cssi/SciSciGPT-SciSciNet huggingface dataset:
Prostaglandin H synthase and hydroperoxides: Peroxidase reaction and inactivation kinetics

Abstract The reaction kinetics of the peroxidase activity of prostaglandin H synthase have been examined with 15-hydroperoxyeicosatetraenoic acid and hydrogen peroxide as substrates and tetramethylphenylenediamine as cosubstrate. The apparent K m and V max values for both hydroperoxides were found to increase linearly with the cosubstrate concentration. The overall reaction kinetics could be interpreted in terms of an initial reaction of the synthase with hydroperoxide to form an intermediate equivalent to horseradish peroxidase Compound I, followed by reduction of this intermediate by cosubstrate to regenerate the resting enzyme. The rate constants estimated for the generation of synthase Compound I were 7.1 × 10 7 m −1 s −1 with the lipid hydroperoxide and 9.1 × 10 4 m −1 s −1 with hydrogen peroxide. The rate constants estimated for the rate-determining step in the regeneration of resting enzyme by cosubstrate were 9.2 × 10 6 m −1 s −1 in the case of the reaction with lipid hydroperoxide and 3.5 × 10 6 m −1 s −1 in the case of reaction with hydrogen peroxide. The intrinsic affinities of the synthase peroxidase for substrate ( K s ) were estimated to be on the order of 10 −8 m for lipid hydroperoxide and 10 −5 m for hydrogen peroxide. These affinities are quite similar to the reported affinities of the synthase for these hydroperoxides as activators of the cyclooxygenase. The peroxidase activity was found to be progressively inactivated during the peroxidase reaction. The rate of inactivation of the peroxidase was increased by increases in hydroperoxide level, and decreased by increases in peroxidase cosubstrate. The inactivation of the peroxidase appeared to occur by a hydroperoxide-dependent process, originating from synthase Compound I or Compound II.
A review of the literature on potential reproductive and developmental toxicity of electric and magnetic fields.

The potential of electric and magnetic fields to adversely affect the health of the human population is an issue which continues to receive a great deal of attention in both public and scientific forums. One of the critical issues is the possibility that such fields may adversely affect the reproductive process. Numerous studies investigating the potential of electric and/or magnetic fields to alter reproduction in vertebrates have been conducted. These studies have, in many instances, yielded seemingly contradictory results. A number of epidemiological studies have been conducted as well. This review of the literature examines relevant studies and attempts to draw biologically rational conclusions from them. The studies are ordered in broad categories based upon both classification of the species studied (i.e. submammalian, mammalian exclusive of man and human) and the agent used (i.e. extremely low frequency electric, very low frequency electric, and magnetic fields). From our review we conclude that laboratory experimental and epidemiological results to date have not yielded conclusive data to support the contention that such fields induce adverse reproductive effects under the test or environmental conditions studied. Additional studies may, however, be warranted to clarify some of the experimental results obtained.
Ultrasonic diffraction in the design of photoacoustic probes

In this work, we examine the role of diffraction in the design of ring-shaped ultrasonic receivers for photoacoustic probes. The sensitivity patterns of ultrasonic receiving rings are calculated at 1 MHz using the angular spectrum technique. Three separate series of simulations are considered: flat ring with a fixed outer diameter and a variable inner diameter, flat ring with a fixed inner diameter and variable outer diameter, and a spherically focused ring with a variable inner diameter. From these results the focal zone characteristic and sensitivities are calculated. For the planar rings, we find that the spatial sensitivity varies markedly with ring width but the overall sensitivities are comparable. For the focused (spherically curved) rings, the focal distances and beam volumes were similar while the sensitivity grew with ring thickness.
High temperature structural silicides

Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi{sub 2}-based materials, which are borderline ceramic-intermetallic compounds. MoSi{sub 2} single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi{sub 2} possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi{sub 2}-Si{sub 3}N{sub 4} composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi{sub 2}-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing.
USP22 regulates cell proliferation by deubiquitinating the transcriptional regulator FBP1

Ubiquitin-specific protease 22 (USP22) edits the histone code by deubiquitinating H2A and H2B as part of the mammalian SAGA (Spt-Ada-Gcn5) complex, and is required for transcriptional regulation and normal cell-cycle progression. Here, we show that USP22 affects the expression of p21 by altering far upstream element (FUSE)-binding protein 1 (FBP1) ubiquitination, as ablation of USP22 leads to increased FBP1 ubiquitination and decreased FBP1 protein occupancy at the p21 gene. Surprisingly, increased polyubiquitination of FBP1 does not alter its protein stability, but instead modulates the stable recruitment of FBP1 to target loci. Our results indicate a mechanism by which USP22 regulates cell proliferation and tumorigenesis.
Tutors and Pupils: International Organizations, Central European Elites, and Western Models

In the past decade, political elites in Central and Eastern Europe have often sought to imitate Western organizational and institutional models, while organizations like the EU and NATO have often acted as “institutional tutors” in the region. Using evidence from Hungary and the Czech Republic, this paper demonstrates why imitating Western structures has been both administratively expedient and useful in building political coalitions. It also stresses that the short-term benefits of doing so are followed by longer-term costs. The paper answers four questions: How have certain models been held up to CEE elites? Why might some such models be targets for elites to imitate? How does such imitation occur? And what results from imitation? Contrary to expectations that institutional modeling would be merely technocratic and used only yearly in the transformation, the paper's threefold heuristic of templates, thresholds, and adjustments shows that the process is both politically contentious and sustained.
Political instability in Africa: A rent-seeking approach

The foregoing analysis developed the paradigm of self-interest motivated revolutionary activities. In effect, the construct presented differs from the by-product theory developed by Tullock only in its specific modeling of government-created rents as the engine which drives the violent political behavior. The empirical test of the positive relationship between rent creation by the government and the amount of destabilizing political activity yields strong support for the structuring of politically destabilizing activities as rent-seeking in nature. It is the authors' hope that further empirical investigation and a more general and rigorous modeling of revolution as a rent-seeking activity will become an important part of the literature in public choice.
Temperature dependence of resistance of amorphous metal-metal solids with wide composition ranges

Abstract We have studied the electrical resistance of a number of binary amorphous transition-metal (e.g. Fe-Ti) solids made by sputtering. By varying the composition, the temperature dependence changes systematically, allowing various contributions to be elucidated. For the non-magnetic samples, the data can be quantitatively described by aT - b ln(T2 + B2). For the magnetic samples, it is necessary to include a Kondo term, which is not responsible for minima at high temperatures.
Length-dependent changes in contractile dynamics are blunted due to cardiac myosin binding protein-C ablation

Enhanced cardiac contractile function with increased sarcomere length (SL) is, in part, mediated by a decrease in the radial distance between myosin heads and actin. The radial disposition of myosin heads relative to actin is modulated by cardiac myosin binding protein-C (cMyBP-C), suggesting that cMyBP-C contributes to the length-dependent activation (LDA) in the myocardium. However, the precise roles of cMyBP-C in modulating cardiac LDA are unclear. To determine the impact of cMyBP-C on LDA, we measured isometric force, myofilament Ca2+-sensitivity (pCa50) and length-dependent changes in kinetic parameters of cross-bridge (XB) relaxation (krel), and recruitment (kdf) due to rapid stretch, as well as the rate of force redevelopment (ktr) in response to a large slack-restretch maneuver in skinned ventricular multicellular preparations isolated from the hearts of wild-type (WT) and cMyBP-C knockout (KO) mice, at SL’s 1.9µm or 2.1µm. Our results show that maximal force was not significantly different between KO and WT preparations but length-dependent increase in pCa50 was attenuated in the KO preparations. pCa50 was not significantly different between WT and KO preparations at long SL (5.82±0.02 in WT vs. 5.87±0.02 in KO), whereas pCa50 was significantly different between WT and KO preparations at short SL (5.71±0.02 in WT vs. 5.80±0.01 in KO; p<0.05). The ktr, measured at half-maximal Ca2+-activation, was significantly accelerated at short SL in WT preparations (8.74±0.56s-1at 1.9µm vs. 5.71±0.40s-1at 2.1µm, p<0.05). Furthermore, krel and kdf were accelerated by 32% and 50%, respectively at short SL in WT preparations. In contrast, ktr was not altered by changes in SL in KO preparations (8.03±0.54s-1at 1.9µm vs. 8.90±0.37s-1at 2.1µm). Similarly, KO preparations did not exhibit length-dependent changes in krel and kdf. Collectively, our data implicate cMyBP-C is an important regulator of LDA via its impact on dynamic XB behavior due to changes in SL.
Education as “the Great Equalizer”: Health Benefits for Black and White Adults†

Objective Many social policies and academic studies assume that education is “the great equalizer” that is capable of counteracting the unequal social resources of different demographic groups. This study aims to determine whether non-Hispanic whites and racial/ethnic minorities indeed experience comparable health benefits with greater educational attainment. Methods Data from the National Health Interview Survey 1997–2012 were used to conduct ordered logistic models comparing the self-rated health of 518,288 non-Hispanic whites and racial/ethnic minorities aged 30–65 across the full spectrum of educational attainment. Results Educational attainment was found to affect the health of whites more than minorities, even with the inclusion of a wide range of potential sociodemographic, behavioral, and economic mediators. Conclusion We discuss the possibility that unmeasured variables, such as childhood environment and other individual characteristics, are responsible for the stronger effect of education for whites than minorities, and what the implications are for future policy and research.
Maskelynite-hosted apatite in the Chassigny meteorite: Insights into late-stage magmatic volatile evolution in martian magmas

Apatite-hosting maskelynite and alkali maskelynite within regions interstitial to cumulus olivine differ compositionally from that found within melt inclusions in the Chassigny martian meteorite. Feldspar glass compositions within the interstitial regions evolve along a high-temperature crystallization path. Within the melt inclusions, feldspar glass shows evolution to low temperatures, extending into the subsolidus regime. Coupled with these differences in maskelynite compositions are differences in volatile abundance in apatite included within the maskelynite. Apatite found within the large olivine-hosted polyphase melt inclusions is uniformly fluorapatite, whereas that interstitial to cumulus olivine is chlor-fluorapatite. We propose that the differences in maskelynite and apatite compositions within the melt inclusion and interstitial regions arose primarily from different crystallization conditions. Melt-inclusion maskelynite and apatite are consistent with nearly closed-system buildup of magmatic volatiles during crystallization within the melt inclusions, exsolution of a Cl-bearing fluid phase, and retention of this fluid phase within the melt inclusions into the hydrothermal regime. For the interstitial regions, however, the higher solidus temperatures of the interstitial melts, the early crystallization of feldspar with significant ternary component, and the Cl-rich nature of the apatite, all suggest open-system fluid migration through the cumulus pile, ingress of Cl-rich, H2O-poor brine from a hotter, less evolved portion of the magma plumbing system, and interaction of this Cl-rich fluid with melt prior to the crystallization of feldspar. Such processes of fluid migration through a cumulus pile have been suggested on Earth in layered intrusions, and apatite is the primary recorder of this process.
Isolated accessory mitral valve: identification and anatomic description using 3D transesophageal echocardiography.

A 50-year-old man, with an asymptomatic cardiac murmur, was referred for transesophageal echocardiography (TEE). A prior transthoracic echocardiogram (TTE) reported an elongated, mobile, mass-like structure adjacent to the aortic valve, for which endocarditis was suspected and ruled out. On both two-dimensional (2D) ( Panel A ) and three-dimensional (3D) ( Panel B and Supplementary data online, Video S1 ) TEE, a leaflet-like, mobile structure (arrows) was seen within the left ventricular outflow tract (LVOT), with attachment at the base, on the left ventricular side, of …
HspBP1, an Hsp70 Cochaperone, Has Two Structural Domains and Is Capable of Altering the Conformation of the Hsp70 ATPase Domain

We present here the first structural information for HspBP1, an Hsp70 cochaperone. Using circular dichroism, HspBP1 was determined to be 35% helical. Although HspBP1 is encoded by seven exons, limited proteolysis shows that it has only two structural domains. Domain I, amino acids 1–83, is largely unstructured. Domain II, amino acids 84–359, is predicted to be 43% helical using circular dichroism. Using limited proteolysis we have also shown that HspBP1 association changes the conformation of the ATPase domain of Hsp70. Only domain II of HspBP1 is required to bring about this conformational change. Truncation mutants of HspBP1 were tested for their ability to inhibit the renaturation of luciferase and bind to Hsp70 in reticulocyte lysate. A carboxyl terminal truncation mutant that was slightly longer than domain I was inactive in these assays, but domain II was sufficient to perform both functions. Domain II was less active than full-length HspBP1 in these assays, and addition of amino acids from domain I improved both functions. These studies show that HspBP1 domain II can bind Hsp70, change the conformation of the ATPase domain, and inhibit Hsp70-associated protein folding.
Tobacco craving predicts lapse to smoking among adolescent smokers in cessation treatment.

Previous research indicates that tobacco craving predicts relapse to smoking among adult smokers attempting to quit. We hypothesized a similar relationship between craving and lapse (any smoking following a period of abstinence) among adolescent smokers during the treatment phase of a clinical trial. A visit was considered a lapse visit if the participant reported smoking or had a carbon monoxide level of 7 ppm or greater subsequent to an abstinent visit. A total of 34 participants (mean age = 14.9 years [SD = 1.3]; mean cigarettes/day = 18.0 [SD = 7.6]; mean Fagerstrom Test for Nicotine Dependence score = 6.8 [SD = 1.34]; 65% female), were included in the present analysis of 167 treatment visits. Logistic regression analyses showed a positive relationship between degree of craving, measured by the Questionnaire on Smoking Urges, and lapse during smoking cessation treatment (p = .013). Additionally, linear regression analyses demonstrated a strong positive association between cigarettes smoked per day and craving scores (p<.001). Taken together with other data, these findings suggest that degree of craving might influence tobacco abstinence for adolescent smokers. Thus monitoring and addressing craving appears useful to increase the success of adolescent smoking cessation.
Translocation positive acute myeloid leukemia associated with valproic acid therapy

Valproic acid is an effective anti-epileptic medication often used for long-term control of seizure disorders that has been implicated in hematological toxicities, including rare reports of myelodysplasia and acute leukemia. Here, we report a case of valproic acid-related leukemia-like syndrome with a t(8;16) chromosomal translocation. After discontinuing valproic acid, the hematological findings completely resolved.
Relationships between network parameters and the performance of distributed adaptive-routing algorithms using learning automata in packet-switched datagram networks

Large computer networks with dynamic links present special problems in adaptive routing. If the rate of change in the network links is fairly rapid and the changes are nonperiodic, then obtaining the optimal solution for adaptive routing becomes complex and expensive. In addition to the academic value of the solution, the growth of computer networks gives the problem practical importance. Learning automata is logical approach to the above problem. With the right parameter values, learning automata can converge arbitrarily close to the solution for a given network topology and set of conditions. The adaptability of automata reduces the depth of analysis needed for network behavior; the survivability and robustness of the network is also enhanced. Finally, each automaton behaves independently, making automata ideal for distributed decision-making, and minimizing the need for inter-node communication. Previous work on automata and network routing do not address how changes in network parameter values affect the performance of automata-based adaptive routing. Such knowledge is essential if we are to determine the suitability of an automata-based routing algorithm for a given network. Our paper focuses on this question and shows that in packet- switched datagram networks, relationships do indeed exist between network parameters and the performance of distributed adaptive routing algorithms. Additionally, our paper compares the performance and behavior of several types of learning automata, as well as changes in automata behavior over a range of reward and penalty values. Finally, the performance of two automata-based adaptive routing algorithms is compared. Our automaton model is a stochastic, linear, S-model automaton. In other words, the automaton's matrix of action probabilities changes as a result of performance feedback which it receives from the environment, the response to environment feedback is linear, and finally, the feedback it receives from the environment is over a continuous interval.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Drugs and prolactin.

Medications commonly cause hyperprolactinemia and their use must be differentiated from pathologic causes. The most common medications to cause hyperprolactinemia are the antipsychotic agents, although some of the newer atypical antipsychotics do not do so. Other medications causing hyperprolactinemia include antidepressants, antihypertensive agents, and drugs which increase bowel motility. Often, the medication-induced hyperprolactinemia is symptomatic, causing galactorrhea, menstrual disturbance, and erectile dysfunction. In the individual patient, it is important differentiate hyperprolactinemia due to a medication from a structural lesion in the hypothalamic–pituitary area. This can be done by stopping the medication temporarily to determine if the prolactin (PRL) levels return to normal, switching to another medication in the same class which does not cause hyperprolactinemia (in consultation with the patient’s physician and/or psychiatrist), or by performing an MRI or CT scan. If the hyperprolactinemia is symptomatic, management strategies include switching to an alternative medication which does not cause hyperprolactinemia, using estrogen/testosterone replacement, or cautiously adding a dopamine agonist.
Enhanced sensitivity and stability in two-color in situ hybridization by means of a novel chromagenic substrate combination

Double in situ hybridization analysis is a fundamental technique for studying the expression of two genes with high temporal and spatial resolution. However, due to the lack of sensitivity in current detection methods, this approach is powerful only when at least one transcript is abundantly expressed. Here, we report a new enzyme/chromagenic substrate combination that provides sufficient sensitivity for detecting two less abundant transcripts and stability for subsequent paraffin sectioning.
An Arabidopsis VPS45p Homolog Implicated in Protein Transport to the Vacuole

The Sec1p family of proteins is required for vesicle-mediated protein trafficking between various organelles of the endomembrane system. This family includes Vps45p, which is required for transport to the vacuole in yeast (Saccharomyces cerevisiae). We have isolated a cDNA encoding a VPS45 homolog from Arabidopsis thaliana (AtVPS45). The cDNA is able to complement both the temperature-sensitive growth defect and the vacuolar-targeting defect of a yeast vps45 mutant, indicating that the two proteins are functionally related. AtVPS45p is a peripheral membrane protein that associates with microsomal membranes. Sucrose-density gradient fractionation demonstrated that AtVPS45p co-fractionates with AtELP, a potential vacuolar protein sorting receptor, implying that they may reside on the same membrane populations. These results indicate that AtVPS45p is likely to function in the transport of proteins to the vacuole in plants.
Effect of Cu adsorption on the tungsten (100) surface resonance

It has recently been observed that adsorbed Au and Hg do not quench the W (100) surface resonance up to monolayer coverage. We report here that Cu does quench the W (100) surface resonance at θ≧0.5 monolayers. This suggests that the effective potential of Cu differs more strongly from that of W than do the effective potentials of Au or Hg.
Turning modes of production inside out: or, why capitalism is a transformation of slavery

Marxist theory has by now largely abandoned the (seriously flawed) notion of the ‘mode of production’, but doing so has only encouraged a trend to abandon much of what was radical about it and naturalize capitalist categories. This article argues a better conceived notion of a mode of production - one that recognizes the primacy of human production, and hence a more sophisticated notion of materialism - might still have something to show us: notably, that capitalism, or at least industrial capitalism, has far more in common with, and is historically more closely linked with, chattel slavery than most of us had ever imagined.
Influence of configurational changes on the superconducting transition temperature of an amorphous zirconium-nickel alloy

The reversible thermal relaxation found in various amorphous materials has been observed in the glassy metal-metal alloy Zr/sub 76/Ni/sub 24/. The superconducting transition temperature, T/sub c/, can increase reversibly in this alloy with increasing temperature of anneal T/sub a/ for T/sub a/ or =300 /sup 0/C an irreversible decrease in T/sub c/ occurs. The effect of plastic deformation on T/sub c/ appears to be identical to the effect of heat treatment. It is speculated that high temperatures need not be produced during deformation, but rather that stress fields encourage the same atomic-scale relaxation processes which are active in thermal annealing.
Iron oxide-based honeycomb catalysts for the dehydrogenation of ethylbenzene to styrene

Abstract Corning has recently developed a novel extrusion method to make bulk transition metal oxide honeycomb catalysts. One area of effort has been iron oxide-based catalysts for the dehydrogenation of ethylbenzene to styrene, a major chemical process that yields worldwide 20 MM tons/yr. In industry, the monomer is synthesized mostly in radial-flow fixed-bed reactors. Because of the high cross-sectional area for flow and shallow depth of the catalyst bed in these reactors, low reactor pressure gradients are maintained that favors the yield and selectivity for styrene formation. However, the radial-flow design has inherent detractions, including inefficient use of reactor volume and large temperature gradients that decrease catalyst service life. The overall economics of the process can be improved with parallel-channel honeycomb catalysts and axial flow reactors. The simple axial flow design of honeycomb catalysts provides low-pressure drop, while making more efficient use of reactor volume, with better heat and mass transfer characteristics compared to a conventional radial packed bed. An important part of this concept is the ability to fabricate a wide family of dehydrogenation catalyst compositions into honeycombs with the requisite chemical, physical, mechanical, and catalytic properties for industrial use. The ethylbenzene dehydrogenation (EBD) honeycomb catalysts developed by Corning have compositions similar to those commonly used in industry and are prepared with the same catalyst and promoter precursors and with similar treatments. However, to enable extrusion of catalyst precursors into honeycomb shapes, especially at cell densities above 100 cell/in. 2 , Corning’s process compensates for the high salt concentrations and the high pH of the batch material that would otherwise prevent or impede honeycomb extrusion. The improved rheological characteristics provide the necessary plasticity, lubricity, and resiliency for honeycomb extrusion with sufficient binder strength needed before calcination to the final product. Iron oxide-based honeycombs after calcination are strong and possess macroporosity and high surface area. In bench-scale testing, particular honeycomb catalyst compositions exhibited 60–76% ethylbenzene conversion with styrene selectivity of 95–91%, respectively, under conventional reaction conditions without apparent deactivation or loss of mechanical integrity.
Software implementations of division and square root operations for Intel® Itanium® processors

Division and square root are basic operations defined by the IEEE Standard 754-1985 for Binary Floating-Point Arithmetic [1], and are implemented in hardware in most modern processors. In recent years however, software implementations of these operations have become competitive. The first IEEE-correct implementations in software of the division and square root operations in a mainstream processor appeared in the 1980s [2]. Since then, several major processor architectures adopted similar solutions for division and square root algorithms, including the Intel® Itanium® Processor Family (IPF). Since the first software algorithms for division and square root were designed and used, improved algorithms were found and complete correctness proofs were carried out. It is maybe possible to improve these algorithms even further.The present paper gives an overview of the IEEE-correct division and square root algorithms for Itanium processors. As examples, a few algorithms for single precision are presented and properties used in proving their IEEE correctness are stated. Non-IEEE variants, less accurate but faster, of the division, square root and also reciprocal and reciprocal square root operations are discussed. Finally, accuracy and performance numbers are given. The algorithms presented here are inlined by the Intel and other compilers for IPF, whenever division and square root operations are performed.
Impact of the QQQ on liquidity and risk of the underlying stocks

Abstract We test the impact of QQQ creation on the liquidity and risk of the component securities, particularly whether the liquidity effect is asymmetric depending on the QQQ component weight. We find that liquidity of the underlying stocks improves following creation of the QQQ and that the improvement is more pronounced for less heavily weighted stocks. We also find that systematic risk of the underlying stocks declines relative to a control sample. The findings are consistent with Merton's (Merton, R., 1987. A simple model of capital market equilibrium with incomplete information. Journal of Finance, 42 , 483–510) Investor Recognition Theory and may offer implications about the effects of continued ETF creation on the market microstructure for underlying stocks.
An integral-spectral approach for reacting Poiseuille flows

An integral-spectral formulation for laminar reacting flows in tubular geometry (tubular Poiseuille flows) is introduced and performed within an operator–theoretic frame-work where the original convective-diffusive differential transport problem coupled with reaction is inverted to give an integral equation. This equation is of second kind and of the Volterra type with respect to the axial coordinate of the tube with a kernel given by Green's function. Green's function is identified by a methodology that gives the Mercier spectral expansion in terms of eigenvalues and eigenfunctions of the Sturm–Liouville problem in the radial variable of the tube. Eigenvalue problems for both Dirichlet and von Neumann boundary conditions are solved in terms of analytical functions (Poiseuille functions) and compared with the values found in the literature. The groundwork is set for future applications of the methodology to solving a wide variety of problems in convective–diffusive transport and reaction. Examples with wall and bulk chemical reaction are given to illustrate the technique.
Effects of Chemical Defense Antidotes (Atropine) on Aviator Performance (Simulated Flight and Zero Input Tracking Analyzer)

Army aviation is at serious risk in chemical and biological warfare environments. One of the potential countermeasures for aviators against the chemical threat is the development of antidote and pretreatment drugs. Just as the chemical agent carries the threat of degrading aviator performance, antidote and pretreatment drugs could independently produce problems either alone or in combination with an agent. This paper briefly outlines part of the first phase of a systematic program using controlled, simulated flight conditions and a Zero Input Tracking Analyzer (ZITA) to identify and measure flight performance and psychomotor effects of unchallenged atropine (one of the chemical defense antidotes) on aviators. Each of 12 U.S. Army helicopter aviators voluntarily received 3 dosages: 0 mg (saline solution), 2 mg of atropine sulfate, and 4 mg of atropine sulfate. Results indicate that simulator flight performance data did prove to be sensitive in identifying and measuring effects of 4 mg of atropine. Addition...
On skew Toeplitz operations, I

This paper is concerned with the study of the invertibility properties of a certain class of operators which we call “skew Toeplitz”. Besides being of mathematical interest, these operators appear quite frequently in engineering applications. Our results will also be seen to be closely related to the classical theory of Hankel and Toeplitz operators. We wish to acknowledge the pioneering influence of Professor Livsic in the uses of operator theory in systems which was an inspiration for the present work.
Dephasing and quantum localization in disordered systems.

Comparaison de deux theories autocoherentes de la fonction de Green pour la localisation: theorie de Abou-Chaera, Anderson, et Thouless (AAT) et l'approximation du dephasage effectif. On montre que, en contradiction avec les exigences recentes, l'energie propre de l'equation AAT represente la relaxation de la population (processus T 1 ) moins que le dephasage pur (processus T 2 )
Remarks on the Feynman representation

On montre qu'il existe un espace complet ∂L 1 (M t K , M t D ) des fonctions integrables tel que pour un potentiel V a borne H 0 nulle relative a l'operateur hamiltonien libre H 0 d'un systeme quantique non relativiste fini, la fonction exp[−i∫ 0 t V 0 X s ds] appartient a ∂L 1 (M t K , M t D ), et la representation de Feynman est valable
Experiencing Blues at the Crossroads: A Place-Based Method for Teaching the Geography of Blues Culture

Abstract This article offers a pedagogical module that explores the geography of blues culture across the Mississippi Delta. By focusing on blues culture, rather than simply blues music itself, this project provides a forum for understanding the broader geographical conditions from which this musical form emerged. This module utilizes place-based methodologies and musical expressions as lenses to understand the influences that migration and cultural diffusion have had on the evolution of Delta blues. The impacts these processes had on diffusing African cultural legacies and setting the stage for the evolution of the civil rights movement are considered.
Devolatilization rates and intraparticle wave structures during the combustion of pulverized coals and polymethylmethacrylate

Minimum explosive concentrations (lean limits) for dust particles of bituminous coal and polymethylmethacrylate (PMMA) in air were measured as a function of particle size. For fine particles, limits are essentially independent of particle size because finer particles can fully devolatilize within the flame front. Propagation is then homogeneously controlled, and lean limits for the fine dusts occur at the same minimum concentration of combustible volatiles as the lean limits for homogeneous mixtures. A size dependence appears for coarser particles above some characteristic diameter (50 μm for the coal, 100 μm for PMMA) because total particle devolatilization is not possible within the flame front. Lean limit concentrations increase rapidly above those characteristic diameters because more dust per unit volume is needed to compensate for the smaller fraction of each dust particle that contributes volatiles to the flame. As diameters increase still further, a critical size is soon reached above which the dust is nonexplosive. The particle size dependence for the minimum explosive concentration is thus determined by the devolatilization rate process. Those devolatilization rates were independently measured for coals and PMMA using a laser beam to simulate the flame front heating fluxes. Microscopic structure data for partially devolatilized coal particles reveal the inevitable presence of an intraprticle devolatilization wave front. Exposed sharp corners, peaks, or ridges of the coal particles are observed to devolatilize well before a contiguous wave front is established over the entire surface. Data were obtained for PMMA which confirm the presence of such a heat-transport-controlled devolatilization wave structure. Surface temperature measurements for PMMA further indicate bubble mass transport limitations at low heating fluxes. For the coals, such mass transport limitations may play a more significant role. The observed laser devolatilization rates, when extrapolated to equivalent flame heating fluxes and particles residence times within the flame front, give predictions of lean limit characteristic diameters that are in reasonable agreement with the data.
Inhibition of TAP by pseudorabies virus is independent of its vhs activity

Previously we have shown that pseudorabies virus (PrV) down-regulates the expression of porcine MHC class I molecules by interfering with the transporter associated with antigen processing (TAP). During lytic PrV infection, the half-lives of both host and viral mRNA are regulated by the product of virion host shut-off (vhs) gene, UL41. PrV vhs protein induces degradation of cellular mRNA including those encoding class I and TAP. Therefore, further elucidation of specific mechanisms of down-regulation of class I molecules by PrV necessitates construction of a vhs deletion mutant. Two such mutants (vhsDelta1 and vhsDelta2) were generated by homologous recombination between the wild type (wt) PrV Indiana-F strain, and plasmids containing truncated UL41 gene of PrV into which the enhanced green fluorescent protein (EGFP) cassette was inserted. Compared with the wt virus, both the vhs mutants exhibited slower in vitro growth kinetics. The mutants, like the wt virus, inhibited the peptide transport activity of TAP and down-regulated cell surface expression of class I molecules. These findings suggest that, inhibition of TAP activity in PrV-infected cells is due to mechanism(s) specifically directed at class I pathway and not due to the non-specific vhs activity of the virus.
Association of physical performance measures with bone mineral density in postmenopausal women.

Abstract Lindsey C, Brownbill RA, Bohannon RA, Ilich JZ. Association of physical performance measures with bone mineral density in postmenopausal women. Arch Phys Med Rehabil 2005;86:1102–7. Objective To investigate the association between physical performance measures and bone mineral density (BMD) in older women. Design Cross-sectional analysis. Setting University research laboratory. Participants Healthy postmenopausal women (N=116; mean age ± standard deviation, 68.3±6.8y) in self-reported good health who were not taking medications known to affect bone, including hormone replacement therapy. Interventions Not applicable. Main Outcome Measures Anthropometrics and BMD of the hip, spine, whole body, and forearm. Physical performance measures included normal and brisk 8-m gait speed, normal step length (NSL), brisk step length (BSL), timed 1-leg stance (OLS), timed sit-to-stand (STS), and grip strength. Results NSL, BSL, normal gait speed, brisk gait speed, OLS, and grip strength correlated significantly with several skeletal sites ( r range, .19–.38; P R 2 range, .11–.24; P P Conclusions Normal and brisk gait speed, NSL, BSL, OLS, and grip strength are all associated with BMD at the whole body, hip, spine, and forearm. Physical performance evaluation may help with osteoporosis prevention and treatment programs for postmenopausal women when bone density scores have not been obtained or are unavailable.
A Composite Diagnosis of Synoptic-Scale Extratropical Cyclone Development over the United States

This paper presents a composite diagnosis of synoptic-scale forcing mechanisms associated with extratropical cyclone evolution. Drawn from 12 cyclone cases that occurred over the continental United States during the cool season months, the diagnosis provides a 'climatology' of development mechanisms for difference categories of cyclone evolution ranging from cyclone weakening through three stages of cyclone intensification. Computational results were obtained using an 'extended' form of the Zwack-Okossi equation applied to routine upper-air and surface data analyzed on a 230 km x 230 km grid. Results show that cyclonic vorticity advection, which maximizes in the upper troposphere, was the primary contributor to cyclone development regardless of the stage of development. A second consistent contributor to development was latent heat release. Horizontal temperature advection, often acknowledged as a development mechanism, was found to contribute to development only during more intense stages. During weakening and weaker development stages, temperature advection opposed development, as the warm-air advection invariably found at upper levels was dominated by cold air advection in the lower half of the troposphere. In the more intense stages, development was moderated by dry-adiabatic cooling associated with the ascending vertical motions.
The buoyant titration of bovine serum mercaptalbumin I. An interpretation in terms of ion binding

Abstract The buoyant density of bovine serum mercaptalbumin was measured in CsCl throughout the pH range 5.0–12.5. The buoyant densities were found to increase gradually until a sharp increase was noted at pH 10.5. These data were analyzed in terms of changes in water and salt binding as the ionizable amino acid residues titrate. The recent data of Foster were used to compute the charge on the molecule as a function of pH. A generalized equation expressing the buoyant density was combined with the condition that the molecule be electrically neutral to yield the number of Cs + and Cl − bound as a function of pH. The results indicate a generalized increase and decrease in the number of Cs + and Cl − , respectively, bound as the pH is raised from the isoelectric pH of 5.3 to pH 9.5. As the pH continues to rise, a large increase in the number of Cs + bound is noted as the tyrosines are ionized, and a sharp decrease in the number of Cl − bound as the lysine residues are deprotonated.
Double-layer prostheses for repair of abdominal wall defects in a rabbit model.

Abstract The primary objective of this study was to compare the effectiveness of expanded polytetrafluoroethylene (e-PTFE) and polypropylene (PPM) in a rabbit abdominal wall defect model using a double-layer repair technique. Fifty-four New Zealand white rabbits had full thickness resection of a 5 × 5-cm segment of the mid portion of at the abdominal wall. The defect was repaired with two 6 × 6-cm layers of prosthesis in an underlay/overlay fashion incorporating a 1 -cm edge of abdominal wall and grouped accordingly. Group I: inner and outer layer of PPM; Group II: inner layer e-PTFE, outer layer PPM; Group III: inner and outer layer e-PTFE. Animals from each group were sacrificed at 3, 6, and 12 months. The abdominal wall was assessed for herniations and bowel adhesions to the inner layer of the prosthesis. Adhesions were graded according to an adhesion scoring system (grade 0-3). No herniations were observed. Intestinal adhesions to PPM were quite dense at 3 months with a mean adhesion score of 2.5; at 12 months, adhesions were more dense and extensive, having a mean score of 3. Adhesions to e-PTFE were thin and filmy with a mean score of 0.4 at 3 months and 0.6 at 12 months ( P
Friedel—crafts reactions catalyzed by polystyrenetricarbonylmolybdenum

Abstract The heterogeneous catalyst polystyrenetricarbonylmolybdenum, like its homogeneous counterpart, catalyzes Friedel—Crafts reactions. Whereas the polymeranchored tricarbonylmolybdenum shows decreased activity with respect to the homogeneous system, its selectivity toward para substitution is high and it can be reused several times without loss of activity. Exchange and leaching experiments on the catalyst indicate that the tricarbonylmolybdenum group remains attached to the polystyrene support during the course of catalysis. The results are in accord with the contention made for the homogenous system that complete dissociation of the arene ring from molybdenum does not occur in the active form of the catalyst.
Using 1/f noise to examine planning and control in a discrete aiming task

The present study used 1/f noise to examine how spatial, physical, and timing constraints affect planning and control processes in aiming. Participants moved objects of different masses to different distances at preferred speed (Experiment 1) and as quickly as possible (Experiment 2). Power spectral density, standardized dispersion, rescaled range, and an autoregressive fractionally integrated moving average (ARFIMA) model selection procedure were used to quantify 1/f noise. Measures from all four analyses were in reasonable agreement, with more ARFIMA (long-range) models selected at peak velocity in Experiment 1 and fewer selected at peak velocity in Experiment 2. There also was a nonsignificant trend where, at preferred speed, of those participants who showed 1/f noise, more tended to show 1/f noise at peak velocity, when planning and control would overlap most. This trend disappeared for fast movements, where planning and control would have less time to overlap. Summing short-range processes at different timescales can produce 1/f-like noise. As planning is a slower-moving process and control faster, present results suggest that, with enough time for both planning and control, 1/f noise in aiming may arise from a similar summation of processes. Potential limitations of time series length in the present task are discussed.
Lasers in the management of calcified urinary tract stents

Indwelling double J ureteral stents are used for internal urinary diversion for ureteral obstruction and post-surgical drainage of the upper urinary tract. Stent calcification is a serious complication especially in those with forgotten stents. In a retrospective review of 16 patients (10 male and 6 female) we found holmium laser to be highly effective in the management of calcified stents. Encrustations/calcifications were noted on the distal end of the sent in 6 patiens (37.5%), middle and distal portions in 2 patients (12.5%), along the entire length of the stent in 3 patients (18.75%), lower portion of the stent in 4 patients (25%) and at the upper and lower ends of the stent in one patient (6.25%). Cystolitholapaxy, retrograde ureteroscopy (URS) with holmium: YAG (yttrium-aluminum-garnet) laser intracorporeal lithotripsy, percutaneous nephrostolithotomy (PNL) and antegrade URS with holmium: YAG laser intracorporeal lithotripsy were effectively performed without intraoperative complications. Lithotripsy became necessary before stent removal in 11 patients (68.75%). Holmium laser lithotripsy was useful in managing 7 patients (43.75%), and shockwave lithotripsy (SWL) in 6 patients (37.5%). In two patients (12.5%) both holmium and SWL were used before the stent can be removed.
Validating Coherence Measurements Using Aligned and Unaligned Coherence Functions

This paper describes a novel approach based on the use of coherence functions and statistical theory for sensor validation in a harsh environment. By the use of aligned and unaligned coherence functions and statistical theory one can test for sensor degradation, total sensor failure or changes in the signal. This advanced diagnostic approach and the novel data processing methodology discussed provides a single number that conveys this information. This number as calculated with standard statistical procedures for comparing the means of two distributions is compared with results obtained using Yuen's robust statistical method to create confidence intervals. Examination of experimental data from Kulite pressure transducers mounted in a Pratt & Whitney PW4098 combustor using spectrum analysis methods on aligned and unaligned time histories has verified the effectiveness of the proposed method. All the procedures produce good results which demonstrates how robust the technique is.