cssi/SciSciGPT-SciSciNet huggingface dataset:
Timing of fetal nucleated red blood cell count elevation in response to acute hypoxia

An association between intrauterine hypoxia and increased nucleated red blood cell (RBC) counts in the peripheral circulation has long been acknowledged. Higher counts reportedly are especially likely in neurologically impaired newborn infants. This study aimed at determining the effect of acute, severe hypoxia on peripheral nucleated RBC counts in the fetal rat. Maternal animals were randomized to either 2 hours of exposure in a hypoxia chamber or exposure to room air in a control chamber. The test chamber contained 9% oxygen, 3% carbon dioxide, and balanced nitrogen. Cesarean deliveries were carried out immediately after exposure and then at intervals up to 60 hours. There were 56 fetuses in each group. No differences in nucleated RBC counts were apparent immediately after hypoxic exposure, but counts were significantly higher in the hypoxia group 12 and 24 hours after exposure. Counts in the 2 groups did not differ significantly 36, 48, or 60 hours after exposure. Like in studies of the human fetus, nucleated RBC counts decreased with advancing fetal age. Near-term fetal rats in this study exhibited a delayed but transient increase in nucleated RBC counts in the peripheral circulation after an acute hypoxic episode. It may be that an increased nucleated RBC count will be a useful marker for fetal brain injury of hypoxic origin.
Dial M for flavor symmetry breaking

We introduce a realization of Seiberg duality in MQCD that does not involve moving branes. Using related arguments in M Theory and IIA, we investigate the flavor symmetry breaking via flavored magnetic monopole condensation of hep-th/0005076. We verify our results by considering visualizations of M5 branes corresponding to N = 2 vacua which survive soft breaking by an adjoint mass term.
Rationality and intelligence

The long-term goal of our field is the creation and understanding of intelligence. Productive research in AI, both practical and theoretical, benefits from a notion of intelligence that is precise enough to allow the cumulative development of robust systems and general results. The concept of rational agency has long been considered a leading candidate to fulfill this role. This paper outlines a gradual evolution in the formal conception of rationality that brings it closer to our informal conception of intelligence and simultaneously reduces the gap between theory and practice. Some directions for future research are indicated.
Outer Planets Atmospheric Entry Probes; Science Objectives and Payloads

The scientific objectives of atmospheric entry probes are to characterize the physical structure of the atmosphere and to determine its chemical composition/The structural properties of the atmosphere are determined with a combination of triaxial accelerometers and temperature and pressure gages. The atmospheric thermal balance is measured with a net flux radiometer. The identity and relative abundance of the chemical constituents of the atmosphere are obtained by a mass spectrometer and a gas chrojnatograph. The cloud layers are located with a nephelometer. The operating characteristics of these instruments are described and the use of the data to increase our knowledge of the outer planets is indicated.
Reasons to act and believe: naturalism and rational justification in Hume’s philosophical project

Is Hume a naturalist? Does he regard all or nearly all beliefs and actions as rationally unjustified? In order to settle these questions, it is necessary to examine their key terms (‘naturalism’ and ‘rational justification’) and to understand the character—especially the normative character—of Hume’s philosophical project. This paper argues (i) that Hume is a naturalist—and, in particular, both a moral and an epistemic naturalist—in quite robust ways; and (ii) that Hume can properly regard many actions and beliefs as “rationally justified” in several different senses of that term.
Plane stress stable crack growth and J-integral/HRR field

Abstract Moire interferometry with line densities of 1200 and 40 lines per mm was used to determine the two orthogonal displacements surrounding a stably extending crack in a 2024-T3 aluminum alloy, single edge cracked specimen. The test protocol consisted of using the fine moire grating prior to and up to the onset of crack extension and the coarse moire grating for the ensuing crack extension up to Δa = 6 mm. The displacement fields were used to compute the J-integrals for various contours during crack tip blunting and crack extension. As expected, the far-field J-integral value prior to stable crack growth coincided with the LEFM strain energy release rate G, and validated the experimental procedure. However, the J values obtained from the near tip contour increased slowly, while the far-field J values increased rapidly with increasing stable crack growth. The HRR displacement field was computed from the experimentally determined far-field J. The HRR displacement field agreed with the measured displacement field prior to stable crack growth since J = G. However, the HRR horizontal displacement field progressively deviated from the measured values with crack extension.
The geometry and generation of NC tool paths

Numerically controlled milling is the primary method for generating complex die surfaces. These complex surfaces are generated by a milling cutter which removes material as it traces out pre-specified tool paths. The accuracy of tool paths directly affects the accuracy of the manufactured surface. The geometry and spacing of the tool paths impact the scallop height and time of manufacturing respectively. In this paper we propose a new method for generating NC tool paths. This method gives the part programmer direct control over the scallop height of the manufactured surface. The method also provides options to the part programmer for generating a variety of tool paths based on practical metrics such as tool path length, tool path curvature and number of tool retractions.
The handling qualities simulation program for the augmentor wing jet STOL research aircraft

Aircraft have been simulated on computers for a variety of reasons. The training of pilots and crews on operational flight trainers, for example, is a common use of simulation. Subsystems of aircraft are often simulated to firm up the design of the hardware and frequently the whole aircraft must be simulated to help in the design of the subsystems. This is the case in the simulation of the Augmentor Wing Jet STOL Research Aircraft, a modified de Havilland C8-A Buffalo, in which the total aircraft was simulated to determine final design values for control systems and devices which augment control of the aircraft. For research and development simulations such as this one, simulation software and hardware must have general application while in piloted "man-in-the-loop" simulations speed of computation is the overriding concern. Thus the aircraft model and computer software and hardware must be merged to provide an accurate simulation which meets the needs of the research objectives.
Processing and Characterization of Porous TiO2 Coatings

Titania coatings were prepared by spin coating anhydrous titanium ethoxide solutions onto Si substrates. During deposition, Ti ethoxide in the solution layer reacted with atmospheric moisture to form precipitated particles. The resulting microstructures were composed of a network of particles and particle clusters. The induction time for precipitation, the particle diameter, and the size and packing of particle clusters were influenced by the Ti concentration in the sol and the spinning rate used for deposition. Individual particle sizes ranged from [approximately]150 to 250 nm. Smaller particles and more compact particle clusters were characteristic of coatings prepared from solutions with lower Ti concentrations and those prepared using faster spinning rates. As-deposited coatings were amorphous and crystallized into the anatase phase at [approximately]400C. Transformation to the rutile phase began at [approximately]850C, and the transformation rate was influenced by the microstructure.
The neighborhood complex of a random graph

For a graph G, the neighborhood complex N[G] is the simplicial complex having all subsets of vertices with a common neighbor as its faces. It is a well-known result of Lovasz that if @?N[G]@? is k-connected, then the chromatic number of G is at least k+3. We prove that the connectivity of the neighborhood complex of a random graph is tightly concentrated, almost always between 1/2 and 2/3 of the expected clique number. We also show that the number of dimensions of nontrivial homology is almost always small, O(logd), compared to the expected dimension d of the complex itself.
Expanding the Scope of Cinchona Alkaloid-Catalyzed Enantioselective α-Aminations of Oxindoles: A Versatile Approach to Optically Active 3-Amino-2-oxindole Derivatives

A cinchona alkaloid-catalyzed, highly enantioselective, α-amination of oxindoles has been developed. The reaction is general, operationally simple, and affords the desired products in high yields with good to excellent enantioselectivity. Significantly, this study provides a general catalytic method for the construction of a C−N bond at the C3 position of oxindoles as well as for the creation of a nitrogen-containing, tetrasubstituted chiral center.
Positive knots and Lagrangian fillability

This paper explores the relationship between the existence of an exact embedded Lagrangian filling for a Legendrian knot in the standard contact $\rr^3$ and the hierarchy of positive, strongly quasi-positive, and quasi-positive knots. On one hand, results of Eliashberg and especially Boileau and Orevkov show that every Legendrian knot with an exact, embedded Lagrangian filling is quasi-positive. On the other hand, we show that if a knot type is positive, then it has a Legendrian representative with an exact embedded Lagrangian filling. Further, we produce examples that show that strong quasi-positivity and fillability are independent conditions.
Products in Hochschild cohomology and Grothendieck rings of group crossed products

Abstract We give a general construction of rings graded by the conjugacy classes of a finite group. Some examples of our construction are the Hochschild cohomology ring of a finite group algebra, the Grothendieck ring of the Drinfel'd double of a group, and the orbifold cohomology ring for a global quotient. We generalize the first two examples by deriving product formulas for the Hochschild cohomology ring of a group crossed product and for the Grothendieck ring of an abelian extension of Hopf algebras. Our results account for similarities in the product structures among these examples.
Exploring reaction outcomes through the reactivity-selectivity principle estimated by density functional theory studies

Publisher Summary In organic chemistry the utilization of reactivity-sensitivity has been mainly to explain the outcome for chemical reactions. The more reactive the reagent is, the less selective it is in the reactions. The explanation for the reactivity–activity principle is that the more reactive the reagent is, the more likely it will react at every collision. The less reactive the reagent is, the more the electronic distribution in the substrate will play a part, thereby resulting in more discrimination at the various positions. This picture of reactivity–selectivity is useful if the information on the electronic distribution of both reactant and substrates is available. The most reliable qualitative results can be obtained for a particular reaction series when an increase of the reactivity of the reactant will result in a corresponding decrease in selectivity of that species. The observation of a reactivity–selectivity relationship for a given reaction series suggests certain uniformity in the mechanism while a sudden break or the total failure suggests the opposite. In this chapter, the usefulness of computational approaches to evaluate reactivity–selectivity with a particular emphasis on using density functional theory computational methods is focused upon. They have been shown by many to be highly reliable for the computation of the structures and energies of chemical systems. The goal is to demonstrate that computational tools are useful for exploring organic reaction mechanisms, and if properly used, will produce reliable results. The chapter discusses computational methodology, basics for the reactivity–selectivity approach, the Diels–Alder reaction, ring opening reactions, radical reactions, and reactivity and stability of carbocations. Selectivity is the difference of reactivity for the same reactant for two concurrent reactions. It has been demonstrated that frontier orbital interactions, spin and charge distribution, as well as bond orders, are helpful properties for evaluation of chemical reactivity and selectivity.
Nonlinear distortion free fiber-based chirped pulse amplification with self-phase modulation up to 2π

By using an electo-optic phase modulator to realize nonlinear phase pre-compensation, we demonstrate nonlinear distortion free fiber-based chirped pulse amplification with accumulated self-phase modulation up to 2.0 π radians.
Counterintuitive Behavior of Social Systems

This paper addresses several social concerns: population trends; quality of urban life; policies for urban growth; and the unexpected, ineffective, or detrimental results often generated by government programs. Society becomes frustrated as repeated attacks on deficiencies in social systems lead only to worse symptoms. Legislation is debated and passed with great hope, but many programs prove to be ineffective. Results are often far short of expectations. Because dynamic behavior of social systems is not understood, government programs often cause exactly the reverse of desired results. The field of system dynamics now can explain how such contrary results happen. Fundamental reasons cause people to misjudge behavior of social systems. Orderly processes in creating human judgment and intuition lead people to wrong decisions when faced with complex and highly interacting systems. Until we reach a much better public understanding of social systems, attempts to develop corrective programs for social troubles will continue to be disappointing. This paper cautions against continuing to depend on the same past approaches that have led to present feelings of frustration. New methods developed over the last 30 years will lead to a better understanding of social systems and thereby to more effective policies for guiding the future.
Synthesis of Acridines by the [4 + 2] Annulation of Arynes and 2-Aminoaryl Ketones

The reaction of 2-aminoaryl ketones and arynes generated by the treatment of various o-(trimethylsilyl)aryl triflates with CsF results in [4 + 2] annulation to afford substituted acridines in good yields.
Penetrating Ocular Injuries

Penetrating ocular and orbital trauma present the emergency medicine physician with ongoing challenges. A suspicion of their occurrence with understanding and prompt recognition of presenting signs ultimately will give the patient the best possible visual outcome.
String junctions for arbitrary Lie-algebra representations☆

Abstract We consider string junctions with endpoints on a set of branes of IIB string theory defining an ADE -type gauge Lie algebra. We show how to characterize uniquely equivalence classes of junctions related by string/brane crossing through invariant charges that count the effective number of prongs ending on each brane. Each equivalence class defines a point on a lattice of junctions. We define a metric on this lattice arising from the intersection pairing of junctions, and use self-intersection to identify junctions in the adjoint and fundamental representations of all ADE algebras. This information suffices to determine the relation between junction lattices and the Lie-algebra weight lattices. Arbitrary representations are built by allowing junctions with asymptotic ( p , q ) charges, on which the group of conjugacy classes of representations is represented additively. One can view the ( p , q ) asymptotic charges as Dynkin labels associated to two new fundamental weight vectors.
ON THE STICKINESS PROPERTY

Guasoni (2006) reported the no-arbitrage conditions for markets with proportional transaction costs. In the framework of Guasoni (2006), an investor can invest in an asset X that is a cadlag (a Fre...
Rotational excitation of symmetric top molecules by collisions with atoms: Close coupling, coupled states, and effective potential calculations for NH3–He

The formalism for describing rotational excitation in collisions between symmetric top rigid rotors and spherical atoms is presented both within the accurate quantum close coupling framework and also the coupled states approximation of McGuire and Kouri and the effective potential approximation of Rabitz. Calculations are reported for thermal energy NH3-He collisions, treating NH3 as a rigid rotor and employing a uniform electron gas (Gordon-Kim) approximation for the intermolecular potential. Coupled states are found to be in nearly quantitative agreement with close coupling results while the effective potential method is found to be at least qualitatively correct. Modifications necessary to treat the inversion motion in NH3 are discussed.
Spherical alterations of handles: embedding the manifold plus construction

Quillen’s famous plus construction plays an important role in many aspects of manifold topology. In our own work [Geometry and Topology 7 (2006) 541–556] on ends of open manifolds, an ability to embed cobordisms provided by the plus construction into the manifolds being studied was a key to completing the main structure theorem. In this paper we develop a “spherical modification” trick that allows for a constructive approach to obtaining those embeddings. More importantly, this approach can be used to obtain more general embedding results. In this paper we develop generalizations of the plus construction (together with the corresponding group-theoretic notions) and show how those cobordisms can be embedded in manifolds satisfying appropriate fundamental group properties. Results obtained here are motivated by, and play an important role in, our ongoing study of noncompact manifolds.
Self-Doped Ti3+ Enhanced Photocatalyst for Hydrogen Production under Visible Light

Through a facile one-step combustion method, partially reduced TiO2 has been synthesized. Electron paramagnetic resonance (EPR) spectra confirm the presence of Ti3+ in the bulk of an as-prepared sample. The UV−vis spectra show that the Ti3+ here extends the photoresponse of TiO2 from the UV to the visible light region, which leads to high visible-light photocatalytic activity for the generation of hydrogen gas from water. It is worth noting that the Ti3+ sites in the sample are highly stable in air or water under irradiation and the photocatalyst can be repeatedly used without degradation in the activity.
Effectiveness of Diesel Oxidation Catalyst in Reducing HC and CO Emissions from Reactivity Controlled Compression Ignition

Reactivity Controlled Compression Ignition (RCCI) has been shown to allow for diesel-like or better brake thermal efficiency with significant reductions in nitrogen oxide (NOX) particulate matter (PM) emissions. Hydrocarbon (HC) and carbon monoxide (CO) emission levels, on the other hand, are similar to those of port fuel injected gasoline engines. The higher HC and CO emissions combined with the lower exhaust temperatures with RCCI operation present a challenge for current exhaust aftertreatments. The reduction of HC and CO emissions in a lean environment is typically achieved with an oxidation catalyst. In this work, several diesel oxidation catalysts (DOC) with different precious metal loadings were evaluated for effectiveness to control HC and CO emissions from RCCI combustion in a light-duty multi-cylinder engine operating on gasoline and diesel fuels. Each catalyst was evaluated in a steady-state engine operation with temperatures ranging from 160 to 260 C. A shift to a higher light-off temperature was observed during the RCCI operation. In addition to the steady-state experiments, the performances of the DOCs were evaluated during multi-mode engine operation by switching from diesel-like combustion at higher exhaust temperature and low HC/CO emissions to RCCI combustion at lower temperature and higher HC/CO emissions. High CO andmore » HC emissions from RCCI generated an exotherm keeping the catalyst above the light-off temperature.« less
Strong-coupling expansions for chiral models of electroweak symmetry breaking

Abstract We consider chiral U ( N ) × U ( N ) models with fermions in the limit of infinitely large local bare Yukawa coupling. When the scalar field is subject to non-linear constraint, phase transitions in these models are seen to be identical to those in the corresponding purely bosonic ones. Relaxing the non-linear constraint, we compute the seventh-order strong-coupling series for the susceptibility in these models and analyze them numerically for the U (2) × U (2) case. We find that in four dimensions the approach to the phase transition follows to a good accuracy the mean-field critical behavior, indicating the absence of non-trivial fixed points at strong coupling and being consistent with the first-order nature of the transition. In three dimensions, the strongly-coupled bosonic U (2) × U (2) model (without gauge fields) has a first-order transition strong enough to accommodate electroweak baryogenesis only for a narrow region of the bare parameter space.
Reaction Mechanisms for Methane Ignition

To help understand how methane ignition occurs in gas turbines, dual-fuel diesel engines, and other combustion devices, the present study addresses reaction mechanisms with the objective of predicting autoignition times for temperatures between 1000 K and 2000 K, pressures between 1 bar and 150 bar and equivalence ratio between 0.4 and 3. It extends our previous methane flame chemistry and refines earlier methane ignition work. In addition to a detailed mechanism, short mechanisms are presented that retain essential features of the detailed mechanism. The detailed mechanism consists of 127 elementary reactions among 31 species and results in nine intermediate species being most important in autoignition, namely, CH 3 , OH, HO 2 , H 2 O 2 , CH 2 O, CHO, CH 3 O, H, O. Below 1300 K the last three of these are unimportant, but above 1400 K all are significant. To further simplify the computation, systematically reduced chemistry is developed, and an analytical solution for ignition delay times is obtained in the low-temperature range. For most fuels, a single Arrhenius fit for the ignition delay is adequate, but for hydrogen the temperature sensitivity becomes stronger at low temperatures. The present study predicts that, contrary to hydrogen, for methane the temperature sensitivity of the autoignition delay becomes stronger at high temperatures, above 1400 K, and weaker at low temperatures, below 1300 K. Predictions are in good agreement with shock-tube experiments. The results may be employed to estimate ignition delay times in practical combustors.
Shaped Beams For Integrated Circuit Fabrication

Numerous types of electron-beam lithography systems have been designed and built over the years. The variable shaped probe with vector deflection type has emerged as the most common of the recent designs. This architecture's popularity stems primarily from the superior writing speed for any given resolution and dose requirement by virtue of the ability to expose numerous pattern elements in parallel while at the same time retaining the flexibility of digital pattern description. High currents for rapid registration mark acquisition and relatively low circuit speed requirements are also advantages of the variable shaped spot vector deflection design.
Intermolecular zirconium-catalyzed hydrophosphination of alkenes and dienes with primary phosphines.

Catalytic hydrophosphination of terminal alkenes and dienes with primary phosphines (RPH2; R = Cy, Ph) under mild conditions has been demonstrated using a zirconium complex, [κ5-N,N,N,N,C-(Me3SiNCH2CH2)2NCH2CH2NSiMe2CH]Zr (1). Exclusively anti-Markovnikov functionalized products were observed, and the catalysis is selective for either the secondary or tertiary phosphine (i.e., double hydrophosphination) products, depending on reaction conditions. The utility of the secondary phosphine products as substrates for further elaboration was demonstrated with a platinum-catalyzed asymmetric alkylation reaction.
Elastic Waves in Exterior Domains Part II: Global Existence with a Null Structure

In this paper, we prove that solutions to a problem in nonlinear elasticity corresponding to small initial displacements exist globally in the exterior of a nontrapping obstacle. The medium is assumed to be homogeneous, isotropic, and hyperelastic, and the nonlinearity is assumed to satisfy a null condition. The techniques contained herein would allow for more complicated geometries provided that there is a sufficient decay of local energy for the linearized problem.
Dichloroacetic acid accelerates initial development of 2-cell murine embryos in vitro

Preimplantation embryos up to the 8-cell stage of development use lactate and pyruvate but not glucose or Krebs cycle intermediates to support growth, development, and cleavage. The dominant effect of dichloroacetic acid (DCA) is the irreversible stimulation of pyruvate dehydrogenase (PDH) activity, thus accelerating the oxidative metabolism of pyruvate and lactate. To test the hypothesis that early induction of oxidative metabolism in 2-cell murine embryos accelerates preimplantation embryo cleavage rates, female B6C3F1 mice at 6 to 8 weeks of age were superovulated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) and mated. All 2-cell stage embryos were randomly assigned to culture media with or without 130 micrograms/mL DCA. The developmental stage of all embryos was then noted every 24 hours for a total of 72 hours. Chi-square analysis and the method of average rank sum were used to compare the distribution of embryos at each observation point. At 24 hours, DCA-exposed embryos had achieved an advanced stage of growth and development relative to controls (average rank sum, P = .026; chi-square distribution, P = .047). Subsequently, at 48 and 72 hours, neither the average rank sum nor the chi-square distribution was different. Our data suggest that DCA accelerates early growth and development of murine embryos before implantation, possibly through the early induction of oxidative metabolism.
Sterile neutrino decay and the LSND experiment

We propose a new explanation of the intriguing LSND evidence for electron antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a coupling with a light scalar and light (mostly active) neutrinos. We perform a fit to the LSND data, as well as all relevant null-result experiments, taking into account the distortion of the spectrum due to decay. By requiring a coupling g ~ 10−5, a heavy neutrino mass m4 ~ 100 keV and a mixing with muon neutrinos |Uµ4|2 ~ 10−2, we show that this model explains all existing data evading constraints that disfavor standard (3 + 1) neutrino models.
NEAR-INFRARED SPECTROSCOPY OF TROJAN ASTEROIDS: EVIDENCE FOR TWO COMPOSITIONAL GROUPS

The Trojan asteroids, a very substantial population of primitive bodies trapped in Jupiter's stable Lagrange regions, remain quite poorly understood. Because they occupy these orbits, the physical properties of Trojans provide a unique perspective on the chemical and dynamical processes that shaped the Solar System. The current study was therefore undertaken to investigate surface compositions of these objects. We present 66 new near-infrared (NIR; 0.7-2.5??m) spectra of 58 Trojan asteroids, including members of both the leading and trailing swarms. We also include in the analysis previously published NIR spectra of 13 Trojans (3 of which overlap with the new sample). This data set permits not only a direct search for compositional signatures, but also a search for patterns that may reveal clues to the origin of the Trojans. We do not report any confirmed absorption features in the new spectra. Analysis of the spectral slopes, however, reveals an interesting bimodality among the NIR data. The two spectral groups identified appear to be equally abundant in the leading and trailing swarms. The spectral groups are not a result of family membership; they occur in the background, non-family population. The average albedos of the two groups are the same within uncertainties (0.051 ? 0.016 and 0.055 ? 0.016). No correlations between spectral slope and any other physical or orbital parameter are detected, with the exception of a possible weak correlation with inclination among the less-red spectral group. The NIR spectral groups are consistent with a similar bimodality previously suggested among visible colors and spectra. Synthesizing the present results with previously published properties of Trojans, we conclude that the two spectral groups represent objects with different intrinsic compositions. We further suggest that whereas the less-red group originated near Jupiter or in the main asteroid belt, the redder spectral group originated farther out in the Solar System. If this suggestion is correct, the Trojan swarms offer the most readily accessible large reservoir of Kuiper Belt material as well as a unique reservoir for the study of material from the middle part of the solar nebula.
Does Active Substance Use at Housing Entry Impair Outcomes in Supported Housing for Chronically Homeless Persons

Objective:Recent clinical and policy trends have favored low-demand housing (provision of housing not contingent on alcohol and drug abstinence) in assisting chronically homeless people. This study compared housing, clinical, and service use outcomes of participants with high levels of substance use at time of housing entry and those who reported no substance use. Methods:Participants in the outcome evaluation of the 11-site Collaborative Initiative on Chronic Homelessness (N=756), who were housed within 12 months of program entry and received an assessment at time of housing and at least one follow-up (N=694, 92%), were classified as either high-frequency substance users (>15 days of using alcohol or >15 days of using marijuana or any other illicit drugs in the past 30 days; N=120, 16%) or abstainers (no days of use; N=290, 38%) on entry into supported community housing. An intermediate group reporting from one to 15 days of use (N=284, 38%) was excluded from the analysis. Mixed-model multivariate regres...
Thermodynamic stability and phases of general spinning branes

We determine the thermodynamic stability conditions for near-extreme rotating D3, M5, and M2-branes with multiple angular momenta. Critical exponents near the boundary of stability are discussed and compared with a naive field theory model. From a partially numerical computation we conclude that outside the boundary of stability, the angular momentum density tends to become spatially inhomogeneous. Periodic euclidean spinning brane solutions have been studied as models of QCD. We explain how supersymmetry is restored in the world-volume field theory in a limit where spin becomes large compared to total energy. We discuss the hierarchy of energy scales that develops as this limit is approached.
Joint wavelet-based coding and packetization for video transport over packet-switched networks

In recent years, wavelet theory applied to image, and audio and video compression has been extensively studied. However, only gaining compression ratio without considering the underlying networking systems is unrealistic, especially for multimedia applications over networks. In this paper, we present an integrated approach, which attempts to preserve the advantages of wavelet-based image coding scheme and to provide robustness to a certain extent for lost packets over packet-switched networks. Two different packetization schemes, called the intrablock-oriented (IAB) and interblock-oriented (IRB) schemes, in conjunction with wavelet-based coding, are presented. Our approach is evaluated under two different packet loss models with various packet loss probabilities through simulations which are driven by real video sequences.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Inhomogeneous steady states of diffusion-limited coalescence, A + A ⇌ A

Abstract We study the steady state of diffusion-limited coalescence, A + A ⇌ A , in the presence of a trap and with a background drift. In one dimension this model can be analyzed exactly through the method of inter-particle distribution functions (IPDF). Because of the irreversible trap the steady state of the system is a non-equilibrium state. An interesting phase transition, controlled by the drift away from the trap, takes place: from a non-trivial steady state, when the drift is weak, to a trivial steady state (the vacuum), as the drift increases beyond some critical point. Surprisingly, regardless of the drift strength, the computed IPDF resembles that of a homogeneous equilibrium system, without the trap. We suggest that this is due to “shielding”: the particle nearest to the trap shields the remaining particles from the effects of the trap. Finally, we compare the exact solution to that of a reaction-diffusion equation, and we determine the optimal values of the appropriate rate coefficients.
Asymmetric ketone reduction by a hyperthermophilic alcohol dehydrogenase. The substrate specificity, enantioselectivity and tolerance of organic solvents

In an effort to search for effective biocatalysts for asymmetric ketone reduction, the substrate specificity and enantioselectivity of an alcohol dehydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus have been evaluated. This hyperthermophilic alcohol dehydrogenase catalyzes the reduction of various ketones including aryl ketones, α- and β-ketoesters. Interestingly, aryl ketones, phenyl-substituted α- and β-ketoesters were reduced to the corresponding chiral alcohols in an enantiomerically pure form, while the substrates lacking phenyl groups were reduced with a moderate enantioselectivity. It thus suggests that a phenyl group next to the carbonyl group could be very helpful for achieving an excellent enantioselectivity, and this could provide valuable guidance for the future application of this useful enzyme through rational substrate engineering. The reaction temperature increased the enzyme activity, but exerted no effect on the enantioselectivity. This alcohol dehydrogenase also showed a high tolerance of organic solvents such as dimethyl sulfoxide, iso-propanol, methyl tert-butyl ether, and hexane, a particularly important and useful feature for the reduction of ketones with a low solubility in aqueous buffers.
Positron production by pulsars.

Calculations based on two specific pulsar models show that in either case the 511 keV gamma-ray line from the galactic center can be explained as the as the result of the annihilation of positrons produced by pulsars.
Restoring habitat permeability to roaded landscapes with isometrically-scaled wildlife crossings

Abstract Globally, human activities impact from one-third to one-half of the earth’s land surface; a major component of development involves the construction of roads. In the US and Europe, road networks fragment normal animal movement patterns, reduce landscape permeability, and increase wildlife-vehicle collisions, often with serious wildlife population and human health consequences. Critically, the placement of wildlife crossing structures to restore landscape connectivity and reduce the number of wildlife-vehicle collisions has been a hit-or-miss proposition with little ecological underpinning, however recent important developments in allometric scaling laws can be used to guide their placement. In this paper, we used cluster analysis to develop domains of scale for mammalian species groups having similar vagility and developed metrics that reflect realistic species movement dynamics. We identified six home range area domains; three quarters of 102 species clustered in the three smallest domains. We used HR 0.5 to represent a daily movement metric; when individual species movements were plotted against road mile markers, 71.2% of 72 species found in North America were included at distances of ⩽1 mi. The placement of wildlife crossings based on the HR 0.5 metric, along with appropriate auxiliary mitigation, will re-establish landscape permeability by facilitating wildlife movement across the roaded landscape and significantly improve road safety by reducing wildlife vehicle collisions.
AN UPDATED LOOK AT BINARY CHARACTERISTICS OF MASSIVE STARS IN THE CYGNUS OB2 ASSOCIATION

This work provides a statistical analysis of the massive star binary characteristics in the Cygnus OB2 association using radial velocity information of 114 B3-O5 primary stars and orbital properties for the 24 known binaries. We compare these data to a series of Monte Carlo simulations to infer the intrinsic binary fraction and distributions of mass ratios, periods, and eccentricities. We model the distribution of mass ratio, log-period, and eccentricity as power laws and find best-fitting indices of α = 0.1 ± 0.5, β = 0.2 ± 0.4, and γ = –0.6 ± 0.3, respectively. These distributions indicate a preference for massive companions, short periods, and low eccentricities. Our analysis indicates that the binary fraction of the cluster is 44% ± 8% if all binary systems are (artificially) assumed to have P < 1000 days; if the power-law period distribution is extrapolated to 104 years, then a plausible upper limit for bound systems, the binary fraction is ~90% ± 10%. Of these binary (or higher order) systems, ~45% will have companions close enough to interact during pre- or post-main-sequence evolution (semi-major axis 4.7 AU). The period distribution for P < 26 days is not well reproduced by any single power law owing to an excess of systems with periods around 3-5 days (0.08-0.31 AU) and a relative shortage of systems with periods around 7-14 days (0.14-0.62 AU). We explore the idea that these longer-period systems evolved to produce the observed excess of short-period systems. The best-fitting binary parameters imply that secondaries generate, on average, ~16% of the V-band light in young massive populations. This means that photometrically based distance measurements for young massive clusters and associations will be systematically low by ~8% (0.16 mag in the distance modulus) if the luminous contributions of unresolved secondaries are not taken into account.
A Stochastic Geometry Analysis of Inter-Cell Interference Coordination and Intra-Cell Diversity

Inter-cell interference coordination (ICIC) and intra-cell diversity (ICD) play important roles in improving cellular downlink coverage. By modeling cellular base stations (BSs) as a homogeneous Poisson point process (PPP), this paper provides explicit finite-integral expressions for the coverage probability with ICIC and ICD, taking into account the temporal/spectral correlation of the signal and interference. In addition, we show that, in the high-reliability regime, where the user outage probability goes to zero, ICIC and ICD affect the network coverage in drastically different ways: ICD can provide order gain, whereas ICIC only offers linear gain. In the high-spectral efficiency regime where the SIR threshold goes to infinity, the order difference in the coverage probability does not exist; however, a linear difference makes ICIC a better scheme than ICD for realistic path loss exponents. Consequently, depending on the SIR requirements, different combinations of ICIC and ICD optimize the coverage probability.
Chemical control of phospholipid distribution across bilayer membranes

Most biological membranes possess an asymmetric transbilayer distribution of phospholipids. Endogenous enzymes expend energy to maintain the arrangement by promoting the rate of phospholipid translocation, or flip-flop. Researchers have discovered ways to modify this distribution through the use of chemicals. This review presents a critical analysis of the phospholipid asymmetry data in the literature followed by a brief overview of the maintenance and physiological consequences of phospholipid asymmetry, and finishes with a list of chemical ways to alter phospholipid distribution by enhancement of flip-flop.
Anyon statistics and the Witten index

Abstract Using the theory of supersymmetric anyons, I extend the definition of the Witten index to 2+1 dimensions so as to accommodate the existence of anyon spin and statistics. I then demonstrate that, although in general the index receives irrational and complex contributions from anyonic states, the overall index is always integral, and I consider some of the implications and interpretations of this result.
The Environmental Impacts of Genetically Modified Plants: Challenges to Decision Making

A crucial controversy surrounding genetically modified plants (GMPs) is whether the commercialization of these plants should be delayed because of its potential environmental impacts. GMPs are exotic species introduced into open complex ecosystems of which we have limited understanding. Because they are released widely into the environment, they may have important scale and externality issues. In addition, the possibility of irreversible ecosystem disruptions is present (Gollier, Jullien, and Triech). This possibility exists in part because, despite the precision suggested by words such as "bioengineered," there can be unpredictable and novel effects of gene mixing (NRC 2002). Also, some risk management strategies for reducing environmental risks rely on uncertain compliance by farmers. Little is known about these environmental impacts (Ervin et al. 2001, Ervin et al. 2003, Wolfenbarger and Phifer). This situation raises challenges for decision making with respect to the release and commercialization of GMPs. For many crops, there is little consensus on whether to: (a) take action and release the product and mitigate any potential or emerging negative consequences, or (b) delay any action until there is more certainty about potential outcomes (Lemons, Shrader-Frechette, and Cranor). Selection of which action to take inherently implies answering two fundamental and interrelated questions: "What is an acceptable risk?" and "How do we manage uncertain risks?" Because of a lack of consensus on these questions, the biotechnology debate revolves around the adequacy of the management institutions and processes by which decisions are made.
Quadratic programming based data assimilation with passive drifting sensors for shallow water flows

We present a method for assimilating Lagrangian sensor measurement data into a shallow water equation model. The underlying estimation problem (in which the dynamics of the system are represented by a system of partial differential equations) relies on the formulation of a minimisation of an error functional, which represents the mismatch between the estimate and the measurements. The corresponding so-called variational data assimilation problem is formulated as a quadratic programming problem with linear constraints. For the hydrodynamics application of interest, data is obtained from drifting sensors that gather position and velocity. The data assimilation method refines the estimate of the initial conditions of the hydrodynamic system. The method is implemented using a new sensor network hardware platform for gathering flow information from a river, which is presented in this article for the first time. Validation of the results is performed by comparing them to an estimate derived from an independent ...
Why Are Earnings Kinky? An Examination of the Earnings Management Explanation

Prior research has documented a “kink” in the earnings distribution: too few firms report small losses, too many firms report small profits. We investigate whether boosting of discretionary accruals to report a small profit is a reasonable explanation for this “kink.” Overall, we are unable to confirm that boosting of discretionary accruals is the key driver of the kink. We caution the use of the ratio of small profit firms to small loss firms as a measure of earnings management. We investigate and discuss a number of alternative explanations for the kink.
PV Reliability Development Lessons From JPL's Flat Plate Solar Array Project

Key reliability and engineering lessons that were learned from the 20-year history of the Jet Propulsion Laboratory's Flat-Plate Solar Array Project and thin-film module reliability research activities are presented and analyzed. Particular emphasis is placed on lessons applicable to evolving new module technologies and the organizations involved with these technologies. The user-specific demand for reliability is a strong function of the application, its location, and its expected duration. Lessons relative to effective means of specifying reliability are described, and commonly used test requirements are assessed from the standpoint of which are the most troublesome to pass, and which correlate best with field experience. Module design lessons are also summarized, including the significance of the most frequently encountered failure mechanisms and the role of encapsulant and cell reliability in determining module reliability. Lessons pertaining to research, design, and test approaches include the historical role and usefulness of qualification tests and field tests.
Radiation and scattering from structures involving finite-size dielectric regions

A full-wave approach to calculating the scattered fields produced by structures that involve finite-size dielectric regions is presented. The dielectric is approximated by a thin-wall structure, and the electric field boundary conditions are applied through the use of appropriate surface impedances. Rooftop basis functions are employed in the moment method approach. The matrix elements are calculated, depending upon the distance between the source and field locations, through a scheme that employs Taylor series expansions and point source approximations. The technique is applied to scattering from dielectric cubes and composite dielectric-conductor structures, and to radiation from microstrip structures. Numerical convergence and agreement with the literature are demonstrated. >
Deep MMT Transit Survey of the Open Cluster M37 I: Observations and Cluster Parameters

We have conducted a deep ( -->15 r 23), 20 night survey for transiting planets in the intermediate-age open cluster M37 (NGC 2099) using the Megacam wide-field mosaic CCD camera on the 6.5 m MMT. In this paper we describe the observations and data reduction procedures for the survey and analyze the stellar content and dynamical state of the cluster. By combining high-resolution spectroscopy with existing -->BVICKs and new gri color-magnitude diagrams, we determine the fundamental cluster parameters: -->t = 485 ± 28 Myr without overshooting ( -->t = 550 ± 30 Myr with overshooting), -->E(B − V) = 0.227 ± 0.038, -->(m − M)V = 11.57 ± 0.13, and -->[ M/H ] = + 0.045 ± 0.044, which are in good agreement with, although more precise than, previous measurements. We determine the mass function down to 0.3 M☉ and use this to estimate the total cluster mass of -->3640 ± 170 M☉.
Simulating weak lensing by large scale structure

Author(s): Vale, Chris; White, Martin | Abstract: We model weak gravitational lensing of light by large-scale structure using ray tracing through N-body simulations. The method is described with particular attention paid to numerical convergence. We investigate some of the key approximations in the multi-plane ray tracing algorithm. Our simulated shear and convergence maps are used to explore how well standard assumptions about weak lensing hold, especially near large peaks in the lensing signal.