cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal Models Beneath Kamchatka and the Pacific Plate Rejuvenation from a Mantle Plume Impact

The Northwest Pacific area, comprising the Kamchatka peninsula, is a distinctive area where a series of on going geodynamical processes like: plate rejuvenation from a mantle plume impact, slab detachment, slab edge melting and exotic volcanism, take place. With the help of finite element modeling we infer the thermal structure across Kamchatka in a series of 2D profiles normal to the trench. We chose the location at these profiles based on seismicity, geochemical variation and offshore heat flow measurements. Assuming that the transition from brittle to ductile behavior inside the subducting slab corresponds to the 650°C isotherm, our thermal models predict a good fit with maximum depth of seismicity (∼500 km) for southern Kamchatka only if the exothermic olivine-spinel phase transition is introduced. In the central part of Kamchatka, a good fit is obtained if the hot mantle plume, located just beneath Meiji Guyot seamount, thermally rejuvenates the subducting Pacific plate. Further to the north, the seismicity shallows more (200-100 km) and slab rejuvenation alone cannot provide a thermal structure with a good fit with seismically active subducting slab. A good explanation for such shallow seismicity might be the slab detachment due to cessation of subduction just north of Kamchatka-Aleutians junction. The thermal structure beneath the northernmost active volcano in Kamchatka, Scheveluch, which exhibits a strong adakitic signature, shows that slab edge exposure to the hotter asthenosphere creates the favorable conditions for oceanic crust melting at ∼70 km depth, just beneath Scheveluch. Our numerical models show that plate rejuvenation from a mantle plume, slab edge exposure to hot upper mantle and probably slab detachment play an essential role in subduction slabs thermal structure, seismicity down-dip extension and geochemical variations of lavas in Kamchatka.
Characterizations of PUNC and precomputation

Much complexity-theoretic work on parallelism has focused on the class NC, which is defined in terms of logspace-uniform circuits. Yet P-uniform circuit complexity is in some ways a more natural setting for studying feasible parallelism. In this paper, P-uniform NC (PUNC) is characterized in terms of space-bounded AuxPDA's and alternating Turing Machines with bounded access to the input. We also present a general-purpose parallel computer for PUNC; this characterization leads to an easy proof that NC = PUNC iff all tally languages in P are in NC. The characterizations of PUNC lead to natural methods for modelling precomputation. We show that for many classes of interest, there is a single “universal” table which can be used in place of any table of similar size and complexity, while for certain other classes, no such “universal” table exists.
New Technique to Produce a Cotton/Polyester Blend Yarn with Improved Strength

This paper describes a newly developed, relatively simple but effective technique of producing a novel pseudo-composite cotton-rich staple blend yarn with improved tensile properties. The spacing between cotton and polyester rovings drafted simultaneously on a ring-spinning frame affects yarn structure, resulting in significantly stronger yarns than those produced by drafting the same two rovings together. The new composite or combination yarns may be useful in developing relatively stronger cotton-rich materials suitable for a variety of finishes and end uses.
Czech Archives at the Crossroads: Breaking with the Past

The close ties of the Czechoslovak archival institutions with the ideological superstructure of the past oppressive Communist regime has left the archives vulnerable to attacks in the period of ideological breakdown of Marxism-Leninism throughout the Eastern bloc countries. The future of Czech and Slovak archives will be determined by how fast and thoroughly they disassociate themselves from the untenable ideology and from their own inconvenient past. The major task for archivists today is to rehabilitate, to reform, and to integrate the archival profession into the new social order. The first steps in the right direction have been taken. How Czechoslovak archivistics will meet the challenge of newly regained autonomy under the conditions of Czechoslovakia's strangled economy remains to be seen.
Muscarinic agonists activate an inwardly rectifying potassium conductance in medial pontine reticular formation neurons of the rat in vitro

Intracellular recordings were obtained from neurons in pontine reticular formation slices of the rat to characterize a cholinergic-gated increase in conductance. The conductance increase was associated with a hyperpolarization of the membrane potential and with an outward current under voltage-clamp conditions. Current-voltage relations and potassium substitution experiments indicated mediation by a change in permeability, primarily to potassium. This potassium conductance exhibited inward rectification at membrane potentials negative to resting potential, a novel finding for cholinergic actions in CNS neurons. Further characterization of this inwardly rectifying potassium conductance revealed marked sensitivity to low concentrations of barium. Cholinergically evoked currents were relatively unaffected by the presence of extracellular cesium. Cholinergic effects persisted in TTX. The outward currents elicited by carbachol or methacholine were blocked only by high concentrations of pirenzepine, a selective antagonist of the M1 muscarinic receptor. The interaction between these agents is quantitatively consistent with cholinergic action at postsynaptic muscarinic receptors of the non-M1 subtype.
Corridor Variance Swap

A corridor variance swap with corridor C is a weighted variance swap, with weight given by the indicator of C. We discuss the corridor variance swap's motivations, model-free replication and valuation, relation to local time, valuation via characteristic function, and issues of discretization. Keywords: corridor variance swap; up variance; down variance; model-free replication; pricing; characteristic function; local time; discretization
Vicarious and operant experiences in the etiology of illness behavior: a replication with healthy individuals.

Abstract The purpose of the present investigation was to replicate a previous study of diabetic patients on the role of parental modeling in the etiology of illness behavior. A random sample of healthy individuals were assigned to an avoidant model (AM) (i.e. parent reported to have avoided work. chores etc. when ill) or non-avoidant model (NAM) group. Subjects subsequently provided retrospective and current information concerning their illness-behavior experiences. The results indicated that individuals with an AM reported more responsibility avoidance when ill currently and as a child compared to the NAM subjects. Additionally. AM subjects reported receiving more positive reinforcement for current illness compared to NAM subjects. It was concluded that the process by which individuals learn to respond to illness may be similar in healthy and chronically-ill individuals but that positive reinforcement for illness may be more likely to be received by healthy individuals during acute illness than by chronically-ill individuals. The present study provides further preliminary support for the learningtheory model of illness behavior.
Atherogenic Lipids and Lipoproteins in Hemodialysis Patients

Dyslipidemia may contribute to atherosclerosis in hemodialysis patients. While hypertriglyceridemia is relatively common in this population, hypercholesterolemia is not. Since abnormalities in various plasma cholesterol fractions and lipoproteins have been associated with an increased incidence of cardiovascular disease in the nonuremic population, we examined these abnormalities to determine whether they occur in patients with chronic renal failure. Twenty-four patients on maintenance hemodialysis were studied. We found that, despite relatively low plasma total cholesterol levels, a substantial number of patients had low high-density lipoprotein cholesterol, low apolipoprotein AI, and high apolipoprotein B levels. Furthermore, approximately 40% and 30%, respectively, of the patients had elevated plasma levels of lipoprotein(a) and remnants of chylomicron and very low-density lipoprotein. Lipoprotein(a) levels could not be predicted from any of the variables that were studied. The abnormal plasma levels of these potentially atherogenic lipids and lipoproteins suggest that they may contribute to the high incidence of cardiovascular diseases in the hemodialysis population.
Improving data collection and monitoring through real-time data analysis

Feedback based on real-time data is increasingly important for ICT-based interventions in the developing world. Applications such as facility inventories, summarization of patient data from community health workers, etc. need processes for analyzing and aggregating datasets that update over time. In order to facilitate such processes, we have created a modular web service for real-time data analysis: bamboo.
Link Layer Packet Loss Classification for Link Adaptation in WLAN

Voice over IP (VoIP) and high quality video streaming becomes an alternative to conventional telephony and TV service in many locations by way of ongoing deployment of WLAN hotspots. The newly proved IEEE 802.11e QoS enhancement standard will be a proper solution of delay demanding for real-time multimedia applications, while the existing auto rate fallback (ARF) link adaptation scheme, designed to improve wireless transmission by dynamically selecting transmission rates and frame sizes, cannot effectively solve the QoS concerns of multimedia communication due to the growing UDP traffic. In this paper, we presented comprehensive analyses of link layer behavior to infer the cause of packet loss in a WLAN. More specifically, we classify the packet loss into either congestion or wireless errors based mainly on delays and MAC layer parameters under congestion and/or link error dominated status. A link layer packet loss classification scheme can thus be proposed to support link adaptation for VoIP applications in WLAN.
Formation of (±)-forskolin via a cuprate addition to a synthetic dihydropyran-4-one

Abstract The racemic, synthetic dihydropyran-4-one 2d was converted to (±)-forskolin 1 in several steps.
Modelling effects of forest canopies on slope stability

We investigated the potential effects of rainfall intensity smoothing by forest canopies on slope stability by modelling soil responses to measured rainfall and throughfall during high-intensity rain. Field measurements showed that maximum intensities of precipitation were generally reduced under forest canopies at two sites in the Pacific Northwest, USA. Modelling soil water pore-pressure responses of a hypothetical hillslope to the field data resulted in estimates of slope stability that were generally greater under forest canopy than for the same hillslope without forest canopy. Results indicate that smoothing of precipitation intensities may translate into overall greater stability of hillslopes under forest canopies. Copyright © 2003 John Wiley & Sons, Ltd.
Distributions of dissolved organic and inorganic carbon and radiocarbon in the eastern North Pacific continental margin

Abstract Temporal variations in the natural radiocarbon ( 14 C) signatures of dissolved organic and inorganic carbon (DOC and DIC, respectively) in seawater have been studied previously (Druffel, E.R.M., Bauer, J.E., Williams, P.M., Griffin, S., Wolgast, D.M., 1996. Seasonal variability of radiocarbon in particulate organic carbon in the northeast Pacific. J. Geophys. Res. 101, 20 543–20 552; Bauer, J.E., Druffel, E.R.M., Williams, P.M., Wolgast, D.M., Griffin, S., 1998. Temporal variability in dissolved organic carbon and radiocarbon in the eastern North Pacific Ocean. J. Geophys. Res. 103, 2867–2882) at a long-term time-series station (Sta. M: 32°N, 123W) in the eastern North Pacific located at the eastern edge of the North Pacific abyssal plain. In June 1995 a transect was made from Sta. M inshore to approximately 500 m depth in order to evaluate the distributions of 14 C in DOC and DIC from the abyssal plain to the upper continental slope. Concentrations and Δ 14 C values of DOC in mixed layer waters (25 and 85 m) decreased toward the upper slope. In deeper waters, concentrations and Δ 14 C values were in general similar at all three sites. Differences in DOC concentrations and Δ 14 C-DOC between Sta. M and the rise and upper slope sites were explained in part by the mixing of DOC and Δ 14 C along constant density ( σ t ) surfaces. However, specific deviations from conservative behavior due to mixing were observed for Δ 14 C-DOC at mesopelagic (∼700 m) and near-bottom (∼3600– 3900 m) depths of the continental rise. Comparable findings are reported for DIC, where σ t -normalized concentrations and Δ 14 C values in Sta. M, rise and upper slope waters were similar, with the exception of slight increases in concentrations and Δ 14 C values in near-bottom waters of the rise. These observations indicate that both DOC and DIC in continental rise and slope surface waters of the eastern North Pacific Ocean margin are comprised of a component of actively upwelled material derived from deeper offshore waters and a component of recent surface-derived material. Our data suggest that contributions of both 14 C-enriched and 14 C-depleted DOC and DIC to localized regions of the water column occur in waters of the continental rise and slope. The sources of material having anomalous Δ 14 C values are not certain, but may include organic matter derived from off-shelf and slope transport, particulate organic carbon solubilization, and sediment porewaters. We also examine the relationships between Δ 14 C-DOC and both Δ 14 C-DIC and Δ 14 C of suspended POC measured in a companion study as a means of evaluating similarities or differences in the mechanisms responsible for the distributions of each at all three sites.
Beyond the Wage Premium: Fatherhood and Asset Accumulation

This study examines the association between becoming a father and men's asset accumulation trajectories. It is the first study to include nonmarried fathers in addition to married fathers. We used data from the National Longitudinal Survey of Youth, 1979 cohort (the 1979 and 1985–2000 wave) and multilevel modeling techniques to examine the research questions. Findings revealed that the association between fatherhood and men's total asset accumulation depended on marriage. Upon becoming fathers, married men increased their rates of asset accumulation. By way of contrast, unmarried men who became fathers had a decline in their rate of asset accumulation, on average. Race also moderated the association between fatherhood and asset accumulation.
Differential Effect of Chronic Nicotine Administration on Brain Cytochrome P4501A1/2 and P4502E1

The effects of chronic nicotine administration on the enzymatic activities and immunoreactivities of P4501A1/2 and P4502E1 were determined in microsomal fractions from brain regions and liver. Chronic nicotine increased 7-ethoxyresorufin O-deethylase activity and P4501A1/2 immunoreactivity in hippocampus and brain stem, decreased values in cerebral cortex, thalamus, and striatum, and did not affect parameters in other brain regions. In contrast, N-nitrosodimethylamine N-demethylase activity from nicotine-injected rats increased in all brain regions examined, and this increase was associated with increased P4502E1 immunoreactivity. Chronic nicotine did not alter either enzyme activities or immunoreactivities of these isoforms in hepatic microsomes.
Sirolimus affects cardiomyocytes to reduce left ventricular mass in heart transplant recipients.

The cellular mechanisms underlying cardiac hypertrophy may result from changes in cardiac myocyte growth and differentiation. We tested whether sirolimus, an immunosuppressive agent that inhibits mTOR, a protein that regu- lates cell division and differentiation, might modify cardiac hypertrophy after cardiac transplantation. Methods and results Fifty-eight cardiac transplant recipients were withdrawn from treatment with calcineurin inhibitors (CNIs) and treated with sirolimus. Eighty-three control subjects were maintained on CNIs. After 12 months, left ventricular (LV) mass decreased from 196.15+48.28 to 182.21+43.56 g (P ¼ 0.05) and LV mass index from 99.25+20.08 to 93.82+20.22 g/m 2 (P ¼ 0.031) in sirolimus-treated subjects but did not change in controls. The left atrial volume index of sirolimus-treated subjects decreased from 52.44+17.22 to 48.40+15.14 cc/m 2 (P ¼ 0.008) and increased from 52.07+19.45 to 57.03+19.93 cc/m 2 (P ¼ 0.0012) in controls. The difference between the groups was independent of blood pressure. The number of cells in myocardial biopsies positive for p27Kip1, a protein induced by mTOR inhibition, increased in sirolimus-treated subjects (P ¼ 0.0005) and did not change in con- trols (P ¼ 0.54) suggesting sirolimus acted directly on myocardium. Conclusion Sirolimus may inhibit adverse ventricular remodelling resulting in cardiac hypertrophy and have potential in the treat-
TU‐D‐AUD B‐02: Volumatric Modulated Arc Therapy: Implementation and Evaluation for Prostate Cancer Cases

Purpose: Volumetric modulated arc therapy (VMAT) (Otto K, Medical Physics, 2008) is an emerging treatment paradigm which modulates MLC aperture and dose rate during gantry rotation. The purpose of this study is to implement and evaluate VMAT relative to the standard IMRT approach. Method and Materials: A gantry rotation up to 360° is modeled as 360 evenly divided beams. Beam apertures and dose rate are optimized with respect to gantry angles under a DVH constraints based objective. Differences between our VMAT implementation and previous VMAT are: using gradient search for dose rate optimization rather than random search, and sampling multiple MLC leaf positions within the allowed leaf speed constraints rather than a single one in each iteration. A planning study including 5 prostate patients with a prescription dose of 86.4Gy was performed to evaluate VMAT verse the standard 5‐field IMRT approach. VMAT treatment plans are normalized such that certain critical organ dose limits are met, and are comparable to IMRT plans. V95, D95 and mean dose of PTV are used to evaluate plans, while monitor unit (MU) and delivery time are used to assess delivery efficiency. Results: The PTV V95, D95 and mean dose in VMAT plans are 97.0±0.8%, 96.4±0.5%, and 101.7±0.4%, respectively, vs 97.1±0.8%, 97.5±1.0% and 103.0±0.7% in IMRT plans. VMAT and IMRT plans are indistinguishable measured by these dose indices. The advantage that VMAT presents is it reduces MU by 49.8±7.4%. Secondary scatter dose to patient is reduced accordingly. A typical prostate treatment is shortened from about 5 minutes for IMRT to 2.6±0.2 minutes for VMAT. The better delivery efficiency of VMAT is accomplished by having a larger time averaged beam aperture: 49.1±5.2cm2 vs 19.5±1.5 cm2 in IMRT.Conclusion: VMAT technique can reduce treatment time by up to 50% while maintaining comparable dosimetric quality to standard IMRT approach.
Sedimentary and historical context of eutrophication and remediation in urban Lake McCarrons (Roseville, Minnesota)

Abstract Geochemical analysis of the varved (annually laminated) sediments of a small, deep urban lake in east-central Minnesota shows that some water-quality and watershed indicators are approaching prehistoric (pre-1850s) values after an excursion to anomalous levels during the 1920s through 1950s. This high-resolution paleolimnological information (annually resolved for most of the 20th century), including varve thickness measurements on a digital image, carbon stable isotopic composition of organic matter, and sedimentary component quantification, provides historical perspective to lake managers planning remedial measures with reference to the “natural” state of the lake, especially in regard to the perception that water quality has declined only in recent decades (i.e., in the late 20th century). The lake is at present eutrophic and oligomictic, with oxygen-depleted bottom waters enriched in dissolved solids relative to surface waters; an alum treatment has contributed to the problem of persistent st...
Why Peasant Farmers Borrow

Interest rates are high in the rural credit markets of poor countries. Yet it is often said that the rates of return on capital invested in traditional inputs is low. Under these conditions it would seem uneconomic for farmers to borrow; if funds are needed, farmers should sell assets. If the expected costs are greater than the expected benefits, farmers will not have as much incentive to borrow money. Indeed, the evidence suggests that in poor countries most farmers are free of debt. But there is great diversity; some farmers do have high marginal returns on capital; some borrow at low rates; seasonality influences the debt structure, as does the level of wealth; and transactions costs may make borrowing cheaper than selling assets. Introducing uncertainty reduces the chances that farmers will borrow.
Polyimide neural probe for chronic sensing of neural activity and micro-positioning

The goal of this research is to develop a mechanically flexible and biocompatible neural probe for in-vivo monitoring of unit neural impulses in the brain. In this research we present an implantable flexible polyimide-based neural probe that can minimize mechanical impact into the brain. Our device also features a micro-drive device which allows us to vertically adjust the probe after surgical implantation. This presentation will present the design and fabrication methods of a flexible polyimide probe and a microdrive.
Teaching Physiological Psychology versus Teaching Biological Psychology: Is There a Difference?:

Some authors recommend that biological psychology replace physiological psychology. College catalogs from 539 undergraduate programs were examined to determine the percentage of colleges that offer courses in physiological psychology, biological psychology, both, or neither. Physiological psychology is still offered in 64.1% of the institutions studied, and biological psychology is taught in 11.3%. However, college catalog descriptions revealed considerable confusion over the difference between the two terms.
Evidence for a Phe-Gly-Leu-amide-like allatostatin in the beetle Tenebrio molitor.

The allatostatins (ASTs) with Phe-Gly-Leu-amide C-terminal sequence are multifunctional neuropeptides discovered as inhibitors of juvenile hormone (JH) synthesis by corpora allata (CA) of cockroaches. Although these ASTs inhibit JH synthesis only in cockroaches, crickets, termites and locusts, isolation of peptides or of cDNA/genomic DNA or analysis of genomes indicates their occurrence in many orders of insects with the exception of coleopterans. The gene for these ASTs has not been found in the genome of the red flour beetle Tribolium castaneum (Family Tenebrionidae). Yet, in view of widespread occurrence of these peptides in insects, crustaceans and nematodes, they would be expected to occur in beetles. This study provides evidence for the presence of FGLa-like ASTs in the tenebrionid beetle, Tenebrio molitor, and scarabid beetle, Popillia japonica. Extract of brain from both beetles inhibited JH synthesis by cockroach CA dose dependently and reversibly. 20 brain equivalents of T. molitor and P. japonica extracts inhibited JH synthesis 64 ± 5 and 65 ± 0.6% respectively. Antibody against cockroach allatostatin (Diploptera punctata AST-7) used in an enzyme-linked immunosorbent assay reacted with brain extract of these beetles. Antibody against D. punctata AST-5 localized FGLa-like ASTs in the brain and subesophageal ganglion of T. molitor and P. japonica. In addition, pretreatment of T. molitor brain extract with anti-D. punctata AST-5 reduced the inhibition of JH synthesis and pretreatment of anti-D. punctata AST-5 with D. punctata AST-5 diminished the immunoreactivity of the antibody. Thus we predict that FGLa-like allatostatins will be found in beetles.
Teacher Preparation, Professional Development, and Long-Term English Learners

This article presents a synthesis of research linking Long-Term English Learners (LTELs) and the underprepared schools and teachers they have encountered. The purpose of this article, though small in scope, is to explore the policies, practices, and conditions surrounding teacher preparation and professional development in relation to the growing number of LTELs. While the standards designed to guide curriculum have paid little attention to second-language development and differ only slightly from those designed for native English speakers, the number of LTELs in the United States has continued to rise therefore causing the factors which impact the failure of English Learners (ELs) to achieve reclassification as English Proficient students to become an issue of focus in education. Multi-cultural theorists have argued that diversity issues are central to the rest of the curriculum and must be infused throughout courses, field experience requirements, and professional development in order to strengthen preservice and inservice teachers’ multi-cultural relational capacity and knowledge of instructional strategies for ELs and LTELs. While other nations have taken the initiative to produce highly effective, experienced, and dedicated teachers there remains a desperate need for a general consensus to build a policy infrastructure that supports reform with the intention of preventing future harm to the diverse student population in the U.S.
Optical linear discriminant functions

The use of computer generated holograms to implement feature extraction operations has been achieved. The optical realization and use of multiple linear discriminant functions on a high-dimensionality feature space for large class pattern recognition is described and initial experimental results are provided.
Structure of attached and lifted gas jet flames in hysteresis region

The flame structure and hysteresis chacracteristics of lifting and reattaching propane jet flames over contoured nozzles were studied. High-speed schlieren photography was employed to investigate the flow field in the near-nozzle region of cold jets, attached flames, lifted flames, and their transitions. Fine-wire thermocouples were used in conjunction with a computer data acquisition system to record temperature field in the stabilization region. Gas sampling and analysis were employed to determine the mean concentrations of oxygen and carbon monoxide The mean velocities were determined with a total pressure tube. The flow in the flame stabilization region is observed to be laminar in attached flames and dominated by organized structures in lifted flames. The characteristics of those structures have been measured during liftoff and reattachment transitions and compared with cold jet data. The average dimensionless celerities and Strouhal numbers of the organized structures in the burning parts of the flames were measured as 0.94 and 2.8 during liftoff and 0.62 and 1.30 during reattachment, respectively. The schlieren photographs and radial profiles of temperature and concentrations establish that the flame zone is located away from the shear layer. Further, they show that the molecular diffusion controls the lifting process. The dynamics of the organized structures that result in a wider shear layer govern the reattachment process. This difference between the structures of the flame base in the two configurations accounts for the hysteresis phenomenon. The variations of liftoff and reattachment velocities with nozzle diameter, fuel molecular weight and addition of inert diluents to the jet fluid were measured to substantiate these observations.
Limits on Surface Vicinality and Growth Rate due to Hollow Dislocation Cores on KDP { 101 }

Atomic-force microscopy measurements on KDP ${101}$ faces are presented which show that the terrace width $W$ on vicinal dislocation growth hillocks is nearly independent of supersaturation \ensuremath{\sigma} and Burgers vector $b$, in contradiction to simple Burton-Cabrera-Frank models. An analytical model taking into account the effect of dislocation cores on step rotation is presented which predicts a dependence of $W$ on \ensuremath{\sigma} and $b$, in good agreement with the measurements. Using these results, we rescale macroscopic growth rate data onto a single Arrhenius curve, which gives a value of 0.33 eV for the activation energy of step motion.
Personalism and moral leadership: the servant leader with a transforming vision

After briefly describing the philosophy of personalism this article assesses each of three normative leadership paradigms (transformational leadership, postmodern or postindustrial leadership, and servant leadership) in terms of five major themes of this phenomenological philosophy. Servant leadership appears to be closest to personalism. The critical ingredient for servant leadership is also personalism’s starting point, i.e. the dignity of each human person. A genuine servant leader works with his followers in building a community of participation and solidarity. However, some claim that servant leaders are subject to manipulation by their followers. If so, and if transformational leaders, when too successful, gain too much power or manipulate using bogus empowerment, a superior approach might be provided by a combination in which a morally tough servant leader adopts certain transforming behaviors of Bass’s altruistic transformational leader. The leader and the followers would focus on a jointly formulated and refined vision, avoiding manipulation by any party through a mutual commitment to participation, solidarity of community, and respect for each person.
Fourier Transform Infrared Analysis of Purified Lactose Permease: A Monodisperse Lactose Permease Preparation Is Stably Folded, α-Helical, and Highly Accessible to Deuterium Exchange†

The lactose permease, encoded by the lacY gene of Escherichia coli, is an integral membrane protein that functions as a proton and lactose symporter. In this study, we have characterized a novel monodisperse, purified preparation of lactose permease, as well as functionally reconstituted lactose permease, using spectroscopic techniques. The purification of monodisperse lactose permease has been aided by the development of a lacY gene product containing an amino-terminal six histidine affinity tag. In the novel purification method described here, lactose permease is purified from beta-dodecyl maltoside-solubilized membrane vesicles using three sequential column steps: hydroxyapatite, nickel-nitriloacetic acid (Ni-NTA) affinity, and cation-exchange chromatography. The hydroxyapatite step was shown to be essential in reducing aggregation of the final purified protein. Amino acid composition analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis support the conclusion that the protein has been purified to greater than 90% homogeneity. The protein has been successfully reconstituted and has been shown to be active for lactose transport. Fourier transform infrared (FT-IR) spectroscopy has been performed on monodisperse lactose permease and on proteoliposomes containing functional lactose permease. FT-IR spectroscopy supports the conclusion that the monodisperse lactose permease preparation is 80% alpha-helical and stably folded at 20 degreesC; thermal denaturation is first detected at 70 degreesC. Because the purified protein is also readily susceptible to 2H exchange, these results suggest that the protein is conformationally flexible and that 2H exchange is facilitated as the result of conformational fluctuations from the folded state.
Normative Discrimination and the Motherhood Penalty

This research proposes and tests a new theoretical mechanism to account for a portion of the motherhood penalty in wages and related labor market outcomes. At least a portion of this penalty is attributable to discrimination based on the assumption that mothers are less competent and committed than other types of workers. But what happens when mothers definitively prove their competence and commitment? In this study, we examine whether mothers face discrimination in labor-market-type evaluations even when they provide indisputable evidence that they are competent and committed to paid work. We test the hypothesis that evaluators discriminate against highly successful mothers by viewing them as less warm, less likable, and more interpersonally hostile than otherwise similar workers who are not mothers. The results support this “normative discrimination” hypothesis for female but not male evaluators. The findings have important implications for understanding the nature and persistence of discrimination towa...
A TEST OF A RISK-ADJUSTED DIVIDEND CAPITALIZATION MODEL: THE CASE OF LIQUIDATING FIRMS

In this paper a direct test of the descriptive validity of the dividend capitalization model is described using the capital asset pricing model (CAPM) to specify the required rate of return. The sample comprises thirty-five voluntarily liquidating firms for which publicly available records of liquidating dividends are available. The sample provides a novel basis for testing the dividend capitalization model since: (1) the firms' risk does not change because of investment activity, (2) the decision horizon for stock valuation purposes is clearly the period over which cash dividends are paid to shareholders, and (3) it is unnecessary to estimate dividend growth rates or terminal stock values. Results are generally consistent with a market that values these stocks by applying a risk-adjusted dividend capitalization model.
Scheduling of independent jobs in star graph networks

Abstract In this paper, we investigate the problem of how to schedule n independent jobs on an m -dimensional star graph based network. We develop a feasibility algorithm for preemptively scheduling a given set of jobs with dimension and time requirements on a star graph network of given size with a given deadline. We show that the algorithm runs in O ( n log n ) time where n is the number of jobs. We also develop a simple heuristic for nonpreemptive scheduling of jobs and study its lower and upper bounds.
Cloning and characterization of a mammalian prenyl protein-specific protease.

Abstract Proteins containing C-terminal “CAAX” sequence motifs undergo three sequential post-translational processing steps: modification of the cysteine with either a 15-carbon farnesyl or 20-carbon geranylgeranyl isoprenyl lipid, proteolysis of the C-terminal -AAX tripeptide, and methylation of the carboxyl group of the now C-terminal prenylcysteine. A putative prenyl protein protease in yeast, designated Rce1p, was recently identified. In this study, a portion of a putative human homologue of RCE1 (hRCE1) was identified in a human expressed sequence tag data base, and the corresponding cDNA was cloned. Expression of hRCE1 was detected in all tissues examined. Both yeast and human RCE1 proteins were produced in Sf9 insect cells by infection with a recombinant baculovirus; membrane preparations derived from the infected Sf9 cells exhibited a high level of prenyl protease activity. Recombinant hRCE1 so produced recognized both farnesylated and geranylgeranylated proteins as substrates, including farnesyl-Ki-Ras, farnesyl-N-Ras, farnesyl-Ha-Ras, and the farnesylated heterotrimeric G protein Gγ1 subunit, as well as geranylgeranyl-Ki-Ras and geranylgeranyl-Rap1b. The protease activity of hRCE1 activity was specific for prenylated proteins, because unprenylated peptides did not compete for enzyme activity. hRCE1 activity was also exquisitely sensitive to a prenyl peptide analogue that had been previously described as a potent inhibitor of the prenyl protease activity in mammalian tissues. These data indicate that both the yeast and the human RCE1 gene products are bona fide prenyl protein proteases and suggest that they play a major role in the processing of CAAX-type prenylated proteins.
Ir deposition by surface combustion of (MeCp)Ir(COD): An experimental simulation of metallorganic chemical vapor deposition

Abstract The decomposition of (5-methylcyclopentadienyl)(1,5-cyclooctadiene) iridium, (MeCp)Ir(COD), has been studied on an O-covered Rh surface by isothermal and temperature-programmed desorption and isothermal reaction spectroscopy using time-of-flight mass spectrometry, and by Auger electron spectroscopy. After dosing at 100 K, monolayer molecularly adsorbed (MeCp)Ir(COD) desorbs at 325 K competing with decomposition to form adsorbed MeCp and COD. We infer that these react with adsorbed oxygen to form O-containing organic surface-bound fragments that decompose to desorb only CO 2 , CO and H 2 O since no other O-containing products were detected in the 3D spectra. While dosing both (MeCp)Ir(COD) and O 2 , pure Ir film growth occurs above 500 K provided there is a large excess of O 2 . When dosing these two reactants at 450 K, O, C, H and Ir all accumulate to give a slowly growing film that slowly evolves CO but negligible H 2 , H 2 O or CO 2 .
Electric Field Model of Transcranial Electric Stimulation in Nonhuman Primates: Correspondence to Individual Motor Threshold

Objective: To develop a pipeline for realistic head models of nonhuman primates (NHPs) for simulations of noninvasive brain stimulation, and use these models together with empirical threshold measurements to demonstrate that the models capture individual anatomical variability. Methods: Based on structural MRI data, we created models of the electric field (E-field) induced by right unilateral (RUL) electroconvulsive therapy (ECT) in four rhesus macaques. Individual motor threshold (MT) was measured with transcranial electric stimulation (TES) administered through the RUL electrodes in the same subjects. Results: The interindividual anatomical differences resulted in 57% variation in median E-field strength in the brain at fixed stimulus current amplitude. Individualization of the stimulus current by MT reduced the E-field variation in the target motor area by 27%. There was significant correlation between the measured MT and the ratio of simulated electrode current and E-field strength ( $r^{2} = 0.95$ , $p = 0.026$ ). Exploratory analysis revealed significant correlations of this ratio with anatomical parameters including of the superior electrode-to-cortex distance, vertex-to-cortex distance, and brain volume ( $r^{2} > 0.96$ , $p ). The neural activation threshold was estimated to be $0.45 \pm 0.07$ V/cm for 0.2-ms stimulus pulse width. Conclusion: These results suggest that our individual-specific NHP E-field models appropriately capture individual anatomical variability relevant to the dosing of TES/ECT. These findings are exploratory due to the small number of subjects. Significance: This study can contribute insight in NHP studies of ECT and other brain stimulation interventions, help link the results to clinical studies, and ultimately lead to more rational brain stimulation dosing paradigms.
Dysregulation of Frizzled 6 is a critical component of B-cell leukemogenesis in a mouse model of chronic lymphocytic leukemia

Wnt/Fzd signaling is known to play a key role in development, tissue-specific stem-cell maintenance, and tumorigenesis, particularly through the canonical pathway involving stabilization of β-catenin. We have previously shown that Fzd9−/− mice have a deficiency in pre-B cells at a stage when self-renewing division is occurring in preference to further differentiation, before light chain immunoglobulin recombination. To determine whether pathologic usurpation of this pathway plays a role in B-cell leukemogenesis, we examined the expression of Wnt/Fzd pathway genes in the Eμ-TCL1 mouse model of chronic lymphocytic leukemia. We find that, in the course of leukemogenesis, the expression of Wnt16, Wnt10α, Fzd1, and most dramatically, Fzd6, is progressively up-regulated in the transformed CD5+ B cells of these mice, as are β-catenin protein levels. Elimination of Fzd6 expression by crossing into Fzd6−/− mice significantly delays development of chronic lymphocytic leukemia in this model. Our findings suggest that the self-renewal signals mediated by Wnt/Fzd that are enlisted during B-cell development may be pathologically reactivated in the neoplastic transformation of mature B cells.
Mechanical function of facet joints in the lumbar spine

Sections of human cadaver lumbar spines consisting of the L3, L4 and L5 vertebrae and the intervening discs and ligaments were tested mechanically to determine the effects of simulated spondylolysis and of facet joint fusion. Compression, flexion and extension, lateral bending, axial rotation forces and torques were applied to intact specimens and then after unilateral and bilateral division of the pars interarticularis, and, in a separate group of specimens, after unilateral and bilateral immobilization of the facet joints. Division of the pars interarticularis caused a large increase in axial rotation, and a lesser increase in lateral bending. Other motions were not statistically significantly changed. Facet fixation caused a statistically significant decrease in flexion and extension only. The average anterior or posterior shear motion across the intervertebral discs was less than 1 mm in magnitude in intact specimens, and none of the interventions produced statistically significant changes in this motion accompanying the angular motion.
Comparative studies with Tribolium (Coleoptera, Tenebrionidae) — II: Productivity of T. castaneum (herbst) and T. confusum Duv. on natural, semi-synthetic and synthetic diets

Abstract Productivity of T. castaneum and T. confusum has been determined in the following diets: Naylor's synthetic medium; corn supplemented with the amino acids cystine, glutathione, proline and tryptophan in amounts necessary to bring them to the level found in wheat; corn and whole wheat flour without any supplements, and corn and whole wheat flour supplemented with brewer's yeast and vitamins. Relative developmental rates of the two species in these media were also determined by counting the numbers of adults emerging in 14-day periods. Significant differences in productivity (the number of eggs surviving to the adult stage) have been detected within a species in the different media and between species within a given medium. The Naylor medium is unfavorable for both species, and judging from relative developmental rates less favorable to T. confusum than to T. castaneum. T. castaneum performs poorest in non-supplemented media, better in media supplemented with vitamins, and the best in media supplemented with yeast. While T. confusum also shows an increased productivity in vitamin- and yeast-supplemented media, this increase is not as marked as in T. castaneum. Considering both the productivity and the developmental rates, it appears that the addition of the four amino acids to corn had a beneficial effect to T. castaneum but not to T. confusum. The two species were most productive in corn plus yeast, but this productivity was not significantly higher than in whole wheat flour plus yeast. Drawing upon the evidence available in the literature, and the present data, it is concluded that T. confusum is better adapted to utilize a wider variety of foods than T. castaneum and in order to satisfy its greater quantitative requirements for certain nutrients, this species engages in cannibalism more often than T. confusum. The result is that, when the two species are introduced into the same container, i.e. compete for food and space, T. confusum is more often eliminated than T. castaneum.
The crystal structure of thymidylate synthase from Pneumocystis carinii reveals a fungal insert important for drug design.

Thymidylate synthase from Pneumocystis carinii (PcTS) is an especially important drug target, since P. carinii is a fungus that causes opportunistic pneumonia infections in immune-compromised patients and is among the leading causes of death of AIDS patients. Thymidylate synthase (TS) is the sole enzyme responsible for the de novo production of deoxythymidine monophosphate and hence is crucial for DNA replication in every organism. Inhibitors selective for P. carinii TS over human TS would be greatly beneficial in combating this disease. The crystal structure of TS from P. carinii bound to its substrate, dUMP, and a cofactor mimic, CB3717, was determined to 2.6 A resolution. A comparison with other species of TS shows that the volume of the closed PcTS active-site is 20 % larger than that of five other TS closed active-sites. A two-residue proline insert that is strictly conserved among all fungal species of TS, and a novel C-terminal closing interaction involving a P. carinii-specific tyrosine residue are primarily responsible for this increase in volume. The structure suggests several options for designing an inhibitor specific to PcTS and avoiding interactions with human TS. Taking advantage of the residue substitutions of P. carinii TS over human TS enables the design of a selective inhibitor. Additionally, the larger volume of the active-site of PcTS is an important advantage for designing de novo inhibitors that will exclude the human TS active-site through steric hindrance.
The future of good news: social responsibility and visionary journalism

Abstract French ethicist Jean-Claude Bertrand's foreword to Good News: Social Ethics and the Press 1 suggests that society is no longer book-ended by fascism and communism. Of the prevailing social systems of the 20th century, only capitalism retains enough strength to impose its pragmatic, self-serving ethic on journalism. And yet, capitalism too seems to be either terminally ill, or functioning as a parasite draining its prey (the Earth) of the life on which both depend. In either event, old systems are fading and social change is evident in every corner. An opportunity for new approaches emerges.
Induction of HLA class I mRNA by cytokines in human fibroblasts: comparison of TNF, IL-1 and IFN-β

Abstract Expression of HLA class I antigens is known to be regulated by various cytokines at both the mRNA and protein levels. We have examined the induction of HLA-B7 by tumor necrosis factor α (TNF), interleukin 1α (IL-1) and interferon β (IFN-β) in normal human diploid FS-4 fibroblasts. Optimal induction of HLA-B7 by TNF at 24 h was shown to require a continuous presence of TNF. Since TNF also induces IFN-β in these cells and the latter cytokine itself has the capacity to upregulate HLA class 1 expression, we investigated the role of autocrine IFN-β in the induction of HLA-B7 by TNF. Experiments with neutralizing polyclonal antibodies to recombinant IFN-β showed that the induction of HLA-B7 mRNA by TNF was partially dependent on autocrine IFN-β. However, TNF and IFN-β induced HLA-B7 mRNA with similar kinetics and treatment with saturating concentrations of both TNF and IFN-β resulted in an additive or possibly synergistic response. The latter findings support the idea that induction of HLA class I by TNF is not mediated solely by autocrine IFN-β produced in response to TNF. In addition, experiments with the protein synthesis inhibitor cycloheximide suggested that the induction of mRNAs for both the heavy and light (β 2 -microglobulin) chains of the HLA class I antigen by TNF did not require de novo protein synthesis. IL-1 was also shown to increase steady-state mRNA levels of HLA-B7 with kinetics similar to those of TNF and IFN-β in FS-4 cells. Our data suggest that TNF stimulates gene expression of the HLA class I antigens through multiple mechanisms. Although one pathway of induction apparently involves autocrine IFN-β, available evidence suggests that de novo synthesis of IFN-β (or of some other protein) in response to TNF is not an important step in HLA-B7 induction. Rather, the slow kinetics of HLA-B7 induction by TNF can be explained by the need for a gradual and progressive accumulation of the activating signal(s) generated by TNF.