cssi/SciSciGPT-SciSciNet huggingface dataset:
Calcium and Phosphorus Requirements of Broilers as Influenced by Energy, Sex and Strain

Abstract THE 1960 National Research Council recommendation of 1.0 percent calcium and 0.6 percent total phosphorus for growing chickens has been challenged in recent years, more so with calcium than with phosphorus. Calcium requirements that have been proposed for normal growth are 0.5 percent (Simco and Stephenson, 1961); 0.6 percent (Pensack et al., 1959; White-Stevens et al., 1960; and Formica et al., 1962); 0.6 to 0.74 percent (Waldroup et al., 1962); 0.8 percent (Mehring, 1963); 0.99 and 1.07 percent (Edwards et al., 1963); and 1.0 percent from one day of age to 0.75 percent from 4 weeks through 8 weeks of age (Couch and Strother, 1963). Total phosphorus requirements that have been suggested for normal growth are 0.42 percent (Gardiner, 1962); 0.5 percent (Simco and Stephenson, 1961); 0.6 percent (Pensack et al., 1959; White-Stevens et al., 1960; and Formica et al., 1962); and 0.64 percent with normal Ca:P ratios and vitamin…
Adipocyte Versus Pituitary Leptin in the Regulation of Pituitary Hormones: Somatotropes Develop Normally in the Absence of Circulating Leptin

Leptin is a cytokine produced by white fat cells, skeletal muscle, the placenta, and the pituitary gland among other tissues. Best known for its role in regulating appetite and energy expenditure, leptin is produced largely by and in proportion to white fat cells. Leptin is also important to the maintenance and function of the GH cells of the pituitary. This was shown when the deletion of leptin receptors on somatotropes caused decreased numbers of GH cells, decreased circulating GH, and adult-onset obesity. To determine the source of leptin most vital to GH cells and other pituitary cell types, we compared two different leptin knockout models with Cre-lox technology. The global Lep-null model is like the ob/ob mouse, whereby only the entire exon 3 is deleted. The selective adipocyte-Lep-null model lacks adipocyte leptin but retains pituitary leptin, allowing us to investigate the pituitary as a potential source of circulating leptin. Male and female mice lacking adipocyte leptin (Adipocyte-lep-null) did not produce any detectable circulating leptin and were infertile, suggesting that the pituitary does not contribute to serum levels. In the presence of only pituitary leptin, however, these same mutants were able to maintain somatotrope numbers and GH mRNA levels. Serum GH trended low, but values were not significant. However, hypothalamic GHRH mRNA was significantly reduced in these animals. Other serum hormone and pituitary mRNA differences were observed, some of which varied from previous results reported in ob/ob animals. Whereas pituitary leptin is capable of maintaining somatotrope numbers and GH mRNA production, the decreased hypothalamic GHRH mRNA and low (but not significant) serum GH levels indicate an important role for adipocyte leptin in the regulation of GH secretion in the mouse. Thus, normal GH secretion may require the coordinated actions of both adipocyte and pituitary leptin.
CACREP's Relevance to Professionalism for School Counselor Educators

Archival data from 1994 to 2003 were used to examine the Council for Accreditation of Counseling and Related Educational Program's (CACREP) association with professionalism for school counselor educators. Indicators of professionalism included school counselor educators' contributions to the profession (i.e., journal publications and conference presentations), leadership in professional organizations, and pursuit of counseling credentials. Data analysis revealed weak (small effect sizes), yet statistically significant, relationships between CACREP accreditation and indicators of professionalism for school counselor educators.
β sheets not required: combined experimental and computational studies of self-assembly and gelation of the ester-containing analogue of an Fmoc-dipeptide hydrogelator.

In our work toward developing ester-containing self-assembling peptides as soft biomaterials, we have found that a fluorenylmethoxycarbonyl (Fmoc)-conjugated alanine-lactic acid (Ala-Lac) sequence self-assembles into nanostructures that gel in water. This process occurs despite Fmoc-Ala-Lac’s inability to interact with other Fmoc-Ala-Lac molecules via β-sheet-like amide–amide hydrogen bonding, a condition previously thought to be crucial to the self-assembly of Fmoc-conjugated peptides. Experimental comparisons of Fmoc-Ala-Lac to its self-assembling peptide sequence analogue Fmoc-Ala-Ala using a variety of microscopic, spectroscopic, and bulk characterization techniques demonstrate distinct features of the two systems and show that while angstrom-scale self-assembled structures are similar, their nanometer-scale size and morphological properties diverge and give rise to different bulk mechanical properties. Molecular dynamics simulations were performed to gain more insight into the differences between the...
Simulation and modeling of kinetics of silicon oxidation in the thin oxide regime

Thermal oxidation of Silicon in the thin regime is of vital importance to VLSI device engineers because thin layers of SiO2 are exclusively used as the gate dielectric for high performance of MOS devices. There exists a number of models to explain this kinetics of oxidation. However there is a considerable variance among the reported rate constants, which are supposed to describe the oxidation process. Rather than arriving at an alternative model, the present study aims at simulation of existing models of oxidation in dry oxygen, with a recent set of experimental data and arrive at the best possible model and provide accurate rate constants for oxidation in dry oxygen. These experimental data have been obtained, earlier, using high-resolution transmission electron microscopy (HRTEM) and ellip-sometry techniques to measure thicknesses of silicon oxide, grown at 800° in dry oxygen, in the thickness range of 2-20 nm.
Hemodynamic Effects of Glucagon in Patients Following Prosthetic Valve Replacement

The intravenous administration of 5.0 mg of glucagon to 16 digitalized patients on the first postoperative day after prosthetic valve replacement resulted in significant cardiac inotropic effects. Since glucagon is effective in the presence of catecholamine depletion or beta-adrenergic blockade and appears to have little arrhythmogenic potential, it would appear to be a useful agent for the treatment of myocardial depression occurring in association with open cardiac surgery.
CO and CO2 hydrogenation over metal oxides: a comparison of ZnO, TiO2 and ZrO2

Abstract Infrared spectroscopy and temperature-programmed techniques are used to examine and compare the interaction of CO/CO 2 /H 2 with three metal oxides, ZnO, TiO 2 and ZrO 2 . Common surface species are formed over these oxides at 1 atm pressure, and their reactive characteristics suggest that CO hydrogenation over these oxides occurs via a formate-methoxide mechanism. Differences among the oxides were observed in that TiO 2 did not hydrogenate CO or CO 2 into methanol.
Optical and EPR characterizations of oxygen-evolving Photosystem II subchloroplast fragments isolated from the thermophilic blue-green alga Phormidium laminosum☆

Abstract An oxygen-evolving, Photosystem II particle was isolated from the thermophilic, blue-green alga, Phormidium laminosum, according to the procedure of Stewart and Bendall (Stewart, A.C. and Bendall, D. (1979) FEBS Lett. 107, 308–312). Our particle has an oxygen-evolution activity of 1500–1600 μmol O2/mg chlorophyll per h. The oxygen-evolution activity has a pH optimum at 5–6, and is abolished at pH 9. Maximum oxygen evolution occurs at approx. 47°C in whole cells, but at 29°C in the particles. The activity decreases to 50% when the cells are heated for 30 min at 55°C; with the particles, 50% inactivation occurred at 47°C for the same heating time of 30 min. Flash excitation of the particle at 100 K produced absorbance changes whose difference spectrum in the ultraviolet-to-near infrared region shows photochemical charge separation and recombination of P-680+ and Q− in the dark with t 1 2 of 1.75 ms. An EPR spectrum for the P-680+ free radical, with g 2.0027 and ΔHpp = 8 G, was constructed from flash-induced EPR changes under conditions identical to those used for obtaining P-680 absorbance changes. The actinic light-induced variable fluorescence yield is 5-fold that induced by the weak probing beam alone. Addition of dithionite to the particle brings the fluorescence to the same maximum level. Under the reducing condition, strong actinic light caused the fluorescence to decrease. This observation is consistent with the notion that variable fluorescence yield in Photosystem II originates, as in green-plant chloroplasts, from recombination luminescence, the attenuation of which corresponds to photoaccumulation of reduced pheophytin under these conditions. Broad segments (300 nm) of the difference spectrum for pheophytin photoreduction were recorded by an intensified photodiode array in conjunction with a phosphoroscopic photometer. Kinetic spectrophotometric assays together with chemical analysis showed a rather clean and simple stoichiometry in these particles, namely, 1 P-680:1 Ph:1 Q:4 Mn:44 Chl. Initial investigation failed to reveal the doublet EPR spectrum previously observed for Ph−·Q− Fe in spinach subchloroplast particles (Klimov, V.V., Dolan, E. and Ke, B. (1980). FEBS Lett. 118, 97–100). A hyperfine EPR spectrum consisting of 16–20 lines and presumably associated with the manganese clusters in the oxygen-evolving protein has been confirmed in these particles. Tris washing but not washing with EDTA eliminates this signal. Active oxygen-evolving particles also yield the IIvf signal with a t 1 2 of approx. 800 μs. Upon Tris washing, the IIf signal appears which decays in 23.5 ms.
Time-integrating acousto-optic correlator for wideband random noise radar

A time-integrating acousto-optic correlator (TIAOC) is a good candidate for imaging and target detection using a wideband random noise radar system. We have developed such a correlator for a random noise radar with a signal frequency range of 1-2 GHz. This system has demonstrated good wideband signal correlation performance with good dynamic range and fine tuning of delays.
Clarifying the Butler–Volmer equation and related approximations for calculating activation losses in solid oxide fuel cell models

Abstract This paper shows the importance of including the activation losses in a model designed to accurately predict the voltage–current relationship of a modern solid oxide fuel cell. The governing equation for voltage drop due to activation losses, the Butler–Volmer equation, is discussed and the derivation and applicability of several approximations is investigated. Finally, the assumptions required to combine the separate anode and cathode activation loss calculations into a single-term equation are clarified.
The Burden of Visual Truth: The Role of Photojournalism in Mediating Reality

Contents: Preface. Introduction. The Vision Instinct. From Instinct to Practice. The Heart of the Seer. Stealing the Soul. Tending the Gate. Is Seeing Still Believing? Whose Truth? Toward an Ecology of the Visual. Translating the Visual. The Problem of Real People. The Future. Afterword.
Radiation-induced impulse on a spherical shell

Abstract Formulas for the membrane response of a thin, elastic, spherical shell to a radiation-induced impulse load are derived and some numerical results are presented.
Identification of novel glutathione conjugates of disulfiram and diethyldithiocarbamate in rat bile by liquid chromatography-tandem mass spectrometry. evidence for metabolic activation of disulfiram in vivo

Recent studies have shown that the inhibitory effects of disulfiram and diethyldithiocarbamate (DDTC) (to which disulfiram is rapidly reduced in vivo) on the liver mitochondrial low-Km form of aldehyde dehydrogenase (ALDH) may be mediated by a reactive metabolite(s) of these compounds. In order to investigate the nature of such electrophilic intermediates in vivo, the present study was carried out with the goal of detecting and identifying their respective glutathione (GSH) conjugates in the bile of rats dosed ip with either disulfiram (75 mg kg-1) or sodium DDTC (114 mg kg-1). By means of highly selective screening strategies based on coupled liquid chromatography-tandem mass spectrometry techniques, one major and four minor GSH adducts were identified as common biliary metabolites of disulfiram and DDTC. The major conjugate, whose excretion into bile over 4 h accounted for ca. 1% of the dose of either precursor, was identified as S-(N,N-diethylcarbamoyl)glutathione (SDEG). In vitro experiments with synthetic SDEG demonstrated that this carbamate thioester derivative is chemically stable in aqueous media under physiological conditions and does not carbamoylate nucleophiles such as cysteine. Consistent with these findings, SDEG failed to inhibit yeast ALDH in vitro. The minor GSH conjugates in bile were identified as S-(N,N-diethylthiocarbamoyl)glutathione, S-(N-ethyl-carbamoyl)glutathione, S-(N-ethylthiocarbamoyl)glutathione, and S-[N-(carboxymethyl)-N- ethylcarbamoyl]glutathione, the structures of which indicate that metabolic oxidation takes place at the thiono sulfur group and at each of the carbon atoms of disulfiram and DDTC.(ABSTRACT TRUNCATED AT 250 WORDS)
Outpatient treatment of deep venous thrombosis in diverse inner-city patients

Abstract Purpose: We sought to describe the development and outcomes of a hospital-based program designed to provide safe and effective outpatient treatment to a diverse group of patients with acute deep venous thrombosis. Methods: Patients enrolled in the program were usually discharged on the day of or the day after presentation. Low- molecular-weight heparin was administered for a minimum of 5 days and warfarin was given for a minimum of 3 months. The hospital provided low-molecular-weight heparin free of charge to patients. Patients received daily home nursing visits to monitor the prothrombin time, assess compliance, and detect complications. The inpatient and outpatient records of the first 89 consecutive patients enrolled in the program were reviewed. Patients were observed for a 3-month period after enrollment. Results: The median length of stay was 1 day. Low-molecular-weight heparin was administered for a mean (± standard deviation [SD]) of 4.7 ± 2.4 days at home. Recurrent thromboembolism was noted in 1 patient (1%), major bleeding in 2 patients (2%), and minor bleeding in 2 patients (2%). No patients died or developed thrombocytopenia. Assuming that patients would have been hospitalized for the duration of treatment with low-molecular-weight heparin, the program eliminated a mean of 4.7 days of hospitalization, with an estimated reduction of $1,645 in total health care costs per patient. Conclusion: This hospital-based program to provide outpatient treatment of deep venous thrombosis to a diverse group of inner-city patients achieved a low incidence of adverse events and substantial health care cost savings. Specific strategies, including providing low-molecular-weight heparin free of charge and daily home nursing visits, can be utilized to facilitate access to outpatient treatment and ensure high-quality care.
Infrared in automotive applications

As the automotive industry continues to develop advanced materials and manufacturing processes, infrared imaging has the potential to become a major tool in process monitoring and closed loop process control. This paper reviews five novel applications of infrared imaging in applications such as product testing, component manufacture, and vehicle assembly. Infrared was found to be effective as a diagnostics tool for characterizing disc brake systems and electronic engine control sensors. The effectiveness of infrared to qualify fuel nozzle backspray was used to optimize hardware design for fuel systems. Finally, infrared was found to be useful in vehicle assembly operations in the installation of windshield glass and instrument panel hardware where visual inspection was impractical. The speed of image capture and the availability of image processing software for real time image processing and closed loop process control will no doubt find more applications as infrared imaging finds its niche in the automotive industry.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Scintillation & Pulsar Timing: Low-level Timing Noise from the Kolmogorov Halo

Many systematic effects need to be removed in order to obtain the highest quality pulsar timing data. Interstellar propagation effects may be reduced by employing coherent dedispersion and observing at 1 GHz or above to avoid strong scattering. However, these techniques may not adequately bring propagation effects below the level of other systematic or random errors in the observation. We show that low-level scattering in a Kolmogorov halo produces time delays that are much larger than normally recognized and are time variable. These may be a significant source of noise in some high precision timing efforts.
Synthesis and photo-oxidative degradation of 2,6-bis-[ω-trimethylsiloxypolydimethylsiloxy-2′-dimethylsilylethyl]acetophenone

Abstract Dihydridocarbonyltris(triphenylphosphine)ruthenium (Ru) catalyzes the copolymerization of α,ω-divinylsiloxanes with aromatic ketones such as acetophenone to give polymers which have regularly alternating 2,6-diethylene-acetophenone and disiloxane units in the backbone. These copolymers absorb light in the UV λ max ∼280 nm , and are photochemically active. Monomeric model systems 2-(2′-trimethylsilylethyl)acetophenone (III), and 2-(3′,3′,5′,5′,5′-pentamethyl-3′,5′-disila-4′-oxaheptanyl)acetophenone (IV), as well as, 2,6-bis[ω-trimethylsiloxypolydimethylsiloxy-2′-dimethylsilylethyl]acetophenone (II) were prepared and their photochemistry in the presence and absence of oxygen studied. Photolysis of alt-copoly(2,6-diethylene-acetophenone/disiloxane) in the absence of oxygen results in recovered polymer whose molecular weight has not changed. On the other hand, photolysis in the presence of oxygen results in significant polymer degradation. Likewise, III was stable to irradiation in methanol-d4 solution in the absence of oxygen. Deuterium was specifically incorporated into the benzylic methylene groups of recovered III. The photolysis of III in the presence of oxygen yields hexamethyldisiloxane and 1,2-diacetylbenzene. Mechanisms that accounts for these results are proposed.
Genetic risks and diabetic complications—another ‘black hole’ in biology and medicine?

It is nowadays popular to speculate on the nature of the Universe, on galaxies and the significance of black holes. Much of what occurs in the universe still remains an enigma and is the subject of considerable controversy. New theories seem to be evolving, almost monthly. Unfortunately, our knowledge concerning the pathogenesis and progression of chronic diabetic complications seems to be in a similar state of controversy. One would think that with all the studies undertaken heretofore, we would have the answer as to the relative importance of close diabetic control and genetic susceptibility in the development of the chronic complications of diabetes. The polemic should not be ‘nature’ versus ‘nurture’ in the development of diabetic complications. It is evident that there is no distinct dichotomy between genetic and environmental factors in disease states. Rather, what probably exists is an interaction between the metabolic milieu and genetic determinants in the progression of chronic diabetic complications. Assuming that metabolic alterations such as hyperglycemia lead to the development of diabetic complications, then it is only logical and impera-
Grating Coupled Waveguide Biosensor Based on Porous Silicon

Porous silicon waveguides with integrated porous silicon grating couplers are demonstrated as small molecule biosensors. Two fabrication methods are presented for the grating couplers: standard electron beam lithography with reactive ion etching and a new technique based on direct imprinting of porous substrates. Although the gratings fabricated using standard lithographic techniques have steeper sidewalls and enable a larger available sensing surface area inside the waveguide, the imprinted gratings have the advantage of rapid and low-cost fabrication. Both the lithographically and imprinted sensors are shown to have waveguide losses on the order of 10 dB/cm, and both are demonstrated for detection of 16mer nucleic acids.
Attribution of attitude as a function of behavioral direction and freedom: Reactance in the eye of the observer

Abstract In a variation of the Festinger and Carlsmith dull-task paradigm an actor-stooge was given free-choice, forced-compliance choice, or no-choice as to whether he should tell the “waiting subject” that the task was dull or that the task was enjoyable. Crosscutting this three-level manipulation of behavioral freedom was a two-level manipulation of behavioral direction. The actor-stooge either chose or agreed to inform the “waiting subject” that the task was dull or that the task was enjoyable. In agreement with Jones and Davis' theory of correspondent inference observer-subjects made positively correspondent inferences in the free-choice condition, i.e., the actor-stooge was attributed with a more unfavorable attitude toward the task when he chose to advocate the dullness of the task than when he chose to advocate the enjoyableness of the task. However, within the no-choice condition, previously unobtained negative correspondent inference occurred. The actor-stooge was attributed with a more unfavorable attitude toward the task when he was required to advocate the enjoyableness of the task than when he was required to advocate the dullness of the task. These later results were interpreted as indicating that the observers attributed reactance to the actor-stooge in the condition in which the most social pressure was exerted. A second experiment demonstrated that the negative correspondence effect was not due to assumptions regarding other subjects' preference and also demonstrated the dependence of the effect on the absence of a rationale for the no-choice assignment of behavioral direction.
Current Zero Phenomena in an Orifice Type Gas Blast Interrupter

In an orifice type gas blast interrupter a rather "quiet" arc section of about 10 mm length close to the vena contracta was dominant during thermal recovery, both in air and in SF6. For small dI/dt values, the associated power loss was only 1000 watts for air and 600 watts for SF6, which is close to an estimated laminar loss of 400 watts for air.
Proton transfer in catalysis and the role of proton shuttles in carbonic anhydrase

The undisputed role of His64 in proton transfer during catalysis by carbonic anhydrases in the α class has raised questions concerning the details of its mechanism. The highly conserved residues Tyr7, Asn62, and Asn67 in the active-site cavity function to fine tune the properties of proton transfer by human carbonic anhydrase II (HCA II). For example, hydrophobic residues at these positions favor an inward orientation of His64 and a low pKa for its imidazole side chain. It appears that the predominant manner in which this fine tuning is achieved in rate constants for proton transfer is through the difference in pKa between His64 and the zinc-bound solvent molecule. Other properties of the active-site cavity, such as inward and outward conformers of His64, appear associated with the change in ΔpKa; however, there is no strong evidence to date that the inward and outward orientations of His64 are in themselves requirements for facile proton transfer in carbonic anhydrase.
Aiding in biodiversity and ecosystem science and policy interface gaps

Aiding in biodiversity and ecosystem science and policy interface gaps The final operational design of the Intergovernmental Platform on Biodiversity and Ecosystem Services ( IPBES), which addresses gaps in the science and policy interface on these issues, was agreed upon by representatives from 90 nations at a 23 April meeting in Panama City, Panama. Core functions of IPBES include performing regular assessments of knowledge on biodiversity and ecosystem services and their linkages and identifying and prioritizing key scientific information for policy makers. The IPBES secretariat will be based in Bonn, Germany, and a trust fund will be set up to receive voluntary contributions from governments and others. For more information, see http://www.ipbes.net.
A note on the recovery of inter-block information in balanced incomplete block designs

Consider the recovery of interblock information in balanced incomplete block designs. It is shown that the recovery of interblock information through the estimated generalized least squares (EGLS) estimator may improve the estimation, provided (b-t) > 4 where b =number of blocks and t =number of treatments. An expression for the variance covariance matrix for the EGLS estimator is provided and its behaviour is studied.
REINFORCING EFFECTS OF CAFFEINE IN COFFEE AND CAPSULES

In a residential research ward the reinforcing and subjective effects of caffeine were studied under double-blind conditions in volunteer subjects with histories of heavy coffee drinking. In Experiment 1, 6 subjects had 13 opportunities each day to self-administer either a caffeine (100 mg) or a placebo capsule for periods of 14 to 61 days. All subjects developed a clear preference for caffeine, with intake of caffeine becoming relatively stable after preference had been attained. Preference for caffeine was demonstrated whether or not preference testing was preceded by a period of 10 to 37 days of caffeine abstinence, suggesting that a recent history of heavy caffeine intake (tolerance/dependence) was not a necessary condition for caffeine to function as a reinforcer. In Experiment 2, 6 subjects had 10 opportunities each day to self-administer a cup of coffee or (on different days) a capsule, dependent upon completing a work requirement that progressively increased and then decreased over days. Each day, one of four conditions was studied: caffeinated coffee (100 mg/cup), decaffeinated coffee, caffeine capsules (100 mg/capsule), or placebo capsules. Caffeinated coffee maintained the most self-administration, significantly higher than decaffeinated coffee and placebo capsules but not different from caffeine capsules. Both decaffeinated coffee and caffeine capsules were significantly higher than placebo capsules but not different from each other. In both experiments, subject ratings of "linking" of coffee or capsules covaried with the self-administration measures. These experiments provide the clearest demonstrations to date of the reinforcing effects of caffeine in capsules and in coffee.
Determining scenic quality along highways: a cognitive approach

Abstract This paper describes a method for assessing scenic quality along existing roadsides in Connecticut (USA) based on a cognitive approach reflecting the complexity of human/landscape interaction. Landscape types (land use and land cover) which could be used in making spatially related land use and planning decisions were selected and photographed. A sample of representative scenes was rated for seven psychological predictors of theoretical interest. Thirty-six photographs representing nine landscape categories were shown to 249 people from three sample groups (highway residents, transportation planners, and the general public). Scenes were rated for preference on a five point scale, and mean preference ratings were calculated for individual images and landscape categories. The underlying patterns in preference ratings were examined by factor analysis which indicated four major dimensions of preference. The relationships among the landscape categories, the psychological predictors, and the dimensions derived by factor analysis are discussed. Results of this investigation indicate that preferences for roadside landscapes are determined both by pattern of land cover and land use and by psychological information. Differences in responses based on sample group or respondents' background are not discussed.
Variation of element fractionation as a function of pH for oxide, hydroxide and oxide—hydroxide solidsolution—aqueous-solution systems

Abstract The equations relating element fractionation and pH are derived for systems containing an oxide, hydroxide, or oxide—hydroxide solid solution in equilibrium with an aqueous solution. These expressions demonstrate that the fractionation coefficient for a two-component solid solution in equilibrium with an aqueous solution at any specified pH is equal to the ratio of the solubilities of the pure end-member components at that pH, assuming both solutions are ideal and only mono-hydroxo complexes form. For such a system containing a multi-component solid solution, the ratio of the partition coefficients for the individual components at any pH is inversely proportional to the solubilities of the pure components at that pH. The fractionation coefficient for a two-component solid solution and the ratio of partition coefficients for a multi-component solid solution will be unaffected by changes in pH within any interval in which the ratio of end-member solubilities remains constant. The ratio of two components will be identical in the solid and aqueous phases at any pH at which the end-member solubilities are equal. A reversal in the relative solubilities of two components as a result of a change in pH will produce a corresponding reversal in the component preferentially incorporated into the solid solution. Systems in which only the neutral and singly-charged complexes are present in significant concentrations produce simplified equations for the relationship of element fractionation to pH. Various pH intervals are recognized in which specific combinations of these complexes dominate and the corresponding curves for log of the fractionation coefficient vs. pH are determined. These intervals are also applicable to the ratio of the partition coefficients for any two components in a multi-component solid solution. The effect of pH on element fractionation in naturally-occurring solid solutions will be determined by the relationship between the pH range which may reasonably be expected in nature and the pH dependence of the system under consideration. Element fractionation will be pH-independent if the ratio of solubilities for the end-member components is constant throughout the pH range associated with natural systems, but will be pH-dependent if this ratio varies within those limits.
Alterations in β1‐ and β2‐Adrenergic Receptor Density in the Cerebellum of Aging Rats

The densities of beta 1 and beta 2-adrenergic receptors were determined in homogenates of cerebral cortex and cerebellum of rats between 3 and 14 mo of age. No change in either receptor population occurred in the cortex during this period. In the cerebellum, a 20--25% decrease in the density of beta 2 receptors and a 350% increase in the density of beta 1 receptors occurred. The increase in beta 1 receptors in the cerebellum may be the result of a decrease in the function of the noradrenergic projections from the locus coeruleus which synapse on cerebellar Purkinje cells.
Increased Nitric Oxide in Exhaled Gas Is an Early Marker of Hypovolemic States

Acute hemorrhage is associated with a variety of physiologic and metabolic alterations, including vascular hyporeactivity and endothelial cell dysfunction. The lung is a major target organ during hemorrhagic shock. The effect of acute hemorrhage on NO production in the lung is not well described. In the present study we examined the effect of acute hemorrhage on exhaled NO (NOe), and studied how changes in blood volume and flow affect NOe. Anesthetized and mechanically ventilated rabbits were used. The effect of acute hemorrhage by slow exsanguination on NOe was examined using chemiluminescence. Because hemorrhagic shock is associated with decreased pulmonary blood flow, we established an isolated lung preparation perfused with autologous blood (Hct = 17.4%) and studied the effect of pulmonary flow rate on NOe independent of metabolic changes. In order to separate the effect of flow from the effect of changes in blood volume, we examined the effect of flow in isolated lungs perfused with a blood-free albumin solution (PAS). In the isolated lung, ventilation was similar to that used in the intact animal, and temperature, pH, pCO 2 , and PO 2 were kept normal. Prior to exsanguination, baseline NOe in the intact animal was 24 ± 3 ppb. At 5, 10, 15, and 20 min after initiating the hemorrhage, NOe rose to 31 ± 3,51 ± 7,94 ± 10, and 154 ± 16 ppb, respectively (P < 0.05). During baseline conditions in the blood-perfused isolated lungs (200 ml/min), NOe was 35 ± 3 ppb. When flow was decreased to 70 and 0 ml/ min, NOe increased to 37 ± 3 and 56 ± 6 ppb, respectively (P < 0.001). During baseline conditions in the PAS-perfused lungs (70 ml/min), NOe was 94 ± 13 ppb and was unaffected by changes in flow. The perfusion pressure in the isolated lungs was in the normal range. Reduction in blood flow rate in the isolated lung was associated with less than twofold increase in NOe. This was attributed to reduction in red blood cell volume and not due to changes in blood flow rate. Reduction in flow in the intact animal during hemorrhage generated more than threefold increase in NOe, suggesting that neurohumoral mediators, in addition to changes in flow, play an important role in determining NOe in the intact condition. NOe began to rise immediately after exsanguination began, and therefore may be a useful early marker of acute hemorrhagic shock and hypovolemia. This information may be useful in the intensive care setting.
Do preoperative indicators predict the presence of common bile duct stones during laparoscopic cholecystectomy

Background Criteria have been suggested to help decide if an intraoperative cholangiogram (IOC) should be performed during laparoscopic cholecystectomy (LC). They are a clinical history of passing a common bile duct (CBD) stone, elevated serum amylase, elevated liver function tests, or ultrasound findings suggesting a CBD stone. What is the sensitivity and specificity of the above criteria when the presence or absence of CBD stones is already known by IOC? What is the probability that these criteria will predict a CBD stone or be normal if a stone is absent, ie, the positive predictive value (PPV) and negative predictive value (NPV)? Methods We reviewed 420 cases of elective LC done between May 1990 and December 1992. In our teaching hospital, IOC is routine and acted as the reference standard for the presence of CBD stones. All 420 films were reviewed as well as the results of any preoperative endoscopic retrograde cholangiopancreatography (ERCP) (30 were done). The following preoperative indicators of CBD stones were recorded: any clinical history of CBD stones; an elevated amylase, SGOT, alkaline phosphatase, or bilirubin level; and ultrasound findings. The sensitivity, specificity, PPV, and NPV were calculated. Results CBD stones were found in 12% of these elective LC cases. The sensitivity, specificity, PPV, and NPV, respectively, for each preoperative indicator were: a history suggestive of CBD stones (36%, 94%, 45%, and 91%), serum biochemistries as a group (43%, 86%, 30% and 91%), and ultrasound findings of CBD stones (22%, 92%, 28% and 89%). We compared any elevation versus >2× from the normal range of the serum indicators and did not improve their accuracy. Combination of the indicators increased sensitivity and NPV but lowered specificity and PPV. The best predictor of CBD stones was the history (45%) and this was in a hospital with a CBD stone prevalence rate of 12%. Conclusion There are no predictive tests that can sufficiently increase an observer's probability estimate of the presence or absence of CBD stones to allow for “selective” IOC decisions.
Structure of Georges Bank

Abstract About 1,600 km of continuous seismic (sparker) profiles were recorded in the area of Georges Bank during 1963 and 1964. Structural cross sections and a structural contour map were drawn from the recordings. These materials, supplemented by soundings and bottom samples, indicate that the bank is underlain by Cretaceous, Tertiary, and Pleistocene strata that dip gently seaward and steepen near the continental slope. Unconformities are present between each of these main stratigraphic sequences. The bank is clearly a northeasterly extension of the continental shelf that borders southern New England. It has the form of a cuesta that is bounded on its landward side by the Gulf of Maine, which was deeply eroded by glaciers and possibly by preglacial streams.
Forty dot/millimeter resistive ribbon thermal print head

A key element to printing high resolution grey level images using resistive ribbon thermal printing technology, is the ability to fabricate a high density electrode print head. To print at 40 dots/mm resolution, the print head electrodes have to be on 25 im centers. Each electrode having a width of 15 to 17 /im. Wet etching techniques can not etch such structures in 25 thick tungsten. A reactive ion etching process suitable for manufacturing high resolution print heads from a tungsten sheet has been developed. Various system parameters were studied, such as gas mixtures, system vacuum pressure and applied RF power, with the goal of achieving an optimum etching process. The results identified SF6 based gas mixtures as the most suitable candidate for high volume removal of tungsten with an acceptable etch rate and edge profile. To study the print quality at 40 pel/mm, other parameters such as ink ribbon and paper surface finish were also investigated. An ink layer thickness and a paper were selected to match the quality of the high resolution print head. The electric power requirements to print single pel features repeatedly was studied.
When to introduce objects in teaching Java

With the move from procedural to object oriented programming (OOP), the number of concepts and programming techniques have widened, but the time allotted to teach an introduction to programming course is still the same. In this paper, we discuss the strategies to merge the OOP concepts with algorithms. We propose a balanced approach in which we start with objects from the very beginning and emphasize problem solving techniques and design throughout the course. This paper lays out a possible order of topics and the methodology to teach Java programming in the object oriented way. In addition, we discuss integrated environments in which Java can be taught, such as BlueJ, DrJava, and JBuilder.
An examination of the affect of the epoxide stereochemistry in the nitrogen extrusion from exo- and endo-6,7-diazo-3-oxotricyclo[3.2.2.02,4]Non-6-ene

Abstract The exo and endo isomers of 6,7-diazo-3-oxotricyclo[3.2.2.02,4]non-6-ene have been prepared and their extrusion of nitrogen examined. The exo isomer 10 underwent the expected homo-retro-Diels-Alder reaction at room temperature to give 4,5-dihydrooxepin (11), but the endo isomer extruded nitrogen at >180 °C to give cyclohexenone.
Comparison of the four anhydrous polymorphs of carbamazepine and the crystal structure of form I.

For decades, carbamazepine (CBZ) has served as a model compound for groupsengagedinthestudyofcrystalpolymorphism.Despiteconsiderableeffort,crystal structures for only three of its four anhydrous forms have previously been determined. Herein, we report the first single crystal X-ray structure of the high temperature modi- ficationofCBZ(formI).FormIcrystallizesinatricliniccell(P-1)havingfourinequivalent molecules with the following lattice parameters: a ¼5.1705(6), b ¼20.574(2), c ¼ 22.245(2) A ˚ , a ¼84.12(4), b ¼88.01(4), and g ¼85.19(4)8. Furthermore, we compare the physical properties of the four anhydrous polymorphs of CBZ, including the first comprehensivecharacterizationofformIV.Substantialdifferencesareseenamongthese forms by powder X-ray diffraction, infrared spectroscopy, thermomicroscopy, and differential scanning calorimetry. These data are correlated to their respective crystal structures for the first time. We have found that all polymorphs possess identical strong hydrogen bonding patterns, similar molecular conformations, and stabilities that are within 0.7 kcal/mol of each other. 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:2260-2271, 2003
Myxofibrosarcoma Initially Presenting as a Pleomorphic Hyalinizing Angiectatic Tumor (PHAT): is PHAT a Precursor or Unique Type of Myxofibrosarcoma?

Myxofibrosarcoma (MFS) is a common soft tissue sarcoma of adults. We present an unusual case which initially showed features of a pleomorphic hyalinizing angiectatic tumor (PHAT). The lesion was characterized by abundant plump, eosinophilic cells exhibiting striking nuclear atypia, set in a dense, hyalinized stroma with a prominent, angiectatic vasculature. Rare mitotic figures were identified. These findings were felt to be most consistent with the diagnosis of PHAT. Four months after removal, local recurrence was noted, which demonstrated findings of a high grade MFS, including a cellular proliferation of pleomorphic spindle cells set in a prominent myxoid stroma. Multiple mitoses, including atypical ones, were present. In light of these findings, the original specimen was reexamined and the diagnosis was revised to high- grade MFS. MFS, especially low-grade lesions, may be confused with several benign lesions. Previous cases mimicking PHAT have not been reported. We describe a unique case of high-grade MFS which initially showed characteristic features of a PHAT, raising the possibility that MFS may occasionally arise in, or have areas that masquerade as, PHAT. It is possible that PHAT, currently considered a benign neoplasm, may actually represent a peculiar form of MFS of low malignant potential.
Management Style and Environmental Scanning in the Search for Business Opportunities and Challenges

Managers that scan the environment in their boundary spanning roles need to be attentive to the opportunities and challenges that may arise due to changes occurring within the environment. As an industry environment changes, an entrepreneurial management orientation helps firms adapt to changing market conditions. The purpose of this study is to examine the link between management style and environmental scanning. Based on responses from 201 top-level hotel executives, the findings suggest that entrepreneurial managers are more frequent scanners of the environment.
An object-based model for dependable real-time distributed systems

A systematic way to introduce fault-tolerant and time-dependent properties into a complex software system is presented. The approach is based on an extended Petri net model, called the G-Net, enhanced with a deterministic timing scheme. In the timed G-Net (TGN) model, exception handling and time-out mechanisms are used to introduce the fault-tolerant and real-time properties. The basic idea is to avoid the timing error propagation from a faulty object to an object that interacts with it via a time-out mechanism, and also to allow an object to treat a timing error by raising an exception and triggering some corrective actions. Using TGNs as the basic building blocks, we further refine the model into the 'smart object' (SMO) model. In each SMO, an object can associated with a knowledge structure, which enables the object to dynamically change its behavior to react to changes in the environment. We use examples to show that a simplified real-time distributed air traffic control system can be modeled effectively using the SMO model.
Palliative Care: A Lifeline to Quality of Life

ASCO's Provisional Clinical Opinion offers the opportunity to bring clinicians a significant step forward in delivering truly patient-centered, family-focused care that can make a difference.
Assessment of herd management on organic and conventional dairy farms in the United States

The objective of this study was to evaluate management characteristics on organic and similarly sized conventional dairy farms located in New York, Wisconsin, and Oregon. Data from 192 organic farms (ORG), 64 conventional nongrazing farms (CON-NG), and 36 conventional grazing farms (CON-GR) were collected during farm visits and were size-matched and analyzed. The average lactation number of animals on ORG and CON-GR farms was 2.6 lactations, which was greater than that on CON-NG farms (2.3 lactations). A greater percentage of first-lactation heifers were found on conventional farms than on ORG farms. Facilities used by adult animals, including housing and milking facilities, did not differ among the grazing systems. Cattle on conventional farms were fed approximately twice as much grain as cattle on ORG farms and had greater milk production. Little difference was found for the average reported somatic cell count and standard plate count, suggesting that milk quality is not dependent on grazing system. Milking procedures were similar across all 3 grazing systems, indicating that an industry standard now exists for milking and that milk quality problems will need to be addressed with other management problems in mind. Although some disease prevention measures were commonly utilized on ORG farms, such as keeping a closed herd and having a written record of treatments administered to the animals, the use of outside support and vaccinations were found to be less prevalent on organic farms than on conventional farms.
Wavelength switching and routing using absorption and resonance

A resonator side coupled to a pair of waveguides can switch an optical signal between two ports by means of absorption. The absorptive mechanism is used to suppress the resonant power transfer, rather than to promote loss. Thus, the input signal only suffers small attenuation, provided that the mode volumes of the resonators can be made small enough. Multiply-coupled resonators lead to improved crosstalk performance for both the ON and OFF switched states. The performance of such devices are analyzed analytically, and universal switching curves are derived.
Characterization of recombinant CYP2C11: a vitamin D 25-hydroxylase and 24-hydroxylase

Studies were performed to further characterize the male-specific hepatic recombinant microsomal vitamin D 25-hydroxlase CYP2C11, expressed in baculovirus-infected insect cells, and determine whethe...
Strengthening Qualitative Studies and Reports

This article examines six criteria for conducting qualitative research and evaluating qualitative research reports in social work: (1) identification of the chosen philosophy/epistemology, (2) identification of audience and objectives, (3) specification of the study method, (4) identification of biases, (5) maintenance of social work ethics, and (6) assurance of consistency between conclusions and study philosophy, objectives, and presented data. Throughout, the author emphasizes the need to examine potentially disconfirming data in all qualitative research. These criteria are intended to guide qualitative researchers, inform the teaching of qualitative research methods, and aid review of qualitative research reports.
Tertiary history of C4 biomass in the Great Plains, USA

We use the carbon isotope composition of paleosols to reconstruct the history of C4 biomass on the Great Plains from ca. 23 to 1 Ma. The proportion of C4 biomass was uniform and moderate (12%‐34%) throughout the Miocene, increased between 6.4 and 4.0 Ma, and reached modern levels by 2.5 Ma. Ecological changes in Great Plains ungulates preceded the increase in C4 biomass. The contrasts in the paleosol and ungulate records may indicate initial development of C3 grasslands after the middle Miocene or a greater role for ecological interactions within communities in structuring ungulate faunas. Contrasts in paleosol records from different continents point to regional rather than global controls on the evolution of C4 grasslands.