Control System.
Uncore power scavenger: a runtime for uncore power conservation on HPC systems

The US Department of Energy (DOE) has set a power target of 20-30MW on the first exascale machines. To achieve one exaflop under this power constraint, it is necessary to minimize wasteful consumption of power while striving to improve performance. Toward this end, we investigate uncore frequency scaling (UFS) as a potential knob for reducing the power footprint of HPC jobs. We propose Uncore Power Scavenger (UPSCavenger), a runtime system that dynamically detects phase changes and automatically sets the best uncore frequency for every phase to save power without significant impact on performance. Our experimental evaluations on a cluster show that UPSCavenger achieves up to 10% energy savings with under 1% slowdown. It achieves 14% energy savings with the worst case slowdown of 5.5%. We also show that UPSCavenger achieves up to 20% speedup and proportional energy savings compared to Intel's RAPL with equivalent power usage making it a viable solution even for power-constrained computing.
Hydrolysis and enzymatic degradation of Novichok nerve agents

Abstract Several parameters of the Novichok nerve agents A230, A232 and A234 were determined. Hydrolysis rates were approximately one to three orders of magnitude slower than G-type nerve agents and approximately zero to two orders of magnitude slower than V-type nerve agents. A230 was the most labile Novichok compound followed by A232 then A234. Activation energies (Ea) and frequency factors (A) were determined for all three compounds. The organophosphorus acid anhydrolase (OPAA) enzyme had catalytic efficiencies on the Novichok compounds ranging between 104 and 105 M−1 min−1 with the highest kcat/Km value for A230, then A232 and lastly, A234.
Acid Suppression Medications During Hospitalization as a Risk Factor for Recurrence of Clostridioides difficile Infection: Systematic Review and Meta-analysis

Background Studies have had conflicting results regarding the influence of acid suppression medications (ASM) during hospitalization on the recurrence of Clostridioides difficile infection (CDI). Methods A systematic review and meta-analysis investigating the association between recurrent CDI and ASM use in inpatients was performed. Relevant literature was identified using Medline, Google Scholar, and Web of Science. All human studies were considered regardless of when they were published. Case-control studies, cohort studies, and clinical trials were included if they contained the necessary information to calculate appropriate statistics related to the objective of this study. Review articles, meta-analyses, and commentaries were excluded; however, their references were searched to identify any studies missed. The random-effects model was selected since significant heterogeneity in study design was identified. To evaluate the sensitivity of the analysis various subgroup analyses were performed. Results Our search identified 9 studies involving 5668 patients of whom 1003 (17.7%) developed recurrent CDI. Patients on ASM were 64% more likely to develop recurrent CDI compared to patients not on ASM (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.13 - 2.38; p-value = 0.009; I2=79.54%). Proton pump inhibitor use was associated with an 84% increased risk of recurrent CDI versus no ASM (OR, 1.84; 95% CI, 1.18 - 2.85; p-value=0.007; I2=83.4%). Conclusions ASM use during hospitalization was associated with a 64% increase in recurrent CDI. The association was greater with PPI use. Due to significant heterogeneity in the analyses, additional studies are essential to further elucidate iatrogenic effect of ASM. Unnecessary PPI use should always be discontinued.
Temporary new implant spacers increase post-reimplantation total knee prosthesis survival after periprosthetic joint infection.

Two-stage exchange arthroplasty is considered the gold standard for treatment of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Antibiotic cement spacers can include cement-based spacers (CBS), new components (NEW), and autoclaved components (ACL). The factors that most influence post-reimplantation prosthesis (PRP) survival were determined. A retrospective database review of patients undergoing two-stage exchange arthroplasty from 2008 to 2014 was performed. There were 85 patients, 25 patients and 30 patients in CBS, NEW and ACL groups, respectively. Patient, disease and surgical characteristics were collected and analyzed. Post-reimplantation prosthesis (PRP) survival was modeled using the Kaplan–Meier method. Cox proportional hazard modeling was then performed to identify risk factors associated with implant failure. Overall PRP survival was 82% in 140 unilateral TKAs. PRP survival between groups was 81%, 96% and 73% within the minimum 2-year follow-up period, respectively. There was a difference in median interval-to-reimplantation between groups (CBS, 72.0 days; NEW, 111.0 days; ACL, 84.0 days, p = 0.003). Adjusting for time-to-reimplantation, NEW spacers demonstrated greater PRP survival compared with ACL spacers (p = 0.044), and a trend towards greater survival compared with CBS spacers (p = 0.086). Excluding early failures (< 90 days), NEW spacers still demonstrated greater survival than ACL spacers (p = 0.046). Lower volume (≤ 10 within this series) surgeons tended to use more CBS spacers, while higher volume surgeons were comfortable with ACL spacers. There was greater PRP survival with NEW spacers. NEW spacers also demonstrated an increased inter-stage interval, likely because of increased comfort and motion. There were spacer choice differences between low- and high-volume surgeons. III.
On the (Non)Evolution of HI Disks over Cosmic Time

We present new results on the frequency distribution of projected HI column densities f(N,X), total comoving covering fraction, and integrated mass densities rho_HI of high redshift, HI `disks' from a survey of damped Lya systems (DLAs) in the Sloan Digital Sky Survey, Data Release 5. For the full sample spanning z=2.2 to 5 [738 DLAs], f(N,X) is well fitted by a double power-law with a break column density N_d = 10^(21.55 +/- 0.04) and low/high-end exponents alpha = -2.00 +/- 0.05, -6.4^{+1.1}_{-1.6}. The shape of f(N,X) is invariant during this redshift interval and also follows the projected surface density distribution of present-day HI disks as inferred from 21cm observations. We conclude that HI gas has been distributed in a self-similar fashion for the past 12Gyr. The normalization of f(N,X), in contrast, decreases by a factor of two during the ~2Gyr interval from z=4 to 2.2 giving corresponding decreases in both the total covering fraction and rho_HI. At z~2, these quantities match the present-day values suggesting no evolution during the past ~10Gyr. We argue that the evolution at early times is driven by `violent' processes that removes gas from nearly half the galaxies at z~3 establishing the antecedants of current early-type galaxies. The perceived constancy of rho_HI, meanwhile, implies that HI gas is a necessary but insufficient pre-condition for star formation and that the global star-formation rate is driven by the accretion and condensation of fresh gas from the intergalactic medium.
Development phase delineation in primeval European beech using the dominant biomass strata protocol

Abstract Reliable characterizations of developmental condition can help elucidate disturbance regimes, characterize structural development, and identify and describe old-growth. However, current forest life cycle development phase classifications are based on inconsistent, incompatible, or unreliable a priori archetypal structures that fail to capture the natural dynamics of old-growth European beech (Fagus sylvatica L.) forests subject to a small-scale disturbance regime. We demonstrate an alternative protocol for capturing phases of biomass upgrade based solely on the proportion of live-tree volume in seven progressive tree size classes, with an optional deadwood-share cut-off (30%) to also identify deadwood-rich patches when desired. The proportions of a 10-ha primeval European beech forest in the Ukraine assigned in 156.25 m2 grid cells to each of the Dominant Biomass Strata phases were in keeping with previously reported estimates. Amid a matrix (>60%) of Overstory, Upper Overstory, and Emergent phases, roughly a tenth of the area was classified to the early Open/Seedling and Understory phases, the Lower and Upper Midstory phases, and the Lower Overstory phase, respectively. Further, 12% of grid cells—across all phases—were deadwood-rich. The biomass proxies of live volume, basal area, and mean tree size increased distinctly with each subsequent phase, and were lower in the deadwood-rich category, in accordance with the forest life cycle. Structural complexity proxies varied inversely with biomass when defined as the distribution of volume among canopy layers, but similarly to biomass when defined using metrics based on tree size differences. High volumes of large-diameter deadwood were observed in all phases, consistent with previous observations of acyclic transitions following mortality. In pure primeval European beech, the synchronous pattern of biomass and size-based structural complexity metrics (including the standard deviation of tree diameters, the Gini coefficient for basal area, the diameter differentiation index T, and the structural complexity index SCI) may provide a natural model for the simultaneous optimization of volume and small-scale complexity in managed forests. With local adaptation, the proposed Dominant Biomass Strata classification protocol could be applicable to any site or forest type and used to classify stand development phases in young forests following stand-initiation or to classify patch development phases in old-growth forests subject to maintenance dynamics.
Sources of Variation

Why do data vary? When we measure GMAT scores, stock prices, or executive compensation, why don’t we get a constant value for each? Much of the statistical analysis of data focuses upon discovering sources of variation in data.
Hunting the Whale: More Evidence on State Government Leviathans

Caplan holds that governments are Leviathans, seeking to extend their power by increasing government expenditures beyond the level preferred by voters. We extend Caplan's model by examining the real (percentage) growth rates of government. We also examine whether government size increases at an increasing rate as the minority party weakens. We find evidence that supports and fails to support the original Leviathan hypothesis. We also fail to support our extensions of Caplan's hypothesis. Furthermore, our significant and contrary results have intuitively appealing interpretations. From these results, we conclude that the impact of political party power on government spending is ambiguous.
BDD-based conjunctive decomposition using a genetic algorithm and dependent variable affinity

Decomposition is an important strategy in synthesis and verification. BDD-based conjunctive decomposition has been successfully used in verification, especially in image computations for finite state machine (FSM) state-space traversals. Conjunction decomposition also has applications in other areas of CAD. A "two-step" algorithm for representing a large function as a conjunctive decomposition of BDDs is described where a genetic algorithm (GA) approach for ordering individual bit functions is given followed by an affinity-based clustering technique. Experimental results are given that show the effectiveness of the algorithm.
Total environmental management: An approach to the dilemmas of the affluent society

Abstract Many people are currently advocating a ‘no growth’ economy. By way of introduction, the author explains why and how this is so, and then points out that the objectives of conservation and economic growth can and should be seen as complementary. He advocates the application of the systems approach to the total fabric of our natural and social environments.
A Parallel Algorithm for the Dynamic Partitioning of Particle-Mesh Computational Systems

Particle trackingmethods are a versatile computational technique cen tral to thesim ulation of a wide range of scientic applications. In this paper we present a new parallel approach for the dynamic partitioning of particle-mesh computational systems. The approach uses a framework, the "in-element" particle tracking method, based on the assumption that particle trajectories are computed by problemdata localized to individual elements. The parallel efficiency of such particle-mesh systems dependson the partitioning of both the mesh elements and the particles; this distribution can change dramatically because of movement of the particles and adaptive refinement of the mesh. To address this problem we introduce a combined load function that is a function of both the particle and mesh element distributions. We present experiment results that detail the performance of this parallel load balancing approach for a three-dimensional particle-mesh test problem on an unstructured, adaptive mesh.
The enveloping algebra of the Lie superalgebra (1,2)

Let g be the Lie superalgebra osp(1, 2r) and U(g) the enveloping algebra of g. In this paper we obtain a description of the set of primitive ideals PrimU(g) as an ordered set. We also obtain the multiplicities of composition factors of Verma modules over U(g), and of simple highest weight modules forU(g) when regarded as a U(g0)-module by restriction. 0.1. Let g = g0 ⊕ g1 be a finite dimensional complex classical simple Lie superalgebra. In [M1] we showed that any primitive ideal in U(g) is the annihilator of a simple highest weight module L(λ), (see 0.2–0.5 for notation). To complete the description of the set of primitive ideals PrimU(g), it is necessary to say when two modules L(λ), L(μ) have the same annihilator. For Lie superalgebras of Type I, this was done in [L2] using a bijection between PrimU(g0) and PrimU(g). However this bijection does not preserve inclusions. In this paper we study the case where g = osp(1, 2r) and obtain a description of Prim U(g) as an ordered set. We also obtain the multiplicities of composition factor of Verma modules over U(g), and of L(λ) when regarded as a U(g0)-module by restriction. The orthosymplectic Lie superalgebra osp(V, β) may be defined as the Lie superalgebra of all linear operators on a Z2-graded vector space V preserving a nondegenerate even bilinear supersymmetric form β. We refer to [K1, 2.1.2] or [Sch, II. 4.3.A, page 129] for more details. In [M3] we give an alternative construction for g = osp(1, 2r) using the rth Weyl algebra. This leads to a construction of an analog of the Joseph ideal in U(g). There are several related reasons why we might expect U(g) to be structurally similar to U(g0) when g = osp(1, 2r). For example the Harish-Chandra map yields an isomorphism Z(g) ' S(h) , all weights in h∗ are typical, and all finite dimensional modules are completely reducible. The results of this paper tend to confirm this expectation. Some of the proofs in this paper work for Lie superalgebras other than osp(1, 2r). For example most results hold for typical representations of s`(r, 1). In order to state our results in greater detail, we introduce some notation. Received by the editors January 27, 1997 and, in revised form, July 25, 1997. 1991 Mathematics Subject Classification. Primary 17B35. Research partially supported by National Science Foundation grant DMS 9500486. c ©1997 American Mathematical Society
Start-ups and spin-outs: competitive strategies and effects on former employees

The authors present an empirical study of the positive and negative effects of start-ups and spin-outs, using a sample of 49 companies from a cross section of technology-based industries. These 49 start-ups are representative of venture capital backed companies in the 1970s and 1980s. The authors examine their circumstances at the times they were formed and their longer-term impact on their industries. Few cases in which the start-up might be judged as competing with a former employer (two out of 49) are found. In 16 cases the idea for the product had existed at a former employer, but it was pursued in only three of them. In almost 40% of the cases, both the start-ups and the former employer became leading firms in their industries. Overall, for this sample the benefits from start-ups and spin-outs are considerable, while the negative effects are minor. It is concluded that the new companies tend to move into new markets, not yet occupied by established companies, and even when they enter existing markets, they are seldom in the same market segment as the former employer. >
Grouping by proximity and the visual impression of approximate number in random dot arrays

We address the challenges of how to model human perceptual grouping in random dot arrays and how perceptual grouping affects human number estimation in these arrays. We introduce a modeling approach relying on a modified k-means clustering algorithm to formally describe human observers' grouping behavior. We found that a default grouping window size of approximately 4° of visual angle describes human grouping judgments across a range of random dot arrays (i.e., items within 4° are grouped together). This window size was highly consistent across observers and images, and was also stable across stimulus durations, suggesting that the k-means model captured a robust signature of perceptual grouping. Further, the k-means model outperformed other models (e.g., CODE) at describing human grouping behavior. Next, we found that the more the dots in a display are clustered together, the more human observers tend to underestimate the numerosity of the dots. We demonstrate that this effect is independent of density, and the modified k-means model can predict human observers' numerosity judgments and underestimation. Finally, we explored the robustness of the relationship between clustering and dot number underestimation and found that the effects of clustering remain, but are greatly reduced, when participants receive feedback on every trial. Together, this work suggests some promising avenues for formal models of human grouping behavior, and it highlights the importance of a 4° window of perceptual grouping. Lastly, it reveals a robust, somewhat plastic, relationship between perceptual grouping and number estimation.
Detonation wave propagation through a single orifice plate in a circular tube

Detonation behavior associated with the propagation of a detonation wave through an orifice plate located within a circular tube is investigated. The tube and orifice diameter used in the study are 27.3 cm and 10 cm, respectively. The test gas used is hydrogen-air at 1 atmosphere and at various initial temperatures up to 650 K. Immediately after the orifice, the detonation wave decouples and either fails or reinitiates. The reinitiation process is characterized by either spontaneous initiation, initiation due to shock reflection, or deflagration-to-detonation transition (DDT). In the case of DDT, transition is preceded by the degeneration of the decoupled detonation wave to a velocity consistent with a CJ deflagration. Delineation between these various propagation regimes could not be correlated with the detonation cell size, λ, and orifice diameter, d . The data, although limited, demonstrate for the first time that the d c /λ =13 critical tube criterion obtained at room temperature may not apply at elevated temperature conditions. The evidence for this is data obtained at 500 K that shows no detonation transmission for 30% hydrogen in air that corresponds to d/λ =16.7. The tests also indicate that a simple d/λ correlation cannot be used to determine when reinitiation due to shock reflection is possible. For example, at 650 K detonation wave failure was observed for d/λ d/λ
An analysis of magnetic cross-relaxation between water and methylene protons in a model system.

Experiments have been performed to demonstrate and quantify cross-relaxation between water and methylene resonances in a simple model system. Inversion recovery experiments on aqueous solutions of polyethylene glycol produce a transient nuclear Overhauser effect that alters the recovery of the methylene resonance. The relevant equations and parameters that describe this effect are identified and their values are explicitly quantified by analyzing the experimental results. It is shown that cross-relaxation is measurable and significant in this system even though there are no strong hydrophilic interactions available to immobilize water. In studies of dog bile, the water and lipid resonances behave in a qualitatively similar fashion, lending support to the contention that cross-relaxation cannot be neglected in solutions of biological macromolecules. © 1989 Academic Press, Inc.
The effect of daily administration of IL-18 on cardiac structure and function:

Recently, the cytokine Interleukin-18 (IL-18) has been shown to be increased as a result of cardiac surgery. Elevated IL-18 has been associated with neurological dysfunction, systemic inflammatory response syndrome (SIRS), and multiple organ dysfunction syndrome (MODS) post open-heart surgery. The intent of the study contained herein was to determine the effect of IL-18 administration on cardiac function and structure. Eight C57BL/6 female mice were treated daily with 0.5microg/mouse of recombinant IL-18 for 7 days. Long axis echocardiography (ECHO) measurements of the anatomical and hemodynamic function of the heart for all mice were studied 24h after the last dose. The left ventricular wet weights increased from 84 +/- 1 to 93 +/- 3 mg when comparing the placebo (n = 8) with the IL-18 groups, respectively (p = 0.01). With ECHO analysis, IL-18 significantly increased left ventricular (LV) mass, the left atrium dimensions (LA), and the left ventricular posterior wall thickness (LVPW) over the 8-day time period (p < 0.01). There was a 5-fold increase in interstitial cardiac collagen content and a 30% increase in myocyte size in the IL-18 compared with the control groups (p < 0.01). Administration of IL-18 appears to induce interstitial fibrosis and myocyte hypertrophy, resulting in increased ventricular stiffness. Thus, increased IL-18 during and post open-heart surgical procedures may induce left ventricular diastolic dysfunction and affect post-operative outcomes.
Cyber security: Threats, reasons, challenges, methodologies and state of the art solutions for industrial applications

Cyber Civilization has become an important source of information sharing and professional activities like business, banking transactions, shopping, services and advertisement. With the exponentially increase in usage of cyberspace, cybercriminal actives are also increase exponentially. The basic reasons is that with the inception of world wide web, the web applications were also getting popularity for data storing and data sharing, irrespective of the user. With the passage of time web applications were getting more complex with rapid increase in their design faults, creating the surfing of internet totally unsafe. More than 90 percent web applications have some kind of design or development fault which can be easily exploited by the cyber criminals. These faults in web application can help criminals in getting the illegal access to trade secrets of any business. Sometime the web application may not be posing threat but the technology used in these applications become the root cause and put the application to the risk of illegal access. Presently the social networks, Internet connected mobile devices, individual privacy, and the online connectivity of entities such as banks are the most enticing targets for cyber criminals. In this survey we highlight the common cyber threats and detailed analysis of existing system and methodology used for its industrial solutions. Some important some industrial application also analyzed this paper.
Polarizable water models: Vectorization of energy calculations on the CYBER 205

Abstract A large fraction of the time spent calculating the energy of a configuration of polarizable water molecules is spent calculating the electric field and polarization energy. This paper describes vectorization strategies for such calculations on the CYBER 205. For a cluster of 215 waters and the Lybrand-Kollman model, the vectorized calculation on the CYBER 205 executes at about 47 times VAX 8650 speed, or about 300 times VAX 11/780 speed.
Federal Antitrust Policy During the Kennedy-Johnson Years:

Tables and Figures Preface Introduction: A Brief History of Antitrust Policy to 1950 The Issue: Business Concentration in the 1950s and 1960s The Response: The Executive The Response: The Congress The Response: The Supreme Court Conclusions Epilogue Notes Appendix: A: Merger Guidelines, U.S. Department of Justice Appendix B: Report of the White House Task Force on Antitrust Policy Appendix C: Report on the Task Force of Productivity and Competition Appendix D: Directorships of Major U.S. Corporations Tightly Interlocked Glossary Selected Bibliography Index
Stereoselective synthesis of aryl γ,δ-unsaturated β-hydroxyesters by ketoreductases

Abstract The biocatalytic reduction of aryl γ , δ -unsaturated- β -ketoesters was evaluated utilizing 24 different commercially available ketoreductases. In all cases, both ( R ) and ( S )-enantiomers of γ , δ -unsaturated β -hydroxyesters were synthesized by one or more ketoreductases in excellent optical purity and yields.
Timing Error Compensator Design for Spiral Based Self-Servowriting in Disk Drives

Abstract This paper considers the timing error compensation problem for spiral based Self-Servowriting (SSW) process in disk drives manufacturing, wherein the product servo patterns are written based on the prewritten spiral tracks. The disk eccentricity and position error in the spiral tracks cause Repeatable Timing Error (RTE) which deteriorates the product servo pattern format and, as a result, the servo sectors are not uniformly distributed along the circular tracks. The spindle speed variation and sensor noise induce Non-repeatable Timing Error (NRTE) which results in phase incoherency at the servo sectors between adjacent tracks. In this paper, a Recursive Least Square (RLS) based Parameter Adaptive Algorithm (PAA) is proposed to estimate and cancel the RTE. An error shaping filter is designed to improve the estimation performance of PAA and reduce the effect of NRTE in the system. Finally, simulation studies using industry supplied data show the effectiveness of the proposed control scheme. The RTE can be cancelled up to 90% and the quality of the written servo sectors is improved by 91%.
Perceived control of asthma and quality of life among adults with asthma

Background Perceived control of certain chronic conditions influences health status outcomes. Objective To explore the impact of perceived control of asthma on asthma-specific and generic health status outcomes among adults with asthma. Perceived control was defined as individuals' perceptions of their ability to deal with asthma and its exacerbations. Methods Data were drawn from the baseline and first two followups of a longitudinal study of adults with asthma surveyed by telephone at 18-month intervals. An 11-item questionnaire (Perceived Control of Asthma Questionnaire [PCAQ]) was developed and validated. Results The PCAQ demonstrated high internal consistency (Cronbach's α = 0.79). Greater perceived control was associated with less severe asthma, greater asthma self-efficacy, lower perceived asthma severity, lower perceived danger from asthma, and greater perceived usefulness of asthma medicines. Greater perceived control was significantly associated with better asthma-specific quality of life concurrently and 18 and 36 months later, after controlling for demographics, smoking, and severity of asthma. Greater perceived control as also significantly associated with generic mental health outcomes concurrently and 18 and 36 months later, after controlling for covariates. Perceived control was associated with physical function concurrently and 18 months later, but not 36 months later. Conclusions The PCAQ is a reliable and valid measure of perceived control of asthma. Perceived control of asthma was associated with both asthma-specific and generic health status outcomes, concurrently and predictively. If perceived control could be modified, better outcomes, particularly better psychologic outcomes, might be achieved for individuals with asthma.
A characterization of the simple groupsPSL (2,p),p>3

LetG be a finite group, containing a self-centralizing subgroup of prime orderp. IfG is non-solvable, contains more than one class of conjugate elements of orderp, and satisfies an additional condition, thenG is isomorphic toPSL (2,p),p>3.
Severe anemia leading to hypodensity of cerebral venous sinuses on computed tomography imaging.

A previously healthy 7-month-old boy presented with new onset seizures. His physical examination was nonfocal. Initial laboratory evaluation was significant for hemoglobin 1.1 g/dL and hematocrit 3.8%. A head computed tomography (CT; Figure 1 ) showed hypodensity of the transverse sinuses bilaterally. Further evaluation resulted in a suspected diagnosis of Diamond Blackfan anemia. Subsequent brain magnetic resonance imaging showed multifocal ischemic infarcts. Figure 1. Computed tomography imaging demonstrating decreased attenuation in the transverse sinuses and torcula. The attenuation of blood on CT is primarily a function of the protein fraction of hemoglobin.1 A linear relationship has been established between hemoglobin levels and CT attenuation.2 Thus, in patients with elevated hematocrit due to polycythemia, for example, CT imaging may demonstrate hyperdensity within the cerebral vasculature.2,3 Conversely, very low hemoglobin levels may cause decreased attenuation of blood, making it appear less dense than brain on CT imaging1 and leading to the hypodensity seen in the transverse sinuses and torcula.
Improved accuracy of time-resolved micro-Particle Image Velocimetry using phase-correlation and confocal microscopy

Micro-Particle Image Velocimetry (μPIV) measurements often suffer from poor image quality because of volume illumination effects, out of focus particles, and low seeding densities. As a result, measurements are typically ensemble averaged in time to improve the signal-to-noise ratio (SNR) of the resulting cross correlations. To achieve reliable, time-accurate μPIV measurements we need to improve the SNR of the recorded images and/or the SNR treatment of the resulting cross correlations. In this paper, we improve image quality and cross correlation SNR by comparing the use of confocal microscopy with spectral filtering. Steady-state spatiotemporally resolved data from widefield and confocal μPIV experiments were used and cross correlations were performed using standard techniques and the Robust Phase Correlation (RPC) method that employs a PIV-optimized spectral filter on the cross-correlation planes. The accuracy improvements were assessed by comparison against the time-averaged ensemble cross correlation, which currently represents the most accurate and accepted approach for steady-state μPIV measurements. Results show 24.77 % erroneous vectors for two-pass standard cross correlation with widefield imaging, which was reduced to 9.08 % erroneous vectors when using the RPC and confocal imaging. Furthermore, a 59.2 % reduction of error referenced to the ensemble correlation was observed when using RPC with confocal imaging over baseline cases. Improvements seen for RPC and confocal cases result from synergistically improving the correlation signal-to-noise ratio, resulting in correlation planes with sharper primary peaks and lower background levels.
A multi-scale simulation method for high Reynolds number wall-bounded turbulent flows

We present an assessment and enhancement of the hybrid two-level large-eddy simulation method (A.G. Gungor and S. Menon, A new two-scale model for large eddy simulation of wall-bounded flows, Prog. Aerosp. Sci. 46 (2010), pp. 28–45), a multi-scale formulation for simulation of high Reynolds number wall-bounded turbulent flows. The assessment of the method is performed by examining role of static and dynamic blending functions used to perform hybridisation of two-level simulation (K. Kemenov and S. Menon, Explicit small-scale velocity simulation for high-Re turbulent flows, J. Comput. Phys. 220 (2006), pp. 290–311; K. Kemenov and S. Menon, Explicit small-scale velocity simulation for high-Re turbulent flows. Part 2: Non-homogeneous flows, J. Comput. Phys. 222 (2007), pp. 673–701) and large-eddy simulation methods. The sensitivity of first- and second-order turbulence statistics to the type of blending functions is investigated by simulating a fully developed turbulent flow in a channel at a friction Reynol...
Pharmacotherapy of depression in the elderly

Abstract Treatment of depression in the elderly must be based on careful differential diagnosis. Diagnostic pitfalls include considering sadness inherent to the aging process or mistaking depression for organic brain disease. The author briefly reviews the biochemistry of the tricyclics and its implications for choosing the best antidepressant for each patient. He recommends low dosages and thorough monitoring for side-effects in treating the elderly. The value of MAO inhibitors, lithium, stimulants, and ECT is also discussed. Pharmacotherapy should always be combined with some type of psychological support.
An Escherichia coli tyrosine transfer RNA is a leucine-specific transfer RNA in the yeast Saccharomyces cerevisiae.

Abstract While the Escherichia coli Su-3 (tyrT) tyrosine tRNA suppressor inserts only tyrosine at amber codons in E. coli, we show here that in Saccharomyces cerevisiae this tRNA inserts leucine and no significant amounts of any other amino acid. Thus, the E. coli tyrosine tRNA is functionally a leucine tRNA in yeast cytoplasm. This functional identity may correlate with a structural relationship between the E. coli tyrosine and yeast leucine tRNAs, which are both members of the uncommon type II class of tRNA structures. The results raise the possibility that in evolution a tRNA may be more closely related to a tRNA of different acceptor specificity, but of the same type class, than to one with the same amino acid specificity, but of a different type class.
An observational study of group waterpipe use in a natural environment.

introduction: To date research on tobacco smoking with a waterpipe (hookah, narghile, and shisha) has focused primarily on the individual user in a laboratory setting. Yet, waterpipe tobacco smoking is often a social practice that occurs in cafes, homes, and other natural settings. This observational study examined the behavior of waterpipe tobacco smokers and the social and contextual features of waterpipe use among groups in their natural environment. Methods: Trained observers visited urban waterpipe cafes on multiple occasions during an 8-month period. Observations of 241 individual users in naturally formed groups were made on smoking topography (puff frequency, duration, and interpuff interval [IPI]) and engagement in other activities (e.g., food and drink consumption, other tobacco use, and media viewing). r esults: Most users were male in group sizes of 3–4 persons, on average, and each table had 1 waterpipe, on average. The predominant social features during observational periods were conversation and nonalcoholic drinking. Greater puff number was associated with smaller group sizes and more waterpipes per group, while longer IPIs were associated with larger group sizes and fewer waterpipes per group. Additionally, greater puff frequency was observed during media viewing and in the absence of other tobacco use. conclusions: Overall, the results suggest that waterpipe smoking behavior is affected by group size and by certain social activities. Discussion focuses on how these findings enhance our understanding of factors that may influence exposure to waterpipe tobacco smoke toxicants in naturalistic environments.
The elite athlete and exercise in pregnancy

As the opportunities for women to compete in elite sports competition increase, it is inevitable that pregnancy will occur during training and competition. The effect of the high-intensity exercise needed to compete at the elite level will be found in anatomic changes such as ligament relaxation, change in posture, and increased weight. These will all detract from the ability to attain peak performance. The effect of the high-intensity training on the athlete and the fetus must also be considered. The physiological and metabolic changes will have a variable effect; however, awareness of these changes should prevent problems. There is some evidence suggesting an increase in low birthweight infants but no evidence of preterm birth. Unfortunately, much of our information is based on limited studies, so caution and careful evaluation are essential.
Computer controlled cutting of multiple identical joints in real rock

This novel method for reproducibly cutting joints in real rock will allow shearing of identical joints under varying stress paths. Shearing of such identical joints will greatly reduce the effect of sample variation and the need for scaling results.
Thyroid peroxidase-catalyzed iodination of thyroglobulin; inhibition by excess iodide.

Abstract Thyroid peroxidase-catalyzed iodination of thyroglobulin, BSA, and tyrosine at pH 7.0 is inhibited by concentrations of iodide exceeding 1 m m . At 10 m m iodide iodination is almost completely inhibited. These findings offer a possible explanation for previously reported inhibitory effects of large doses of iodide on thyroid hormone formation in rats (Wolff-Chaikoff effect) and in humans (iodide-induced myxedema). Several lines of evidence indicate that molecular iodine is not the active iodinating agent in the model peroxidase system. Iodide inhibition cannot, therefore, be attributed simply to the removal of I 2 by formation of I 3 − . Alternative possibilities for the mechanism of iodide inhibition are suggested.
Neurologic relapse after benzathine penicillin therapy for secondary syphilis in a patient with HIV infection.

TREPONEMA pallidum, the etiologic agent of syphilis, may be detected in the cerebrospinal fluid during early infection. The recommended therapeutic agent for primary, secondary, and latent syphilis...
Modeling seasonal influenza outbreak in a closed college campus: impact of pre-season vaccination, in-season vaccination and holidays/breaks.

Background College and university students experience substantial morbidity from influenza and influenza-like illness, and they can benefit substantially from vaccination. Public health authorities encourage vaccination not only before the influenza season but also into and even throughout the influenza season. We conducted the present study to assess the impact of various vaccination strategies including delayed (i.e., in-season) vaccination on influenza outbreaks on a college campus.
The inhibition of adenine nucleotide translocase activity by oleoyl CoA and its reversal in rat liver mitochondria.

The inhibitory effect of oleic acid on the 32Pi-ATP exchange activity and 14C-ADP translocation through the mitochondrial membrane can be reversed by substrates preferentially utilizing CoA and thereby preventing acylation of the fatty acid. By contrast the inhibition produced by oleoyl CoA can be reversed only when carnitine is added to augment oxidation of the CoA ester. The slow rate of respiration and sluggish response to ADP in oleoyl CoA treated mitochondria is overcome by the uncoupler, salicyl-anilide XIII. Inhibition of translocation of adenine nucleotides through the inner mitochondrial membrane by oleoyl CoA could regulate metabolism by inducing a transition from state 3 to state 4 respiration.
Improving Service Delivery in a Globally Competitive Environment

Quality service is becoming a critical weapon, even in developing countries, for maintaining and enhancing the competitive advantage of service firms. The globalisation of the service industry requires firms to assess their changing economic, competitive, legal and cultural environment and accelerate the development of strategies that include technology, coordinated systems, responsive employees and knowledgeable customers.
Eliminating order dependency of classification in artificial resonance theory (ART1) networks

ABSTRACT Incorrect classification of patterns can occur with ART1 networks when data are presented in certain sequences. The reason for this problem is the coding of the category templates, which are memory-less and give more importance to "l"s than to "O"s. This paper modifies the ART1 network architecture to alter these two featuresby adding a second set of top-down LTMs, in effect defining a second template. Computer simulations show thatthis modification ensures that patterns are always classified in the same category and that information is neverlost. As a result, no pre-processing of the data is necessary, and ART1 networks can be used to classify patternson-line without errors. 1 INTRODUCTION Adaptive Resonance Theory (ART) networks1'2 present the very appealing ability to learn continuously and inreal-time. They have been used for various applications, such as Speech Recognition and Image Processing. Thispaper concentrates on ART1 networks, which work with binary data. For certain types of input, the classificationobtained depends on the order of the input patterns presented to the network and pre-processing of the data isthen necessary. The problem has been studied by Rao and Gu4 and partially solved by Shih and Moh.5 Thispaper modifies the ART1 architecture to obtain a consistent classification independent of the order of the inputpatterns.A review of ART1 networks is first given and the source of the problem, namely the coding of the categorytemplate in the top-down LTMs, is delineated. The order dependency is then illustrated by a simple example. Anew architecture is presented and experimental results show its ability to solve the problem.
The complexity of monadic recursion schemes: exponential time bounds

Abstract We study the computational complexity of decision problems for the class M of monadic recursion schemes. By the “executability problem” for a class 't of monadic recursion schemes, we mean the problem of determining whether a given defined function symbol of a given scheme in .'t can be called during at least one computation. The executability problem for a class I of very simple monadic recursion schemes is shown to require deterministic exponential time. Using arguments about executability problems and about the class I , a number of decision problems for. M and for several of. M 's subclasses are shown to require deterministic exponential time. Deterministic exponential time upper bounds are also presented for several of these decision problems.
Zeros of holomorphic functions in balls

Abstract Let B denote the open unit ball in the space of n complex variables, where n > 1. A special case of the main result of the present paper is that the various Hardy spaces H p ( B ) (0 p B .
The Effects of Short-Term Exposure to an Endocrine Disrupter on Behavioral Consistency in Male Juvenile and Adult Siamese Fighting Fish

17α-Ethinyloestradiol (EE2) is known to impact courtship and aggression but how exposure affects the consistency with which individuals express these behaviors over time is not commonly addressed. In addition, how juvenile and adult male fish differ in levels of behavioral consistency, both before and after EE2 exposure, is unknown. To examine these questions, juvenile and adult male Siamese fighting fish were presented with a dummy male and dummy female simultaneously both before and after acute exposure to a nominal (15 ng/L) dose of EE2. Multiple trials were conducted to measure how consistent individual differences are affected by age and EE2 exposure. Both female- and male-directed behaviors decreased after short-term exposure to EE2. Juvenile and adult fish differed in the number of female-directed tail beats and bites they performed, with adult fish performing more tail beats and juvenile fish performing more bites. EE2 exposure had a greater effect on consistent individual differences in female-directed than in male-directed behaviors, which may be a byproduct of intense artificial selection for aggression in this species. Repeatability values were lower both before and after exposure in juvenile than in adult fish, suggesting that individuals become more consistent with age. This study suggests that male Siamese fighting fish vary in their sensitivity to short-term EE2 exposure and stresses the importance of examining behavior over multiple time points both within and across age classes to gain a more thorough understanding of the effects of endocrine disruptors on behavior.
420 X420 Charge-Coupled-Device Imager And Four-Chip Hybrid Focal Plane

We have designed and fabricated a 420 X420 pixel front-illuminated CCD imager. The device was designed to be used both individually and as part of a four-chip focal plane consisting of four chips closely abutted in a 2 X 2 array, for a total resolution of 840 X 840 pixels. Particular attention has been paid to achieving low-noise operation, and noise levels of less than 20 e- at a 1.0 MHz data rate have been achieved routinely. We describe special focal plane assembly techniques with which we have achieved 1 um relative positional accuracy between the chips.
Synopsis of Canotia (Celastraceae) Including a New Species from the Chihuahuan Desert

Canotia, a genus of holacanthoid shrubs of southwestern United States and northern Mexico, is redescribed, and reasons are advanced for retaining it in the family Celastraceae. Two species are recognized, includingC. wendtii sp. nov. from Chihuahua.