cssi/SciSciGPT-SciSciNet huggingface dataset:
Diurnal and seasonal variation of electron heat flux measured with the Poker Flat Incoherent‐Scatter Radar

[1] Measurements made with the Advanced Modular Incoherent Scatter Radar were used to calculate the average diurnal electron temperature and corresponding vertical heat flux above Poker Flat, Alaska. Our results show that both the electron heat flux and temperature exhibited seasonal variation during 12 consecutive months in 2009 and 2010, a period of exceptionally quiet solar and geomagnetic activity. Both the electron temperature and heat flux varied diurnally, with larger magnitudes observed during the day than night. Contrary to midlatitude measurements from the late 1960s, the downward heat fluxes above Poker Flat were found to vary significantly with season and were typically greater during summer than winter. The time-dependent topside electron heat flux is an important parameter describing magnetosphere-ionosphere coupling and it also drives boundary conditions in physics-based ionosphere models. Parameterizations of the average electron thermal flux and temperature sufficient for use in ionosphere models are provided. A physics-based high-latitude ionosphere model is used to demonstrate that a constant heat flux boundary condition leads to an electron temperature increase near local midnight that is not observed in the radar measurements. The resulting inaccuracy in electron temperature calculations leads to more than a 15% overestimate of daytime peak electron number density. Applying a time-varying heat flux boundary condition brings the model electron temperature and peak density to good agreement with measurements.
Biosynthesis of the Chondroitin Sulfate Proteoglycan PURIFICATION AND PROPERTIES OF XYLOSYLTRANSFERASE

Abstract Xylosyltransferase from embryonic chick epiphyseal cartilage catalyzes the transfer of xylose from UDP-xylose to particulate endogenous acceptors or to an exogenous protein acceptor obtained by Smith degradation of bovine chondroitin sulfate-protein complex. Use of the exogenous protein acceptor enabled determination of enzymic activity independently of endogenous acceptors. Homogenization of cartilage in buffers containing from 0.2 to 1 m KCl followed by centrifugation at 105,000 x g yielded soluble fractions which contained from 65 to 95% of the xylosyltransferase activity. The remainder of the activity was associated with the 105,000 x g sediment. Soluble enzyme was fractionated with ammonium sulfate and purified by centrifugation on density gradients or by gel filtration resulting in a 50-fold purification. The specific activities of xylosyltransferase in embryonic chick cartilage, brain, liver, and intestine were compared; enzyme activity was highest in cartilage. The specific activity of the transferase in brain was 8% of that from cartilage, whereas liver and intestine exhibited no measurable activity with the exogenous acceptor. Xylosyltransferase catalyzes the first of the sequential glycosyltransferase reactions required for synthesis of the chondroitin sulfate-protein linkage region and formation of polysaccharide chains. It is postulated that xylosyltransferase controls the initiation of chondroitin sulfate chains on core protein. The level of xylosyltransferase in tissue appears to be correlated with amounts of the mucopolysaccharide synthesized.
Welfare Reforms and Services for Children and Families: Setting a New Practice, Research, and Policy Agenda

This article addresses barriers to family and community self-sufficiency. Many of these barriers have resulted from policymakers' biased definitions of self-sufficiency and related social program reforms. Social workers need to understand the worldviews and values that underlie political definitions of self-sufficiency to have a greater influence on social policy. This article describes a more appropriate definition of self-sufficiency and illustrates its usefulness with an example of community research conducted to identify social support needs. The author recommends changes in social work practice and education that can enable the profession to have a stronger influence on social policy. Finally, to achieve this social justice goal and integrate policy development into clinical and community practice, the author proposes new research and policy agendas for the profession.
A reusable state-based guidance, navigation and control architecture for planetary missions

JPL has embarked on the Mission Data System (MDS) project to produce a reusable, integrated flight and ground software architecture. This architecture will then be adapted by future JPL planetary projects to form the basis of their flight and ground software. The architecture is based on identifying the states of the system under consideration. States include aspects of the system that must be controlled to accomplish mission objectives, as well as aspects that are uncontrollable but must be known. The architecture identifies methods to measure, estimate, model, and control some of these states. Some states are controlled by goals, and the natural hierarchy of the system is employed by recursively elaborating goals until primitive control actions are reached. Fault tolerance emerges naturally from this architecture. Failures are detected as discrepancies between state and model-based predictions of state. Fault responses are handled either by re-elaboration of goals, or by failures of goals invoking re-elaboration at higher levels. Failure modes an modelled as possible behaviors of the system, with corresponding state estimation processes. Architectural patterns are defined for concepts such as states, goals, and measurements. Aspects of state are captured in a state-analysis database. UML is used to capture mission requirements as Use Cases and Scenarios. Application of the state-based concepts to specific states is also captured in UML, achieving architectural consistency by adapting base classes for all architectural patterns.
hsp82 is an essential protein that is required in higher concentrations for growth of cells at higher temperatures.

Abstract hsp82 is one of the most highly conserved and abundantly synthesized heat shock proteins of eucaryotic cells. The yeast Saccharomyces cerevisiae contains two closely related genes in the HSP82 gene family. HSC82 was expressed constitutively at a very high level and was moderately induced by high temperatures. HSP82 was expressed constitutively at a much lower level and was more strongly induced by heat. Site-directed disruption mutations were produced in both genes. Cells homozygous for both mutations did not grow at any temperature. Cells carrying other combinations of the HSP82 and HSC82 mutations grew well at 25 degrees C, but their ability to grow at higher temperatures varied with gene copy number. Thus, HSP82 and HSC82 constitute an essential gene family in yeast cells. Although the two proteins had different patterns of expression, they appeared to have equivalent functions; growth at higher temperatures required higher concentrations of either protein. Biochemical analysis of hsp82 from vertebrate cells suggests that the protein binds to a variety of other cellular proteins, keeping them inactive until they have reached their proper intracellular location or have received the proper activation signal. We speculate that the reason cells require higher concentrations of hsp82 or hsc82 for growth at higher temperatures is to maintain proper levels of complex formation with these other proteins.
Virasoro constraints for D2n + 1−, E6−, E7−, E8−type minimal models coupled to 2D gravity

We find Virasoro constraints for D_(2n + 1−), E_6−, E_7−, E_8−type models analogous to the recently discovered Virasoro constraints for An-type models by Fukuma et al., and Dijkgraaf et al. We verify that the proposed Virasoro constraints give operator scaling dimensions identical to those found by Kostov. We check that these Virasoro constraints and, more generally, W-algebra constraints can be used to express correlation functions with non-primary operator in terms of correlation functions of primary operators only.
Translesion Synthesis across O6-Alkylguanine DNA Adducts by Recombinant Human DNA Polymerases

Previous studies have shown that replicative bacterial and viral DNA polymerases are able to bypass the mutagenic lesions O(6)-methyl and -benzyl (Bz) G. Recombinant human polymerase (pol) delta also copied past these two lesions but was totally blocked by O(6)-[4-oxo-4-(3-pyridyl)butyl] (Pob)G, an important mutagenic lesion formed following metabolic activation of the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. The human translesion pols iota and kappa produced mainly only 1-base incorporation opposite O(6)-MeG and O(6)-BzG and had very low activity in copying O(6)-PobG. Human pol eta copied past all three adducts. Steady-state kinetic analysis showed similar efficiencies of insertion opposite the O(6)-alkylG adducts for dCTP and dTTP with pol eta and kappa; pol iota showed a strong preference for dTTP. pol eta, iota, and kappa showed pre-steady-state kinetic bursts for dCTP incorporation opposite G and O(6)-MeG but little, if any, for O(6)-BzG or O(6)-PobG. Analysis of the pol eta O(6)-PobG products indicated that the insertion of G was opposite the base (C) 5' of the adduct, but this product was not extended. Mass spectrometry analysis of all of the pol eta primer extension products indicated multiple components, mainly with C or T inserted opposite O(6)-alkylG but with no deletions in the cases of O(6)-MeG and O(6)-PobG. With pol eta and O(6)-BzG, products were also obtained with -1 and -2 deletions and also with A inserted (opposite O(6)-BzG). The results with pol eta may be relevant to some mutations previously reported with O(6)-alkylG adducts in mammalian cells.
Interleaved continuum-rigid manipulation: An augmented approach for robotic minimally-invasive flexible catheter-based procedures

In recent years, minimally-invasive surgical systems based on flexible robotic manipulators have met with success. One major advantage of the flexible manipulator approach is its superior safety characteristics as compared to rigid manipulators. However, their soft compliant structure, in combination with internal friction, results in poor position and force regulation and has limited their use to simpler surgical procedures. In this paper, we discuss a new approach to continuum robotic manipulation that combines flexible, actively actuated continuum segments with small, limited stroke rigid-link actuators. The small rigid-link joints are interleaved between successive continuum segments and provide a redundant motion and error correction capability. The authors refer to this approach as interleaved continuum-rigid manipulation. In this paper, we describe the overall approach and investigate its performance using a one degree-of-freedom testbed and two degree-of-freedom planar simulation.
Sudden Death Risk in Syncope: The Role of The Implantable Cardioverter Defibrillator

Syncope is generally benign but when it is due to an underlying cardiovascular condition, the prognosis can be guarded. Patients with syncope may be at risk of dying suddenly from a ventricular arrhythmia especially if the collapse is caused by a poorly-tolerated, self-terminating, ventricular tachycardia (VT). If a similar VT recurs, and persists, it could initiate cardiac arrest, leading to sudden cardiac death. However, distinguishing which patient with syncope may benefit most from implantable cardioverter defibrillator (ICD) therapy, which can stop life-threatening and poorly tolerated VT, thereby preventing sudden cardiac death, remains an ongoing challenge. Careful assessment of the patient's underlying cardiovascular conditions, scrupulous attention to historical detail to assess potential causes for syncope, and risk stratification based upon clinical characteristics and short and long-term risks can help. This review focuses on the sudden death risk in patients with syncope and explores the role of the ICD to treat ventricular arrhythmias, prevent symptoms, and prevent death.
An evaluation of the role of 5-HT2 receptor antagonism during subchronic antipsychotic drug administration in rats

Abstract A widely postulated mechanism of action for the atypical profile of many novel antipsychotic drugs (APDs) is their relatively high affinity for 5-HT2 receptors. The present study investigated motor function and striatal dopamine (DA) efflux and metabolism in rats given 21 daily injections of drugs that differed in 5-HT2 affinity. These drugs included: risperidone (high 5-HT2A/2C/high D2), clozapine (high 5-HT2A/2C/low D2), haloperidol (low 5-HT2A/2C/high D2), haloperidol+ritanserin (selective 5-HT2A/2C), or vehicle. Rats injected with haloperidol (0.5 mg/kg) or haloperidol+ritanserin (0.5 mg/kg and 1.0 mg/kg, respectively) showed extreme catalepsy on day 1, but significantly decreased catalepsy when tested again on days 7 and 21. Acute or subchronic risperidone (0.05 or 0.5 mg/kg), clozapine (20 mg/kg), or vehicle did not induce significant catalepsy. Microdialysis performed 24 h after the last injection demonstrated that rats treated with risperidone, clozapine, or vehicle showed similar increases in DA efflux and metabolism following an acute injection of a selective DA D2/3 antagonist (raclopride, 0.5 mg/kg). DA efflux showed an attenuated response to raclopride in the haloperidol alone group; this effect was less apparent in the haloperidol+ritanserin group. However, both of these groups showed a similar tolerance effect to the raclopride-induced increase in DA metabolites. These results suggest that the profile seen after subchronic risperidone more closely resembles clozapine than haloperidol. While ritanserin reduced the tolerance-like effects of haloperidol on striatal DA efflux, the overall results demonstrate that potent 5-HT2 blockade alone may not entirely account for the distinctive profile of novel APDs.
Cold plasma selectivity and the possibility of a paradigm shift in cancer therapy

Plasma is an ionised gas that is typically generated in high-temperature laboratory conditions. However, recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperature close to room temperature. Both in-vitro and in-vivo studies revealed that cold plasmas selectively kill cancer cells. We show that: (a) cold plasma application selectively eradicates cancer cells in vitro without damaging normal cells; and (b) significantly reduces tumour size in vivo. It is shown that reactive oxygen species metabolism and oxidative stress responsive genes are deregulated. The development of cold plasma tumour ablation has the potential of shifting the current paradigm of cancer treatment and enabling the transformation of cancer treatment technologies by utilisation of another state of matter.
Low-Cost Fast VLSI Algorithm for Discrete Fourier Transform

A primeN-length discrete Fourier transform (DFT) can be reformulated into a (N-1)-length complex cyclic convolution and then implemented by systolic array or distributed arithmetic. In this paper, a recently proposed hardware efficient fast cyclic convolution algorithm is combined with the symmetry properties of DFT to get a new hardware efficient fast algorithm for small-length DFT, and then WFTA is used to control the increase of the hardware cost when the transform length Nis large. Compared with previously proposed low-cost DFT and FFT algorithms with computation complexity of O(logN), the new algorithm can save 30% to 50% multipliers on average and improve the average processing speed by a factor of 2, when DFT length Nvaries from 20 to 2040. Compared with previous prime-length DFT design, the proposed design can save large amount of hardware cost with the same processing speed when the transform length is long. Furthermore, the proposed design has much more choices for different applicable DFT transform lengths and the processing speed can be flexible and balanced with the hardware cost
Integrin αIIbβ3-mediated pp125FAK phosphorylation and platelet spreading on fibrinogen are regulated by PI 3-kinase

Abstract Activation of the focal adhesion kinase pp125FAK correlates with its phosphorylation on tyrosine residues and is mediated by multiple receptor-ligand pairs. In platelets, pp125FAK phosphorylation is triggered by α IIb β 3 integrin or FcγRII receptor interaction with immobilized fibrinogen and IgG, respectively. In this study we used platelets as a model system to explore the role of PI 3-kinase relative to pp125FAK phosphorylation. Treatment of the platelets with two PI 3-kinase inhibitors, wortmannin and LY294002, inhibited in a dose-dependent manner α IIb β 3 -mediated platelet spreading on fibrinogen having no effect on platelet spreading on IgG. Both inhibitors also completely abolished α IIb β 3 -mediated pp125FAK phosphorylation but not pp72syk phosphorylation. Furthermore, FcγRII- and thrombin-induced pp125FAK phosphorylation were not affected by wortmannin and LY294002. Finally, the PI 3-kinase inhibitors’ effect on α IIb β 3 -mediated spreading and pp125FAK phosphorylation was reversed by phorbol ester treatment. These results establish that the role of PI 3-kinase relative to pp125FAK phosphorylation in platelets is receptor type-specific yet essential for α IIb β 3 -mediated cell spreading and pp125FAK phosphorylation.
Polarization signatures of airborne particulates

Exploratory research has been conducted with the aim of com- pletely determining the polarization signatures of selected particulates as a function of wavelength. This may lead to a better understanding of the interaction between electromagnetic radiation and such materials, per- haps leading to the point detection of bio-aerosols present in the atmos- phere. To this end, a polarimeter capable of measuring the complete Mueller matrix of highly scattering samples in transmission and reflection (with good spectral resolution from 300 to 1100 nm) has been developed. The polarization properties of Bacillus subtilis (surrogate for anthrax spore) are compared to ambient particulate matter species such as pollen, dust, and soot. Differentiating features in the polarization signatures of these samples have been identified, thus demonstrating the potential applicabil- ity of this technique for the detection of bio-aerosol in the ambient atmos- phere. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attri- bution of the original publication, including its DOI. (DOI: 10.1117/1.OE.52.7.074106)
The stellar content of 30 doradus derived from spatially integrated ultraviolet spectra: A test of spectral synthesis models

Using the IUE satellite, we have obtained spatially integrated ultraviolet spectra of three areas within the giant H II region 30 Dor in the Large Magellanic Cloud. The spectra correspond to spatial reginswith sizes of 20 sec x 20 sec, 1 min x 1 min, and 3 min x 3 min, all of which are approximately centered on R136. We have performed a spectral synthesis analysis of the spectra of the two larger regions and compared the results with the known stellar content in these regions. The spectral synthesis models are sensitive to the ultraviolet continuum level, the P Cygni profile of the C Iv wavelength 1550 line, the absorption strength of the Si IV wavelength 1400 line, and the emission strength of the He II wavelength 1640 line. The intrinsic continuum levels and the profiles of these stellar wind lines provide constraints on the age and duration of the starburst episode within a region, as well as on the upper curoff mass of the initial mass function. From our analysis we find that the present-day value of the upper cutoff mass in the 1 min x 1 min and 3 min x 3 min regions has a lower limit of approximately 50 solar mass, a result which is in good agreement with several other recent determinations. The age of the starburst episode must be less than approximately 3 Myr, also in agreement with other estimates. Comparison of the observed total numbers of O and W-R stars with those predicted from the various models favors an instantaneous burst of star formation in the regions. However, the differences between the two burst scenarios we investigated (instantaneous and continuous) are small at such a young age, and distinguishing between the two is difficult. We are now confident that these spectral synthesis models can be used to determine the stellar content of more distant star-forming regions.
Prevalence and pathogenicity of Cryptosporidium andersoni in one Herd of Beef Cattle

Over a 35-week period from January to July 2002, a breed of Hereford beef cattle (H) and their hybrids were monitored. Five hundred and ninety-nine individual fecal samples from calves and 96 samples from their mothers were examined. First excretion of Cryptosporidium andersoni oocysts in calves was found in the 9th week after the start of calving (a calf 63-day old). The prevalence of C. andersoni in calves ranged from 11.1 to 92.9% depending on age. The mean prevalence in their mothers was found to be 43.8%. The size of oocysts was 8.48 +/- 0.78 x 6.41 +/- 0.59 microm. Infection intensity in calves ranged from 32 000 to 4 375 000 oocysts per gram (OPG) and in mothers from 78 000 to 2 552 000 OPG. Three cases of abomasal cryptosporidiosis slaughtered at the age of 81, 157 and 236 days were examined histologically and ultrastructurally [transmission electron microscopy (TEM) and scanning electron microscopy (SEM)]. Cryptosporidium infection of the abomasum was located in the upper half of the mucosal glands in the plicae spirales of the fundus, corpus and near the ostium omasoabomasicum. Cryptosporidia were not located in the glandular epithelium of the pars pylorica in the abomasum minimally 10 cm from pylorus. Histopathological changes in the site of cryptosporidial infection in the abomasum had a non-inflammatory character and included distinctive dilatation of infected parts of the glands with atrophy and metaplasia of the glandular epithelial cells, goblet cell activation and mucus hyperproduction. The TEM revealed a relatively small number of Cryptosporidium life cycle stages attached to glandular epithelial cells. In SEM the inner mucosal abomasal surface appeared swollen but was never infected by cryptosporidia.
Curriculum for Teachers: Four Traditions Within Pedagogical Philosophy

This article draws upon the history of teacher education to provide an introduction to 4 competing pedagogical philosophies. These 4 philosophies battled for control over curriculum for teachers during the period from 1890 to 1930. I begin by defining curriculum for teachers to include the liberal, the professional, and the experiential dimensions. Then, I identify 4 interest groups that sought to gain power over curriculum for teachers. I categorize these interest groups as the traditionalists, the integrationists, the technicians, and the romantics. Then, I explain how leading individuals from each interest group answered questions regarding human nature, the purpose of schooling, and curriculum for teachers. Finally, I argue that education schools should revitalize the integrationist tradition within pedagogical philosophy. This view has been forgotten for nearly 50 years, and the profession of teaching has suffered because of it.
Caesarean delivery and outcome in very low birthweight infants.

Objective To determine the relationship between mode of delivery, intraventricular haemorrhage (IVH), and mortality in very low birthweight (VLBW) infants. Study design A historical cohort study of infants admitted to a single level III neonatal intensive care unit during a five-year period. Infants < 1500 g born by caesarean delivery (n = 400) were compared to those born by vaginal delivery (n = 305). Results After controlling for potential confounding variables including: gestational age, fetal presentation, and multiple birth, caesarean delivery was not associated with a decreased odds of IVH (odds ratio 1.2, 95% CI 0.7–2.0), severe IVH (1.9, 0.9–4.0), or mortality (1.2, 0.6–2.4). Conclusions In our population of very low birthweight infants, caesarean delivery is not associated with a decreased risk for mortality or intraventricular haemorrhage.
Impact of renal insufficiency on clinical and angiographic outcomes following percutaneous coronary intervention with sirolimus‐eluting stents

Background Background: Sirolimus-eluting stents (SES) have been demonstrated to reduce restenosis. However, there have been few studies evaluating the impact of renal insufficiency on the angiographic as well as clinical outcomes after SES implantation. Methods: This study was composed of 304 consecutive patients having 361 lesions who underwent percutaneous coronary intervention with SES. The patients were divided into 3 groups according to renal function (group 1 [n = 204]; creatinine clearance (Ccr) ≥≥60ml/min, group 2 [n = 69]; Ccr <60 ml/min, group 3 [n = 31]; hemodialysis). Clinical and angiographic follow-up were evaluated at 8 months. Results: Clinical follow-up was obtained in all patients and angiographic follow-up was obtained in 283 patients (93.1%). Patients in group 3 showed a higher incidence of previous coronary artery bypass graft surgery, and there were more female gender, hypertensive, and less hyperlipidemia in this group. Late lumen loss at 8 months was significantly different among the 3 groups (group 1; 0.16 ± 0.46 mm, group 2; 0.44 ± 0.62 mm, group 3; 0.81 ± 0.88 mm, P < 0.0001). Major adverse cardiac events (MACE) were documented in 22 patients (10.8%) in group 1, 13patients (18.8%) in group 2, and 12 patients (38.7%) in group 3, respectively (P = 0.0002). Conclusion: Neointimal growth following SES implantation is more pronounced in patients with renal insufficiency, especially those undergoing dialysis, compared with patients with normal renal function. Regardless of the beneficial effect of SES, the increased risk of MACE mainly due to high incidence of target vessel revascularization in the subgroup of patients with renal insufficiency should be taken into account. © 2006 Wiley-Liss, Inc.
Extraterrestrial influences on mantle plume activity

Abstract We use time series analysis to compare the impact histories of the Earth and Moon with the record of mantle plume activity. We use events with errors in their ages of ≤150 Ma. The terrestrial and lunar impact records, when smoothed at a 45-Ma interval, correlate at a 97% confidence level. This high confidence level suggests that we have an adequate sampling of most of the major impact events on the Earth. We then test the idea that existing mantle plumes may be strengthened by impacts. When smoothed at a 45-Ma interval, strong plumes correlate with the terrestrial impact record at better than a 99% confidence level. No time lag is discernible between the data sets, which is expected given their present error level. When the time series are smoothed at a 30-Ma interval, there are 10 major peaks in impact activity. Nine out of ten of these peaks have a counterpart in either or both of the strong mantle plume or the mantle plume time series. As a result, the strong mantle plume and the impact time series correlate at the 97% confidence level. The mantle plume and the impact time series correlate at the 90% confidence level. Finally, the Deccan plume showed greatly increased activity immediately after the Chixculub impact. The results of our analysis suggest that large meteorite and cometary impacts may well increase the amount of volcanism from already active mantle plumes.
Active and cooperative learning: further tips and tricks (part 3)

Active and cooperative learning can energize the instructor, students, and the classroom. This third article in a series on active and cooperative learning discusses the characteristics that make groups effective as well as techniques for the formation and evaluation of groups. Icebreaking exercises that can demonstrate the value of cooperation and teamwork are also discussed.
On multiple phase transitions for branching Markov chains

We consider branching Markov chains on a countable set. We give a necessary and sufficient condition in terms of the transition kernel of the underlying Markov chain to have two phase transitions. We compute the critical values. We apply this result to prove that asymmetric branching random walks onZ have two phase transitions.
A Multilingual Handwriting Approach to CAPTCHA

Nowadays World Wide Web makes use of Human Interactive Proofs and CAPTCHA to distinguish legitimate users from bots. This paper presents an overview of current systems and their weaknesses and proposes a unified theory for a multilingual handwriting CAPTCHA. We further describe our French and Spanish CAPTCHAs, as an extension to the English version, with the potential of being more useful on websites in those languages. Highly interdisciplinary techniques used to generate our CAPTCHAs are also discussed.
Flare management for 40-nm logic devices

Since flare-related CD variation was observed in some 40-nm test chips, we evaluated the flare level of an ArF immersion scanner by the Kirk method. We found that the tool flare for a 1.3-μm pad was more than 5% and the short-range flare (scattering range < 10 μm) was quite large when the optics were degraded. Optics maintenance reduced the tool flare to about 2%. An evaluation of the impact of short-range flare on the space CDs of 40-nm logic devices revealed it to be quite large. The point spread function for flare was determined from measured flare data, and the flare density was calculated for various patterns. A simulation analysis showed that the measured CD error was closely related to flare density. Since the impact of a change in dose on space CD is nonlinear, the impact of a change in flare is also nonlinear. Simulations using tool flare and flare density can predict most of the CD error. In the active layer of 40-nm logic devices, the flare density is generally in the range of 40-70% for critical space patterns. Varying the dose control pattern from small-area L/S (< 5 μm square) to large-area L/S (50 μm square) should reduce the impact of flare on space CD. Patterns with a medium flare density are preferable for dose control.
Effects of thermal activation on the oxidation pathways of methanol at bulk Pt–Ru alloy electrodes

Abstract The competition between pathways that lead to adsorbed CO and CO 2 during the electrochemical oxidation of 1.0 M methanol in 0.1 M HClO 4 on two bulk Pt–Ru alloys (10 at.% Ru ( X Ru ≈0.1) and 90 at.% Ru ( X Ru ≈0.9)) was investigated for temperatures in the range of 25–80°C. On the high Ru content alloy studied ( X Ru ≈0.9), the dissociative chemisorption of methanol was inhibited below 70°C; the faradaic current for methanol oxidation was low, and only small quantities of adsorbed CO and CO 2 were detected with infrared spectroscopy between 0.2–0.8 V (vs. RHE). At 80°C, strong infrared bands from CO 2 and adsorbed, atop coordinated CO were observed over the potential ranges of 0.4–0.8 V and 0.2–0.8 V, respectively. The infrared measurements are consistent with the observation that bulk, high Ru content alloy electrodes appear passivated toward methanol oxidation below 70°C. On the low Ru content alloy studied ( X Ru ≈0.1), the methanol surface chemistry was similar to that of pure, polycrystalline Pt, but the electrode was more poison resistant than Pt. For both alloys, the persistence of strong adsorbed CO bands and rapid CO 2 production between 0.4–0.8 V suggests CO functions as a reactive species with high steady-state coverages at these potentials.
Photodissociation of indium oxide cluster cations

Abstract Indium oxide cations of the form In n O m + are produced by laser vaporization in a pulsed nozzle source and detected with time of flight mass spectrometry. The In 2 O + and In 3 O + ions have high relative intensities in the mass spectra of clusters sampled directly from the source. Cluster cations are mass-selected and photodissociated using the third harmonic (355 nm) of a Nd:YAG laser. The elimination of indium cation is the dominant loss channel for all cluster cations. However, certain other clusters, i.e., In 2 O + , In 2 O 2 , In 3 O + and In 3 O 2 + are produced as fragments from several cluster sizes and are thus identified as particularly stable. Density functional theory calculations are employed for selected species to determine their structures and relative stabilities. The Wade–Mingos electron counting rules are found to be inappropriate for these systems because their bonding is primarily ionic.
Minimal RNA aptamer sequences that can inhibit or alleviate noncompetitive inhibition of the muscle-type nicotinic acetylcholine receptor.

Combinatorially synthesized nucleotide polymers have been used during the last decade to find ligands that bind to specific sites on biological molecules, including membrane-bound proteins such as the nicotinic acetylcholine receptors (nAChRs). The neurotransmitter receptors belong to a group of four structurally related proteins that regulate signal transmission between ~1011 neurons of the mammalian nervous system. The nAChRs are inhibited by compounds such as the anticonvulsant MK-801 [(+)-dizocilpine] and abused drugs such as cocaine. Based on predictions arising from the mechanism of receptor inhibition by MK-801 and cocaine, we developed two classes of RNA aptamers: class I members, which inhibit the nAChR, and class II members, which alleviate inhibition of the receptor by MK-801 and cocaine. The systematic evolution of ligands by the exponential enrichment (SELEX) method was used to obtain these compounds. Here, we report that we have truncated RNA aptamers in each class to determine the minimal nucleic acid sequence that retains the characteristic function for which the aptamer was originally selected. We demonstrate that a truncated class I aptamer containing a sequence of seven nucleotides inhibits the nAChR and that a truncated class II aptamer containing a sequence of only four nucleotides can alleviate MK-801 inhibition.
Temperature-sensitive Glycosaminoglycan Biosynthesis in a Chinese Hamster Ovary Cell Mutant Containing a Point Mutation in Glucuronyltransferase I

In previous studies, we reported the isolation and characterization of a Chinese hamster ovary cell mutant (pgsG) defective in glucuronyltransferase I (GlcATI). This enzyme adds the terminal GlcA residue in the core protein-linkage tetrasaccharide (GlcAβ1,3Galβ1,3Galβ1, 4Xylβ-O-) on which glycosaminoglycan assembly occurs (Bai, X. M., Wei, G., Sinha, A., and Esko, J. D. (1999) J. Biol. Chem. 274, 13017–13024; Wei, G., Bai, X. M., Sarkar, A. K., and Esko, J. D. (1999) J. Biol. Chem. 274, 7857–7864). Here we show that incorporation of 35SO4 into glycosaminoglycans in the mutant is temperature-sensitive, with greater synthesis occurring at 33 °C compared with 37 °C. Wild-type cells show the opposite thermal dependence. Rabbit antiserum to hamster GlcATI failed to detect cross-reactive material in pgsG cells by immunofluorescence and Western blotting. Furthermore, expression of chimeric proteins composed of mutant GlcATI fused to IgG binding domain of protein A or to green fluorescent protein did not yield the proteins at the expected mass. The green fluorescent protein-tagged version appeared as a truncated protein, and immunofluorescence showed large perinuclear bodies at 30 °C. At 37 °C, the fusion protein was not readily detectable. Sequencing cDNAs from mutant and wild-type cells revealed a single base transition (G331A) in the open reading frame in pgsG cells, which resulted in a Val-111 → Met substitution. These data suggest that pgsG cells contain a labile form of GlcATI that causes conditional expression of glycosaminoglycans dependent on temperature.
Hepatic hemangiomas: a multi-institutional study of appearance on T2-weighted and serial gadolinium-enhanced gradient-echo MR images.

PURPOSE: To define the appearance of hepatic hemangiomas on T2-weighted and serial gadolinium-enhanced gradient-echo magnetic resonance (MR) images. MATERIALS AND METHODS: In four university hospitals, with 1.0- or 1.5-T MR imaging, T2-weighted and T1-weighted gradient-echo images were obtained in 66 adult patients before and at 1, 45, and 90 seconds and 10 minutes after injection of a gadolinium chelate. Hemangiomas were categorized as small ( 5.0-cm) tumors. RESULTS: In all, 154 hemangiomas were depicted (81 small, 56 medium, and 17 large tumors). All 154 lesions were hyperintense on T2-weighted images. Three patterns of contrast enhancement were observed: (a) uniform enhancement at 1 second (35 of 81 small lesions and no medium or large lesions), (b) peripheral nodular enhancement progressing centripetally to uniform enhancement (75 of all 154 lesions), and (c) peripheral nodular enhancement with persistent hypointensity centrally (44 of all 154 lesi...
The great plains Garrison Diversion Unit and the search for an environmental ethic

The Garrison Diversion Unit (GDU) was authorized by Congress in 1965. It is one of the largest and most expensive public works projects ever undertaken in the United States. When completed, it may become the last major federal irrigation scheme constructed in the west. Its principal purposes are: (1) to irrigate some 250,000 acres of arable land in North Dakota, (2) provide water for municipal and industrial use in fourteen communities, and (3) enhance recreational opportunities and fish and wildlife management programs within, and adjacent to, the canals and reservoirs resulting from its construction. The project is to be financed by hydropower sales from Lake Sakakawea, created when Garrison Dam was completed in 1956.1
Entanglement Detection: Complexity and Shannon Entropic Criteria

Entanglement plays a key role in quantum information. The separability problem arises: how to prove that a given quantum state is entangled? Covariance-matrix-based entanglement criteria are the most important and widely used approach to this problem in continuous variable systems. Here, the separability problem is systematically studied in the more experimentally realistic setting that the questioned state is only partly known. A simple general formalism is proposed for this variant of the separability problem. It builds relations between certain classes of criteria and bounds the power of these criteria. In particular, it shows the equivalence of many seemingly different covariance-matrix-based criteria; it offers guidance on the study of and reveals the inherent limitations of covariance-matrix-based criteria. Also, a Shannon entropic criterion is proposed for m ⊕ n-mode states. It unifies and improves many known covariance-matrix-based criteria and Shannon entropic criteria; it is necessary and sufficient for 1 ⊕ n-mode Gaussian states and m ⊕ n-mode bisymmetric Gaussian states.
Rethinking Silence as Support: Normalizing Lesbian and Gay Teacher Identities Through Models and Conversations in Student Teaching

ABSTRACT In the vein of action research, the author examines his practice of matching lesbian and gay student teachers with a lesbian or gay cooperating teacher for field placement. This article addresses several questions. In what ways, if any, do lesbian and gay teachers help new teachers cope with and interrupt homophobia? How do they help student teachers to negotiate teacher and sexual identities? What role, if any, do they play as new teachers make decisions about sharing their sexual orientation to others in school, particularly students? Although student teachers appreciate their cooperating teachers as role models, they find a lack of conversation with them about negotiating identities as both teachers and as lesbian or gay leads to missed opportunities or unintended learning. Student teachers struggled to translate their cooperating teachers' methods of coming out to their circumstances.
THE TSARIST GOVERNMENT AND THE POGROMS OF 1903—06

Russia has never been a good place to be a Jew, particularly in the last century. The history of Russian Jewry is one of discrimination punctuated by episodes of violence leading to mass emigration. It would be a mistake to understand these past 100 years as a culmination of a long tradition of Russian antipathy toward Jews. Prior to the Polish partitions in the late 18th century there lived only a handful of Jews in Russia. Violent attacks, or pogroms, were virtually nonexistent before 1881. When the violence did begin, damage to Russian Jewry was massive. Three times, between the years 1881 and 1921, Jews were beaten, killed and burned out of their homes. Each attack was more brutal than the preceding. Mass destruction, thousands killed, hundreds of thousands wounded, orphaned and rendered homelessthis was the legacy of pogroms. The first wave of pogroms took place in 1881, shortly after the assassination of Alexander II by the radical group the People's Will (Narodnaya Volya). The second wave swept the Pale of Settlement in 1903-06, during the years of the Russo-Japanese War and the Revolution of 1905. The third series unfolded against the backdrop of the Russian Civil War. The focus of this essay is pogroms occurring directly before and during the years of the 1905 Revolution. The first of these took place in the Bessarabian city of Kishinev, in April, 1903. After Kishinev, there were over 650 pogroms during the next three year period. By 1906, when the government of Nicholas II had regained its pre-Revolutionary control, the violence stopped, not to reappear again until the Civil War. The traditional interpretation places the responsibility for these events on the government of Nicholas II. According to this view, the tsar and his ministers willingly and consciously sponsored these attacks as a means of dealing with the burgeoning revolutionary movement. The traditional school explains pogroms as the autocracy's tool in coping with a disgruntled peasantry and a desperately poor working class. The government of Nicholas II sought to redirect discontent away from itself toward a more acceptable and defenseless scapegoat. The anti-Jewish
Conformational Distributions Of Flexible Molecules From Steady State Fluorescence Energy Transfer

We demonstrate that distance distributions between two sites on flexible molecules can be recovered using steady state measurements of fluorescence energy transfer. The characteristic Forster distance (R°) for energy transfer was varied by collisional quenching of the donor, which decreases its quantum yield. The measured transfer efficiencies for each value of R. provide a different average of the distance distribution. The R.-dependent transfer efficiencies, when analyzed by non linear least- squares, were found to reliably determine the distance distribution, as shown by agreement with the frequency-domain method (Chem. Phys. Lett. 1987, 138:587-593).© (1988) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Diencephalic regulation of plasma LH, ovulation, and sexual behavior in the rat.

Female rats which displayed a regular pattern of four-day estrous cycles were used to study the effects of surgical cuts placed at the posterior border of the optic chiasm on mating, ovulation, and plasma LH concentration. Two additional groups of four-day cycling females served as mated and unmated controls, autopsied on a morning of estrus. It was found that interruption of fibers in the anterior region of the basomedial hypothalamus results in constant behavioral receptivity maintained over several weeks of testing. Mating did not induce ovulation; however, females with the cut at the chiasmatic border were capable of ovulating in response to exogenous LH treatment 38-40 days after surgical treatment. Ovarian histology suggested that the largest (atretic) follicles did not ovulate, but that a developing cohort of follicles ovulated to exogenous LH. Plasma LH was significantly elevated at the time of autopsy in the operated animals in contrast to the controls. Uterine weights suggest that endogenous est...
Electrical alternans in wide complex tachycardias

The occurrence of electrical alternation of 0.1 mV or greater of the QRS or T wave was analyzed in 156 electrocardiograms that showed wide QRS complex tachycardias from 91 patients. One hundred thirty-six ventricular tachycardias (VT) were recorded from 74 patients and 20 supraventricular tachycardias (SVT) from 17 patients. Alternans was present in 42 tracings (27%) from 35 patients (38%) and was equally frequent in the patients with VT (39%) and those with SVT (35%). Alternans occurred in 36 VTs (27%) and 6 SVTs (30%). Tachycardias with alternans had a shorter mean cycle length than tachycardias without alternans (339 +/- 53 vs 368 +/- 85 ms, p less than 0.05), but were not associated with a particular QRS morphology or axis. Alternans was most frequent in leads V2 and V3 and was seen in more leads during SVT than VT (7.2 +/- 2.6 vs 3.7 +/- 2.5, p less than 0.005). All SVTs with alternans incorporated an atrioventricular bypass tract. Electrical alternans occurs frequently in wide QRS tachycardias. Alone, it does not help differentiate VT from SVT. SVTs utilizing bypass tracts frequently show alternans even if the QRS is wide, and this finding may be useful in determining the mechanism of SVTs with aberrant intraventricular conduction.
Components of the courtship-stimulating pheromone blend of young male Drosophila melanogaster: (Z)-13-tritriacontene and (Z)-11-tritriacontene

Abstract The 33 carbon alkenes, (Z)-13-tritriacontene and (Z)-11-tritriacontene, have been identified as the major components of the homosexual courtship-stimulating pheromone blend of Drosophila melanogaster (Canton S strain). (Z)-13-Tritriacontene was the most active of the two alkenes. The active alkenes were isolated from the cuticular hydrocarbon mixture of alkanes, alkadienes and other inactive 31, 29, and 27 carbon alkenes. Synthetic alkenes alone and in combination were tested in bioassay to verify the activity of the pheromone blend components.
Enterobacter agglomerans, phosphate solubilizing bacteria, and microbial activity in soil: Effect of carbon sources

Abstract Soil contains large amount of phosphorus that exists in insoluble forms. Some soil bacteria like Enterobacter agglomerans may have the capability to solubilize insoluble P and hydrolyze organic P for plant growth. These phosphate-solubilizing bacteria (PSB) may be stimulated by organic energy sources added to or found in soils. To examine the effect of organic energy sources on the survival of E. agglomerans and soil microbial activities, E. agglomerans were introduced into unsterilized soil containing 1% hydroxyapatite (HA) and either 1% glucose (GL), phytic acid dodecasodium salt (PA), glycerol-2-phosphate disodium salt (GP), soluble starch (SS) or no addition. Two controls were used: control 1: without E. agglomerans (C1) and control 2: with E. agglomerans (C2). E. agglomerans introduced in C2 treatment increased soil microbial biomass, phosphatase activity, and P solubilization compared to C1 at 2 d; however, with time there was no significant difference in treatments. Acid and alkaline phosphatase activities in GL and SS treatments were greater when compared to PA and GP; however, P concentration was greater in PA and GP treatments. Phytic acid and glycerol-2-phosphate may provide the necessary energy to solubilize HA as well as organic phosphate which is hydrolyzed by phosphatase. Soil microbial biomass C in GL and SS treatments were higher compared to PA and GP treatments. When only LB culture was added, E. agglomerans was not detectable after 22 d. Any additional mineralizable C contributes to the survival of E. agglomerans with time.