cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal stability of bias point of packaged linear modulators in lithium niobate

The thermal stability of the bias point of packaged, passively biased, X-cut LiNbO/sub 3/ interferometric modulators is described. Absolute stability is assessed and a comparison is made of stability before and after laser ablation adjustment used to tune the bias point to linear operation (90/spl deg/ phase angle). Ablation is shown to be successful in setting the bias angle to /spl plusmn/1/spl deg/ of the desired value. The angle remained stable to a total variation of <5/spl deg/ over -25-+42/spl deg/C both before and after ablation. All the observed angular changes with temperature were in the range 0.02-0.09 deg//spl deg/C. The effect of humidity in the package on modulator stability is characterized and then minimized for the actual devices.
Diastereoselective synthesis of a hydroxamate containing bicyclo-[3.2.0] β-lactam aminal via ruthenium alkene isomerization and Pd(II)-catalyzed oxidative amidation

Abstract With antibiotic resistance on the rise, the need for new medicinal scaffolds is needed. The synthesis of an aminal bicyclic β-lactam core is described. The key synthetic step is Pd(II)-catalyzed oxidative amidation. The product is a single diastereomer, confirmed by X-ray crystallography.
A review of statistical methods for expression quantitative trait loci mapping

With high-throughput technologies now widely available, investigators can easily measure thousands of phenotypes for quantitative trait loci (QTL) mapping. Microarray measurements are particularly amenable to QTL mapping, as evidenced by a number of recent studies demonstrating utility across a broad range of biological endeavors. The early success stories have impelled a rapid increase in both the number and complexity of expression QTL (eQTL) experiments. Consequently, there is a need to consider the statistical principles involved in the design and analysis of these experiments and the methods currently being used. In this article we review these principles and methods and discuss the open questions most likely to yield significant progress toward increasing the amount of meaningful information obtained from eQTL mapping experiments.
Defects and ion-solid interactions in silicon carbide

Atomic-level simulations are used to determine defect production, cascade-overlap effects, and defect migration energies in SiC. Energetic C and Si collision cascades primarily produce single interstitials, mono-vacancies, antisite defects, and small defect clusters, while amorphous clusters are produced within 25% of Au cascades. Cascade overlap results in defect stimulated cluster growth that drives the amorphization process. The good agreement of disordering behavior and changes in volume and elastic modulus obtained computationally and experimentally provides atomic-level interpretation of experimentally observed features. Simulations indicate that close-pair recombination activation energies range from 0.24 to 0.38 eV, and long-range migration energies for interstitials and vacancies are determined.
Light-scattering and ultrastructure of healed penetrating corneal wounds.

Purpose To investigate quantitatively for the first time the relationship between light scattering and ultrastructure of semi-transparent scars resulting from penetrating wounds in rabbit cornea.
Detection of the water-soluble fraction of crude oil by the blue crab, Callinectes sapidus

Abstract The ability of the blue crab, Callinectes sapidus, to detect petroleum hydrocarbons was measured with behavioural techniques. When presented with a water-soluble fraction of Prudhoe Bay crude oil, blue crabs abruptly changed antennular orientation, began rhythmic beating of the maxillipedal flagellae, and increased antennular flicking rate. The threshold concentration at which 50% of the crabs detected the water-soluble fraction was 2 × 10−6 mg/litre. The blue crab apparently can readily detect petroleum hydrocarbons at concentrations found in chronically polluted areas as well as oil spill situations.
Symbols and selectivity: A statistical analysis of native american medical ethnobotany

Abstract Native Americans use a wide range of plants medicinally. Many of these plants have profound meaning to their users. Does this mean, as some assert, that tribal medicine is “all placebo”? Since the essential character of meaning is the arbitrariness of the sign, then insofar as this medicine is symbolic, the plants used medicinally will be a random representation of plants available in nature. Several regression analyses of plants used by native Americans on plants available to them indicate substantial selectivity in plant use. Native American medical ethnobotany is not only placebo medicine.
Effects of dissolved oxygen on hybridoma cell growth, metabolism, and antibody production kinetics in continuous culture.

The effects of dissolved oxygen concentration (DO) on hybridoma cell physiology were examined in a continuous stirred tank bioreactor with a murine hybridoma cell line (167.4G5.3). Dissolved oxygen concentration was varied between 0% and 100% air saturation. Cell growth and viability, carbohydrate, amino acid, and energy metabolism, oxygen uptake, and antibody production rates were investigated. Cell growth was inhibited at both high and low DO. Cells could grow at 0% DO and maintain viability under a nitrogen atmosphere. Cell viability was higher at low DO. Glucose, glutamine, and oxygen consumption rates changed little at DO above 1 % air saturation. However, the metabolic uptake rates changed below 1 % DO, where growth became oxygen limited, and a Km value of 0.6 % DO was obtained for the specific oxygen uptake rate. The metabolic rates of glucose, glutamine, lactate, and ammonia increased 2-3-fold as the DO dropped from 1% to 0%. Amino acid metabolism followed the same general pattern as that of glutamine and glucose. Alanine was the only amino acid produced. The consumption rates of amino acids changed little above 1% DO, but under anaerobic conditions the consumption rates of all amino acids increased severalfold. Cells obtained most of their metabolic energy from glutamine oxidation except under oxygen limitation, when glucose provided most of the energy. The calculated ATP production rate was only slightly influenced by DO and rose at 0% DO. Antibody concentration was highest at 35% DO, while the specific antibody production rate was insensitive to DO.
The role of grade sensitivity in explaining the gender imbalance in undergraduate economics

Abstract There is a gender imbalance in undergraduate economics departments with most departments educating a strong majority of young men. This imbalance has led many economists to ponder the question of why relatively few women choose to take courses and major in economics. Our hypothesis is that the gender imbalance in undergraduate economics, particularly at institutions with traditional liberal arts curriculums, is partly explained by women's greater sensitivity to grades, particularly lower grades. Students choose their majors based on both their interests and their abilities. The literature indicates that the grade a student receives in an introductory class relative to grades received in other departments is one of the strongest predictors of whether or not the student chooses to enroll in more courses in the discipline. However, our hypothesis is that men who take economics courses are less responsive to this signal than are women. As a result, men who do poorly in economics are more likely to continue in the major. Women who do poorly, in contrast, are more likely to abandon economics and pursue a different major. Our results, generated from 16 years of data from a liberal arts college where economics is one of the most popular majors, support this hypothesis. The overall economics GPA for female majors is significantly higher than that for males and male students dominate the bottom of the grade distribution. Finally, results from the estimation of a series of selection models of the decision to take more economics courses indicate that, holding other characteristics constant, women are more responsive to the relative grade received than are men.
Combined pre- and postnatal ethanol exposure alters the development of Bergmann glia in rat cerebellum.

Abstract The development and maturation of Bergmann glial cells in the rat cerebellum was evaluated on postnatal day 15 by glial fibrillary acidic protein (GFAP) immunocytochemistry, following combined gestational and 10-day postnatal ethanol exposure (a full three trimester human equivalency). GFAP-positive Bergmann glial fibers of lobules I, III, VIb, VII and X of the cerebellar vermis were examined and counted in the molecular layer (ML), the external granular layer (EGL) and the external limiting membrane (ELM). Ethanol exposure reduced: 1. (1) the number of GFAP-positive fibers (per unit length of folia surface) at all three levels; 2. (2) the percentage of mature fibers; and 3. (3) the cross-sectional area in all lobules examined. When data from the five lobules were pooled, there were 7% fewer GFAP-positive fibers in the ML, 15% fewer in the EGL and 20% fewer in the ELM; the percentage of mature fibers was reduced by 16%; and the cross-sectional areas of lobules were reduced by 16%. The altered development of Bergmann glia could be one of the factors causing delayed migration of granular neurons and reductions in the number of granule cells reported in other studies following developmental ethanol exposures and could help to explain some of the motor dysfunctions reported in FAS victims.
PRoP: personal roving presence

Current internet applications leave our physical presence and our real-world environment behind. This paper describes the development of several simple, inexpensive, internet-controlled, untethered tele-robots or PRoPs (Personal Roving Presences) to provide the sensation of teleembodiment in a remote real space. These devices support at least video and two-way audio as well as mobility through the remote space they inhabit. The physical telerobot serves both as an extension of its operator and as a visible, mobile entity with which other people can interact. PRoPs enable their users to perform a wide gamut of human activities in the remote space, such as wandering around, conversing with people, hanging out, pointing, examining objects, reading, and making simple gestures.
Aggregate Replication, a Factor in the Growth of Cancer

Microscopically, most clinical carcinomas appear as aggregates of neoplastic cells in a matrix of connective tissue. As the tumor grows, increasing numbers of nests of cells are seen. Studies in which matrix tissue culture techniques are used implicate factors intrinsic to the aggregate in the continuing propagation of new nests of cells.
Dietary α-tocopheryl acetate contributes to lipid stability in cooked beef

Lipid oxidation was investigated in cooked gluteus medius from Holstein steers fed diets including four levels of α-tocopheryl acetate (0, 250, 500 and 2,000 mg/steer daily) for 42 or 126 days. Alpha-tocopherol (vitamin E) concentrations increased in fresh and cooked muscle due to level and duration of supplementation (P<0.01). Cooking did not affect α-tocopherol concentration in the muscle. Dietary α-tocopheryl acetate delayed (P<0.01) accumulation of lipid oxidation products in cooked muscle during 6 days of display at 4 o C. Daily supplementation of 500 mg α-tocopheryl acetate for 126 days resulted in 3.4 μg α-tocopherol/g cooked gluteus medius
EXPERIMENTAL AND NUMERICAL STUDIES OF MICROSPHERE OBLIQUE IMPACT WITH PLANAR SURFACES

Abstract Oblique impact experiments have been carried out with stainless-steel microspheres and silicon surfaces under a range of impact velocities from 0.45 to 1.90 m s−1 and different incident angles. When the normal velocity component for oblique impact is less than the capture velocity as seen for normal impact, no capture was observed. The experimental results also reveal that the pattern of impulse ratio variation with incident angle varies with different initial impact velocities. Furthermore, the measured coefficient of restitution values can be predicted by a dynamic simulation model, and the measured impulse ratios can be matched if the microspheres are assumed to have initial angular velocities.
On the impossibility of certain Moore graphs

A Moore graph of type (d, k) is a regular graph of degree d, diameter k, and girth 2k + 1. By counting the cycles of length 2k + 1 and 2k + 2 of a Moore graph, it is shown that there are no Moore graphs of type (d, k) for d = 3, 4, 5, 6, 8 and 3 < k ≤ 300 except possibly for type (5, 7). It is shown that there are no Moore graphs of type (3, k) when 3 ≤ k < ∞ and 2k + 1 is prime.
ATP synthetase: A mixture of factor a and avidin sensitive ATP-Pi exchange activity☆

Abstract The ATP-Pi exchange activity of highly purified preparations of ‘ATP synthetase’ was inhibited by F1-antiserum, Pullman inhibitor, azide and also by avidin (See You and Hatefi, 1973) . The inhibition produced by the first three was relieved in the presence of ADP, and the avidin sensitivity was lost on pretreatment on the avidin with biotin. It is concluded that the ATP-Pi exchange resulted from the combined action of Factor A and a contaminating avidin-sensitive enzyme. The ADP necessary for the exchange reaction catalyzed by the latter was generated by the ATPase activity of Factor A.
ISOLATION OF RIBOSOMES FROM CYSTS OF ENTAMOEBA INVADENS

A reproducible method for the preparation of 75S ribosomes from cysts of Entamoeba invadens is presented. The method depends on the inactivation of the cyst's ribonuclease by high levels of Bentonite. The ribosomes are found to be extremely sensitive to ribonuclease, and to be stabilized by the addition of manganous and calcium ions to the magnesium customarily employed. Reasons are given for equating these ribosomes with the particles of which the crystalline chromatoid bodies are made.
A photoionization study of the formation of NO2 + by reaction of excited O2 + ions with NO

The production of CO2(+) by the ion-molecule reaction O2(+) + CO yields CO2(+) + O has been investigated using a photoionization mass spectrometer. The photoionization efficiency for production of CO2(+) by this reaction was measured from threshold at 924 A (13.42 eV) to 650 A (19.07 eV). The appearance potential corresponds to reaction of ground vibronic O2(+) ions formed in the nu-prime = 6 level. The high-vibrational-level ions of the ground ionic state are most likely produced by autoionization of O2. At wavelengths shorter than 760 A, there is a large increase in the reaction cross section associated with formation of ions in the metastable state. The peak reaction cross section occurs at 720 A.
Structured Singular Value Synthesis Design Example: Rocket Stabilization

The structured singular value synthesis methodology is applied to generate a stabilization control law for a rocket ascending through the earth's atmosphere. The control law stabilizes the inherent unstable pitching motions of the elastic vehicle by vectoring the thrust in response to motion sensed by a pitch rate gyroscope. There is Significant structured uncertainty in the modeled elastic and rigid body dynamics. The control law for the rocket stabilization example employs classical phase stabilization for the lowest elastic mode and gain stabilization for the higher frequency modes. The similarities and differences of this control law compared to a more traditional control law are discussed.
IL-1α increases arachidonyl-COA: Lysophospholipid acyltransferase activity and stimulates [3H] arachidonate incorporation into phospholipids in rat mesangial cells

Abstract The proinflammatory cytokine interleukin-1α is a potent stimulus of prostaglandin synthesis. We have previously shown that IL-1 amplifies mesangial cell prostaglandin synthesis by inducing synthesis of a non-pancreatic phospholipase A 2 . Phospholipase A 2 activation results in the formation of lysophospholipids and free fatty acids. We now investigate the effects of IL-1α on reacylation of lysophospholipids. Incubations with IL-1α for 24 hours significantly stimulated mesangial cell [ 3 H] arachidonic acid incorporation but not [ 3 H] oleic acid incorporation into phosphatidylinositol and phosphatidylethanolamine. Lysophospholipid acyltransferase activity was measured in vitro. Cytokine treatment increased enzyme activity when lysophosphatidylcholine, lysophosphatidylethanolamine and lysophosphatidylinositol were used as exogenous substrates. We conclude that IL-1 promotes cellular phospholipid remodeling by stimulating the deacylation and reacylation of phospholipids.
Modification of Porous Silicon Surfaces with Activated Ester Monolayers

A series of activated esters of undecylenic acid with activated ester end groups (3-nitrophenyl, N-succinimidyl, S-ethyl, and 2,2,2-trifluoroethyl) have been synthesized and covalently linked to a porous silicon (PSi) surface via a thermal hydrosilylation reaction. Diffuse reflectance infrared Fourier transform (DRIFT) or transmission FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to characterize the monolayers and to follow the course of reactions with primary amines in aqueous solution. It was found that the reaction of the 3-nitrophenyl undecylenate with the PSi surface resulted in significant oxidation of the surface. A control reaction with nitrobenzene confirmed that the arylnitro group was responsible for the surface oxidation and grafting of the nitroaromatic on the surface via a Si−O−N linkage. The N-succinimidyl (NHS) and thioethyl activated ester-modified surfaces formed monolayers with no apparent oxidation of the PSi surface. However, we find that the hydrophobic end g...
High-throughput thermal conductivity measurements of nickel solid solutions and the applicability of the Wiedemann–Franz law

Abstract Thermal conductivity mapping with a spatial resolution of 3 μm and an acquisition speed of 3 points per second has been applied to binary Ni(Cr), Ni(Pd), Ni(Pt), Ni(Rh) and Ni(Ru) solid solutions to test the applicability of the Smith–Palmer equation and the Wiedemann–Franz law to Ni alloys. The lattice thermal conductivity of pure Ni and Ni(Pd) alloys is calculated by molecular dynamics. After subtracting the lattice component from the total thermal conductivity, the electronic thermal conductivity of pure Ni is 25% smaller than that predicted from the Wiedemann–Franz law. With the addition of solutes of Pt and Rh, the deviation from the Wiedemann–Franz law decreases. However, the negative deviation of the electronic thermal conductivity of Ni(Pd) alloys from the Wiedemann–Franz law increases slightly to 29% when the Pd concentration is 40 at.%. The Smith–Palmer equation is not a generally reliable method for predicting the thermal conductivity of Ni solid solution alloys from measurements of the electrical conductivity.
ROOM TEMPERATURE CREEP OF TI-6AL-4V

Recent investigations have shown both that Ti-6A1-4V does and does not exhibit room temperature creep at low stress. In the present investigation three different microstructures (α β anneal, recrystallization anneal and β anneal) of Ti-6A1-4V were examined under dead weight torsional loading. The loading sequence was forward, reverse and second forward loading. It was concluded that even at a stress level well below the yield stress the alloy exhibits creep in forward loading and increased creep strain in reverse loading and second forward loading. Furthermore the rate of creep at constant stress was different in different microstructures of the alloy; the maximum creep rate occurred with the recrystallization anneal and the minimum creep rate occurred with the β anneal. At the maximum stress in forward loading there appeared to be a change in creep mechanism.
Role of GTP in protein synthesis: Interaction of GTP with soluble transfer factors from E. coli

Abstract Using partially purified preparations of the soluble transfer factors Ts and Tu from E. coli it has been possible to study the kinetics of the formation of a GTP-protein complex. The data show that Ts affects the rate of complex formation and that Tu determines the amount, or extent, of the GTP complex. In addition, two protein factors that possess Ts activity have been separated by Sephadex G-100 chromatography. One of these (Ts1) exhibits a different Chromatographic pattern on Sephadex G-100 in the presence of GTP.
Monitoring the surface adsorption of cyanine dyes via evanescent wave-excited fluorescence

By confining light from a diode laser within a solid planar waveguide in contact with a liquid sample, an electromagnetic field is produced which extends into the solution for a distance of several hundred nanometers. This `evanescent wave' has all the properties (e.g. power, wavelength, etc.) of light propagating freely through the solution, and as such can excite fluorescence if suitable fluorophores are present. The evanescent wave technique has the advantage of being confined to the very small volume found within 100 - 200 nm of the waveguide surface, so that molecules in the bulk solution, away from the waveguide, do not experience the evanescent wave field. Evanescent wave excited fluorescence is therefore a spatially-specific probe of surface phenomena at the liquid-solid interface.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The ARCO decision: Inroads into the per se rule under Section 1 of the Sherman Act

In this study, the author analyzes the 1990 U.S. Supreme Court decision inAtlantic Richfield Company vs. USA Petroleum Company approving Atlantic Richfield’s maximum pricing plan improsed on its distributors (despite the Court’s recognition that theper se rule forbade such schemes). Theper se rule had been one of the last substantial measures of effective antitrust policy administered by enforcement authorities and the courts, perhaps even more fundamental than scrutiny of proposed mergers and predatory practices. That principle has been weakened by the ARCO decision. The author addresses some of the likely consequences of the ascendancy of the Chicago School and the NeoClassical theory generally in antitrust interpretation.
The Asthma Control and Communication Instrument: a clinical tool developed for ethnically diverse populations.

Background Lower levels of quality asthma care among racially diverse populations might be due to inaccurate disease status assessments. The Asthma Control and Communication Instrument (ACCI) is a new tool that captures patient report of disease status during routine care. Objective We sought to test the ACCI's psychometric properties in a racially diverse population. Methods We performed a cross-sectional study. Subjects were recruited from specialist and generalist urban outpatient clinics. The ACCI and measures of asthma control, quality of life, lung function, and specialist rating of asthma status were collected. Four ACCI domains were separately validated: Acute Care, Bother, Control, and Direction. Principal component analysis, internal consistency, concurrent, discriminative, known-groups validity, and accuracy were evaluated. Results Two hundred seventy asthmatic patients (77% female subjects, 55% black) participated. ACCI Control domain internal consistency was 0.80. ACCI Bother, Control, and Direction domains showed strong concurrent validity with asthma control and quality-of-life measures (all P Conclusion The ACCI is a promising clinical tool that measures asthma disease status during routine health care and is valid for use in both black and white populations.
Lysophosphatidylserine enhances the transfer of 22:6n3 to lysophosphatidic acid in rat brain microsomes

Although the acyl groups of phosphatidylserine in brain are uniquely enriched in docosahexaenoic acid (22:6n3), the mechanism for this enrichment is not well understood. When rat brain homogenates and microsomes were incubated in the presence of lysophosphatidylserine (LPS) together with [14C]22:6n3 and cofactors for activation to its acylCoA, very little radioactivity was incorporated into phosphatidylserine (PS). On the other hand, [14C]20:4n6 was more actively incorporated into PS. Addition of LPS (1-10 uM), however, resulted in a 2-5 fold enhancement of the transfer of labeled 22:6n3 and 20:4n6 to phosphatidic acid (PA). Kinetic analysis indicated the ability of LPS to lower the Km and increase the Vmax of the lysophosphatidic acid (LPA) acyltransferase reaction. Among other lysophospholipids tested, lysophosphatidylserine was most effective in enhancing PA biosynthesis. Since PA is an important intermediate for de novo biosynthesis of phospholipids, these results reveal a novel mechanism for promoting synthesis of PA enriched in polyunsaturated fatty acids in brain.
Loss of E-cadherin expression and outcome among patients with resectable pancreatic adenocarcinomas

Only a minority of patients who undergo surgical resection for pancreatic ductal adenocarcinoma are cured. Since patient outcome is not reliably predicted using pathological factors (tumor stage, differentiation, and resection margin status) alone, markers of tumor behavior are needed. One candidate predictor of pancreatic cancer outcome is E-cadherin status. CDH1 is a tumor suppressor gene encoding an important cell adhesion molecule (E-cadherin). The aim of this study was to determine if, among patients undergoing pancreaticoduodenectomy for pancreatic adenocarcinoma, loss of E-cadherin expression was an independent predictor of poor outcome. We examined patterns of loss of E-cadherin by immunohistochemistry in tissue microarrays of 329 surgically resected pancreatic ductal adenocarcinomas. E-cadherin expression was then correlated with outcome. Kaplan-Meier analysis and Cox proportional hazards regression modeling were used to assess the mortality risk. One hundred forty-one pancreatic adenocarcinomas (43%) had partial or complete loss of E-cadherin expression within the analyzed tissue cores. In most instances (134 cases, 41%), this loss was partial. Patients whose pancreatic adenocarcinomas had either complete loss (n=7; median survival, 5.5 months) or partial loss (n=134; 12.7 months) of E-cadherin expression had significantly worse median survival than those with uniformly intact E-cadherin expression (n=188; 18.5 months) by univariate (P=0.002) and multivariate (P=0.006) analyses. In subgroup analysis, patients with poorly differentiated cancers had a worse prognosis if their cancers had partial loss of E-cadherin expression (P=0.02). Among patients undergoing pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, partial loss of tumoral E-cadherin expression is an independent predictor of poor outcome.
When body temperature changes, does rectal temperature lag?

By using temporal artery and rectal thermometers, we followed temperatures in 45 febrile (>38.5°C) infants given an antipyretic drug. Sixty and 90 minutes after drug administration, temporal artery temperatures had decreased significantly more than rectal temperatures. When body arterial temperature changes rapidly, changes in rectal temperature may lag.
Injection of reagent ions into the selvedge region in fast-atom bombardment mass spectrometry.

A divided probe that incorporates a potassium aluminosilicate glass target and an analyte/glycerol matrix target, spatially separated, was used to inject potassium ions (K+) into the high-pressure “selvedge” region formed above the analyte/glycerol matrix target during fast-atom bombardment (FAB); [M+K]+ adduct ions that represent the types of gas-phase neutral molecules present in the selvedge region are observed. Computer modeling assisted in designing the divided target and an additional ion optical element for the FAB ion source to optimize interactions between K+ ions and the desorbed neutral molecules. The capability of injecting K+ ions into the FAB experiment has utility in both mechanistic studies and analyses. Experimental results here are consistent with a model for the desorption/ionization processes in FAB in which some types of neutral analyte molecules are desorbed intact and are subsequently protonated by glycerol chemical ionization. Unstable protonated molecules undergo unimolecular decomposition to yield observed fragment ions. The use of K+ cationization of analytes for molecular weight confirmation is demonstrated, as well as its utility in FAB experiments in which mixtures are encountered.
A Comparison of the Effects of Filtering and Sensorineural Hearing Loss on Patterns of Consonant Confusions.

It has been found that listeners with sensorineural hearing loss who show similar patterns of consonant confusions also tend to have similar audiometric profiles. The present study determined wheth...
Complex collective states in a one-dimensional two-atom system

We consider a pair of identical two-level atoms interacting with a scalar field in one dimension, separated by a distance ${x}_{21}$. We obtain collective decaying states, belonging to a complex spectral representation of the Hamiltonian. The imaginary parts of the eigenvalues give the decay rates, and the real parts give the average energy of the collective states. In one dimension there is strong interference between the fields emitted by the atoms, producing cooperative effects even when the atoms are far apart. The decay rates and the energy oscillate with the distance ${x}_{21}$. Depending on ${x}_{21}$, the decay rates will either decrease, vanish, or increase as compared with the one-atom decay rate. We have sub- and superradiance at periodic intervals. Our model may be used to study two-cavity electron waveguides. The vanishing of the collective decay rates then suggests the possibility of obtaining stable configurations, where an electron is trapped inside the two cavities.
Micro-cathode thruster for cube satellite propulsion

Summary form only given. Recently a new device namely micro-cathode arc thruster (μCAT) based on vacuum arc discharge has been developed for the spacecraft propulsion application1. The μCAT is a micro-Newton level thrust device that employs a magnetic field and is suited for the long-time operation of micro-thruster for the nano-satellite propulsion such as Cubesats2, 3.
Evaluating interest profiles based on users' judgment, interest change, and class specificity in the context of filtering medical documents

Quality of profiles is critical for the performance of information filtering systems. A series of experiments were conducted to investigate factors that can impact the profile acquisition process. Profiles in MedSIFTER, the system used in the study, are represented as degrees of interests over a set of fixed classes and for this research were based on established MeSH categories. We collected data from 12 subjects, who used the system in a mode where profile acquisition is exclusively based on feedback provision. User-provided profiles, machine-built profiles, transaction log records and written statements of subjects were the main empirical data. Profile similarities and consistency of feedback with explicit preferences for classes were measured. Results suggested that the system captured user preferences better when these preferences involved specific classes and when the user preferences didn't change significantly. Feedback assessments were more conducive to the representation of user preferences when these preferences involved specific classes. Discrepancies between what the subjects stated, when explicitly expressing their preferences, and what they actually did, when providing feedback, pointed to key factors related to the representation and modeling of the documents and profiles.
Time-varying forward bias and the expected excess return

Abstract This study, motivated by the parameter instability in the forward premium regression, proposes and estimates a time-varying forward bias model of three exchange rates, the dollar–DM, dollar–yen and dollar–pound rates, using the Kalman filter technique. A measure of the expected excess return is constructed. The properties of forward bias and the expected excess returns are investigated. We also examine the possible determinants of the time-varying forward bias and the expected excess return by testing four variants of the Lucas [J. Monetary Econ. 10 (1982) 335] model.
Hyaluronan metabolism: a major paradox in cancer biology

Paradoxically, both hyaluronan (HA) and hyaluronidases, the enzymes that eliminate HA, can correlate with cancer progression. Levels of HA on the surface of tumor cells are indicators of poor outcome. Certain hyaluronidases, products of tumor suppressor genes eliminated in the course of tumor spread, are used clinically in anti-cancer chemotherapy regimens. Such information would indicate that cancer progression is inhibited by hyaluronidase. Yet progression of certain cancers correlates with levels of hyaluronidase activity. An attempt is made here to understand such apparent contradictions by examining details of HA metabolism. Anabolic and catabolic pathways are comprised of the HA synthases and hyaluronidases, respectively. There are several enzymes that synthesize HA, each under a different control mechanism, generating products of differing polymer size. The hyaluronidases degrade HA in step-wise fashion, the polymer decreasing in size in quantum steps, each size-specific polymer having a different biological activity. Superimposed on these are the potent hyaluronidase inhibitors, about which very little is known. These components of HA metabolism are reviewed here for possible roles in supporting or suppressing malignant transformation, growth, invasion and metastatic spread of tumors. Such a systematic approach may reveal mechanisms used in the course of cancer progression, resolve some of the apparent disparities, render new prognostic markers, and provide new targets for therapeutic intervention.
Integrated Risk Framework for Gigawatt-Scale Deployments of Renewable Energy: The U.S. Wind Energy Case; October 2009

Assessing the potential environmental and human effects of deploying renewable energy on private and public lands, along our coasts, on the Outer Continental Shelf (OCS), and in the Great Lakes requires a new way of evaluating potential environmental and human impacts. The author argues that deployment of renewables requires a framework risk paradigm that underpins effective future siting decisions and public policies.
A role for the p53 pathway in the pathology of meningiomas with NF2 loss

The neurofibromatosis 2 locus (NF2) is inactivated through mutation and loss of heterozygosity (LOH) in 40–65% of all sporadic meningiomas, while the role of the p53 tumor suppression pathway in meningioma initiation and progression is still unclear. This study aims to determine if a p53 codon 72 arginine-to-proline polymorphism, found to be correlated with cancer development and cancer patient survival in other tumors, is associated with sporadic meningioma initiation or progression. We investigated Pro72 incidence in a cohort of 92 sporadic meningiomas and analyzed its association with histological grade (WHO classification) and with NF2 LOH (determined using polymorphic microsatellite markers on 22q). The Pro72 allele was not found to be selected for in the cohort. However, in the subgroup of meningiomas with NF2 LOH and carrying Pro72, 50.0% had high grade tumors (WHO grades II and III) compared to only 14.3% of those without NF2 LOH (OR = 6.0, CI = 1.56–23.11, P = 0.012). The significant association occurred only when considering subgroups of meningiomas with or without NF2 LOH, suggesting that not including NF2 status when analyzing study cohorts may explain the variability seen in the literature where all meningiomas were grouped together. Our data suggests a role for the p53 pathway in the progression of meningiomas in which NF2 is inactivated, and highlights the importance of accounting for NF2 LOH in future studies of meningiomas and the p53 pathway.
An Experimental Approach to the Effects of Predictability on Community Structure

This paper considers the effects of different levels of resource predictability on niche widths, competition and diversity in a community of three hummingbird species. Three pairs of hypotheses are tested: whether decreasing predictability (a) increases or decreases niche width, (b) increases or decreases competition and (c) increases or decreases diversity. The results show that complementary increases and decreases in niche width occur with decreasing predictability, while competition and diversity decrease, at least with extreme unpredictability. A model, which assumes the species to have similar resource preferences, and its predictions are examined. The dominant species, Lampornis clemenciae , excludes a subordinate species, Archilochus alexandri , from preferred resources. This defense becomes unprofitable with decreasing predictability and Archilochus invades the resources once vigorously defended by Lampornis . When the spectrum of resources is altered in the direction of decreasing suitability for both species, Lampornis becomes even more specialized and sensitive to the effects of unpredictability. A third species, Eugenes fulgens, steals resources undefended by Lampornis . These characteristics seem to be common to a number of communities in very different taxonomic groups, and characteristic of communities in which species share a common preferred resource. The question of how a community organized with distinct resource preferences responds to decreasing predictability remains open.
The role of phosphate in the action of thymidine phosphorylase inhibitors: Implications for the catalytic mechanism.

Abstract The design and synthesis of 5-fluoro-6-[(2-aminoimidazol-1-yl)methyl]uracil (AIFU), a potent inhibitor of thymidine phosphorylase (TP) with Ki-values of 11 nM (ecTP) and 17 nM (hTP), are described. Kinetic studies established that the type of inhibition of TP by AIFU is uncompetitive with respect to inorganic phosphate (or arsenate). The results obtained suggest that AIFU and other zwitterionic thymine analog inhibitors of TP act as transition state analogs, mimicking the anionic thymine leaving group, consistent with an SN2-type catalytic mechanism, and anchored by their protonated side chains to the enzyme-bound phosphate by electrostatic and H-bonding interactions.
Regulation of BAX and BCL-2 expression in breast cancer cells by chemotherapy.

Optimizing chemotherapeutic drug delivery strategies relies, in part, on identification of the most clinically effective sequence, dose, and duration of drug exposure. The combination of dose intensive etoposide (VP‐16) followed by cyclophosphamide has clinical efficacy in the treatment of advanced breast cancer. However, molecular mechanisms that underlie the effectiveness of this combination of chemotherapeutic agents have not been investigated. In this study we investigated regulation of BAX and BCL‐2 expression by VP‐16 and cyclophosphamide as a potential mechanism for the induction of breast cancer cell death induced by this regimen.
An optimization approach to tendon force analysis.

Abstract The problem of distribution of forces among synergistic muscles at a joint is examined. In order to arrive at a unique solution for the redundant system it is assumed that the solution represents an optimal response in terms of total muscle effort. The minimum muscle effort can be related to the concent of reciprocal inhibition. The nature of the resulting mathematical formulation is illustrated by a simple two tendon model. The formulation for a general multiaxial joint is then given, along with a general principle concerning the nature of resulting solutions. Results for two examples based upon a simplified biaxial model of the wrist are presented. Finally, the nature of several implicit assumptions in the analysis are reviewed and their consequences discussed.
Effect of Poly-Si on Electromigration Behaviors and Microstructure Characteristics of Au Metallization

For BJT and MOSFET, poly-Si is the most critical layer used as an emitter to improve the current gain in BJT and as a gate to improve the gate oxide reliability in MOSFET. In both cases, the poly-Si is then connected to the conductor. It is very important to understand how poly-Si affects the microstructure and the electromigration behavior of conductor. NIST test structures (length = 800μ, thickness = 0.7μ, widths = 1, 5, 10 μ) with Au conductor and TiW/TiWN/TiW barrier were used to study the impact of poly-Si. Two groups of samples were used: one with poly-Si under the barrier and the other without poly-Si. Thermal oxide was used to isolate the substrate from the conductor and Si3N4, was used as passivation. DC stress was performed at 175, 200, and 225°C. Microbeam X-ray Diffraction (μ XRD) was used to characterize the microstructure of the TiW barrier and Au metallization layers as a function of line length and width. The data indicates that samples with poly-Si have lower electromigration resistance for Au conductors for all widths and temperatures, with higher initial deformation fault densities on poly-Si.
Snail and Slug Promote Epithelial-Mesenchymal Transition through β-Catenin–T-Cell Factor-4-dependent Expression of Transforming Growth Factor-β3

Members of the Snail family of transcription factors have been shown to induce epithelial-mesenchymal transition (EMT), a fundamental mechanism of embryogenesis and progressive disease. Here, we show that Snail and Slug promote formation of beta-catenin-T-cell factor (TCF)-4 transcription complexes that bind to the promoter of the TGF-beta3 gene to increase its transcription. Subsequent transforming growth factor (TGF)-beta3 signaling increases LEF-1 gene expression causing formation of beta-catenin-lymphoid enhancer factor (LEF)-1 complexes that initiate EMT. TGF-beta1 or TGF-beta2 stimulates this signaling mechanism by up-regulating synthesis of Snail and Slug. TGF-beta1- and TGF-beta2-induced EMT were found to be TGF-beta3 dependent, establishing essential roles for multiple TGF-beta isoforms. Finally, we determined that beta-catenin-LEF-1 complexes can promote EMT without upstream signaling pathways. These findings provide evidence for a unified signaling mechanism driven by convergence of multiple TGF-beta and TCF signaling molecules that confers loss of cell-cell adhesion and acquisition of the mesenchymal phenotype.
Preoperative Decolonization Effective at Reducing Staphylococcal Colonization in Total Joint Arthroplasty Patients

Staphylococcus decolonization prior to surgery is used to prevent surgical site infections (SSIs) after total joint arthroplasty (TJA). To determine if current treatment protocols result in successful decolonization of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA), 106 consecutive patients were screened for nasal MSSA/MRSA colonization pre-operatively and on the day of surgery. Colonized patients used intranasal mupirocin twice a day and chlorhexidine showers daily 5 days prior to surgery. Pre-operatively, 24 joints (22.0%) were positive for MSSA colonization and 5 joints (4.6%) were positive for MRSA colonization. On the day of surgery, 3 joints (2.8%) who underwent decolonization were positive for MSSA colonization and 0 joints were positive for MRSA colonization. The reduction in MSSA colonization was significant (P<0.001), while the eradication of MRSA colonization approached statistical significance (P=0.063). Current decolonization protocols using intranasal mupirocin and chlorhexidine washes are effective for reducing MRSA/MSSA colonization.
Women's Representation in the Romanian Chamber of Deputies, 1992-2005: The Effect of District Economic Development

Although representational inequality continues to attract researchers' attention, few studies embark on substantive discussions with regard to variations in women's parliamentary representation across electoral districts. In postcommunist countries, such studies are even more scarce, and Romania in par- ticular has not been considered in this context. This article provides an empirical examination of: (1) the extent of inequality across districts with respect to the number of women in the Romanian Chamber of Deputies; (2) the relative stability of this inequality across multiple legislative periods; and (3) the contributions of economic development variables as determinants of representational inequality. Using a combination of data sources with electoral districts as the units of analy- ses reveals that although women's overall representation increased, inequality between districts is significant and remains stable across time. Furthermore, once a measure for women's parliamentary representation is standardized for district magnitude, level of economic development is a robust predictor of it, such that the greater the level of economic development, the greater the level of women's repre- sentation. Theoretical considerations conclude the article.
Peer support: healthcare professionals supporting each other after adverse medical events

The patient safety movement in healthcare is beginning to openly acknowledge the need to support the human side of adverse medical events in conjunction with evidence-based improvement initiatives. While medical literature has sporadically reported on the emotional impact of adverse events on healthcare professionals, little has been documented on the implementation of support services following these events. This article describes an adverse medical event where open communication and apology catalysed the development and implementation of a structured peer support service for care providers at the Brigham and Women's Hospital following adverse events. The Peer Support Service bypasses the stigmas that limit the utilisation of formal support services and offers care providers a safe environment to share the emotional impact of adverse events while serving as a foundation for open communication and a renewal of compassion in the workplace. As the breadth of stressors impacting healthcare professionals is revealed, the Peer Support Service is being recognised as a vital hospital-wide service. It also appears to offer an important leap forward in the critical areas of patient safety and quality of care.
Spatial and temporal patterns of predation on seeds of the surfgrass Phyllospadix torreyi

Spatial and temporal patterns of predation on seeds of the seagrass Phyllospadix torreyi S. Watson were quantified at four sites near Santa Barbara, California, USA. Over a period of four flowering seasons during 1995 to 1998, monthly patterns of seed fall and intensity of seed predation were similar among sites, but were temporally quite variable. Abundance of dispersed seeds varied greatly both among seasons and years. Within any one year, seeds were present in the environment every month, but they peaked in abundance during the fall months following the annual flowering period. Seeds were more abundant during the earlier years of the study. The intensity of predation steadily increased throughout the study period, from a low of ≤10% seeds consumed during 1995 to ∼50% consumption by 1997, and it was not correlated with abundance of seeds in the environment. Pre-dispersal seed loss also was estimated in two flowering seasons by counting the numbers of seeds consumed prior to release from the plant, and was relatively low (<15%). No differences were detected among the four study sites in patterns of pre-dispersal loss. Field surveys were done at two sites to identify potential seed predators. Three of the most abundant species identified in these surveys were tested in the laboratory to determine size-specific patterns of feeding activity and to assess which early life stages of P. torreyi (fruits within spadices, dehisced fruits, seedlings) were most vulnerable to predation. All three of the early life stages were consumed. The crabs Pugettiaproducta (Randall) and Pachygrapsus crassipes Randall were much more voracious predators than the isopod Idotea resecata Stimpson.