cssi/SciSciGPT-SciSciNet huggingface dataset:
Hypoxic pulmonary vasoconstriction and pulmonary artery tissue cytokine expression are mediated by protein kinase C

Abstract Background. Pulmonary arteries exhibit a marked vasoconstriction when exposed to hypoxic conditions. Although this may be an adaptive response to match lung ventilation with perfusion, the potential consequences of sustained pulmonary vasoconstriction include pulmonary hypertension and right heart failure. The concomitant production of proinflammatory mediators by the pulmonary artery itself may exacerbate acute increases in pulmonary vascular resistance. We hypothesized that acute hypoxia causes pulmonary arterial contraction and increases the pulmonary artery tissue expression of proinflammatory cytokines via a protein kinase C (PKC) mediated mechanism. Methods. Isometric force displacement was measured in isolated rat pulmonary artery rings during hypoxia (95% N2/5% CO2, pO2 = 30–35 mmHg) in the presence and absence of the protein kinase C inhibitor chelerythrine (1 μmol/L). Following 60 min of hypoxia, pulmonary artery rings were subjected to mRNA analysis for TNF-μ, IL-1β, and iNOS via RT-PCR. Data were analyzed using two-way analysis of variance (ANOVA) with post-hoc Bonferonni test or unpaired t tests with alpha level less than 0.05 considered statistically significant. Results. Hypoxia caused a biphasic contraction: an early and delayed contraction which occurred 1–3 and 15–20 min, respectively, after the onset of hypoxia. Hypoxic pulmonary artery tissue had increased expression of TNF-μ, IL-1β, and iNOS mRNA compared to normoxic controls. PKC inhibition significantly (P
Evaluating software for communities using social affordances

In this paper we discuss the problems faced when building software for communities. In particular, we introduce the formative evaluation method that emerged while developing two social network sites (SNSs). We acknowledge that the success of software for communities is due, in part, to the network effect, which is difficult to predict. We also acknowledge that traditional usability (e.g., individual user performance) is required, but not sufficient, for the success of a social network. We hypothesize that a missing piece of current evaluations are the social affordances provided by the system and how well they encourage users into social action. In this paper we present the rationale behind our evaluation, two examples of the evaluation, and discuss the evaluation's utility and future work.
Intragenic Domains of Strand-specific Repair inEscherichia coli

Abstract Heterogeneity of DNA repair has been observed at different levels of genomic organization, including chromatin domains, expressed genes and DNA strands. If heterogeneity also existed intragenically, it could reveal fine details of the excision repair mechanismin vivo.Here we measure the frequency of UV-induced cyclobutane pyrimidine dimers at individual nucleotides within defined portions of twoEscherichia coligenes,laclandlacZ, at various times after irradiation. Two domains of differential repair rates were apparent, with repair being slow at nucleotides adjacent to the transcription start sites. InlacZ, the domain of faster repair began 32 bases downstream of the transcription start site and required themfdgene. Sincemfdcodes for a transcription-repair coupling factor, this transcription-coupled repair system evidently becomes operative downstream of the initiation complex regionin vivo.Unexpectedly, however, (1) anmfdmutation reduced repair in the downstream domain even when transcription was at a very low level and (2) induction oflacZtranscription with isopropyl-β- d -thiogalactoside overcame this reduction. Evidently, the Mfd transcription-repair coupling factor is required for basal levels of strand-specific repair in this gene, but induced levels of repair are related to transcription through another mechanism.
Unorganized loan markets and monetary policy instruments

Abstract The paper uses a portfolio balance model to examine the relationship between monetary policy instruments and the unorganized loan rate. Predicting the direction of the change in this rate as a result of varying a policy instrument is important, since this rate is one channel through which a change in a policy instrument transmits to real activity, and since the demand side of the money market is partially re-equilibrated through this change. Studies have not clearly emphasized the relationship between each of the policy instruments and this rate. The findings depart in some cases from existing studies and shed more light on the relationships among policy instruments, monetary aggregates and real activity.
Management of cancer of the lip

The most frequent malignancy related to the lips is squamous cell carcinoma (95%), with the lower lip more commonly involved relative to the upper lip (90%:10%). 1 Typically, squamous cell carcinoma originates in the red lip (mucosa), whereas basal cell carcinoma originates in the white lip (skin). Unlike other squamous cell carcinomas of the upper aerodigestive tract, squamous cell carcinoma of the lip is thought to be related to sun exposure. Management of T1 and T2 squamous cell carcinoma of the lip typically involves complete surgical excision with postoperative radiation therapy used in more advanced stage lesions. Management of the neck is controversial, particularly with respect to the N0 neck. However, the risk of cervical metastasis is directly related to tumor size. Clinically, positive cervical node metastasis is managed with neck dissection. Elective dissection of the N0 neck is indicated in large T2, T3, and T4 lesions, as well as in recurrent primary cancers. The reader is directed to other sources for further review of management of cervical lymph nodes. 2 Treatment of carcinoma of the lip involves not only surgical resection with oncologically appropriate margins but also reconstruction of the lip to allow for satisfactory posttreatment rehabilitation. Lips function to dynamically provide for oral competence during the oral phase of swallowing. The lips also play an important role in emotional and verbal communication while esthetically serving as a focal point that defines an individual’s unique facial identity. The elements of successful reconstruction of the lip require satisfactory function while at the same time providing acceptable cosmesis. Reconstruction of the lip was described as long ago as 3000 BC and has evolved to include techniques in free tissue transfer. 3,4 The focus of this article is functional local flap reconstruction of the lip as related to acquired defects resulting from surgical extirpation of cancer associated with the lips. Anatomy and general considerations
Racial Prejudice, Belief Similarity, and Human Aggression

Summary Out of 66 undergraduates administered a scale designed to measure racial prejudice, 16 male Caucasians scoring above the median and 16 male Caucasians scoring below the median later interacted in a competition situation with an attitudinally similar or an attitudinally dissimilar black stimulus person. The competition situation was such that the Ss had the opportunity to aggress against their opponent using electric shock. The results indicated that highly prejudiced attitudes were related to high aggression scores. It was also observed that the attitudinal similarity variable interacted with the prejudice variable during the initial stages of the aggressive interaction.
Treatment Of Recurrent Juxtafoveal Subretinal Neovascular Membranes with Krypton Red Laser Photocoagulation

Abstract Thirty-seven eyes initially treated with argon blue-green, argon green, or krypton red laser photocoagulation demonstrated a recurrent subretinal neovascular membrane (SRNVM) at the edge of the treatment scar extending into the foveal avascular zone and were retreated with krypton red laser photocoagulation. The subretinal neovascular membrane was due to the presumed ocular histoplasmosis syndrome (POHS) in 10 eyes, aging macular choroidal degeneration (AMCD) in 22 eyes, and miscellaneous causes in five eyes. Anatomic success, defined as complete obliteration of the recurrent SRNVM, was achieved in 26 eyes (70%). When compared to pretreatment visual acuities, 23 of 37 eyes (62.2%) had stable or improved postoperative visual acuities during the follow-up period. Twenty-six eyes were retreated one time; nine eyes required two retreatments; and two eyes required three retreatments. Final visual results showed visual acuity ≥20/40 in 7 eyes (18.9%); visual acuity ≥20/80 in 16 eyes (43.8%); visual acuity ≥20/100 in 19 eyes (51.4%); visual acuity ≥20/200 in 27 eyes (73%); and visual acuity ≥20/400 in 34 eyes (91.9%).
Effects of season, rainfall, and hydrogeomorphic setting on mangrove tree growth in Micronesia

Seasonal patterns of tree growth are often related to rainfall, temperature, and relative moisture regimes. We asked whether diameter growth of mangrove trees in Micronesia, where seasonal changes are minimal, is continuous throughout a year or conforms to an annual cycle. We installed dendrometer bands on Sonneratia alba and Bruguiera gymnorrhiza trees growing naturally within mangrove swamps on the islands of Kosrae, Federated States of Micronesia (FSM), Pohnpei, FSM, and Butaritari, Republic of Kiribati, in the eastern Caroline Islands of the western Pacific Ocean. Trees were remeasured monthly or quarterly for as long as 6 yr. Annual mean individual tree basal area increments ranged from 7.0 to 79.6 cm 2 /yr for all S. alba trees and from 4.8 to 27.4 cm 2 /yr for all B. gymnorrhiza trees from Micronesian high islands. Diameter increment for S. alba on Butaritari Atoll was lower at 7.8 cm 2 /yr for the one year measured. Growth rates differed significantly by hydrogeomorphic zone. Riverine and interior zones maintained up to seven times the annual diameter growth rate of fringe forests, though not on Pohnpei, where basal area increments for both S. alba and B. gymnorrhiza were approximately 1.5 times greater in the fringe zone than in the interior zone. Time-series modeling indicated that there were no consistent and statistically significant annual diameter growth patterns. Although rainfall has some seasonably in some years on Kosrae and Pohnpei and overall growth of mangroves was sometimes related positively to quarterly rainfall depths, seasonal diameter growth patterns were not distinctive. A reduced chance of moisture-related stress in high-rainfall, wetland environments may serve to buffer growth of Micronesian mangroves from climatic extremes.
Emotions, Autonomy, and Decision-Making Capacity

Mackenzie and Watts (2011) describe reactive emotional states including “emotion–belief complexes” (Halpern 2010) as disrupting valuing, and rightfully express concern about judging patients’ diver...
Information processing speed in patients with multiple sclerosis

We have recently proposed that the cognitive deficits of patients with multiple sclerosis (MS) share numerous characteristics associated with the syndrome of subcortical dementia. One such characteristic, slowness of mental processing, was evaluated in the present study. Thirty-six MS patients were compared to 26 normal controls of equivalent age, education, and verbal intelligence on the Sternberg memory scanning test. As anticipated, the motor-involved MS patients had an overall slower reaction time than did controls. Their scanning rate, a measure of pure cognitive speed, was also significantly slower than controls. These results suggest that MS patients exhibit a slowing of mental processing independent of motor involvement.
Experience in the Use of a Digital Computer for Predicting Steam-Turbine Performance

This paper describes a number of programmes for digital computers that have been developed by the authors' firm to eliminate many of the tedious hand calculations which are encountered in the preliminary stages of steam-turbine and condenser design.By their use a considerable amount of the designers' time is saved and fatigue is reduced. These programmes also eliminate mistakes and inaccuracies which may occur in long calculations made by hand.The programmes described have been chosen as being representative of the range of programmes used in preliminary turbine design and optimization and are as follows:a programme to enable steam properties to be calculated, based on the formulae given in the Keenan and Keyes Steam Tables;a programme which can be used to determine the efficiency of small industrial turbines;a feed-heating programme which will carry out the calculations necessary to determine the preliminary energy balance for a feed-heating cycle;a detailed energy-balance programme incorporating turbine...
Simultaneous prediction of Cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of synthetic waters

A model was developed to simultaneously assess Cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of synthetic solutions in batch and flow-through reactors. The model incorporated 65 elementary chemical reactions involved in the decomposition of ozone and the oxidation of bromine species and their corresponding rate or equilibrium constants reported in the literature. Ozonation experiments were performed with a laboratory-scale batch reactor to evaluate the model with respect to the rate of ozone decomposition and bromate formation. The model was found to provide a good representation of experimental results when the ozone decomposition initiation reaction with hydroxide ion was assumed to produce superoxide radical instead of the alternatively proposed product hydrogen peroxide. The model was further developed to simulate the performance of a flow-through bubble-diffuser reactor with an external recirculation line. Each compartment of the reactor (bubble column and recirculation line) was assumed to behave as a plug flow reactor as supported by tracer test results, and an empirical correlation was used to represent the rate of ozone gas transfer in the bubble column. Model predictions of the performance of the flow-through ozone bubble-diffuser contactor were in good agreement with experimental results obtained for bromate formation and C. parvum oocyst inactivation under all conditions investigated. Additional model simulations revealed that hydrodynamic conditions had a more pronounced effect on C. parvum oocyst inactivation than on bromate formation. In contrast, pH had a strong effect on bromate formation without affecting the inactivation efficiency of C. parvum oocysts for a given level of exposure to ozone. These findings suggested that bromate formation could be minimized while achieving target inactivation levels for C. parvum oocysts by designing ozone reactors with hydrodynamic conditions approaching that of an ideal plug flow reactor and by lowering the pH of the target water.
Relationship between plasma and whole blood theophylline concentration in neonates

DECREASED and variable clearance of theophylline in premature infants has led to the recommendation that serum concentrations of this drug be monitored when it is used for control of apnea. 1 Theophylline concentration data have been reported as whole blood concentration by some researchers '~. 3 and as serum or plasma concentration by others?. ~ Schack and Waxier ~ have reported that red blood cells do not apparently contain theophylline. If this is the case, the hemolysis of samples prior to analysis of whole blood theophylline concentration would produce a dilution of theophylline present in the plasma, the magnitude of which would be proportional to the hematocrit of the sample. As hematocrits are frequently elevated and vary markedly from patient to patient in newborn infants, the relationship between whole blood and plasma theophylline concentration would be expected to be extremely variable. The purpose of this study was to determine this relationship in premature neonates who were receiving theophylline for the treatment of apnea.
Pulpal Pain Diagnosis—A Review

Evidence gathered from our studies and the work of others appears to support the presence of two distinct nerve pain pathways in the dental pulp, represented by fast conducting A-delta and slow conducting C-fibers. Each of these types of fibers has different pain characteristics: A-delta fibers evoke a rapid, sharp, lancinating pain reaction, and C-fibers cause a slow, dull, crawling pain. Pain response thresholds vary in different regions of the tooth, and thermal, osmotic, ionic, and electric stimuli involve different mechanisms to provoke nerve excitation of the dental pulp. Evidence also points to the fact that the incidence of pain increases as the histopathosis worsens. On interrogation, patients who manifest severe or referred pain almost always give a previous history of pain in the tooth with the ache. Eighty percent of patients who give a previous history of pain manifest histopathologic evidence of chronic partial pulpitis with partial necrosis, the untreatable category, for which endodontics or extraction is indicated. The other 20% exhibit histopathosis of the pulp with slight inflammation to chronic partial pulpitis without necrosis, a treatable category. Clinically, one can determine the degree of pulp histopathosis by asking the patient about a previous history of pain in the involved tooth. This history of previous pain adds another dimension in diagnosis for the clinician as to whether the painful pulpitis is reversible. This information also aids in referred pain localization.
A monte carlo study of the effects of grouping on the analysis of censored survival data

In certain survival studies the percentage of right-hand single censoring and the frequency of survival assessment, which results in the grouping of otherwise distinct failure times, is under experimental control. It is important to determine the consequences of the use of the Peto-Breslow approximate likelihood function in the analysis of studies with grouped and censored observation. A Monte Carlo study was performed to simulate the response surface analysis of data generated under the assumption of Cox's proportional hazard model. Fortuitous reductions in the mean squared error of the model parameters with slight grouping and censoring are observed.
A tale of two systems: Pathology resident recruitment in and out of the National Resident Matching Program.

The recruitment of most first-year pathology residents currently occurs via 2 systems: the National Resident Matching Program (NRMP), known as the Match, and an underground Out-of-Match process. Out-of-Match recruitment is not a sanctioned option for American medical school seniors. Recent declines in American seniors choosing pathology has intensified pressures to recruit good international medical graduates (IMGs). Pressures by programs on IMGs and by IMGs on programs result in the Out-of-Match recruitment of many IMGs who initially enroll in the NRMP. IMGs may be offered unsolicited Out-of-Match positions with a decision deadline even though they are still interviewing. Some are told if they decline an offer, they will not be ranked by that program in the NRMP process. To enhance apparent recruitment success, programs also feel pressured to participate in the Out-of-Match process, as well as offer positions before they have interviewed all applicants. Coercion of applicants and programs contravenes the spirit of the NRMP, compromises the ability of applicants and programs to best match needs, taints constructive interactions among program directors, and does not enhance pathology's image among applicants or in the broader medical community.
Dial and see: tackling the voice menu navigation problem with cross-device user experience integration

IVR (interactive voice response) menu navigation has long been recognized as a frustrating interaction experience. We propose an IM-based system that sends a coordinated visual IVR menu to the caller's computer screen. The visual menu is updated in real time in response to the caller's actions. With this automatically opened supplementary channel, callers can take advantages of different modalities over different devices and interact with the IVR system with the ease of graphical menu selection. Our approach of utilizing existing network infrastructure to pinpoint the caller's virtual location and coordinating multiple devices and multiple channels based on users' ID registration can also be more generally applied to create integrated user experiences across a group of devices.
Trends in mixed signal RF and integrated microsystems

Integrated mixed signal electronics combining analog, digital and radio frequency circuits is being used to realize beyond-leading-edge components and systems on a chip with revolutionary performance and high levels of functionality. This talk will provide an overview of integrated microsystem development and associated material and device technology. Specific examples will include reconfigurable radio frequency circuit and device technology, heterogeneous integrated circuits, multiresolution spectral sensors, intelligent microsystems and integrated microsystems for digital beamformers. This technology is pushing the limits of conventional scaling, integration, linearity and power dissipation and is changing the paradigm of a variety of systems by making it possible to improve data throughput and connectivity by enabling autonomous reconfigurability, spectral and temporal agility and adaptive behaviour.
Noxious thermal stimulation of c-fos activity induced in rat lumbar spinal cord is reduced by AP-5 but not by glycine.

Abstract The effects of intrathecal administration of NMDA ( N -methyl- d -aspartic acid) receptor antagonist AP-5 (2-Amino-5-phosphonopentanoic acid), a competitive and specific NMDA antagonist, and glycine on the neuronal expression of c-fos protein (Fos) in the dorsal neurons lumbar segments four and five were studied after noxious heat stimulation. Heat (52°C, 3 s per application, repeated 10 times) was applied to the hindpaws of rats. NMDA receptor antagonist AP-5 (0.1 mmol/10 ml, i.t.) suppressed the noxious heat-induced Fos immunoreactivity by 65% as compared to animals pre-treated with saline. In contrast, glycine (0.1 μ mol/10 μ l, it.) did not influence Fos expression induced by the noxious heat stimulation. This study suggests that excitatory amino acids, e.g. glutamate but not the inhibitory aminos acid, glycine, plays a role in thermal nociception which in turn is mediated, in part, by c-fos activity.
Numerically testing phenomenological models for conductance of a solid-state nanopore

The ionic conductance of a solid-state nanopore plays an important role in analyzing biomolecules transported through the pore. The phenomenological pore-conductance is assumed to be a sum of three contributions: bulk, surface (for a charged nanopore) and access ones. Despite being commonly used, phenomenological results were not rigorously derived in theory and their accuracies have not been tested yet. By carrying out numerical modeling on the nanopore conductance, I show that both the ion concentration and the surface charge can affect the accuracy. For a charged solid-state nanopore solvated in an intermediate-ion-concentration electrolyte (e.g. 50 mM), the phenomenological result can be substantially larger than the numerically calculated one. The criteria for properly applying phenomenological results are provided.
First-Order Conformal Invariants

The Theme of this section is the following: Suppose you find yourself on a plane domain, with only a restricted logic at your disposal; how closely can you determine which domain you are on—up to conformal equivalence? This leads to a study of a system of conformal invariants, the first-order conformal invariants (FOCI), which are obtained from the elementary properties of the algebra (or ring) of analytic functions on plane domains. Although the formal definition of FOCI is given in the terminology of mathematical logic, these invariants are nonetheless all included within the framework of classical function theory. Each of the FOCI corresponds to an elementary assertion about analytic functions that can be understood without any knowledge of mathematical logic.
Promises of PAR-1 inhibition in acute coronary syndrome.

Platelet activation is a key process in the pathogenesis of acute coronary syndromes (ACS). Of the many triggers involved in this process, three are presumed to be critical: thromboxane A2 (TBXA2) via the TBXA2 receptor, adenosine diphosphate via the P2Y12 receptor, and thrombin via the protease-activated receptor (PAR)-1. Despite the effective inhibition of the first two pathways with aspirin and an expanding family of P2Y12 inhibitors, the incidence of recurrent ischemic events remains high after ACS. PAR-1 inhibitors are a novel class of antiplatelet agents that inhibit thrombin-mediated platelet activation. Preclinical data and phase 2 clinical trials in patients with stable and unstable coronary disease support the potential of these compounds to improve clinical outcome. In this review we discuss the rationale for developing this novel class of agents with a focus on the two compounds in most advanced clinical development, vorapaxar (SCH 530348) and atopaxar (E5555).
The structure of opalinids, as revealed by the technique of micro‐incineration

Opalinids from the rectum of Rana pipiens were isolated in large numbers and fixed in a mixture of nine parts of absolute alcohol and one part of neutral formalin. These were embedded in paraffin and incinerated according to the technique of Policard. Examination of the preparations by dark-field illumination showed that the micro-incinerated protozoa retained their distinctive morphological and cytological characters, for the mineral ash had the same topographical distribution as the cell inclusions in the control stained preparations. The coarse vegetative granules of the cytoplasm were preserved as distinct masses of ash which corresponded exactly to these bodies in the control preparations. The structure of the myonemata and the cilia was perfectly preserved. The chromatin material of the nucleus, more or less abundant, left little or no ash, which is quite in contrast to the findings of Scott with regard to amphibian and mammalian nuclei.
Theories of the Earth's Magnetism

The earth's core may be assumed to consist of fluid metal surrounding a solid inner core which probably contains a source of heat to drive convection, but it is not possible at present to select between various possible types of convective motion in the fluid core. Types considered are characterized by some sort of radial flow streams and a tendency for the fluid to rotate on the average more rapidly near the axis to conserve angular momentum during the circulation. Though the actual flow may be quite complicated, proposed mechanisms for generating a terrestrial magnetic field are considered for some oversimplified flow patterns in an attempt to indicate what features of the flow may provide the most important possibilities for field generation. It is suggested that, without a field to absorb the energy, the flow would be accelerated indefinitely and would evolve through a succession of flow patterns, some of which would be expected to have the properties to generate a field capable of preventing further acceleration and prolonging the status quo, thus making it likely that the earth should have a field.The generating mechanisms discussed include two induction theories, the dynamo theory of Elsasser and Bullard, which is discussed at length both in terms of velocity-current systems portrayed by elaborate models and in hydromagnetic terms, and the "twisted-kink" theory of Alv\`en which is discussed only hydromagnetically. Each of these theories depends on amplifying an initial stray magnetic field up to a point where it dissipates all of the available energy, and is at least in this respect analogous to a conventional electrical generator but without a ferromagnetic core. Other mechanisms discussed depend either on the thermoelectric effect with junctions at the core-mantle interface or on a combination of thermoelectric and Hall effects in the core and mantle.If the convective flow is rather irregular, the observed slow westward drift of the detailed pattern of the earth's field is attributed to the vanishing of the total torque on the core by the magnetic field threading through the core and mantle, as a result of an eastward drag on the outer part of the core rotating more slowly in space and a westward drag on the more rapidly rotating part of the core near the axis, with the presumption that the observed magnetic pattern is characteristic of the westward-drifting outer part. If the flow instead involves a jet stream, the flow in the jet may under some circumstances be expected to be eastward for reasons comparable to temperate-zone meteorology, so the magnetic field should exert a westward drag on it leading to the westward drift of the flow pattern.
Service orientation for contact employees in Korean casual-dining restaurants.

Abstract The purposes of this study were to validate Groves’ (Perceived service orientation of restaurant employees, unpublished doctoral dissertation, Kansas State University, Manhattan, KS, 1992) restaurant service orientation scale, to examine contact employees’ service orientation in Korean casual-dining restaurants, and to investigate the effect of employee characteristic variables on service orientation. Self-administered questionnaires were distributed to waitpersons and bartenders working for a casual-dining chain in Seoul, Korea. Factor analysis indicated that Groves’ scale had four dimensions (organizational support, customer focus, service under pressure, and prior customer relationship) rather than three. The additional factor of prior customer relationship was determined to be a subdimension of the customer-focus factor. Age, gender, marriage, and education did not have significant impacts on service orientation. However, employees with a longer length of service and those in supervisory positions displayed a higher degree of service orientation. Lastly, employees in each unit of the chain displayed significant differences in service orientation.
Carcinogenic and mutagenic properties of chemicals in drinking water.

Abstract Isolated cases of careless handling of industrial and domestic waste has lead to a wide variety of dangerous chemicals being inadvertently introduced into drinking water. However, chemicals with established carcinogenic and mutagenic properties that occur with a high frequency and in multiple locations are limited in number. To date, the chief offenders have been chemicals of relatively low carcinogenic potency. Some of the more common chemicals are formed as by-products of disinfection. The latter process is generally regarded as essential to the production of a “microbiologically safe” drinking water. Consequently, any reductions in what may be a relatively small carcinogenic risk must be balanced against a potential for a higher frequency of waterborne infectious disease. The results of recent toxicological investigations will be reviewed to place the potential carcinogenic and mutagenic hazards frequently associated with drinking water into perspective. First, evidence for the carcinogenicity of certain volatile organic compounds such as trichloroethylene, tetrachloroethylene and carbon tetrachloride is considered. Second, the carcinogenic activity that can be ascribed to various by-products of chlorination is reviewed in some detail. Finally, recent evidence that other chemicals derived from the treatment and distribution of drinking water is highlighted as an area requiring move systematic attention.
Relative bounded cohomology

Abstract In this paper, we provide the algebraic foundations to the theory of relative bounded cohomology. In particular, we prove that the relative bounded cohomology of spaces depends only on their fundamental groups. We also prove Gromov's Equivalence theorem and Relative mapping theorem for relative bounded cohomology, stated by Gromov without proofs in [M. Gromov, Publ. Math. IHES 56 (1982) 5–100].
The hands-free telephone

AMONG THE UTILITIES which contribute to good standard of living, the telephone stands in prominence, playing a vital role in the activities of many people. The ease of communication provided by the telephone aids and promotes progress in every phase of human endeavor. Since its invention much work has been done to improve the telephone and to make it adaptable for new communication services. Recent advances in the electronics art, resulting in component improvement and miniaturization, provide powerful means for furthering the improvement of the telephone. One example of telephone adaptation for rendering a novel service is the development of a hands-free telephone, also known as a loudspeaking telephone.
Pharmacological investigation of the bioluminescence signaling pathway of the dinoflagellate Lingulodinium polyedrum: evidence for the role of stretch-activated ion channels.

Dinoflagellate bioluminescence serves as a whole-cell reporter of mechanical stress, which activates a signaling pathway that appears to involve the opening of voltage-sensitive ion channels and release of calcium from intracellular stores. However, little else is known about the initial signaling events that facilitate the transduction of mechanical stimuli. In the present study using the red tide dinoflagellate Lingulodinium polyedrum (Stein) Dodge, two forms of dinoflagellate bioluminescence, mechanically stimulated and spontaneous flashes, were used as reporter systems to pharmacological treatments that targeted various predicted signaling events at the plasma membrane level of the signaling pathway. Pretreatment with 200 μM Gadolinium III (Gd(3+) ), a nonspecific blocker of stretch-activated and some voltage-gated ion channels, resulted in strong inhibition of both forms of bioluminescence. Pretreatment with 50 μM nifedipine, an inhibitor of L-type voltage-gated Ca(2+) channels that inhibits mechanically stimulated bioluminescence, did not inhibit spontaneous bioluminescence. Treatment with 1 mM benzyl alcohol, a membrane fluidizer, was very effective in stimulating bioluminescence. Benzyl alcohol-stimulated bioluminescence was inhibited by Gd(3+) but not by nifedipine, suggesting that its role is through stretch activation via a change in plasma membrane fluidity. These results are consistent with the presence of stretch-activated and voltage-gated ion channels in the bioluminescence mechanotransduction signaling pathway, with spontaneous flashing associated with a stretch-activated component at the plasma membrane.
Communities of Practice and the Mediation of Teachers' Responses to Standards-based Reform.

This paper evaluates the usefulness of a sociocultural approach for analyzing teachers’ responses to the professional learning demands of standards-based reform policies. A policy-oriented case study of the practice of six elementary teachers who worked in two high poverty schools in a demographically changing district in the state of Washington is summarized. Key findings of that study conclude that communities of teaching practice are sites for teacher learning and are mediators of teachers’ responses to standards-based reform. Characteristics of the communities of practice, including their relative strength and openness (to learning), influence the degree to which teachers work out negotiated and thoughtful responses to policy demands. The present paper discusses the efficacy of Wenger’s (1998) theory of learning for the study of policy to practice connections.
ARRHYTHMIAS AND SUDDEN DEATH IN HEART FAILURE

Survival of patients with heart failure has improved over the past decade due to advances in medical therapy. Sudden death continues to cause 20 to 50% of deaths. Ventricular arrhythmias are common in patients with heart failure. Ventricular hypertrophy, scars from prior myocardial infarction, sympathetic activation, and electrolyte abnormalities contribute. Some sudden deaths are due to bradyarrhythmias and electromechanical dissociation rather than ventricular arrhythmias. The risks and benefits of antiarrhythmic therapies continue to be defined. Class I antiarrhythmic drugs should be avoided due to proarrhythmic and negative inotropic effects that may increase mortality. For patients resuscitated from sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) amiodarone or an implantable cardioverter defibrillator (ICD) should be considered. ICDs markedly reduce sudden death in VT/VF survivors, but in advanced heart failure, this may not markedly extend survival. Catheter or surgical ablation can be considered for selected patients with bundle branch reentry VT or difficult to control monomorphic VT. For patients who have not had sustained VT/VF antiarrhythmic therapy should generally be avoided, but may benefit some high risk patients. Amiodarone may be beneficial in patients with advanced heart failure and rapid resting heart rates. ICDs may improve survival in selected survivors of myocardial infarction who have inducible VT.
Instantaneous dislocation velocities in iron at low temperature

Plasticity is a consequence of the motion of crystalline defects--dislocations--moving under the action of an applied stress, {sigma}. Their motion is resisted by other defects, impurities, and the crystal structure itself--the Peierls barrier. Also, dislocation motion is damped by phonons and by electrons. Measurement of instantaneous dislocation velocities, V{sub i}, during deformation, is a prerequisite to a full understanding of plasticity. What, then, determines the velocity of dislocations during plasticity? A method of measuring V{sub i} exploits the low temperature interaction of electrons with mobile dislocations in a magnetic field; low temperatures substantially eliminate phonon damping. This is the only method, the theory of which is given elsewhere, that measures V{sub i} in an ordinary tensile test. Given are measurements of V{sub i}(T) for iron single crystals.
Non-invasive imaging and analysis of cerebral ischemia in living rats using positron emission tomography with 18F-FDG.

Stroke is the third leading cause of death among Americans 65 years of age or older1. The quality of life for patients who suffer from a stroke fails to return to normal in a large majority of patients2, which is mainly due to current lack of clinical treatment for acute stroke. This necessitates understanding the physiological effects of cerebral ischemia on brain tissue over time and is a major area of active research. Towards this end, experimental progress has been made using rats as a preclinical model for stroke, particularly, using non-invasive methods such as 18F-fluorodeoxyglucose (FDG) coupled with Positron Emission Tomography (PET) imaging3,10,17. Here we present a strategy for inducing cerebral ischemia in rats by middle cerebral artery occlusion (MCAO) that mimics focal cerebral ischemia in humans, and imaging its effects over 24 hr using FDG-PET coupled with X-ray computed tomography (CT) with an Albira PET-CT instrument. A VOI template atlas was subsequently fused to the cerebral rat data to enable a unbiased analysis of the brain and its sub-regions4. In addition, a method for 3D visualization of the FDG-PET-CT time course is presented. In summary, we present a detailed protocol for initiating, quantifying, and visualizing an induced ischemic stroke event in a living Sprague-Dawley rat in three dimensions using FDG-PET.
Simple linear relationship between dry matter, specific gravity, and tissue specific gravity in a diploid potato breeding population

Two hundred clones were randomly selected in 1988 and in 1989 from a hybrid population ofSolanum phureja andSolanum stenotomum to determine the relationship between specific gravity (SG) and percent dry matter (%DM), and between tissue specific gravity (TSG) and %DM. The objectives were: (1) to determine the dry matter prediction equation for a diploid potato population, (2) to determine whether estimates of %DM and efficiency of selection for %DM could be improved by measuring TSG, and (3) to determine the influence of year on the estimates. In 1988 the prediction equation for the relationship between %DM and SG was %DM=198.71 (SG-191.30,r=0.85. Ranges and means for the variables were: (1) %DM: 16.99–32.67, mean 25.16; (2) SG: 1.054–1.122, mean 1.089. In 1989 the relationship of %DM and SG was predicted as %DM=194.46(SG)-187.53,r=0.87; whereas the relationship of %DM and TSG was predicted as %DM=196.77(TSG)-192.91,r=0.87. Ranges and means for the variables were: (1) %DM: 10.68–34.57, mean 21.32; (2) SG: 1.030–1.122, mean 1.074; (3) TSG: 1.046–1.141, mean 1.089. Slopes were not significantly different between any of the prediction equations, but intercepts were significantly different. Estimates of %DM were not improved by measuring TSG. Year did influence the relationship between %DM and SG.
Gender Bias in Skin Cancer: Role of Catalase Revealed

Sullivan et al. describe their finding that lower skin catalase activity in male as compared with female mice may be responsible for the increased skin carcinogenesis observed in UVB radiation–exposed male mice. This adds to the growing literature that points toward a gender bias in the pathogenesis of skin cancer. Delineating the events between UV exposure and carcinogenesis in relation to skin’s antioxidant activity will provide insight into disease progression, prognosis, and responses to therapy. If substantiated with further studies in humans, this information may aid in designing gender-specific preventive measures aimed at reversing immune suppression through targeting the altered redox status in UV-exposed individuals.
An erroneous glycosaminoglycan metabolism leads to corneal opacification in macular corneal dystrophy

Macular corneal dystrophy (MCD) is a rare, potentially blinding disease whose fundamental genetic defect and exact pathogenesis are yet to be elucidated. It is, however, an especially interesting pathology, which highlights how an erroneous glycosaminoglycan or proteoglycan metabolism can induce physical symptoms in a specific connective tissue. Based on immunochemical data, MCD is a heterogeneous condition, and at least two types of the disease have been identified. The cornea, cartilage, and serum from MCD type I patients all contain an unsulphated form of keratan sulphate. In contrast, these tissues contain normally sulphated keratan sulphate in MCD type II patients. A normal population of keratan sulphate proteoglycans (and chondroitin/dermatan sulphate proteoglycans) in the cornea seems to be a requirement of corneal transparency. However, a clinical diagnosis of MCD is unable to distinguish between the keratan sulphate positive and negative types of MCD. The histopathology of MCD is fairly well established, and various corneal aberrations—such as fibrillogranular and glycosaminoglycan deposits, abnormal diameter collagen, and collagen-free lacunae—result in a breakdown of the regular corneal architecture that presumably contributes to the subsequent corneal opacification.
On the uniform ADC bit precision and clip level computation for a Gaussian signal

The problem of computing the required bit precision of analog-to-digital converters is revisited with emphasis on Gaussian signals. We present two methods of analysis. The first method fixes the probability of overload and sets the dynamic range of the quantizer to accommodate the worst-case signal-to-quantization noise ratio (SQNR). The second method sets the clipping level of the quantizer to meet a desired overload distortion level, using knowledge of the input probability density function. New closed-form expressions relating the distortion-minimizing clip level of the uniform quantizer and the input bit rate are derived and shown to give remarkably close results to the optimum ones obtained using numerical iterative procedures devised elsewhere.
Domain decomposition in optimal boundary control of second order hyperbolic systems on 2-D networks

A method of decomposing the optimality system arising in optimal boundary control of hyperbolic systems of partial differential equations on 2-D networks into subproblems on individual elements of the network is presented.
Symmetry and control: spatially extended chaotic systems

In a recent paper [Phys. Rev. E 57 (1998) 1550] it was demonstrated that the symmetries of the evolution equation and the target state have a profound effect on controlling the chaotic behavior. In the present paper we extend these results to the cases of time-periodic target trajectories and inexact symmetries, and apply the developed formalism to the problem of controlling spatiotemporal chaos. We use the example of a lattice dynamical system in arbitrary spatial dimension to show that there exists an intimate relationship between the geometry of an extended system and the geometry of feedback control. © 2000 Elsevier Science B.V. All rights reserved.
Three-dimensional phase-field simulations of the effect of convection on free dendritic growth

Abstract Three-dimensional free dendritic growth of a pure material into an undercooled melt in the presence of fluid flow is investigated numerically using the phase-field method. Such computations are made possible by solving the Navier–Stokes equations for the flow and the energy equation for the heat transport on a grid that is twice as coarse as the grid for the phase-field equation. The effect of the flow on the upstream growing dendrite tip velocity and radius of curvature is investigated as a function of the imposed flow velocity, undercooling, crystalline anisotropy, and Prandtl number. The results are compared to available theories of dendritic growth with and without convection. The predicted growth Peclet numbers as a function of the flow Peclet number are in reasonable agreement with the theoretical predictions. The dendrite tip selection parameter is essentially independent of the flow velocity within the range studied, which is also in accordance with theory. The three-dimensional dendrite tip shape is found to be well fitted by the same universal scaling relation as without flow.
The role of model based control in robotics

The use of model-based control of industrial robots is discussed. Computer models of the robots and their operating environments are complemented with environmental sensing. This allows automatic programming of robot trajectories, hybrid force/position control, and computer assistance during manual operation. In addition, sensors detect error situations which may require operator attention prior to continued system operation. Computer models are also used to verify the validity of sensor data before the robotic system executes operations based upon those data. >
Collisional narrowing effects on spectral line shapes measured at high resolution.

The averaging effect of velocity-changing collisions reduces the Doppler broadening of isolated spectral lines and leads to one type of collisional narrowing. We present four collisionally narrowed profiles in standardized form using dimensionless parameters and estimate the quantitative effect of narrowing on the spectral line shape in terms of the magnitudes of these parameters. We show that a collisionally narrowed profile fitted by a Voigt function exhibits a characteristic signature on a plot of the residual errors in the fit. This provides a simple test for detectable narrowing effects. One of the simpler and better known models which includes collisional narrowing is the Galatry profile. We present sample plots of the residual errors resulting when theoretical profiles computed from other more elaborate models are fitted by a Galatry function.