cssi/SciSciGPT-SciSciNet huggingface dataset:
Competitive strategy and plant-level flexibility

Choosing how and where to be flexible is a critical issue for manufacturers, particularly as competition becomes more intense and environments become more turbulent. Unfortunately, attempts by scholars to make useful prescriptions remain hampered by the fragmented nature of the literature on flexibility. The present paper integrates a review of that literature with concepts from organization theory and competitive strategy in proposing two types of flexibility—tactical and strategic—at the plant level. Using canonical correlation analysis and data gathered from multiple US industries, the relationship between competitive strategy and the perceived value of tactical and/or strategic flexibility is explored. Results tentatively indicate significant strategic effects on the choice of flexibility emphasis at the plant level.
Use of NIR and pyrolysis-MBMS coupled with multivariate analysis for detecting the chemical changes associated with brown-rot biodegradation of spruce wood

Near infrared (NIR) spectroscopy and pyrolysis-molecular beam mass spectrometry (py-MBMS) analysis can be used in conjunction with multivariate regression and principal components analysis to differentiate brown-rot-degraded wood from non-degraded spruce and to follow the temporal changes in wood undergoing brown-rot degradation. Regression of NIR test results vs. percent weight loss for Postia placenta- and Gloeophyllum trabeum-infected spruce wood blocks yielded a correlation coefficient of 0.96. Regression of MBMS test results for the same samples yielded a correlation coefficient of 0.96. Principle components analysis was used to differentiate non-infected wood and P. placenta- and G. trabeum-infected wood. These techniques may be used to detect different types of biodegradation and to develop a better understanding of the chemical changes that the wood undergoes when it is subjected to brown-rot biodegradation.
Development of a woman's multiple orgasm pattern: A research case report

Abstract A 36‐year‐old woman with limited previous sexual experience was repeatedly monitored as she learned to stimulate herself digitally to orgasm. During 7 laboratory sessions spanning 5 months, she was recorded physiologically and interviewed in detail about her subjective experiences of orgasm. From session III onward, the subject experienced multiple orgasms in the laboratory. The orgasm frequency ranged from 3 orgasms in 7 minutes (session III) to 7 orgasms in 16 minutes (session VI). Anal pressure was chosen to illustrate the development of her multiple orgasm pattern. The series of regular contractions were more prominent during the initial orgasms of successive sessions. In later orgasms of a session, regular contractions were few in number or did not occur. A drop in pressure, however, invariably related to the start of each signalled orgasm. Her attempts to relate subjective terms to physiologic events call attention to semantic issues in describing orgasm. This research case report can serve...
Oxidative Damage of DJ-1 Is Linked to Sporadic Parkinson and Alzheimer Diseases

Mutations in DJ-1 cause an autosomal recessive, early onset familial form of Parkinson disease (PD). However, little is presently known about the role of DJ-1 in the more common sporadic form of PD and in other age-related neurodegenerative diseases, such as Alzheimer disease (AD). Here we report that DJ-1 is oxidatively damaged in the brains of patients with idiopathic PD and AD. By using a combination of two-dimensional gel electrophoresis and mass spectrometry, we have identified 10 different DJ-1 isoforms, of which the acidic isoforms (pI 5.5 and 5.7) of DJ-1 monomer and the basic isoforms (pI 8.0 and 8.4) of SDS-resistant DJ-1 dimer are selectively accumulated in PD and AD frontal cortex tissues compared with age-matched controls. Quantitative Western blot analysis shows that the total level of DJ-1 protein is significantly increased in PD and AD brains. Mass spectrometry analyses reveal that DJ-1 is not only susceptible to cysteine oxidation but also to previously unsuspected methionine oxidation. Furthermore, we show that DJ-1 protein is irreversibly oxidized by carbonylation as well as by methionine oxidation to methionine sulfone in PD and AD. Our study provides new insights into the oxidative modifications of DJ-1 and indicates association of oxidative damage to DJ-1 with sporadic PD and AD.
Surface-discharging hydrothermal systems at Yucca Mountain: Examining the evidence

This paper discusses exposures of altered rock that have been thought to form by recent discharge of water from depth. They were examined to address a concern that hydrothermal processes could compromise the isolation capability of a potential high-level nuclear waste repository at Yucca Mountain. Suspected hot-spring and hydrothermal-vent deposits are more likely the products of infiltration of meteoric water into newly deposited and still-hot pyroclastic flows >12 Myr ago.
Non-Contact Small Animal Fluorescence Imaging System for Angular-Resolved Tomography

We present design details and initial experimental results obtained with our newly developed fluorescence molecular tomography (FMT) imaging system that can perform non-contact, angular-resolved, multi-directional measurements simultaneously.
Magnetic susceptibility and heat-capacity studies of NiS 2 − x Se x single crystals: A study of transitions at nonzero temperature

Heat-capacity and magnetic-susceptibility studies have been carried out on ${\mathrm{NiS}}_{2\ensuremath{-}x}{\mathrm{Se}}_{x}$ single crystals for $0.38l~xl~0.58$ and $0l~xl~0.71,$ respectively. These and earlier physical measurements document the gradual evolution, with rising $x,$ of the alloys from good insulators to poor metals at low temperatures. The transitions between various magnetically ordered or disordered phases are marked by anomalies in these physical measurements. The trend of magnetic susceptibility with temperature indicates that alloys near the crossover to the highly correlated metallic state exhibit increasing charge-carrier localization with rising temperature; this is ascribed to the dominance of entropic contributions to the free energy. It is stressed that these variations in properties are achieved by isoelectronic substitutions in the anion sublattice that leave the cation sublattice undisturbed.
Biomedical image segmentation via constrained graph cuts and pre-segmentation

In this paper we present a high-fidelity method for 2D and 3D image boundary segmentation. The algorithm is a novel combination of graph-cuts and initial image segmentation. The pre-segmentation using anisotropic vector diffusion and the fast marching method is employed so that the size of the graph being considered is significantly reduced. To further improve the segmentation accuracy, some user guidance is taken into account in finding the minimal graph cut. To this end, a user-friendly graphical user interface (GUI) is developed not only for visualization purposes but for user input and editing as well. The approaches and tools developed are validated on a number of 2D/3D biomedical imaging data, showing the high efficiency and effectiveness of our method.
Roaming times of multi-wireless systems for software defined radio

In this paper, we evaluate the roaming time performance for a reconfigurable multi-mode mobile station (MS) that experiences possible transition from one kind of wireless system standard to another. In future software defined radio systems (SDR) (IEEE Commun Mag 2000; 138–143, IEE 1998; 1–6, IEEE 1999; 1212–1216, IEEE Commun Mag 1995; 33), reconfigurability of the MS is achieved by downloading the system configuration software code over the wireless channel. For evaluation of the roaming times, a generalized state diagram of the multi-mode MS is presented. We focus on evaluating the times for sensing the universal pilot channel, classic base station pilot channel, association and connection establishment signaling are included. We investigate the effects of packet successful transmission probability over the wireless channel. We also consider the effects of the system resource blocking probability, MS resource blocking probability, and signaling bit rate over the universal base station channel for different cases and design scenarios. Such evaluations are important for prior design of SDR mobile terminal and universal base station in global roaming situations. We include some analysis results from many obtained. These show the feasibility of wireless software download, and switching between different wireless standard as the mobile station roams. Copyright © 2003 John Wiley & Sons, Ltd.
Structure development in aerogel-processed nanocrystalline alkaline earth oxides as revealed by SANS

Nanocrystalline MgO, CaO and SrO were prepared according to a modified aerogel process (AP). Small-angle neutron scattering (SANS) was used to probe the nanoscale structural features of these materials after each stage of the synthetic process, including hydrolysis, supercritical drying and calcining. SANS data were interpreted using a classical analysis involving power-law and Guinier regimes, and by application of the maximum entropy method. Results are compared with previously published structural data based on X-ray diffraction, electron microscopy and gas adsorption. It is found that the gel hydrolysis product suspended in methanol and toluene exhibits rod-like scattering at small length scales. This is consistent with a filiform morphology previously reported for air-dried Mg(OH) 2 alcogel, yet SANS data for air-dried alcogels tested in this study indicate no evidence for low-dimensional structure on any length scale. A previous assertion of mass fractal structure in the AP aerogels and oxides was not confirmed by the present data. Instead, surface fractal scattering was found to be the most dominant characteristic feature associated with the SANS data for all AP powders examined. Additionally, MgO and CaO exhibited a correlation peak that corresponds to liquid-like ordering at Bragg length scales of 5.9 nm and 20.3 nm, respectively. These values are roughly consistent with previous independent estimates of primary particle size, suggesting that local packing of primary crystallites is facilitated by the calcination/dehydration process. An alternative interpretation treats these features as Guinier scattering regions. Fitting of results using the unified Guinier/power-law equation yields sphere-equivalent radii for the primary particles that are nearly identical to the Bragg lengths calculated from the positions of the maxima. Air-dried alcogels produced very weak maxima that could be interpreted either as correlation peaks or as Guinier regions. No maxima were observed for aerogel samples. Maximum entropy analysis using a spherical shape factor produced interesting but complex results for the calculated volume size distributions of these materials. Overall, the observed trend shows an increase in structural feature size with increasing metal cation size.
Conserving connectivity: some lessons from mountain lions in Southern California.

Habitat corridors can be essential for persistence of wildlife populations in fragmented landscapes. Although much research has focused on identifying species and places critical for conservation action, the conservation literature contains surprisingly few examples of corridors that actually have been protected and so provides little guidance for moving from planning through implementation. We examined a case study from southern California that combines monitoring of radio-collared mountain lions (Puma concolor) with an assessment of land-protection efforts to illustrate lessons learned while attempting to maintain ecological connectivity in a rapidly urbanizing landscape. As in many places, conservation scientists have provided science-based maps of where conservation efforts should focus. But implementing corridors is a business decision based not solely on ecological information but also on cost, opportunity cost, investment risk, and other feasibility considerations. Here, the type and pattern of development is such that key connections will be lost unless they are explicitly protected. Keeping pace with conversion, however, has been difficult, especially because conservation efforts have been limited to traditional parcel-by-parcel land-protection techniques. The challenges of and trade-offs in implementation make it clear that in southern California, connectivity cannot be bought one parcel at a time. Effective land-use plans and policies that incorporate conservation principles, such as California's Natural Communities Conservation Planning program, are needed to support the retention of landscape permeability. Lessons from this study have broad application, especially as a precautionary tale for places where such extensive and intensive development has not yet occurred. Given how limiting resources are for biodiversity conservation, conservationists must be disciplined about where and how they attempt corridor protection: in rapidly fragmenting landscapes, the opportunity for success can be surprisingly fleeting.
Multisplitting with different weighting schemes

Parallel algorithms generated by multisplittings are considered. A parallel algorithm may be formed, first, by concurrently executing the iteration associated with each splitting, and second, by forming a weighted sum of these computations. However, it is not imperative that the weighting be done last. Convergence results are obtained for a variety of other weighting schemes. In particular, it is shown that preweighting is in some cases more desirable than the traditional postweighting. Furthermore, we indicate how one can use a symmetric weighting scheme to obtain a good multisplitting version of the SSOR preconditioner. These algorithms are illustrated by computations done on an Alliant $\text{FX} /8$ .
A Simple Method to Generate Chromosomal Mutations in Lactobacillus plantarum Strain TF103 to Eliminate Undesired Fermentation Products

Gram-positive bacteria have been explored to convert lignocellulosic biomass to biofuel and bioproducts. Our long-term goal is to create genetically engineered lactic acid bacteria (LAB) strains that convert agricultural biomass into ethanol and other value-added products. The immediate approaches toward this goal involve genetic manipulations by either introducing ethanol production pathway genes or inactivating pathways genes that lead to production of undesired byproducts. The widely studied species Lactobacillus plantarum is now considered a model for genetic manipulations of LAB. In this study, L. plantarum TF103 strain, in which two of the chromosomal L-ldh and D-ldh genes are inactivated, was used to introduce additional mutations on the chromosome to eliminate undesired fermentation products. We targeted the acetolactate synthase gene (als) that converts pyruvate to acetolactate, to eliminate the production of acetoin and 2,3-butanodial. A pBluescript derivative containing sections of the als coding region and an erythromycin resistance gene was directly introduced into L. plantarum TF103 cells to create mutations under selection pressure. The resulting erythromycin resistant (Emr) TF103 strain appears to have chromosomal mutations of both the als and the adjacent lysP genes as revealed by polymerase chain reaction and Southern blot analyses. Mutations were thus generated via targeted homologous recombination using a Gram-negative cloning vector, eliminating the use of a shuttle vector. This method should facilitate research in targeted inactivation of other genes in LAB.
Dual function catalysts. Dehydrogenation and asymmetric intramolecular Diels-Alder cycloaddition of N-hydroxy formate esters and hydroxamic acids: evidence for a ruthenium-acylnitroso intermediate.

The chiral ruthenium salen complex, 13b, functions as an efficient catalyst for the sequential oxidation and asymmetric Diels−Alder cycloaddition of hydroxamic acids and N-hydroxy formate esters. This result provides evidence for the formation of a ruthenium−nitroso formate (acyl nitroso) intermediate. The Diels−Alder precursors are prepared from simple building blocks, and the cycloadducts, bridged oxazinolactams, can serve as useful intermediates in organic synthesis.
Sensory Nerves Promote Ozone-induced Lung Inflammation in Mice

Genetically manipulated mice exhibiting altered innervation of the airways were used to examine the role of sensory nerves in ozone-induced lung inflammation. Transgenic mice expressing nerve growth factor (NGF) from the lung-specific Clara cell secretory protein (CCSP) promoter exhibit hyperinnervation of the airways by sympathetic and tachykinin-containing sensory nerve fibers. Mice carrying a mutation in the low-affinity NGF receptor (NGFR) gene possess deficits in sensory innervation. CCSP-NGF transgenic mice exhibited a twofold increase in the number of lung lavage neutrophil level whereas NGFR knockout mice exhibited a nearly 50% decrease in neutrophilic inflammation compared with wild-type mice 18 h after ozone inhalation. Treatment with neurokinin receptor antagonists reduced the level of neutrophilic inflammation in both wild-type and CCSP-NGF mice. Examination of lavage fluid cytokine concentrations revealed that 4 h after ozone exposure CCSP-NGF mice produced significantly higher amounts of the chemokine KC than wild-type mice exposed to ozone. The results of this study indicate that sensory nerves are important mediators of ozone-induced inflammation in mice.
A mass transfer origin for blue stragglers in NGC 188 as revealed by half-solar-mass companions

In open star clusters, where all members formed at about the same time, blue straggler stars are typically observed to be brighter and bluer than hydrogen-burning main-sequence stars, and therefore should already have evolved into giant stars and stellar remnants. Correlations between blue straggler frequency and cluster binary star fraction, core mass and radial position suggest that mass transfer or mergers in binary stars dominates the production of blue stragglers in open clusters. Analytic models, detailed observations and sophisticated N-body simulations, however, argue in favour of stellar collisions. Here we report that the blue stragglers in long-period binaries in the old (7 × 10(9)-year) open cluster NGC 188 have companions with masses of about half a solar mass, with a surprisingly narrow mass distribution. This conclusively rules out a collisional origin, as the collision hypothesis predicts a companion mass distribution with significantly higher masses. Mergers in hierarchical triple stars are marginally permitted by the data, but the observations do not favour this hypothesis. The data are highly consistent with a mass transfer origin for the long-period blue straggler binaries in NGC 188, in which the companions would be white dwarfs of about half a solar mass.
The effect of β-aminopropionitrile on acid hydrolases and selected metabolites in oro-facial structures of foetal rats

Administration to pregnant rats of β-aminopropionitrile (BAPN) produced marked alterations in the activities of a number of enzymes and tissue components associated with glycosaminoglycan metabolism in the palates, mandibles and Meckel's cartilages of 16-day BAPN-treated foetal rats. Alkaline phosphatase, β-galactosidase and N-acetyl-β-D-glucosaminidase activities were significantly increased in palates and Meckel's cartilages but reduced in the mandibles of BAPN-treated foetal rats. Acid phosphatase activity increased in palates and Meckel's cartilages but remained constant in mandibles of foetal rats exposed to BAPN. The activity of β-glucuronide increased significantly in all three oro-facial structures of foetal rats treated with BAPN. The alterations in enzyme activities were accompanied by changes in the gross biochemical composition of each of the three structures. Uronic acid and hydroxyproline levels were significantly increased in mandibles and Meckel's cartilages but were reduced in the palates of BAPN-treated rats. Hexosamine levels were also increased in Meckel's cartilages but remained unchanged in palatal tissues of BAPN-treated foetal rats and decreased in mandibles of BAPN-treated foetal rats. It is concluded that the non-uniform effect of BAPN on glycosaminoglycan metabolism in developing oro-facial structures may be accounted for by differences in cellular composition of the various structures.
Regularities and similarities in plasma broadened spectral line widths (Stark widths)

Abstract Regularities and similarities in plasma broadened line widths have been studied by a comprehensive analysis of existing experimental data. Regularities are expected on the basis of general atomic structure considerations, and should be evident for spectral series, for corresponding transitions in homologous atoms and in isoelectronic sequences. Furthermore, similarities of line widths are expected for multiplets, supermultiplets and, to a lesser degree, for transition arrays. A comprehensive examination of literature data has been undertaken, which shows generally a close adherence of the measured data to the expected regularities. A few notable exceptions are also given.
Cleaning of GaN surfaces

The work described in this paper is part of a systematic study of surface cleaning and ohmic contact strategies for GaN. The goal of this investigation was to determine the most effective methods of wet chemical and thermal desorption cleaning for the removal of oxygen (O) and carbon (C) prior to metallization. Hydrochloric (HC1) and hydrofluoric (HF) acid-based cleaning treatments were compared, and thermal desorption as a function of temperature was characterized by sequential heating under ultra high vacuum (UHV) conditions. Auger electron spectroscopy (AES) analysis was used to monitor the presence of surface O and C throughout the study. For the removal of surface oxide, HCl-based solutions were found to be most effective; under as-cleaned, air-exposed conditions, HC1:DI H2O (1:1) solution resulted in the lowest levels of residual O and C. However, HF-based solutions resulted in more effective thermal desorption of C from the surfaces. In contrast to the results typically observed in the thermal desorption cleaning of GaAs, complete removal of oxygen and carbon from airexposed GaN surfaces was not seen using vacuum heating alone, even to temperatures where GaN decomposition occurs (>800-900°C). The results of this study indicate that the presence of oxygen and carbon on the GaN surface is persistent even to high temperatures, and that further in-situ cleaning methods must be added to obtain spectroscopically clean GaN surfaces.
Balance in leader and follower perceptions of leader-member exchange: Relationships with performance and work attitudes

Abstract Using a sample of 285 matched pairs of employees and supervisors, we explore the extent to which congruence in leader and follower ratings of LMX quality is related to follower job performance and work attitudes. An original conceptual model is introduced that identifies four combinations of leader and follower LMX ratings: balanced/low LMX (low leader and follower LMX), balanced/high LMX (high leader and follower LMX), follower overestimation (low leader LMX/high follower LMX), and follower underestimation (high leader LMX/low follower LMX). As expected, balanced/low (high) LMX relationships were associated with relatively low (high) levels of follower job performance, organizational commitment, and job satisfaction, while the incongruent combinations generally yielded intermediate levels of follower outcomes. However, follower underestimation was also related to high levels of follower job performance, whereas follower overestimation was associated with high levels of follower satisfaction and organizational commitment. Implications of these findings for future LMX research are considered.
PERIPHERAL ENDOCRINOPATHY CAUSING SEXUAL PRECOCITY IN ALBRIGHT'S SYNDROME

To elucidate the cause of sex precocity in Albright's syndrome, three girls (ages 1 10/12, 4 6/12, and 5 1/12 years) with polyostotic fibrous dysplasia and cafe-au-lait spots were studied. Periodic vaginal bleeding was present in all and skeletal maturation significantly advanced. Plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations were at or below the lowest detectable level of the assay (2.0 mIU/ml) awake and during sleep; radioimmunoassay of FSH in 24 hour urine samples showed no elevation over childhood levels. By contrast, the estrogen levels were markedly elevated; plasma estradiol ranged between 606 and 795 pg/ml and estrone between 149 and 175 pg/ml, concentrations greater than Observed during normal follicular and luteal phases of adult menstrual cycles. Plasma progesterone, undetectable (< 20 pg/ ml) in serial intermenstrual measurements suggested lack of ovulation. These findings suggest the precocity of all three children was due to primary ovarian dysfunction rather than being of central origin. Autonomous hyperfunction of the peripheral target glands as the pathogenetic mechanism underlying the several endocrinopathies of this syndrome is further suggested by the coexistence of nodular adrenal hyperplasia in one of the girls whose elevated plasma cortisol levels failed to suppress with dexamethasone and plasma ACTH level was low.
An individual-based model of bay anchovy population dynamics in the mesohaline region of Chesapeake Bay

Bay anchovy Anchoa mitichilli population dynamics in the mesohaline region of Chesapeake Bay are described and analyzed with an individual-based model. The model begins with spawning by individual females and simulates the daily growth and mortality of each female's progeny as they develop through the egg, yolk-sac larva, (feeding) larval, juvenile, and adult stages in a single, well-mixed compartment. The model runs for 50 yr. Eggs and yolk-sac larvae develop at rates dependent on temperature, and die at fixed daily rates. All feeding individuals (larvae, juveniles, and adults) consume zooplankton and grow according to defined bioenergetics relationships. Encounters, attacks and captures of prey, and the probability that feeding individuals will die are treated stochastically using Monte Carlo techniques. Net immigration of spawners into the modelled box each year is simulated in 2 ways: multiplier of survivors and as a constant number. Model predictions of stage-specific growth and survival rates, and diets were similar for multiplier and constant immigration simulations, and both were similar to observed values. Density-dependent growth of larvae and juveniles led to a negative relationship between mean length and number of recruits and to density-dependent survival of larvae and juveniles. Density-dependent growth was due to anchovy consumption reducing prey densities, and not due to temperature effects on numbers surviving and growth. First-year survivorship was lower in years of high egg production than in years of low egg production. Larval growth and survival rates were positively related to recruitment, but the reverse was true for juveniles. Years of high recruitment were not years of high first-feeder production, but rather were years of high larval survival. The model simulates a single spatial box with a forced net immigration of spawners and assumes density-independent spawning and mortality processes. The model quantifies the basic processes leading to recruitment of bay anchovy and sets the stage to explore potential compensatory responses of anchovy.
Some new chemistry of perfluoro-t-butylsilver

Abstract Perfluoro-t-butylsilver, prepared by the reaction of silver fluoride with perfluoroisobutene,has been used to prepare new perfluoro-t-butyl derivatives in good yield.
Blind walking of a planar bipedal robot on sloped terrain

Simple intuitive control strategies can be used to compel bipedal robots to walk over sloped terrain. We describe an algorithm for walking dynamically and steadily over sloped terrain with unknown slope gradients and transition locations. The algorithm is developed based on geometric considerations. The overall algorithm is very simple and does not require the biped to have an extensive sensory system for walking over moderate slopes. The ground is detected blindly using only foot contact switches. Using a few simple strategies, we have compelled a simulated 7-link planar biped to walk up and down slopes and over rolling terrain.
Dress as a Cultural Sub-system: A Unifying Metatheory for Clothing and Textiles

Dress as a cultural sub-system, based on technological, social structural, and ideological components, is proposed as a unifying metatheory for the academic discipline of clothing and textiles. This culturally based model, intended as a paradigm in which both new and existing psychological, sociological, economic, and other theories operate, is holistic since it incorporates the individual, the group, and the cultural system as critical units of analysis in an understanding of the pan-human phenomenon of dress. As a cultural sub-system, dress is a dynamic, interacting system, unbounded by time and space, that articulates directly with the larger cultural system in which dress operates. This metatheory unifies the breadth of concerns in clothing and textiles and clarifies the symbiotic relationship of the sub-fields to one another. It also provides a framework for a more critical review of implications of the discipline's theoretical and applied value.
Seneca’s Ethics Viewed from a Modern Standpoint

Wolfgang Yourgrau’s interest comprised many fields. It was strong in physics, philosophy of science, and history of science and included the urge to understand nonscientific disciplines in general scientific terms. This was clear in numerous stimulating conversations between him and the present author. In his article published in Vistas of Physical Reality (E. Laszlo and E. B. Sellon, editors, Plenum Press, New York, 1976), entitled “Some Reflections on Philosophy of Science,” he offers and advances a pluralistic approach to philosophy of science, suggesting that no single epistemology can support all subjects, not even all sciences. Nevertheless he tended to dismiss purported disciplines which reject the scientific spirit. Recalling this, and aware of his general interest in history, I offer for Yourgrau’s Memorial Volume a paper which interested him and which might exemplify a quasiscientific approach to a subject which appears rudderless without some relevance to science. It was presented in Cordoba, Spain, on the nineteen hundredth anniversary of Seneca’s birth and published in a volume in his honor entitled Actas Del Congreso International De Filsofia in 1967.
Negative regulation of antigen receptor signaling in lymphocytes

The negative regulation of antigen receptor signal transduction is essential for the maintenance of thresholds for activation in lymphocytes. CD45 and SHP-1 are tyrosine phosphatases that are important in maintaining the proper level of tyrosine phosphorylation. Regulation of the src family of tyrosine kinases is mediated by the coordinated action of the tyrosine kinase Csk and the tyrosine phosphatase CD45. B cell receptor signaling is negatively regulated by the recruitment of SHP-1 to bind the B cell transmembrane proteins CD22 and FcgammaRIIb1. SHP-1 also functions to negatively regulate T cell receptor signaling by dephosphorylating and inactivating tyrosine kinases.
Emerging Community Noise Reduction Approaches

An overview of the current NASA research portfolio in the area of aircraft noise reduction is presented. The emphasis of the research described herein is on meeting the aggressive near- and mid-term national goals for reducing aircraft noise emissions, which NASA internal studies have shown to be feasible using noise reduction technologies currently being developed in-house or in partnership with NASA s industry and academic partners. While NASA has an active research effort in airframe noise reduction, this overview focuses on propulsion noise reduction only.
as Signifier: Considering the Semantic Field of School Literacy

This article examines the use of the term within the educational and national media and by the newspaper and interested parties in 1 college town. Data collected include articles in literacy journals; a search of 5 daily newspapers in the US and other periodicals and TV news; a search of 1 local newspaper; and interviews with 70 teachers, administrators, university faculty, and “concerned citizens” in a mid-sized city in the Southwestern us with a major public university. Using the “discourse-centered approach to culture” proposed by Sherzer (1987) as a revision of the Sapir-Whorf hypothesis, our interpretive analysis of the data argues that the disputes surrounding the term have as much to do with cultural, political, and economic issues confronting the US, and in particular the Southwest, as they do with any philosophical or professional conversation about the “best way” to teach children to read. The implication is that if literacy research is to retain both its legiti...
Rheological, structural, and stress evolution of aqueous Al2O3 :Latex tape-cast layers

The rheological, structural, and stress evolution of aqueous alumina (Al2O3):latex tape-cast layers of varying composition were studied by shear rheology, direct visualization, and a controlled environment stress measurement device. Their low shear viscosity was nearly independent of the alumina:latex ratio for binary mixtures whose particle size ratio (λ=Dalumina:Dlatex) approached unity, but varied over an order of magnitude for systems with particle size asymmetry. Direct visualization of these mixtures revealed that particle flocculation occurred as their total solids loading increased. Their structure was characterized at intermittent points during the drying process by imaging freeze-dried samples using scanning electron microscopy (SEM). Their corresponding stress histories exhibited three distinct regions: an initial period of stress rise, followed by a stress maximum, and, finally, a period of stress decay. Pure alumina layers exhibited a maximum stress of ∼1 MPa and a residual stress below 0.01 MPa. Pure latex films exhibited a maximum stress of ∼0.1 MPa and only a slight stress decay. The ceramic phase dominated the initial period of stress rise, while the latex phase strongly influenced the residual stress of composite layers cast from alumina:latex suspensions. Their maximum drying stress increased with decreasing Al2O3 particle size, whereas their residual stress increased with increasing latex Tg.
Surface Tension of Alkaline‐Earth Borates Containing 3 Mole % Potassium Oxide

The surface tensions of a series of barium, strontium, and calcium borates, each containing 3 mole % of K2O to counteract immiscibility, were measured by a ring detachment method. The order Ca < Sr < Ba was established for surface tensions of melts containing up to 40 mole % MO (alkaline-earth oxide). Positive temperature coefficients of surface tension were observed for melts of low MO content. An interpretation of the observed inversions of surface tension from the order of ionic potential of the cations for these systems, as well as for other systems previously studied, is presented in terms of the Gibbs adsorption equation. A connection is indicated between inversions in the order of surface-tension values and the presence of positive temperature coefficients.
Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter.

Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early ( 40% mass loss) decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood < maple < maple-oak mixture < oak). In the field, mass loss was minimal (< 10%) over the first 50 days (January-February), even for labile litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C) ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N) accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab conditions.
A Study of the Optimum Design of Wide-Band Parametric Amplifiers and Up-Converters

Single-diode parametric amplifiers or up-converters using multiple-resonator filters as coupling networks can be made to have considerably larger bandwidths than corresponding amplifiers having single-resonator coupling circuits. Data are presented from which the coupling-filter bandwidths required for given coupling network complexity, diode parameters, and required gain can be determined for both parametric amplifiers and up-converters. In the cases of nondegenerate parametric amplifiers and up-converters, the fact that the diode must be brought to resonance at more than one frequency has an added limiting effect on bandwidth. Some trial amplifier designs are shown, and important considerations in the synthesis of the coupling filters are noted. It is seen that for the case upper-sideband up-converters, if a filter having n resonators is used in both the input and upper-sideband circuits, then the over-all response can be made to correspond to that of a filter with 2n resonators. The gain characteristics of the trial amplifier designs as determined with a digital computer are included. Computed responses ranging in bandwidth from 9 to 27 per cent are obtained for multi-resonator designs having C/sub 1// C/sub 0/ = 0.25.
Implementation of 2-D separable-in-denominator digital filters for real-time processing

The general decomposition of separable in denominator 2-D discrete systems is reported. Several novel realizations for separable-in-denominator 2-D digital filters are presented. The number of required multipliers and additions for the implementation of these structures are reduced in comparison with the previously reported structures. The proposed realizations possess high degrees of parallelism/modularity which are suitable for VLSI design and implementation.
Large-Scale Microscopic Simulation : Toward an Increased Resolution of Transportation Models

Recent years have witnessed an interest in increasing the resolution of transportation models to allow them to better address emerging transportation issues, such as concerns about emissions, air quality, and emergency preparedness. Microscopic simulation models, especially those that combine routing logic with accurate modeling of traffic flow dynamics, have vast untapped potential for modeling large-scale transportation networks and for achieving the resolution level required for addressing such emerging issues. Building and calibrating such models, however, is quite challenging and is currently not widely understood. This paper describes the process of developing and calibrating a large-scale microscopic model of Chittenden County, Vt., an area of about 1,400 km2 (540 mi2 ) . The model was developed primarily using readily available data to which most metropolitan planning organizations are expected to have access. Following a brief description of how the network was coded and the traffic demand specif...
Felid sex identification based on noninvasive genetic samples

We developed two tests for sex identification of felids using y-chromosome deletions in the zinc-finger and amelogenin regions. These tests provide positive results for both males and females, while reducing the need to co-amplify microsatellites to test for DNA quality in hair and scat samples. Furthermore, the y-chromosome deletions are absent in a wide-range of prey species; thus, when these tests are used on scat samples, potential contamination caused by prey DNA incidentally extracted, is minimized.
Population, community and ecosystem effects of exotic herbivores: A growing global concern

Exotic herbivores represent a serious threat to native biodiversity, producing large scale changes in native communities and altering ecosystem processes. In this special issue, we present a series of case studies and reviews from different areas of the world that highlight (1) the consequences of herbivore introductions are a global problem; (2) they can result in wholesale shifts in the distribution of dominant plants on the landscape and; (3) the effects of herbivore introductions extend from the population to the community and ecosystem level. These studies suggest that introduced herbivores often retard ecosystem recovery after disturbance, facilitate invasion of plant species and can act as selective agents on native plant communities. These studies also suggest that several topics, including facilitation between exotic herbivores and exotic plants and animals (i.e., invasional meltdown) and the effect of exotic herbivores on ecosystem processes, require more research attention. Overall the papers in this special feature suggest that introduced herbivores are a global problem with wide-ranging ecological and evolutionary effects.
HDTrans: an open source, low-level dynamic instrumentation system

Dynamic translation is a general purpose tool used for instrumenting programs at run time. Performance of translated execution relies on balancing the cost of translation against the benefits of any optimizations achieved, and many current translators perform substantial rewriting during translation in an attempt to reduce execution time. Our results show that these optimizations offer no significant benefit even when the translated program has a small, hot working set. When used in a broader range of applications, such as ubiquitous policy enforcement or penetration detection, translator performance cannot rely on the presence of a hot working set to amortize the cost of translation. A simpler, more maintainable, adaptable, and smaller translator appears preferable to more complicated designs in most cases.HDTrans is a light-weight dynamic instrumentation system for the IA-32 architecture that uses some simple and effective translation techniques in combination with established trace linearization and code caching optimizations. We present an evaluation of translation overhead under both benchmark and less idealized conditions, showing that conventional benchmarks do not provide a good prediction of translation overhead when used pervasively.A further contribution of this paper is an analysis of the effectiveness of post-link static pre-translation techniques for overhead reduction. Our results indicate that static pre-translation is effective only when expensive instrumentation or optimization is performed.
Preventing Ultimate Harm as the Justification for Biomoral Modification

Most advocates of biogenetic modification hope to amplify existing human traits in humans in order to increase the value of such traits as intelligence and resistance to disease. These advocates defend such enhancements as beneficial for the affected parties. By contrast, some commentators recommend certain biogenetic modifications to serve social goals. As Ingmar Persson and Julian Savulescu see things, human moral psychology is deficient relative to the most important risks facing humanity as a whole, including the prospect of Ultimate Harm, the point at which worthwhile life is forever impossible on the planet. These risks can be mitigated, they say, by enhancing moral psychology in novel ways. Persson and Savulescu argue that some parents should modify the underlying biogenetics of their children's moral psychology, if such measures were safe and effective, but they admit these interventions may not decouple humanity from Ultimate Harm. Neither are these modifications the only options, they concede, for addressing risks to humanity. Even with these concessions, saving humanity from itself is a fairly poor reason to modify the moral psychology of children. In most ways, adults would be better candidates, morally speaking, for modifications of psychology. Even then, there is no direct link between morally enhanced human beings and the hoped-for effect of better protection from Ultimate Harm. Asserting a general duty of all to contribute to the avoidance of Ultimate Harm is a better moral strategy than intervening in the moral psychology of some, even though meeting that duty may involve substantial interference with the free exercise of one's interests.
A class of perfect graphs containing P 6

Let P6 denote the induced path on six nodes. We prove that if a perfect graph G contains P6 as an induced subgraph but not two families introduced by Conforti and Cornuejols then G is bipartite or disconnected, or G has a star cutset.
Mortality among patients with pleural effusion undergoing thoracentesis.

Of the 1.5 million people diagnosed with pleural effusion in the USA annually, ∼178 000 undergo thoracentesis. While it is known that malignant pleural effusion portends a poor prognosis, mortality of patients with nonmalignant effusions has not been well studied. This prospective cohort study evaluated 308 patients undergoing thoracentesis. Chart review was performed to obtain baseline characteristics. The aetiology of the effusions was determined using standardised criteria. Mortality was determined at 30 days and 1 year. 247 unilateral and 61 bilateral thoracenteses were performed. Malignant effusion had the highest 30-day (37%) and 1-year (77%) mortality. There was substantial patient 30-day and 1-year mortality with effusions due to multiple benign aetiologies (29% and 55%), congestive heart failure (22% and 53%), and renal failure (14% and 57%, respectively). Patients with bilateral, relative to unilateral, pleural effusion were associated with higher risk of death at 30 days and 1 year (17% versus 47% (hazard ratio (HR) 2.58, 95% CI 1.44–4.63) and 36% versus 69% (HR 2.32, 95% CI 1.55–3.48), respectively). Patients undergoing thoracentesis for pleural effusion have high short- and long-term mortality. Patients with malignant effusion had the highest mortality followed by multiple benign aetiologies, congestive heart failure and renal failure. Bilateral pleural effusion is distinctly associated with high mortality.