cssi/SciSciGPT-SciSciNet huggingface dataset:
THE M3 MUSCARINIC ACETYLCHOLINE RECEPTOR DIFFERENTIALLY REGULATES CALCIUM INFLUX AND RELEASE THROUGH MODULATION OF MONOVALENT CATION CHANNELS

Several types of transmembrane receptors regulate cellular responses through the activation of phospholipase C-mediated Ca2+ release from intracellular stores. In non-excitable cells, the initial Ca2+ release is typically followed by a prolonged Ca2+ influx phase that is important for the regulation of several Ca2+-sensitive responses. Here we describe an agonist concentration-dependent mechanism by which m3 muscarinic acetylcholine receptors (mAChRs) differentially regulate the magnitude of the release and influx components of a Ca2+ response. In transfected Chinese hamster ovary cells expressing m3 mAChRs, doses of the muscarinic agonist carbachol ranging from 100 nM to 1 mM evoked Ca2+ release responses of increasing magnitude; maximal Ca2+ release was elicited by the highest carbachol concentration. In contrast, Ca2+ influx was maximal when m3 mAChRs were activated by moderate doses (1-10 microM) of carbachol, but substantially reduced at higher agonist concentrations. Manipulation of the membrane potential revealed that the carbachol-induced Ca2+ influx phase was diminished at depolarized potentials. Importantly, carbachol doses above 10 microM were found to couple m3 mAChRs to the activation of an inward, monovalent cation current resulting in depolarization of the cell membrane and a selective decrease in the influx, but not release, component of the Ca2+ response. These studies demonstrate, in one experimental system, a mechanism by which a single subtype of G-protein-coupled receptor can utilize the information encoded in the concentration of an agonist to generate distinct intracellular Ca2+ signals.
The ubiquitin proteasome system in human cardiomyopathies and heart failure

Maintenance of protein quality control is a critical function of the ubiquitin proteasome system (UPS). Evidence is rapidly mounting to link proteasome dysfunction with a multitude of cardiac diseases, including ischemia, reperfusion, atherosclerosis, hypertrophy, heart failure, and cardiomyopathies. Recent studies have demonstrated a remarkable level of complexity in the regulation of the UPS in the heart and suggest that our understanding of how UPS dysfunction might contribute to the pathophysiology of such a wide range of cardiac afflictions is still very limited. Whereas experimental systems, including animal models, are invaluable for exploring mechanisms and establishing pathogenicity of UPS dysfunction in cardiac disease, studies using human heart tissue provide a vital adjunct for establishing clinical relevance of experimental findings and promoting new hypotheses. Accordingly, this review will focus on UPS dysfunction in human dilated and hypertrophic cardiomyopathies and highlight areas rich for further study in this expanding field.
INPAC: An Enforceable Incentive Scheme for Wireless Networks using Network Coding

Wireless mesh networks have been widely deployed to provide broadband network access, and their performance can be significantly improved by using a new technology called network coding. In a wireless mesh network using network coding, selfish nodes may deviate from the protocol when they are supposed to forward packets. This fundamental problem of packet forwarding incentives is closely related to the incentive compatible routing problem in wireless mesh networks using network coding, and to the incentive compatible packet forwarding problem in conventional wireless networks, but different from both of them. In this paper, we propose INPAC, the first incentive scheme for this fundamental problem, which uses a combination of game theoretic and cryptographic techniques to solve it. We formally prove that, if INPAC is used, then following the protocol faithfully is a subgame perfect equilibrium. To make INPAC more practical, we also provide an extension that achieves two improvements: (a) an online authority is no longer needed; (b) the computation and communication overheads are reduced. We have implemented and evaluated INPAC on the Orbit Lab testbed. Our evaluation results verify the incentive compatibility of INPAC and demonstrate that it is efficient.
Book Review: Phone Clones: Authenticity Work in the Transnational Service Economy

Kiran Mirchandani, Phone Clones: Authenticity Work in the Transnational Service Economy, Cornell University Press, 2012.
Selenium uptake by plants: Effects of soil steaming, root addition, and selenium augmentation

Abstract A greenhouse study was conducted to evaluate the effects of soil steaming, root additions, and selenium (Se) supplements on the uptake of Se by two plant species, yellow sweet clover [Melilotus officinalis (L.) Pallas], and fourwing saltbush [Atriplex canescens (Pursh) Nutt.]. Although treatments used to test the effects of vesicular‐arbuscular mycorrhizae (VAM) did not result in differences in Se uptake, both species of plants had significantly lower Se concentrations when grown in steamed soil (65–80°C, 14h). Whereas soil steaming did not affect the growth of yellow sweet clover, growth of fourwing saltbush was significantly enhanced. Root additions, added as mycorrhizal inoculum, had no effect on the growth parameters or Se uptake of the plants, but did enhanced VAM colonization of yellow sweet clover. Selenium (3 mg Se kg‐1) added as selenite (SeO3 2‐) increased plant Se concentrations, although selenate (SeO4 2‐) was fatal to most seedlings. Phosphate‐extractable soil Se concentrations were ...
Directional correlation measurements in 86Sr

Abstract Directional correlation measurements have been made on γ-rays of 86 Sr following the electron-capture and positon decay of 86 Y. The 1077 keV γ-ray (from the 2 + first excited state) was detected in a NaI(Tl) crystal in coincidence with a 20 cm 3 Ge(Li) detector. Three cascade correlations (involving the 777 keV, 1153 keV and 1921 keV γ-rays) and two 1–3 correlations (intermediate radiation unobserved) are reported. The 777 keV transition (from the 2 + state at 1854 keV) is found to be M1 + E2 with 7 ± 2 % quadrupole content. The directional correlation results, together with additional experimental evidence, lead to assignments of 4 + , 3 − , 5 − and 3 − to the states of 2230 keV, 2482 keV, 2673 keV and 2997 keV, respectively.
Metabolic stress in isolated mouse ventricular myocytes leads to remodeling of t tubules.

Cardiac ventricular myocytes possess an extensive t-tubular system that facilitates the propagation of membrane potential across the cell body. It is well established that ionic currents at the res...
Two Dimensional Phase Unwrapping for Coherent Imaging

We describe a phase unwrapping algorithm for digital holographic images. The algorithm uses preprocess smoothing, phase gradient calculations, and amplitude measures to determine the reliability of a given data point, and follows a non-continuous path.
Foliar 15N natural abundance in Hawaiian rainforest: patterns and possible mechanisms.

Foliar samples were obtained from symbiotic nitrogen-fixers and control plants (non-fixers) along elevational and primary successional gradients in volcanic sites in Hawai'i. Most control plants had negative δ15N values (range-10.1 to +0.7‰), while most nitrogen-fixers were near 0‰. Foliar 15N in the native tree Metrosideros polymorpha did not vary with elevation (from sea level to tree-line), but it did increase substantially towards 0‰ on older soils. The soil in an 197-yr-old site had a δ15N value of approximately-2‰, while in a ∼67000-yr-old site it was +3.6‰. We suggest that inputs of 15N-depleted nitrogen from precipitation coupled with very low nitrogen outputs cause the strongly negative δ15N values in non-nitrogen-fixing plants on early successional sites.
A proposal for the generation of ultra-short X-ray pulses

In this paper it is shown that optical stochastic cooling in a 150 MeV electron storage ring will allow production of a beam with longitudinal emittance 4.5 {times} 10{sup {minus}6} MeV{center_dot}m. Such a small emittance accompanied with a bunch compression technique based upon the transformation in the longitudinal phase space will allow achieving a bunch length 30 {mu}m. This bunch could then be used for the generation of ultra-short x-ray pulses by the Compton scattering of laser photons.
Investigations of twin boundary fatigue cracking in nickel and nitrogen-stabilized cold-worked austenitic stainless steels

Abstract Implant retrieval studies have indicated that the primary cause of failure in stainless steel devices is fatigue, and time or cycles required for fatigue crack initiation often consumes the majority of implant lifetime. Stainless steels with significant nitrogen additions have shown an improved fatigue response, but have also shown a peculiar preference for fatigue crack initiations at or along annealing twin boundaries in the face-centered cubic (FCC) materials. In a recent comparison study on cold-worked implant grade stainless steels, a number of fatigue crack initiations were found along former annealing twin boundaries on both nitrogen-stabilized austentitic (HNASS) and nickel-stabilized austenitic steels. Further investigations were warranted to determine the crystallographic conditions present around these annealing twin boundary cracks, since not every twin boundary showed crack initiation. The present study examined the crystallographic conditions present around each of the former annealing twin boundary cracks relative to the applied loading direction. It was determined that the former annealing twin boundary cracks showed the complete range of misorientation deviations allowed by the Brandon criterion. The textures of the cracked twin boundaries were found to be random relative to the overall global textures of the materials. Most of the cracked twin planes in the HNASS steel were shown to be high angles, and in many cases were nearly perpendicular to the material surface. The nickel-stabilized steel showed a preference for lower twin plane inclination angles relative to the material surface. High Schmid factors were shown for all grains surrounding the cracked twin boundaries indicating each grain was oriented favorably for slip relative to the applied loading direction. A high Taylor factor mismatch was also shown across most of the cracked twin boundaries in both steels indicating strong difference in expected yield response for each of the grains which suggest localized strain incompatibility was another important factor in twin boundary cracking.
Translocal style communities: Hip hop youth as cultural theorists of style, language, and globalization

This article addresses issues that lie at the intersection of debates about language, Hip Hop Culture, and globalization. Critically synthesizing a wide range of recent work on Hip Hop and foregrounding issues of youth agency as evidenced by Hip Hop youth’s metalinguistic theorizing, the article presents an empirical account of youth as cultural theorists. Hip Hop youth are both participants and theorists of their participation in the many translocal style communities that constitute the Global Hip Hop Nation. Highlighting youth agency, the article demonstrates that youth are engaging in the agentive act of theorizing the changes in the contemporary world as they attempt to locate themselves at the intersection of the local and the global. The article concludes by calling for a linguistic anthropology of globalization characterized by ethnographic explorations of and a theoretical focus on popular culture, music, and mass-mediated language as central to an anthropological understanding of linguistic processes in a global era.
The potential of adipokinetic hormone to teach us about neuropeptides.

Genetic manipulation and purification techniques are facilitating research into the biology of arthropod neuropeptides. The red pigment concentrating hormone (RPCH)/ adipokinetic hormone (AKH) family are a conserved group of peptides which were first recognized for their hormonal activities. Biosynthesis of AKH in the grasshopper seems to proceed via a large protein precursor (12 kDa) in the cell body of the neuron, which implies precise coordination of synthesis and neural activity. Beginning with a 10 amino acid stretch of known precursor protein sequence, an oligonucleotide primer approach is being used to clone a recombinant AKH gene. Once achieved, this will allow fundamental questions on the biochemistry and physiology of neuropeptides to be addressed. Such work in an arthropod system raises the intriguing possibility of studying neuropeptide level and synthetic activity in single, defined neurons.
Biomechanical Analysis of Embryonic Atrioventricular Valvulogenesis

Heart valve development is directed by a complex interaction of molecular and mechanical cues[1]. Both molecular and mechanical based approaches are needed to clarify these relationships. Many technologies exist for the former, but the short length scale and super-compliant material properties of embryonic valve tissue make conventional mechanical testing techniques ineffective. The pipette aspiration technique has been a useful tool in cell mechanics[2] and has recently been applied to adult valve leaflets[3]. Geometric effects of thin, planar tissues however compromise the utility of aspiration based measurements. Herein, we utilize pipette aspiration and a novel uni-axial micro-tensile testing apparatus to quantify the biomechanical evolution of avian embryonic heart valves. We then relate biomechanical stiffening to changes in underlying structural composition.Copyright © 2011 by ASME
Drug metabolism and toxicity during hypoxia.

Oxygen concentration affects the metabolism and toxicity of various drugs. A considerable amount of information is now available on the effects of hypoxia on the major pathways of drug metabolism, including oxidation (i.e., by cytochromes P-450, NAD+-dependent dehydrogenases, and monoamine oxidase), glucuronidation, sulfation, glutathione conjugation, glycine conjugation, and acetylation. Some pathways are essentially independent of O2 concentration while others are highly dependent upon O2. Certain drugs are activated to reactive and toxic metabolites by O2-dependent pathways. This aspect of drug toxicity serves as a basis for treatment of slow-growing solid tumors which have hypoxic regions that are resistant to chemo- and radiation therapies. Recent studies have also established that hypoxic cells have increased susceptibility to oxidative injury, and this can predispose cells to other pathological processes. However, in spite of the available knowledge concerning the O2 dependence of metabolism and toxicity of drugs, relatively little is known about the effects of chronic hypoxia on the expression of drug-metabolizing enzymes or upon the absorption, elimination, or toxicity of drugs. Thus, in addition to the information presently reviewed, major gaps exist in the knowledge needed to provide optimal drug therapy in the large population of patients who experience O2 deficiency. Comments and Perspectives. Specific basic research areas which need to be studied include the effects of hypoxia on drug absorption and elimination, the changes of neahypoxia that lead to enhanced susceptibility to drug toxicity, and the effects of chronic hypoxia on the metabolic systems involved in absorption, metabolism, and elimination of drugs. At an applied level, the available data on the O2 dependences of drug metabolism pathways need to be extended to examine in detail the O2 dependence to metabolism and toxicity of relevant, currently used therapeutic agents. Such efforts can be expected to continue to improve drug therapies and reduce toxicities in hypoxic patients.
Cyanide as a copper and quinone-directed inhibitor of amine oxidases from pea seedlings ( Pisum sativum) and Arthrobacter globiformis: evidence for both copper coordination and cyanohydrin derivatization of the quinone cofactor.

The interactions of cyanide with two copper-containing amine oxidases (CuAOs) from pea seedlings (PSAO) and the soil bacterium Arthrobacter globiformis (AGAO) have been investigated by spectroscopic and kinetic techniques. Previously, we rationalized the effects of azide and cyanide for several CuAOs in terms of copper coordination by these exogenous ligands and their effects on the internal redox equilibrium TPQamr-Cu(II)⇌TPQsq-Cu(I). The mechanism of cyanide inhibition was proposed to occur through complexation to Cu(I), thereby directly competing with O2 for reoxidation of TPQ. Although cyanide readily and reversibly reacts with quinones, no direct spectroscopic evidence for cyanohydrin derivatization of TPQ has been previously documented for CuAOs. This work describes the first direct spectroscopic evidence, using both model and enzyme systems, for cyanohydrin derivatization of TPQ. K d values for Cu(II)-CN− and Cu(I)-CN−, as well as the K i for cyanide inhibition versus substrate amine, are reported for PSAO and AGAO. In spite of cyanohydrin derivatization of the TPQ cofactor in these enzymes, the uncompetitive inhibition of amine oxidation is determined to arise almost exclusively through CN− complexation of Cu(I).
19th-Century American Women's Novels: Interpretative Strategies.

Acknowledgments Part I. Introduction: Part II. Narrative Designs and Textual Rebellions: 1. Preludes: the early didactic novel: Narrative control in Charlotte Temple and A New-England Tale 2. Introduction to the exploratory text: subversions of the narrative design in St Elmo 3. Decoding the exploratory text: subversions of the narrative design in Queechy Part III. Narrative Rebellions and Textual Designs: 4. Inscribing and defining: the many voices of Fanny Fern's Ruth Hall 5. Extending and subverting: the iconography of houses in The Deserted Wife 6. Projecting the 'I'/conoclast: first-person narration in The Morgesons Part IV. The Later Didactic Novel: 7. Narrative control and thematic radicalism in work and The Silent Partner Part V. Conclusions and Implications: 8. Anomalies and anxieties: The Story of Avis, A Country Doctor, The Awakening, O Pioneers! Notes General index Index to diaries, letters and reviews Index to literary and historical references.
A novel etch method for TaBO/TaBN EUVL masks

Etching of TaBO/TaBN absorbers on EUVL masks was studied. The self-mask strategy and etch selectivity optimization were used for obtaining the best etch CD performance. Gibbs Energy Minimization was used for determining etch gas selection and product volatility. Calculated results suggest the use of a two-step etch process, i.e. using fluorinecontaining gas to etch the antireflective (AR) layer and using chlorine-containing gas to etch the bulk absorber beneath AR. High selectivity of TaBN-to-TaBO was obtained and the AR hard mask function was proven. By using this method, one EUVL mask can be used many times by selectively exposing portions of a mask during etch. A profilometer was used for etch product characterization and etch CD results were verified by using CD SEM measurement. Optimal conditions developed on the Applied Materials Tetra Mask Etch System by using just one mask gave etch CD bias of 3 nm, etch CD uniformity of <3 nm, excellent sidewall profile, and high selectivity of absorber layer to resist and absorber to buffer layer. Etch effects on the backside chrome coating were also examined. No arcing on the backside during EUVL absorber and buffer etching was identified.
Adaptive Games for Agile Spectrum Access Based on Extended Kalman Filtering

For dynamic spectrum allocation (DSA), distributed game has emerged as an attractive approach that enhances radio spectrum utilization efficiency at scalable complexity in network size. Cognitive radios act as game players to judiciously decide their transmission power spectrum density (TPSD) based on channel state information (CSI), which is generally estimated independently from the DSA games and may cause large computational and communication overheads. Particularly in the presence of doubly selective fading channels, a conventional DSA game needs to re-train the channel estimator and re-calculate the TPSD decisions for every transmission burst. To enable DSA intelligence at affordable costs, this paper proposes novel adaptive DSA algorithms based on channel tracking. Under the framework of extended Kalman filter (EKF), both the unknown CSI and the TPSD are modeled into a state vector that is to be tracked dynamically. This approach leads to EKF-based adaptive games that jointly track the CSI and update TPSD decisions, resulting in fast convergence and reduced communication overhead. Simulations are performed to testify the effectiveness of the proposed DSA algorithms, in terms of the achieved system spectrum efficiency, communication overhead, as well as resilience to user mobility
Single dose long-term suppression of testosterone secretion by a gonadotropin-releasing hormone antagonist (Antide) in male monkeys.

Abstract This study was designed to find the minimal single dose of Antide (Nal-Lys GnRH antagonist) that would provide long-term inhibition of serum testosterone levels in adult male monkeys. At 3 mg/kg (sc), Antide blocked testosterone secretion for only a few days. However, when the dose of Antide was raised to 10 mg/kg, some of the males manifested testosterone inhibition lasting more than 60 days, while shorter durations of action were found in others. These preliminary findings increase our interest in studying Antide as a potential male contraceptive agent, when combined with androgen replacement therapy, as well as for therapeutic applications in men having prostatic carcinoma. Importantly, Antide lacks the sometimes deleterious “flare” effect known to occur when GnRH agonists are used to treat these patients.
Influence of liver biopsy heterogeneity and diagnosis of nonalcoholic steatohepatitis in subjects undergoing gastric bypass.

Nonalcoholic fatty liver disease (NAFLD) is a chronic condition that can progress to cirrhosis and hepatocellular cancer. The most progressive form of NAFLD is nonalcoholic steatohepatitis (NASH). Currently, the only method to diagnose NASH is with a liver biopsy; however. sampling error may limit diagnostic accuracy. We investigated the discordance of paired liver biopsies in individuals undergoing gastric bypass. Two liver biopsies, composite size of ≥25 mm and ≥8 portal tracts (PTs), were obtained from the left lobe in 31 subjects. Group 1 included specimens at least 15 mm in length with ≥4 PTs compared to a second biopsy of at least 10 mm and ≥4 PTs (Group 2). The mean specimen size (number of PTs) for group 1 was 20.4 ± 4.2 mm (11.7 ± 5.5 PTs) and group 2 was 16.1 ± 5.3 mm (8.2 ± 4.1 PTs). Prevalence of NASH was 26% in Group 1 and 32% in Group 2. Sampling discordance was greatest for portal fibrosis (26%), followed by zone 3 fibrosis (13%) and ballooning degeneration (3%). The negative predictive values from Group 1 liver biopsies for NASH and portal fibrosis were only 83% and 67%, respectively. The results demonstrate that significant sampling variability exists in class 2 and 3 obese individuals undergoing screening liver biopsies for NAFLD. The degree and histopathological discordance is dependent upon zonal location and types of injury. Nevertheless, a 25-mm biopsy specimen without zone 3 cellular ballooning or fibrosis appears adequate to exclude the diagnosis of NASH.
Pharmacological characterization of the specific binding of [3H]ryanodine to rat brain microsomal membranes

High-affinity binding of [3H]ryanodine has been characterized in rat brain microsomal fractions. Membrane fractions from 4 brain regions (cerebral cortex, cerebellum, hippocampus and brainstem) have been isolated using sucrose density gradient purification. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed the presence of a high-molecular weight protein (Mr approximately 320 kDa), similar to that of ryanodine receptor from muscle sarcoplasmic reticulum (SR). In the presence of high salt (1 M KCl), [3H]ryanodine binds to low density (0.8 M sucrose) cortical microsomal fraction with high affinity (Kd 1.5 nM), and with the highest capacity (Bmax 330 fmol/mg protein). Kinetic analysis of the binding suggests multiple available binding sites for ryanodine. Binding of ryanodine is Ca2+ dependent (ED50 1 microM) and inhibited by Mg2+ and Ruthenium red. Adenine nucleotides have a biphasic effect on the binding of [3H]ryanodine. At low Ca2+ concentration caffeine and daunorubicin enhance the binding of [3H]ryanodine. The inositol 1,4,5-trisphosphate (IP3) binding inhibitor, heparin, has no effect on ryanodine binding, and ryanodine and caffeine do not influence the binding of [3H]IP3, which is enriched in the cerebellar fractions. These data demonstrate significant quantitative differences in the pharmacology of brain and muscle receptors and raise the question as to the physiological role of ryanodine binding proteins in the central nervous system and whether it is coupled to an endoplasmatic reticulum (ER) Ca2+ release channel.
Variance of ion-electron coefficients with atomic number of impacting ions

Abstract The relation between ion-electron coefficients γ and atomic number Z1 of impacting ions on the electron multiplier of a mass spectrometer was investigated. Ions of 22 elements ranging from Li to Pb were measured on three dynode materials (CuBe, Al and Ni) for an ion energy of 8.0 keV. These results were extrapolated to ion-electron coefficients for constant ion velocity. The ion-electron coefficients obtained for constant ion velocity were combined with results given by Lao et al. [2] to form a set of 44 coefficients for the CuBe dynode. A periodic increase of γ(Z1) at constant velocity was found for the dynode materials used. The trend of this increase agrees well with theory. Maxima in γ(Z1) appeared for the noble gases and for group IVb, minima for groups IIa and IIb. The dynode material influenced the amplitude of the oscillations in γ(Z1), but did not affect the location of maxima and minima in γ(Z1). The comparison of the results obtained for γ(Z1) showed good agreement with the periodicity found for electronic stopping.
Elevation of serum aluminum in humans on a two-day sucralfate regimen.

Serum aluminum concentrations were determined in ten healthy subjects treated with phenytoin 500 mg and with sucralfate and phenytoin in a crossover fashion. Each subject received four 1,000-mg sucralfate tablets between 8 AM and 10 PM one day before the study, and this was repeated during the study day. A total of eight doses of sucralfate was administered over the two-day period. Serum samples were drawn at 0, 2, 4, 8, 12, 24, 32, and 48 hours after administration. The areas under the serum aluminum concentration-time curves before and after sucralfate (mean +/- SD) were 496.0 +/- 80.9 and 770.9 +/- 146.6 hr-ng/mL, respectively. This increase is statistically significant (P less than .01), indicating that serum aluminum levels are elevated even after two days of treatment with sucralfate. The results from this study are not in agreement with the only other report on this subject.
Role of 4-Hydroxybutyrate-CoA Synthetase in the CO2 Fixation Cycle in Thermoacidophilic Archaea

Metallosphaera sedula is an extremely thermoacidophilic archaeon that grows heterotrophically on peptides and chemolithoautotrophically on hydrogen, sulfur, or reduced metals as energy sources. During autotrophic growth, carbon dioxide is incorporated into cellular carbon via the 3-hydroxypropionate/4-hydroxybutyrate cycle (3HP/4HB). To date, all of the steps in the pathway have been connected to enzymes encoded in specific genes, except for the one responsible for ligation of coenzyme A (CoA) to 4HB. Although several candidates for this step have been identified through bioinformatic analysis of the M. sedula genome, none have been shown to catalyze this biotransformation. In this report, transcriptomic analysis of cells grown under strict H2-CO2 autotrophy was consistent with the involvement of Msed_0406 and Msed_0394. Recombinant versions of these enzymes catalyzed the ligation of CoA to 4HB, with similar affinities for 4HB (Km values of 1.9 and 1.5 mm for Msed_0406 and Msed_0394, respectively) but with different rates (1.69 and 0.22 μmol × min−1 × mg−1 for Msed_0406 and Msed_0394, respectively). Neither Msed_0406 nor Msed_0394 have close homologs in other Sulfolobales, although low sequence similarity is not unusual for acyl-adenylate-forming enzymes. The capacity of these two enzymes to use 4HB as a substrate may have arisen from simple modifications to acyl-adenylate-forming enzymes. For example, a single amino acid substitution (W424G) in the active site of the acetate/propionate synthetase (Msed_1353), an enzyme that is highly conserved among the Sulfolobales, changed its substrate specificity to include 4HB. The identification of the 4-HB CoA synthetase now completes the set of enzymes comprising the 3HP/4HB cycle.
Physical methods for structure, dynamics and binding in immunological research

We present four experimental physical methods – X-ray and neutron diffraction, nuclear magnetic resonance spectroscopy, mass spectrometry and calorimetry – and two computational methods – molecular dynamics simulations and electrostatics calculations – which are general and widely applicable in the study of protein structure, dynamics and binding. These methods are useful tools for biologists that lead to structure–function, dynamics–function and binding–function correlations, in efforts to understand biomolecular function. Standard and emerging technologies within these methods are discussed and representative examples of applications in immunology are presented, from antigen–antibody, complement and MHC–T-cell receptor research. The examples demonstrate the power of the reviewed methods in immunological studies at the molecular level.
Building Civic Capacity Through an Elastic Local State: The Case of St. Louis

Since World War II the civic leadership of St. Louis has overcome the extreme fragmentation of public authority by building civic capacity through a variety of strategies and means. Three successive strategies for building civic capacity have unfolded in St. Louis to facilitate the revitalization of the downtown and other large-scale initiatives. Between 1950 and 1965 a regime strategy was employed in which city hall and the city's corporate elites shared a common vision for urban renewal and the significant national resources that were provided to meet that end. By the mid-1960s, however, a second strategy for downtown revitalization emerged that featured a corporate-centered politics during which time the successful assembly of civic capacity hinged largely on the ability of the mayor to present and provide projects in which corporate elites and their companies would be willing investors. Since the early 1990s, building the civic capacity to undertake large initiatives has been made possible through the creation of a constellation of quasi-public corporations and special districts. This third strategy of “shadow governments” are the most recent means of achieving civic capacity in St. Louis and we argue in this article that these new institutions are transforming the local state because they are capable of forging political coalitions, mobilizing resources, and making decisions that transcend general-purpose governmental jurisdictions. For cities and for urban regions, the importance of this development is far-reaching.
Racial differences in the search for housing: Do whites and blacks use the same techniques to find housing?

Abstract Studies report that real estate brokers often provide less information to black clients than to whites and steer them to different neighborhoods. However, few studies have investigated racial differences in housing search procedures. If blacks believe they will receive less useful information from brokers, they may avoid them. Analyzing 1992 data from Detroit, this study finds that blacks were significantly less likely than whites to consult brokers. Blacks tended to rely more on methods such as talking with friends, checking newspaper ads, or driving through neighborhoods. Blacks were also more likely to believe that they missed housing opportunities because brokers discriminate. Differences in the socioeconomic characteristics of subjects account for some of the differences in the use of brokers. Eradicating discrimination by brokers will broaden housing opportunities only for blacks who use brokers. Policy actions that address the perception of discrimination by brokers may be a more powerful ...
A simple technique for continuous measurement of time-variable gas transfer in surface waters

Mass balance models of dissolved gases in streams, lakes, and rivers serve as the basis for estimating whole-ecosystem rates for various biogeochemical processes. Rates of gas exchange between water and the atmosphere are important and error-prone components of these models. Here we present a simple and efficient modification of the SF6 gas tracer approach that can be used concurrently while collecting other dissolved gas samples for dissolved gas mass balance studies in streams. It consists of continuously metering SF6-saturated water directly into the stream at a low rate of flow. This approach has advantages over pulse injection of aqueous solutions or bubbling large amounts of SF6 into the stream. By adding the SF6 as a saturated solution, we minimize the possibility that other dissolved gas measurements are affected by sparging and/or bubble injecta. Because the SF6 is added continuously we have a record of changing gas transfer velocity (GTV) that is contemporaneous with the sampling of other nonconservative ambient dissolved gases. Over a single diel period, a 30% variation in GTV was observed in a second-order stream (Sugar Creek, Indiana, USA). The changing GTV could be attributed in part to changes in temperature and windspeed that occurred on hourly to diel timescales.
Clinical evaluation of hormonal stress state in medical ICU patients: a prospective blinded observational study.

To evaluate whether classification of patients as having low, moderate, or high stress based on clinical parameters is associated with plasma levels of stress hormone Prospective, blinded, observational study in an 18-bed medical ICU. Eighty-eight consecutive patients Patients were classified as low (n=28), moderate (n=33) or high stress (n=27) on days 0 and 3 of ICU stay, based on 1 point for each abnormal parameter: body temperature, heart rate, systemic arterial pressure, respiratory rate, physical agitation, presence of infection and catecholamine administration. The stress categories were: high: 4 points or more, moderate 2–3 points, low 1 point. Plasma growth hormone (GH), insulin-like growth factor 1 (IGF-1), insulin, glucagon, cortisol were measured on days 0 and 3. Plasma cortisol and glucagon were significantly higher and IGF-1 lower in high vs. low stress patients on days 0 and 3. High stress patients were more likely to have high cortisol levels (odds ratio 5.8, confidence interval 1.8–18.9), high glucagon (8.7, 2.1–36.1), and low IGF-1 levels (5.9, 1.8–19.0) than low stress patients on day 0. Moderate stress patients were also more likely to have high cortisol and glucagon levels than low stress patients. Insulin and GH did not differ significantly. Results were similar for day 3. Moderate and severe stress was significantly associated with high catabolic (cortisol, glucagon) and low anabolic (IGF-1) hormone levels. The hormonal stress level in ICU patients can be estimated from simple clinical parameters during routine clinical evaluation.
Space and velocity focusing in time-of-flight mass spectrometers

A focusing equation is developed describing the relationship between space and velocity focusing for all one-dimensional time-of-flight mass spectrometers with constant electric fields. As a result of this equation, first-order double time focusing in one dimension is impossible. The possibility of large improvements in the resolving power of the time-of-flight mass spectrometers is discussed on this basis. The focusing equation also leads to an expression for the minimum time resolution obtainable. This second equation is applied to the conventional Wiley and McLaren (1955) two-field time-of-flight mass spectrometer with and without time-lag focusing, and to the mirror instrument of Karataev et al. (1972).
Anti-aliasing weighting functions for multislice helical CT

We develop a new projection weighting function for interpolation and reconstruction of multi-slice helical computed tomography data with the hope of reducing longitudinal aliasing in reconstructed volumes. The weighting function is based on the application of the Papoulis generalized sampling theorem to the interlaced longitudinal samples acquired by the multi-slice scanner. We call the approach 180MAA, for multi-slice anti-aliasing. For pitch 3, the 180MAA approach yields high-quality images of the 3D Shepp-Logan phantom as well as a longitudinal MTF superior to that of the 180MLI approach, which is based on the use of linear interpolation. However, it is not as successful at mitigating aliasing as had been doped due to the presence of a significant and unexpected aliasing component that can be attributed to the small cone angle in multi-slice helical CT. The presence of this effect is interesting and significant in its own right, however.
Ecosystem respiration and organic carbon processing in a large, tidally influenced river : the Hudson River

We estimated whole-ecosystem rates of respiration over a 40-km stretch of the tidally influenced freshwater Hudson River every 2 to 3 weeks from May through November. We measured in situ concentrations of oxygen over depth at dusk and dawn at 10 stations spaced over this interval. The use of multiple stations allowed for the consideration of the influence of tidal advection of water masses. Respiration was estimated from the decrease in oxygen overnight with a correction for diffusive exchange of oxygen with the atmosphere. We estimated this flux of oxygen to or from the atmosphere using the measured oxygen gradient and a transfer velocity model which is a function of wind velocity. Integration of the data for the period of May through November yields an estimate of whole-ecosystem respiration of 591 g C m−2 (S.E. = 66). That the standard error of this estimate is relatively low (11% of the estimate) indicates that the use of multiple stations adequately deals with error introduced through the advection of water between stations. The logarithm of average daily respiration rate was correlated with average daily temperature (p = 0.007;r 2 = 0.62). We used this temperature-respiration relationship to derive an estimate of the annual respiration rate of 755 g C m−2 yr−1 (S.E. = 72). This estimate is moderately sensitive to the estimated flux of oxygen between the atmosphere and water; using the lower and upper 95% confidence limits of our model relating the transfer velocity of oxygen to wind speed gives a range of annual respiration estimates from 665 g C m−2 yr−1 to 984 g C m−2 yr−1. The river is strongly heterotrophic, with most respiration driven by allochthonous inputs of organic matter from terrestrial ecosystems. The majority of the allochthonous inputs to the river (over 60%) are apparently metabolized within the river. Any change in allochthonous inputs due to changes in land use or climate patterns would be expected to alter the oxygen dynamics and energy flow within this tidally influenced river.
Refining indications for contemporary surgical treatment of renal cell carcinoma metastatic to the pancreas

Abstract Background The pancreas is a rare location for metastatic disease, with only 2–11% of all pancreatic tumours being of non-primary origin. It is also uncommon for renal cell carcinoma (RCC) to metastasize to the pancreas (1–3% of cases) and, when it does, it typically occurs substantially after index nephrectomy. It is not known whether all pancreatic metastases need be resected because today's chemo- and biological therapies are increasingly effective in controlling advanced disease. Methods Six patients with a variety of symptoms are discussed. Four patients presented with recurrent gastrointestinal bleeding, ranging from occult to life-threatening in severity. Results The four patients with gastrointestinal bleeding had RCC metastases that had eroded into the duodenum and were successfully controlled by palliative pancreaticoduodenectomy or completion pancreatectomy. The other two patients were treated using different chemotherapeutic or biological agents. Conclusions Renal cell carcinoma metastases to the pancreas typically occur long after index nephrectomy. Although clinical presentation is variable, palliative resection should be reserved for those who develop complications, such as upper gastrointestinal bleeding, and, in other series, obstructive jaundice. Routine debulking resections do not appear to be indicated because current biological therapies effectively and reliably control disease over long periods.
Effect of surgical removal of endometrial cups on concentrations of chorionic gonadotrophin and subsequent fertility in the mare

Seven pregnant mares underwent general anaesthesia, laparotomy, hysterotomy and removal of a 50-day conceptus. Eversion of the uterine horn through the hysterotomy site allowed direct visualisation and electrosurgical removal of endometrial cup tissue from 5 randomly selected mares (Nos 1-5), while cup tissue in 2 mares (Nos 6 and 7) was left intact. Two pregnant mares served as unoperated controls (Nos 8 and 9). Efforts to re-establish pregnancy were initiated 20 days after surgery. Serum samples collected before surgery and during the post-operative period were analysed for concentration of horse chorionic gonadotrophin (CG) by radioimmunoassay. Mean (+/- sd) weight and area of removed tissue was 9.91 +/- 4.6 g and 22.4 +/- 5.9 cm2, respectively. Concentrations of CG ranging from 3440 to 21,220 ng/ml were highest at the time of cup removal (50 days) and declined thereafter. Peak concentrations of CG at the time of surgery were not linearly correlated (r = -0.59) with mass of excised cup tissue. Individual CG half-life values for Mares 1-5 ranged from 5.4 to 8.8 days (mean 7.1 +/- 1.2 days). Peak CG concentrations occurred 68 days after conception with a rate of disappearance (half-time) of 13.4 +/- 0.4 days in Mares 6 and 7 and at 74 and 78 days after conception with a half-time of 14.0 +/- 5.7 days in Mares 8 and 9. Mares 1-5 exhibited behavioural oestrus and ovulation 30-44 days after surgery. Pregnancy occurred in 3 mares within 41 days after surgery and was associated with concentrations of CG below 200 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)
Centrally mediated hemodynamic effects of cocaine in rabbits: the role of local anesthetic actions and biogenic amine re-uptake blockade

Abstract This study sought to identify the central nervous system-mediated cardiovascular effects of cocaine and to determine if these effects result from local anesthetic actions or biogenic amine re-uptake blockade. New Zealand rabbits received multiple i.c.v. doses of cocaine, pseudococaine, lidocaine or desipramine while recording blood pressure and heart rate. Moderate dose cocaine produced a decrease in heart rate and mean arterial pressure while the highest dose produced increases in heart rate and blood pressure. Lidocaine and pseudococaine produced dose-dependent increases in blood pressure while desipramine produced decreases in heart rate and mean arterial pressure. In this model, the central nervous system-mediated cardiovascular effects of cocaine are dose-dependent; low doses produced cardiovascular depression while higher doses produced cardiovascular stimulation. The data also suggest that cocaine's local anesthetic effects are responsible for its central nervous system-mediated cardiovascular stimulation, while biogenic amine re-uptake blockade causes cardiovascular depression.
DILI: New Insights into Diagnosis and Management

Drug-induced liver injury continues to have a significant impact. With over 1000 drugs now registered as causing DILI, this form of liver injury is the most cited reason for withdrawal of a drug from the marketplace. Despite this, the diagnosis of DILI continues to rely on subjective measures and expert opinion with results that are both difficult to verify and reproduce. However, recent developments in DILI research may provide new insights to improve diagnosis and treatment in the future.
Hippopotamus Underwater Locomotion: Reduced-Gravity Movements for a Massive Mammal

Use of the aquatic environment by hippopotami (Hippopotamus amphibius) allows locomotive styles impossible to achieve on land by such heavy animals. Videos of the underwater locomotion of 2 hippopotami were analyzed frame by frame. Average horizontal velocity underwater was 0.47 m/s. Hippopotami used a gait underwater that was similar to a gallop with extended unsupported intervals. Ground contact time decreased with increasing horizontal velocity, vertical displacement during the unsupported intervals increased with an increase in ground contact time, and time between consecutive footfalls decreased with an increase in horizontal velocity. Hippopotami use an unstable gait underwater, which is facilitated by the increased buoyancy of water. Despite restrictions to movement on land due to its massive weight, locomotion of the hippopotamus underwater is analogous to movement in a microgravity environment.
Phylogeography of Sea Oats (Uniola paniculata), a Dune-building Coastal Grass in Southeastern North America

We tested the hypothesis that Uniola paniculata populations are divided into eastern and western lineages, with the primary geographic break at the southern tip of Florida, as observed in codistributed animal taxa. We asked whether the geographic distribution of chloroplast DNA (cpDNA) variation in U. paniculata corresponds to 1) genetic structure in nuclear variation reported in previous studies, and 2) the geographic distribution of morphological adaptive traits reported in previous studies. We sampled 66 populations and performed phylogeographic analyses using sequence variations in maternally inherited cpDNA. We reconstructed the intraspecific phylogenetic network with TCS software and identified phylogeographic breaks in the species using Monmonier’s algorithm. Analyses identified 6 cpDNA haplotypes and 2 major lineages: eastern (Atlantic) and western (Gulf), with a phylogeographic break at the southern tip of Florida. The data suggest U. paniculata survived the last glacial maximum (LGM) in southern refugia. Following the LGM, differential leading-edge recolonization explains the current distribution of haplotypes into 2 lineages. Populations containing a haplotype from outside its native range are likely due to human-mediated transplantation. The genetic structure of cpDNA variation has weak correlation with nuclear DNA variation, and there is partial concordance between the geographic distribution of cpDNA and morphological variation.
Assessment of the Delayed Neurotoxicity of Tributyl Phosphate, Tributoxyethyl Phosphate, and Dibutylphenyl Phosphate:

There industrial organophosphorus compounds were tested for their ability to cause organophosphorus compound-induced delayed neurotoxicity (OPIDN) in the adult hen. The compounds tested were tribut...
Optimization techniques for concurrent STM-based implementations: A concurrent binary heap as a case study

Much research has been done in the area of software transactional memory (STM) as a new programming paradigm to help ease the implementation of parallel applications. While most research has been invested for answering the question of how STM should be implemented, there is less work about how to use STM efficiently. This paper is focused on the challenge of how to use STM for efficient and scalable implementations of non-trivial applications. We present a fine-grained STM-based concurrent binary heap, an application of STM for a data structure that is notoriously difficult to parallelize. We describe extensions to the basic STM approach and also the benefits of our proposal. Our results show that the fine-grained STM-based binary heap provides very good scalability compared to the naive approach. Nevertheless, we reach a point where the complexity of some fine-grained techniques do not justify its use for the increase in performance that can be obtained.