cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of crude oil on gas exchange functions of Juncus roemerianus and Spartina alterniflora

The effect of crude oil on gas exchange functions of Juncus roemerianus and Spartina alterniflora, two important U.S. Gulf Coast plant species, were examined. Plants were exposed to petroleum hydrocarbons (Mexican Sour type) mixed with water at 4.4 mL L−1 (2 L m−2). Coating entire leaf with oil resulted in cessation of photosynthetic activity. Partial leaf exposure to oil resulted in net photosynthesis decrease in both species shortly after exposure. Net photosynthesis remained within 71 and 94% of control plants in J. roemerianus during the first four weeks of the experiment. In S. alterniflora, photosynthetic rates averaged between 53 to 80% of control plants during the same period. Four weeks following the partial oiling, net photosynthesis began to improve in both species. Partial oil coverage of leaves of both species resulted in reduction in normal photosynthetic activity with no lethal effects. By the end of the laboratory study, there was no significant reduction in production of new shoots or the overall growth of either species.
An accelerated clinical chairside technique for casting overdenture attachment copings

An accelerated technique for casting a direct-pattern post and core restoration for use in fixed prosthodontics has been previously described. Similar techniques for use in removable prosthodontics show potential for clinical use, specifically for the fabrication of radicular stud overdenture attachments and their corresponding copings. The procedure uses a chairside technique and readily available components to fabricate a direct, acrylic resin pattern combining the elements of a cast coping with a fixed radicular attachment. This pattern can subsequently be invested, cast, finished and polished, luted, and attached to the removable prosthesis in a single clinical appointment.
Acceleration of Euclidean algorithm and extensions

We accelerate the extended Euclidean algorithm for integers, the rational number reconstruction, and consequently, the stage of the recovery of the solution of a nonsingular integer system of linear equations via Hensel's lifting. The acceleration is by the order of magnitude and yields nearly optimal randomized algorithms. In the highly important case of Toeplitz, Hankel, and Toeplitz/Hankel-like linear systems, the accleration is potentially practical.
Genetic algorithm convergence study for sensor network optimization

Abstract This paper describes optimization of a sensor network by a Genetic Algorithm (GA). The system developed automatically generates the optimization problems depending on the events happening in the environment and constructs a GA with the appropriate internal structure for the problem at hand. GA finds the quasioptimal combination of sensors that can detect and/or locate the targets. An optimal combination is the one that minimizes the power consumption of the entire sensor network and gives the best accuracy of location of desired targets. The paper attempts to determine the percentage of the total search space (PTSS) that should be covered by GA in order to obtain consistent quasioptimal solutions in different runs. The second goal is to determine the relationship between the population size and the GA stopping criteria that for a given PTSS ensures the best performance of GA. The study is performed for the sensor network optimization problem with three targets.
Discriminating inhalational anthrax from community-acquired pneumonia using chest radiograph findings and a clinical algorithm.

Abstract Background: Limiting the effects of a large-scale bioterrorist anthrax attack will require rapid and accurate detection of the earliest victims. We undertook this study to improve physicians' ability to rapidly detect inhalational anthrax victims. Methods: We conducted a case-control study to compare chest radiograph findings from 47 patients from historical inhalational anthrax cases and 188 community-acquired pneumonia control subjects. We then used classification tree analyses to derive an algorithm of chest radiograph findings and clinical characteristics that accurately and explicitly discriminated between inhalational anthrax and community-acquired pneumonia. Results: Twenty-two of the 47 patients from historical inhalational anthrax cases (46.8%) had reported chest radiograph findings. All 22 case patients (100%) had mediastinal widening, pleural effusion, or both. However, 16 case patients (72.7%) also had infiltrates. In comparison, all 188 community-acquired control subjects had reported chest radiographs. Of these, 127 control subjects (67.6%) had infiltrates, 43 control subjects (22.9%) had pleural effusions, and 15 control subjects (8.0%) had mediastinal widening. A derived algorithm with three predictor variables (chest radiograph finding of mediastinal widening, altered mental status, and elevated hematocrit) is 100% sensitive (95% confidence interval [CI], 73.5 to 100) and 98.3% specific (95% CI, 95.1 to 99.6). The derivation process used 12 patients with inhalational anthrax and 177 control subjects with community-acquired pneumonia who had information available for all three variables. Conclusions: There are significant chest radiograph differences between inhalational anthrax and community-acquired pneumonia, but none of the chest radiograph findings are both highly sensitive and highly specific. The derived clinical algorithm can improve physicians' ability to discriminate inhalational anthrax from community-acquired pneumonia, but its utility is limited to previously healthy individuals and its accuracy may be limited by missing values.
Human cutaneous mechanoreceptors during regeneration: Physiology and interpretation

Percutaneous microneurography was used to record activity from single cutaneous afferents reinnervating the glabrous skin of the hand. Recordings were obtained from 6 months to 10 years after complete transsection of the median and/or ulnar nerves with subsequent repair. Transitional properties in the discharge behavior and receptive field characteristics of regenerating afferents were detected during the early stages of regeneration, when axonal maturation was still in progress; these may contribute to the slow time course of sensory recovery. Properties of reinnervated receptors long after nerve repair, when regeneration can be considered complete, indicated a correlation between electrophysiological findings and the final state of clinical recovery. The insights into the neural basis of sensory deficits provided by single-unit microneurography are not yielded by conventional study of the compound action potentials. This technique reveals new information about the pathophysiological nature of peripheral nerve injury and leads to a reinterpretation of clinical deficits.
The properties of the mitochondrial succinate-cytochrome c reductase

Abstract The cytochromes b and b T of pigeon heart mitochondria have half-reduction potentials ( Em 's) of +30 mV and −30 mV at pH 7.2. The midpoint potentials of these cytochromes become more negative by 30–60 mV per pH unit when the pH is made more alkaline. Detergents may be used to prepare a succinate-cytochrome c reductase free of cytochrome oxidase in which the activation of electron transport induced by oxidation of cytochrome c 1 causes the half-reduction potential of cytochrome b T to become at least 175 mV more positive than in the absence of electron transport. This change is interpreted as indicating that the primary energy conservation reaction at site 2 remains fully functional in the purified reductase. Preliminary electron paramagnetic resonance spectra of the succinate-cytochrome c reductase as measured at near liquid helium temperatures are presented.
On the connectivity of certain graphs of high girth

Let q be a prime power and k?2 be an integer. Lazebnik et al. (Rutcor Research Report RRR 99-93, 1993; Bull. AMS 32 (1) (1995) 73) determined that the number of components of certain graphs D(k,q) introduced by Lazebnik and Ustimenko (Discrete Appl. Math. 60 (1995) 275) is at least qt-1 where t=?(k+2)/4?. This implied that these components (most often) provide the best-known asymptotic lower bound for the greatest number of edges in graphs of their order and girth. Lazebnik et al. (Discrete Math. 157 (1996) 271) showed that the number of components is (exactly) qt-1 for q odd, but the method used there failed for q even. In this paper we prove that the number of components of D(k,q) for even q>4 is again qt-1 where t=?(k+2)/4?. Our proof is independent of the parity of q as long as q>4. Furthermore, we show that for q=4 and k?4, the number of components is qt.
Efficacy of increasing physical activity to reduce children's visceral fat: A pilot randomized controlled trial

Objective. To examine whether differentially targeting physical activity within the context of pilot family-based pediatric weight control treatment results in differential change in abdominal fat,...
Comprehensive study of biomass fly ash in concrete: Strength, microscopy, kinetics and durability

Abstract ASTM (American Standard Testing and Materials) C 618 prohibits use of biomass fly ash in concrete. This document systematically investigates the strength, microscopic study and durability (mitigation of Alkali Silica Reaction (ASR) expansion) of biomass fly ash concrete (cement partially replaced by fly ash) and kinetics of the mixture of biomass fly ash and calcium hydroxide. The biomass fly ash in the investigation comes from cofired (herbaceous with coal) fly ash, which includes different kinds of coal and biomass. All the results show that biomass fly ash with cofiring concentration within the interest to commercial coal–biomass cofiring operations at power plants have equal or much better performances than those of coal fly ash; therefore, the exclusion of biomass fly ash in concrete by ASTM C 618 seems inappropriate and more quality research on the applicability of biomass fly ash in concrete should be conducted.
Contribution of excited hydrogen atoms to charge-exchange excitation of impurities in fusion plasmas

Cross sections are calculated for charge transfer into excited states of ${\mathrm{C}}^{5+}$ and ${\mathrm{O}}^{7+}$ from collisions of ${\mathrm{C}}^{6+}$ and ${\mathrm{O}}^{8+}$ with hydrogen atoms in the n=2 and 3 levels. Effective emission cross sections that account for cascading are then derived for spectral lines emitted when the product ions decay. These are compared to the emission cross sections calculated for excitation by ground-state hydrogen. It is shown that in some circumstances the contribution from excited hydrogen atoms must be taken into account when visible lines are used to determine the oxygen or carbon density from charge-exchange spectroscopy in plasmas. Influences on Lyman-series spectra in the x-ray region are also discussed.
Do Health Insurance and Residence Pattern the Likelihood of Tubal Sterilization among American Women

American women have increasingly opted for tubal sterilization or tubal ligation surgery in recent decades. While research has begun to examine the unequal access to health care in the United States, little research has considered how this may impact whether women opt for a tubal ligation surgery. We first profile women with and without tubal ligations using bivariate analysis of the most recent data available, a nationally representative sample of 7,643 women from the National Survey of Family Growth, Cycle 6 (NSFG, Public use data file, 2002). We then use logistic regression models to examine the relationship between having tubal ligation and two focal variables: (1) type of health insurance (Medicaid compared with private, government or military, and no health insurance), and (2) rural or urban place of residence. We find that women on Medicaid are nearly twice as likely to have had a tubal sterilization compared with women who have private health insurance coverage. Also, women on Medicaid are substantially more likely to have a tubal sterilization than women with government or military insurance and women with no health insurance (26% and 36%, respectively). Further, we find that women living in rural areas are nearly twice as likely to have a tubal sterilization, compared with women in urban or suburban areas, all else being equal.
Neyman Pearson detection of K-distributed random variables

ABSTRACT In this paper a new detection method for sonar imagery is developed in K -distributed background clutter.The equation for the log-likelihood is derived and compared to the corresponding counterparts derived for theGaussian and Rayleigh assumptions. Test results of the proposed method on a data set of synthetic underwatersonar images is also presented. This database contains images with targets of die rent shapes inserted intobackgrounds generated using a correlated K -distributed model. Results illustrating the eectiveness of the K -distributed detector are presented in terms of probability of detection, false alarm, and correct classication ratesfor various bottom clutter scenarios.Keywords: K -distributed clutter, non-Gaussian signal detection, sonar imagery, target detection and classi-cation 1. INTRODUCTION The problem of underwater object detection and classication in sonar imagery has attracted a substantialamount of attention. 1 6 This problem is complicated due to various factors such as variations in operating andenvironmental conditions, presence of spatially varying clutter, variations in target shapes, compositions andorientation. Moreover, bottom features such as coral reefs, sand formations, and vegetation may totally obscurea target or confuse the detection process. Consequently, a robust detection system should be able to quantifychanges between the returns from the bottom and any target activity in sonar images, while at the same timeextract useful features for subsequent classication. Thus, a robust system designed to mitigate false alarms invarious clutter density scenarios will be desirable.Considerable research has been devoted to the develo pment of dierent detector and classication method-ologies to detect and classify underwater objects from sonar imagery. Dobeck
Disk Refining and Ultrasonication Treated Sugarcane Bagasse Residues for Poly(Vinyl Alcohol) Bio-composites

Disk refining and ultrasonication treated sugarcane bagasse residues reclaimed from the waste stream of a simplified bioethanol process after fermentation were used to fabricate biobased composites with poly(vinyl alcohol) (PVA) by film casting. The morphologies and the size distributions of residue particles were characterized by scanning electronic microscopy and various particle size analyzers. The results showed that the residue particle sizes were about hundreds nanometers to tens microns after disk refining treatment. After further treatment by ultrasonication, the particle sizes ranged from about tens of nanometers to several microns. The treated residues were expected to have a large surface area to reinforce PVA. The results indicated that the addition of treated fermentation residues significantly increased the tensile modulus of neat PVA with minimal impact on tensile strength. Furthermore, the PVA composites had higher thermal degradation temperature compared to neat PVA.
Building out a measurement model to incorporate complexities of testing in the language domain

This paper provides a summary of a novel and integrated way to think about the item response models (most often used in measurement applications in social science areas such as psychology, educatio...
Is Arbitration Habit Forming? The Narcotic Effect of Arbitration Use

This paper explores the existence of structural state dependence in arbitration use where it is legally mandated to resolve labor–management bargaining disputes. Previous studies have found both positive state dependence (the narcotic effect) and negative state dependence. This paper reports a negative state dependence for the Minnesota public sector during the period 1973 to 1980. A weak positive trend in arbitration probabilities and a positive relationship between current arbitration probabilities and the proportion of bargainers engaging in arbitration during the same calendar year are also found. An analysis of the dynamic implications of these findings does not support fears that compulsory arbitration schemes are unstable or lead to arbitration as the dominant settlement mode.
Identifying core principles and expectations

I'd like to add my brief response to your discussion about research questions facing our discipline. I can immediately name two.
Manipulation of endogenous regulatory elements and transgenic analyses of the Tbx1 gene

Pharyngeal morphogenesis is a complex process involving precise coordination of multiple cell types and transcription networks. TBX1 heterozygous mutation causes DiGeorge Syndrome, a typical disorder of pharyngeal development. In mice, loss of function of Tbx1 causes severe disruption of pharyngeal development. Therefore, to understand the regulatory circuits controlling the pharyngeal apparatus, it is important to understand how Tbx1 is regulated. Transgenic experiments had shown that a Forkhead (Fox) transcription factor binding site is required for the activity of a Tbx1 enhancer driving expression in many of the endogenous domains. In this study we carried out manipulation of regulatory elements of the endogenous gene in mice and extensive transgenic analysis of the Tbx1 locus. Results indicated that the Fox binding site is dispensable for Tbx1 gene expression, but the enhancer within which it is located regulates, to a limited extent, mesodermal expression of the gene. Transgenic analysis of conserved noncoding regions within 54 kb of the Tbx1 locus identified a novel pharyngeal endoderm-specific enhancer and an intronic suppressor element. Overall, our data suggest a regulatory architecture of the Tbx1 gene made of tissue-specific modules and redundant elements that individually contribute, to a modest extent, to the expression of the gene.
An Analytical Method for Computing the Instant Centers, Centrodes, Inflection Circles, and Centers of Curvature of the Centrodes by Successively Grounding Each Link

An analytical method is presented for determining the instant centers, centrodes, inflection circles, and centers of curvature of the centrodes of a mechanism. The method uses the vector loop and kinematic coefficient concepts and is applicable to any mechanism which can be represented by vector loops. A modified vector loop approach includes the idea of mechanism inversion to obtain relative kinematic coefficients, thus eliminating the need for recalculating them. A computer program was written incorporating the method, and examples are given.
Chatter Frequency in Turning Considering Tool Compliance and Wearland

An analytical model for the chatter frequency of a turning cutter considering system compliance and flank wear of the tool is presented in this research. The fundamental mechanism of self-excited vibration at the presence of tool wearland is examined, and a mathematical model is developed to describe the frequency characteristics of the vibration. In the paper a comparison of the chatter frequencies for a fresh cutting tool and a worn cutting tool is provided to demonstrate the coupling between wearland and chatter. The theoretical model of chatter frequency is validated by experimental observations over a range of turning conditions.
Recursive validation and clustering for distributed spectrum sensing in CR-MANET

In cognitive radio networks, secondary users need to accurately identify primary user spectrum occupancy in order to use it. Accurate spectrum sensing is hindered by signal fading, hidden terminal problems, byzantine failures, etc. Centralized cooperative spectrum sensing works well if the secondary user network is infrastructure based and there is a centralized basestation making network wide decisions. When the secondary users network is a cognitive radio mobile ad-hoc network (CR-MANET), then decisions need to be made in a distributed manner and cooperative spectrum sensing introduces additional problems due to the presence of malicious users. These malicious secondary users encourage other secondary users to make a wrong spectrum occupancy decision by feeding inaccurate measurements. We study this problem and present a solution to improve primary user spectrum occupancy identification accuracy in the presence of malicious users. A virtual neighbor cluster is created in which the mobile device forms an evolving cluster of past neighbor devices that aids in validating the input gathered from the current neighboring devices. Next, a recursive partitioning around medoids based clustering is performed to identify a tightly bound set of valid inputs. The validated inputs from both the methods form a decision cluster and the data is fused to get the decision on primary user occupancy. Two data fusion strategies are presented and their use depends on the amount of dynamism in the CR-MANET. The analysis and results show the accuracy of primary user occupancy detection even in the presence of large number of malicious users and signal measurement errors.
Incidence and clinical significance of sigmoidoceles as determined by a new classification system

PURPOSE: A study was undertaken to assess the incidence and clinical significance of sigmoidocele as a finding during cinedefecography. METHODS: All patients who underwent cinedefecography between July 1988 and July 1992 were prospectively evaluated. Clinical data were assessed by a standardized questionnaire. Sigmoidocele was classified based on the degree of descent of the lowest portion of the sigmoid: 1° = above the pubococcygeal line; 2° = below the pubococcygeal line and above the ischiococcygeal line; 3° = below the ischiococcygeal line. This classification was then correlated with the patient's symptoms and percentage of redundancy relative to rectal length. RESULTS: Twenty-four sigmoidoceles (5.2 percent) were noted in 463 cinedefecographic studies; 289 of these patients had constipation. These five males and 19 females were of a mean age of 57 (range, 20–77) years. Nine patients had 1° sigmoidocele, seven had 2°, and eight had 3°. Percentage of sigmoid redundancy was 51 percent, 65 percent, and 88 percent for 1°, 2°, and 3°, respectively (P=0.0001). Impaired rectal emptying was present in 16 patients (67 percent). Five of eight patients with 3° sigmoidocele underwent colonic resection with or without rectopexy. The other three patients were conservatively managed. One of seven patients with 2° sigmoidocele underwent colectomy, and the other six were conservatively managed as were all nine patients with 1°. Posttreatment improvement was noted in 100 percent (6 of 6) of patients operated on but in only 33 percent (6 of 18) of patients conservatively treated. Thus, this proposed classification system yielded excellent correlation among the mean of level of the sigmoidocele, percentage of redundancy, and clinical symptoms. Furthermore, clinical significance of 3° sigmoidocele is supported by the fact that all five of 3° patients who underwent colonic resection reported symptomatic improvement at a mean follow-up of 23 (range, 15–39) months. CONCLUSION: Sigmoidocele may account for symptoms of obstructed defecation, and, therefore, it must be considered in the differential diagnosis and evaluation of constipation. Staging of sigmoidocele is useful in determining both clinical significance and optimal treatment.
Analysis of Standard Operating Procedures for Enhanced Regional Transportation Systems Operations

Traditionally, transportation system operations have been constrained by jurisdictional and administrative boundaries. Local governments and state agencies have operated facilities for which they are responsible with little coordination. As surface transportation mobility challenges continue to increase, it is evident that although different localities and agencies may still operate their own systems, there is a need for coordinated regional operations. An important component of enabling such coordination is the achievement of consistency in the standard operating procedures (SOPs) used by the individual transportation operations centers (TOCs). Historically, each TOC has developed its own SOPs, suited to its own unique needs and the resources available. Although these individual SOPs have served their TOCs well, such customized operations procedures of a TOC are often not compatible with its neighboring TOCs. As such, establishing regional coordination, especially to manage large-scale incidents or emergencies, is difficult. In this research effort a methodology was developed to analyze TOC SOPs to find opportunities to increase regional consistency. This methodology was applied in a case study to analyze the SOPs of the five TOCs and the statewide emergency operations center in the state of Virginia. The results of this study indicate that several differences indeed hamper coordination among the centers. At the same time a number of procedures with the potential for increased consistency are also identified. Information contained in this paper will benefit systems integrators, planners, researchers, and other transportation professionals involved in regional integration efforts and in policy and procedures review.
The Critical Pitch-Thickness Relation at the Cholesteric-Nematic Phase Transition by the Optical Mass Transport Method

Abstract The optical mass transport (OMT) method was utilized to study the cholesteric pitch as a function of thickness at the cholesteric-nematic phase transition in a wedge-type diffusion cell at two different geometries. We obtained a linear relation between the cholesteric finger print pitch (Pc) and the film thickness (Lc) at the critical cholesteric-nematic boundary layer. The measurements were done by direct observation via an optical microscope. Due to the presence of the concentration gradient, the surface anchoring is weakened and large pitch values within the range of Lc/Pc ≤ 0.15 were established. The thickness gradient as well as the concentration gradient showed systematic linear effects on the data. We found a qualitative agreement between the present experimental data and that of a previous theory.
Laser-based obstacle detection and avoidance system

The Center for Self-Organizing and Intelligent Systems at Utah State University has been developing laser-based obstacle detection and avoidance during the past four years. The JPL initially encouraged us down this path to provide an optional software upgrade for its Rocky Rover. The USU system was based on a unique combination of fuzzy logic and a decision tree behavioral technique, and this system provided the Rocky Rover the option of venturing independently beyond the observance of the base station. Shortcomings in the data collection prompted a redesign that included more sophisticated line tracing and filtering methods to locate and track the actual laser lines. The signal to noise ratio problems combined with platform changes lead to the choice of a commercial range finder. The design challenge then became one of system integration including the meting of real time constraints on the current processor platform, and obstacle characterization and avoidance.
An Update of Congenital Adrenal Hyperplasia

Publisher Summary Congenital adrenal hyperplasia (CAH) is a family of disorders of adrenal steroidogenesis resulting from an inherited deficiency of one of several enzymes necessary for normal steroid synthesis. This chapter describes the recent advances in congenital adrenal hyperplasia. These advances have come from the interdisciplinary collaboration of embryologists, teratologists, enzymologists, immunogeneticists, population geneticists, steroid endocrinologists, and gender psychologists. The chapter describes asimplified scheme of adrenal steroidogenesis. It provides an overview of the additional evidence that supports the concept that the adrenal fasciculate and glomerulosa function as two separate glands. This has been gained from the recent study of patients with 21-hydroxylase deficiency. New data shows that in CAH, there is a 21-hydroxylation defect in the zona fasciculata of simple virilizers and salt wasters, whereas zona glomerulosa is defective in salt wasters and not in simple virilizers. The data suggest that there is one enzyme involved in the 21-hydroxylation of the 17-hydroxy and 17-deoxy pathways of adrenal steroidogenesis in zona fasciculata.
THE DILUTED STOICHIOMETRIC OXIDATION OF ISO-OCTANE IN THE INTERMEDIATE TEMPERATURE REGIME AT ELEVATED PRESSURES

Experimental and modeling results for dilute stoichiometric oxidation of iso-octane in the intermediate temperature regime are presented for pressures of 6 and 9 atmospheres. While the overall comparison between the experiments and modeling is acceptable, important differences exist in the predictions of the mole fractions of acetone and methacrolein, which are products of iso-butene oxidation. The results from this study arc compared to earlier work on the oxidation iso-octane under very lean conditions to illustrate the significance of chemical pathways in which molecular oxygen is a key reaclant.
The current status of the mechanism of the calcium channel antagonists.

Abstract This short review has not detailed all the experimental data that have suggested the efficacy of the calcium channel antagonists in various ischemic and ischemic-related events, nor has it listed their chemical structures. Such information is readily available in the published literature. The sole purpose of this review was to answer one fundamental question. What is the basic mechanism of action of this class of drugs? The answer obviously is unavailable. It is conceded that this broad class of drugs does inhibit transmembrane Ca ++ flux. In order to assign this function as their basic mechanism of action, however, other potential areas must be excluded. The discussion presented in this review has indicated that to date, such has not been accomplished. In cardiac muscle, it has been suggested that the calcium channel antagonists may well affect positive inotropy in certain cases, and that the specific events whereby calcium moves into the myocardial cell during ischemia have not been delineated. It has not been demonstrated how much Ca ++ influx should be inhibited in order to achieve a beneficial effect on the course of ischemia. With respect to vascular smooth muscle, the basic fundamental calcium-regulating mechanisms have not yet been delineated, and heterogeneity of tissue responsiveness to these and other drugs has also been demonstrated. As a result, one cannot assign a specific mechanism of action underlying the effect of calcium channel antagonists on relaxation of these vascular tissues. The whole question of platelet involvement in ischemia and the role of calcium in platelet aggregation should be examined before these blood components can be eliminated as a potential source of drug effect. The suggestion of calcium channel blockade as a mechanism of action is a rational explanation for much of the end data presented in the past, i.e., vasodilatation and decreased inotropy. However, other potential sites of action have not yet been eliminated, and additional work must be done before the specific site or sites can be positively identified. This review should in no way compromise the exciting clinical manifestations of these new drugs. They do show considerable promise in this regard, but caution should be used in designating these positive effects as occurring solely by calcium channel inhibition.
Effect of subacute dietary nitrate on production traits and plasma analytes in Suffolk ewes

Elevated dietary nitrate (NO3-) is associated with production losses in ruminant livestock, resulting in substantial economic losses incurred by producers. Severe drought, fertilization practices and poorly maintained pastures increase the risk of elevated NO3- intake among cattle and sheep. Nitrate is metabolized to nitrite (NO2-) in the rumen and further reduced to ammonia. Ruminants consuming high dietary NO3- vary in ability to efficiently reduce excess NO2- to ammonia. This leads to methemoglobin formation and ultimately NO3- toxicity signs. Variation in individual tolerance to elevated dietary NO3- can be partially attributed to rate and duration of exposure, rate of elimination, metabolism, species and dose. Our objectives were to confirm and quantify variation in individual tolerance to subacute levels of dietary NO3-, and determine if individuals could be identified as highly or lowly tolerant to elevated dietary NO3- based on production traits, plasma analytes and(or) signs of subacute NO3- toxicity. Purebred Suffolk ewes were administered supplement mixed with tap water (control; n = 8) or potassium nitrate (NO3- treated; 300 mg NO3-/kg BW daily; n = 47) for 8 days. Coefficients of variation (CV) indicated that supplement intake was more variable in NO3- treated ewes (CV = 59.3%) than in control ewes (CV = 13.6%). Among NO3- treated ewes, six ewes highly tolerant and six ewes lowly tolerant to elevated dietary NO3- were identified based on individual performance, NO3- treated supplement intake, and signs of toxicity. Supplement intake was lower (P < 0.0001) in NO3- treated ewes than in control ewes, indicating elevated dietary NO3- influences feed intake. Supplement intake differed (P < 0.0001) between control, highly tolerant and lowly tolerant ewes. Supplement intake of highly and lowly tolerant ewes was 82% and 23%, respectively, of the control ewes' intake. Weight change and plasma concentrations of NO2-, cortisol, glucose and retinol were not different (P 0.38) among control, highly tolerant and lowly tolerant ewes. Plasma urea nitrogen (PUN) levels were not different (P = 0.25) between control and lowly tolerant ewes, but were lower (P = 0.02) in highly tolerant ewes than in control ewes. Furthermore, PUN and NO3- treated supplement intake were highly correlated (0.71; P < 0.0001) in lowly tolerant ewes. These results confirm and quantify variation in response to subacute levels of dietary NO3- and indicate that individuals can be identified as highly or lowly tolerant to elevated dietary NO3- based on their performance and NO3- toxicity signs.
Focal Plane Instrumentation for the Wide-Field X-ray Telescope

The three X-ray imaging focal planes of the Wide-Field X-ray Telescope (WFXT) Mission will each have a field of view up to 1 degree square, pixel pitch smaller than 1 arcsec, excellent X-ray detection efficiency and spectral resolving power near the theoretical limit for silicon over the 0.2 - 6 keV spectral band. We describe the baseline concept for the WFXT focal planes. The detectors are derived from MIT Lincoln Laboratory CCDs currently operating in orbit on Chandra and Suzaku. Here we describe the baseline WFXT focal plane instrumentation and briefly consider options for alternative detector technologies.
Beyond Black and White: New Faces and Voices in U.S. Schools

Beyond Black and White: New Faces and Voices in U.S. Schools. Maxine Seller and Lois Weis, eds. Albany: State University of New York Press, 1997. 328 pp.
AN EXPERIMENTAL STUDY OF SPHERICAL INDENTATION ON PIEZOELECTRIC MATERIALS

The response of lead zirconate titanate and barium titanate piezoelectric ceramics to spherical microindentation was investigated. Force vs penetration depth curves obtained from instrumented indentation reveal that the indentation stiffness depends on the material condition (i.e. poled vs unpoled) and the type of indentor (i.e. electrically conducting vs insulating). Good agreement was found between the experimental results and predictions of an analytical model of Giannakopoulos and Suresh (1999) for the spherical indentation of a transversely isotropic piezoelectric material. A parametric analysis was conducted to identify key material properties that influence the indentation response. An error analysis was performed so as to assess the influence of the variabilities in constituent properties on the scatter in the measured indentation stiffness. This indentation method has been shown to offer a new methodology for characterizing some properties of piezoelectric materials. Advantages and limitations of such a technique are discussed.
The effect of tropospheric layer structures on long-range VHF radio propagation

Long-distance radio communication at VHF is investigated by the waveguide mode theory taking into account the strong gradient, layered structure of the troposphere. A linear-segmented numerical method for the squared refractive index profile is developed to calculate the wave modes. This method reduces the reflection error from the discontinuities that occur in the conventional step-function approximation. The frequency at which only one mode is reasonably well trapped is used to determine the lowest usable frequency for tropospheric communication. It is found that such communication is possible at almost all VHF frequencies when the refractive index contrast ( \Delta n ) is greater than 40N units. However, if \Delta n is reduced to 10N units or less, the troposphere is almost transparent for VHF radio signals. The received field in terms of the field in free space is calculated for antennas located either above or below the layer. It is shown that various long-distance radio observations can be explained by whispering-gallery modes in the troposphere.
Designating Opponents in Empirical Research Reports: The Rhetoric of ‘Interestingness’ in Consumer Research

Numerous studies have called attention to the importance of rhetoric inscientific writing by focusing on arguments presented in scientific debate articles. In contrast, citation analysis studies indicate that empirical research articles are generally nonconfrontational in criticizing the work of other researchers. How do empirical research reports establish opposing perspectives to argue against? One rhetoricalstrategy is to be ‘interesting’, which, according to Davis (1971), is the author’s attempt to contradict a taken-for-granted assumption of the reader. Scholars in management, marketing, and consumer research have also cited Davis’ conception of ‘interestingness’ as a characteristic of research that is more influential and intellectually creative. This article presents textual evidence from a volume of the Journal of Consumer Research demonstrating that a majority of researcher-authors of these articles use ‘interestingness’ as a rhetorical framing device in the abstracts, introductions, and concludi...
Mechanism Responsible for T-Cell Antigen Receptor- and CD28- or Interleukin 1 (IL-1) Receptor-Initiated Regulation of IL-2 Gene Expression by NF-κB

Initiation of the T-helper lymphocyte activation program is regulated through the T-cell receptor (TCR) and costimulatory receptors. Analysis of TCR and either anti-CD28- or interleukin 1 (IL-1)-mediated activation of the IL-2 promoter shows that costimulatory signals augment promoter activity through NF-κB sites. This study comparatively evaluates the mechanisms whereby signals initiated from the TCR and these two costimulatory receptors converge to synergistically increase NF-κB transcriptional activity. IL-1 alone stimulates an acute but transient NF-κB nuclear localization and a suboptimal NF-κB transcriptional response. In contrast, anti-CD3–anti-CD28 or anti-CD3–IL-1 synergistically stimulate prolonged NF-κB nuclear localization and NF-κB-mediated transcription. Both TCR- and costimulatory receptor-initiated synergistic NF-κB responses result from prolonging high rates of cytosolic IκB degradation during the second phase of the biphasic NF-κB nuclear localization. However, in contrast to previous reports, prolonged nuclear localization of NF-κB complexes is not necessarily associated with long-term depletion of IκBβ. In response to either costimulus, c-Rel selectively translocated to the nucleus as a result of induced c-Rel expression and the continued production of c-Rel–IκBα complexes, which turn over rapidly due to the high rate of IκBα degradation in the cytosol during the second phase of the response. In contrast, IκBβ is nearly completely degraded during the acute response to either IL-1 or anti-CD3–IL-1 while anti-CD3–anti-CD28 stimulates only a partial reduction (35 to 40%) in cytosolic IκBβ. Cyclosporine (CsA), which inhibits stimulus-induced NF-κB transcriptional activity, selectively inhibits the stimulus-induced c-Rel nuclear localization and the rapid formation and degradation of c-Rel–IκBα complexes in the cytosol. CsA also inhibits both the prolonged, high rate of IκBα degradation and the lower level of IκBβ turnover during the second phase of the activation response. Together, these results suggest a mechanism by which signals from the T-cell antigen receptor and either CD28 or IL-1 synergistically regulate IL-2 gene transcription by modulating NF-κB nuclear translocation.
Facilitating and Undermining Organizational Change A Case Study

This article offers a case study of a research-action project in which the author functioned as researcher and change agent. The success and failure of this project was related to his finding and losing the balance of joining and remaining separate from a social system's dynamics. The author describes the research project and reflects on its covert dynamics. In doing so, he illustrates the relationship between helping system members get unstuck from their automatic, dysfunctional patterns of relationships and getting himself unstuck from those patterns. He describes as well the forces within him and in the system itself that pulled for him to lose his balance, such that he either tumbled into it as a member or fell away from it altogether. He frames the earnings in terms of change agents creating or undermining the holding environment in which system members struggle to change dysfunctional relationship patterns.
Respirable particles and carcinogens in the air of delaware hospitality venues before and after a smoking ban.

How do the concentrations of indoor air pollutants known to increase risk of respiratory disease, cancer, heart disease, and stroke change after a smoke-free workplace law? Real-time measurements were made of respirable particle (RSP) air pollution and particulate polycyclic aromatic hydrocarbons (PPAH), in a casino, six bars, and a pool hall before and after a smoking ban. Secondhand smoke contributed 90% to 95% of the RSP air pollution during smoking, and 85% to 95% of the carcinogenic PPAH, greatly exceeding levels of these contaminants encountered on major truck highways and polluted city streets. This air-quality survey demonstrates conclusively that the health of hospitality workers and patrons is endangered by tobacco smoke pollution. Smoke-free workplace laws eliminate that hazard and provide health protection impossible to achieve through ventilation or air cleaning. (J Occup Environ Med. 2004;46:887–905)
A rapid response, planar fluorosensor for measuring two-dimensional pCO2 distributions and dynamics in marine sediments

CO 2 distributions in marine sediments are closely coupled to early diagenetic reactions and transport process- es. An existing planar optode designed to measure pCO 2 in sediments and overlying water was modified to sub- stantially lower response times and to allow for enhanced resolution of CO 2 dynamics. Sensing foils are fabricat- ed by entrapping fluorescent indicator 8-hydroxy-1,3,6-pyrenetrisulfonic acid-tetraoctylammonium ion-pair (TOA + PTS 4- , molar ratio 1:1) and tetraoctylammonium hydroxide (TOAOH) in a hydrophobic ethyl cellulose polymer matrix on an inert transparent polyester support, and coated with gas permeable silicone membrane. The response time of the optimized sensor is 18 s (0 AE 5 matm), allowing measurement of transient pCO 2 dis- tributions associated with microenvironments such as burrows. As typically configured, the ratiometric sensor has a working range of 0 to ~40 matm pCO 2 and a detection limit of 0.193 matm (3s), and shows fluorescence emission at 515 nm with dual excitation at 470 and 407 nm, and a well-defined isosbestic point. The sensor is sensitive, precise, stable, and reversible, and retains its properties after continuous exposure in marine sediments for approximately 2 weeks at 15°C, with a longer or shorter lifetime at lower or higher temperatures respective- ly. This sensor has been successfully used to measure two-dimensional pCO 2 distributions and dynamics in marine sediments and overlying water with a typical pixel resolution of ~ 50¥50 µm over an area of ~150 cm 2 .
Optimal control computation by the Newton-Raphson method and the Riccati transformation

A computational procedure is described for finding extremal control policies for nonlinear processes. The control problem is formulated as the problem of Bolza in the classical calculus of variations. The method is iterative in nature and prescribes a successive linearization of the Euler-Lagrange equations to obtain the extremal control. The resulting sequence of linear problems is solved such that the successive solutions may, in some well-defined manner, converge to the extremal solution. The linear two-point boundary value problem is decoupled by means of a generalized Riccati transformation. First, the matrix Riccati equation is integrated backwards in time. Then the state equations can be integrated forwards in time. The resulting curves can then be used for the next iteration. It is pointed out that in some instances the method yields a linear feedback control law, which is optimal with respect to initial condition perturbations. Also, the method allows for a sufficieney check. At the termination of the iterations, Jacobi's condition and the strengthened Legendre condition can be checked to see whether or not the control obtained is indeed optimal in the sense of a weak local minimum. Numerical results are presented and a brief comparison is made between this method and the First and Second Variation methods.
Determinants of bone density in young women. I. Relationships among pubertal development, total body bone mass, and total body bone density in premenarchal females.

Bone mass accretion during puberty appears to be critical in the development of peak bone mass, which, in turn, is believed to be a major determinant of osteoporosis risk. Although genetics may be the primary determinant of peak bone mass, modifiable secondary factors, such as nutrition and hormone exposure, may significantly affect bone mass accretion during the second decade of life. As part of a longitudinal study of major determinants of bone development during puberty, we obtained cross-sectional measurements from 112 premenarchal caucasian females (mean +/- SD age, 11.9 +/- 0.49 yr at study entry). Total body bone mineral density (TBBMD) and total body bone mineral content (TBBMC) were measured by dual energy x-ray absorptiometry and compared to anthropometric, pubertal development, urinary steroid and gonadotropin levels, and nutrient intake. An integrated estrogen exposure index was developed and used to evaluate the cumulative effect of circulating estrogen levels on both development. Compared to...
A Procedure for Optimizing the Design of Scrainjet Engines

Although the concept of using a supersonic combustion ramjet engine to propel a vehicle at hypersonic speeds through the atmosphere has been thoroughly established over the past two decades, and analyses for determining the performance of each of its components documented, no complete engine cycle analysis has been presented to date. The purpose of this paper is to review and discuss the individual component analyses previously developed, combine them into a unified cycle analysis, and present the methodology needed to optimize the design of a scramjet engine using the unified cycle analysis. A specific example applying this optimization procedure to a missile design is also included.