cssi/SciSciGPT-SciSciNet huggingface dataset:
The Symmetry, Color, and Morphology of Galaxies

The structural symmetry of forty-three face-on galaxy images in the R(650 nm) and J(450 nm) bands are measured to determine the usefulness of symmetry as a morphological parameter. Each galaxy image is rotated by 180° and subtracted from the original to obtain a quantitative value for its structural symmetry. The symmetry numbers computed for the sample are then compared with RC3 morphological types, color & absolute blue magnitudes. A strong correlation between color and symmetry is found, and the RC3 Hubble sequence is found to be one of increasing asymmetry. The use of symmetry as a morphological parameter, and the possible causes of the asymmetries are discussed.
Spatial Complementarity of Forests and Farms: Accounting for Ecosystem Services

Our article considers the economic contributions of forest ecosystem services, using a case study from Flores, Indonesia, in which forest protection in upstream watersheds stabilize soil and hydrological flows in downstream farms. We focus on the demand for a weak complement to the ecosystem services—farm labor—and account for spatial dependence due to economic interactions, ecosystem processes, and data integration. The estimated models have theoretically expected properties across eight different specifications. We find strong evidence that forest ecosystem services provide economically substantive benefits to local people and that these services would be substantially undervalued if spatial dependence is ignored. Forests provide an array of ecosystem services by sequestering carbon, maintaining habitat and biodiversity, stabilizing hydrological flows, mitigating soil erosion, and improving microclimates. Deforestation and forest degradation can irreversibly and substantively impair these ecosystem functions. This raises the question of why society and governments would allow rapid or excessive deforestation. One reason is the failure to consider the full range of goods and services provided by the forests, particularly any latent and complex ecosystem services (Dasgupta). The economic contributions of forest ecosystem services are not well understood and rarely quantified. This article illustrates a method for estimating the value of watershed services from protected tropical forests in Flores, Indonesia. Specifically, we respond to three challenges posed in the literature. First, valuation studies have typically overlooked livelihood values of natural resources in developing countries, focusing largely on amenity values in developed countries (Deacon et al., Dasgupta). Second, a detailed consideration of the spatial aspects of ecosystems and ecological processes, such
Estimating Failure Propagation In Models Of Cascading Blackouts

We compare and test statistical estimates of failure propagation in data from versions of a probabilistic model of loading-dependent cascading failure and a power system blackout model of cascading transmission line overloads. The comparisons suggest mechanisms affecting failure propagation and are an initial step toward monitoring failure propagation from practical system data. Approximations to the probabilistic model describe the forms of probability distribution of cascade sizes.
Relaxation Techniques for Three-Dimensional Transonic Flow about Wings

A relaxation procedure has been developed to treat the three-dimensional, transonic small perturbation equations about finite lifting wings. A combination of two schemes is employed. For flow forward of the wing trailing edge the equations are written in terms of a velocity potential in order to minimize computer algebra and storage. For the remaining flow field the equations are written in terms of the velocity components in order to simplify the enforcement of the Kutta condition. Difference equations and relaxation procedures are described for both schemes. The computational method automatically captures the imbedded shock wave in the three-dimensional flow field. Computed results are given and compared to experiment and other inviscid methods.
Low-rank estimation of higher order statistics

Low-rank estimators for higher order statistics are considered in this paper. The bias-variance tradeoff is analyzed for low-rank estimators of higher order statistics using a tensor product formulation for the moments and cumulants. In general, the low-rank estimators have a larger bias and smaller variance than the corresponding full-rank estimator, and the mean-squared error can be significantly smaller. This makes the low-rank estimators extremely useful for signal processing algorithms based on sample estimates of the higher order statistics. The low-rank estimators also offer considerable reductions in the computational complexity of such algorithms. The design of subspaces to optimize the tradeoffs between bias, variance, and computation is discussed, and a noisy input, noisy output system identification problem is used to illustrate the results.
Haptic rendering of surface-to-surface sculpted model interaction

Previous work in haptics surface tracing for virtual prototyping and surface design applications has used a point model for virtual finger-surface interaction. We extend this tracing method for surface-to-surface interactions. A straightforward extension of the point-surface formulation to surface-surface can yield extraneous, undesirable solutions, although we rework the formulation to yield more satisfactory solutions. Additionally, we derive an alternative novel velocity formulation for use in a surface-surface tracing paradigm that exhibits additional stability beyond the Newton methods. Both methods require evaluating the surface point and first and second surface partial derivatives for both surfaces, an efficient kilohertz rate computation. These methods are integrated into a three step tracking process that uses a global minimum distance method, the local Newton formulation, and the new velocity formulation.
Millimeter-wave mode conversion by a solid-state magnetoplasma

Solid-state magnetoplasma devices have been recently proposed as phase-shifters, isolators, filters, and circulators for use at millimeter and sub-millimeter wavelengths. We herewith report observations of phenomena indicating that magnetoplasmas can also be utilized to efficiently transduce millimeter and submillimeter energy from one waveguide mode to another present microwave devices which accomplish this function are mechanical in nature and are thus subject to wavelength limitations imposed by dimensional tolerances. Besides circumventing such limitations, magnetoplasma mode-conversion devices have the additional advantage of being magnetically controllable. In the present paper, we consider one-port conversion from the circular TE/spl circle /sub01/ mode to the circular TM/spl circle over sub 01/ mode. The basic principle is, however, also applicable to two-port conversion and to several other choices of waveguide geometry and mode-pair.
Bone marrow fat is increased in chronic kidney disease by magnetic resonance spectroscopy.

In aging, the bone marrow fills with fat and this may lead to higher fracture risk. We show that a bone marrow fat measurement by magnetic resonance spectroscopy (MRS), a newer technique not previously studied in chronic kidney disease (CKD), is useful and reproducible. CKD patients have significantly higher bone marrow fat than healthy adults. Renal osteodystrophy leads to increased morbidity and mortality in patients with CKD. Traditional bone biopsy histomorphometry is used to study abnormalities in CKD, but the bone marrow, the source of osteoblasts, has not been well characterized in patients with CKD. To determine the repeatability of bone marrow fat fraction assessment by MRS and water-fat imaging (WFI) at four sites in patients with CKD, testing was performed to determine the coefficients of reproducibility and intraclass coefficients (ICCs). We further determined if this noninvasive technique could be used to determine if there are differences in the percent bone marrow fat in patients with CKD compared to matched controls using paired t tests. The mean age of subjects with CKD was 59.8 ± 7.2 years, and the mean eGFR was 24 ± 8 ml/min. MRS showed good reproducibility at all sites in subjects with CKD and controls, with a coefficient of reproducibilities ranging from 2.4 to 13 %. MRS and WFI assessment of bone marrow fat showed moderate to strong agreement (ICC 0.6–0.7) at the lumbar spine, with poorer agreement at the iliac crest and no agreement at the tibia. The mean percent bone marrow fat at L2–L4 was 13.8 % (95 % CI 8.3–19.7) higher in CKD versus controls (p < 0.05). MRS is a useful and reproducible technique to study bone marrow fat in CKD. Patients with CKD have significantly higher bone marrow fat than healthy adults; the relationship with bone changes requires further analyses.
A Preliminary Appraisal of the Cornucopia Concept

Initial feasibility studies suggest that the utility of certain storable rocket propellants can be extended to include life support and other essential services in the space environment, thereby improving the habitability and over-all performance of manned systems. Two liquid combinations are considered: hydrazine/hydrogen peroxide and hydrazine/nitrogen tetroxide. Both are good propellants, and their oxidizer-rich combustion in a gas generator theoretically yields potable water, a two-gas atmosphere of controllable composition, and energy for power generation and/or thermal management. The basic thermochemical relationships are presented from which performance in specific areas is derived. Problems of contamination , safety, and reliability are discussed, and possible applications to manned probes, space stations, extravehicular operations, planetary bases, biosatellites, and high-altitude aircraft are explored. The concept is applied in some detail to two hypothetical missions, and its over-all effectiveness is compared with that of more conventional approaches.
On measured behavior of the ARPA network

The purpose of this paper is to present and evaluate the results of recent measurements of the ARPA network. We first discuss the tools available for performing these measurements. We then describe the results of a particular experiment, which consisted of data collection over a continuous seven day period. The measured quantities included input traffic, line traffic, and message delays. This data is discussed in terms of network behavior and compared to analytic models. Lastly, we consider some implications and tradeoffs derived from these measurements which provide insight regarding the performance of computer networks.
Symplectic Multiple Flag Varieties of Finite Type

Abstract We classify products of partial flag varieties of the symplectic group for which the diagonal action has finitely many orbits.
Path-independent load balancing with unreliable machines

We consider algorithms for load balancing on unreliable machines. The objective is to optimize the two criteria of minimizing the makespan and minimizing job reassignments in response to machine failures. We assume that the set of jobs is known in advance but that the pattern of machine failures is unpredictable. Motivated by the requirements of BGP routing, we consider path-independent algorithms, with the property that the job assignment is completely determined by the subset of available machines and not the previous history of the assignments. We examine first the question of performance measurement of path-independent load-balancing algorithms, giving the measure of makespan and the normalized measure of reassignments cost. We then describe two classes of algorithms for optimizing these measures against an oblivious adversary for identical machines. The first, based on independent random assignments, gives expected reassignment costs within a factor of 2 of optimal and gives a makespan within a factor of O (log m/log log m) of optimal with high probability, for unknown job sizes. The second, in which jobs are first grouped into bins and at most one bin is assigned to each machine, gives constant-factor ratios on both reassignment cost and makespan, for known job sizes. Several open problems are discussed.
Accurate Spectral Modeling for Infrared Radiation

Direct line-by-line integration and quasi-random band model techniques are employed to calculate the spectral transmittance and total band absorptance of 4.7 micron CO, 4.3 micron CO2, 15 micron CO2, and 5.35 micron NO bands. Results are obtained for different pressures, temperatures, and path lengths. These are compared with available theoretical and experimental investigations. For each gas, extensive tabulations of results are presented for comparative purposes. In almost all cases, line-by-line results are found to be in excellent agreement with the experimental values. The range of validity of other models and correlations are discussed.
Evaluation of the Cytocentrifuge Gram Stain as a Screening Test for Bacteriuria in Specimens From Specific Patient Populations

To assess the usefulness of the cytocentrifuge Gram stain as a urine screening test in the clinical microbiology laboratory for the elimination of culture for screen-negative specimens, we compared the results of the cytocentrifuge Gram stain to the results of culture for 1,171 urine specimens. The data were analyzed separately for specimens from males (inpatients) and females (inpatients and outpatients), as well as for catheterized and voided specimens. Overall, the cytocentrifuge Gram stain had excellent negative predictive value (97.7%) and sensitivity (92.3%) at a culture threshold of 10(5) colony-forming units per milliliter or more. The negative predictive value and sensitivity decreased at lower culture thresholds in all populations. The negative predictive value decreased most markedly for female outpatients. Because of low positive predictive value and specificity, this test is not reliable as a sole indicator for presumptive therapy in many cases with positive results. If its limitations are recognized, the cytocentrifuge Gram stain is a useful screening test for the rapid exclusion of bacteriuria.
Derivation of Tsallis statistics from dynamical equations for a granular gas

In this paper we present the explicit calculation of the velocity probability distribution function P(v) for a model system of granular gas within the framework of Tsallis non-extensive statistical mechanics, using the stochastic approach by Beck (2001 Phys. Rev. Lett. 87 180601), further generalized by Sattin and Salasnich (2002 Phys. Rev. E 65 035106(R)). The calculation is self-consistent in that the form of P(v) is not given as an ansatz but is shown to necessarily arise from the known microscopic dynamics of the system.
A compressed sensing wire-tap channel

A multiplicative Gaussian wire-tap channel inspired by compressed sensing is studied. Lower and upper bounds on the secrecy capacity are derived, and shown to be relatively tight in the large system limit for a large class of compressed sensing matrices. Surprisingly, it is shown that the secrecy capacity of this channel is nearly equal to the capacity without any secrecy constraint provided that the channel of the eavesdropper is strictly worse than the channel of the intended receiver. In other words, the eavesdropper can see almost everything and yet learn almost nothing. This behavior, which contrasts sharply with that of many commonly studied wiretap channels, is made possible by the fact that a small number of linear projections can make a crucial difference in the ability to estimate sparse vectors.
The facet ideal of a simplicial complex

To a simplicial complex, we associate a square-free monomial ideal in the polynomial ring generated by its vertex set over a field. We study algebraic properties of this ideal via combinatorial properties of the simplicial complex. By generalizing the notion of a tree from graphs to simplicial complexes, we show that ideals associated to trees satisfy sliding depth condition, and therefore have normal and Cohen-Macaulay Rees rings. We also discuss connections with the theory of Stanley-Reisner rings.
Elastodynamic analysis and design of an inchworm robotic insect

The paper presents an inchworm robotic insect that is capable of motion over smooth terrain. The structure is lightly-damped and consists of a unimorph piezoelectric actuator (THUNDER) that acts as both structural member and source of motion and two custom-designed limbs that are attached to the body by means of adjustable clamps. The limbs can either roll or drag on the ground when an appropriate resonance is excited. The approach is called elastodynamic locomotion. A cycle of this `falling-ahead' unidirectional motion is composed of two segments: a shorter one when the front leg is rolling on the ground surface and transports the structure ahead while the rear leg drags on the ground, and a longer one, when the legs interchange their functions. The mathematical model assumes the legs are compliant. The geometry of deformation was utilized to find a configuration that is capable of maximizing the horizontal displacement of the robot. An actual inchworm design produced a motion that confirmed the theoretical predictions. A lumped-parameter dynamic model was formulated that allowed evaluation of the ground reaction forces and the velocity of the robot by using data of the geometric model and solving the inverse dynamics problem.
Effective-medium theory of electronic states in structurally disordered metals: Application to liquid Cu

We consider the application of the effective-medium approximation (EMA) to the muffin-tin model of a liquid metal. The spherical symmetry of the average liquid is used to reduce the momentum ($\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}$)-dependent self-consistency requirements of the theory to a form in which they involve one-dimensional rather than three-dimensional integrations. We also show that, within the EMA, a closed expression for the integrated density of states can be derived, and that this expression provides a useful check on the convergence of the self-consistent equations. The theory is applied to liquid Cu. The self-consistent equations converge without difficulty and the resulting electronic spectrum is in substantial agreement with recent photoemission data. Our results are compared with an alternate approach to the muffin-tin EMA suggested by Asano and Yonezawa. The two approaches yield similar densities of states but markedly different behavior for the special functions.
“Bicyclobenzodiazepinones” from 3-oxo-1,2-diazetidinium hydroxide, inner salts

Abstract 1,3-Dipolar cycloaddition of benzyne with 3-oxo-l,2-diazetidinium hydroxide, inner salts leads to tricyclic adducts which have been termed “bicyclobenzodiazepinones” because of their structural relationship to 1,4-benzodiazepinones. In analogous fashion, cycloaddition of benzyne with 3-oxopyrazolidinium hydroxide, inner salts, leads to homologous tricyclic adducts. Efforts to convert these readily accessible condensed aza-β-lactams and aza-γ-lactams to benzodiazepinones and benzodiazocinones are described. Several novel ring cleavage reactions leading from the above “bicyclobenzodiazepinones” to indazoles are reported.
Vortex perturbation dynamics

An initial value approach is used to examine the dynamics of perturbations introduced into a vortex under strain. Both the basic vortex considered and the perturbations are taken as fully three-dimensional. An explicit solution for the time evolution of the vorticity perturbations is given for arbitrary initial vorticity. Analytical solutions for the resulting velocity components are found when the initial vorticity is assumed to be localized. For more general initial vorticity distributions, the velocity components are determined numerically. It is found that the variation in the radial direction of the initial vorticity disturbance is the most important factor influencing the qualitative behavior of the solutions. Transient growth in the magnitude of the velocity components is found to be directly attributable to the compactness of the initial vorticity.
An ultrahigh-speed digitizer for the Harvard College Observatory astronomical plates

A machine capable of digitizing two 8 inch by 10 inch (203 mm by 254 mm) glass astrophotographic plates or a single 14 inch by 17 inch (356 mm by 432 mm) plate at a resolution of 11 μm per pixel or 2309 dots per inch (dpi) in 92 seconds is described. The purpose of the machine is to digitize the ~500,000 plate collection of the Harvard College Observatory in a five-year time frame. The digitization must meet the requirements for scientific work in astrometry, photometry, and archival preservation of the plates. This paper describes the requirements for and the design of the subsystems of the machine that was developed specifically for this task.
On the maximum number of edges in a hypergraph with a unique perfect matching

In this note, we determine the maximum number of edges of a k -uniform hypergraph, k ? 3 , with a unique perfect matching. This settles a conjecture proposed by Snevily.
Institutional incentives and earnings quality: The influence of government ownership in China

Abstract We examine the effect of government ownership and its associated institutional incentives on firms’ earnings quality using a sample of Chinese firms during the transitional economy between 1998 and 2005 when state-owned and non-state-owned firms were traded in the stock exchanges. We find that, in China, state-owned firms exhibit a lower earnings quality property than non-state-owned firms. Particularly, state-owned firms have more earnings smoothing, more frequently managed earnings toward target, less frequent timely recognition of losses, and less value relevance, relative to non-state-owned firms. We also find that state-owned firms have significantly higher discretionary current accruals than non-state-owned firms. We conclude that the Chinese government, through its controlling ownership of state-owned firms, creates incentives and regulatory backing for self-serving purposes that negatively influence these listed firms’ financial reporting.
The Starburst-Interstellar Medium Interaction in NGC 1569. II. Small-Scale Examination of Nebular Emission, H II Region Size Distribution, and H II Region Luminosity Function

As the nearest dramatic example of a poststarburst galaxy driving a galactic wind, NGC 1569 is an ideal test environment to understand the impact of "feedback" from massive star lives and deaths on the surrounding interstellar medium. We present Hubble Space Telescope Wide Field Planetary Camera 2 narrowband imagery of NGC 1569 in an attempt to understand the underlying ionizing emission mechanisms on a 3 pc scale and to generate a H II region size distribution and luminosity function. We use [O III]/Hβ and [S II]/Hα ratio maps to find that nonphotoionizing mechanisms (e.g., shocks) are responsible for 10% ± 3% of the Hα emission, 2.5-3 times larger than results from similar galaxies. Note that our method of determining this result is different from these past results, a point that we discuss further in this paper. The area of the nonphotoionized region is 10%-23% of the total. Our results for NGC 1569 indicate that these nonphotoionized areas do not lie in low surface brightness regions exclusively. A comparison with multiwavelength point-source catalogs of NGC 1569 indicates that the dominant nonphotoionizing mechanisms are shocks from supernovae or winds from massive stars. To explain this large percentage of nonphotoionized emission, we suggest that NGC 1569 is, indeed, in a poststarburst phase, as previous authors have claimed. We also derive slopes for the H II region luminosity function (-1.00 ± 0.08) and size distribution (-3.02 ± 0.27). The luminosity slope, although shallow, is similar to previous work on this galaxy and other irregular galaxies. The size distribution slope is shallower than previous slopes found for irregular galaxies, but our slope value fits into their confidence intervals, and vice versa. Within 4 pc of the 10-20 Myr old super star clusters A1, A2, and B, no bright H II regions exist to a luminosity limit of 2.95 × 1036 ergs s-1, suggesting that the winds and shocks have effectively terminated star formation in this small cavity. In the three annular regions around the super star clusters, both the H II region luminosity function and H II region size distribution are consistent with respect to one another and the galaxy as a whole. The H II region surface densities within the annuli remain the same as the annuli are moved away from the super star clusters. These results indicate that feedback effects in NGC 1569 are confined to the immediate vicinity of the most recent massive star formation event on scales of ~1 pc.
MAPPING DIRECTLY IMAGED GIANT EXOPLANETS

With the increasing number of directly imaged giant exoplanets, the current atmosphere models are often not capable of fully explaining the spectra and luminosity of the sources. A particularly challenging component of the atmosphere models is the formation and properties of condensate cloud layers, which fundamentally impact the energetics, opacity, and evolution of the planets. Here we present a suite of techniques that can be used to estimate the level of rotational modulations these planets may show. We propose that the time-resolved observations of such periodic photometric and spectroscopic variations of extrasolar planets due to their rotation can be used as a powerful tool to probe the heterogeneity of their optical surfaces. In this paper, we develop simulations to explore the capabilities of current and next-generation ground- and space-based instruments for this technique. We address and discuss the following questions: (1) what planet properties can be deduced from the light curve and/or spectra, and in particular can we determine rotation periods, spot coverage, spot colors, and spot spectra?; (2) what is the optimal configuration of instrument/wavelength/temporal sampling required for these measurements?; and (3) can principal component analysis be used to invert the light curve and deduce the surface map of the planet? Our simulations describe the expected spectral differences between homogeneous (clear or cloudy) and patchy atmospheres, outline the significance of the dominant absorption features of H2O, CH4, and CO, and provide a method to distinguish these two types of atmospheres. Assuming surfaces with and without clouds for most currently imaged planets the current models predict the largest variations in the J band. Simulated photometry from current and future instruments is used to estimate the level of detectable photometric variations. We conclude that future instruments will be able to recover not only the rotation periods, cloud cover, cloud colors, and spectra but even cloud evolution. We also show that a longitudinal map of the planet's atmosphere can be deduced from its disk-integrated light curves.
Threshold estimation based on a p-value framework in dose-response and regression settings

We use p-values to identify the threshold level at which a regression function leaves its baseline value, a problem motivated by applications in toxicological and pharmacological dose-response studies and environmental statistics. We study the problem in two sampling settings: one where multiple responses can be obtained at a number of different covariate levels, and the other the standard regression setting involving limited number of response values at each covariate. Our procedure involves testing the hypothesis that the regression function is at its baseline at each covariate value and then computing the potentially approximate p-value of the test. An estimate of the threshold is obtained by fitting a piecewise constant function with a single jump discontinuity, known as a stump, to these observed p-values, as they behave in markedly different ways on the two sides of the threshold. The estimate is shown to be consistent and its finite sample properties are studied through simulations. Our approach is computationally simple and extends to the estimation of the baseline value of the regression function, heteroscedastic errors and to time series. It is illustrated on some real data applications.
Selecting Probabilistic Approaches for Reliability-Based Design Optimization

During the past decade, numerous endeavors have been made to develop effective reliability-based design optimization (RBDO) methods. Because the evaluation of probabilistic constraints defined in the RBDO formulation is the most difficult part to deal with, a number of different probabilistic design approaches have been proposed to evaluate probabilistic constraints in RBDO. In the first approach, statistical moments are approximated to evaluate the probabilistic constraint. Thus, this is referred to as the approximate moment approach (AMA). The second approach, called the reliability index approach (RIA), describes the probabilistic constraint as a reliability index. Last, the performance measure approach (PMA) was proposed by converting the probability measure to a performance measure. A guide for selecting an appropriate method in RBDO is provided by comparing probabilistic design approaches for RBDO from the perspective of various numerical considerations. It has been found in the literature that PMA is more efficient and stable than RIA in the RBDO process. It is found that PMA is accurate enough and stable at an allowable efficiency, whereas AMA has some difficulties in RBDO process such as a second-order design sensitivity required for design optimization, an inaccuracy to measure a probability of failure, and numerical instability due to its inaccuracy. Consequently, PMA has several major advantages over AMA, in terms of numerical accuracy, simplicity, and stability. Some numerical examples are shown to demonstrate several numerical observations on the three different RBDO approaches.
Kinetics and nitro-products of the gas-phase OH and NO3 radical-initiated reactions of naphthalene-d8, Fluoranthene-d10, and pyrene

The kinetics and nitroarene product yields of the gas-phase reactions of naphthalene-d 8 , fluoranthene-d 10 , and pyrene with OH radicals in the presence of NO x and in N 2 O 5 -No 3 -NO 2 -air mixtures have been investigated at 296±2 K and atmospheric pressure of air. Using a relative rate method, naphthalene-d 8 was shown to react in N 2 O 5 −NO 2 3−NO 2 −air mixtures a factor of 1.22±0.10 times faster than than did naphthalene, with the 1- and 2-nitronaphthalene-d 7 product yields being similar to those of 1- and 2-nitronaphthalene from naphthalene. From the measured PAH concentrations and the nitroarene product yields, formation yields of 2-, 7-, and 8-nitrofluoranthene-d 9 and 2- and 4-nitropyrene of 0.03, 0.01, 0.003, 0.005, and 0.0006, respectively, were determined from the OH radical-initiated reactions. Effective rate constants for the reactions of fluoranthene-d 10 and pyrene with N 2 O 5 in N 2 O 5 −NO 3 −NO 2 −air mixtures of ca. 1.8×10 −17 cm 3 molecule −1 s −1 and ca. 5.6×10 −17 cm 3 molecule −1 s -1 , respectively, were derived. Formation yields of 2-nitrofluororanthene-d 9 and 4-nitropyrene of ca. 0.24 and ca. 0.0006, respectively, were estimated for these reaction systems. 2-nitropyrene was also observed to be formed in these N 2 O 5 −NO 3 −NO 2 reactions, but was found to be a function of the NO 2 concentration and, therefore, would be a negligible product under ambient NO 2 concentrations. These product and kinetic data are consistent with ambient air measurements of the nitroarene concentrations
Observing Massive Galaxy Formation

A major goal of contemporary astrophysics is understanding the origin of the most massive galaxies in the universe, particularly nearby ellipticals and spirals. Theoretical models of galaxy formation have existed for many decades, although observational evidence at both low and high redshifts is only beginning to put constraints on different ideas. We briefly describe these observations and how they are revealing the methods by which galaxies form by contrasting and comparing fiducial rapid collapse and hierarchical formation model predictions. The available data show that cluster ellipticals must have rapidly formed at z > 2 , and that up to 50% of all massive galaxies at z ~ 2.5 are involved in major mergers. While the former is consistent with the monolithic collapse picture, we argue that hierarchical formation is the only model that can reproduce all the available observations.
Metabolic Tumor Profiling with pH, Oxygen, and Glucose Chemosensors on a Quantum Dot Scaffold

Acidity, hypoxia, and glucose levels characterize the tumor microenvironment rendering pH, pO2, and pGlucose, respectively, important indicators of tumor health. To this end, understanding how these parameters change can be a powerful tool for the development of novel and effective therapeutics. We have designed optical chemosensors that feature a quantum dot and an analyte-responsive dye. These noninvasive chemosensors permit pH, oxygen, and glucose to be monitored dynamically within the tumor microenvironment by using multiphoton imaging.
Encouraging accountability in research: a pilot assessment of training efforts.

Purpose. This pilot assessment describes institutional approaches to satisfying the NIH training requirement in the responsible conduct of research. Descriptive information from this review will be valuable for institutions and researchers who are developing or improving training programs. Methods. The authors reviewed materials submitted by a sample of grantee institutions in response to a request by the U.S. Department of Health and Human Services. Institutional and programmatic characteristics were summarized and described. Results. Institutions in the sample employed a diversity of approaches to satisfying the training grant requirement. Approaches varied both among and within institutions. Further, the number of training grants held at the institution had some impact on how the training grant requirement was met. Conclusion. This assessment is a valuable first step in describing institutional responses to the NIH training grant requirement. It indicates the need for further research on institutional ...
Saturn's rings, the Yarkovsky effects, and the Ring of Fire

The dimensions of Saturn's A and B rings may be determined by the seasonal Yarkovsky effect and the Yarkovsky-Schach effect; the two effects confine the rings between approximately 1.68 and approximately 2.23 Saturn radii, in reasonable agreement with the observed values of 1.525 and 2.267. The C ring may be sparsely populated because its particles are transients on their way to Saturn; the infall may create a luminous Ring of Fire around Saturn's equator. The ring system may be young: in the past heat flow from Saturn's interior much above its present value would not permit rings to exist.
Dissolved and colloidal trace elements in the Mississippi River delta outflow after Hurricanes Katrina and Rita

Abstract The Mississippi River delta outflow region is periodically disturbed by tropical weather systems including major hurricanes, which can terminate seasonal bottom water hypoxia and cause the resuspension of shelf bottom sediments which could result in the injection of trace elements into the water column. In the summer of 2005, Hurricanes Katrina and Rita passed over the Louisiana Shelf within a month of each other. Three weeks after Rita, we collected water samples in the Mississippi River delta outflow, examining the distributions of trace elements to study the effect of Hurricanes Katrina and Rita. We observed limited stratification on the shelf and bottom waters that were no longer hypoxic. This resulted, for instance, in bottom water dissolved Mn being lower than is typically observed during hypoxia, but with concentrations still compatible with Mn–O 2 trends previously reported. Interestingly, for no element were we able to identify an obvious effect of sediment resuspension on its distribution. In general, elemental distributions were compatible with previous observations in the Mississippi outflow system. Co and Re, which have not been reported for this system previously, showed behavior consistent with other systems: input for Co likely from desorption and conservative mixing for Re. For Cs, an element for which there is little information regarding its estuarine behavior, conservative mixing was also observed. Our filtration method, which allowed us to distinguish the dissolved (
Observations and simulations of the ionospheric and thermospheric response to the December 2006 geomagnetic storm : Initial phase

[1] We have investigated the thermospheric and ionospheric response to the 14–15 December 2006 geomagnetic storm using a Coupled Magnetosphere Ionosphere Thermosphere (CMIT) 2.0 model simulation. In this paper we focus on observations and simulations during the initial phase of the storm (about 8 h), when the shock was driving changes in geospace. The global ionospheric maps of total electron content (TEC), ionosonde data at four stations and Millstone Hill incoherent scatter radar (ISR) observations are compared with the corresponding simulation results from the CMIT model. The observations showed significant positive storm effects occurred in the Atlantic sector after the onset of this storm. The CMIT model is able to capture the temporal and spatial variations of the ionospheric storm effects seen in the GPS TEC observations, although the model slightly underestimates the daytime positive ionospheric storm in the South American sector. The simulations are also in agreement with the ionosonde and ISR ionospheric measurements. Term analysis of the ion continuity equation demonstrates that changes in the electric fields play a dominant role in generating the observed ionospheric positive storm effect in the American sector during the initial phase, although neutral winds and composition changes also contribute. The difference in the strength of the enhancements over North and South America can be explained by the slope of the topside electron density profiles in the two hemispheres. In the southern hemisphere electron densities decrease slowly with altitude, whereas the decrease is much more rapid in the northern (winter) hemisphere. The electric fields, therefore, cannot cause large increases in electron density by uplifting the plasma, so positive storm effects are small in the southern hemisphere compared with the northern hemisphere, even though the increase in hmF2 is greater in the southern hemisphere. Nighttime changes in electron density in other longitude sectors are small, because the topside electron densities also decrease slowly with altitude at night.
Balanced singular values for LQG/LTR design

Multivariate design methods based on robustness results for the linear-quadratic regulator or for the Kalman filter require selection of either state/control weighting matrices or process/measurement noise covariance matrices that yield loop return ratios satisfying user-specified design criteria. Such criteria include disturbance rejection, command following, closed-loop bandwidth and robustness to unstructured uncertainty. The standard method of achieving this first ‘balances’ the singular values of the return ratio of the design at either zero or infinite frequency. An algorithm is described in this paper for ‘balancing’ these singular values at arbitrary frequencies, providing additional design flexibility.
Three Years of ChaMPlane Northern Field WIYN Spectroscopy

We present initial results of WIYN spectroscopic observations of selected objects detected in the Chandra Multiwavelength Plane (ChaMPlane) Survey in fields toward the Galactic anticenter. ChaMPlane is designed to identify low-luminosity X-ray sources, both accretion-powered and stellar coronal, in the Galaxy. It also includes a wide-field optical imaging Survey conducted with the NOAO Mosaic cameras to identify optical counterparts, as well as Hα-selected objects in the ~5 times larger field. We report spectroscopic classifications for 1069 objects in Galactic anticenter (i.e., northern) fields, resulting in 612 type determinations. These include 5 new cataclysmic variables, 4 Be stars, 14 lithium-absorption stars, 182 stellar coronal sources (primarily dMe stars), and 30 new quasars. Bright optical counterparts of Chandra sources in this sample are most frequently dMe stars, whereas a majority of the faintest (R > 20.5 mag) spectroscopically classified Chandra source counterparts are quasars. The bulk of Hα-selected sources appears to be roughly evenly divided between dMe stars and M stars at all magnitudes.
The locus effect on inertia equity

Purpose – The paper attempts to answer “Will the shift from the locus of self to locus of others impact the magnitude of loss aversion?” and “Will different prices affect the self‐other asymmetry in choice?”.Design/methodology/approach – The design is a two (locus: self vs others) by two (anchoring price: $30 vs $90) between‐subjects’ factorial with both the locus of evaluation and the monthly service plan charges (anchoring prices) as the between‐subjects’ factors.Findings – The author finds that inertia equity is smaller when consumers evaluate peer customers than when they evaluate themselves to switch brands. It is also found that the locus effect is applicable to brands at various prices.Research limitations/implications – Further research should focus on the validations of the assumptions to support the empirical finding from the theoretical perspective.Practical implications – Price reductions should be made personally relevant to the consumer and price increases should be made relevant to other th...
Inequalities with determinants of perturbed positive matrices

We prove two inequalities regarding the ratio det(A+D)/detA of the determinant of a positive-definite matrix A and the determinant of its perturbation A+D. In the first problem, we study the perturbations that happen when positive matrices are added to diagonal blocks of the original matrix. In the second problem, the perturbations are added to the inverses of the matrices.
The Androgen Insensitive Micropenis: Long-Term Follow-Up Into Adulthood

Aim: To assess the adult stretched penile length (SPL) and sexuality in patients with micropenis who exhibited an inadequate response to exogenous testosterone therapy and were raised as males. Patients and Methods: Patients with micropenis who had an equivocal response to exogenous testosterone therapy and were raised as males were evaluated at adulthood (>17 yr). Results and Conclusions: Twenty patients with micropenis, initial median SPL -3.3 SD below the mean (range -5.5 to -2.6) had a suboptimal response to initial testosterone therapy, median SPL post-treatment -2.7 SD (-3.3 to -2.2), and were raised as males. At adulthood, 90% (18/20) had a micropenis, median SPL -3.4 (-5.9 to -2.2). All have a male gender identity, five are undergoing psychiatric counseling (fear of sexual rejection - five patients, one of whom also has suicidal ideation). Eight have not pursued a sexual relationship; 12 are sexually active, one of whom is bisexual.
Spore Photoproduct Lyase: The Known, the Controversial, and the Unknown

Spore photoproduct lyase (SPL) repairs 5-thyminyl-5,6-dihydrothymine, a thymine dimer that is also called the spore photoproduct (SP), in germinating endospores. SPL is a radical S-adenosylmethionine (SAM) enzyme, utilizing the 5′-deoxyadenosyl radical generated by SAM reductive cleavage reaction to revert SP to two thymine residues. Here we review the current progress in SPL mechanistic studies. Protein radicals are known to be involved in SPL catalysis; however, how these radicals are quenched to close the catalytic cycle is under debate.
Disaggregations in databases

An algebraic foundation of database schema design is presented. A new database operator, namely, disaggregation, is introduced. Beginning with “free” families, repeated applications of disaggregation and three other operators (matching function, Cartesian product, and selection) yield families of increasingly elaborate structure. In particular, families defined by one join dependency and several “embedded” functional dependencies can be obtained in this manner.
Three New Long-Period X-Ray Pulsars Discovered in the Small Magellanic Cloud

The Small Magellanic Cloud is increasingly an invaluable laboratory for studying accreting and isolated X-ray pulsars. We add to the class of compact SMC objects by reporting the discovery of three new long-period X-ray pulsars detected with the Chandra X-Ray Observatory. The pulsars, with periods of 152, 304, and 565 s, all show hard X-ray spectra over the range 0.6-7.5 keV. The source positions of the three pulsars are consistent with known Hα emission sources, indicating they are likely to be Be-type X-ray binary star systems.
Synthesis and Rearrangement of Dispiro-Epoxy-β-Lactams

Abstract α-Methylene-β-lactams are prepared by a Peterson olefination reaction. These substrates can be epoxidized with MCPBA to give the title dispiro-epoxy-β-lactams. Under the influence of boron trifiuoride, these substrates rearrange to spiro-3-ketolactams.
Joint provision of public goods: the consolidation of school districts

Abstract A new methodological approach investigates the factors that cause and inhibit political jurisdictions from jointly providing public services. Previous statistical approaches study whether consolidation occurs but are incapable of exploring with whom it occurs. The Poirier bivariate probit analysis suggests population and property value factors matter more than socio-demographic factors in determining whether two neighboring entities will form a consolidated school district. Small and large districts merge with each other, while medium-sized communities tend not to merge. Contrary to prior studies, neither racial composition, income levels, nor hypothetical school quality has a statistically significant effect on the probability of merging.
Mode predictors in nonlinear systems with identities

Abstract For a nonlinear system of simultaneous equations, the mode of the joint distribution of the endogenous variables in the forecast period is proposed as an alternative to the more usual deterministic or mean predictors. A first method follows from maximizing the joint density of a subset of the endogenous variables, corresponding to stochastic equations only (analogously to FIML estimation, where identities are first substituted into stochastic equations). Then a more general approach is developed, which maintains the identities. The model with identities is viewed as a mapping between the space of the random errors and a hypersurface in the space of the endogenous variables; the probability density is defined, and maximization is performed on such a hypersurface. Experimental results on these two mode predictors (and comparisons with deterministic and mean predictors) are provided for a macro model of the Italian economy.
Galactic warps induced by cosmic infall

Recent ideas for the origin and persistence of the warps commonly observed in disc galaxies have focused on cosmic infall. We present N-body simulations of an idealized form of cosmic infall on to a disc galaxy and obtain a warp that closely resembles those observed. The inner disc tilts remarkably rigidly, indicating strong cohesion due to self-gravity. The line of nodes (LON) of the warp inside R 26.5 ∼ 4.5R d is straight, while that beyond R26.5 generally forms a loosely wound, leading spiral in agreement with Briggs’s rules. We focus on the mechanism of the warp and show that the leading spiral arises from the torques from the misaligned inner disc and its associated inner oblate halo. The fact that the LON of most warps forms a leading spiral might imply that the disc mass is significant in the centre. If the LON can be traced to very large radii in future observations, it may reveal information on the mass distribution of the outer halo. The warp is not strongly damped by the halo because the precession rate of the inner disc is slow and the inner halo generally remains aligned with the inner disc. Thus, even after the imposed quadrupolar perturbation is removed, the warp persists for a few Gyr, by which time another infall event can be expected.