cssi/SciSciGPT-SciSciNet huggingface dataset:
INVESTIGATION OF SHELL DISEASE IN MAP TURTLES (GRAPTEMYS SPP.)

Nineteen map turtles (Graptemys spp.) maintained under natural conditions were investigated because of chronic shell abnormalities. Animals were evaluated using a novel shell scoring system that divided the 54 scutes into six regions, with each region scored for lesion extent and severity, and summated to produce a total shell disease score (TSDS). Complete blood counts and various biochemistry analytes (total protein, albumin, globulin, urea, uric acid, 25-hydroxycholecalciferol, phosphorus, and ionized and total calcium) were measured. Under ketamine-medetomidine-morphine anesthesia, cytology tape strips and full thickness shell biopsies were collected aseptically for microbiologic, histologic (including scoring of biopsy quality), and ultrastructural evaluations. The TSDSs were low and ranged from 4 to 22 (median=9) out of a possible score of 54. There were no correlations between TSDS and any hematologic or biochemistry parameter. The histologic quality of shell biopsies was good, and normal shell str...
Trajectories of probe spheres in generalized linear viscoelastic complex fluids

We have developed a fast simulation that generates a random walk of an isolated probe sphere in a generalized linear viscoelastic complex fluid over a highly extended dynamic range. We introduce a coupled harmonically bound Brownian particle (c-HBBP) model, in which the relaxation modes of the viscoelastic medium are treated as harmonic wells. These wells are coupled to the probe sphere and perform Brownian motion in bound harmonic potentials corresponding to the next-longer relaxation mode, according to the relaxation spectrum of the viscoelastic material. We implement this c-HBBP model by generating variable temporal step sizes that have a uniform distribution in logarithmic time. We create and analyze trajectories for several different viscoelastic complex fluids: a polymer system at its gel point, a dense emulsion system, a blend of two monodisperse polystyrene polymers for which the relaxation spectrum has been measured, and a model anisotropic soft system that shows dense emulsion-like and gel-point behaviors along two orthogonal directions. Except for unusual viscoelastic materials, such as the polymer system at its gel point, the generated trajectories are neither self-similar nor self-affine. The resulting mean square displacements predicted by the c-HBBP model are consistent with the single-particle generalized Stokes–Einstein relation of linear passive microrheology.
Quadrupole Coupling and Knight Shift Anisotropy in "hcp" Lanthanum

The nuclear magnetic resonance of ${\mathrm{La}}^{139}$ has been observed in hcp polycrystalline lanthanum metal at 25.6 kOe and 300\ifmmode^\circ\else\textdegree\fi{}K. The recorded pattern at 15.5 Mc/sec displays a central line and one pair of satellite lines. The position and shape of the central line yields an isotropic Knight shift of (0.685\ifmmode\pm\else\textpm\fi{}0.020)% and an axial shift of (0.046\ifmmode\pm\else\textpm\fi{}0.020)%. The satellite spacing yields a lowest pure quadrupole frequency ${\ensuremath{\nu}}_{Q}=101\ifmmode\pm\else\textpm\fi{}4$ kc/sec or $\frac{{e}^{2}\mathrm{qQ}}{h}=(1.41\ifmmode\pm\else\textpm\fi{}0.06)$ Mc/sec. A calculation of the lattice electric field gradient is made for the $\mathrm{ABAC}$ stacking sequences, yielding 0.540\ifmmode\times\else\texttimes\fi{}${10}^{22}$ and 0.487\ifmmode\times\else\texttimes\fi{}${10}^{22}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ for the so-called $A$ and $B$ (or $C$) layer sites, respectively, by the method of plane-wise summation of de Wette. Improved values of the nuclear electric quadrupole moment, $Q({\mathrm{La}}^{139})=0.21$ b, and the Sternheimer antishielding factor, ${\ensuremath{\gamma}}_{\ensuremath{\infty}}({\mathrm{La}}^{3+})=\ensuremath{-}73.5$, are adopted and discussed. The sign of the conduction-electron electric field gradient is shown to be negative.
Linearly implicit methods for nonlinear PDEs with linear dispersion and dissipation

The linear stability of IMEX (IMplicit-EXplicit) methods and exponential integrators for stiff systems of ODEs arising in the discrete solution of PDEs is examined for nonlinear PDEs with both linear dispersion and dissipation, and a clear method of visualization of the linear stability regions is proposed. Predictions are made based on these visualizations and are supported by a series of experiments on five PDEs including quasigeostrophic equations and stratified Boussinesq equations. The experiments, involving 24 IMEX and exponential methods of third and fourth order, confirm the predictions of the linear stability analysis, that the methods are typically limited by small eigenvalues of the linear term and by eigenvalues on or near the imaginary axis rather than by large eigenvalues near the negative real axis. The experiments also demonstrate that IMEX methods achieve comparable stability to exponential methods, and that exponential methods are significantly more accurate only when the problem is nearly linear. Novel IMEX predictor-corrector methods are also derived.
Locations, Outcomes, and Selective Migration

Studies attempting to link locational attributes and individual outcomes often focus on children or young adults, under the presumption that their location was exogenously determined by their parents. This strategy is more difficult to justify if parents migrate selectively and tend to transmit their own characteristics to their children. This paper uses Census microdata to document a strong link between selective migration in one generation and economic outcomes in the next. I show that selective migration is a possible explanation for a puzzle in the existing literature: the changing relationship between segregation levels and individual outcomes within the black population.
SU-E-I-28: Development of Graphic Patient Models for a Real-Time Skin Dose Tracking System (DTS) for Fluoroscopic Interventional Procedures.

Purpose: To develop a library of graphic human models that closely match patients undergoing interventional fluoroscopic procedures in order to obtain an accurate estimate of their skin dose. Methods: A dose tracking system (DTS) has been developed that calculates the dose to the patient's skin in real time during fluoroscopic procedures based on a graphical simulation of the x‐ray system and the patient. The calculation is performed using a lookup table containing values of mGy per mAs at a reference point and inverse‐square correction using the distance from the source to individual points on the skin. For proper inverse‐square correction, the external shape of the graphic should closely match that of the patient. We are in the process of developing a library of 3D human graphic models categorized as a function of basic body type, sex, height and weight. Two different open‐ source software applications are being used to develop graphic models with varying weights and heights, to ‘morph’ the shapes for body type and to ‘pose’ them for proper positioning on the table. The DTS software is being designed such that the most appropriate body graphic can be automatically selected based on input of several basic patient dimensional metrics. Results: A series of male and female body graphic models have been developed which vary in weight and height. Matching pairs have been constructed with arms at the side and over the head to simulate the usual placement in cardiac procedures. The error in skin dose calculation due to inverse‐square correction is expected to be below 5% if the graphic can match the position of the patient's skin surface within 1 cm. Conclusions: A library of categorized body shapes should allow close matching of the graphic to the patient shape allowing more accurate determination of skin dose with the DTS. Support for this work was provided in part by NIH grants R43FD0158401, R44FD0158402, R01EB002873 and R01EB008425, and by Toshiba Medical Systems Corporation.
Environmental contributions to allergic disease

The environment is a major contributor to allergic disease, and great effort is being expended to identify the chemical pollutants and allergens that make a significant impact. Exposure to high levels of ozone, sulfur dioxide, nitrogen dioxide, and diesel exhaust particles is known to reduce lung function. Studies continue to delineate the role of these particles as adjuvants and carriers of allergens into the respiratory system. Current studies also show the exacerbation of allergic disease through fungal spore inhalation and continue to document the role of pollen in allergic rhinitis. Pollen also was recently associated with asthma epidemics, especially after thunderstorms. Forecasting models currently are being developed that predict the trajectories of pollen dispersal and may allow increased avoidance of dangerous outdoor conditions.
Automated induction of sense in context

In this paper, we introduce a model for sense assignment which relies on assigning senses to the contexts within which words appear, rather than to the words themselves. We argue that word senses as such are not directly encoded in the lexicon of the language. Rather, each word is associated with one or more stereotypical syntagmatic patterns, which we call selection contexts. Each selection context is associated with a meaning, which can be expressed in any of various formal or computational manifestations. We present a formalism for encoding contexts that help to determine the semantic contribution of a word in an utterance. Further, we develop a methodology through which such stereotypical contexts for words and phrases can be identified from very large corpora, and subsequently structured in a selection context dictionary, encoding both stereotypical syntactic and semantic information. We present some preliminary results.
Microorganisms as tracers in groundwater injection and recovery experiments: a review

Modern day injection and recovery techniques designed to examine the transport behavior of microorganisms in groundwater have evolved from experiments conducted in the late 1800s, in which bacteria that form red or yellow pigments were used to trace flow paths through karst and fractured-rock aquifers. A number of subsequent groundwater hydrology studies employed bacteriophage that can be injected into aquifers at very high concentrations (e.g., 1013 phage ml−1) and monitored through many log units of dilution to follow groundwater flow paths for great distances, particularly in karst terrain. Starting in the 1930s, microbial indicators of fecal contamination (particularly coliform bacteria and their coliphages) were employed as tracers to determine potential migration of pathogens in groundwater. Several injection and recovery experiments performed in the 1990s employed indigenous groundwater microorganisms (both cultured and uncultured) that are better able to survive under in situ conditions. Better methods for labeling native bacteria (e.g. by stable isotope labeling or inserting genetic markers, such as the ability to cause ice nucleation) are being developed that will not compromise the organisms' viability during the experimental time course.
ON THE COMPUTATION OF UNCERTAINTY MEASURE IN DEMPSTER-SHAFER THEORY

An algorithm for computing the recently proposed measure of uncertainly AU for Dempster-Shafer theory is presented. The correctness of the algorithm is proven. The algorithm is illustrated by simple examples. Some implementation issues are also discussed.
Does functional ability in the postoperative period differ between remifentanil- and fentanyl-based anesthesia?

Abstract Study Objectives: To compare patients' functional ability in the 24-hour postoperative period following a remifentanil compared to a hypnotic-fentanyl-treated anesthesia regimen using a 24-Hour Functional Ability Questionnaire. Design: Prospective, 1:1 single-blind, randomized, controlled effectiveness study. Setting: Multicenter study including 156 hospitals and ambulatory surgery facilities. Patients: 2438 patients (1496 outpatients and 942 inpatients) 18 years of age or older, scheduled for elective surgeries under general endotracheal anesthesia, with an expected duration of unconsciousness of ≥30 minutes. Interventions: Patients were randomized to receive either intravenous remifentanil (0.5 μg/kg/min for induction and intubation; with the infusion rate decreased to 0.25 μg/kg/min after intubation) or fentanyl (administered according to anesthesiologists' usual practice) as the opioid during surgery. Concomitant hypnotic drugs were propofol and/or isoflurane (with or without nitrous oxide) titrated according to protocol. Transition analgesia with either morphine or fentanyl was given in the remifentanil patients and at the discretion of the anesthesiologists in the fentanyl patients. Measurements: A validated set of measurements of functional ability, rather than more traditional clinical psychological methods, to compare the recovery of patients from remifentanil- and fentanyl-treated anesthetic regimens up to 24 hours after surgery. Main Results: Remifentanil was statistically superior to fentanyl for the four functional assessments evaluated: walking without dizziness, thinking clearly, concentration, and communicating effectively. These differences reflect events occurring within the first 24 hours after anesthesia and surgery. Conclusions: A remifentanil-treated anesthetic demonstrated earlier return to some functions than a fentanyl-treated technique. Although functional assessment is a field that is still in its infancy, a questionnaire to assess functional ability during the 24 hours after anesthesia may provide more practical information about anesthetic recovery than previously used, traditional psychomotor evaluations.
Reliability of the dynamic gait index in people with vestibular disorders.

Abstract Wrisley DM, Walker ML, Echternach JL, Strasnick B. Reliability of the Dynamic Gait Index in people with vestibular disorders. Arch Phys Med Rehabil 2003;84:1528–33. Objective To examine the interrater reliability of the Dynamic Gait Index (DGI) when used with patients with vestibular disorders and with previously published instructions. Design Correlational study. Setting Outpatient physical therapy clinic. Participants Subjects included 30 patients (age range, 27–88y) with vestibular disorders, who were referred for vestibular rehabilitation. Interventions Subjects' performance on the DGI was concurrently rated by 2 physical therapists experienced in vestibular rehabilitation to determine interrater reliability. Main outcome measures Percentage agreement, κ statistics, and the ratio of subject variability to total variability were calculated for individual DGI items. Kappa statistics for individual items were averaged to yield a composite κ score of the DGI. Total DGI scores were evaluated for interrater reliability by using the Spearman rank-order correlation coefficient. Results Interrater reliability of individual DGI items varied from poor to excellent based on κ values (κ range, .35–1.00). Composite κ values showed good overall interrater reliability (κ=.64) of total DGI scores. The Spearman ρ demonstrated excellent correlation ( r =.95) between total DGI scores given concurrently by the 2 raters. Conclusion DGI total scores, administered by using the published instructions, showed moderate interrater reliability with subjects with vestibular disorders. The DGI should be used with caution in this population at this time, because of the lack of strong reliability.
High-strain-rate response of ultra-fine-grained copper

The high-strain-rate response of ultra-fine-grained (UFG) copper processed by equal channel angular pressing (ECAP) was characterized by three different dynamic testing methods: reverse Taylor impact, cylindrical compression specimens, and hat-shaped specimens in Hopkinson bar experiments. Upon recovery after impact, the specimens were found to undergo dynamic recrystallization at a calculated temperature of 360 K, indicating that the UFG copper is thermally unstable. Reverse Taylor tests were conducted on as-received oxygen-free high-conductivity copper rod and ECAP specimens with 2 and 8 sequential deformation passes. The dynamic deformation of the samples was modeled using AUTODYN-2D, and a modified Johnson–Cook constitutive equation was found to closely capture the dynamic response. Both the dynamic experiments and analysis from the reverse Taylor tests indicate enhanced strain-rate sensitivity in comparison with conventional polycrystalline copper, in agreement with predictions of reduced activation volume. The shear band thickness, as obtained in forced localization tests, showed a marked decrease, in comparison to conventional polycrystalline copper; this effect is interpreted as due to an accelerated thermal softening and inherent instability exhibited by the UFG structure.
Air classification of peas (Pisum sativum) varying widely in protein content.

Four samples of field peas, ranging in protein content from 14.5–28.5% (dry, dehulled seed basis), were pin milled and air classified yielding protein concentrates and starch concentrates containing 33.6–60.2 and 3.8–11.3% protein, respectively. The protein content of the dehulled peas were negatively correlated with their starch content (49.7–59.8%), lipid content (3.0–4.1%) and cell wall material (CWM) content (7.1–9.6%). The % protein in all air classified fractions was positively correlated to % protein in the dehulled peas, whereas, lipid and CWM content was negatively correlated. Air classification at lower air flows (smaller cut sizes) resulted in protein and starch fractions containing higher levels of protein. Starch separation efficiency and protein separation efficiency generally increased with increasing protein content.
The Two Drosophila Telomeric Transposable Elements Have Very Different Patterns of Transcription

The transposable elements HeT-A and TART constitute the telomeres of Drosophila chromosomes. Both are non-long terminal repeat (LTR) retrotransposons, sharing the remarkable property of transposing only to chromosome ends. In addition, strong sequence similarity of their gag proteins indicates that these coding regions share a common ancestor. These findings led to the assumption that HeT-A and TART are closely related. However, we now find that these elements produce quite different sets of transcripts. HeT-A produces only sense-strand transcripts of the full-length element, whereas TART produces both sense and antisense full-length RNAs, with antisense transcripts in more than 10-fold excess over sense RNA. In addition, features of TART sequence organization resemble those of a subclass of non-LTR elements characterized by unequal terminal repeats. Thus, the ancestral gag sequence appears to have become incorporated in two different types of elements, possibly with different functions in the telomere. HeT-A transcripts are found in both nuclear and cytoplasmic cell fractions, consistent with roles as both mRNA and transposition template. In contrast, both sense and antisense TART transcripts are almost entirely concentrated in nuclear fractions. Also, TART open reading frame 2 probes detect a cytoplasmic mRNA for reverse transcriptase (RT), with no similarity to TART sequence 5′ or 3′ of the RT coding region. This RNA could be a processed TART transcript or the product of a “free-standing” RT gene. Either origin would be novel. The distinctive transcription patterns of both HeT-A and TART are conserved in Drosophila yakuba, despite significant sequence divergence. The conservation argues that these sets of transcripts are important to the function(s) of HeT-A and TART.
Hybrid numerical–asymptotic code for dispersive-pulse propagation calculations

A fast, hybrid numerical–asymptotic algorithm for the calculation of the dynamical field evolution that is due to an arbitrary input pulse in any linear dispersive, attenuative medium is presented. The algorithm combines the numerical efficiency of the fast-Fourier-transform algorithm over a finite frequency domain that encompasses all the medium resonances with the accuracy and analytical efficiency of the asymptotic description that fully accounts for the high-frequency structure above the highest resonance that is characteristic of the dispersive medium.
The mechanism for the disparate actions of calcitriol and 22-oxacalcitriol in the intestine

Oxacalcitriol (OCT) is one of several new analogs of vitamin D that retain many of the therapeutically useful properties of 1,25- dihydroxyvitamin Ds (1,25-(OH),D,), but have much less calcemic activity. In the present study we examined the actions of OCT on intestinal calcium absorption and calbindin D9k mRNA in vitamin D- deficient rats. After ip injection of OCT (1 rg/kg), calcium absorption increased significantly by 2 h and was maximal at 4 h (2.5-fold above control), but returned to pretreatment levels by 16 h. In contrast, the same dose of 1,25-(OH)2D3 caused a 3-fold increase in calcium absorp- tion, which lasted more than 48 h. The transient effect of OCT on calcium absorption was also observed when the analog was infused at a dose of 1 rg/kg.day for 3 days. At the end of the infusion period, calcium absorption was 3-fold higher than that in vehicle-infused controls, but fell to pretreatment levels by 24 h after removing the minipumps. The time courses for induction of calbindin D9k mRNA were similar for OCT and 1,25-(OH)zDs, with no change observed until more than 4 h after injection. However, calbindin mRNA levels re- turned to pretreatment values more rapidly in the OCT-treated rats. Consistent with these findings, we observed that a 1 pg/kg dose of (3H) OCT was completely cleared by 4-6 h after injection. This was paral- leled by a loss of VHlOCT associated with the intestinal vitamin D receptdr. The rapid clearance of OCT is probably due to ita low affinity for the serum vitamin D-binding protein. This low affinity would also be expected to allow greater accessibility to target cells. In support of this, we found that higher amounts of OCT than 1,25-(OH)*D3 were associated with the intestinal vitamin D receptor after the injection of several doses of these tritiated ligands. In summary, our results indicate that the pharmacokinetic properties of OCT are responsible at least in part for its low calcemic activity. Furthermore, comparison of the transient elevation of calcium absorption by OCT with ita more pro- longed effects on PTH and calbindin D9k indicates that each action of vitamin D compounds has a distinct biological half-life. The short circulating half-life of OCT can exploit these differences to provide a therapeutic advantage in the treatment of vitamin D-responsive dis- eases.
PRICE UNCERTAINTY, FACTOR SUBSTITUTION, AND THE LOCATIONAL BIAS OF BUSINESS TAXES*

Consideration of the integrated production-location problem is extended to include several types of business taxes. Many of these taxes are technologically and spatially neutral under certainty, but are shown to be nonneutral when factor prices are stochastic and the firm is risk averse, even when the tax is spatially uniform. Consequently, even a nationally uniform tax can have regional biases and can encourage migration of plants. When factor prices are uncertain, the effects of taxes on output rates, input ratios, and plant location vary with the form of the tax imposed as well as the amount to be paid. Income taxes involve the taxing authority in sharing the risk with the firm and are shown to promote risk taking by the firm and induce the expansion of output. Locational incentives which are mutually beneficial to firms and the government are presented.
TERAHERTZ TIME-DOMAIN SPECTROSCOPY BASED ON NONLINEAR OPTICS

We present a brief review of the use of nonlinear optics for broadband terahertz (THz) time-domain spectroscopy with femtosecond laser pulses. The generation of THz pulses is accomplished by optical rectification and coherent detection by electro-optic sampling or field-induced second-harmonic generation. The approach permits exceptional time response, as well as the possibility for multichannel detection schemes.
Research topics in trade space exploration

This paper presents a number of new, open research topics in design methods emerging from our use of an internally developed method for supporting trade space exploration for complex systems, to include spacecraft. The research topics focus on how the trade space exploration process affects how models are assembled and exercised, how features in the trade space can be traced back to their source in the models, and on how the process of increasing refinement in modeling is itself a tropic of research
Primary Prevention of Coronary Heart Disease in the Elderly

OBJECTIVE:To review relevant literature supporting the use of antihypertensive agents, lipid-lowering agents (i.e., statins), and aspirin therapy for the primary prevention of coronary heart disease (CHD) in an elderly patient population (age ≥65 y).DATA SOURCES:A MEDLINE search (1988–January 2003) was conducted.STUDY SELECTION AND DATA EXTRACTION:Primary and tertiary literature involving the uses of antihypertensives, statins, and aspirin therapy in the elderly were reviewed.DATA SYNTHESIS:Mortality due to CHD in the US population has decreased 40–50% over the last 30 years; however, CHD remains the leading cause of morbidity and mortality in elderly persons. As the population continues to age, the number of older adults eligible for primary prevention will rise. The American Heart Association clinical practice guidelines for the primary prevention of CHD were updated in 2002; however, they are based on findings from clinical trials that enrolled predominantly middle-aged white men. The recommendations f...
On the propagation of bubbles in the geomagnetic tail

Abstract. Using three-dimensional magnetohydrodynamic simulations, we investigate the propagation of low-entropy magnetic flux tubes ("bubbles") in the magnetotail. Our simulations address fundamental properties of the propagation and dynamics of such flux tubes rather than the actual formation process. We find that the early evolution, after a sudden reduction of pressure and entropy on a localized flux tube, is governed by re-establishing the balance of the total pressure in the dawn-dusk and north-south directions through compression on a time scale less than about 20s for the typical magnetotail. The compression returns the equatorial pressure to its original unperturbed value, due to the fact that the magnetic field contributes only little to the total pressure, while farther away from the equatorial plane the magnetic field compression dominates. As a consequence the pressure is no longer constant along a flux tube. The subsequent evolution is characterized by earthward propagation at speeds of the order of 200-400km/s, depending on the initial amount of depletion and the cross-tail extent of a bubble. Simple acceleration without depletion does not lead to significant earthward propagation. It hence seems that both the entropy reduction and the plasma acceleration play an important role in the generation of fast plasma flows and their propagation into the near tail. Earthward moving bubbles are found to be associated with field-aligned current systems, directed earthward on the dawnward edge and tailward on the duskward edge. This is consistent with current systems attributed to observed bursty bulk flows and their auroral effects. Key words. Magnetospheric physics (magnetospheric configuration and dynamics; magnetotail; plasma sheet)nguage:
The Effects of Envy on Reciprocation in a Social Dilemma

This article presents two studies that address Axelrod’s (1984) prescription to not worry about the outcomes that others receive in a mixed-motive situation. The first study demonstrated that people do attend and react to others’ outcomes, with people whose outcomes were of a lesser magnitude than the opponent being uncooperative and people with greater-magnitude outcomes being very cooperative. This was true even though own and other outcomes were linearly equivalent. The second study showed that dispositional envy can predict rate of cooperation and that referent cognitions theory can be applied to help alleviate the impact of differing outcomes, both by making amends for small-magnitude outcomes at the end of the game (amelioration) and by providing a reasonable explanation for why the differences in outcomes exist (justification), although the former intervention was ineffective with people with high levels of dispositional envy. Discussion focuses on the role of mental simulations in the reduction of...
Excellence in Education Versus High-Stakes Standardized Testing

The evidence is missing for high-stakes standardized testing of either intelligence or achievement as a reform tool, a tool for producing higher student achievement. The focus on invalid testing allows us to ignore the well-documented importance of the quality of teaching as a key factor in student achievement. There is no doubt that teachers can become powerful agents in raising the academic performance of children to high levels, regardless of common impediments such as poverty, bilingualism, and so forth. With the extreme and almost exclusive focus on high-stakes testing, we lose the opportunity to support valid staff development that would make all of our teachers powerful.
Improving Machine Learning Approaches to Coreference Resolution

We present a noun phrase coreference system that extends the work of Soon et al. (2001) and, to our knowledge, produces the best results to date on the MUC-6 and MUC-7 coreference resolution data sets --- F-measures of 70.4 and 63.4, respectively. Improvements arise from two sources: extra-linguistic changes to the learning framework and a large-scale expansion of the feature set to include more sophisticated linguistic knowledge.
The Organization of Political Space and Citizen Responses to Dissatisfaction in Urban Communities: An Integrative Model

For more than three decades, the "spatial dimensions of urbanism" have provided an important theoretical tool for studying urban government and politics. Unfortunately, the now rather voluminous literature on the subject remains "painfully eclectic" (Goodman, 1977, p. 245). This is especially true in the refining of various propositions concerning the linkages between jurisdictional boundaries and individual attitudes and behaviors associated with political participation. Specifically, two problems confront the literature. First, there is a lack of an integrated model that encompasses the full range of behavioral and attitudinal responses to dissatisfaction with urban politics and accounts for the individual's choice from among those alternative response patterns. Second, the literature only incompletely and inappropriately addresses the impact of correspondence or lack thereof between spatial contours of social worlds and political jurisdictions on modes of political participation. This essay addresses t...
Relation between transmission and throughput of slotted ALOHA local packet radio networks

A new method for the exact calculation of the throughput of a centralized slotted ALOHA packet radio network over slow Rayleigh-fading channels is presented and the results are compared with the computer simulations. Also, upper and lower bounds on the performance are provided. The effects of capture on the throughput of the system are related to the modulation and coding technique, signal to noise ratio of the received signal, general terminal distribution in the area, and the length of the transmitted packets. The binary phase shift keying (BPSK), coherent and noncoherent binary frequency shift keying (FSK) modulations and BCH coding are considered for the exact calculations. The results of the analysis show that the maximum average throughput of the slotted Aloha packet radio network is around 60% rather than 36% predicted from the simplified analysis. In contrast with some previous reports, it is shown that the throughput of the system is not affected significantly by the use of coding or the change of packet lengths. >
Ultrasound-based servoing of manipulators for telesurgery

Certain minimally invasive surgical procedures involve the treatment of highly precise target locations within deformable tissues. While preoperative MRI and CT models can be used for surgical planning, they provide only coarse guidance during surgery due to their limited resolution and owing to tissue deformation. Ultrasound imaging is a promising means of obtaining real-time intraoperative data for target localization that is particularly well suited to minimally invasive surgery due to its portability, speed, and safety. This paper presents a system, in which ultrasound images are used to guide a manipulator to a surgical site. Electromagnetic tracking of the ultrasound probe is used to orient the images. These are then segmented in real time to determine target locations. Finally, target coordinates are used to produce control inputs to drive the manipulator to the target site. The potential of the approach is demonstrated experimentally using a manipulator arm, phantom target, and commercial ultrasound machine.
Bond Activation with an Apparently Benign Ethynyl Dithiocarbamate ArCCSC(S)NR2

The hedgehog molecule: A simple ethynyl dithiocarbamate [Ar-C≡C-S-C(S)NR(2)] is able to cleave a broad range of enthalpically strong σ bonds and to activate carbon dioxide and elemental sulfur. Depending on the substrate, the bond activation process involves either the existence of an equilibrium with the nonobservable mesoionic carbene isomer or the cooperation of the nucleophilic carbon-carbon triple bond and the electrophilic CS carbon atom.
Do golf courses reduce the ecological value of headwater streams for salamanders in the southern Appalachian Mountains

a b s t r a c t Recent studies indicate golf courses may have a potential role in biodiversity conservation and management in human dominated landscapes. To serve this ecological role, effects of current golf course management practices must first be better understood. We sampled larval, juvenile, and adult stream salamanders in transects located upstream, through, and downstream of managed fairways of 10 golf courses in western North Carolina, USA. We measured in-stream and riparian habitat characteristics and tested for nitrate and pesticide chemicals to explain trends in salamander abundances and diversity. Stream transects located directly on fairways contained lower abundance of larval, metamorph, juvenile, and adult salamanders than either upstream or downstream transects. The species diversity of aquatic larval and metamorph salamanders on fairways was also reduced but only compared to the upstream transects, and terrestrial juvenile and adult diversity did not differ among the three transect locations. Our analysis found that leaf litter depth, CWD, soil moisture, and buffer width parameters found within several models were positive predictors of salamander abundance and diversity. Nitrate was not detected at any of the stream reaches and two of the 16 pesticide chemicals screened were only detected in negligible proportions. Our findings suggest golf courses in western North Carolina can currently provide viable habitat for stream salamanders in reaches upstream and downstream of managed areas of courses and streams running through fairways may be enhanced through simple management practices such as retaining woody debris, leaf litter, and restoring a riparian buffer.
Dilemmas of Change in Mexican Politics

Despite the past resilience of Mexico's authoritarian regime, the severity of the country's post-1982 economic crisis raises major questions concerning the future direction of Mexican politics. This review examines recent developments affecting two key members of the governing revolutionary coalition, the political elite and organized labor. The political elite's unity is potentially threatened by shifts in education and recruitment patterns, and widespread uncertainty regarding Mexico's economic future has produced the most serious intra-elite division since the early 1950s. Prolonged economic crisis has also placed severe strains on state-labor relations, and the government's implementation of a new development strategy may lead to a substantial redefinition of organized labor's overall position in the Mexican regime. These changes pose significant challenges to the political elite's ability to preserve a broad-based governing coalition and political openness while managing the economic crisis and conflicting development priorities.
Diagnosis of Pleural Effusions by Chromosome Analysis

Cytogenetic changes, namely numerical (aneuploidy) and morphologic chromosome abnormalities including markers, clearly indicate the presence of malignant cells. To compare the utility of chromosome and cytogenetic analysis, the idiopathic pleural effusions of 60 patients were subjected to a double-blind analysis. A fluid was considered "positive" for malignancy if there was a marker chromosome, or if 10 percent of metaphases were hyperdiploid. Of the 33 neoplastic effusion, 30 (91 percent) were diagnosed "positive" by chromosome analysis whereas only 21 (64 percent) were classified "positive" or "suggestive positive" by cytology. All 27 benign effusions were correctly diagnosed by cytology; however, two were labelled "positive" by chromosome analysis. Combining the results of cytologic and chromosome analysis did not increase the number of "positive" diagnoses.
Antibiotic Resistance in Primary and Persistent Endodontic Infections

Abstract Introduction The presence of antibiotic resistance genes in endodontic microorganisms might render the infection resistant to common antibiotics. The aims of this project were to identify selected antibiotic resistance genes in primary and persistent endodontic infections and to determine the effectiveness of contemporary endodontic procedures in eliminating bacteria with these genes. Methods In patients undergoing primary endodontic treatment or retreatment, the root canals were aseptically accessed and sampled before endodontic procedures as well as after contemporary chemomechanical preparation and medication with calcium hydroxide. Identification of the following antibiotic resistance genes was performed by using polymerase chain reaction: bla TEM-1 , cfx A, bla Z, tet M, tet W, tet Q, van A, van D, and van E. Limited phenotypic identification and antibiotic susceptibility verification were also performed. Results Overall, there were 45 specimens available for analysis, 30 from primary and 15 from persistent endodontic infections. In preoperative specimens, only bla TEM-1 was significantly more prevalent in primary versus persistent infections ( P = .04). After contemporary treatment procedures, there was an overall reduction in prevalence of these genes ( P bla TEM-1 and tet W were significantly reduced ( P cfx A, bla Z, and tet Q were eliminated, but there was no change in tet M. No specimens contained vanA , vanD , or vanE . Antibiotic susceptibility testing showed significant differences among the antibiotics ( P Conclusions bla TEM -1 was more prevalent in primary than persistent infections. Vancomycin resistance was not present. The genes identified were reduced with treatment except for tet M. Genetic testing might be useful as a screening tool for antibiotic resistance.
Ultra fast-fiber-optic networks using all-optical processing

The use of optical signal processing and novel optical architectures in networks is discussed. Examples of three experimental all-optical passive star networks are presented: asynchronous code-division multiple-access (spread-spectrum), fixed-assignment (TDMA) time-division multiple-access (at 500 Mb/s) and a 12.5-Gb/s all-optical, self-routing, strictly nonblocking photonic switch. The feasibility of future photonic networks is also discussed. To reduce the bandwidth requirements of the receiver, it is necessary to perform the data regeneration process optically, using, for example, bistability or four-wave mixing. In CDMA, optical threshold detection of the autocorrelation peak is required, and in TDMA, optical coincidence of the delayed clock and the data is needed. >
Arabidopsis MICROTUBULE-ASSOCIATED PROTEIN18 Functions in Directional Cell Growth by Destabilizing Cortical Microtubules

Microtubule-associated proteins (MAPs) play important roles in the regulation of microtubule function in cells. We describe Arabidopsis thaliana MAP18, which binds to microtubules and inhibits tubulin polymerization in vitro and colocalizes along cortical microtubules as patches of dot-like structures. MAP18 is expressed mostly in the expanding cells. Cells overexpressing MAP18 in Arabidopsis exhibit various growth phenotypes with loss of polarity. Cortical microtubule arrays were significantly altered in cells either overexpressing MAP18 or where it had been downregulated by RNA interference (RNAi). The cortical microtubules were more sensitive to treatment with microtubule-disrupting drugs when MAP18 was overexpressed, but more resistant when MAP18 was eliminated in cells expressing MAP18 RNAi. Our study demonstrated that MAP18 may play a role in regulating directional cell growth and cortical microtubule organization by destabilizing microtubules.
G protein-dependent activation of smooth muscle eNOS via natriuretic peptide clearance receptor

In gastrointestinal smooth muscle, the neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) induce relaxation by interacting with VIP2/PA...
ICANN Can: Contracts and Porn Sites - Choosing 'to Play Internet Ball in American Cyberspace'

We argue in this article that the history and structure of the International Corporation for Assigned Names and Numbers (ICANN) illustrates that, despite its claims to the contrary, ICANN does now make and implement policy in non-technical areas of Internet governance. This article examines how ICANN-imposed obligations within the Domain Name System (DNS) have been used to implement those policy objectives. Efforts at protecting children from age-inappropriate sexually explicit material online should be as important a policy for ICANN as is protecting the economic value of big corporations trademarks. Terms within ICANN's Uniform Domain-name Dispute-Resolution Policy (UDRP) can be meaningfully engaged in helping countries carry out reasonable pornography regulation. This approach does not require radical changes in law or structure; instead, it enables governments to enforce Internet pornography and obscenity laws that have been difficult to enforce because of the Internet's borderless nature. This Article describes how UDRP language, and the even more extensive language adopted by many ICANN-authorized registrars, registries and Internet service providers, gives the legal basis for removing Internet sites that violate the law. We then detail how this approach can be implemented in the United States under existing rules on jurisdiction and the reach of injunctions.
Advanced methods for extracting flow and combustion physics from high speed laser diagnostics

This paper investigates the characterization of combustion dynamics behind a V-gutter flame holder for a kerosene/air, turbulent, premixed flame using three mathematical methods. This work compares the application of two traditional methods, Fourier analysis and principle component analysis (PCA), against a new method, wavelet analysis (WA). The comparison focuses primarily on the examination of the characteristic frequencies inherent with flow-flame interactions under a change in inlet Mach number. Experimental data obtained at two inlet Mach numbers were analyzed using all three methods and major conclusions are threefold. First, when applied to each Mach number condition, all three methods reported frequency characteristics that were similar both quantitatively and qualitatively, proving the WA method’s viability for extracting the necessary information from the data. Second, the WA method was able to resolve the dynamics of the frequency components in the measurements, which revealed a single, dominant frequency peak for the Mach 0.15 inlet condition, but a much less intense, double frequency oscillation for the Mach 0.20 inlet condition. Third, these applications also demonstrated WA’s suitability for practical combustion measurements beyond chemiluminescence, such as its applicability to discrete signals, insensitivity to the choice of wavelet basis and to the target signal extracted from the raw measurements. The results obtained in this work demonstrate the value of the WA method for extracting dynamic, quantitative information from practical combustion measurements.
Ductal Carcinoma In Situ

This interactive feature offers a case vignette accompanied by essays that support either watchful waiting with close observation or lumpectomy with or without radiation. Share your comments and vote at NEJM.org.
Silicon ring strain creates high-conductance pathways in single-molecule circuits.

Here we demonstrate for the first time that strained silanes couple directly to gold electrodes in break-junction conductance measurements. We find that strained silicon molecular wires terminated by alkyl sulfide aurophiles behave effectively as single-molecule parallel circuits with competing sulfur-to-sulfur (low G) and sulfur-to-silacycle (high G) pathways. We can switch off the high conducting sulfur-to-silacycle pathway by altering the environment of the electrode surface to disable the Au–silacycle coupling. Additionally, we can switch between conductive pathways in a single molecular junction by modulating the tip–substrate electrode distance. This study provides a new molecular design to control electronics in silicon-based single molecule wires.
Integrated Hybrid Microcavities for Low Threshold Lasers

By integrating new gain into hybrid ultra-high-Q cavities, two types of low-threshold optically-pumped lasers are demonstrated. The Ti-enhanced Raman laser and the gold nanorod plasmonic laser both have sub-mW thresholds.
The role of positive illusions in employment relationships

Abstract Drawing from existing research and concepts in social psychology, we identify “positive illusions” as an important construct for understanding long-term, stable, and satisfying employment relationships. We argue that the cognitive processes that modify the way in which individuals view their world can aid in promoting and enhancing the quality of employment relationships. These largely non-conscious processes often aid in the construction of positively distorted beliefs, referred to as positive illusions, which act to diffuse feelings of uncertainty, and drive satisfaction and commitment in close relationships. Our theoretical analysis suggests the relevance of positive illusions in the context of employment relationships, and highlights its role specifically during negative organizational shocks. We explore theoretical connections and offer testable propositions on the role of positive illusions in understanding employment relationships. These propositions have important theoretical and practical implications for the (a) applicant stage of employment, (b) organizational entry and socialization, and (c) adapting to organizational change.