cssi/SciSciGPT-SciSciNet huggingface dataset:
Oxygen Dilation in Fetal Pulmonary Arterioles: Role of K+ Channels

Abstract Background. Oxygen is a potent stimulus for pulmonary vasodilation. Potassium channels have been implicated as both sensors and effectors for oxygen-induced changes in pulmonary vascular tone. We have examined the effect of potassium channel blockers on oxygen-induced vasodilation in isolated pulmonary arterioles from fetal rats at term. Materials and methods. Third generation pulmonary arterioles were isolated from fetal rats on Day 22 of gestation, cannulated, pressurized at constant distending pressures, and preconstricted by suffusion with a salt solution bubbled with a “hypoxic gas” mixture ( p O 2 ≤50 mm Hg). Oxygen-induced vasodilation was measured as percentage reversal of the “hypoxic” vasoconstriction after 30 min of suffusion with “normoxic” solution ( p O 2 90–145 mm Hg). Responses were recorded in the absence of blockers (controls) or in the presence of a voltage-gated K + channel (K v ) blocker, 4-aminopyridine; an ATP-sensitive K + channel (K ATP ) blocker, glibenclamide; a Ca 2+ -activated K + channel (K Ca ) blocker, charybdotoxin; or a nonspecific K + channel blocker, tetraethylammonium. Results. In control arterioles, normoxic suffusion for 30 min reversed hypoxic preconstriction by 83 ± 19%. 4-Aminopyridine significantly attenuated (44 ± 9%), and glibenclamide and charybdotoxin had no effect (80 ± 16 and 79 ± 20%) on the magnitude of normoxic vasodilation. Conclusions. Our results are consistent with a contribution of K v channels, but not K ATP or K Ca channels, to oxygen-induced vasodilation in third generation pulmonary arterioles from term fetal rats.
Structural and Computational Studies of the Staphylococcus Aureus Sortase B-Substrate Complex Provide New Insight into the Mechanism of Sortase Transpeptidases

Sortase cysteine transpeptidases covalently attach proteins to the bacterial cell wall or assemble fiber-like pili that promote bacterial adhesion. Members of this enzyme superfamily are widely distributed in Gram-positive bacteria which frequently utilize multiple sortases to elaborate their peptidoglycan. Sortases catalyze transpeptidation using a conserved active site His-Cys-Arg triad that joins a sorting signal located at the C-terminus of their protein substrate to an amino nucleophile located on the cell surface. In order to understand the molecular basis of substrate recognition, we solved a crystal structure of the Staphylococcus aureus Sortase B enzyme (SrtB) in a covalent complex with an analog of its NPQTN sorting signal substrate. The results of computational modeling, molecular dynamics (MD) simulations, and targeted amino acid mutagenesis indicate that the backbone amide of Glu224 and the side chain of Arg233 form an oxyanion hole in SrtB which stabilizes high-energy catalytic intermediates. Surprisingly, a highly conserved threonine residue within the bound sorting signal substrate facilitates construction of the oxyanion hole by stabilizing the position of the active site arginine residue via hydrogen bonding. MD simulations and primary sequence conservation suggest that the sorting signal-stabilized oxyanion hole is a universal feature of enzymes within the sortase superfamily.
Sequential Predictability Effects on Initiation Time and Movement Time for Adults and Children

First-grade children and adults performed a two-choice initiation-time/ movement-time task in which signals were (a) more likely to repeat than alternate, (b) more likely to alternate than repeat or (c) equally likely to alternate or repeat. Sequential predictability influenced initiation time but not movement time for adults and for children. These results do not support the suggestion (Wickens, 1974) that sequential predictability affects initiation time and movement time for children but only initiation time for adults. Adults and first graders did differ in their response to repeated events. Adults averaged faster initiation time for alternated than repeated responses and children averaged faster initiation time for repeated than alternated responses.
Hybrid launch isolation system

An innovative new hybrid isolation system has been developed to significantly increase the performance over a passive whole-spacecraft isolation design. The design builds upon the passive design and incorporates active components in parallel to the passive design. This means that if the active system fails, the passive system would be able to handle the isolation requirements. Preliminary results show that significant attenuation can occur using the hybrid isolation system over the passive isolation system. Also, it has been determined that the performance gained by the hybrid isolation system will be dependent on the stiffness of the launch vehicle. As this stiffness now becomes an important design parameter when developing a whole- spacecraft launch isolation system.
Neighbors and Neighborhoods: Effects on Marriage Timing

Studies of neighborhoods can benefit from data and theoretical frameworks that allow them to examine the differences between neighborhoods and neighbors. Without this distinction, it is unclear if it is characteristics of the people or the place that are associated with individual outcomes. Using data from the Chitwan Valley Family Study, I explore the differences between neighbors and neighborhoods and their associations with marriage timing. I hypothesize three mechanisms whereby neighbors influence individuals: information sharing, social modeling, and sanctions and rewards among a close primary residential group. I explore three domains in which these mechanisms are likely to operate: education, media consumption, and attitudes. Results indicate that when neighbors have attitudes favoring later marriage and being single, marriage rates decrease, even when controlling for measures that describe the neighborhood’s access to important resources in the form of institutions and services.
Radial arm maze performance of rats following repeated low level microwave radiation exposure.

We examined the possibility of changes in “working” memory of rats following whole body exposure to microwave (MW) radiation. During each of 10 days, we exposed rats within circularly polarized waveguides for 45 min to 2450 MHz fields at whole body SARs of 0.6 W/kg (2 μs pulses, 500 pps), followed by testing in a 12 arm, radial arm maze (RAM). Rats received a preexposure injection of one of three psychoactive compounds or saline, to determine whether a compound would interact with MW exposure to affect performance in the maze. Error rate, i.e., reentry into arms already visited, and time to criterion data for 10 consecutive days of testing were analyzed by a three way analysis of variance (ANOVA) using main effects of “exposure” and “drug” and a repeated factor of “test day.” Our alpha limit for significance was P < .05. Analyzes of error rates revealed no significant exposure effect, no significant drug effect and no significant interaction between the two main factors. There was a significant difference in test days, as expected, with repeated test-trial days, which indicates that learning was accomplished. There was no significant interaction of test day and the other two factors. The results of our analyzes of time to criterion data included no significant exposure effect, a significant drug effect, a significant test day effect, and a significant interaction between drug and test day factors. Post hoc analyzes of the drug factor revealed that rats treated with either physostigmine or nalrexone hydrochloride, took significantly longer to complete the maze task than rats pretreated with saline or with naloxone methodide. We conclude that there is no evidence from the current study that exposure to of MW radiation under parameters examined caused decrements in the ability of rats to learn the spatial memory task. Bioelectromagnetics 25:49–57, 2004. Published 2003 Wiley-Liss, Inc.
Physicians taught as residents to conduct smoking cessation intervention: a follow-up study.

Abstract Background. The influence of residency training on use of smoking cessation intervention (SCI) in future practice is unexamined. Methods. We surveyed 291 physicians who participated in SCI research during residency between 1986 and 1996. Half received SCI training; half did not. Best practice included: (1) identifying smokers; (2) advising cessation; (3) assisting with a plan; (4) arranging follow-up. Results. Forty-two percent of respondents were using best practices. Training per se was not associated with current use of best practices (relative risk = 1.04; adjusted relative risk [ARR] = 0.91). However, those who reported use of best practices in residency were twice as likely to currently use best practices [ARR = 2.0; 95% confidence interval (CI) 1.3, 2.9]. Resources associated with use of best practices included patient education materials (ARR = 1.8; CI 1.1, 2.7), staff familiar with SCI (ARR = 1.8; CI 1.2, 2.6), and opportunity for referral to cessation counselors/programs (ARR = 1.3; CI 1.0, 1.9). Resources related in a dose–response fashion to best practices: 24% of those without resources provide best SCI, 32% with any one resource, 51% with any two, and 74% with all three. Conclusions. To expand use of best SCI, residencies must ensure physicians use SCI skills, and health care systems must provide resources to facilitate intervention.
Design and simulation of a sequential kinking guardrail terminal

The process of using non-linear, large deformation finite element analysis to design a new guardrail terminal system is summarized. The simulation program LS-DYNA was used to develop a sequential kinking process for energy dissipation. The sequential kinking process involves using a deflector plate to force a steel beam guardrail element to be bent around a rigid beam until it forms a plastic hinge. Deformation is then localized at the plastic hinge until the hinge contacts the deflector plate and a new kink develops. Critical steps in the design process include selection of the deflector plate geometry and design of structural components required to support the system during a full-scale vehicular impact. This paper describes the use of LS-DYNA for these critical portions of the design process. Predictions of the energy dissipation for the sequential kinking impact head were only 7% below values obtained from dynamic impact tests.
Evolution of Gas and Stars in the Merger Galaxy NGC 1316 (Fornax A)

We present optical and archival X-ray data on the disturbed-morphology radio elliptical galaxy NGC 1316 (Fornax A), which displays numerous low surface brightness shells, loops, and tails. An extended (81'' × 27'', or 9 kpc × 3 kpc) emission-line region (EELR) at a projected distance of 35 kpc from the nucleus has been discovered in an approximately 90 kpc × 35 kpc, 3.0 × 109 LB⊙ tidal tail. The position and extreme size of the EELR suggest that it is related to the merger process. We suggest that the ionization mechanism of the EELR is shock excitation and that the gas is a remnant from the merger progenitor. X-ray emission is detected near two tidal tails. Hot, ~5 × 106 K, gas is probably the predominant gas component in the tidal-tail interstellar medium. However, based on the current tidal-tail (cold + warm + hot) gas mass, a large fraction of the progenitor gas may already reside in the nucleus of NGC 1316. The numerous and varied tidal-tail system suggests that a disk-disk or disk-E merger could have taken place ≥1 Gyr ago, while a low-mass, gas-rich galaxy would have started to merge ~0.5 Gyr ago.
TRENDS TO TRACK

Investment and growth in emerging markets will bring new opportunities, but with them added responsibility. Will companies be able to rise to meet the new responsibility agenda? Deloitte's John Connolly thinks so and argues that the business case is overwhelming.
Microleakage of conventional and microfilled composite restorative resins

Microfilled composite resins have been introduced in clinical dentistry because of the difficulty in finishing conventional composite resins satisfactorily. Owing to the difference in coefficients of thermal expansion of the two resin systems, the objective of this in vitro study was to evaluate microleakage of a conventional and a microfilled composite resin. Class V cavities with butt cavosurface margins were prepared in the middle third of the facial surfaces of the crowns of 80 noncarious human premolar teeth; they were acid etched within the preparations only. Forty preparations were restored with Concise composite and forty with Silar microfilled resin. Ten teeth from each group were subjected to cyclic temperature changes between 5 and 55 degrees C for 1000, 2500, or 5000 cycles, respectively, and ten teeth from each group were not cycled (controls). After suitable preparation, the teeth were immersed in 45Ca solution for 18 h and contact radiographs were prepared. Microleakage was scored 0-3 at both the cervical and occlusal margins of the restorations. Microleakage was significantly greater at the cervical margins than at the occlusal margins. Differences within occlusal and cervical microleakages among the two resins were not significant.
Potential free electron laser applications in chemical and molecular studies

Abstract Potential chemical applications of free electron lasers abound both in a scientific and a technological context. In this review specific spectral regimes of interest are highlighted as representing the areas of greatest need. Of greatest interest are lasers covering the VUV to soft X-ray region, followed by the IR regime 2.4–4.3 μm where high average power is required. Chemical applications would benefit significantly from the availability of FEL devices to the chemistry community.
Relativistic quantum calculations of spectroscopic properties of BiH

Abstract Complete active space MCSCF (CASSCF) followed by first-order configuration interaction (FOCI) calculations are carried out on 16 low-lying electronic states of Ge2. Among these, 14 electronic states are bound for which spectroscopic properties are calculated. Our calculations predict the spectroscopic properties of a number of states which are yet to be observed. A number of electronic transitions in the far-infrared to UV regions are also predicted, none of which has been observed yet.
The provisional license: nighttime and passenger restrictions--a literature review

Abstract Problem: Due to inexperience and inadequate driving skills, the road is a very risky place for young and beginning drivers, yet such experience and skills can only be built by increased driving and exposure to risks on the road. Graduated driver licensing (GDL) allows beginning drivers to get their initial driving experience under less risky conditions and gradually eases them into more complex driving situations. This paper reviews the literature exploring two key features of the intermediate licensing phase of GDL, nighttime driving restrictions and passenger restrictions. Method: Literature review. Results: Nighttime driving restrictions have been shown to effectively reduce the number and rate of crash involvements on the part of teenage drivers. Data suggest that having passengers in the car increases the likelihood of a fatal injury in young drivers and that this risk increases with the number of passengers. Young drivers were more likely to cause a crash when accompanied by their peers. Discussion: Nighttime driving and passenger restrictions are effective in decreasing injuries among teenage drivers and their passengers, especially in the context of a full GDL system. Several research questions remain to be answered in order to fully refine and optimize the impact of these provisional measures.
Monte Carlo estimate of the background field coupling renormalization in the Heisenberg model

Abstract We relate the difference between the bare and renormalized coupling constant in the O( n ) σ-model to the expectation value of one simple observable. For n = 3 numerical results are obtained on the lattice. At weak coupling they agree with perturbation theory, while at intermediate coupling consistency is found with results from Monte Carlo renormalizationgroup calculations
Three Critical Views of Functioning: Comparisons of Assessments Made by Individuals with Mental Illness, Their Case Managers, and Family Members.

Level of functioning measures are regularly used by mental health agencies to identify the strengths and abilities of individuals with mental illness. In spite of the important use of these measures, little research has compared the case manager's perception of functioning to that of individual consumers or their family members. In the current study, a comparison of the three groups produced moderate correlations in assessments of the consumer's functioning. Case managers rated the functioning of consumers significantly lower than did family members or consumers themselves with regard to Vocational Skills, Vocational Motivation, and Community Living Skills. The relevance of the three perspectives for community based service provision is discussed.
Role of ferric iron in platelet lipoxygenase activity.

Abstract Four iron chelating agents, EDTA, EGTA, ferron and orthophenan-throlene, were found to inhibit human platelet lipoxygenase activity in a dose-dependent manner. The inhibition produced by these chelators could be selectively reversed by the addition of ferric ion but not ferrous ion. The ID 50 for lipoxygenase activity directly correlated with the avidity of these compounds for ferric ion. Thus, human platelet lipoxygenase requires ferric ion for activity.
Relaxation solutions for inviscid axisymmetric transonic flow over blunt or pointed bodies.

A finite-difference relaxation method is presented for numerical solution of the full potential equation and exact boundary conditions for general axisymmetric bodies is inviscid, steady transonic flow. Body-normal coordinates are used in the nose region and sheared cylindrical coordinates are used on the afterbody to accommodate corners such as boattails and flares. An improved difference scheme is used which does not require that the flow be nearly alined with a coordinate direction in supersonic regions, and which treats either subsonic or supersonic free streams. Numerical results are illustrated for some simple classical shapes such as spheres and ellipsoids, and for more practical shapes like tangent-ogives with boattails. Special attention is given to bodies which have been studied for area-rule applications. Agreement with available experimental results is good in cases where viscous effects and wind-tunnel wall interference are not important.
Whole-body turnover of selenium in the rat.

SELENIUM has recently been shown to be an essential micronutrient for rats1 and ruminants2. These discoveries have directed attention to the lack of information concerning the metabolism of selenium in subtoxic amounts. The present communication gives results for whole-body turnover, or total excretion, of selenium by the rat over a prolonged period of time.
A flooded—starved design for nickel—cadmium cells

A somewhat analogous situation among groupings of alkaline fuel cells is described where the stochastic aspects were much more accurately documented and then it was illustrated how this problem was eliminated using straight forward principles of pore size engineering. This is followed by a suggested method of adapting these same design principles to nickel-cadmium cells. It must be kept in mind that when cells are cycled to typically twenty percent depth of discharge that eighty percent of the weight of the cell is simply dead weight. Some of this dead weight might be put to better use by trading it for a scheme that would increase the time during which the cell would be working more closely to its optimum set of operating parameters.
An animal training model for endoscopic treatment of Zenker's diverticulum.

Background Zenker's diverticulum (ZD) is an uncommon disease, which is typically treated surgically. The alternative to surgery is a diverticulotomy, performed endoscopically. Given the rarity of this condition, it is not possible to obtain training. There has been no animal model identified that resembles the disease in human beings. Objective To present an animal model of ZD that resembles the disease in human beings. Design We prospectively characterized the endoscopy, the radiography, and the histologic anatomy of the pharyngeal diverticulum in the pig. Settings Domestic pigs scheduled for euthanasia underwent radiography and endoscopy and, after euthanasia, neck dissection of the pharyngeal diverticulum. Interventions and Methods Thirteen consecutive animals were studied. Pictures were taken for the endoscopic view, as well as radiographies during barium swallow in 1 pig. The neck region was dissected, and the pharynx and the upper esophagus were extracted. The size of the diverticulum was measured, and the block was fixed in formalin. Fixed specimens were cut in the transverse and coronal axis, and pictures were taken. The septum between the diverticulum and the esophagus was reviewed microscopically. Results The pharyngeal diverticulum measured an average of 2.7 cm (1.3-5 cm), depending on the size of the pig. From an endoscopic and radiologic perspective, the pig pharyngeal diverticulum is identical to a ZD. The septum contains muscle as well as fibrous tissue and fat. These anatomical characteristics closely resemble the anatomy in human beings. Conclusions We believe that we established an animal training model for the endoscopic treatment of ZD.
Studies on the mechanism of action of probucol

Earlier clinical studies suggested that probucol lowers plasma levels of low density lipoprotein (LDL) by increasing the rate of its removal. The drug has been shown to be effective in patients lacking the LDL receptor and, more recently, in LDL receptor-deficient rabbits. These latter studies showed that probucol increased the fractional catabolic rate of LDL by 40% to 50%. This finding in a receptor-deficient model implies that probucol can enhance the removal of LDL cholesterol by alternative pathways. Because the same enhanced removal was seen when LDL from probucol-treated rabbits was injected into untreated rabbits, it appears that the drug somehow alters the metabolic properties of the LDL itself rather than the metabolic behavior of the tissues of treated animals. Whether or not this mechanism explains the action of probucol in man remains to be determined. It has been postulated that the oxidative modification of LDL might contribute to atherogenesis by facilitating lipid accumulation in macrophages (foam cells) and by inhibiting macrophage motility. LDL resists oxidative modification, however, when probucol is added to in vitro incubations or when the LDL itself is isolated from probucol-treated patients. These findings lay the groundwork for evaluating the possible in vivo significance of LDL oxidation.
Studies of the Ag-Ge(100) interface

The growth mechanism, chemical interaction, crystallographic relationships, and electronic properties of Ag deposited at room temperature on Ge(100)-(2\ifmmode\times\else\texttimes\fi{}1) were studied. Nucleation of deposited Ag at about ⅓ monolayer coverage to form flat and metallic Ag(110) islands was observed with high-energy electron diffraction and photoemission from the valence bands. The growth of Ag at higher coverages was determined to be three dimensional. The $3d$ core levels of surface atoms of Ge(100)-(2\ifmmode\times\else\texttimes\fi{}1) did not shift relative to the bulk with Ag coverage of a few monolayers, indicating a very weak interaction between Ag and Ge and negligible intermixing. Annealing experiments showed that the deposited Ag became highly clustered at elevated temperatures and did not wet the Ge(100)-(2\ifmmode\times\else\texttimes\fi{}1) surface. We will compare the present results with those for Ag deposited on Ge(111).
Metal-assembled cobalt(II) resorc[4]arene-based cage molecules that reversibly capture organic molecules from water and act as NMR shift reagents.

The complex Co4128- is a tetranuclear cobalt(II) cage compound that assembles in aqueous solutions above pH 4 and is capable of encapsulating a variety of organic guest molecules, for example, benzene, hexane, chlorobutane, butanol, and ethyl acetate. Ligand 1 is a resorc[4]arene-based molecule with iminodiacetate moieties appended to its upper rim. 1H NMR studies of Co4128-·guest complexes demonstrate inclusion of nonpolar hydrocarbons, substituted phenyls, alcohols, halogen-containing hydrocarbons, and polar organic molecules. The complex Co4128- acts as an NMR shift reagent and causes substantial upfield isotropic hydrogen shifts (−30 to −40 ppm) in the guest molecule and separation of the guest hydrogen chemical shifts by typically 12 ppm. The complex Co4128- will encapsulate molecules with fewer than eight atoms in a linear chain, mono- and disubstituted benzenes, and polar molecules with greater than two carbon atoms. The solid-state structure of Ba4[Co412·C6H5C2H5] shows a disordered guest molecule...
(3+1)-dimensional optical soliton dragging logic.

A review of the varieties of optical solitons and their possible interactions, combined with the requirements for a robust digital logic gate motivate the use of (3+1)-dimensional optical solitons (light bullets) as information carriers and soliton dragging gates as switches. Soliton dragging is the asymmetric interaction between two initially overlapping, orthogonally polarized solitons propagating at different angles so that a weak signal soliton can drag a strong pump out of a spatial aperture, thereby implementing a phase-insensitive, high-contrast, logical switch with gain. Light bullets may be an ideal choice for use in these soliton dragging gates but are unstable in Kerr media, but stable (for sufficient pulse energy) in materials with physically reasonable saturating or negative ${\mathit{n}}_{4}$${\mathit{I}}^{2}$ nonlinearities. An efficient technique for the propagation of spherically symmetric (3+1)-dimensional field envelopes is developed and used to verify the theoretical stability predictions. A split-step numerical algorithm that models the propagation and phase-independent interaction of arbitrary (3+1)-dimensional, vector e.m. fields in anisotropic media with up to sixth-order tensor nonlinearities is developed and used to demonstrate the features of the gates. NOT and single-stage, two- and four-input NOR light-bullet dragging logic gates are simulated and their performance over a range of operating parameters is presented. It is shown that, with material parameters in the range of those currently available from highly nonlinear organic crystals, high-contrast, all-optical, soliton logic gates with a clock rate greater than 1 THz, latency of a few picoseconds, and switching energy of 25 pJ may be possible.
Journeys of Expansion and Synopsis: Tensions in Books That Shaped Curriculum Inquiry, 1968–Present

AbstractIn honor of the 40th volume of Curriculum Inquiry, I begin by claiming that pursuit of questions about what is worthwhile, why, and for whose benefit is a (perhaps the) central consideration of curriculum inquiry. Drawing autobiographically from my experience as an educator during the past 40 years, I sketch reflections on curriculum books published during that time span. I situate my comments within both the historical backdrop that preceded the beginning of Curriculum Inquiry and the emergence of new curricular languages or paradigms during the late 1960s and early 1970s. I suggest that two orientations of curriculum books have provided a lively tension in curriculum literature—one expansive and the other synoptic—while cautiously wondering if both may have evolved from different dimensions of John Dewey’s work. I speculate about the place of expansion and synopsis in several categories of curriculum literature: historical and philosophical; policy, professional, and popular; aesthetic and artis...
Segmentation Of Specular Highlights From Object Surfaces

A major hindrance to image segmentation tasks are the presence of specular highlights on object surfaces. Specular highlights appear on object surfaces where the specular component of reflection from illuminating light sources is so dominant that most detail of the object surface is obscured by a bright region of reflected light. Specular highlights are very common artifacts of most lighting environments and are not part of the intrinsic visible detail of an object surface. As a result, in addition to obscuring visible detail, specular highlight regions of an image can easily deceive image understanding algorithms into interpreting these regions as separate objects or regions on an object with high albedo. Recently, a couple of approaches to identifying specular highlight regions in images of object surfaces have produced some good results using color analysis. Unfortunately these methods work only for dielectric materials (e.g. plastic, rubber etc..) and require that the color of the object be different from the color of the light source. In this paper a technique is presented exploiting the polarization properties of reflected light to identify specular highlight regions. This technique works for both dielectric and metal surfaces regardless of the color of the illuminating light source, or the color detail on the object surface. In addition to separating out diffuse and specular components of reflection, the technique presented here also as a bonus can identify whether certain image regions correspond to a dielectric or metal object surface. Extensive experimentation will be presented for a variety of dielectric and metal surfaces, both polished and rough. Experimentation with coated surfaces using the technique presented here have not yet been studied.
Ultrastructure of osmoregulatory organs in larvae of the brackish-water mosquito, Culiseta inornata (Williston).

The ultrastructure of the Malpighian tubules, ileum, rectum, anal canal, and anal papillae of larvae of the mosquito Culiseta inornata was examined. The Malpighian tubules, rectum, and anal papillae have many of the ultrastructural features characteristic of ion transport tissues, i.e., elaboration of the basal and apical membranes and a close association of these membranes with mitochondria. The Malpighian tubules possess two cell types, primary and stellate. The larval rectum of C. inornata is composed of a single segment containing a homogenous population of cells. In this respect, the larval rectum of C. inornata is distinct from that of saline-water species of Aedes. The cells in the larval rectum of C. inornata, however, closely resemble those of one cell type, the anterior rectal cells, of the saline-water mosquito Aedes campestris with regard to cell and nuclear size, the percentage of the cell occupied by apical folds, and mitochondrial density and distribution. No similarities can be found between the rectum of C. inornata and the posterior segment of the saline-water Aedes, which functions as a salt gland. On this basis, we have postulated that the rectum of C. inornata does not function as a site of hyperosmotic fluid secretion. The ultrastructure of the anal papillae of C. inornata is consistent with a role in ion transport. The significance of these findings to comparative aspects of osmoregulatory strategies in mosquito larvae is discussed.
Environmental Enrichment for Laboratory Rodents

Modernization of housing and husbandry techniques for rodents has minimized confounding variables. The result has been vastly improved health maintenance and reproducibility of research findings, advances that have decreased the numbers of animals needed to attain statistically significant results. Even though not all aspects of rodent manipulation have been strictly defined, as housing and handling procedures have become increasingly standardized, many animal care personnel have recognized the lack of complexity of the rodents' environment. Concern for this aspect of animal well-being has led many research facilities to provide "environmental enrichment" for rodents. Additionally, regulatory agencies in the United States and Europe have also been increasingly concerned about this issue relative to laboratory animal husbandry. However, little is known about the influence such husbandry modifications may have on biological parameters. In this article, laws and guidelines relating to rodent enrichment are reviewed, the natural behaviors of select rodent species are discussed, and an overview of widely used types of enrichment in laboratory rodent management is provided. The literature evaluating effects of rodent enrichment is reviewed both in terms of neurological development and as an experimental variable, and results of a study evaluating the effect of enrichment on immune and physiological parameters are reported. Survey data on current enrichment practices in a large multi-institutional organization are presented, and practical aspects requiring consideration when devising a rodent enrichment program are discussed.
The response of the tyrosine hydroxylase gene to cyclic AMP is mediated by two cyclic AMP-response elements.

: Tyrosine hydroxylase (TH) gene transcription rate is stimulated by cyclic AMP in cultured rat pheochromocytoma cells. This effect is at least partially due to the interaction of transcription factors with the canonical cyclic AMP-response element (CRE) at position −45 to −38 within the TH gene promoter. In this study we test whether a region of the TH gene promoter, which is adjacent to and upstream of the canonical TH CRE, also participates in the response of the promoter to cyclic AMP. Using electrophoretic mobility shift assays, we demonstrate that nuclear proteins from rat pheochromocytoma cell lines bind to the region of the TH gene from −102 to −73. A comparison of promoter sequences indicates that sequences within this region of the TH gene are highly homologous to proenkephalin promoter sequences (between −110 and −80) designated ENKCRE-1 and ENKCRE-2. We designated the TH gene sequence homologous to ENKCRE-1 as TH E1 and the sequence homologous to ENKCRE-2 as TH E2. Competition displacement binding assays suggest that protein binding to the −102/−73 region of the TH gene is critically dependent on the TH E1 sequence. Transient transfection assays using minimal promoter constructs demonstrate that this region acts as a cyclic AMP-responsive element. Mutagenesis of the TH E1 sequence within the normal context of the TH gene proximal promoter leads to a 50% decrease in the cyclic AMP inducibility of the promoter. These results support the hypothesis that the full response of the TH gene to cyclic AMP requires both the canonical TH CRE and this newly discovered element, which we term TH CRE2.
Theory of directed polymers

We develop a theory of polymers in a nematic solvent by exploiting an analogy with two-dimensional quantum bosons at zero temperature. We argue that the theory should also describe nematic polymers in an isotropic solvent. The dense phase is analyzed in a Bogoliubov-like approximation, which assumes a broken symmetry in the phase of the boson order parameter. We find a stiffening of the longitudinal fluctuations of the nematic field, calculate the density-density correlation function, and extend the analysis to the case of ferro- and electrorheological fluids. The boson formalism is used to derive a simple hydrodynamic theory which is indistinguishable from the corresponding theory of nematic polymers in an isotropic solvent at long wavelengths. We also use hydrodynamics to discuss the physical meaning of the boson order parameter. A renormalization-group treatment in the dilute limit shows that logarithmic corrections to polymer wandering, predicted by de Gennes, are unaffected by interpolymer interactions. A continuously variable Flory exponent appears for polymers embedded in a two-dimensional nematic solvent. We include free polymer ends and hairpin configurations in the theory and show that hairpins are described by an Ising-like symmetry-breaking term in the boson field theory.
Determination of Rheological Behavior of Tomato Concentrates Using Back Extrusion

The back extrusion testing technique can be a very useful tool in assessing the rheological behavior of non-Newtonian fluids (e.g. tomato concentrates). In this procedure, an Instron Model 1122 Universal Testing Machine (with stainless steel, solid rod attachment) was used to measure the forces developed as diluted tomato paste was back extruded in a simple piston/annular cylinder geometry. Assuming power law behavior, the force-distance data for extrusions at different piston velocities were analyzed to yield the dimensionless flow behavior index (n) and the consistency coefficient (k) for each sample. Back extrusion measurements were performed on hot break and cold break tomato concentrates with different % total solids. For comparison, rheological measurements were also done on a set of samples with a Carri-Med Controlled Stress Rheometer.
Behavior of metallic electrodes modified with a polymer derived from 4-(β-trimethoxysilyl)ethylpyridine. Charge transport, pH sensitivity, and anion selectivity

Pt electrodes can be modified with 4-(β-trimethoxysilyl)ethylpyridine to produce a surface-bound polymer, (SiPy)n, yielding a pH sensitive, anion selective interface when Γpy≥10−7 mol/cm2. At pH≥6 Pt/[(SiPy)n]surf. electrodes are insulated from a large variety of solution redox species, giving ∼1% of the current observed at a naked surface. Below pH 5 anions such as M(CN)yx− (M=Fe, Ru, Mo, Co; y=6 or 8; x=3 or 4), naphthoquinone sulfonate, indigo carmine and I− may be firmly electrostatically bound in the [(SiPyH+)n]surf. polymer. For pH<5 the Pt/[(SiPyH+)n]surf. electrodes show good response to the negatively charged electroactive species, but do not show significant response to redox active cations such as Co(phen)33+/2+ or Ru(NH3)63+/2+. Detailed study of the response at pH<5 to the Fe(CN)63−/4− couple has been made. Rotating disk studies and potential step chronoamperometry establish charge transport through the polymer as the rate limiting step for Fe(CN)64− oxidation at modified surfaces with Γpy≥10−7 mol/cm2. The limiting current at a rotating disk electrode increases with ionic strength over the range of μ=0.4 M to μ=1.4 M. The diffusion coefficient for charge transport within the polymer loaded with Fe(CN)64− is DE=9×10−9 cm2/s, in pH 2.5, μ=0.4 M ClCH2COO−, 0.5 M KCl solution.
Formal Models of International Institutions

The past three decades have witnessed the development of a rich literature that applies the formal tools of game theory to understanding international cooperation and international institutions. We divide this literature into three “generations” of scholarship. With a few notable exceptions, the first generation used very simple models—2×2 normal form games—to understand why states need to cooperate and why they comply with their cooperative agreements under conditions of anarchy. This first generation unfortunately bogged down in the neorealist–neoliberal debate. Second-generation scholars began to use tailor-made models to address the neorealist–neoliberal debate and to turn to new questions, such as how international agreements are created and how domestic political divisions affect international cooperation. With answers to the key questions of how international agreements are created and complied with, third-generation scholars could turn to increasingly refined models to answer specific questions ab...
Risk factors for drug dependence among out-patients on opioid therapy in a large US health-care system.

Aims Ourstudysoughttoassesstheprevalenceof andriskfactorsforopioiddrugdependenceamongout-patientson long-term opioid therapy in a large health-care system. Methods Using electronic health records, we identified out-patients receiving 4+ physician orders for opioid therapy in the past 12 months for non-cancer pain within a large US health-care system. We completed diagnostic interviews with 705 of these patients to identify opioid use disorders and assess risk factors. Results Preliminary analyses suggested that current opioid dependence might be as high as 26% (95% confidence interval (CI) = 22.0-29.9) among the patients studied. Logistic regressions indicated that current dependence was associated with variables often in the medical record, including age <65 (odds ratio (OR) = 2.33, P = 0.001), opioid abuse history (OR = 3.81, P < 0.001), high dependence severity (OR = 1.85, P = 0.001), major depression (OR = 1.29, P = 0.022) and psychotropic medication use (OR = 1.73, P = 0.006). Four variables combined (age, depression, psychotropic medications and pain impairment) predicted increased risk for current dependence, compared to those without these factors (OR = 8.01, P < 0.001). Knowing that the patient also had a history of severe dependence and opioid abuse increased this risk substantially (OR = 56.36, P < 0.001). Conclusion Opioid misuse and dependence among prescription opioid patients in the United States may be higher than expected. A small number of factors, many documented in the medical record, predicted opioid dependence among the out-patients studied. These preliminary findings should be useful in future research efforts.
Inference of Link Delay in Communication Networks

This paper studies the feasibility and algorithms for inferring the delay at each link in a communication network based on a large number of end-to-end measurements. The restriction is that we are not allowed to measure directly on each link and can only observe the route delays. It is assumed that we have considerable flexibility in choosing which routes to measure. We investigate two different cases: 1) each link delay is a constant and 2) each link delay is modeled as a random variable from a family of distributions with unknown parameters. We will answer whether such indirect inference is possible at all, and when possible, how it can be carried out. The emphasis is on developing the maximum-likelihood estimators for scenario 2) when the link delays are modeled by exponential random variables or mixtures of exponentials. We have derived solutions based on the EM algorithm and demonstrated that, even though they do not necessarily reflect the true model parameters, they do seem to maximize the likelihood in most cases and that the resulting probability density functions match the true functions on regions where the probability mass concentrates
Low O2-induced changes in pH and energy charge in pear fruit tissue☆

Pear (Pyrus communis L. cv. 'Bartlett') fruit were stored at 0°C for 2 or 4 weeks and subsequently ripened in air at 20°C or treated for 4 days with 0.25% 0 2 at 20°C before transfer to air for ripening. The juice pH (indicator of vacuolar pH) of air-treated fruit decreased slightly with ripening. Exposure to 0.25% 0 2 resulted in higher juice pH during the treatment and after transfer to air. Pear fruit discs, after 10 h aging, were also kept in air or 0.25% 02 at 20°C for 2 days and their 31p-NMR spectra obtained. The 0.25% O2-treated discs had higher cytoplasmic Pi (relative to the vacuolar Pi), had about 0.4 pH units lower cytosolic pH and lower ATP/ADP ratio indicating lower energy charge. The above changes could alter the in vivo activity of a number of respiratory enzymes in fruit subjected to hypoxic treatment.
Granzyme A Cleaves a Mitochondrial Complex I Protein to Initiate Caspase-Independent Cell Death

The killer lymphocyte protease granzyme A (GzmA) triggers caspase-independent target cell death with morphological features of apoptosis. We previously showed that GzmA acts directly on mitochondria to generate reactive oxygen species (ROS) and disrupt the transmembrane potential (DeltaPsi(m)) but does not permeabilize the mitochondrial outer membrane. Mitochondrial damage is critical to GzmA-induced cell death since cells treated with superoxide scavengers are resistant to GzmA. Here we find that GzmA accesses the mitochondrial matrix to cleave the complex I protein NDUFS3, an iron-sulfur subunit of the NADH:ubiquinone oxidoreductase complex I, after Lys56 to interfere with NADH oxidation and generate superoxide anions. Target cells expressing a cleavage site mutant of NDUFS3 are resistant to GzmA-mediated cell death but remain sensitive to GzmB.
On Doing the Decision: Effects of Active versus Passive Choice on Commitment and Self-Perception

Two studies demonstrate that making a volunteer decision by doing something results in more commitment to it than making the identical decision by doing nothing. Undergraduates were asked to volunteer for a university committee (Study l a) or a sex and AIDS awareness education project (Study 2) and indicated their choice either by affirming it on two items or by skippping two items that affirmed the opposite choice. Subjects who responded actively were more extreme in the degree of their decision than passive respondents. This effect persevered over 6 weeks (Study lb) and had behavioral consequences (Study 2). Attributional analyses in both studies suggest that active and passive choice may result in unique construals of oneself and of the decision: Active agreement results in citing more types of reasons for one's decision, and active refusal heightens one's perceived resistance to social influence.
Modeling crown structural responses to competing vegetation control, thinning, fertilization, and Swiss needle cast in coastal Douglas-fir of the Pacific Northwest, USA.

Crown structure is a key variable influencing stand productivity, but its reported response to various stand factors has varied. This can be partially attributed tolack of a unified studyon crown responseto intensive management or standhealth.In this analysis of severalcoastal Douglasfir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) branch datasets, a significant treatment effect of fertilization, thinning, pre-commercial thinning, varying levels of vegetation control, and intensity of a foliar disease (Swiss needle cast, caused by Phaeocryptopus gaeumannii (T. Rohde) Petr.) were all found to influence several key crown structural attributes. Maximum branch size and total and non-foliated crown radii were found to be the most dynamic and sensitive crown variables to the various stand factors as no treatment effects were found for the number of branches within an annual segment or branch angle. When the data sets were combined and used to develop a single predictive equation, treatment effects were largely accounted for by changes in bole and crown size as mean bias was relatively low despite the large range in tree ages examined (4‐450 years at breast height). While crown structure is highly variable and sensitive to a variety of stand factors, general empirical equations perform quite well and should be better integrated into models of forest growth and yield. # 2007 Elsevier B.V. All rights reserved.
The Frictional Behavior of Thin Halide Films on Iron

The frictional behavior of thin (< 1 μ m) sodium chloride, potassium chloride, and potassium iodide films deposited onto iron has been measured in ultrahigh vacuum. It has been shown previously that the friction coefficient decreases from the value for clean iron (∼2) to a minimum when the surface is covered by a monolayer film, and this is referred to as regime one. A second regime is identified in this work for films up to 0.3 μ m thick, where the friction coefficient increases with film thickness due to the increased contact area with the rough tribopin. The friction coefficient in this regime obeys Amontons' law. A third regime is found for films thicker than 0.3 μ m when the pin is completely supported by the film. Here, the contact behaves elastically, leading to a friction coefficient that varies as ( ). Amontons' law is no longer obeyed in this regime where now the friction coefficient is proportional to 1/ ).
Wavelength-scale functional waveguide mode conversion

A new type of field transformation mechanism is introduced that employs compact synthesized irregular waveguide structures. Results from a microwave experiment are given. Fabrication for optical applications using a lift-off process is proposed.