cssi/SciSciGPT-SciSciNet huggingface dataset:
Ca2+ ions inhibit messenger ribonucleic acid degradation, but permit messenger ribonucleic acid transcription and translation in deoxyribonucleic acid-coupled systems from Escherichia coli.

Abstract DNA-directed formation of RNA and protein was compared in subcellular systems in the absence or presence of Ca2+ ions. In the absence of Ca2+, messenger RNA was unstable, and protein and RNA accumulation tended to stop after incubations of 10 to 15 min at 37°. In contrast, in the presence of Ca2+ mRNA was stabilized almost completely. As a result, the net accumulation of RNA and protein continued for 20 to 45 min at 37°, and could be 3-fold greater, even though the rates of formation are lower. The fate of the RNA in the presence and in the absence of Ca2+ was detailed after limitation of synthesis by rifampicin, in DNA-coupled systems modified from those of Lederman and Zubay (Lederman, M., and Zubay, G. (1967) Biochim. Biophys. Acta 149, 253) or Gold and Schweiger (Gold, L. M., and Schweiger, M. (1971) Methods Enzymol. 20, 537). In the presence of Ca2+, little or no acid-soluble material was released during 30 min from RNA formed on T4, Escherichia coli, φ80, or λDNAs, and T4-specific mRNA extracted at various times and analyzed by acrylamide gel electrophoresis showed no detectable cleavages to smaller sized chains. The implication that a number of ribonucleases are directly inhibited by Ca2+ ions was confirmed for two purified E. coli enzymes, the endonuclease RNase III and the exonuclease RNase II. Thus, Ca2+ ions provide an effective way to dissociate in vitro the physiological coupling of mRNA formation and translation from its degradation. In the absence of Ca2+, a number of features of mRNA metabolism in vivo could be reproduced. Chemical decay of E. coli and T4-specific mRNA was studied. As in vivo, decay of both types of mRNA was exponential. Also, the half-lives (2.25 min for E. coli and 4.45 min for T4 mRNA) were of the same magnitude and in the same ratio as in vivo. Furthermore, the response of mRNA metabolism to antibiotics was comparable to that in vivo; when protein synthesis was blocked by the addition of chloramphenicol, new mRNA was protected against decay, but when puromycin was used to block protein synthesis, mRNA still degraded rapidly.
Issues in Implementing a New Teacher Assessment System in a Large Urban School District: Results of a Qualitative Field Study.

This article presents the findings of the Professional Assessment and Comprehensive Evaluation System (PACES) Spring 2000 Fields Study in a large southeastern school district. PACES is a comprehensive, learner-centered, classroom-based system that is designed to provide teachers, administrators, and other educators with information useful for improving teaching and learning. PACES teaching and learning can take a variety of forms including: teacher self-assessment, assessment of written planning documents, collaborative conversations about teaching and learning, group assessments by teachers working together to share their views, and assessments resulting form one or more systematic classroom observations and professional conferences. During the 2000 Field Study, PACES was undergoing its first year of district-wide piloting. Semi-structured interview data were collected from 205 in-school personnel (teachers, administrators, and union stewards) at 24 different school sites. The results of the study provide valuable administrative insight into organizational change processes, issues of school culture and change, and reform and improvement of teacher assessment and evaluation practices. The article begins with a brief history and description of PACES. The details of the 1999–2000 school year pilot of PACES are then described. The methods used in the study are explained, including scholarship supporting the research methodology employed for the study. The results of the study are presented, followed by a set of recommendations that are designed to facilitate the successful implementation of a new teacher assessment system.
Development of a test protocol for evaluating EVA glove performance

Testing gloved hand performance involves work from several disciplines. Evaluations performed in the course of reenabling a disabled hand, designing a robotic end effector or master controller, or hard-suit design have all yielded relevant information, and, in most cases, produced performance test methods. Most times, these test methods have been primarily oriented toward their parent discipline. For space operations, a comparative test which would provide a way to quantify pressure glove and end effector performance would be useful in dividing tasks between humans and robots. Such a test would have to rely heavily on sensored measurement, as opposed to questionnaires, to produce relevant data. However, at some point human preference would have to be taken into account. This paper presents a methodology for evaluating gloved hand performance which attempts to respond to these issues. Glove testing of a prototype glove design using this method is described.
Voice Relative Fundamental Frequency Via Neck-Skin Acceleration in Individuals With Voice Disorders

Purpose This study investigated the use of neck-skin acceleration for relative fundamental frequency (RFF) analysis. Method Forty individuals with voice disorders associated with vocal hyperfunction and 20 age- and sex-matched control participants were recorded with a subglottal neck-surface accelerometer and a microphone while producing speech stimuli appropriate for RFF. Rater reliabilities, RFF means, and RFF standard deviations derived from the accelerometer were compared with those derived from the microphone. Results RFF estimated from the accelerometer had slightly higher intrarater reliability and identical interrater reliability compared with values estimated with the microphone. Although sensor type and the Vocal Cycle × Sensor and Vocal Cycle × Sensor × Group interactions showed significant effects on RFF means, the typical RFF pattern could be derived from either sensor. For both sensors, the RFF of individuals with vocal hyperfunction was lower than that of the controls. Sensor type and its i...
Laboratory Maintenance of Rickettsia rickettsii

This unit includes protocols for the laboratory maintenance of the obligate intracellular bacterium Rickettsia rickettsii, including propagation in mammalian cell cultures, as well as isolation, counting, and storage procedures. Regulations for working with R. rickettsii in biosafety level 3 containment are also discussed.
Readability of pediatric health materials for preventive dental care

Background This study examined the content and general readability of pediatric oral health education materials for parents of young children.
Low molecular weight RNAs of post-ribosomal particles: Evidence that the particulate 4-S RNAs comprise a differential population of transfer RNA

Abstract Low molecular weight, methylated RNA having the electrophoretic mobility of transfer RNA was isolated from 10- to 30-S particulate material of cultured Chinese hamster cell cytoplasm. The nature of the particulate 4-S RNA was investigated. It was found to be methylated to about the same extent as supernatant transfer RNA. Most of it was transfer RNA as judged by its acceptance of AMP from ATP in the presence of tRNA-CMP-AMP pyrophosphorylase or by detailed analysis of its methylated nucleoside composition. The particulate 4-S RNA did not accept amino acids for the formation of aminoacyl-tRNA to the extent of supernatant tRNA and chromatography of particulate 4-S RNA on benzoylated DEAE-cellulose showed a very different elution pattern from that of supernatant tRNA. We conclude that most of the particulate 4-S RNAs comprise a differential population of transfer RNA like material.
Investigation of 3-channel all-optical regeneration in a group-delay-managed nonlinear medium

We investigate three-channel performance of a stand-alone Mamyshev 2R regenerator based on Raman-assisted group-delay-managed medium. Our results indicate, for the first time to our knowledge, the feasibility of simultaneous regeneration of 100-GHz-spaced WDM channels.
Modeling the effect of trap levels on the optimum resistivity of silicon solar cells

Numerical studies were performed to determine the effect of different trap levels on the optimum resistivity required to produce high-efficiency solar cells from materials of varying initial quality. Lifetime decreases with the doping concentration due to Auger, band-to-band, and SRH (Shockley-Read-Hall) recombinations and shallow traps, make the SRH lifetime more sensitive to the doping density for the same initial lifetime in the undoped material. It was found that the optimum resistivity for high-efficiency cells depends on several factors including the initial lifetime, the trap level, the relationship between the trap and doping density and the injection level in the cell. For low initial lifetimes, around 10 mu s, the optimum resistivity is approximately 0.2 Omega -cm, regardless of the deep level location. In high-lifetime materials (10 ms), high injection level drives the optimum choice to high resistivity, 200 Omega -cm, regardless of the deep level location. For intermediate starting lifetimes (1000 mu s, 1 ms), location of the trap level can switch the optimum choice from low resistivity to high resistivity. It is shown that low resistivity is preferred for midgap deep levels, but high resistivity becomes desirable for shallow traps. >
IL-23 Promotes Maintenance but Not Commitment to the Th17 Lineage

IL-23 plays a critical role establishing inflammatory immunity and enhancing IL-17 production in vivo. However, an understanding of how it performs those functions has been elusive. In this report, using an IL-17-capture technique, we demonstrate that IL-23 maintains the IL-17-secreting phenotype of purified IL-17 + cells without affecting cell expansion or survival. IL-23 maintains the Th17 phenotype over multiple rounds of in vitro stimulation most efficiently in conjunction with IL-1β. However, in contrast to Th1 and Th2 cells, the Th17 phenotype is not stable and when long-term IL-23-stimulated Th17 cultures are exposed to Th1- or Th2-inducing cytokines, the Th17 genetic program is repressed and cells that previously secreted IL-17 assume the cytokine secreting profile of other Th subsets. Thus, while IL-23 can maintain the Th17 phenotype, it does not promote commitment to an IL-17-secreting lineage.
Tracking the evolution of alternatively spliced exons within the Dscam family

The Dscam gene in the fruit fly, Drosophila melanogaster, contains twenty-four exons, four of which are composed of tandem arrays that each undergo mutually exclusive alternative splicing (4, 6, 9 and 17), potentially generating 38,016 protein isoforms. This degree of transcript diversity has not been found in mammalian homologs of Dscam. We examined the molecular evolution of exons within this gene family to locate the point of divergence for this alternative splicing pattern. Using the fruit fly Dscam exons 4, 6, 9 and 17 as seed sequences, we iteratively searched sixteen genomes for homologs, and then performed phylogenetic analyses of the resulting sequences to examine their evolutionary history. We found homologs in the nematode, arthropod and vertebrate genomes, including homologs in several vertebrates where Dscam had not been previously annotated. Among these, only the arthropods contain homologs arranged in tandem arrays indicative of mutually exclusive splicing. We found no homologs to these exons within the Arabidopsis, yeast, tunicate or sea urchin genomes but homologs to several constitutive exons from fly Dscam were present within tunicate and sea urchin. Comparing the rate of turnover within the tandem arrays of the insect taxa (fruit fly, mosquito and honeybee), we found the variants within exons 4 and 17 are well conserved in number and spatial arrangement despite 248–283 million years of divergence. In contrast, the variants within exons 6 and 9 have undergone considerable turnover since these taxa diverged, as indicated by deeply branching taxon-specific lineages. Our results suggest that at least one Dscam exon array may be an ancient duplication that predates the divergence of deuterostomes from protostomes but that there is no evidence for the presence of arrays in the common ancestor of vertebrates. The different patterns of conservation and turnover among the Dscam exon arrays provide a striking example of how a gene can evolve in a modular fashion rather than as a single unit.
An 800-/spl mu/W 26-GHz CMOS tuned amplifier

A 26-GHz cascode tuned amplifier with a gain of 8.4dB, NF of /spl sim/5dB consuming 800/spl mu/W from a 1.0-V supply has been demonstrated in 130-nm CMOS technology. To increase the gain at given power consumption, the output resistances of cascode amplifier is increased by adding a series inductor at the gate of common-gate stage. The power consumption is more than 5/spl times/ lower than that of the previously reported CMOS amplifiers operating near 20 GHz.
Medication Management of Cardiac Allograft Vasculopathy After Heart Transplantation

Cardiac allograft vasculopathy (CAV) is a common complication following heart transplantation (HT), resulting in diminished graft survival. The preferred strategy for preventing CAV is optimal medical management; however, for patients who develop CAV, delaying disease progression through effective medication management is equally important. A review of the literature regarding medication management of CAV was conducted via a search of the MEDLINE database. Studies were included if they were published in English, conducted in humans ≥ 18 years of age or older, and used noninvestigational medications. Immunosuppressive medications such as the antiproliferative mycophenolate, the calcineurin inhibitor tacrolimus, and the proliferation signal inhibitors sirolimus and everolimus have been shown to prevent the development of CAV. Certain cardiovascular medications, such as HMG-CoA reductase inhibitors (statins), gemfibrozil, calcium channel blockers, and angiotensin-converting enzyme inhibitors, have also demonstrated efficacy in preventing this disease process. Prevention of CAV has also been observed with prophylaxis against cytomegalovirus infection and antioxidant medications. Despite being commonly used in HT patients, neither antiplatelet agents nor glycemic control have proved effective at preventing CAV. Only sirolimus has been shown to arrest the progress of existing CAV.
Reactions by differentially raised rhesus monkeys to noxious stimulation.

Adult monkeys reared in social-sensory isolation were compared with socially raised controls in 2 studies assessing aversive reactions to electric shock. In Experiment 1, the procedure involved competition between self-paced thirst and shock avoidance, presenting the monkey with a situation in which it had to absorb 2-sec of mouth-shock on a drinking tube to obtain water. When the monkey went through a response cycle by overcoming a given shock level, taking a variable number of unshocked drinks, and going 3 min without touching the drinking tube, the current was increased one step in a range from 0.1–2.5 mA. On measures of fluid intake and time per response cycle isolate monkeys did not differ from controls, suggesting that thirst motivation did not differ between groups. On shock trials isolates tolerated higher levels of shock than controls, even though they were initially more reactive to very low current levels. Isolates also showed more negative generalized effects of shock on nonshocked drinking tube contacts at a time when controls showed almost no generalized effects. In Experiment 2, neither isolates nor controls preferred to drink from a shocked over a nonshocked tube in a 2-choice free drinking situation, indicating that shock was a noxious stimulus for both groups. Thus, as in rats and dogs, stimulus deprivation during rearing produced anomalous reactions to noxious stimulation in monkeys.
Integrating the fourth dimension into orthodontic administration

Dear Dr Jerrold: When is the proper time to review and sign the informed consent form? In my practice, we use the form that came with our practice management software. This is then supplemented by an additional informed consent form that addresses specific concerns once we have reviewed the diagnostic records and arrived at a specific treatment plan. We do this at the separation visit, which is about a week before our appliance insertion visit. I have received legal advice to have the patients sign the informed consent form at the first visit before doing anything, including taking records. This seems a bit premature because the particulars of the case have not been determined. What is your opinion on this? Thanks. J. G. The short answer to our reader’s question is that an informed consent document should be signed at any time before the treatment plan is actually decided upon and certainly before any treatment is rendered. But what is treatment? Let’s step back a moment and look at this from the beginning. The patient’s mother, Ms Iwork Allday calls to make an initial screening appointment for her daughter, Needsome Retraction Allday. She is given an appointment, but, alas, it is during her hours of employment, so grandma, Ms Bornwith Straightteeth, brings our little model-to-be in for the examination. You perform an initial screening that consists of whatever you want it to consist of in terms of records and determine whatever it is you determine regarding starting now or waiting and, if applicable, the appliance du jour that you are recommending. Bornwith says that she will discuss what you told her with Iwork, and one of them will get back to you. Relative to informed consent, the first thing one must realize is that there is a difference between consent and informed consent. To put it into simple terms, consent is a threshold issue; before you can obtain a patient’s informed consent to render any form
Selective effect of liver disease on the activities of specific metabolizing enzymes: Investigation of cytochromes P450 2C19 and 2D6

Background and Objectives Drug metabolism is influenced by liver disease because of the central role that the liver plays in metabolic activities in the body. However, it is still unclear how activities of specific drug-metabolizing enzymes are influenced by the presence and severity of liver disease. As a consequence, alteration in metabolism of specific drugs cannot be easily predicted or appropriate dosage adjustment recommendations made. Methods The activities of cytochromes P450 (CYP) 2C19 and 2D6 were investigated in a group of patients with mild or moderate liver disease (n = 18) and a group of healthy control subjects (n = 10). The disposition of racemic mephenytoin for CYP2C19 and debrisoquin for CYP2D6 were characterized in plasma and urine samples collected over 192 hours. Results The elimination of S-mephenytoin was severely reduced among patients with liver disease, resulting in a 79% decrease in plasma clearance for all patients combined. This reduction was related to the severity of disease, patients with moderate disease being affected more severely than patients with mild disease. Similar differences were observed in the urinary excretion of 4′-hydroxymephenytoin metabolite. By contrast, there was no effect on the disposition of R-mephenytoin or debrisoquin. Conclusion These results show selectivity in the effect of liver disease on activities of specific metabolizing enzymes, CYP2C19 being more sensitive than CYP2D6. They suggest that recommendations for modification in drug dosage in the presence of liver disease should be based on knowledge of the particular enzyme involved in metabolism of the drug. The results emphasize the need for further studies of each specific drug-metabolizing enzyme in the presence of liver disease. Clinical Pharmacology & Therapeutics (1998) 64, 8–17; doi:
Acute effects of nimodipine on cerebral vasculature and brain metabolism in high grade subarachnoid hemorrhage patients

Nimodipine is the only medication shown to improve outcomes after aneurysmal subarachnoid hemorrhage (SAH). Preliminary theories regarding the mechanism by which it prevents vasospasm have been challenged. The acute physiologic and metabolic effects of oral Nimodipine have not been examined in patients with poor-grade SAH. This is an observational study performed in 16 poor-grade SAH patients undergoing multimodality monitoring who received oral Nimodipine as part of routine clinical care. A total of 663 doses of Nimodipine were observed. Changes in physiologic measurements including MAP, CPP, ICP, PbtO2, and CBF were examined. Administration of oral Nimodipine was associated with a 1.33 mmHg decrease in MAP (P < 0.001) and a 1.22 mmHg decrease in CPP (P < 0.001). When administration of Nimodipine was associated with MAP decreases, PbtO2 (1.03 mmHg; P < 0.001) and CBF (0.39 ml/100 g/min; P = 0.002) also decreased. Despite CPP targeted therapy with vasopressor medication, oral Nimodipine was associated with a decrease in MAP and CPP. When Nimodipine administration was associated with a decrease in MAP, there were concomitant drops in PbtO2 and CBF. These findings suggest that MAP support after oral Nimodipine may be important to maintain adequate CBF in patients with poor-grade subarachnoid hemorrhage.
Feeding mice aged and fresh blackberries powder supplements result in shifts in the gastrointestinal microflora

Abstract Blackberries contain anthocyanins and phenolic acids derived from anthocyanin fragments that have an important role in the small intestine for retaining gut health. It has been hypothesized that supplementing diets with blackberries may improve gut health through a prebiotic mechanism. Unfortunately identification of gut bacteria is difficult since only 20% of bacterial species can be cultured using current techniques. Therefore, a non-culture based technique was utilized to examine shifts in gut bacteria of mice fed one of five diet treatments: (1) control, (2) aged blackberries supplemented at 5% (w/w), (3) aged blackberries supplemented at 10% (w/w), (4) fresh blackberries supplemented at 5% (w/w), and (5) fresh blackberries supplemented at 10% (w/w). Mice feces were initially collected before supplementing blackberries as a control (0 week) and were collected every 2 weeks for up to 10 weeks. Polymerase chain reaction-based denaturing gradient gel electrophoresis (PCR-based DGGE) was performed and further identification of bacteria was conducted by excising and sequencing target bands. Banding patterns were more consistent over time in those groups that had a diet supplemented with 10% aged or fresh blackberries compared to the 2 groups fed a diet supplemented with 5% of fresh or aged blackberries. From the sequencing data, Lactobacillus johnsonii was present in all groups after 2 weeks of sampling. The Aerococcus spp. and Actinomycetes were increased in blackberries treatments as well as Enterobacter spp., Klebsiella pneumonia and Erwinia spp. were present in aged blackberry treatment. These data indicate that supplementing a diet with aged or fresh blackberries causes shifts in the gastrointestinal microflora.
Analysis of Convectively Coupled Kelvin Waves in the Indian Ocean MJO

Abstract The active convective phase of the Madden–Julian oscillation (hereafter active MJO) comprises enhanced moist deep convection on its own temporal and spatial scales as well as increased variance in convection associated with higher-frequency modes. Synoptic-scale cloud superclusters apparently associated with convectively coupled Kelvin waves occur within the active convective envelopes of most MJO events. These convectively coupled Kelvin waves also occur during the suppressed convective phase of the MJO (hereafter suppressed MJO). This observational study presents an analysis of outgoing longwave radiation and reanalysis data to determine how these waves behave differently as they propagate through the active and suppressed MJO. Time indices of the MJO and Kelvin waves are derived for over the equatorial Indian Ocean. Dates of local extrema in these indices are used to composite data to discern how the waves and associated circulations behave on average; then, further composites are made based o...
Cytokine profiles in localized scleroderma and relationship to clinical features

Localized scleroderma (LS) is a disfiguring autoimmune disease of the skin and underlying tissue that mainly affects the pediatric population. Inflammation of the tissue leads to fibrosis and atrophy, causing physical and psychological disability that can continue throughout childhood into adulthood. Available therapies for LS have had variable effects and are associated with morbidity themselves. A better understanding of the pathophysiology of LS, especially during the active inflammatory phase, would lead to more directed and efficacious therapies. As in systemic sclerosis (SSc), the other form of scleroderma, T-helper (Th) cells and their associated cytokines have been suggested to contribute significantly to the pathophysiology of LS supported by the presence of cytokines from these lineages in the sera and tissue of LS patients. It is postulated that the imbalance between Th1/Th2/Th17 cell subsets drives inflammation in the early stages of disease (Th1 and Th17 predominant) and fibrosis in the later stages of scleroderma (Th2 predominant). We review the available experimental data regarding cytokines in LS and compare them to available clinical disease severity and activity features. This provides the platform to launch further investigations into the role of select cytokines in the pathogenesis of LS and to provide directed therapeutic options in the future.
Observation of the Beam-Beam Limit in CESR

CESR has produced e+ e- collisions for high energy physics in the very productive T region (4.7 to 5.7 GeV per beam) since the fall of 1979. The peak luminosity recorded during physics data taking over that period is shown in Fig. 1. The dramatic increase in the luminosity has resulted from the reduction of sy* from 11 cm to 3 cm, an increase in ?x *, and increases in the vertical aperture. Furthermore, observations of the beam-beam interaction show that the luminosity increases as the square of the beam current at low currents and linearly with current at high currents. These observations are consistent with a vertical beam size which is constant at low currents and increases linearly at high currents. A linearly increasing vertical beam size implies a constant vertical tune shift. The luminosity and the beam lifetime are limited by nongaussian tails which reach the physical aperture of CESR.
Overcoming JVM HotSwap constraints via binary rewriting

Java HotSpot VM provides a facility for replacing classes at runtime called HotSwap. One design property of HotSwap is that the signature of a replaced class must remain the same between different versions, which significantly constrains the programmer modifying a class to be replaced. Specifically, the programmer is precluded from adding new methods, constructors, or fields, or even changing the signatures of existing methods or fields. This paper presents a novel approach that overcomes these constraints of HotSwap by using binary refactoring, a technique that rewrites the binary representation of a program without affecting its functionality. A series of micro and macro benchmarks we conducted demonstrate that the approach is extensible and efficient. In particular, the new binary refactoring technique, which enables the approach, produces highly-efficient refactored application versions, outperforming a widely-used prior technique by as much as an order of magnitude. These initial results indicate that by rewriting the bytecode of a swapped program, one can effectively overcome constraints of HotSwap with minimal performance overhead.
Isothermal titration calorimetry of RNA.

Abstract Isothermal titration calorimetry (ITC) is a fast and robust method to study the physical basis of molecular interactions. A single well-designed experiment can provide complete thermodynamic characterization of a binding reaction, including Ka, ΔG, ΔH, ΔS and reaction stoichiometry (n). Repeating the experiment at different temperatures allows determination of the heat capacity change (ΔCP) of the interaction. Modern calorimeters are sensitive enough to probe even weak biological interactions making ITC a very popular method among biochemists. Although ITC has been applied to protein studies for many years, it is becoming widely applicable in RNA biochemistry as well, especially in studies which involve RNA folding and RNA interactions with small molecules, proteins and with other RNAs. This review focuses on best practices for planning, designing and executing effective ITC experiments when one or more of the reactants is an RNA.
In-vivo spinal cord deformation in flexion

Traumatic mechanical loading of the head-neck complex results cervical spinal cord injury when the distortion of the cord is sufficient to produce functional or structural failure of the cord's neural and/or vascular components. Characterizing cervical spinal cord deformation during physiological loading conditions is an important step to defining a comprehensive injury threshold associated with acute spinal cord injury. In this study, in vivo quasi- static deformation of the cervical spinal cord during flexion of the neck in human volunteers was measured using magnetic resonance (MR) imaging of motion with spatial modulation of magnetization (SPAMM). A custom-designed device was built to guide the motion of the neck and enhance more reproducibility. the SPAMM pulse sequence labeled the tissue with a series of parallel tagging lines. A single- shot gradient-recalled-echo sequence was used to acquire the mid-sagittal image of the cervical spine. A comparison of the tagged line pattern in each MR reference and deformed image pair revealed the distortion of the spinal cord. The results showed the cervical spinal cord elongates during head flexion. The elongation experienced by the spinal cord varies linearly with head flexion, with the posterior surface of the cord stretching more than the anterior surface. The maximal elongation of the cord is about 12 percent of its original length.
Effects of tedisamil (KC-8857) on cardiac electrophysiology and ventricular fibrillation in the rabbit isolated heart

1. The direct cardiac electrophysiological and antifibrillatory actions of tedisamil (KC-8857) were studied in rabbit isolated hearts. 2. Tedisamil (1, 3, and 10 microM), prolonged the ventricular effective refractory period (VRP) from 120 +/- 18 ms (baseline) to 155 +/- 19, 171 +/- 20, and 205 +/- 14 ms, respectively. Three groups of isolated hearts (n = 6 each) were used to test the antifibrillatory action of tedisamil. Hearts were perfused with 1.25 microM pinacidil, a KATP channel activator. Hearts were subjected to hypoxia for 12 min followed by 40 min of reoxygenation. Ventricular fibrillation (VF) developed during hypoxia and reoxygenation in both the control and 1 microM tedisamil-treated groups (5/6 and 4/6, respectively). Tedisamil (3 microM) reduced the incidence of VF (0/6, P = 0.007 vs. control). 3. In a separate group of hearts, VF was initiated by electrical stimulation. The administration of 0.3 ml of 10 mM tedisamil, via the aortic cannula, terminated VF in all hearts, converting them to normal sinus rhythm. 4. Tedisamil (3 microM) reversed pinacidil-induced negative inotropic effects in rabbit isolated atrial muscle which were equilibrated under normoxia, as well as in atrial muscle subjected to hypoxia and reoxygenation. 5. The results demonstrate a direct antifibrillatory action of tedisamil in vitro. The mechanism responsible for the observed effects may involve modulation by tedisamil of the cardiac ATP-regulated potassium channel, in addition to its antagonism of IK and Ito.
Efficient utilization of visible light in the photoreduction of chloroaromatic compounds

Abstract Photocatalytic reduction of chloroaromatics to the corresponding aromatic compounds has been accomplished using visible dyes in the presence of amines. An electron transfer mechanism is implicated by the experimental results, with the formation of an aryl chloride radical anion being the key step leading to dechlorination.
Prediction during language comprehension: Benefits, costs, and ERP components

Because context has a robust influence on the processing of subsequent words, the idea that readers and listeners predict upcoming words has attracted research attention, but prediction has fallen in and out of favor as a likely factor in normal comprehension. We note that the common sense of this word includes both benefits for confirmed predictions and costs for disconfirmed predictions. The N400 component of the event-related potential (ERP) reliably indexes the benefits of semantic context. Evidence that the N400 is sensitive to the other half of prediction--a cost for failure--is largely absent from the literature. This raises the possibility that "prediction" is not a good description of what comprehenders do. However, it need not be the case that the benefits and costs of prediction are evident in a single ERP component. Research outside of language processing indicates that late positive components of the ERP are very sensitive to disconfirmed predictions. We review late positive components elicited by words that are potentially more or less predictable from preceding sentence context. This survey suggests that late positive responses to unexpected words are fairly common, but that these consist of two distinct components with different scalp topographies, one associated with semantically incongruent words and one associated with congruent words. We conclude with a discussion of the possible cognitive correlates of these distinct late positivities and their relationships with more thoroughly characterized ERP components, namely the P300, P600 response to syntactic errors, and the "old/new effect" in studies of recognition memory.
Postoperative bowel function, symptoms, and habits in women after vaginal reconstructive surgery

The objective was to characterize postoperative bowel symptoms in women undergoing vaginal prolapse reconstructive surgery randomized to preoperative bowel preparation vs a regular diet. Subjects (N = 121) completed two bowel diaries: a 7-day bowel diary immediately before surgery and a 14-day diary postoperatively. Self-reported bowel diary data and symptoms included the time to first bowel movement (BM), daily number of BMs, Bristol Stool Form Scale score, pain, and urgency associated with BM, episodes of fecal incontinence, and use of laxatives. Antiemetic use was abstracted from medical records. Outcomes of groups were compared using Chi-squared/Fisher’s exact test or Student’s t test as appropriate. Mean time to first postoperative BM was similar in the bowel preparation (n = 60) and control groups (n = 61), 81.2 ± 28.9 vs 78.6 ± 28.2 h, p = 0.85. With the first BM, there were no significant differences between bowel preparation and control groups regarding pain (17.2 vs 27.9 %, p = 0.17), fecal urgency with defecation (56.9 vs 52.5 %, p = 0.63), fecal incontinence (14.0 vs 15.0 %, p = 0.88) and >1 use of laxatives (93.3 vs 96.7 % p = 0.44) respectively. Antiemetic use was similar in both groups (48.3 vs 55.7 % respectively, p = 0.42). There were no differences in the return of bowel function and other bowel symptoms postoperatively between the randomized groups. Lack of bowel preparation does not have an impact on the risk of painful defecation postoperatively. This information may be used to inform patients regarding expectations for bowel function after vaginal reconstructive surgery.
Effect of Ni+-ION bombardment on nickel and binary nickel alloys

Abstract Pure nickel and four binary nickel alloys have been subjected to high energy Ni ion bombardment at 675, 625 and 525°C. After irradiation, each specimen was studied by transmission electron microscopy. The pure nickel control was found to swell appreciably (1 to 5%) and the Ni-Al and the Ni-Ti samples were found to swell at all temperatures, but to a lesser degree (0.01 to 0.35%). The Ni-Mo contained a significant density of voids only at 525° C, while swelling was suppressed at all temperatures in the Ni-Si alloy. The dislocation structure progressed from loops to tangles as temperature increased in all materials except the Ni-Ti, in which there was an absence of loops at all temperatures. Dislocation densities decreased as temperature increased in all samples. These results do not correlate well with the relative behavior of the same alloys observed after neutron irradiation at 455°C. The differences between these two sets of data appear to be caused by different mechanisms controlling void nucleation in ion and neutron irradiation of these alloys.
Radionuclides in marine macroalgae from Amchitka and Kiska Islands in the Aleutians: establishing a baseline for future biomonitoring.

Abstract Levels of radionuclides in seven species of marine brown algae and Ulva were determined to establish a baseline for the Northern Pacific Ocean/Bering Sea (Aleutian Islands). There were differences in levels among algal species and locations (Amchitka Island vs Kiska Island). No values were above the minimum detectable activity (MDA) level for 137 Cs, 129 I, 60 Co, 152 Eu, 90 Sr, and 99 Tc. There were interspecific differences in some radionuclides: Ulva lactuca (= Ulva fenestrata ) had the highest levels of 241 Am, Alaria fistulosa had the highest levels of 239,240 Pu, and Fucus distichus (= Fucus gardneri ) had the highest levels of 234 U, 235 U, and 238 U. However, levels of all radionuclides were generally low and near the MDA for all isotopes. Although Amchitka Island had higher levels of 239,240 Pu than Kiska, the differences were very small and not significant biologically. The data indicate that algae can be useful bioindicators of actinides because they accumulate them at very low environmental levels, allowing them to provide early warning of any potential seepage of radionuclides into the marine environment. Further, the data indicate that some species (the intertidal Fucus ) are better accumulators than others, and these should be used as bioindicators in future monitoring schemes.
Local atomicity properties: modular concurrency control for abstract data types

Atomic actions (or transactions) are useful for coping with concurrency and failures. One way of ensuring atomicity of actions is to implement applications in terms of atomic data types: abstract data types whose objects ensure serializability and recoverability of actions using them. Many atomic types can be implemented to provide high levels of concurrency by taking advantage of algebraic properties of the type's operations, for example, that certain operations commute. In this paper we analyze the level of concurrency permitted by an atomic type. We introduce several local constraints on individual objects that suffice to ensure global atomicity of actions; we call these constraints local atomicity properties. We present three local atomicity properties, each of which is optimal: no strictly weaker local constraint on objects suffices to ensure global atomicity for actions. Thus, the local atomicity properties define precise limits on the amount of concurrency that can be permitted by an atomic type.
Ionic selectivity of the paracellular shunt path across rabbit corneal endothelium.

We have measured the dilution and biionic potentials across the isolated rabbit corneal endothelium in order to learn about the ionic selectivity of its intercellular junctions. Single-salt dilution potentials have been measured as a function of [NaCl] or [NaHCO3] gradients across the tissue. Biionic potentials were similarly measured by replacing Na+ with K+ on either side of the tissue. The potentials thus measured were fit to the constant field equation and to an approximation of it to obtain the ionic permeabilities for K+, HCO 3 − and Cl− relative to Na+. The permeability sequence obtained wasPK>PNa>PHCO3≅PCl. Potentials were also measured after imposing an osmotic gradient across the preparation using sucrose. The results obtained with all these methods are consistent and suggest that this tissue is slightly more permeant to cations than anions, but that the selectivity of the intercellular junction is relatively low. From these experiments, a 30mm gradient of salt across the endothelial layer would be needed in order to explain the observed spontaneous potential difference (about 1 mV, aqueous negative) across that layer if the potential was due to the selectivity of the intercellular junctions. Such a value for the gradient is much larger than theoretical estimates of it; therefore, we favor electrogenic transport of HCO 3 − as a better explanation for the origin of the spontaneous potential difference.
Organogenesis in tissue culture of Solanum melongena cv. Florida Market

Abstract Cell suspension cultures were initiated from pith callus of eggplant, Solanum melongena cv. Florida Market on Murashige and Skoog (MS) medium supplemented with 13.5 μM 2,4-dichlorophenoxyacetic acid (2,4-D). The effects of mineral salts (MgSO4, KNO3, CaCl2), sucrose and 2,4-D were studied on aggregate formation in suspension cultures. Aggregates from a cell suspension when cultured on an MS agar medium supplemented with various concentrations and combinations of indole-3-acetic acid (IAA) and γ,γ-isopentenyl adenine (2iP) differentiated into green nodules, but they failed to develop into organized shoots on the same medium. Upon transfer of these green nodules to MS medium supplemented with 0.1 μM ascorbic acid (autoclaved with the medium) alone or in combination with 49 μM 2iP, developed further into organized leafy shoots. This suggests that some degradation product of ascorbic acid might be responsible for inducing leafy shoots. Based on leaf morphology and chromosome analysis, regenerated plants were identified as tetraploids.
Beyond the robust design: Accounting for changing, uncertain states and sparse, biased detection in a multistate mark-recapture model

We develop a multistate mark-recapture likelihood function to estimate reproductive rate when state classification uncertainty is present (a lone female may or may not have offspring), females may transition between states (give birth) during many of the within-season sampling periods, and female detection is uneven because it is a function of an unknown admixture of state-dependency and observer effort, which are linked via location. We show how to address these multiple problems, even with sparse data, by deriving explicit functions for state transitions and state detection, and by combining a modicum of auxiliary information indicative of a female's reproductive state with a mild assumption about the relationship between detection rate and reproductive rate. We incorporate this likelihood function into a Bayesian framework to estimate reproductive rate for the threatened eastern stock of Steller sea lions (Eumetopias jubatus) in Southeast Alaska, a population for which reproductive rate has never been estimated. Our methods relax previous assumptions of multistate mark-recapture models and facilitate inference from ecological systems where sampling effort is highly constrained.
An evaluation of three spatial differencing schemes for the discrete ordinates method in participating media

Three popular spatial differencing schemes for the discrete ordinates method are examined for two-dimensional Cartesian coordinates system. These are a positive, the step, and the diamond schemes. Contrary to the common belief that negative intensities will not occur when fine spatial discretization is used with the diamond scheme, under certain conditions, the diamond scheme will produce negative intensities irrespective of the number of control volums employed. The positive scheme can produce physically unrealistic trends. The diamond and positive schemes are also capable of producing physically unrealistic overshoots. In absorbing-emitting or absorbing-emitting-scattering media, grid refinement can result in negative intensities when the diamond or positive scheme is used.
Spotted cotton oligonucleotide microarrays for gene expression analysis

Microarrays offer a powerful tool for diverse applications plant biology and crop improvement. Recently, two comprehensive assemblies of cotton ESTs were constructed based on three Gossypium species. Using these assemblies as templates, we describe the design and creation and of a publicly available oligonucleotide array for cotton, useful for all four of the cultivated species. Synthetic oligonucleotide probes were generated from exemplar sequences of a global assembly of 211,397 cotton ESTs derived from >50 different cDNA libraries representing many different tissue types and tissue treatments. A total of 22,787 oligonucleotide probes are included on the arrays, optimized to target the diversity of the transcriptome and previously studied cotton genes, transcription factors, and genes with homology to Arabidopsis. A small portion of the oligonucleotides target unidentified protein coding sequences, thereby providing an element of gene discovery. Because many oligonucleotides were based on ESTs from fiber-specific cDNA libraries, the microarray has direct application for analysis of the fiber transcriptome. To illustrate the utility of the microarray, we hybridized labeled bud and leaf cDNAs from G. hirsutum and demonstrate technical consistency of results. The cotton oligonucleotide microarray provides a reproducible platform for transcription profiling in cotton, and is made publicly available through http://cottonevolution.info .
Particle dynamics and aggregation of crystals in a magma chamber with application to Kilauea Iki olivines

Abstract Crystals settling in relative proximity to each other will settle faster than their respective Stokes' velocities ( U S ) due to their mutual interactions. Pairs of equant spheres (within 100 diameters of each other) are accelerated to 1.55 U S . Modification of Han and Lawler's [Han, M., Lawler, D.F., 1991. Interactions of two settling spheres: settling rates and collision efficiency. Journal of Hydraulic Engineering 117 (10) 1269–1289] equations to include inertia shows that the velocities of a pair of spheres differ and change during descent, allowing them to come into contact. In quiescent settling experiments with olivine-shaped clay prisms, the pairs of prisms usually settled faster than their U S . The clay prisms aggregated 80% of the time, with the pairs of prisms rotating and tumbling as they fall, coming into and out of contact. Size variations in Kilauea Iki olivines control aggregation during quiescent settling. The settling velocities of individual crystals are variable, increasing when they are incorporated into aggregates. A suspension of olivine crystals (more than 0.01 vol.%) in a magma will settle slower than the average Stokes' velocities, except when a buoyant phase is present. Addition of a buoyant phase, such as CO 2 bubbles, can increase the settling velocity of the olivines when the total concentration (olivine plus bubbles) ( e ) is e >35%.
Channel structures of gramicidin: characterization of succinyl derivatives

Succinyl derivatives of gramicidin were tested for their ability to form channels in planar artificial lipid bilayers. Both N-succinyldeformylgramicidin methyl ester and charged O-succinylgramicidin formed channels, but the channels had markedly different sizes and lifetimes. This implies that gramicidin forms channels by end-to-end association. However, the doubly charged N,O-bissuccinyldeformylgramicidin was inactive, which suggests that only end-to-end association of gramicidin may result in channel formation.