cssi/SciSciGPT-SciSciNet huggingface dataset:
A study of the effect of adsorbed gas on the high-frequency resistance of copper wire ..

Effect of Adsorbed Gas on the High-frequency Resistance of a Loop of Copper Wire.\char22{}This resistance is known to be greater than would theoretically be expected if the surface layers have the same resistivity as the core. The experiments described were undertaken to determine whether this increased resistance is due to gas adsorbed by the surface layer of oxide. A square loop, 60 cm. on a side, was formed by enclosing copper wires inside of glass tubes connected to a vacuum pump, and after several hours' preliminary heating and pumping, the wire was glowed, and then its resistance for radio-waves of 20 meters length was found to increase in 20 minutes by several per cent., though the residual pressure was only ${10}^{\ensuremath{-}5}$ atm. After successive glowings the effect became progressively less as the oxide layer disappeared. With higher pressures the increase to an equilibrium value came more rapidly. These results indicate that the gas adsorbed by the copper-oxide layer does increase the resistance, and suggest that possibly copper wire whose surface is covered with a thin layer of metal such as tin, might have a lower high-frequency resistance than oxidized copper wire of the same size.
Mechanical and Electrical Oscillations in Cardiac Muscle of the Turtle

During contractures of the turtle ventricle rapid changes in length induce sinusoidal oscillations under isotonic conditions. They are due to delayed responses to stretching and release, which can be demonstrated also under isometric conditions. Oscillations of two distinct frequencies are produced under different conditions and are distinguished as high- and low-frequency oscillations. In depolarized muscles the frequency is such that the duration of one cycle is about the same as that of a normal twitch, while in high-Ca solutions the duration can be the same as in high-K solutions or about six times lower. As reported previously, twitches are followed by weak mechanical and electrical oscillations. Their frequency agrees with the high-frequency oscillations. The same effects can also be induced by stretching and release. It is suggested that the phenomena observed are due to feedback mechanisms which originate in the contractile mechanism. The high-frequency oscillations are similar to those observed previously in other muscles, particularly insect fibrillar muscle, and are not due to changes in Ca concentration. The other mechanisms involve the membrane and possibly the intracellular Ca stores.
Further considerations on combining earth rotation observations from different space geodetic systems

Additional results are presented concerning a study that consider improvements over present Earth Rotation Parameter (ERP) determination methods by directly combining observations from various space geodetic systems in one adjustment. Earlier results are extended, showing that in addition to slight improvements in accuracy substantial (a factor of three or more) improvements in precision and significant reductions in correlations between various parameters can be obtained (by combining Lunar Laser Ranging (LLR), Satellite Laser Ranging (SLR) to Lageos, and Very Long Baseline Interferometry (VLBI) data in one adjustment) as compared to results from individual systems. Smaller improvements are also seen over the weighted means of the individual system results. Although data transmission would not be significantly reduced, negligible additional computer time would be required if (standardized) normal equations were available from individual solutions. Suggestions for future work and implications for the new International Earth Rotation Service (IERS) are also presented.
New evidence for the role of the Sertoli cell and spermatogonia in feedback control of FSH secretion in male rats.

A study is presented evaluating the effect of selective germ cell depletion on regulation of plasma FSH concentrations in chronic vitamin A-deficient (VAD) male rats. Plasma FSH, LH and testosterone levels were measured to assess pituitary-testicular interaction and the specific activities of certain testicular enzymes were determined to evaluate seminiferous tubular function during genii cell reduction. By 130 days, the testicular effects of vitamin A deficiency were maximal and resulted in loss of all germinal elements beyond spermatogonia. However, Sertoli cells andLeydig cells appeared normal. Notably in the presence of an intact pituitary-testicular axis, as judged by a normal response to castration, plasma FSH levels in VAD rats were indistinguishable from age matched controls. Although plasma testosterone levels in VAD rats were significantly lower than normals, this was associated with a reduction in plasma LH as well. The physiologic significance of decreased androgen levels is not clear. At appr...
Numerical stability analysis for free surface flows

SUMMARY A systematic methodology of numerical stability is presented here in the study of numerical properties of mixed Eulerian‐Lagrangian schemes for the numerical simulation of non-linear free surface flows. Two different numerical schemes, i.e. a source‐doublet panel method and a desingularized method, are investigated. The present work provides theoretical foundations and applications for numerical stability analysis theory. The matrix stability method has been developed to obtain the spectral radii and normal modes associated with free surface discretization. Some examples considered illustrate the usefulness of this analysis. 1997 by John Wiley & Sons, Ltd. Int. j. numer. methods fluids 24: 893‐912, 1997.
Enantiomeric impurities in chiral catalysts, auxiliaries, and synthons used in enantioselective syntheses. Part 4

Abstract The enantiomeric purity of chiral reagents used in asymmetric syntheses directly affects the apparent reaction selectivity and the product’s enantiomeric excess. Herein, 46 recently available chiral compounds were evaluated in order to determine their actual enantiomeric compositions. They have not been assayed previously and/or have been introduced after 2006, when the last comprehensive evaluation of commercially available chiral compounds was reported. These compounds are widely used in asymmetric syntheses as chiral synthons, catalysts, and auxiliaries. The enantioselective analysis methods include HPLC approaches using Chirobiotic, Cyclobond and LARIHC series chiral stationary phases, and GC approaches using Chiraldex chiral stationary phases. Accurate, efficient assays for selected compounds are given. All enantiomeric test results were categorized within five impurity levels (i.e., 10%). Different batches of the same reagent from the same company can have different levels of enantiomeric impurities. Many of the reagents tested were found to have less than 0.1% enantiomeric impurities. Only one of the chiral compounds was found to have an enantiomeric impurity exceeding 10%.
Bubbles in the Near-Surface Ocean: Their Various Structures

Abstract Air is entrained by breaking waves to produce bubbles. A highly transient macrobubble cloud is first generated under the breaker, with larger bubbles returning sooner to the sea surface. Those remaining smaller bubbles are then dispersed by near-surface turbulent shear flows in a shallow layer immediately below the undulating sea surface. Bubbles in this layer are shown to be nearly suspended; moreover, vertical distributions of current velocity and bubble concentration within this layer are found to be similar. Both of these features are used to demonstrate that the observed bubble layer, being on the order of 1 m thick, is formed through the longitudinal dispersion process. In addition, isolated microbubble plumes that penetrate several times deeper than the bubble layer appear to be produced also by breaking waves; however, in this case breaking waves temporarily deflect the bubble layer.
Diagnosis and management of respiratory involvement in Hunter syndrome

Respiratory problems are frequently encountered by patients with Hunter syndrome and contribute to the premature mortality seen in individuals with the disease. Progressive deposition of glycosaminoglycans in the soft tissue of the throat and trachea is thought to be responsible for the airway dysfunction and obstruction, which characterize the syndrome. Other physical characteristics, including abnormalities in the shape and structure of the ribs, abdominal organ enlargement, short neck and immobile jaw, further contribute to the respiratory problems. New measurement systems specifically tailored to paediatric patients now allow clinicians to follow the progressive deterioration of lung function, which was previously challenging in this population. Sleep apnoea is another common feature of Hunter syndrome, which can lead to a reduction in oxygen saturation of the blood and severely disrupts sleep. In our clinic, continuous positive airway pressure (CPAP), in which inspired air at elevated pressure is delivered through a specially designed mask, has proved to be effective for reducing sleep apnoea in patients with Hunter syndrome. As a consequence of the anatomical and pathological changes in the upper airways of patients with Hunter syndrome, general anaesthesia - especially intubation - is a difficult and potentially high-risk procedure. Consequently, such procedures should be performed by an anaesthetist - ideally accompanied by a paediatric pneumologist/intensivist - with experience in managing patients with Hunter syndrome. Conclusion: Respiratory abnormalities are a major contributor to the premature mortality seen in Hunter syndrome. Treatment of these respiratory problems requires the careful attention of clinicians skilled in the recognition, diagnosis, management and treatment of Hunter syndrome.
Predicting the Pool Fire Vortex Shedding Frequency

It seems that the most talked-about session at the 1989 ASME Winter Annual Meeting was the open forum titled Some Unanswered Question in Fluid Mechanics (Trefethen and Panton, 1989). The interest in the session was stimulated by the fact that most of these fluid mechanics questions are pivotal also in the field of heat transfer. Indeed, on the first day of the Winter Annual Meeting, several participants to the Panel on Directions and Issues in Heat Transfer: An Agenda argued that the identification and facing of unanswered questions is essential to the process of intellectually revitalizing the field of heat transfer. In this note, the author wants to contribute to this process by facing one of the unanswered questions. It has been known for twenty years that fires pulsate with a regular frequency, releasing large annular vortices (coherent structures) from their bases. What is not known is why f{sup 2} {congruent} 2.3m/s{sup 2}/D describes the shedding frequency of pool-flame oscillation over more than three orders of magnitude of the flame base diameter, from 0.03 to 60 m
Fractionated plasma protein values in subacute thyroiditis.

Tiselius fractionation of plasma proteins was performed on 27 patients with subacute (granulomatous) thyroiditis. In 21 there was a significant elevation of the α2-globulin level and in 18 of these 21 there was a significant elevation of the fibrinogen level. Other findings of the fractionation of plasma proteins in subacute thyroiditis were: a decrease in the level of plasma albumin in 16 patients, and an elevation in the level of α1-globulin in 5, of beta-globulin in 2, of gamma-globulin in 12, and of fibrinogen in 19. In only 6 of 55 patients with Hashimoto’s disease, and in none of 30 patients with nontoxic adenomatous goiter were high values obtained for α2-globulin. In 6 of 35 patients with struma lymphomatosa the fibrinogen values were elevated. The erythrocyte sedimentation rate was increased in 18 of 20 patients in whom it was determined. The rate was elevated in 15 of 16 patients who had a high level of α2-globulin. The increase in the level of α2-globulin probably is largely due to the cataboli...
A stochastic model for the synthesis and degradation of natural organic matter. Part I. Data structures and reaction kinetics

Here we present a stochastic biogeochemical model for the formation, transformation and mineralization of natural organic matter (NOM). The model is agent-based, with each software agent representing a single molecule of defined composition. Molecular properties and reactivities are estimated from composition and environmental parameters. Environmental parameters including temperature, pH, light intensity, dissolved O2, moisture and enzyme activities are user controlled. Time is treated in discrete steps, and during each step potential reaction probabilities are evaluated for each molecule based on its structure and the environmental parameters. When reactions occur, the molecular composition is modified accordingly. The model uses small natural products and biopolymers for inputs, and the composition of the molecules produced is constrained only by the inputs and reaction stoichiometries, not by pre-defined structures. Example simulations using the program AlphaStep are presented, in which the breakdown of biopolymers and the condensation of small molecules both lead to molecular assemblages with elemental composition and average properties similar to those of aquatic NOM. This batch-reactor model can be expanded to include spatial information and environmental feedback.
Molecular characterization and comparative virulence of Beauveria bassiana isolates (Ascomycota: Hypocreales) associated with the greenhouse shore fly, Scatella tenuicosta (Diptera: Ephydridae)

Abstract Reports of natural infections of the insect pathogenic fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Hypocreales) in greenhouses and laboratory colonies of Scatella tenuicosta Collin (Diptera: Ephydridae), a nuisance pest and vector of plant pathogens, suggest the potential for using B. bassiana for microbial control of this pest. In this study we assessed the diversity of B. bassiana isolates found associated with a colony of shore flies and compared these isolates to two commercial B. bassiana strains. Microsatellite markers were used to assess genetic variation among fungal isolates from adults and pupae of S. tenuicosta, adults of Hexacola neoscatellae Beardsley (Hymenoptera: Figitidae), a hymenopteran parasitoid of S. tenuicosta, and algal food source in greenhouses. Twenty-seven single spore isolates were resolved into three distinct haplotypes using eight microsatellite markers. Two haplotypes were most common, comprising several strains collected from infected shore flies and parasitoids. The third haplotype was observed in only one strain from a shore fly pupa. Bioassays of a representative strain of each haplotype against third-instar larvae, pupae and adults of shore flies showed that adults were more susceptible to the fungus than the other two stages. Secondary pick up of inocula from sprayed pupae by adults resulted in 52% and 55% mortality from B. bassiana strains ST1 and ST2, respectively. Direct spray application on adults resulted in 91 and 94% mortality from these two strains, suggesting their potential as biological control agents against shore flies.
Association between Alopecia Areata, Psoriasis Vulgaris, Thyroid Disease, and Metabolic Syndrome

Although the association between alopecia areata (AA), psoriasis, and other autoimmune diseases has been well reported in the literature, an association with metabolic syndrome has not been reported. We present two young women with the combination of severe psoriasis, androgen excess, metabolic syndrome, thyroiditis, and AA. Both women ultimately progressed to treatment-resistant alopecia universalis. This constellation of autoimmunity and metabolic syndrome presents a therapeutic challenge while highlighting the need for full laboratory assessment of AA patients. Careful selection of biological treatment regimens may offer therapeutic benefit for both their psoriasis and AA while giving us experience with the newer biologics in AA.
Residual Estrogens in the Tissues of Fowl Treated with Dienestrol Diacetate

Abstract SYNTHETIC estrogens are now being used commercially to feminize male fowl and thereby to increase their market quality. It is desirable to obtain as much information as possible on the quantity of estrogens remaining in the edible tissues of treated birds. Since Lorenz and Bachman (1947) have shown that dienestrol diacetate, when fed at levels of .0033 to .01 percent of the diet, has the ability to increase the fat deposition in young cockerels, it might well be a very good hormone to use commercially if there is no appreciable amount of this estrogen remaining in the edible tissues. Bird et al., (1947) have demonstrated that in birds treated with dienestrol diacetate there is a negligible quantity of that substance left in the abdominal adipose tissue. Although these workers assayed edible tissues of 3 males that had been fed the dimethyl ether of hexestrol, they did not assay any of . . .
Antioxidant and Cytotoxic Effects of Bilirubin on Neonatal Erythrocytes

Bilirubin, the breakdown product of heme from erythrocytes, accumulates in the neonate in the first days of life. In recent years, the antioxidant properties of bilirubin have been demonstrated in vitro and in vivo, yet it is clear that bilirubin can be toxic to cells. To study the range in which bilirubin exerts its beneficial effect, we used erythrocytes derived from cord blood and incubated them with 0-60 mg/dL bilirubin combined with 3 g/dL BSA (bilirubin/BSA) to mimic physiologic and pathologic conditions. Oxidative stress was induced by incubating the erythrocytes with a solution of 0.6 mM H2O2 and 0.15 M CuSO4 to generate hydroxyl radical mediated injury. The loss of fluorescence of cis-parinaric acid and the degree of protein oxidation of erythrocyte membranes were assessed. Additionally, we determined erythrocyte membrane integrity, glucose-6 phosphate dehydrogenase activity, and adenosine triphosphatase activity before and after incubation with bilirubin/BSA. Incubation with bilirubin/BSA at concentrations up to 60 mg/dL and a bilirubin/BSA molar ratio of two was associated with dose-dependent protection of erythrocytes against lipid peroxidation. However, concentrations of bilirubin equal to or exceeding 30 mg/dL and a bilirubin:BSA ratio of one were associated with increased protein oxidation, decreased erythrocyte glucose-6 phosphate dehydrogenase and adenosine triphosphatase activity, and altered cell membrane integrity. We conclude that bilirubin, at physiologic concentrations, protects neonatal red blood cells against oxidative stress in the presence of physiologic concentrations of BSA but that bilirubin concentrations of 30 mg/dL or higher and a bilirubin:BSA ratio of greater than one are associated with significant cytotoxicity.
Multiple Broad-Spectrum Beta-Lactamase Targets for Comprehensive Surveillance

Real-time PCR testing for blaKPC, blaNDM, blaVIM, blaIMP, and blaCTX-M was performed on rectal swabs obtained from residents of two long-term acute-care facilities. While blaKPC was detected in 69/102 swabs (67.6%), testing for four other targets increased the positivity rate for a broad-spectrum β-lactamase to 73.5% (McNemar's P = 0.03).
Treatment of a Patient with Cervical Radiculopathy Using Thoracic Spine Thrust Manipulation, Soft Tissue Mobilization, and Exercise

While there is currently little evidence to suggest which non-operative treatment approach is best for the management of patients with cervical radiculopathy, emerging evidence suggests that these patients benefit from a multimodal treatment approach. The purpose of this case report is to describe the physical therapy management of a patient with cervical radiculopathy. Diagnosis was based on the patient's meeting three of the four criteria in the diagnostic test cluster currently used to identify patients with cervical radiculopathy. Treatment included thrust manipulation of the thoracic spine, soft tissue mobilization, and therapeutic exercise. After three visits, patient-perceived disability, as measured by the Patient-Specific Functional Scale, improved from 5/10 to 10/10. The Numeric Pain Rating Score decreased from 4.66/10 to 0/10. The patient rated his improvement as a very great deal better on the Global Rating of Change Scale. These clinically meaningful improvements were maintained at the 14-week follow-up. While a cause-and-effect relationship may not be established from a case report, a multimodal approach including thoracic spine manipulation, soft tissue mobilization, and therapeutic exercise was associated with decreased pain and perceived disability in a patient with cervical radiculopathy. Further research is needed to investigate benefits of the components of this approach.
Application of the Microtox system to assess the toxicity of pesticides and their hydrolysis metabolites.

In this study, we used the Microtox analyzer to determine the relative microbial toxicities of some pesticides and their metabolites. Because hydrolysis is a significant step in the chemical and microbial degradation of pesticides in soil, the principal focus of this investigation was on hydrolytic metabolites
[Comment on “Magnetospheric research and the history of the solar system” by Hannes Alfvén]

Alfven's recent summary “Magnetospheric Research and the History of the Solar System” (Eos, October 23, 1984, pp. 769–770) contains a statement concerning the nature of Saturn's rings which might mislead readers who are unfamiliar with the current status of ring research. Saturn's rings do not consist of 10,000 or 100,000 separate ringlets. Recent reduction of centimeter wavelength occultation measurements by Voyager at 1-km radial resolution show the presence of 21 gaps in the classical ring system comprised of rings A, B, and C. Thus there are, in fact, 22 rings in the main system (G. L. Tyler, P. A. Rosen, and E. A. Marouf, “Classification of Saturn's Ring Features,” presented at the 16th Annual Division of Planetary Sciences of the American Astronomical Union meeting, October 8–12, 1984).
Embryo development in four Datura species following self and hybrid pollinations.

Englislh plantain is a long-day plant developing flowers when exposed to 15 or more long days or to 9 or more days of continuous illumination. Plants have been kept for over 14 months in the vegetative condition by continuous exposure to short-day conditions. Plantain will develop flowers when exposed to 25 long days even though this treatment is not continuous but is interrupted by 10 or 20 consecutive short days. The changes which occur during "partial" photoperiodic induction apparently persist during relatively long periods of exposure to light and dark periods whose lengths are not favorable for flowering. Plantain exposed to photoperiodic cycles (other than of 24 hr. duration) flowered when exposed to cycles consisting of short light (14 hr. or less) and short dark periods (10 hr. or less), long light and short dark periods, and long light and long dark periods; but remained vegetative when exposed to cycles consisting of short light and long dark periods. It is suggested that in the development of floral structures of this long-day plant, there may be two reactions which occur during exposure to light. The first reaction is unstable and is destroyed during darkness, while the second is relatively permanent and when established will persist during long periods unfavorable to the stimulation of flowering. It is further suggested that the second reaction occurs after the primarv reaction has reached a "threshold" value, and upon reaching sufficient intensity results in floral development.
Near simultaneous release of classical and peptide cotransmitters from chromaffin cells

Adrenal chromaffin cells are an important part of the neuroendocrine system and under stressful conditions release catecholamines into the blood, thus regulating many physiological processes. In addition to the catecholamines, chromaffin cells also synthesize a range of peptides, including neuropeptide Y. Although the catecholamines and peptides are both contained within dense core granules, whether they are copackaged is less clear. Here, I investigate whether a single dense core granule can be loaded with both types of transmitter molecules. Using amperometry and FMRFamide tagging, I simultaneously measure the secretion of the catecholamines and a neuropeptide from mouse chromaffin cells in vitro. I find that fusion of a single dense core granule releases both types of transmitters into the extracellular space. Significant amounts of peptide escape from a fusing granule in 1-2 ms: almost as rapidly as the catecholamines. This suggests that the kinetics of peptide secretion might not be as sluggish as sometimes thought.
Diagnosis and management of ambiguous genitalia.

The diagnosis and management of a newborn with ambiguous genitalia is a diagnostic challenge. Rapid medical evaluation is necessary to uncover and treat potentially life-threatening illnesses, and to allay the psychological stress placed on new parents awaiting announcement of their baby’s sex of rearing. Understanding the mechanisms of sexual differentiation can facilitate this task for the physician faced with this dilemma. This article reviews these mechanisms and suggests a logical approach to handling the work-up and treatment plan.
Dichloro(phthalocyanino)silicon

Abstract : Two convenient syntheses for PcSiCl2 are reported which are based on the use of o-cyanobenzamide and 1, 3-di-iminoisoindoline. In addition techniques are given for the recrystallization of this dichloride and for its facile conversion to PcSi(OH)2. (Author)
Value Relevance of Unrealized Foreign Currency Translation Gains and Losses

This study uses an equity valuation model to investigate the extent to which SFAS No. 52 unrealized foreign currency translation gains and losses are reflected in levels of equity security prices. Equity security price is used as the dependent variable in our selected model. Book value of equity (adjusted for the cumulative translation gain or loss), earnings, and cumulative translation gains and losses are used as independent variables. Our results indicate that, generally, translation gains and losses are valued, but losses have a greater impact than gains and the value seems to change over time in setting the levels of equity share prices of USbased MNCs. On a pooled basis, the results are clearly statistically significant, although the statistical significance of the results appears to vary with the annual time period examined. Our results are consistent with the SFAS No. 52 intention that these gains and losses be treated as unrealized as the net exposure is considered long‐term in nature for foreign currency functional currency subsidiaries. Our results appear consistent with extant literature suggesting that unrealized foreign currency translation gains and losses are directly valued ‐ although not dollar for dollar ‐ in a manner similar to earnings (i.e., unrealized gains are associated with positive equity returns and unrealized losses are associated with negative equity returns).
Outcomes of general anesthesia for noncardiac surgery in a series of patients with Fontan palliation.

Summary Objectives To describe the experience of a single, tertiary care institution in the care of patients with Fontan physiology undergoing anesthesia for noncardiac surgery. Background The Fontan procedure was developed in 1971 to palliate patients with univentricular cardiac physiology leading to long-term survival of these patients, who may now present as adults for noncardiac surgery. Methods We retrospectively reviewed the medical records of Fontan patients 16 years and older who underwent general anesthesia for noncardiac surgery at Mayo Clinic in Rochester, Minnesota. Preoperative data, perioperative course, intraoperative and postoperative hemodynamic, pulmonary, cardiovascular, and renal complications were described. Results Thirty-nine general anesthetics were administered to 31 patients for noncardiac surgery after Fontan palliation. Perioperative complications occurred in 12 of the 39 (31%) noncardiac surgeries, and there was one postoperative death that occurred on day 13 after ventral hernia repair. The two patients who had complications that did not resolve (long-term dialysis and death) had ejection fractions well below the mean for the group (22% and 28%). Conclusion It may be more appropriate for Fontan patients to undergo anesthesia for noncardiac surgery in a tertiary institution, particularly patients with an ejection fraction of <30%. Intraoperative arterial blood pressure monitoring and overnight admission are likely appropriate for most cases.
ClinicalKey: A Smarter and Faster Way to Answer Clinical Questions? A Review

ClinicalKey is an online search engine that is marketed as a premier product because it provides search features and attributes that are only partially available in similar online search engines. The attributes include speed, trustworthiness, and comprehensive coverage of clinical topics. ClinicalKey subscriptions are available for individuals and institutions. Hospital, academic, and special libraries will find the content useful to support their clinical staff. The content includes patient information. This information is important as clinicians are increasingly striving to assist in educating their patients so that they become actively involved in their healthcare decisions. This review describes the content and major features of ClinicalKey and provides information concerning how the system can be enhanced.
Methanobactin, a Copper-Acquisition Compound from Methane-Oxidizing Bacteria

Siderophores are extracellular iron-binding compounds that mediate iron transport into many cells. We present evidence of analogous molecules for copper transport from methane-oxidizing bacteria, represented here by a small fluorescent chromopeptide (C45N12O14H62Cu, 1216 daltons) produced by Methylosinus trichosporium OB3b. The crystal structure of this compound, methanobactin, was resolved to 1.15 angstroms. It is composed of a tetrapeptide, a tripeptide, and several unusual moieties, including two 4-thionyl-5-hydroxy-imidazole chromophores that coordinate the copper, a pyrrolidine that confers a bend in the overall chain, and an amino-terminal isopropylester group. The copper coordination environment includes a dual nitrogen- and sulfur-donating system derived from the thionyl imidazolate moieties. Structural elucidation of this molecule has broad implications in terms of organo-copper chemistry, biological methane oxidation, and global carbon cycling.
Use of universal function approximation in variance-dependent surface interpolation method: An application in hydrology

Variance dependent stochastic interpolation approaches such as kriging are widely recognized as standard stochastic methods for interpolation of geophysical and hydrologic variables. Deterministic weighting and stochastic interpolation methods are the most frequently used methods for estimating missing rainfall values at a gage based on values recorded at all other available recording gages. Traditional kriging has a major limitation due to the need for an a priori definition of a mathematical function for a semivariogram that might fit the surface to be interpolated. Use of the universal function approximator, artificial neural network (ANN), as a replacement to fitted authorized semivariogram model within ordinary kriging is investigated in the current study. The revised ordinary kriging is used for estimation of missing precipitation data at a rainfall gaging station based on data recorded at all other available gaging stations. Historical daily precipitation data obtained from 15 rain gaging stations from a temperate climatic region, Kentucky, USA, is used to test the improvised method and derive conclusions about the efficacy of this method. Results suggest that use of universal function approximator such as ANN within a kriging has several advantages over ordinary kriging.
Epigamic display and unique mating position in Wyeomyia arthrostigma (Diptera: Culicidae).

The mating behavior ofWyeomyia arthrostigma is more complex than that reported forW. smithii. Like some other genera in the tribe Sabethini, flyingW. arthrostigma males approach females perching on vertical sticks. A male aligns himself next to a female by seizing her wing and flipping sideways to land next to her, rather than beneath her. He then performs a series of abdominal bobbing movements, the pair achieves superficial genital coupling while the male's proboscis rotates and snaps down, and the antennae spread farther apart. Finally, the pair shifts to full copulation, and in this phase insemination occurs. In the copulatory position the abdomens of male and female are almost at right angles to each other, made possible by a twisting of the male's terminal segments. The nature of the mating process and its similarity to some elements ofSabethes andTopomyia mating indicate that males may be performing a courtship display.
Partial purification and some properties of phenylalanine ammonia-lyase of tobacco (Nicotiana tabacum).

Abstract The enzyme responsible for the first step in the synthesis of phenolic compounds in tobacco, l -phenylalanine ammonia-lyase, was purified approximately 200-fold from leaves of Nicotiana tabacum var. Burley 21. The purest preparation was at least 70 per cent homogenous as defined by disc electrophoresis. The optimal pH for the reaction was between 8·0 and 8·6. At pH 7·4, the K m for the substrate l -phenylalanine was 1·6 × 10 −4 M and at pH 8·55 it was 2·2 × 10 −4 M. d -Phenylalanine, l -tyrosine, m -tyrosine, o -tyrosine, and dihydroxyphenylalanine were not deaminated by the enzyme. Sulfhydryl compounds caused a significant stimulation of activity, but no cofactor requirements were found. The enzyme was sharply inhibited by trans -cinnamic acid, in a competitive manner, with a K i of 3·1 × 10 −5 M at pH 7·1. Other phenolic inhibitors included o -coumaric acid, o -tyrosine, and quercetin. It is suggested that trans -cinnamic acid may play a role in vivo in regulating biosynthesis of phenolic compounds in tobacco.
Regulating the Balance between Peroxisome Proliferator-activated Receptor γ and β-Catenin Signaling during Adipogenesis A GLYCOGEN SYNTHASE KINASE 3β PHOSPHORYLATION-DEFECTIVE MUTANT OF β-CATENIN INHIBITS EXPRESSION OF A SUBSET OF ADIPOGENIC GENES

The differentiation of preadipocytes into adipocytes requires the suppression of canonical Wnt signaling, which appears to involve a peroxisome proliferator-activated receptor γ (PPARγ)-associated targeting of β-catenin to the proteasome. In fact, sustained activation of β-catenin by expression of Wnt1 or Wnt 10b in preadipocytes blocks adipogenesis by inhibiting PPARγ-associated gene expression. In this report, we investigated the mechanisms regulating the balance between β-catenin and PPARγ signaling that determines whether mouse fibroblasts differentiate into adipocytes. Specifically, we show that activation of PPARγ by exposure of Swiss mouse fibroblasts to troglitazone stimulates the degradation of β-catenin, which depends on glycogen synthase kinase (GSK) 3β activity. Mutation of serine 37 (a target of GSK3β) to an alanine renders β-catenin resistant to the degradatory action of PPARγ. Ectopic expression of the GSK3β phosphorylation-defective S37A-β-catenin in Swiss mouse fibroblasts expressing PPARγ stimulates the canonical Wnt signaling pathway without blocking their troglitazone-dependent differentiation into lipid-laden cells. Analysis of protein expression in these cells, however, shows that S37A-β-catenin inhibits a select set of adipogenic genes because adiponectin expression is completely blocked, but FABP4/aP2 expression is unaffected. Furthermore, the mutant β-catenin appears to have no affect on the ability of PPARγ to bind to or transactivate a PPAR response element. The S37A-β-catenin-associated inhibition of adiponectin expression coincides with an extensive decrease in the abundance of C/EBPα in the nuclei of the differentiated mouse fibroblasts. Taken together, these data suggest that GSKβ is a key regulator of the balance between β-catenin and PPARγ activity and that activation of canonical Wnt signaling downstream of PPARγ blocks expression of a select subset of adipogenic genes.
The Na,K-ATPase of nervous tissue.

Abstract The Na,K-ATPase has been only partially purified from nervous tissue, yet it is clear that two forms (and α +) of the catalytic subunit are present. α is a component subunit of the glial Na,K-ATPase, which has a relatively low affinity for binding cardiac glycosides and α + has been identified as a subunit of the Na,K-ATPase which has relatively high affinity for cardiac glycosides. The α + form may also be sensitive to indirect modulation by neurotransmitters or hormones. The ratio of α + /α changes in the nervous system during development, and α + appears to be the predominant species in adult neurones. Changes in Na,K-ATPase activity have been associated with several abnormalities in the nervous system, including epilepsy and altered nerve conduction velocity, but a causal relationship has not been definitively established. Although the Na,K-ATPase has a pivotal role in Na + and K + transport in the nervous system, a special role for the glial Na,K-ATPase in clearing extracellular K + remains controversial.
Kinetics, brain uptake, and receptor binding characteristics of flurazepam and its metabolites.

The benzodiazepine derivative flurazepam (FLZ) is widely used as a hypnotic, but the relative contributions of FLZ and its metabolites desalkylflurazepam (DA-FLZ), hydroxyethylflurazepam (ETOH-FLZ), and flurazepam aldehyde (CHO-FLZ) to overall clinical activity remain uncertain. A single 20 mg/kg dose of FLZ·HCl was administered to mice, with plasma and brain concentrations of FLZ and metabolites determined during 5 h after dosage. Brain and plasma concentrations of FLZ were maximal at 0.5 h after dosage, then declined rapidly in parallel, whereas those of DAFLZ were maximal at 2 h, then declined slowly. Concentrations of ETOH-FLZ, the most polar metabolite, were maximal at 0.5 h, and were undetectable after 3 h. Little CHO-FLZ was detected in either brain or plasma. A single 30-mg oral dose of FLZ·HCl was given to 18 human volunteers, with plasma levels determined over 9 days. FLZ was detected in plasma at low concentrations for no more than 3 h after dosage. ETOH-FLZ concentrations were higher and persisted for 8 h after dosage. CHO-FLZ reached intermediate peak levels and was present longer than FLZ or ETOH-FLZ. In contrast, DA-FLZ achieved the greatest peak concentrations, occurring at 10 h after dosage. Levels declined very slowly, with a mean half-life of 71.4 h, and were still detectable 9 days after FLZ dosage. Plasma free fractions (percent unbound) in mice were 40.3, 51.4, and 25.0% for FLZ, ETOH-FLZ and DA-FLZ, respectively; in humans, values were 17.2, 35.2, and 3.5%, respectively. Brain:free plasma ratios in mice for the three compounds were 8.17, 2.21 and 7.01, and were correlated with HPLC retention times, an index of lipophilicity (r=0.90), suggesting passive distribution from plasma to brain. In vitro specific binding affinities (Ki) in rat brain membranes for FLZ, ETOH-FLZ, DA-FLZ, and CHO-FLZ were 12.7, 16.2, 0.85, and 10.6 nM, respectively. Thus after a single 20 mg/kg dose of FLZ in mice, DA-FLZ brain concentrations greatly exceeded its Ki, while FLZ and ETOH-FLZ levels relative to their own Ki values are one or more orders of magnitude lower. Since brain:free plasma ratios and binding characteristics for benzodiazepines appear similar in rodents and humans, similar conclusions can be drawn for humans based on pharmacokinetic and protein binding data. Pharmacodynamic effects after a single dose of FLZ in mice and humans are largely attributable to DA-FLZ, consistent with behavioral studies comparing relative potencies of metabolites.
Relaxation dynamics of entangled and unentangled multiarm polymer solutions: Experiment

Relaxation dynamics of several model A3−A−A3 multiarm 1,4-polybutadiene melts and solutions are investigated experimentally using small amplitude oscillatory shear rheometry over a broad temperatur...
Chondrosarcoma of mandible misdiagnosed as chondromyxoid fibroma

Abstract The diagnosis of chondrosarcoma of the jaws is often difficult due to the often indistinct boundaries between benign and malignant chondromatous tumors. In view of the often considerable variation in histological characteristics within a tumor, repeated biopsies and step sections through a specimen are recommended in difficult cases. This paper is a follow-up of the case described by Davis & Tideman (1978) in this journal.
An adaptive constraint method for paraunitary filter banks with applications to spatiotemporal subspace tracking

This paper presents an adaptive method for maintaining paraunitary constraints on direct-form multichannel finite impulse response (FIR) filters. The technique is a spatiotemporal extension of a simple iterative procedure for imposing orthogonality constraints on nearly unitary matrices. A convergence analysis indicates that it has a large capture region, and its convergence rate is shown to be locally quadratic. Simulations of the method verify its capabilities in maintaining paraunitary constraints for gradient-based spatiotemporal principal and minor subspace tracking. Finally, as the technique is easily extended to multidimensional convolution forms, we illustrate such an extension for two-dimensional adaptive paraunitary filters using a simple image sequence encoding example.
Identification and characterization of a novel hypertonicity-responsive element in the human aquaporin-1 gene.

The AQP1 gene is transcriptionally upregulated in response to hypertonicity. However, the molecular mechanism in hypertonicity-induced transcription in the AQP1 gene has been poorly understood. Here we report a novel hypertonicity response element (HRE) in the AQP1 gene. A critical cis-acting element to hypertonicity in the AQP1 promoter is located at −54 to −46 and the change from GCTCCCCCC to GCTTTCCCC completely abolished the hypertonic induction and osmotic response, thus implicating the importance of the first CC sequence in the region. Two prominent DNA–protein complexes were observed electrophoretic mobility shift assay (EMSA), and the band intensities in nuclear extracts from osmotically stressed cells were much higher than that of isotonic nuclear extracts. The EMSA supershift assay with anti-Sp1 antibody showed that two retarded bands did not bind to anti-Sp1 antibody, suggesting that the DNA binding proteins bound to the HRE are not Sp1 family proteins. These data suggest that the transcription of the AQP1 by hypertonicity in renal cells is upregulated by the interaction with putative DNA binding proteins to a novel HRE located at −54 to −46 in the AQP1 gene.
Liquid chromatography with tandem mass spectrometry-based proteomic discovery in aging and Alzheimer’s disease

Systems biology offers enormous potential to understand the complexity of human brain aging and neurodegenerative diseases. Proteomics has an important role in these investigations because of its unique strengths and because of the potential central pathogenic contribution of pathological protein to several of these diseases. Here we have reviewed the methods and presented some examples of liquid chromatography—electrospray ionization—tandem mass spectrometry— based proteomics, with and without quantification using isotope-coded affinity tags, in the investigation of aging and Alzheimer’s disease. As protocols and methods for improved quantitative high-throughput proteomics constantly improve, this approach will likely continue to provide deeper insight into human brain aging and neurodegenerative diseases.
National estimates of hospitalization charges for the acute care of traumatic brain injuries.

Primary objective: To estimate hospitalization charges for the acute care of traumatic brain injuries (TBIs) in the US and to identify factors associated with increased charges. Research design: Population-based descriptive study. Methods: The 1996 National Inpatient Sample was used, which contains all-payer data on hospital inpatient stays from 906 hospitals in 19 states. Multivariate linear regression with the log (meanþ1) charges as the dependent variable was used to identify factors associated with increased charges. Results: An estimated 254 500 TBIs required hospitalization in 1996 in the US, with $5.4 billion charged to treat these injuries during acute hospitalization. Patient age (up to 34 years), increasing severity of injury and urban teaching hospitals were associated with higher mean charges in multivariate analysis. Conclusions: Based on hospitalization rates, mean and total charges, segments of the population were identified that are likely candidates for injury prevention interventions.
K-shell ionization of intermediate-Z elements by 30-MeV/amu H, N, Ne, and Ar ions.

Cross sections for {ital K} x-ray production in solid targets ({ital Z}=13, 22, 26, 29, 32, 40, 42, 46, and 50) by 30-MeV/amu beams of H, N, Ne, and Ar were measured. The cross sections were determined by recording the spectra of {ital K} x rays with a Si(Li) detector in coincidence with beam particles detected in a microchannel plate assembly. The {ital K}-shell-ionization cross sections deduced from these data agree quite well with the predictions of the perturbed-stationary-state theory with energy loss, Coulomb deflection, and relativistic corrections. Detailed analyses of the projectile and target {ital Z} dependences of the cross sections were performed. Also, the relative intensities of {ital K} x rays from double {ital K}-shell ionization of the higher-{ital Z} targets are presented for N, Ne, and Ar projectiles.
Anomalous behavior in the spin polarization of low-energy secondary electrons from Gd(0001).

We have measured the spin-polarization spectrum of low-energy secondary electrons from the surface of thick single-crystalline Gd(0001) films grown on W(110). Below 1.5 eV an anomalous decrease in the polarization is observed and is attributed to the presence of the 4${\mathit{f}}^{8}$ states just above the vacuum level, which leads to increased emission of spin-down electrons. Between 1.5 and 7 eV the spin polarization remains nearly constant at about 33% (at 150 K), demonstrating that the phenomenon of polarization enhancement for low-energy secondary electrons is not universal. The observed large polarizations indicate that the completely polarized 4f electrons contribute significantly to the secondary-electron yield.
Infrared Measurements of Pristine and Disturbed Soils 2. Environmental Effects and Field Data Reduction

Abstract W e have expanded on previous methods for correcting thermal infrared field measurements for atmospheric downwelling radiance ( Salisbury and D'Aria 1992 ; Korb et al. 1996 ; Hook and Kahle 1996 ) by comparing the sensitivity of various input parameters (sample temperature, diffuse gold plate emissivity, and temperature) on this correction. We find that the sample temperature has the greatest influence on the applied atmospheric correction (cf. Nerry et al. 1990a Nerry et al. 1990b ; Labed and Stoll 1991 ), and we present a method in which the sample temperature is varied to minimize the residual atmospheric emission lines in the measured field emissivity spectra. Direct comparison of laboratory hemispherical reflectance measurements of wet-sieved and dry-sieved samples with these appropriately corrected field observations of undisturbed and disturbed soils, respectively, provides a means to predict the expected infrared spectral contrast differences between such soils (see preceding article).
The characteristics of InGaAs/GaAs modulation-doped photodetectors with two absorption bands

Abstract Modulation-doped photodetectors incorporated the low-temperature growth of GaAs and InGaAs as the absorption layers, respectively, are described. The photodetectors, which behave as a normal-off modulation-doped field effect transistor, have a low dark current of 16 nA at a bias of 5 V and can be turned on by illuminating light. A high responsivity of 19 A/W biased at 10 V is presented under a 0.8-μm light illumination and the spectral response exhibits two main stronger absorption peaks at 870 and 910 nm, which are the band-edge transitions of GaAs and InGaAs, respectively.