cssi/SciSciGPT-SciSciNet huggingface dataset:
Emerging pharmacotherapeutic strategies for cholangiocarcinoma

Introduction: Although of limited clinical benefit, chemotherapy represents the cornerstone of management for patients with inoperable cholangiocarcinoma. The literature on chemotherapy in advanced cholangiocarcinoma is difficult to interpret because of the heterogeneity of cholangiocarcinoma, the use of various chemotherapeutic agents in different combinations and dosing regimens, and the small size of existing patient cohorts. Areas covered: The authors discuss the major advances in the therapy of cholangiocarcinoma over the past decade. The audience will become familiarized with the contemporary medical management of cholangiocarcinoma and potentially useful agents/combinations for the therapy of this entity in the future. Expert opinion: In recent years, gemcitabine-based chemotherapy has improved overall survival in advanced cholangiocarcinoma. Although gemcitabine–cisplatin combination represents the largely accepted standard for biliary cancers at present, very few studies so far have looked at the...
Pharmocokinetic and pharmacodynamic evaluation of intravenous morphine in dogs

Morphine is considered the prototypical opiate analgesic. Despite the common use of morphine in dogs, ideal dosing strategies have not been formulated due to the difficulty in assessing its analgesic effects. The purpose of this study was to: 1) evaluate a noninvasive mechanical threshold device (von Frey device) to measure antinociceptive responses (pharmacodynamics) of opiates in dogs and 2) evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of intravenous (IV) morphine in dogs. Six healthy Beagle dogs were used. The von Frey threshold (vFT) response was evaluated hourly for 8 hours in each dog to examine the effect of repeated testing (controls). PK and PD (vFT) measurements were then made following a 1 mg kg–1 IV bolus of morphine sulfate. A two way blinded crossover consisted of an 8 hour IV constant rate infusion of saline or morphine with hourly PD measurements. The individual CRI was based on individual PK data and adjusted every 2 hours to attain targeted plasma concentrations of morphine of 10, 20, 30, and 40 ng mL–1. Blood samples were taken hourly in all phases, except the controls. No significant (p > 0.05) intraindividual changes in vFT occurred in the controls over 8 hours. The morphine bolus produced increased vFT at 1, 2, 3, and 4 hours post injection (p 30 ng mL–1, when compared to saline controls (p < 0.05). Targeted plasma concentrations were inconsistent at higher infusion rates, suggesting the PK of morphine may change during CRI. The actual mean ± SD CRI plasma concentrations (ng ml–1) were 10.8 ± 3.0, 22.7 ± 7.4, 32.4 ± 13.9, 35.7 ± 16.9. Morphine dosing protocols should be re-evaluated, as sufficient analgesia may not be obtained from published dosages. Intravenous boluses may be more predictable than CRI.
Solid-phase extraction of herbicides from well water for determination by gas chromatography-mass spectrometry

Abstract A simple, rapid method for isolating herbicides from well water was developed using disposable octadecyl (C18) solid-phase extraction columns. Deuterium-labeled internal standards were used to compensate for any losses that may have occurred during sample preparation owing to matrix effects. Detection by capillary gas chromatography-mass spectrometry in the selected ion monitoring mode minimized the frequency of false-positive results. The accuracy of the method was ± 5% at concentrations > 0.20μg l−1 for four of the five herbicides studied.
Reactions of aminomalononitrile with electrophiles.

Aminomalononitrile (HCN trimer) reacts with electrophiles such as aldehydes and acrylonitrile under very mild conditions of temperature and pH to produce intermediates which, after acid hydrolysis, yield amino acids. The following amino acids have been identified and quantitated: glycine, D, L-erythro- and D, L-threo-s - hydroxyaspartic acids, D, L glutamic acid, and D, L-threonine and allo-threonine. The mechanism of their formation and the possible significance of these reactions in prebiotic syntheses are discussed.
Rate Coefficient Measurements of the Reaction CH3+O2+CH3O+O

Rate coefficients for the reaction CH3 + O2 = CH3O + O were measured behind reflected shock waves in a series of lean CH4-O2-Ar mixtures using hydroxyl and methyl radical diagnostics. The rate coefficients are well represented by an Arrhenius expression given as k = (1.60(sup +0.67, sub -0.47 ) x 10(exp 13) e(-15813 +/- 587 K/T)/cubic cm.mol.s. This expression, which is valid in the temperature range 1575-1822 K, supports the downward trend in the rate coefficients that has been reported in recent determinations. All measurements to date, including the present study, have been to some extent affected by secondary reactions. The complications due to secondary reactions, choice of thermochemical data, and shock-boundary layer interactions that affect the determination of the rate coefficients are examined.
In vitro temperature change at the dentin/pulpal interface by using conventional visible light versus argon laser.

Background and Objective The argon laser has been promoted as a competing technology to multi-wavelength visible light as a curing source for dental restorative resins. However, the comparative thermal risk to the pulp between these two sources of light energy requires determination. The objective of this study is to compare the temperature induced at the dentin-pulpal interface between the argon laser and visible light curing unit at a variety of exposure regimens and conditions. Study Design/Materials and Methods In vitro temperatures were measured and recorded at the dentin-pulpal interface upon external light exposure. Independent variables included the dentin thickness, duration and waveform of exposure, and presence of composite resin. Results In most instances, the argon laser resulted in less temperature rise on the pulpal-dentin interface. Conclusion The argon laser should not pose a serious thermal risk to the pulp if used at recommended energies. Lasers Surg. Med. 26:386–397, 2000 © 2000 Wiley-Liss, Inc.
2D elastic analysis of the sandwich panel buckling problem: benchmark solutions and accurate finite element formulations

This paper is concerned with the elastic stability of a sandwich beam panel using classical elasticity. An exact solution for the buckling problem of a sandwich panel (wide beam) in uniaxial compression is presented. Various formulations that correspond to the use of different pairs of energetically conjugate stress and strain measures for the infinitesimal elastic stability of the sandwich panel are discussed. Results from the present two-dimensional analyses to predict the global and local buckling of a sandwich panel are compared with previous theoretical and experimental results. A new finite element formulation for the bifurcation buckling problem is also introduced. In this new formulation, terms that influence the buckling load, which have been omitted in popular commercial codes are pointed out and their significance in influencing the buckling load is identified. The formulation and results presented here can be used as a benchmark solution to establish the accuracy of numerical methods for computing the buckling behavior of thick, orthotropic solids.
Pilot study of adriamycin and amsacrine (m-AMSA) in patients with advanced breast cancer.

Twelve patients with recurrent and metastatic breast cancer were treated with a combination of adriamycin and amsacrine (m-AMSA) to evaluate its efficacy and toxicity. Adriamycin was given at 40 mg/m2 i.v. and m-AMSA at 50 mg/m2 i.v. every 3 weeks. No response was observed. One patient received an escalated m-AMSA dose at 70 mg/m2 and the same dose of adriamycin. She died of treatment-related leukopenia and infection. We conclude that the combination of adriamycin and amsacrine at the dose and schedule used in our trial has little antitumor effect in the treatment of advanced breast cancer.
Extension of high‐order compact schemes to time‐dependent problems

In this article, we present an extension of our previous approaches for steady-state higher-order compact (HOC) difference methods to time-dependent problems. The formulation also provides a framework for similar treatment of other HOC spatial schemes. A stability analysis is provided for transient convection-diffusion in 1D and transient diffusion in 2D. Supporting numerical experiments are included to illustrate stability and accuracy as well as oscillatory and dissipative behavior. © 2001 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 17: 657–672, 2001
Quality of service provision in combined input and crosspoint queued switches without output queueing match

Packet switches play one of the most critical roles in supporting quality of service (QoS) in computer communication networks. Although the output queued (OQ) switch architecture can achieve optimal QoS performance, it is not a practical architecture for high-speed switching due to the switching fabric speedup, which requires complex implementation. Combined input and crosspoint queued (CICQ) switches employ the crossbar-based switching fabric structure and apply buffers at both ingress port modules and crosspoints inside the switching fabric. This switch architecture is promising to achieve high performance without complex implementation. Current available approaches for QoS provision in CICQ switches are based on the output queueing match technique. Although such approaches can provide bandwidth and delay guarantees, they still require switching fabric speedup, which may significantly increase the implementation complexity of high-speed CICQ switches. In this paper, we compare the QoS performance that can be achieved in CICQ switches with the QoS performance guaranteed by OQ switches. Based on this comparison, we investigate the possibility of achieving equivalent QoS guarantees in a CICQ switch as in an OQ switch without output queueing match, thus with no switching fabric speedup. Our analysis shows that if sufficient crosspoint buffer space is allocated, a CICQ switch employing a typical scheduling algorithm, such as weighted fairing queueing (WFQ), can provide an identical bandwidth guarantee as the OQ switches without any switching fabric speedup, and can achieve equivalent delay performance as the OQ switch by slightly increasing bandwidth allocation.
Anomalous Electrical Resistivity and Magnetoresistance Due to an s − d Interaction in Cu-Mn Alloys

The effect of the $s\ensuremath{-}d$ exchange interaction between the conduction electrons and the Mn ions on the electrical behavior of Cu-Mn alloys is investigated from the molecular-field point of view. The magnitude of the anomalous resistivity calculated with the value of the exchange integral for a free ${\mathrm{Mn}}^{+}$ ion agrees with the experimental value within a factor of three. Also the temperature dependence of the resistivity obtained by the molecular-field approximation for the antiferromagnetic spin ordering is shown to be quite similar to the behavior exhibited by the alloys with more than one atomic percent Mn. For samples with lower concentration of Mn ions, however, the theoretical result shows only a monotonic decrease of the resistance below the N\'eel temperature. It shows neither the resistance minimum nor maximum which has been found experimentally for the very dilute alloys. The anomalous magnetoresistance calculated on the same basis is approximately proportional to the square of the magnetization and its magnitude is in good agreement with the experimental results, especially above the N\'eel temperature. The magnetoresistance of ferromagnetic metals is also discussed.
Results of laparoscopic antireflux surgery for dysphagia and gastroesophageal reflux disease

Abstract Background: Little attention has been paid to nonobstructive dysphagia (dysphagia in the absence of an esophageal stricture) in patients with gastroesophageal reflux disease (GERD). The objectives of this study were to assess (a) the incidence of nonobstructive dysphagia in patients with GERD; and (b) the effects of laparoscopic fundoplication on nonobstructive dysphagia. Methods: Esophageal manometry and pH monitoring identified 666 patients with GERD. Two hundred and eight patients (31%) without esophageal strictures complained of dysphagia in addition to heartburn and regurgitation. Forty-nine (24%) of these patients underwent laparoscopic fundoplication. Esophageal function tests were repeated postoperatively in 12 patients (25%). Main outcome measures were effects of laparoscopic fundoplication on symptoms and esophageal motor function. Results: Dysphagia resolved postoperatively in 44 patients (90%), and improved in 2 patients (4%). Postoperative esophageal manometry showed a significant increase in the length and pressure of the lower esophageal sphincter, without changes in its ability to relax in response to swallowing. Conclusions: About one third of GERD patients without strictures experienced dysphagia; and dysphagia resolved in about 90% of such patients following a laparoscopic fundoplication.
Dominance solvable games and trees

Abstract We study social choice functions represented by Moulin's dominance solvable games. We first show that dominance solvability of games is independent of the order in which dominated strategies are deleted. This implies that the perfect equilibrium of a game with perfect information generally coincides with its solution according to dominance solvability. Then we show that a large class of d-solvable games yields the same social choice functions as those represented by games of perfect information. We show that for three alternatives and all n relatively prime to 6 there exists a method of social choice fractional elimination, which can be represented by a kingmaker tree. This covers some cases not previously covered by Moulin. We also find numerous examples.
Passive immunization protects guinea pigs from lethal Toxoplasma infection.

The cellular and humoral interactions that contribute to protective immunity in toxoplasmosis were studied by adoptive transfer of selective cell populations or immune serum and its fractions into normal syngeneic strain 2 guinea pigs. The results of this study with the RH strain of Toxoplasma gondii confirm and extend the findings of previous studies by showing that the passive transfer of parasite-sensitized T cells or of immune serum from previously infected donors protected recipient guinea pigs against lethal toxoplasmosis. An additional key finding was that similar levels of complete protection against lethal infection occurred in guinea pigs receiving partially purified anti-Toxoplasma immunoglobulins or immune cells that had been enriched for B cells prior to transfer. Cells residing in the spleen, lymph nodes and peritoneal cavity, but not the thymus, were equally effective in conferring immunity to challenged recipients. In addition, cell titration experiments revealed that guinea pigs could survive T. gondii infection by infusing them with as little as 2 × 107 sensitized T cells or B cells. Unlike protection mediated by T cells, protection against lethal disease occurring in the B cell recipients was associated with the formation of Toxoplasma antibodies. These findings illustrate the major role of both humoral and cell-mediated immunity in affording protection against toxoplasmosis based on a guinea pig model of the human disease.
Determination of Spontaneous Emission Quantum Efficiency in InGaAs/GaAs Quantum Well Structures

The injection and temperature dependence of the spontaneous emission quantum efficiency of molecular beam epitaxy grown InGaAs/GaAs quantum wells is determined using excitation dependent photoluminescence (PL) measurements. The PL measurements were performed at temperatures from 50 to 300 K using a HeNe pump laser with powers ranging from 0.6 to 35 mW. The quantum efficiency is inferred from the power law predicted by the rate equations that links pump power and integrated PL signal. The peak spontaneous emission quantum efficiency of molecular beam epitaxy (MBE) grown InGaAs/GaAs triple quantum wells is determined to be 0.941 at 300K with an overall best value of 0.992 at 100 K.
Can a beverage cart help improve hydration

The purpose of this study was to determine the effectiveness of a hydration program to improve hydration and prevent conditions associated with dehydration (delirium, urinary tract infections, respiratory infections, falls, skin breakdown, and constipation). Data showed a significant increase in fluid in each body compartment, significant decrease in the number of laxatives, increase in the number of bowel movements, decline in the number of falls, and decrease in cost during the hydration period.
Chloracne. Clinical manifestations and etiology.

Chloracne is a rare but important acneiform eruption often associated with ingestion of chlorinated phenolic agents. Clinically, it can be distinguished from acne vulgaris by its distribution and appearance and by a detailed history. It is difficult, if not impossible, to treat adequately, making good hygiene, safe manufacturing processes, and elimination of atmospheric contamination imperative.
Task-dependent and task-independent neurovascular responses to syntactic processing

The neural basis for syntactic processing was studied using event-related fMRI to determine the locations of BOLD signal increases in the contrast of syntactically complex sentences with center-embedded, object-extracted relative clauses and syntactically simple sentences with right-branching, subject-extracted relative clauses in a group of 15 participants in three tasks. In a sentence verification task, participants saw a target sentence in one of these two syntactic forms, followed by a probe in a simple active form, and determined whether the probe expressed a proposition in the target. In a plausibility judgment task, participants determined whether a sentence in one of these two syntactic forms was plausible or implausible. Finally, in a non-word detection task, participants determined whether a sentence in one of these two syntactic forms contained only real words or a non-word. BOLD signal associated with the syntactic contrast increased in the left posterior inferior frontal gyrus in non-word detection and in a widespread set of areas in the other two tasks. We conclude that the BOLD activity in the left posterior inferior frontal gyrus reflects syntactic processing independent of concurrent cognitive operations and the more widespread areas of activation reflect the use of strategies and the use of the products of syntactic processing to accomplish tasks.
Who are we missing and why

The concept of "missing" is defined as failure to diagnose cancer before it has spread beyond the organ of origin. Data are presented for the 11 sites at which cancer occurs most frequently in the United States. There is a clear association between the survival of patients with cancer of a particular site and the percentage of cancers of that site diagnosed in a localized stage. However, the reasons for variation in the proportion of cases discovered while localized, which varies from 79% for uterine corpus to 12% for pancreas, appear to be varied and complex. Available data suggest that the nature of the tumor-host relationship and metastatic potential of the neoplasm are probably more important than alertness on the part of the patient and the physician, and probably have a more profound influence on stage of disease at diagnosis than currently available screening techniques.
Postural control of shell position by the abdomen of the hermit crab, Pagurus pollicarus. III. Analysis of movements and calculations of forces exerted by the muscles

Experiments with a transparent plastic snail shell indicated that the hermit crab carries the columella in the crook of its bent abdomen. There are three components to the normal curvature of the abdomen in the region of the third segment, a ventroflexion of 30°, a pitch to the right of 10°, and a clockwise rotation of 20° of the whole abdomen about the thoracic-abdominal junction. The forces and bending moments produced by the ventral superficial muscles were estimated from the sizes of the muscles, their position on the circumference of the abdomen, the amplitudes of the EJPs of the motoneurons, and their firing frequency. These calculations are in reasonable agreement with the behavioral measurements.
DONOR BINDING ENERGY IN TWO DIMENSIONS

We calculate numerically the binding energy of an electron bound to a proton in two-dimensional electron gas. Unlike the case in three dimensions, in 2D the binding energy is nonzero for all values of electron density.
Rayleigh-Ritz variational calculations of real-metal-surface properties

One-parameter variational calculations, employing different Kohn-Sham-type energy functionals of the density, are performed to determine the surface energy, relaxation dipole barrier, and work function for the most densely packed crystal faces of 12 simple metals (Al, Pb, Zn, Mg, Li, Ca, Sr, Ba, Na K, Rb, and Cs). The variational single-particle wave functions used are those generated from the linear-potential model, and the surface-energy functionals considered are those within the local-density approximation (LDA) for exchange and correlation, and the LDA with wave-vector analysis and gradient-expansion corrections. Both the first density-gradient correction coefficients due to Geldart-Rasolt, and the first and second gradient coefficients of Gupta-Singwi are employed in the determination of these properties. A comparative study of these gradient expansions and wave-vector-analysis corrections to the LDA exchange-correlation energy is also performed for jellium metal surfaces. The ions of the crystal are included via the Ashcroft pseudopotential, and a general and exact expression for the work function, including band-structure effects, is derived for the case when the ionic lattice is represented by such local pseudopotentials. The results of the primarily analytic calculations indicate that the bounds obtained within the LDA are superior to the perturbative results of Lang and Kohn, and that it is necessary to include corrections to the LDA value of the exchange-correlation energy if results comparable to existing experimental values are to be obtained. For medium- and low-density metals, the energy functionals with the wave-vector and gradient-expansion corrections lead to essentially equivalent results and closely approximate the experimental values. Although all three energy functionals lead to accurate results for the high-density metals (with the exception of Pb), the gradient-expansion values are generally superior. The results for the surface dipole barrier demonstrate that the density profile at real-metal surfaces is substantially different from that at the surface of jellium metal. The corresponding work functions obtained are, however, similar to the jellium-model values and fairly insensitive to the choice of energy functional employed. These results for the work functions compare well with polycrystalline metal experimental values.
Role of Bim in Diallyl Trisulfide-Induced Cytotoxicity in Human Cancer Cells

The aim of this study was to investigate the effect of garlic constituent diallyl trisulfide (DATS) on the cell death signaling pathway in a human breast cell line (MDA-MB-231). We observed that DATS (10–100 μM) treatment resulted in a dose- and time-dependent cytotoxicity. Treatment of MDA-MB-231 cells with a cytotoxicity inducing concentration of DATS (50–80 μM) resulted in an increase in the intracellular level of reactive oxygen species (ROS). Data from assay with MitoSOX ™ Red reagent suggest that mitochondria are the main source of ROS generation during DATS treatment. DATS-induced oxidative stress was detected through glutaredoxin (GRX), a redox-sensing molecule, and subsequently GRX was dissociated from apoptosis signal-regulating kinase 1 (ASK1). Dissociation of GRX from ASK1 resulted in the activation of ASK1. ASK1 activated a downstream signal transduction JNK (C-Jun N-terminal kinase)-Bim pathway. SP600125, a JNK inhibitor, inhibited DATS-induced Bim phosphorylation and protected cells from DATS-induced cytotoxicity. Our results indicate that the cytotoxicity caused by DATS is mediated by the generation of ROS and subsequent activation of the ASK1-JNK-Bim signal transduction pathway in human breast carcinoma MDA-MB-231 cells.
The Yale-Brown-Cornell Eating Disorder Scale: development, use, reliability and validity

Patients with eating disorders present with a wide range of eating-related preoccupations and or rituals. Yet, eating disorder assessments traditionally have measured a finite number of specific eating-disordered thoughts or actions. The current work presents a new instrument, the Yale-Brown-Cornell Eating Disorder Scale (YBC-EDS), that does not limit assessment to a particular set of eating-related concerns or behaviors. Rather, it assesses the severity of illness associated with an individual's unique symptomatology. Reliability and validity of this new, clinician-rated instrument was tested in two independent samples of DSM-III-R eating disorder patients. The YBC-EDS eight-item scale assessing severity of preoccupations and rituals, and a set of six provisional items for assessing motivation for change were both frequently endorsed and found to have excellent interrater reliability. Internal consistency was shown to be good for the set of eight core items and the set of six items related to motivation for change. The eight-item scale demonstrated aspects of convergent validity with other assessments of eating disorder symptomatology. The set of six provisional items for assessing motivation for change was inversely related to measures to diet restriction, drive for thinness, and body dissatisfaction. This paper presents the eight-item Yale-Brown-Cornell Eating Disorder Scale for assessing illness severity in eating-disordered patients with an extensive range of symptomatology. An accompanying set of six provisional items for assessing motivation for change are also presented. Initial findings showed excellent reliability and indications of validity for both the eight-item YBC-EDS and the set of six provisional items.
Sound localization in chinchillas. I: Left/right discriminations.

Abstract The ability of chinchillas to localize sound was examined behaviorally using a conditioned avoidance procedure in which the animals were trained to discriminate left from right sound sources. Their minimum audible angle was 15.6° for 100-ms broadband noise making them one of the more accurate rodents, although they are not as accurate as primates and carnivores. Thresholds obtained for filtered noise stimuli demonstrated that chinchillas are equally accurate in localizing either low- or high-frequency noise. Further, they are able to use both interaural phase-difference and interaural intensity-difference cues as demonstrated by their ability to localize both low- and high-frequency pure tones. Finally, analysis of the chinchilla retina supports the hypothesis that the role of auditory localization in directing the eyes to sound sources played a role in the evolution of auditory spatial perception.
Predictors of remission in DSM hypochondriasis

Although hypochondriasis is generally believed to be a chronic and refractory disorder, relatively little is known about its natural history and course. Based on a cognitive/perceptual model of hypochondriasis, we hypothesized that the disorder would be more chronic in patients who both amplify benign bodily symptoms and tend to attribute them to disease. Thirty-eight patients with DSM hypochondriasis were assessed with a structured, diagnostic interview and self-report questionnaire. A logistic regression model containing sociodemographic characteristics and a 3-way interaction term composed of the tendency to amplify bodily sensations, the tendency to attribute common symptoms to disease, and somatization (all measured at inception) correctly classified the remission status of 81.6% of the patients at follow-up 4 years later. These results suggest that patients who somatize, who are amplifiers of bodily sensation, and those who tend to attribute ambiguous symptoms to disease have more chronic and more refractory hypochondriasis. It is the co-occurrence of these cognitive and perceptual characteristics, rather than their occurrence individually, which predicts the persistence of this disorder.
Observation of Multiple Modes of Interior Density Turbulence in the TEXT-U Tokamak

Two distinct broadband modes of density turbulence propagating in the electron drift direction are simultaneously observed, in the first complete measurement of the wave number frequency spectrum $S(k,\ensuremath{\omega})$ in the interior of the TEXT-U tokamak plasma. A drift wave-type mode with a peak in the wave number spectrum at ${k}_{\ensuremath{\theta}}\ensuremath{\sim}4.5\mathrm{cm}{}^{\ensuremath{-}1}$ is found on both sides of the magnetic axis. A long-wavelength mode with ${k}_{\ensuremath{\theta}}\ensuremath{\le}2\mathrm{cm}{}^{\ensuremath{-}1}$ is found only on the low field side of the tokamak. The results resolve apparent discrepancies in previous turbulence measurements. Confinement properties of TEXT-U are consistent with the transport predicted by the observed drift wave-type ${\overline{k}}_{\ensuremath{\theta}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}3\mathrm{cm}{}^{\ensuremath{-}1}$.
Ischemic preconditioning preserves mitochondrial membrane potential and limits reactive oxygen species production

Abstract Background Mitochondrial superoxide radical (O 2 •¯ ) production increases after cardiac ischemia/reperfusion (IR). Ischemic preconditioning (IPC) preserves mitochondrial function and attenuates O 2 •¯ production, but the mechanism is unknown. Mitochondrial membrane potential (mΔΨ) is known to affect O 2 •¯ production; mitochondrial depolarization decreases O 2 •¯ formation. We examined the relationship between O 2 •¯ production and mΔΨ during IR and IPC. Materials/methods Rat hearts were subjected to Control or IPC. Mitochondria were isolated at end equilibration (End EQ), end ischemia (End I), and end reperfusion (End RP). mΔΨ was measured using a tetraphenylphosphonium electrode. Mitochondrial O 2 •¯ production was measured by electron paramagnetic resonance using DMPO spin trap. Cytochrome c levels were measured using high-pressure liquid chromatography. Results IPC preserved mΔΨ at End I (−156 ± 5 versus −131 ± 6 mV, P versus −155 ± 2 mV, P 2 •¯ production (2527 ± 221 versus 3523 ± 250 AU/mg protein, P versus 269 ± 16 picomoles/mg protein, P versus 33% ± 7%, P versus 28% ± 1%, P Conclusion We conclude that IPC preserves mΔΨ, possibly by limiting disruption of mitochondrial inner membrane. IPC also decreases mitochondrial O 2 •¯ production and preserves mitochondrial ultrastructure after IR. While it was previously held that slight decreases in mΔΨ decrease O 2 •¯ production, our results indicate that preservation of mΔΨ is associated with decreased O 2 •¯ and preservation of cardiac function in IPC. These findings indicate that the mechanism of IPC may not involve mΔΨ depolarization, but rather preservation of mitochondrial electrochemical potential.
Reciprocity in the green woodhoopoe (Phoeniculus purpureus)

Abstract Green woodhoopoes ( Phoeniculus purpureus ) exhibit behaviours that appear to meet all the criteria of reciprocity. In this species social units typically are composed of one breeding pair plus a variable number of helpers. A helper (X) that feeds nestling Y often is repaid by Y via Y's critical assistance in the acquisition of territorial ownership and breeding status by X; Y later also feeds the offspring of X. This pattern follows whether or not X and Y are related. Unrelated adult woodhoopoes of the same sex also may merge to form new social units, with the younger, lower ranking bird helping the older to acquire and retain territorial space. Later, it also provides care for the older bird's offspring. It is here suggested that a population structure based on a combination of cooperatively-breeding groups and high rates of mortality have favoured the evolution of reciprocal exchanges between unrelated individuals.
Monitoring by epifluorescence microscopy of organelle DNA fate during pollen development in five angiosperm species

The fates of mitochondrial and plastid nucleoids during pollen development in six angiosperm species (Antirrhinum majus, Glycine max, Medicago sativa, Nicotiana tabacum, Pisum sativum, and Trifolium pratense) were examined using epifluorescence microscopy after double staining with 4',6-diamidino-2- phenylindole (DAPI) to stain DNA and with a potentiometric dye (either DiOC7 or rhodamine 123) for visualization of metabolically active mitochondria. From the pollen mother cell stage to the microspore stage of pollen development, mitochondria and plastids both contained DNA detectable by DAPI staining. However, during the further maturation preceding anthesis, mitochondrial DNA became undetectable cytologically in either the generative or the vegetative cell of mature pollen; even in germinated pollen tubes containing hundreds of metabolically active mitochondria undergoing cytoplasmic streaming, vital staining with DAPI failed to reveal mitochondrial DNA. By the mature pollen stage, plastid DNA also became undetectable by DAPI staining in the vegetative cell. However, in the generative cell of mature pollen the timing of plastid DNA disappearance as detected by DAPI varied with the species. Plastid DNA remained detectable only in the generative cells of pollen grains from species known or suspected to have biparental transmission of plastids. The apparent absence of cytologically detectable organelle genomes in living pollen was further examined using molecular methods by hybridizing organelle DNA-specific probes to digests of total DNA from mature pollen and from other organs of A. majus and N. tabacum, both known to be maternal for organelle inheritance. Mitochondrial DNA was detected in pollen of both species; thus the cytological alteration of mitochondrial genomes during pollen development does not correspond with total mtDNA loss from the pollen. Plastid DNA was detectable with molecular probes in N. tabacum pollen but not in A. majus pollen. Since the organelle DNA detected by molecular methods in mature pollen may lie solely in the vegetative cell, further study of the basis of maternal inheritance of mitochondria and plastids will require molecular methods which distinguish vegetative cell from reproductive cell organelle genomes. The biological effect of the striking morphological alteration of organelle genomes during later stages of pollen development, which leaves them detectable by molecular methods but not by DAPI staining, is as yet unknown.
Structure of poly(methyl methacrylate) chains adsorbed on sapphire probed using infrared-visible sum frequency generation spectroscopy.

We have studied the orientation of the train segments of a poly(methyl methacrylate) (PMMA) adsorbed layer at the CCl4−sapphire interface using surface-sensitive IR−visible sum frequency generation...
Studies on the hydrolysis and utilization of long chain acyl CoA thioesters by liver microsomes.

Acyl CoA thioester “hydrolase” activity exhibited by liver microsomal preparations using a spectrophotometric assay for released CoA has been shown to be a composite of several enzymatic reactions. Pig liver microsomes form a considerable amount of triacylglycerol from endogenous precursors, with essentially all acyl groups being incorporated into the 1,3 positions. Rat and rabbit liver microsomes form very little triacylglycerol under the same conditions. The true acyl CoA hydrolase activity of pig liver microsomes is relatively insensitive to diisopropylfluorophosphate (DFP), whereas this compound strongly inhibits the rat and rabbit enzymes. The hydrolase remaining in the liver microsomes after DFP treatment is rapidly inactivated when incubated in the presence of substrate.
SHEAR INDUCED REDISTRIBUTION OF FLUID WITHIN A UNIFORMLY SWOLLEN NONLINEAR ELASTIC CYLINDER

Abstract The theory of mixtures is applied to the determination of equilibrium states of a solid-fluid mixture which is isolated from contact with a fluid bath. In the particular problem considered, a hollow rubber cylinder first undergoes unconstrained swelling in a fluid bath. The solid is homogeneously deformed to a larger cylindrical shape, the fluid is uniformly dispersed and the mixture is in a saturated equilibrium state. The mixture is then bonded to rigid impermeable membranes at its inner and outer surfaces. Rigid impermeable flat plates restrain motion at its ends. While the swollen length is held fixed, relative rotation of the membranes induces shear distortion in the rubber-fluid mixture. The resulting normal stresses cause a change in the mixture from its initial equilibrium state in which the system is homogeneously swollen but unsheared to a new equilibrium state in which there is radial variation of both the solid deformation and fluid density. A numerical example, using properties for a particular rubber-fluid mixture, shows that the volume of the mixture and the fluid density decrease near the inner wall of the cylinder and increase near the outer wall.
An improved method for determination of total hydroxyproline in urine.

Abstract A remarkably improved method of determination of total hydroxyproline in urine is proposed. It assures elimination of interfering chromogens or color inhibitors. By adequately controlling pertinent variables, excellent color stability and shortened hydrolysis period are achieved. The proposed method is simple, rapid, yet analytically accurate. It is possible to analyze a large number of samples during an 8-hour working day. The method would be ideal for routine applications.
Two-Dimensional Generalized Moment Representations and Rational Approximations of Functions of Two Variables

The Dzyadyk method of generalized moment representations is extended to the case of two-dimensional sequences and used to construct Pade approximants for functions of two variables.
Coupled Peierl's systems, a model for TTF-TCNQ☆

Abstract We study a model of two coupled quasi-one-dimensional Peierl's systems. Within Gorkov-type mean field theory, the model exhibits two phase transitions, the second one of which is accompanied by a periodicity change in the alternating chain direction. The model explains qualitatively the 54 K and 49 K transitions in TTF-TCNQ.
DYNAMIC FRACTURE CHARACTERIZATION OF CERAMIC MATRIX COMPOSITES

On a utilise une procedure experimentale et numerique pour etudier la rupture dynamique de composites ceramiques SiC/particules de TiB 2 et Al 2 O 3 /trichites de SiC a temperature ambiante et a 1200°C
Three strategies to achieve uniform tensile deformation in a nanostructured metal

Abstract In nanostructured metals with grain sizes of the order of 100 nm, dislocation mechanisms remain dominant in controlling plastic deformation. These materials, similar to their coarse-grained counterparts that have been subjected to heavy cold work, can no longer go through the several strain hardening stages of normal metals and are hence susceptible to plastic instabilities such as necking in tension. For processing and applications, it is obviously important and often necessary to control such inhomogeneous plastic deformation. Here we demonstrate three strategies to achieve relatively large stable tensile deformation in nanostructured metals, using the pure Cu processed by equal channel angular pressing as a model. The first approach uses an in situ formed composite-like microstructure, such as a bimodal grain size distribution, to impart strain hardening to the material and attain large uniform tensile strains while maintaining the majority of the strengthening brought forth by nanostructuring. In the second route, deformation is conducted at low temperatures, such as 77 K. The material regains the ability to work harden due to suppressed dynamic recovery. Uniform elongation is achieved as a result, together with an elevated strength at the cryogenic temperature. The third method takes advantage of the elevated strain rate sensitivity of the flow stress of the nanostructured Cu, especially at slow strain rates. Using the stabilizing effects of strain rate hardening on tensile deformation, nearly uniform strains can be acquired in absence of strain hardening. We also discuss the deformation mechanisms involved in these approaches to assess their applicability to nanocrystalline metals with grain sizes well below 100 nm, where normal dislocation activities become severely suppressed.
What We Know About Historical Trends in Firm Location Decisions and Regional Shifts: Policy Issues for an Industrializing Animal Sector

The location of agricultural production has an important bearing on environmental quality. Local conditions such as climate, soils, and geology as well as existing levels of contaminants affect the environment's capacity to assimilate pollution from agriculture. In addition, special or highly valued resources such as productive estuaries and sole source aquifers exist in some regions and not in others. When changes in the spatial distribution of production are induced by industrialization of the food system, the nature and extent of environmental damages from agriculture change as well. The U.S. animal production and marketing system is undergoing significant structural change. This transformation has been underway for more than four decades, but it recently has accelerated. Farm structure is evolving from many dispersed crop-livestock operations to fewer, larger firms specializing in production of dairy, poultry, or hogs. Increasingly, producers are more closely integrated into marketing stages and are locating in clusters near processing facilities and specialized infrastructure (Pagano and Abdalla). As production has concentrated, the potential burden placed on local environments by animal wastes has increased, co tributing to water and air pollution, odors, nsect problems, and a number of other concerns. Providing useful information to decision makers concerned about the environmental ef-
Up-Regulation of Vasopressin mRNA in Paraventricular Hypophysiotrophic Neurons after Acute Immobilization Stress

Cellular levels of vasopressin (VP) and corticotropin-releasing factor (CRF) mRNAs were determined in the rat hypothalamic paraventricular nucleus after acute immobilization stress. Messenger RNA levels were measured by in situ hybridization histochemistry using 35S-labeled synthetic DNA oligonucleotide probes and quantitative autoradiography. Analysis of histograms related to density values revealed that two hours after immobilization the average cellular VP and CRF mRNA levels were significantly increased (145 +/- 30.3 and 68 +/- 21.3%, respectively, above control values). Moreover, the number of VP-expressing parvicellular neurons was doubled in stressed rats relative to controls. These results indicate that single acute immobilization stress is sufficient to up-regulate VP as well as CRF mRNA production in the hypothalamic CRF-neurosecretory system.
Application of very low pressure pyrolysis to combustion kinetics

A new technique has been developed for the study of individual steps in chemical reactions. Molecular pyrolysis is performed at very low pressure in a fused silica vessel in which a uniform temperature is maintained. The products are examined directly with a mass spectrometer. Controlled amounts of oxygen or other gases can be added in order to study oxidations or other reactions. Results are presented on the pyrolysis of 1, 1, 1-trichloroethane and of chloroform. The former compound decomposes through a simple unimolecular elimination of HCl. The observed low-pressure-pyrolysis data are in accord with a high-pressure rate law, k ∞ =10 13.8 10 −51.7/θ sec −1 . Chloroform pyrolysis has proved to be dependent on the gas-flow rate; in addition, wall catalysis modifies the decomposition rate. Products of chloroform pyrolysis are HCl plus, variously, C 2 Cl 4 , Cl 2 , CCl 4 , solid carbon, or at the highest temperatures (≈1000°C), SiCl 4 . Decomposition is greater in the presence of C 2 Cl 4 . Evidence is presented that the activation energy for the molecular elimination exceeds 56 kcal. Oxygen added to the products of pyrolysis of CHCl 3 yields a new pair of mass peaks at 63 and 65 AMU, possibly due to COCl + from phosgene—an expected product of the reaction of dichlorocarbene with O 2 . The solid-carbon film produced by pyrolysis of chloroform was removable by oxidation with a flow of molecular oxygen at low pressures at 1000°C.
Using dielectric spectroscopy to detect thermal hysteresis in frog muscle

Abstract Dielectric spectroscopy has been used to characterize a wide variety of physiological changes in biological systems. We show here how dielectric spectra taken during a temperature cycle can indicate the presence of subtle physiological changes in the tissue. We measured the impedance spectra of frog gastrocnemius muscle, in vivo, in the frequency range 1 Hz to 1 MHz for temperatures from about 10 °C up to a maximum value, Tmax, and back down to about 10 °C. The range of values for Tmax was from 20 °C to 42.5 °C. For frequencies below about 50 kHz we observed hysteresis for thermal cycling above Tmax = 35 °C. The impedance at 10 °C at the end of the run was significantly lower than the impedance at 10 °C at the start of the run, even after corrections had been made for the change in impedance with time of the exposed muscle. For Tmax = 42.5 °C thermal hysteresis was apparent at all frequencies. We speculate that the impedance decrease was due to subtle changes in the membrane glycocalyx above 35 °C and to membrane leakage above 40 °C. We conclude that thermal cycling of impedance spectra can provide a sensitive measure of structural change for any physical system, not just biological tissue.
Chronic urticaria in a 17-year-old patient with a past history of bowel disease.

HISTORY OF PRESENT ILLNESS The patient’s clinical course was characterized by daily outbreaks of urticaria for 5 months. The urticarial lesions began as erythematous, pruritic patches on the knees that would become more prominent in the early morning hours, then spread to the upper torso, back, and extremities, and resolve within 24 hours without residual skin hyperpigmentation. She had been seen and evaluated by her pediatrician, dermatologist, and allergist with no identifiable etiology. She was maintained on loratadine (10 mg in the morning), cimetidine (400 mg four times daily), hydroxyzine (25 mg at bedtime), with intermittent low-dose prednisone burst and tapers to curb urticaria outbreaks and pruritus. However, she continued to have urticarial lesions that were unresponsive to medication. She denied having urticarial lesions in the intertriginous areas or pressure sites. She denied photosensitivity. She developed acute lip and eyelid angioedema concurrent with urticaria after ingestion of red-colored ibuprofen tablets and red candies on two separate occasions. However, an elimination diet with a food diary failed to document any association with ingestion of particular foods, food-coloring agents, or preservatives. Review of systems was negative for fever, chills, arthralgias, abdominal pain, sexually transmitted diseases, menstrual irregularity, shortness of breath, wheezing, or cough.
Malate dehydrogenase: a higher molecular weight form produced by freeze-thaw treatment of pig heart supernatant enzyme.

Abstract Attempts to produce hybrids of pig heart supernatant and mitochondrial malate dehydrogenase with the use of guanidine hydrochloride, acid treatment, and freezethaw techniques have been unsuccessful. However, the freeze-thaw technique produced a catalytically active higher molecular weight form of supernatant malate dehydrogenase in the absence or presence of mitochondrial enzyme. The higher molecular weight of this artifact was established by gel filtration and gel electrophoresis criteria. The specific activity of the artifactual form of the enzyme appears to be close to that of native supernatant malate dehydrogenase.