cssi/SciSciGPT-SciSciNet huggingface dataset:
Bioaccumulation of selenium in birds at Kesterson Reservoir, California

This study was conducted to determine selenium (Se) concentrations in tissues of birds collected during the 1983–1985 nesting seasons at Kesterson Reservoir (an area receiving high-Se irrigation drainage water), compare them with birds from reference sites within California's Central Valley, and relate them to food-chain Se concentrations at the study sites. Within years, Se in livers of adult birds collected early and late in the nesting season changed significantly at both Kesterson and the primary reference site (Volta Wildlife Area). These changes were related to the length of time birds had been present at the study sites and the associated accumulation (at Kesterson) or depuration (at Volta) of Se. All species showed significant location differences, which were greatest in species that occurred at Kesterson throughout the year or fed more consistently within the reservoir. There were few species differences in Se for birds at the reference sites (where food-chain Se levels were “normal” [⩽2 μg/g, dry wt]). At Kesterson (where bird foods generally contained >50 μg Se/g), species patterns varied by year, probably because of varying periods of residence and other factors. Se concentrations in kidneys and livers of American coots (Fulica americana) were significantly correlated (r=0.9845); Se concentrations in breast muscles and livers of juvenile ducks (Anas spp.) also were correlated (r=0.8280). Body weights of adult coots were negatively correlated with liver Se concentration. Lateseason resident breeding birds or pre-fledging juvenile birds reared at a site usually provided the best indication of sitespecific Se bioaccumulation.
Quantification of Free-Carrier Absorption in Silicon Nanocrystals with an Optical Microcavity

We present a highly sensitive and accurate microcavity-based technique to quantify the free-carrier absorption (FCA) cross-section of semiconductor quantum-dot ensembles. The procedure is based on measuring the pump-intensity-dependent broadening of the whispering gallery modes (WGMs) of microdisk resonators. We have applied this technique to determine the FCA cross-section of Si nanocrystals (Si-ncs) in the visible−near-infrared wavelength range. Our procedure accounts for the size distribution effects by including the measured wavelength dependence of the excitation cross-section and the decay rate of photoexcited carriers in the analysis. By monitoring the WGM widths at various wavelengths in the 700−900 nm wavelength range, we found that the FCA cross-section follows an approximately quadratic wavelength dependence. The magnitude of the FCA cross-section of Si nanocrystals was determined to be a factor of 7 higher than that in bulk Si. For this reason, these findings have important implications for th...
Directed metabolic flow with high butanol yield and selectivity in continuous cultures ofClostridium acetobutylicum

This work addresses the problem of stable butanol formation byClostridium acetobutylicum in continuous culture. Sustained altered electron flow was observed in the presence of benzyl viologen which serves to redirect carbon flow towards primarily butanol formation. A yield of butanol of over 0.28 g.g−1 glucose was obtained and butanol comprised over 90% of the total solvents formed. Additionally, acid formation decreased significantly with butyric acid as the dominant acid end product.
Comparison of the In Vitro Hemodynamic Performance of New Flow Diverters for Bypass of Brain Aneurysms

One possible treatment for cerebral aneurysms is a porous tubular structure, similar to a stent, called a flow diverter. A flow diverter can be placed across the neck of a cerebral aneurysm to induce the cessation of flow and initiate the formation of an intra-aneurysmal thrombus. This excludes the aneurysm from the parent artery and returns the flow of blood to normal. Previous flow diverting devices have been analyzed to determine optimal characteristics, such as braiding angle and wire diameter. From this information, a new optimized device was designed to achieve equivalent hemodynamic performance to the previous best device, but with better longitudinal flexibility to preserve physiological arterial configuration. The new device was tested in vitro in an elastomeric replica of the rabbit elastase induced aneurysm model and is now in the process of being tested in vivo. Particle image velocimetry was utilized to determine the velocity field in the plane of symmetry of the model under pulsatile flow conditions. Device hemodynamic performance indices such as the hydrodynamic circulation were evaluated from the velocity fields. Comparison of these indices with the previous best device and a control shows that the significant design changes of the device did not change its hemodynamic attributes (p > 0.05).
On the origins of New World paleopathology.

Many of the lesions found in American Indian bones do not resemble those found in human bones from the Old World, suggesting that the American Indians suffered from a distinct group of illnesses. If Old World pathogens did not follow man to the New World, what were the sources of pre-Columbian Indian diseases? As in the Old World, humans were susceptible to diseases endemic in the local animal populations. Exposure to these diseases varied with culturally conditioned animal contacts. As the New World population increased, the probability for disease increased, to the point where it is likely that even in pre-Columbian times, disease rather than war or climatic changes may have been a major influence in changing settlement patterns. The generalization that the only Old World plants and animals found in the New were those brought by man seems to hold as true for the pre-Columbian disease organisms as it is for larger forms of life.
Interrelations between random walks on diagrams (graphs) with and without cycles.

Abstract Three topics are discussed. A discrete-state, continuous-time random walk with one or more absorption states can be studied by a presumably new method: some mean properties, including the mean time to absorption, can be found from a modified diagram (graph) in which each absorption state is replaced by a one-way cycle back to the starting state. The second problem is a random walk on a diagram (graph) with cycles. The walk terminates on completion of the first cycle. This walk can be replaced by an equivalent walk on a modified diagram with absorption. This absorption diagram can in turn be replaced by another modified diagram with one-way cycles back to the starting state, just as in the first problem. The third problem, important in biophysics, relates to a long-time continuous walk on a diagram with cycles. This diagram can be transformed (in two steps) to a modified, more-detailed, diagram with one-way cycles only. Thus, the one-way cycle fluxes of the original diagram can be found from the state probabilities of the modified diagram. These probabilities can themselves be obtained by simple matrix inversion (the probabilities are determined by linear algebraic steady-state equations). Thus, a simple method is now available to find one-way cycle fluxes exactly (previously Monte Carlo simulation was required to find these fluxes, with attendant fluctuations, for diagrams of any complexity). An incidental benefit of the above procedure is that it provides a simple proof of the one-way cycle flux relation Jn +/- = IIn +/- sigma n/sigma, where n is any cycle of the original diagram.
Functional Conducting Polymers via Thiol-ene Chemistry

We demonstrate here that thiol-ene chemistry can be used to provide side-chain functionalized monomers based on 3,4-propylenedioxythiophene (ProDOT) containing ionic, neutral, hydrophobic, and hydrophilic side chains. All reactions gave high yields and purification could generally be accomplished through precipitation. These monomers were polymerized either chemically or electro-chemically to give soluble materials or conductive films, respectively. This strategy provides for facile tuning of the solubility, film surface chemistry, and film morphology of this class of conducting polymers.
Characterization of Ca2+-Channels Responsible for K+-Evoked [3H]Noradrenaline Release from Rat Brain Cortex Synaptosomes and Their Response to Amyotrophic Lateral Sclerosis IgGs

The contribution of the different Ca 2+ -channel subtypes to the K + -evoked [ 3 H]noradrenaline release from rat cerebral cortex synaptosomes has been investigated. In the same experimental model, it was also verified whether the calcium-mediated neurotransmitter release is influenced by IgGs purified from sera of seven patients affected by sporadic amyotrophic lateral sclerosis. Synaptosome treatment with 3.0 μM nifedipine or 2.0 μM calciseptine, which block L-type channels, slightly decreased [ 3 H]noradrenaline release, the reduction being 7 and 13% of the control values, respectively. The blockade of N-type Ca 2+ -channels with ω-conotoxin-GVIA (0.001-1.0 μM) induced a concentration-dependent reduction of the neurotransmitter release, with maximum effect of 34%. ω-Agatoxin-IVA failed to significantly affect the studied release, which was instead markedly reduced by ω-conotoxin-MVIIC. After the blockade of N-type channels with maximal concentrations of ω-conotoxin-GVIA, 3.0 μM ω-conotoxin-MVIIC reduced the release by 58%. Synaptosome treatment with amyotrophic lateral sclerosis IgGs enhanced the K + -evoked [ 3 H]noradrenaline release, which was mostly mediated by P/Q- and N-type Ca 2+ -channels. The increase induced by pathologic IgGs (0.2 mg/ml) ranged from 11 to 62% for the different patients, and it was concentration-dependent. The basal release was instead unaffected by IgG treatment. The results of the present study suggest that the K + -evoked [ 3 H]noradrenaline release from brain cortex synaptosomes is mainly mediated by activation of P/Q- and N-type Ca 2+ -channels. Autoantibodies present in the sera of patients affected by sporadic amyotrophic lateral sclerosis may interact with these channels by producing an increased calcium influx, with consequent enhancement of the neurotransmitter release. Preliminary results of the present study have been published in abstract form (Martire et al., 1997, Pharmacol. Res. 35:9).
The legal regime governing seafloor polymetallic sulfide deposits

Abstract Beginning in 1977, oceanographers discovered seafloor vents spewing hot water into the surrounding water and sustaining exotic communities of marine life. They determined that the hydrothermal vent systems also produced deposits containing minerals of economic and strategic interest, thus sparking the interest of legislators and diplomats seeking the successful conclusion of the United Nations Conference on the Law of the Sea. This article examines the legal and regulatory regime which may govern development of these deposits off United States coastal waters, then turns to a discussion of how negotiators at the Law of the Sea Conference sought to incorporate the new sulfide discoveries into their efforts at international lawmaking.
Transport properties determinations of the one-dimensional, half-filled band Holstein-Frölich modified Hubbard model

Abstract The magnetic susceptibility, electrical conductivity, and specific heat of the Holstein-Frohlich modified Hubbard model are obtained with the restriction that the chemical potential μ be identically equal to one-half the intra-atomic electronic Coulomb repulsion U . Contributions to the conductivity for all driving frequencies ω are obtained. The specific heat calculation yields electron-phonon interaction corrections, but the susceptibility results are the same as those for the insulator limit Hubbard model.
Chemopreventive potential of Epoxy clerodane diterpene from Tinospora cordifolia against diethylnitrosamine-induced hepatocellular carcinoma

Medicinal plants are a promising source for identification of lead molecules for cancer therapy. In our continuous search to discover bioactive compounds from natural products, we isolated (5R, 10R)-4R, 8R-dihydroxy-2S, 3R:15, 16-diepoxycleroda-13(16), 17, 12S:18,1S-dilactone (ECD), a diterpenoid from Tinospora cordifolia and studied its chemopreventive potential in diethylnitrosamine (DEN) induced hepatocellular carcinoma (HCC) rats. Fifty male Wistar rats were divided into five groups. Group I served as normal control. Group II-IV were given DEN (0.01% in drinking water) for twenty weeks. In addition, Group III (preventive treatment) received ECD (10 mg/kg body weight) throughout the study. Group IV (curative treatment) received ECD (10 mg/kg body weight) for the last 8 weeks. Group V received ECD alone (10 mg/kg body weight) throughout the experimental period. At the end of the experimental period all the animals were sacrificed and analyzed for biochemical end points to assess the effect of ECD treatment in DEN induced HCC. The animals treated with DEN showed a decrease in the activities of antioxidant (SOD, CAT) and detoxification enzymes (GSH, GPx) with increase in the activities of the hepatic markers (SGOT, SGPT, LDH). Treatment of ECD in both preventive and curative DEN induced animals increased the level of antioxidants and detoxification enzymes, and decreased serum transaminase level and hepatic marker enzymes to near normal. Histopathological and nodular incidence also confirmed that ECD remarkably reduced tumor incidence and reversed damaged hepatocytes to normal. Our findings confirm that ECD exhibits preventive effect against chemically induced HCC in rats. ECD can be a potent chemopreventive drug for HCC.
Groundwater flow and implications for groundwater contamination north of Prewitt, New Mexico, U.S.A.

Abstract In the southern San Juan Basin, New Mexico, strata of Permian and younger age dip gently toward the center of the basin. Most previous investigators believed that recharge to these strata occurred by precipitation on the outcrops and groundwater flowed downdip to the north and northeast. Recent water-level measurements in an undeveloped part of the basin near Prewitt, New Mexico, show that groundwater at shallow depths in alluvium and bedrock flows southward, opposite to the dip direction, and toward a major ephemeral drainage in a strike valley. North of this area, groundwater in deep bedrock aquifers does appear to flow northward. This information suggests that there are two groundwater circulation patterns; a shallow one controlled by topography and a deeper one controlled by geologic structure. Significant amounts of recharge to sandstone aquifers by infiltration through outcrops is unlikely due to the near-vertical exposures on cliffs, the gentle dip of the strata, and small annual precipitation. Numerical model results suggest that recharge to bedrock aquifers may be from downward leakage via aquitards over large areas and leakage from narrow alluvial aquifers in the subcrop area. The recharge mechanism is controlled by the hydraulic conductivity of the strata. As the flow path is controlled by hydraulic conductivity contrasts, geologic structure, and topography, contamination movement from surface impoundments is likely to be difficult to predict without a thorough hydrogeological site investigation.
Inverse Relationship of Glucose-6-Phosphate Levels and Glucose Utilization in 6C3HED Lymphoma

Inverse Relationship of Glucose-6-Phosphate Levels and Glucose Utilization in 6C3HED Lymphoma
Particle geodesics and spectra in the spacetime tangent bundle

Abstract A limiting curvature of worldlines in spacetime serves as a possible basis for the differential geometry of the tangent bundle of spacetime. I first review briefly the resulting differential geometric structure of the spacetime tangent bundle. Next, I examine the relations between bundle geodesies and their projections on the spacetime base manifold. Possible classical particle equations of motion result from geodesic motion in the bundle manifold. Additionally, the Laplace-Beltrami operator is constructed on the bundle manifold. Possible particle spectra are represented by quantum fields that have a null eigenvalue when acted upon by the Laplace-Beltrami operator of the bundle manifold. The fields are shown to be automatically regularized by the limiting curvature of worldlines in spacetime, and particle spectra are shown to be cut off at very high energy.
Diagnostics of an artificial relativistic electron beam interacting with the atmosphere

We use a Monte Carlo model to simulate the interaction of a beam of relativistic (0.5-10 MeV) electrons with the upper atmosphere as they are injected downward from a notional high-altitude (thermospheric/ionospheric) injection platform. The beam parameters, defined by realistic parameters of a compact linear accelerator, are used to create a distribution of thousands of electrons. Each electron is injected downward from 300 km altitude toward the dense atmosphere, where it undergoes elastic and inelastic collisions, leading to secondary ionization, optical emissions, and X-rays via bremsstrahlung. In this report we describe the model initialization (i.e., development of the electron distribution), essential features of the Monte Carlo model, and secondary outputs, including optical emissions, X-ray fluxes, secondary ionization, and backscattered energetic electron fluxes. Optical emissions are propagated to the ground through the lower atmosphere, including the effects of atmospheric absorption and scattering, to estimate the brightness of the emission column for a given beam current and energy. Similarly, X-ray fluxes are propagated to hypothetical detectors on balloons and satellites. Secondary ionization is used to estimate the radar signal returns from various ground-based radar facilities. Finally, simulated backscattered electron fluxes are measured at the injection location. The simulation results show that each of these diagnostics should be readily detectable by appropriate instruments.
Moving Away from Ones and Zeros, Designing a Ground Data System Based on Higher Levels of Abstraction

Previous JPL ground systems have been designed with the Ground Data System (GDS) engineer in mind. The focus on these systems has been on packaging and delivery of low level information (frames, packets, telemetry values) to the end user. It was not that long ago when project teams would be huddled over a workstation, examining crude displays of telemetry bits organized in various ways, trying to determine the status of a spacecraft. Understanding the data often required additional levels of GDS expertise, or worse, transformation of the raw data into alternative formats followed by ingestion into other tools so that the data became meaningful. The primary focus was often to answer these types of questions: "Why did this particular frame fail Reed-Solomon decode? Why did this packet get marked as invalid? Why am I missing a block of telemetry from my query?" -- which are completely valid questions to ask from a GDS Engineer's point of view, and large families of tools have been designed to help answer these questions. But these are not the questions that most users care about - which are more like: "Why is the battery state of charge trending down? Show me a summary image report for the last traverse to the target. Show me a data accountability summary for the last DSN pass." Answers to these questions, which are what users are looking for, requires a higher level of abstraction and supporting tools than mining through ones and zeros. JPL has created a next generation capability called the Mission Data Processing and Control System (MPCS) which is designed to support this higher level of abstraction by providing customizable views of the ground system combining collections of lower level information into more meaningful ways. Instead of examining frames, packets, and individual telemetry data points -- MPCS is capable of providing comprehensive summary reports, product status, overall flight/ground event status, as well as payload health summaries. Based on these higher level views, end users can make tactical or strategic decisions, or drop into detailed analysis as needed. System designers need to continue building systems that support low level GDS troubleshooting - but the basic design of a GDS should be geared towards what end users actually need to see. This paper will describe the capabilities of MPCS that directly support these higher levels of abstraction, and which are being used today in missions such as the Mars Science Laboratory and other NASA missions.
The False Dichotomy of Morality and Self-Interest as Determinants of Action: Facilitating Intervention against Genocide

Under the contingencies operating in the current political climate, appeals to aid other nations are often made from two positions that are cast as opposing determinants of action. The first involves an appeal to the moral values of an intervening nation that supports human rights and social justice while the second involves an appeal to national interest in that action is only taken if it benefits the intervening nation. In the behavior analytic system, moral values are not viewed as causal entities, and as a result the behavior analytic standpoint dissolves the dichotomy that casts acting out of self-interest and acting out of altruistic morality as opposites. The resulting re-conceptualization focuses on the consequences of action, allowing for better accuracy in predicting the conditions under which nations are likely to act in the aid of others while providing a more effective vehicle for promoting human rights worldwide.
Microemulsion polymerization within near- and supercritical continuous phases: Effect of microemulsion structure on reaction characteristics

Abstract The inverse microemulsion polymerization of acrylamide within near-critical and supercritical alkane continuos phases was studied using high pressure dynamic light scattering. Results shwo that the structure of the precursor microemulsion, formed from ethoxylated alcohol surfactants, is a strong function of the density of the continuous phase. Increasing the density apparently decreases the strength of micelle-micelle attractions, and thus the tendency for the micelles to cluster. Decreased clustering tends to decrease the molecular weight or polyacrylamide produced within the micelles, but at the same time increases the rate of the reaction significantly. As in the microemulsion polymerization of acrylamide within conventional liquid continuous phases, dynamic light scattering revealed a gradual decrease in the apparent micelle size as the reaction proceeds. Further, molecular weight is only weakly dependent on the initiator concentration, possibly due to high chain transfer reaction rates for solvent, monomer, and/or surfactant.
Expanding the Repertoire of Chalcogenide Nanocrystal Networks: Ag2Se Gels and Aerogels by Cation Exchange Reactions

Cation exchange is shown to be a simple and efficient method to prepare nanostructured Ag(2)Se gels and aerogels from CdSe gel precursors. Treatment of CdSe wet gels with AgNO(3) yields, for the first time, Ag(2)Se gels, and these are transformed to high surface area, nanostructured aerogels by supercritical fluid drying. The striking similarity in crystallite size, morphology, and surface area characteristics between CdSe and the corresponding Ag(2)Se aerogels supports a mechanism in which the bonding within the gel network remains globally unchanged, even as the structural attributes of the primary particle components are undergoing a dramatic transformation (hexagonal CdSe to cubic Ag(2)Se). Intriguingly, the rapid exchange also enables exquisite control of composition on the macroscale; reduced concentrations of Ag(+) lead to two-component (i.e., CdSe inside, Ag(2)Se outside) heterogeneous structures of mm-cm dimensions. Overall, this methodology offers a simple approach for the generation of porous nanocrystalline metal chalcogenide networks of known or new compositions.
The limitation of growth of Trypanosoma musculi in vitro.

Abstract Trypanosoma musculi grow readily in vitro provided their growth is supported by mammalian cells. In the presence of murine spleen cells, or spleen cell-conditioned medium, the parasites increase by 100-fold, or more, in a period of 5–6 days. Growth ceases abruptly and death of the parasites soon follows. The reason for the termination of growth has been obscure and is the subject of this report. Termination of growth is not due to an immunological process; not even of ablastin affecting epimastigote reproduction. Instead it appears that other growth inhibitory substances are responsible. Culture medium, collected from spent cultures on day 8 after initiation, inhibits T. musculi growth in fresh medium in dose-dependent fashion. No inhibitory substances were present in medium collected earlier, during the phase of rapid parasite growth. These inhibitory substances appeared to be derived from the parasites rather than the cocultivated spleen cells.
Temporally-related stimulus properties of delta9-tetrahydrocannabinol in monkeys.

A two-choice operant discrimination procedure was used to train three monkeys to respond differentially between a fixed dose of δ9-tetrahydrocannabinol (δ9-THC) and the drug vehicle alone. During the acquisition of the drug discrimination, both drug and vehicle alone were administered orally 2.5 h prior to the experimental session. The drug-stimulus time course was than tested by administering either the same dose of δ9-THC or the vehicle alone from 0.5 to 16.5 h before the session. Varying administration time had no effect on the established discrimination during vehicle alone test sessions. However, orderly time-related generalization gradients were obtained around the drug administration time used during discrimination training.
Regional Integration of Nineteenth Century U.S. Egg Markets

Multivariate asymmetric threshold vector error correction models are applied to a historical analysis of the regional integration of U.S. markets for eggs at the turn of the nineteenth century. Two general approaches to the selection of the thresholds are considered. The first criterion ignores the cross equation correlation while the latter explicitly accounts for it. Our results suggest that threshold behaviour characterises spatial price linkages between the markets analysed.
Burkeian and Freudian theories of identification

Kenneth Burke's encounters with Freudian theories of identification have for the most part been productive for rhetorical critics. Burke transformed two Freudian processes of identification—the perception of similarity in the production of hysterical symptoms and one process of representation in dreams—into processes which partake of the “forensic texture”; of society. However, movement and interpretive organizational critics have been hampered by Burke's submersion of important distinctions in Freud's treatment of identification in groups. By overlooking the relationship between Burkeian and Freudian theory, movement and organizational critics have compromised their ability to offer satisfying explanations for the success or failure of organizational discourse as a group phenomenon.
Describing the Virgin

Descriptions of the Virgin began to emerge in Italian popular devotional literature in the fifteenth century and in theological texts in the sixteenth century. In such texts, worshippers and readers were no longer left to imagine the appearance of the Virgin in prayer. Rather, her image was given in a description. And this represents a complete shift away from the tradition in the West, a tradition that originated in St Augustine's De Trinitate. This tendency to describe the physical appearance of the Virgin for meditation via texts also existed, although inconsistently, in paintings of her. In the itinerant artist Antonello da Messina’s two images of the Annunziata (Munich and Palermo, c.1470) the painter appropriates the pictorial structure of portraiture to depict her. It is the portrait–like format and all its associations that confirm the reality of this sacred person. The images must be thought of as pictorial examples of what one might call the urgency of similitude that pervaded devotional literature of the period. Because of the pressures of the Reformation and the suspicion with which images were viewed, beginning in the sixteenth century, Catholic theologians seemed to have used the idea of likeness to defend the use of images in devotion. The more the image was a reflection of its archetype, the less it was like an idol, or false image, hence the importance of the descriptions of the Virgin Mary.
Gender role masculinity and angry aggression in women

The extent to which gender role masculinity is related to degree of women's angry retaliation was investigated. The study also examined whether the relationship between gender role masculinity and anger is mediated by gender role differences in reactivity to provocation, or to differences in the labeling of anger. It was expected that the influence of gender role masculinity on affect and aggression would be greatest when the nature of the affective arousal is ambiguous. Sixty undergraduate women (predominantly upper middle class and white) were given a placebo pill. They were either given ambiguous information about the pill's effects, or were told it was a vitamin or a stimulant. They then were either provoked or not provoked, and finally received an opportunity to retaliate. The participants had been divided by median split into high- and low-masculinity groups based on their scores on Spence and Helmreich's (1978) Personal Attributes Questionnaire. As expected, when provoked, high-masculinity subjects were more aggressive than low-masculinity subjects but only in the ambiguous drug information condition. Although they reported more arousal-related sensations, they did not rate themselves higher in anger. The results are discussed in terms of gender role influences on the experience of anger and the expression of aggression.
Band-limited Green's Functions for Quantitative Evaluation of Acoustic Emission Using the Finite Element Method

A method of numerically estimating dynamic Green's functions using the finite element method is proposed. These Green's functions are accurate in a limited frequency range dependent on the mesh size used to generate them. This range can often match or exceed the frequency sensitivity of the traditional acoustic emission sensors. An algorithm is also developed to characterize an acoustic emission source by obtaining information about its strength and temporal dependence. This information can then be used to reproduce the source in a finite element model for further analysis. Numerical examples are presented that demonstrate the ability of the band-limited Green's functions approach to determine the moment tensor coefficients of several reference signals to within seven percent, as well as accurately reproduce the source-time function.
HYDROGEN MOVEMENT INTO AND OUT OF FLUID INCLUSIONS IN QUARTZ : EXPERIMENTAL EVIDENCE AND GEOLOGIC IMPLICATIONS

Abstract Natural chalcopyrite-bearing fluid inclusions from the Red Mountain, Arizona, porphyry copper prospect have been used to experimentally document the movement of hydrogen into and out of fluid inclusions in quartz. Chalcopyrite daughter minerals in inclusions do not dissolve during heating studies of “as collected” quartz vein material. However, after the samples were held at an elevated (but unknown) hydrogen pressure in a cold-seal-type pressure vessel at 600°C and 2.5 kbar for seven days, chalcopyrite daughter crystals in fluid inclusions dissolve easily and completely during subsequent heating. The presence of hydrogen in the re-equilibrated inclusions was confirmed by both Raman microprobe and quadrupole mass spectrometric analyses of the inclusions. Repeated heating of re-equilibrated inclusions to measure the dissolution temperature of chalcopyrite (Tm Cpy) results in a considerably higher Tm Cpy during each successive run until, eventually, the chalcopyrite no longer dissolves when heated to the upper limit of the heating stage. This behavior is interpreted to indicate that hydrogen which had diffused into inclusions during re-equilibration experiments diffused out of the inclusions during microthermometric analyses. The dissolution of chalcopyrite following re-equilibration and its failure to dissolve before re-equilibration are consistent with proposed solubility models for chalcopyrite in aqueous solutions. The rapid movement of hydrogen into inclusions is also consistent with experimentally determined diffusion rates for hydrogen through quartz. These results reinforce conclusions reached by earlier workers who suggested that the failure of some fluid inclusion daughter minerals to dissolve during heating is a result of hydrogen loss. These results also support earlier workers who have suggested that unexpectedly low δD values obtained from inclusion fluids were produced by the preferential movement of hydrogen (relative to deuterium) into fluid inclusions. Finally, these results suggest that ƒ o 2 conditions inferred from Raman or other microanalytical data obtained from fluid inclusions may not represent ƒ O 2 conditions present at the time of trapping.
Cocaine’s Effects on Neuroendocrine Systems: Clinical and Preclinical Studies

This review examines the effects of cocaine on the neuroendocrine system and summarizes findings from clinical studies of cocaine abusers and preclinical studies in rodents and rhesus monkeys. The effects of acute and chronic cocaine administration on anterior pituitary, gonadal, and adrenal hormones are described, and the functional consequences of chronic cocaine exposure are discussed. Many of cocaine's acute effects on the endocrine system are consistent with its actions as a monoamine reuptake inhibitor. Acute cocaine administration stimulates release of gonadotropins, ACTH, and cortisol or corticosterone and suppresses prolactin levels. It has been difficult to detect changes in basal levels of most hormones or alterations in hormone responsiveness to a challenge dose of cocaine or other agents after chronic cocaine treatment. Interpretation of clinical data is often complicated by polydrug abuse involving opiates and alcohol as well as cocaine. However, preclinical studies of the effects of chronic cocaine exposure on integrated neuroendocrine function have revealed disruptions of the estrous cycle in rats and the menstrual cycle in rhesus monkeys. Furthermore, the menstrual cycle disorders observed in rhesus monkeys parallel those reported in women who abuse cocaine. Much remains to be learned about cocaine's interactions with the endocrine system and the consequences of cocaine abuse for reproductive function.
Fatty acid metabolism via triglyceride in the salmon heart.

Abstract The composition of heart lipids was analyzed and the metabolism of heart triglycerides investigated in pre- and post-spawning pink salmon (Oncorhyncus gorbuscha). Comparison of the two kinds of fish indicated that the latter have smaller hearts containing less total lipid. The most notable finding involved virtually complete loss, on average 94%, of heart triglycerides during the fresh water migration to the spawning grounds. In vivo palmitate-1-14C incorporation into heart triglycerides, as well as heart slice incubations, revealed the triglyceride pathway as an active metabolic route even in post-spawning fish that were only hours from death. The heart took up and retained fatty acid from the serum more readily than liver, skeletal muscle or brain. Following intravenous injection of the label, maximum specific activity of heart triglycerides was achieved in approximately one hour. The rapid turnover of the glyceride pool coupled with its diminishing mass is evidence of a substantial fatty acid flow through this intermediate in the heart muscle.
Virus Infection Leads to Localized Hyperacetylation of Histones H3 and H4 at the IFN-β Promoter

Abstract Transcriptional activation of the human interferon-β (IFN-β) gene by virus infection requires the assembly of a higher order nucleoprotein complex, the enhanceosome, which consists of the transcriptional activators NF-κB (p50/p65), ATF-2/c-jun, IRF-3 and IRF-7, architectural protein HMGI(Y), and the coactivators p300 and CBP. In this report, we show that virus infection of cells results in a dramatic hyperacetylation of histones H3 and H4 that is localized to the IFN-β promoter. Furthermore, expressing a truncated version of IRF-3, which lacks a p300/CBP interaction domain, suppresses both histone hyperacetylation and activation of the IFN-β gene. Thus, coactivator-mediated localized hyperacetylation of histones may play a crucial role in inducible gene expression.
Investigation by EPR and ENDOR spectroscopy of the novel 4Fe ferredoxin fromPyrococcus furiosus

The hyperthermophilic archaeonPyrococcus furiosus contains a four-Fe ferredoxin (Pf- Fd) that differs from most other 4Fe-Fd’s in that its [Fe4S4] cluster is anchored to protein by only three cysteinyl residues.Pf- Fd also is of interest because in its reduced form, [Fe4S4]+, the cluster exhibits bothS = 1/2 andS = 3/2 spin states. Addition of excess cyanide ion converts the cluster exclusively to anS = 1/2 state (g1 = 2.09, g2 = 1.95, g3 = 1.92), however dialysis restores the EPR signal of native reduced protein indicating that the cluster is not irreversibly altered by cyanide. Both the native protein and protein in the presence of excess cyanide ion (Pf- Fd 4Fe-CN) were investigated here using the techniques of electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) spectroscopy. In particular,Pf- Fd 4Fe-CN was investigated using13CN− and C15N− ligands.13C and15N ENDOR indicated that a single cyanide ion bound directly, with the cluster showing an unusually small contact interaction (aiso(13C)∼ −3 MHz, aiso(15N) ∼ 0). This is in contrast to cyanide bound to monomeric low-spin Fe(III)-containing proteins such as transferrin and myoglobin, for which the13C hyperfine coupling has a large isotropic component (aiso(13C) ≈ −30 MHz). This small contact interaction is not due to low spin density of Fe, as57Fe ENDOR of the singly and triply labeledPf- Fd 4FeCN isotopologs, [57FeFe3S4]+ and [Fe57Fe3S4]+, show hyperfine coupling characteristic for [Fe4S4]+ clusters, particularly for the Fe to which cyanide binds. Thus, the low spin density on13C is not due to low spin density on the Fe ion to which it binds. Further theoretical work is needed to explain the contrast between the strong electronic effect of cyanide ion binding with the low spin density on the ligand.
Factors Affecting Morbidity and Mortality of Roux-en-Y Gastric Bypass for Clinically Severe Obesity: An Analysis of 1,000 Consecutive Open Cases by a Single Surgeon

Determinants of perioperative risk for RYGB are not well defined. Retrospective analysis of comorbidities was used to evaluate predictors of perioperative risk in 1,000 consecutive patients having open RYGB by univariate analyses and logistic regression. One hundred forty-six men, 854 women; average age 38.3 ± 11.2 years; mean BMI 51.8 ± 10.5 (range 24–116) were evaluated. Average hospital stay (LOS) was 3.8 days; 87% 50 (0.6 vs 2.3%, p = 0.03) and male sex were associated with increased mortality (1.3 vs. 4.0%, p = 0.02). Sex-specific logistic regression demonstrated males with angiographically proven CAD were more likely to die (p = 0.028) than matched cohorts. Age (p = 0.033) and sleep apnea (p = 0.040) were significant predictors of death for women. Perioperative mortality after RYGB appears to be affected by sex, BMI, age, CAD, and sleep apnea. Strategies employing risk stratification should be developed for bariatric surgery.
Molecular structure of troponin C from chicken skeletal muscle at 3Å resolution

Troponin C is the Ca2+-binding subunit of the troponin complex and is involved in the calcium control of muscle contraction. The X-ray structure of chicken TnC has been determined at 3A resolution using a single heavy atom derivative and application of a novel phase improvement and phase extension procedure. The protein has an unusual dumbbell-shape with a length of about 70A. The N- and C-domains are connected by a single long α-helix of about 9 turns. Two metal binding sites (the Ca2+-Mg2+ sites) in the C-domain are occupied by metal ions in the crystals and the helix-loop-helix Ca2+ -binding folds are very similar to those in other known Ca2+ -binding proteins. In contrast, the Ca2+ -specific sites in the N-domain appear unoccupied and the two putative Ca2+ -binding folds have a vastly different structural arrangement. The conformational rearrangements in the N-domain upon Ca2+ binding are believed to be the trigger for a cascade of protein-protein interaction alterations which lead to muscle contraction.
Iron doped amorphous hydrogenated carbon nitride

Abstract Amorphous carbon nitride iron-containing thin films have been grown from the plasma decomposition of a feedstock of CH4, N2, and H2. From Auger Electron Spectroscopy, these films contain C, N, O, Fe and a small amount of Cr and Ni. The presence of Fe, Cr and Ni is due to sputtering of the stainless steel cathode. From Hall and thermopower measurements, these films are p-type degenerate semiconductors. From transmission electron microscopy, these films contain microcrystallites of FeO embedded in an amorphous matrix.
Thermal Aging of Heterophasic Propylene−Ethylene Copolymers: Morphological Aspects Based on ESR, FTIR, and DSC

Electron spin resonance (ESR) spectra of nitroxide radicals formed in thermally treated heterophasic propylene−ethylene copolymers (HPEC) containing bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Tinuvin 770) as a hindered amine stabilizer (HAS) were studied in the temperature range 100−433 K; the nitroxides are derived from the HAS and are termed HAS−NO. The results were compared with ESR spectra of the same radicals obtained first by oxidation of Tinuvin 770 and then doped in HPEC and related homopolymers polyethylene (PE) and polypropylene (PP); these nitroxides are termed spin probes. ESR spectra indicated that HAS−NO and the spin probes in HPEC and homopolymers reside in a range of amorphous sites differing in their dynamical properties. Evidence for the various sites was obtained from the ESR line widths, the temperature variation of the extreme separation in the ESR spectra, and the effect of stress on the ratio of the fast and slow components in the spectra of HAS−NO in thermally treated HPEC. T...
Critical thermal tolerance polygons of tropical marine fishes from Sulawesi, Indonesia

Abstract 1. Replicate thermal tolerance polygons were created using critical thermal methodology (CTM) and statistically compared. 2. Reef-associated damselfish and cardinalfish displayed the smallest total and intrinsic polygon zones and equal upper and lower acquired tolerance zones within species. 3. Two gobiids and a mullet species (resident and transient to tidepools, respectively) showed greater total and intrinsic tolerance zones than reef-associated species. 4. These CTM-polygons assess the thermal biology of fishes in habitats sensitive to global climate change and suggest that tropical Indo-Pacific fishes are likely to be affected by indirect consequences of global climate change, rather than by direct temperature mortality.
The anion gap does not accurately screen for lactic acidosis in emergency department patients

Introduction: Lactic acidosis portends a poor prognosis in trauma, sepsis, and other shock states and is useful for triaging and resuscitating emergency department (ED) patients. The authors sought to determine whether the AG is a reliable screen for lactic acidosis when applied specifically in the ED setting. Methods: The authors performed a retrospective cohort study over a seven month period. Subjects were all ED patients that had a serum lactate obtained. Sensitivity analyses of the AG for detecting presence of lactic acidosis were calculated for the traditional AG normal value (AG Results: Serum lactate levels were ordered in the ED on 440 occasions. 137 samples were excluded by protocol. Using an AG cutoff of 12, the sensitivity for detecting lactic acidosis was 58.2%, specificity was 81.0%, and the negative predictive value was 89.7%. Using the AG cutoff of 6, the sensitivity was 93.2%, the specificity was 17.3%, and the negative predictive value was 91.8%. Conclusions: The traditional definition of AG >12 was insensitive for the presence of lactic acidosis. Using the revised AG of >6 is more sensitive but non-specific for lactic acidosis. The authors conclude that employing the AG as a screen for LA may be inappropriate in ED patients. Instead, they recommend ordering a serum lactate immediately upon suspicion of a shock state. A prospective study to confirm these findings is needed.
Changing Frequency of Heavy Rainfall over the Central United States

AbstractRecords of daily rainfall accumulations from 447 rain gauge stations over the central United States (Minnesota, Wisconsin, Michigan, Iowa, Illinois, Indiana, Missouri, Kentucky, Tennessee, Arkansas, Louisiana, Alabama, and Mississippi) are used to assess past changes in the frequency of heavy rainfall. Each station has a record of at least 50 yr, and the data cover most of the twentieth century and the first decade of the twenty-first century. Analyses are performed using a peaks-over-threshold approach, and, for each station, the 95th percentile is used as the threshold. Because of the count nature of the data and to account for both abrupt and slowly varying changes in the heavy rainfall distribution, a segmented regression is used to detect changepoints at unknown points in time. The presence of trends is assessed by means of a Poisson regression model to examine whether the rate of occurrence parameter is a linear function of time (by means of a logarithmic link function). The results point to...
Skeletal configurations of ribbon trees

The straight skeleton construction creates a straight-line tree from a polygon. Motivated by moduli spaces from algebraic geometry, we consider the inverse problem of constructing a polygon whose straight skeleton is a given tree. We prove there exists only a finite set of planar embeddings of a tree appearing as straight skeletons of convex polygons. The heavy lifting of this result is performed by using an analogous version of Cauchy's arm lemma. Computational issues are also considered, uncovering ties to a much older angle bisector problem.
Involvement of the orexin/hypocretin system in ethanol conditioned place preference

Rationale Recent studies suggest that orexin/hypocretin is involved in drug reward and drug-seeking behaviors, including ethanol self-administration. However, orexin’s role in ethanol-induced seeking behaviors remains unclear.
Identification and Confirmation of Quantitative Trait Loci for Root Rot Resistance in Snap Bean

Root rot, caused by several pathogens including Pythium ultimum Trow and Aphanomyces euteiches Drechs f. sp. phaseoli W.F. Pfender and D.J. Hagedorn, is an important disease complex of snap bean (Phaseolus vulgaris L.). The objectives of this study were to identify, map, and validate markers associated with root rot resistance in three snap bean populations. An 'Eagle' x 'Puebla 152' recombinant inbred line (RIL) population was evaluated for root rot by plant stand percentage, plant vigor, and plant biomass. Field data were combined with a random amplified polymorphic DNA (RAPD) map to identify quantitative trait loci (QTL) associated with resistance using composite interval mapping. In addition, two inbred backcross (IBC) populations (EEP and EPH) derived from a cross (Eagle x Puebla 152) to Eagle and 'Hystyle' respectively were evaluated. Five regions from linkage groups B6, B3, and B7 of the P. vulgaris core map were associated with QTL for root rot resistance. High levels of resistance were also observed in several lines of the IBC populations. A major QTL for root rot resistance was associated with the tightly linked AD9.950 and S18.1500 RAPD marker alleles from linkage group B6 in the RIL population and confirmed explaining 25 to 49% of the variability for plant vigor and biomass in the IBC populations. The exploitation of the linkage disequilibrium between the AD9.950 and S18.1500 RAPD markers derived from Puebla 152 and Eagle can facilitate the development of root rot resistant cultivars.