cssi/SciSciGPT-SciSciNet huggingface dataset:
The Mask Is Off

In how many ways could a government fail in anticipating and mitigating a public health crisis? The coronavirus pandemic that emerged from a continent away made 2020 the deadliest year in American history. When future historians look back to the devastation the pandemic wrought on the land and its long-term social, political, and economic fallout, they will find a frayed capacity behind the federal government’s response. In this chapter, the chaos and debility are shown belying the notion of a government led by an accountable and energetic executive. Instead, a superpower’s failures in several dimensions prevented it from heading off the pandemic’s most brutal effects, even as its unitary executive commanded tremendous influence on the stage. Bureaucratic, democratic, and civic resilience were all at once put to the test.
The Saturn system

Prior to the Voyager flybys in 1980 and 1981 (Table 8.1), the satellites of Saturn appeared as little more than tiny spots of light, even when seen through the most powerful Earth-based telescopes. The Voyager mission not only transformed these spots into objects available for geologic study, but also enabled discovery of at least eight additional satellites, bringing the total known number to 17 (Fig. 9.1). These represent a remarkable diversity of objects, including various icy moons (many of which show signs of repeated resurfacing), the only known satellite in the Solar System to have an appreciable atmosphere (Titan), and a host of “small bodies” (a few tens of kilometers in size) which can be compared with the moons of Mars (Phobos and Deimos) and the innermost moon of Jupiter (Amalthea).
Photonic arbitrary waveform generator

An arbitrary waveform generator is demonstrated using WDM fiber-optic components. Cross-gain modulation method in a semiconductor optical amplifier is implemented to convert 3-bit digital words to an arbitrary analog waveform at a rate of 3 Gb/s.
Microwave Photonics: Technological Evolution and Its Applications

Since the late 1980s, novel microwave photonics techniques have been developed that lead to a performance superior to that obtained with the purely electronic systems. This discipline originated from the concept of light interaction with semiconductor devices and circuits, and has now branched to a number of applications dealing primarily with antenna technology and remote and signal processing. This article reviews the previously established optically controlled devices and circuits, followed by discussions of both directly and externally modulated fiberoptic links. Fiberoptic link performance is discussed in terms of system-level figures of merit. A multifunction optoelectronic circuit is also discussed. Design innovations are introduced in low-cost source packaging and system architectures of optically fed large phased-array antennas. One important advantage of photonics in microwave systems is the optical signal processing based on low-loss optical fibers. Examples of memory loops, narrowband notch filters, and transversal filters are introduced. All-optical analog-to-digital conversion and diffuse photon near-IR imaging are two new application areas that are currently under development. The GSPS optical ADC concepts are presented using mode-locked lasers for optical sampling. Quantization could be achieved in both electrical and optical domains. Finally, an approach based on the diffused photon near-infrared imaging technique is discussed, leading to medical monitoring and biomedical imaging systems. As the modulation frequency expands to microwave frequencies, a higher spatial resolution is observed. Keywords: microwave photonics; integrated circuit; millimeter wave; fiberoptic links; phased array antenna; near-infrared spectroscopy
Unexpected reactivities of T cells selected by a single MHC-peptide ligand.

In H2-DM mutant mice, most MHC class II molecules are bound by a single peptide, CLIP, derived from the class II-associated invariant chain. Previous studies showed that H2-DM− cells are defective in presenting synthetic peptides to class II-restricted T cells. In sharp contrast, however, the same peptides elicited strong CD4+ T cell responses in H2-DM− animals. We now provide an explanation for this apparent discrepancy. Peptide-specific CD4+ T cells from wild-type mice were efficiently stimulated by H2-DM+, but not by H2-DM− cells pulsed with the cognate peptide. In sharp contrast, CD4+ T cells from mutant animals specific for the same MHC-peptide combination recognized peptide-pulsed H2-DM+ and H2-DM− cells equally well. In addition, unlike Ag-specific T cells from wild-type animals, the reactivities of peptide-specific T cells from mutant animals could not be efficiently blocked by Abs specific for the cognate MHC class II-peptide combination. We further demonstrated that the distinct reactivities of CD4+ T cells from H2-DM+ and H2-DM− mice are due to differences in thymic selection. Collectively, these findings indicate that the CD4+ T cell repertoires of H2-DM+ and H2-DM− mice are remarkably different.
Toward a new constitution for a future country

This paper outlines a preliminary radical plan for a constitution based primarily on recent contributions on mechanisms for choice of public goods and on constitutional rules and concepts, but based also on experience with present constitutions, corporate charters, and private arbitration procedures. It uses the standard economic perspective, disregarding such motives as herd instincts and the desire to serve the public interest. The result is markedly different from existing constitutions.
Effect of Lavender Aromatherapy on Acute-Stressed Horses

Methods to reduce the effects of acute stress could benefit the equine industry; therefore, the objective of this experiment was to determine whether aromatherapy would hasten the recovery time in acute-stressed horses. A total of seven horses were used in this experiment, using a crossover design where each horse received each treatment 7 days apart. The heart rates (HRs) and respiratory rates (RRs) were recorded for each horse at rest in stalls; then an air horn was blown twice for 15 seconds. The horses were allowed 60 seconds to calm, and then the stressed HRs and RRs were recorded. Control-treated horses were then exposed to humidified air, whereas aromatherapy-treated horses were exposed to humidified air with a 20% mixture of 100% pure lavender essential oil for
The effect of a six-week program of yoga and meditation on brachial artery reactivity: do psychosocial interventions affect vascular tone?

Background: Chronic stress is estimated to increase the risk of cardiovascular (CV) events two-fold. Although stress reduction has been linked to a reduction in CV events, little is known regarding its exact mechanism of benefit. Hypothesis: Yoga and meditation will improve parameters of endothelial function. Methods: We examined the effects of yoga and meditation on hemodynamic and laboratory parameters as well as on endothelial function in a 6-week pilot study. Systolic and diastolic blood pressures, heart rate, body mass index (BMI), fasting glucose, lipids, hs C-reactive protein (CRP), and endothelial function (as assessed by brachial artery reactivity) were all studied at baseline and after 6 weeks of yoga practice. Results: A course in yoga and meditation was given to the subjects for 1.5 h three times weekly for 6 weeks and subjects were instructed to continue their efforts at home. This prospective cohort study included 33 subjects (mean age 55 ± 11 years) both with (30%) and without (70%) established coronary artery disease (CAD). There were significant reductions in blood pressure, heart rate, and BMI in the total cohort with yoga. None of the laboratory parameters changed significantly with yoga. For the total cohort there was no significant improvement in endothelial-dependent vasodilatation with yoga training and meditation compared with baseline (16.7% relative improvement from 7.2-8.4%; p = 0.3). In the group with CAD, endothelial-dependent vasodilatation improved 69% with yoga training (6.38-10.78%; p = 0.09). Conclusion: Yoga and meditation appear to improve endothelial function in subjects with CAD.
Numerical simulation of thermal transport associated with a continuously moving flat sheet in materials processing

The thermal transport that arises due to the continuous motion of a heated plate or sheet in manufacturing processes such as hot rolling, extrusion, continuous casting, and drawing is numerically investigated. The resulting temperature distribution in the solid is influenced by the associated flow in the ambient fluid, which is taken as stationary far from this moving surface, and is of particular interest in this work. A numerical study is carried out, assuming a two-dimensional, steady circumstance with laminar flow in the fluid. The full governing equations, including buoyancy effects, are solved, employing finite-difference techniques. The effect of various governing parameters, such as the Peclet number, Pe, the mixed convection parameter, Gr/Re{sup 2}, and the conductivity parameter, K{sub f}/K{sub s}, which determine the temperature and flow fluids, is studied in detail. Also, the effect of the boundary conditions, particularly at the location of the emergence of the plate, on the downstream thermal transport is investigated. The penetration of the conductive effects, upstream of the point of emergence, is found to be significant. The effect of buoyancy is found to be more prominent when the plate is moving vertically upward than when it is moving horizontally. The appropriate boundary conditions andmore » their imposition in the numerical scheme are discussed for a variety of practical circumstances.« less
Steroid Receptor Coactivator-1 Mediates Estrogenic Actions to Prevent Body Weight Gain in Female Mice

Estrogen receptor-α (ERα) expressed by hypothalamic proopiomelanocortin and steroidogenic factor-1 neurons largely mediates the antiobesity effects of estrogens in females. However, the critical molecular events that are coupled to ERα and mediate estrogenic effects on energy balance remain unknown. In the current study, we demonstrated that steroid receptor coactivator-1 (SRC1), a nuclear receptor coactivator, is abundantly expressed by both proopiomelanocortin and steroidogenic factor-1 neurons. We further showed that central administration of an ERα agonist, propyl pyrazole triol, acutely increases physical interaction between SRC1 and ERα in the hypothalamus. Finally, we demonstrated that the effects of estrogens on energy homeostasis are significantly blunted in female mice lacking SRC1 globally. Collectively our results indicate that SRC1 is functionally required to mediate the antiobesity effects of estrogen-ERα signals.
A minor role for lipocalin 2 in high-fat diet-induced glucose intolerance

Adipose tissue controls energy homeostasis and systemic insulin sensitivity through the elaboration of a series of cytokines and hormones, collectively termed “adipokines.” We and others have ident...
Strain and interfacial bond type effects on structural quality of InAs/Ga(As,Sb) superlattices grown on InAs substrates

A series of InAs/Ga(As,Sb) superlattices were grown on InAs substrates by molecular beam epitaxy. The samples were grown in a manner that allowed the nature of the interfacial bonds (either GaAs or In(As,Sb)-like) to be controlled). In some of the samples the bond type-related strain was accommodated by adjusting the Sb mole fraction to nearly lattice match the superlattice to the substrate regardless of bond configuration. High-resolution X-ray diffraction measurements and transmission electron microscopy images reveal that samples grown with In(As,Sb)-like bonds on top of the InAs layers exhibit superior structural quality. Samples with GaAs-like bonds at both interfaces are far inferior to the others.
Fabrication of highly aligned YBa2Cu3O7−δ-Ag melt-textured composites

Abstract Liquid phase processing techniques with slow cooling through the peritectic transformation have been utilized to fabricate bulk aligned 123-Ag composites. Coarse (∼30–40 μm) and fine (∼5–10 μm) particles of silver are distributed between and within the 123 grains. Although the processing temperatures employed are much higher than the melting point of silver, particles of silver are retained behind the advancing solid-liquid interface. The peritectic reaction occurs at the solid-liquid interface and the rate of the reaction is limited by diffusion between the two solid phases, hence the transformation invariably results in some unreacted phases. Ellipsoidal, Y 2 BaCuO itx particles varying in size from 10–25 μm are trapped within the 123 phase. In addition, regions of CuO and BaCuO 2 are present in the sample as separate phases. Silver particles are also dispersed in these insulating regions of the microstructure. The 123-Ag composites have superior mechanical properties compared to melt-textured stoichiometric 123 samples. A detailed study describing the effects of processing on the microstructureof these aligned composites is reported.
Interactions of plant resistance and insecticides on the development and survival of Bactericerca cockerelli [Sulc] (Homoptera: Psyllidae)

Abstract Relatively few studies have investigated potential interactions of host plant resistance and insecticides for insect control. To examine possible interactions, host plant resistance was measured independently for four tomato cultivars and one wild tomato accession against tomato psyllids, Bactericerca [ Paratrioza ] cockerelli [Sulc] (Homoptera: Psyllidae). Plant lines tested included the commercial cultivars ‘Shady Lady’, ‘Yellow Pear’, ‘7718 VFN’, ‘QualiT 21’ and the plant accession PI 134417. Cultivars showed variable resistance; PI 134417 was the most resistant line tested with significantly reduced developmental rates and survivorship. Insecticides tested against the commercial cultivars included a kaolin-based particle film, pymetrozine, pyriproxyfen, spinosad and imidacloprid. Although all chemicals significantly reduced egg–adult survivorship, the effectiveness of some insecticides varied between-plant lines as measured by survivorship, development time and growth index (GI) data, which indicated significant interactions between-plant lines and insecticides. For example, survivorship from egg to adult varied significantly between cultivars under pymetrozine treatment. For kaolin-based particle film applications, numbers of days required to reach the adult stage were significantly different between cultivars. GI values were also variable between cultivars for pymetrozine and spinosad. Although all chemicals tested had potential for psyllid control within an integrated pest management program, imidacloprid and pyriproxyfen worked consistently well on all cultivars tested. For the other chemicals, cultivar selection could influence pesticide efficacy.
SU-GG-J-87: State Based Motion Tracking and Prediction Using a Hidden Markov Model

Purpose: To evaluate the effectiveness of a probabilistic mathematical model at tracking and predicting respiratory motion gated and motion compensated in radiation therapy.Method and Materials: A previously recorded set of fiducial marker positions were recorded at 30Hz for four patients and modeled into finite states representing the natural breathing states of Exhale, Inhale, and End of Exhale. State sequences and observables representing those sequences were analyzed using a hidden Markov model (HMM) to predict a future set of sequences and new observables. Velocities and other parameters were clustered using a k‐means clustering algorithm to associate each state with a set of observables such that a prediction of state would enable a prediction of velocity. Positional results were then compared to several other published predictive models in terms of their overall RMS errors from actual position. System delay times from 33 to 1000 ms were considered and for additional comparison, a simple time average model which bases future sequence prediction on average past state lengths was also computed. State sequences which are known a priori to fit the data were fed into the hidden Markov model prediction algorithm to set a theoretical limit of the predictive power of the model at ∼20% of the motion amplitude. Results: RMS errors for motion traces modeled by the hidden Markov model show improvement over linear and phase shift type prediction models at latencies higher than 500 ms, but do not reach the target lower limit. RMS errors for the time average model approach the theoretical limit of the HMM, even though their state sequences are poorly correlated with sequences known to fit the data. Conclusion: Hidden Markov models and their simpler probabilistic counterparts show much promise for use in online prediction of tumor motion for improved accuracy of radiation delivery.
Actions of a histaminergic/peptidergic projection neuron on rhythmic motor patterns in the stomatogastric nervous system of the crab Cancer borealis

Histamine is a neurotransmitter with actions throughout the nervous system of vertebrates and invertebrates. Nevertheless, the actions of only a few identified histamine-containing neurons have been characterized. Here, we present the actions of a histaminergic projection neuron on the rhythmically active pyloric and gastric mill circuits within the stomatogastric ganglion (STG) of the crab Cancer borealis. An antiserum generated against histamine labeled profiles throughout the C. borealis stomatogastric nervous system. Labeling occurred in several somata and neuropil within the paired commissural ganglia as well as in neuropil within the STG and at the junction of the superior oesophageal and stomatogastric nerves. The source of all histamine-like immunolabeling in the STG neuropil was one pair of neuronal somata, the previously identified inferior ventricular (IV) neurons, located in the supraoesophageal ganglion. These neurons also exhibited FLRFamide-like immunoreactivity. Activation of the IV neurons in the crab inhibited some pyloric and gastric mill neurons and, with inputs from the commissural ganglia eliminated, terminated both rhythms. Focal application of histamine had comparable effects. The actions of both applied histamine and IV neuron stimulation were blocked, reversibly, by the histamine type-2 receptor antagonist cimetidine. With the commissural ganglia connected to the STG, IV neuron stimulation elicited a longer-latency activation of commissural projection neurons which in turn modified the pyloric rhythm and activated the gastric mill rhythm. These results support the hypothesis that the histaminergic/peptidergic IV neurons are projection neurons with direct and indirect actions on the STG circuits of the crab C. borealis.
Modeling of InAs/GaAs quantum ring capacitance spectroscopy in the nonparabolic approximation

A three-dimensional model of $\mathrm{In}\mathrm{As}∕\mathrm{Ga}\mathrm{As}$ quantum rings based on a single sub-band approach with an energy dependence of the electron effective mass is used to describe the capacitance-voltage spectroscopy by Lorke et al. [Phys. Rev. Lett. 84, 2223 (2000)]. The confinement states energy problem is solved numerically using the finite elements method. Observed deviation of an electron effective mass from the bulk value is explained by the nonparabolic effect. Additional energy of the election ground state due to an external magnetic field is estimated and compared with the capacitance-voltage data. The model is also applied to describe the far-infrared measurements.
Pediatric microvascular reconstruction: a report from the Microvascular Committee.

Background Free tissue transfer is an integral part of modern head and neck surgery in the adult population. Its use in the pediatric population has not been well described. Recently, there has been an increase in the application of these techniques in the pediatric population. The morbidity of free tissue transfer in small pediatric patients and its effect on growth has not been well described. Objective To evaluate the utility of microvascular reconstruction techniques in the pediatric population. Study Design A consensus study was performed by the microvascular committee of the American Academy of Otolaryngology−Head and Neck Surgery. Thirty active microvascular surgeons reviewed their databases to find patients less than 21 years of age who underwent free tissue transfer. Results 49 free tissue transfers performed between 1999 and 2005. The mean age was 12.1 years (age range, 3−21). The types of flaps transferred were radial forearm (10), fibula (21), rectus abdominus (7), scapula (1), latissimus dorsi (3), groin (1), gracillus (4), and jejunum (2). Morbidity at the donor site was relatively minimal. Five patients developed wound breakdown. One of these required return to the operating room. Morbidity at the reconstructed site was also rare. Patients were followed for an average of 49 months (range, 1−131 months), and no problems were noted with growth at the donor or recipient sites. Conclusions Free flaps in the pediatric population have morbidity and survival similar to those in the adult population. Significance While indications differ from those in the adult population, these techniques are viable and valuable and should be considered in the pediatric reconstructive paradigm.
Comparative Perfomances of Two Commercial Samples of LiLSX Zeolite for Production of 90% Oxygen from Air by a Novel Rapid Pressure Swing Adsorption System

The performances of a novel rapid pressure swing adsorption system for continuous production of ˜ 90% O2 from a compressed air feed were experimentally studied using two different samples of pelletized LiLSX zeolite. Bed size factor (BSF) and O2 recovery (R) were compared as functions of total process cycle times. The optimum performance by the samples differed substantially—one exhibiting ˜ 30% smaller BSF and ˜ 6% higher R than the other, even though the adsorption isotherms and column dynamics for the pure gases were nearly identical. Column pressure drop during the desorption step was the cause.
Expression of neuropeptides in normal and abnormal appendices.

Abstract Background/Purpose: Increased neuroproliferation in the appendix associated with an increase in substance P (SP), vasoactive intestinal polypeptide (VIP), and growth-associated protein-43 (GAP-43) has been documented in appendices of adults with acute right lower quadrant (RLQ) abdominal pain and absence of gross or histologic signs of appendiceal inflammation. The authors tested whether these findings were present in children with RLQ pain and a normal appendix. Methods: Immunohistochemistry staining of paraffin-embedded appendices was performed with GAP-43, VIP, and SP. The positive control group included appendices with acute inflammation (group I, n=5); the negative control group included appendices removed incidentally (group II, n=5); and the experimental group included appendices from children suspected to have acute appendicitis without histologic signs of inflammation (group III, n=9). Results: Group I: VIP was strongly expressed in the nerve plexuses. The lamina propria and muscularis showed absent or minimal VIP expression. SP staining was strong in all plexuses and was moderate to strong in the muscularis. SP expression in the epithelium and lamina propria was difficult to quantify secondary to inflammation. Group II: VIP expression was essentially undetectable in the epithelium, lamina propria, and muscularis, and was moderate in the nerve plexuses. Mild SP staining was detected in the nerve plexuses of most specimens, and absent to mild staining was found in the epithelium and muscularis. However, one specimen strongly expressed SP in all layers. Group III: VIP expression was moderate to strong in the lamina propria and muscularis of nearly all specimens, and strong expression was found in all nerve plexuses. All but one specimen strongly expressed SP in plexuses. There was moderate to strong expression of SP in the epithelium, lamina propria, and muscularis in over 50% of specimens. The immunostaining for GAP-43 was very weak and nonspecific and did not help discriminate between the 3 study groups. Conclusions: Increased neuroproliferation in the lamina propria and muscularis was evident in patients with abdominal pain and normal appendices compared with appendices removed incidentally. The VIP and SP expression in these patients was similar or higher than that observed in patients with acute inflammation on histology. J Pediatr Surg 36:1222-1226. Copyright © 2001 by W.B. Saunders Company.
Fluorescence Quenching in Conjugated Polymers Blended with Reduced Graphitic Oxide

Conjugated polymers blended with graphene represent a possible approach for making organic bulk heterojunction solar cells. In this paper, the time-resolved fluorescence dynamics of poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) blended with graphene microsheets derived from chemically reduced graphitic oxide are studied. Both polymers exhibit strong quenching and shortened fluorescence lifetimes when mixed with graphene. The fluorescence quenching function takes the form of e−kQt1/2, where kQ is linearly proportional to the weight fraction of graphene in the blend. We consider two physical models to explain the origin of the fluorescence quenching. The first assumes that energy transfer occurs within a three-dimensional space to molecular scale defects within the graphene according to the standard Forster model with an energy transfer rate proportional to the donor−acceptor separation R−6. The second model assumes a quasi-two-dimensional en...
Synthesis of 1,4-disilacyclohexa-2,5-dienes

Abstract Title compounds of the type 2,3,5,6-tetraphenyl-1,4-di-X-1,4-di-Y-1,4-disilacyclohexa-2,5-diene wherein X=Y=NMe2 (4); X=NMe2, Y=Cl (cis, trans-5); X=NMe2, Y=Me [(trans)-6] and X=t-Bu, Y=Cl (trans-8) were synthesized from Si2(NMe2)5Cl, sym-Si2(NMe2)4Cl2, sym-Si2(NMe2)4Me2, and sym-Si2Cl4(t-Bu)2, respectively, in the presence of diphenylacetylene at 200 °C. Similarly the analogous title compound from the combination of 1-phenyl-1-propyne and Si2(NMe2)5Cl [X=Y=NMe2 (cis and trans-7) was synthesized. In all cases where cis/trans diastereomers could arise from two different silicon substituents (5, 6, 8) the trans isomer was the sole or dominant product. Evidence for the intermediacy of the silylene Si(NMe2)2 in these reactions was gained from a trapping experiment. Compound 4 upon treatment with SiCl4, SiBr4 or PI3 provided the corresponding 1,1,4,4-tetrahalo derivatives 9a–c, respectively. Treatment of 4 with MeOH or PhOH gave the 1,1,4,4-tetramethoxy and tetraphenoxy analogues 9d and 9e, respectively. The tetrachloro derivative 9a upon LAH reduction led to the corresponding tetrahydro compound 10, while the reaction of 9a with H2O gave the tetrahydroxy derivative 11. Allowing (trans)-6 to react with SiCl4 provided a ca. 1:1 cis/trans ratio of the derivative 12 in which X=Cl, Y=Me, and possible pathways that rationalize this loss of stereochemistry are proposed. Synthesis of trans-13 in which X=t-Bu, Y=H was achieved by LAH reduction of 8. All of the title compounds except 8 experience free phenyl rotation at room temperature. At −30 °C this rotation in 8 is essentially halted. The molecular structures of 4, 8, 9c, 9e, 10 and 13 were determined by X-ray crystallography.
The influence of moisture content and cooking on the screw pressing and prepressing of corn oil from corn germ

Samples of corn germ were obtained from a commercial corn wet mill (factory dried to about 3% moisture) and a commerical corn dry mill (undried, produced in the mill with about 13% moisture). The germ samples (200 g each) were cooked for various times in either a conventional oven at 180°C or a microwave oven at 1500 W. Bench-scale single screw pressing was then performed. With the dry milled corn germ, no oil was obtained from the uncooked germ. A maximal yield of about 5% oil [26% of total oil recovery (TOR), relative to hexane extraction] was obtained by cooking the dry-milled germ for 6.5 min in a conventional oven at 180°C before pressing. A maximal yield of about 7% oil (37% TOR) was obtained by cooking the dry-milled germ for 4.5 min in a microwave oven at 1500 W before pressing. With the wet-milled germ, yields of about 7% oil (18% TOR) were obtained with the uncooked germ and yields increased to a maximum of about 22% oil (56% TOR) by cooking in a conventional oven at 180°C for 5 min or a maximum of about 17% oil (44% TOR) by cooking for 4 min in a microwave oven at 1500 W. These results indicate that microwave and conventional oven cooking are both effective pretreatments before pressing. Microwave preheating resulted in higher oil yields with dry-milled germ, and conventional oven pretreatment resulted in higher oil yields with factory-dried wet-milled corn germ.
Illegitimate practices as legitimate participation: game cheat sites in a teen virtual world

Much research has described the various practices of gaining access and participation in multi-user game communities. Cheat websites that are a prominent part of the game culture and industry have been debated because of their illegitimate nature but received little attention in terms of their educational value. In this paper we analyze the cheat sites created by players for a teen virtual world called Whyville.net, which encourages youth ages 8-16 to participate in a range of social activities and play casual science games. Analysis of a sample of 257 cheat sites resulted in typologies for both the cheats and sites in terms of quality and quantity of science content. A case study of an especially active cheat site and analysis of player-written articles in Whyville's newspaper illuminate the illegitimate and legitimate aspects of cheating in this virtual world. Implications of these findings as cultural artifacts of the game community and as guides for designing informal online learning activities are discussed.
Construct validity of cognitive-behavioral treatments for intimate and social loneliness

The purpose of this study was to compare the effects of two cognitive-behavioral interventions whose contents were matched to distinct types of loneliness (intimate and social) derived from empirical and theoretical literature and from a factor analysis of theRevised UCLA Loneliness Scale. Screened participants were assessed on measures varying in theoretical relevance to the treatment conditions. The hypotheses were that each treatment would favorably influence measures of high theoretical relevance (e.g., the social loneliness treatment would reflect changes on measures of social loneliness) and would have comparatively lesser effects on measures of lower theoretical relevance. Analysis of Covariance on pre-, post- and follow-up data indicated that the social loneliness treatment significantly decreased both intimate and social loneliness in the absence of differences on control variables. Issues relevant to the construct validity of the distinct treatments are discussed.
Cycling of elements in duckweed (Lemna perpusilla) in an ash settling basin and swamp drainage system

Abstract Duckweed ( Lemna perpusilla Torrey), inhabiting a stream-swamp drainage system that received high quantities of coal ash or thermal discharges from a fossil fuel power plant, was the only abundantly occurring macrophyte. For a period of 1 yr, accumulations of 22 elements in components of this system (water, sediments and duckweed) were determined at six stations using neutron activation analysis. Abiotic processes (e.g. settling, solution) were important in cycling some elements including heavy metals, while some potentially toxic elements (e.g. Hg and Se) were bioconcentrated by duckweed. In those stations where ash influence was greater in water and sediments, elemental uptake by duckweed was also higher. Approximately 1200 m 2 of swamp area was necessary to facilitate the removal of most ash influence. The use of duckweed as food may be a potential source of bioaccumulation or biomagnification of toxic elements by migratory wildfowl that frequent ash-impacted drainage systems.
A bibliometric analysis of pharmaceutical research

Abstract This study examines pharmaceutical research from a bibliometric perspective. It finds that there are bibliometric correlates of successful pharmaceutical research, in particular, the number and proportion of star (highly cited) clinical medical articles. The research also reveals that pharmaceutical company research reported in basic biomedical research journals is very highly cited, on a par with NIH supported medical school research. The policy implications of this are discussed. In addition, the pharmaceutical output (approved new drugs)/input (R&D budget) measures developed permit a ranking and characterization of the research performance of 24 major pharmaceutical companies.
Abstract 2389: uPA and uPAR siRNA inhibits angiogenesis by blocking nuclear localization of angiogenin and angiopoietin1 signaling in glioblastoma cell lines

Transcriptional inactivation of uPA and uPAR system in the glioblastoma cell line SNB19 inhibited angiogenesis both in vitro and in vivo. To decipher this mechanism and extend our studies to other glioblastoma cell lines, U87MG and U87 SPARC-overexpressing cell lines were subjected to uPA, uPAR and U2 (bicistronic construct against uPA and uPAR) downregulation by siRNA. In the present study, the bicistronic construct against uPA and uPAR caused significant inhibition of angiogenesis by in vitro angiogenesis assay and in vivo dorsal skin fold chamber models in both cell lines. Increased apoptosis was seen in siRNA downregulated gliomablastoma cells when compared with control cells by FACS analysis. MTT assay revealed significant inhibition of proliferation by U2 siRNA treatment in both cell lines. Transfection with siRNA against uPA and uPAR in co-cultures of glioma cells with endothelial cells showed significant inhibition of angiopoeitin1, IL-6, GRO and GM-CSF while SPARC-overexpressing U87 cells had decreased secretion of angiogenin, GRO, MCP-1, PDGFBB, VEGF and angiopoietin1 by protein array analysis. Bicistronic construct showed decreased levels of angiogenin by ELISA and Western blot in endothelial cells and in cocultures with cancer cells. Transcriptional inactivation of uPA and uPAR showed significant downregulation of angiogenin-induced phosphorylation of ERK, JNK and Akt signaling in endothelial cells. Nuclear translocation of angiogenin in semi-confluent human umbilical vein endothelial cells treated with conditioned medium from siRNA-transfected U87 SPARC-overexpressing cells was inhibited as shown by Western blot and immunofluorescence analyses. Conditioned medium from U87MG and U87 SPARC-overexpressing cells transfected with uPA, uPAR and U2 siRNA plasmids significantly inhibited the phosphorylation of Tie2 receptor in endothelial cells. uPA and uPAR downregulation significantly downregulated MMP-2 levels by gelatin zymography in co-cultures and in single cultures of cancer cells. Matrix metalloproteinase array analysis showed significant inhibition of MMP-3 in co-cultures of U2-transfected SPARC-overexpressing glioma cells. Overall, our results suggest that the simultaneous downregulation of uPA and uPAR inhibits angiogenesis by inhibition of nuclear localization of angiogenin, angiopoeitin 1 signaling and MMP-2 downregulation in endothelial cells. In summary, these results identify novel mechanisms by which the bicistronic construct against uPA and uPAR inhibits angiogenesis, thereby suggesting the potential use of U2 as an anti-angiogenic agent against glioblastoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2389.
High-field magnetoresistance of metals by Kubo-Mott formula☆

Abstract A completely quantum-mechanical calculation of the galvanomagnetic tensor σμν (including magnetic breakdown effects) for nearly free-electron (NFE) metals in strong dc magnetic fields (ωcτ > 1) is presented. The method employed is the Kubo formula for σμν in a particularly convenient form introduced recently by Mott: this involves the matrix elements, 〈ψk′ | j | ψk〉, of the current operator, j = ( e m )(−i h ∇ + e A c ) , where curl A defines the applied field H, and ψk is the one-electron wave function which we determine to first order in a weak pseudopotential, V, by NFE perturbation of Landau (harmonic oscillator) eigenstates for a free electron in a magnetic field. It is shown that the contributions to such matrix elements of the current can be represented by Feynman graphs for a second-order scattering process which involves an electron-coulomb vertex (given by V) and the emission or absorption of a fictitious excitation (characterized by a vertex given by a current ( e h m )( A n π ) 1 2 , An being the area of the quantized cyclotron orbit in k-space, and an energy transfer of amount h ω c in the plane normal to H). For a pseudopotential, V, having any number of Fourier components, the method enables us to include phase coherence exactly in the Pippard network of electron orbits coupled by magnetic breakdown, and to exhibit three types of oscillatory effects due to phase coherence, electron density of states (Shubnikov-de Haas effect) and the so-called “zone” oscillations. Analytical results are given for the linear chain and the hexagonal network and compared with experiment.
ON THE ROTATIONAL BEHAVIOR OF NEREID

We have conducted a set of numerical simulations of the combined orbital and rotational motion of Neptune's moon Nereid to study its rotational behavior under the influence of gravitational torques from Neptune. Due to the high eccentricity of its orbit, and the fact that the gravitational torque from Neptune varies as r ?3, Nereid experiences a large impulsive torque during each periapsis passage. If Nereid is a prolate body, then these kicks induce oscillations in the orientation of its spin axis that is seen to be a coning motion of modulating amplitude. We have proposed that these modulations may be responsible for the long-term photometric variability of Nereid as reported by Schaefer et?al. and others.
Altered mRNA expression of the neuronal nitric oxide synthase gene in Hirschsprung's disease

Abstract Nitric oxide has been described as an inhibitory neurotransmitter to mediate smooth muscle relaxation in the mammalian gastrointestinal tract. The enzyme neuronal nitric oxide synthase (NOS) catalyzes the formation of NO. The authors examined the expression of neuronal NOS gene at the mRNA level in intestinal specimens from seven patients who had Hirschsprung's disease (HD) using reverse transcription polymerase chain reaction (RT-PCR) technique. With 35 cycles of PCR reaction, substantial signals of neuronal NOS mRNA were observed in the ganglionic bowel in all seven patients, whereas in the aganglionic bowel, neuronal NOS signals were weak in three patients, and undetectable in four patients. By increasing the PCR cycle to 40 cycles, barely detectable signals were observed in two of the latter four patients. Semiquantitative analysis in the three patients who showed weak signals with 35 cycles of PCR indicated that neuronal NOS mRNA expression in aganglionic bowel was decreased at least 150 to 1100 of the level of expressed in ganglionic bowel. Because absence or low level of expression of neuronal NOS mRNA may lead to impaired production of NO, our observations suggest that motility dysfunction in HD may be as a result of markedly decreased or no expression of the neuronal NOS gene at the mRNA level.
Partitioning a Daily Mechanical Stimulus into Discrete Loading Bouts Improves the Osteogenic Response to Loading

A single 3-minute bout of mechanical loading increases bone formation in the rat tibia. We hypothesized that more frequent, shorter loading bouts would elicit a greater osteogenic response than a single 3-minute bout. The right tibias of 36 adult female Sprague-Dawley rats were subjected to 360 bending cycles per day of a 54 N force delivered in 1, 2, 4, or 6 bouts on each of the 3 loading days. Rats in the 6-bouts/day group received 60 bending cycles per bout (60 x 6); rats in the 4-bouts/day group received 90 bending cycles per bout (90 x 4); the 2- and 1-bouts/day groups received 180 and 360 bending cycles per bout, respectively (180 x 2 and 360 x 1). A nonloaded, age-matched control group (0 x 0) and two sham-bending groups (60 x 6 and 360 x 1) also were included. Fluorochrome labeling revealed a 10-fold increase in endocortical lamellar bone formation rate (BFR/bone surface [BS]) in the right tibia versus the left (nonloaded) side in the 60 x 6 bending group. Endocortical BFR/BS in the right tibia of the 4-, 2-, and 1-bout bending groups exhibited 8-, 4-, and 4-fold increases, respectively, over the control side. Relative (right minus left) values for endocortical BFR/BS, mineralizing surface (MS/BS), and mineral apposition rate (MAR) were 65-94% greater in the 90 x 4 and 60 x 6 bending groups compared to the 360 x 1 bending group. Sham-bending tibias exhibited relative endocortical bone formation values similar to those collected from the control (0 x 0) group. The data show that 360 daily loading cycles applied at intervals of 60 x 6 or 90 x 4 represent a more osteogenic stimulus than 360 cycles applied all at once, and that mechanical loading is more osteogenic when divided into discrete loading bouts. Presumably, bone cells become increasingly "deaf" to the mechanical stimulus as loading cycles persist uninterrupted, and by allowing a rest period between loading bouts, the osteogenic effectiveness of subsequent cycles can be increased.
Inhibition of gap junctional intercellular communication in heptachlor- and heptachlor epoxide-treated normal human breast epithelial cells

Based on the concern of organochlorides in the environment and in human tissue, this study was designed to determine whether various noncytotoxic levels of heptachlor and heptachlor epoxide could inhibit, reversibly, gap junctional intercellular communication in human breast epithelial cells (HBEC). Cytotoxicity and gap junctional intercellular communication (GJIC) were evaluated by lactate dehydrogenase assay and fluorescence redistribution after photobleaching analysis, respectively. Both heptachlor and heptachlor epoxide were noncytotoxic up to 10 μg/ml. At this concentration, heptachlor and heptachlor epoxide inhibited GJIC of normal human breast epithelial cells after 1 h treatment. Within a 24 h treatment with heptachlor and heptachlor epoxide at 10 μg/ml, recovery of GJIC had not returned. GJIC completely recovered after a 12 h treatment of 1 μg/ml heptachlor epoxide, but it did not recover after a 24 h treatment of 1 μg/ml heptachlor. RT-PCR and Western blots were analyzed to determine whether the heptachlor or heptachlor epoxide might have altered the steady-state levels of gap junction mRNA and/or connexin protein levels or phosphorylation state. No significant difference in the level of connexin 43 (Cx43) message between control and heptachlor-treated cells was observed. Western blot analyses showed hypophosphorylation patterns in cells treated with 10 μg/ml heptachlor and heptachlor epoxide for 1 h with no recovery within 24 h. Immunostaining of Cx43 protein in normal HBEC indicated that heptachlor and heptachlor epoxide caused a loss of Cx43 from the cell membranes at noncytotoxic dose levels. Taken together, these results suggest that heptachlor and heptachlor epoxide can alter GJIC at the post-translational level, and that, under the conditions of exceeding a threshold concentration in the breast tissue containing ‘initiated’ cells for a long time and not being counteracted by anti-tumor-promoting chemicals, they could act as breast tumor promoters.
Familial prostatic cancer risk and low testosterone.

We investigated whether familial factors influence 1) the incidence of prostatic cancer and 2) the plasma content of sex steroids. A 4-fold higher relative risk for the development of prostatic cancer was observed for brothers (n = 257) of prostatic cancer cases (n = 150) compared to their brothers-in-law (n = 202) and males in the general population of the state of Utah. The intraclass correlation for plasma testosterone content [intraclass correlation coefficient (r1) = 0.51; P < 0.01[ and the apparent free testosterone concentration (r1 = 0.54; P < 0.01) were highly significant in nonendocrinologically treated cases and their brothers. Further, sons and their fathers had significant intraclass correlations for both plasma dihydrotestosterone (r1 = 0.83; P < 0.01) and the ratio of testosterone to dihydrotestosterone (r1 = 0.46; P < 0.05). Probands and their brothers, and sons of the patients with the disease had significantly lower plasma testosterone levels than controls of comparable age. This is the ...
Do Models and Observations Disagree on the Rainfall Response to Global Warming

Abstract Recently analyzed satellite-derived global precipitation datasets from 1987 to 2006 indicate an increase in global-mean precipitation of 1.1%–1.4% decade−1. This trend corresponds to a hydrological sensitivity (HS) of 7% K−1 of global warming, which is close to the Clausius–Clapeyron (CC) rate expected from the increase in saturation water vapor pressure with temperature. Analysis of two available global ocean evaporation datasets confirms this observed intensification of the atmospheric water cycle. The observed hydrological sensitivity over the past 20-yr period is higher by a factor of 5 than the average HS of 1.4% K−1 simulated in state-of-the-art coupled atmosphere–ocean climate models for the twentieth and twenty-first centuries. However, the analysis shows that the interdecadal variability in HS in the models is high—in particular in the twentieth-century runs, which are forced by both increasing greenhouse gas (GHG) and tropospheric aerosol concentrations. About 12% of the 20-yr time inte...
Epidermal growth factor-dependent cyclooxygenase-2 induction in gliomas requires protein kinase C-delta.

Earlier, we showed that epidermal growth factor receptor (EGFR) signaling in human glioma cells increased cyclooxygenase-2 (COX-2) expression through p38-mitogen-activated protein kinase (MAPK)-dependent activation of the Sp family of transcription factors. Further mechanistic details of EGFR-dependent induction of COX-2 expression in glioma cells remained elusive. Protein kinase Cs (PKCs) comprise a family of serine-threonine kinases that are major mediators of signaling from receptor tyrosine kinases. Here, we report that PKC-δ, a novel PKC isoform, plays a role in EGF-dependent COX-2 induction in human glioma cells. Pharmacological inhibition and genetic silencing (through siRNA or dominant-negative expression) of PKC-δ confirm a role for this PKC isoform in EGF-dependent COX-2 induction. Overexpression of a functional PKC-δ enhanced COX-2 expression indicating that PKC-δ is not only necessary but also sufficient to regulate COX-2 levels. Inhibition of p38-MAPK pharmacologically or with siRNA further shows that p38-MAPK is required for activation of PKC-δ by EGF while inhibition of PKC-δ had no discernible effects on p38-MAPK activation. Finally, EGF stimulation promotes physical interactions between PKC-δ and Sp1 resulting in phosphorylation and nuclear localization of this transcription factor. These data provide the first evidence that PKC-δ is a critical link between p38-MAPK and Sp1-dependent COX-2 expression in human glioma cells.
Serum Inhibitors of Asaian Strains of Influenza Virus

During the past several months we have been studying the serological behaviour of various Asian influenza strains, with particular reference to their sensitivity to non-specific serum haemagglutination inhibition (HI). Of the five strains studied, four were highly sensitive, one moderately so, to human serum inhibitor in early egg passages. Sensitivity was lost abruptly on continued passage in the allantoic cavity in four of the strains. More detailed studies on one of the strains, A/Roberge, have shown that loss of sensitivity to inhibition of haemagglutination is correlated with (a) resistance in ovo to the neutrallizing activity of normal horse serum and (b) increased enzymatic activity as measured by rapidity of elution from chicken red blood cells.