cssi/SciSciGPT-SciSciNet huggingface dataset:
DNN-Based RFID Antenna Tags Localization

Radio frequency identification technology (RFID) is increasingly becoming an integral part of the Internet-of-Things (IoT). It offers different advantages including battery-free operation, small form-factor, and low cost. This makes the RFID an enticing technology for an indoor localization-based application and services. Geometry based localization approaches often achieve low accuracy due to errors introduced by a multipath propagation and interference in indoor environments. Many range-based algorithms assume that reader position is known in advance and there are carefully placed reference tags. In contrast, this paper presents a data driven localization methodology for direction-of-arrival (DOA) estimation using a deep neural network processing of signal captured with a reader antenna array. The proposed approach learns the complex mapping of the radio waves interactions in adverse metal environments based on received signal strength indicator (RSSI) values. The RSSI is captured while electrically steering a planar phased array through the area of interest. The proposed methodology is evaluated with multiple tags placed on metallic surfaces. Using readily available measurements, the proposed approach is able to achieve an average DOA error of 5.93 degrees.
Comparison of virtual field device to humphrey visual field sita-fast in normal subjects

Purpose : Humphrey Visual Field (HVF) testing presents challenges for patients with limited mobility. Virtual reality-based visual field testing could provide a practical and portable alternative for visual field testing. This study examines the agreement between Virtual Field (VF), a virtual reality-based visual field test, and HVF. Methods : HVF SITA-Fast and VF BOLT Threshold were performed on both eyes of 40 normal subjects (age 23-66), right eye tested first. The test strategies were randomized. Subjects wore surgical masks in accordance with COVID-19 protocol. Outcome measures included mean deviation (MD), test time and visual field index (VFI). Each patient completed a survey about their experience. Eight eyes were excluded due to unreliable results (FL >20%, FP> 15%). Results : There was not a statistical difference between the right and left eye data on a paired t-test. P-values for HVF were 0.0824, 0.7206, and 0.5663 for MD, VFI and time respectively. P-values for VF were 0.3743, 0.9821, and 0.9872 for MD, VFI and time respectively. The right and left eyes were pooled for analysis. Average MD values were-0.19 dB for HVF and-2.38 dB for VF. Average VFI values were 99.4% for HVF and 96.2% for VF. Average test times were 176.5 sec for HVF and 194.0 sec for VF. When comparing VF to HVF, VF had mean differences (SD) of-2.18 dB (3.36),-3.2% (7.1) and 17.6 sec (39.7) in MD, VFI and time respectively. 95% CIs [-2.98,-1.40], [-4.89,-1.53], and [8.25, 26.89] respectively. All parameters were level dependent on Bland-Altman analysis with greater bias as the results deviated from normal. The bias in MD (mean difference ±SD) was lower for the 29 eyes that did not require trial lenses (-1.0±2.5 dB) than for the 43 eyes that required trial lenses (-3.1± 4.1 dB). 95% CI [-1.90, -0.04], [-4.33, -1.80] respectively. The difference in bias between the two groups was statistically significant (p=0.0163). There was a statistically significant difference (p = 0.0011) between subjects who reported some level of fogging on VF (61.6%) compared to the subjects who reported some level of fogging on HVF (19.4%). Conclusions : VF results did not agree with HVF results. There was more bias between the two tests when a trial lens was required. More subjects experienced fogging of the trial lens on VF than HVF.
What the US can learn from the UK about the protection of privacy

In February 2009 the House of Lords Constitutional Committee in the United Kingdom published the report Surveillance: Citizens and the State. Some have hailed this as a landmark document. The following is one of four commentaries that the editors of Surveillance & Society solicited in response to the report.
DEFLECTIONS OF GREAT LAKES ORE CARRIER HULL STRUCTURE BY FINITE ELEMENT ANALYSIS

Calculation of hull deflection with regard to machinery spaces of two Great Lakes bulk carriers is presented. Methods of modelling and analysis by the finite element method is discussed and the results are compared with measured results.
TIMP-3 in Bruch's membrane: changes during aging and in age-related macular degeneration.

PURPOSE. To assess the distribution, content, and function of tissue inhibitor of metalloproteinases (TIMP)-3 during aging in normal eyes for comparison with the levels observed in eyes with age-related macular degeneration (AMD). METHODS. Donor tissues analyzed included 36 normal eyes (14-96 years old) and 15 AMD eyes (74 -98 years old). A tissue strip including the fovea was used for immunohistochemistry. Western blot analysis was performed on extracts of the retinal pigment epithelium (RPE)- choroid complex from the posterior part of each eye. Immunoreactivity of TIMP-3 bands in each western blot was densitometrically quantitated. The inhibitory function of TIMP-3 was evaluated with reverse zymography. RESULTS. TIMP-3 was present uniformly across Bruch's membrane in the normal samples. In samples from donors more than 50 years of age, immunostaining was intense. TIMP-3 content ranged from 92 to 1061 ng/cm 2 and increased with age (r = 0.66). In AMD eyes, TIMP-3 distribution in Bruch's membrane was abundant in areas of continuous soft drusen but absent in areas below RPE atrophy. TIMP-3 levels in AMD eyes were significantly higher than in age-matched normal eyes (577 versus 877 ng/cm 2 ; P = 0.009). Inhibitory activity correlated well with TIMP-3 content (r = 0.82) and was also significantly higher in AMD eyes than in age-matched normal eyes (P < 0.001). CONCLUSIONS. During normal aging, TIMP-3 content in Bruch's membrane of the macula shows a significant increase. TIMP-3 content in AMD eyes was elevated relative to that of age-matched normal eyes. Higher levels of TIMP-3 may contribute to the thickening of Bruch's membrane observed in AMD.
On Patterned Ground

Intricate patterns of stones and mud are often found to decorate the ground in alpine and polar landscapes. In his Perspective, [Mann][1] highlights the explanation for these patterns offered by [Kessler and Werner][2] on the basis of a self-organization model. Acting over centuries, simple physical mechanisms such as the upfreezing of stones can produce the observed patterns wherever the ground repeatedly freezes and thaws. [1]: http://www.sciencemag.org/cgi/content/full/299/5605/354 [2]: http://www.sciencemag.org/cgi/content/short/299/5605/380
Automated Determination of Uric Acid, with Use of a Uricase—Peroxidase System

An automated colorimetric procedure is described for the determination of serum and urine uric acid with improved specificity. Hydrogen peroxide, formed when uric acid is oxidized by uricase, oxidatively couples with 3-methyl-2-benzothiazolinone hydrazone and N,N-dimethylaniline, in the presence of peroxidase, to produce a stable, sensitive indamine dye. The method is reproducible, and the results correlate well with those obtained by a manual spectrophotometric uricase procedure. Also, the automated procedure is resistant to many added reducing substances that cause positive interferences in alkaline phosphotungstate methods.
Immunomodulatory effects of nitrosoureas on the phenotype and functions of T cells in the thymus and periphery

Abstract We have recently demonstrated that nitrosoureas such as 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) and chlorozotocin (CLZ) can cure almost 100% of mice bearing LSA tumor, syngeneic to C57BL/6 mice. In contrast, similar or higher doses of streptozotocin (STZ) completely failed to cure LSA-bearing mice. Further studies revealed that the efficacy of nitrosoureas may depend on their immunomodulating properties. In the current study, therefore, we investigated the effect of these nitrosoureas on the immune system of normal mice. Treatment of C57BL/6 mice with 5 intraperitoneal injections of 20 mg/kg body weight of BCNU or CLZ caused an increase in the percentage of CD4 − CD8 − T cells and a decrease in the percentage of CD4 + CD8 + T cells in the thymus. In addition, such treatment also caused an increase in the percentage of CD4 + T cells without significantly affecting the CD8 + T cells in the thymus. However, when total cellularity of the thymus was studied, BCNU and CLZ were found to decrease the total number of CD4 + CD8 + T cells without significantly affecting the other subsets. In contrast, similar or higher (100 mg/kg body weight) doses of STZ had no significant effect on the total number and percentages of T cell subsets in the thymus. Also BCNU and CLZ but not STZ treatment caused a 50% decrease in the total number of CD4 + and CD8 + T cells in the spleen. When T cells in the spleens of nitrosourea-treated mice were functionally analysed, it was observed that BCNU and CLZ caused a dramatic decrease in the T cell responsiveness to Con A, anti-CD3 and phorbol myristate acetate plus calcium ionophore stimulation. In contrast, STZ treatment failed to significantly inhibit the T cell responsiveness to these activation signals. Using the accessory cell-dependent and -independent assays, BCNU and CLZ were found to suppress the functions of both T cells and macrophages. Also, addition of growth factors such as IL-1, IL-2, IL-4 and IL-6 failed to reconstitute the defective responsiveness of BCNU- and CLZ-treated T cells and macrophages. Together our data suggest that nitrosoureas have varying immunomodulating properties and this may in turn determine their efficacy in the treatment of cancer.
Three-dimensional finite element analysis of the mechanical behavior of spot welds

The mechanical behavior of spot welds under tensile-shear and symmetric coach-peel loading conditions is investigated in detail. The focus of the analysis is to reveal inherent three-dimensional features of the stress field in spot welds and to understand their effect on the structural performance and static failure modes of the spot welds. The findings of this investigation are obtained from detailed finite element solutions of spot welds for various ratio values between the sheet metal thickness and spot-weld diameter. These findings are then used to provide a mechanics-based rationale for relevant experimental observations in the literature. This study is carried out using the finite element method.
Experimental studies of the numerical stability of the gravitationaln-body problem

The gravitationaln-body problem is remarkably unstable numerically, in spite of the fact that near constancy of the energy and angular momentum makes it appear that the calculation should be reliable. In an attempt to understand why this should' be so, the properties of numerical solutions were explored through a perturbation technique in which equations of motion for the differences between two systems are integrated numerically. Results of a series of experiments show that the differences between computed systems and exact solutions to the differential equations tend to lie near the hypersurface on which the first integrals are conserved and preferentially along the trajectory through the @L-space. The numerical instability remains even when conservation, of the first integrals is improved by several orders of magnitude through a partial iterative refinement method. Implications of these results concerning the utility of computations of the gravitationaln-body problem are discussed. It may be possible to treat numerical effects as a kind of relaxation process, in which the relaxation time is identified with the characteristice-folding time of error growth. h.
Transfer across Perfused Human Placenta. III. Effect of Chain Length on Transfer of Free Fatty Acids

Extract: Human placentas were perfused in vitro with straight chain, even-numbered free fatty acids (FFA) and the transfer rates from maternal to fetal circulation were measured. The transfer rates increased logarithmically as chain length decreased. The clearances, calculated as percentage of clearance of antipyrine were: palmitic acid, 4%; myristic acid, 10%; lauric acid, 16%; decanoic acid, 18%; octanoic acid, 50%; hexanoic acid, 64%. Speculation: Transfer of hydrophobic materials through the placenta is a complex process which is probably affected by many factors. The present studies with FFA suggest that, for these compounds, protein binding may be particularly significant. If so, it may affect transfer rate by influencing release from maternal serum albumin, diffusion through the placenta, and uptake by fetal plasma. These several factors require further analysis.
Crystallization of microlites during magma ascent: the fluid mechanics of 1980–1986 eruptions at Mount St Helens

Eruptions of Mount St Helens (Washington, USA) decreased in intensity and explosivity after the main May 18, 1980 eruption. As the post-May 18 eruptions progressed, albitic plagioclase microlites began to appear in the matrix glass, although the bulk composition of erupted products, the phenocryst compositions and magmatic temperatures remained fairly constant. Equilibrium experiments on a Mount St Helens white pumice show that at 160 MPa water pressure and 900°C, conditions deduced for the 8 km deep magma storage zone, the stable plagioclase is An47. The microlites in the natural samples, which are more albitic, had to grow at lower water pressures during ascent. Isothermal decompression experiments reported here demonstrate that a decrease in water pressure from 160 to 2 MPa over four to eight days is capable of producing the albitic groundmass plagioclase and evolved melt compositions observed in post-May 18 1980 dacites. Because groundmass crystallization occurs over a period of days during and after decreases in pressure, microlite crystallization in the Mount St Helens dacites must have occurred during the ascent of each magma batch from a deep reservoir rather than continuously in a shallow holding chamber. This is consistent with data on the kinetics of amphibole breakdown, which require that a significant portion of magma vented in each eruption ascended from a depth of at least 6.5 km (∼160 MPa water pressure) in a matter of days. The size and shape of the microlite population have not been studied because of the small size of the experimental samples; it is possible that the texture continues to mature long after chemical equilibrium is approached. As the temperature, composition, crystal content and water content of magma in the deep reservoir remained approximately constant from May 1980 to at least March 1982, the spectacular decrease in eruption intensity during this period cannot be attributed to changes in viscosity or density of the magma. Simple fluld mechanical considerations indicate, however, that the observed changes in mass flux of magma can be modelled by a five-fold decrease in conduit radius from 35 to 7 m, produced perhaps by plating of magma along the conduit walls. The decreased ascent rates which accompanied the decrease in conduit radius can explain the change from closed-system to open-system degassing and the shift from explosive to effusive eruptions during 1980.
Prognostic Indicators of Alcoholism Treatment Outcome

This literature review is a systematic attempt to isolate the personal characteristics of alcoholics generally associated with their prognosis. Forty-five studies which met certain standards for inclusion are summarized here. The description of each study and its corresponding list of characteristics of alcoholics investigated for prognostic value are reported in tables. The tables do not reveal stable predictors across the studies, though some personal characteristics are more generally of predictive value than are others. A number of reasons for the absence of predictor stability are discussed--among them the possibility that certain treatments may work best with certain alcoholic patients.
“Fracking” Controversy and Communication: Using National Survey Data to Understand Public Perceptions of Hydraulic Fracturing

The recent push to develop unconventional sources of oil and gas both in the U.S. and abroad via hydraulic fracturing (“fracking”) has generated a great deal of controversy. Effectively engaging stakeholders and setting appropriate policies requires insights into current public perceptions of this issue. Using a nationally representative U.S. sample (N¼1061), we examine public perceptions of hydraulic fracturing including: “top of mind” associations; familiarity with the issue; levels of support/ opposition; and predictors of such judgments. Similar to findings on other emerging technologies, our results suggest limited familiarity with the process and its potential impacts and considerable uncertainty about whether to support it. Multiple regression analysis (r 2 ¼ .49) finds that women, those holding egalitarian worldviews, those who read newspapers more than once a week, those more familiar with hydraulic fracturing, and those who associate the process with environmental impacts are more likely to oppose fracking. In contrast, people more likely to support fracking tend to be older, hold a bachelor's degree or higher, politically conservative, watch TV news more than once a week, and associate the process with positive economic or energy supply outcomes. Based on these findings, we discuss recommendations for future research, risk communication, and energy policy.
Transport properties of alkali metal-graphite intercalation compounds

Abstract Basal resistivity ϱa has been measured in situ on MC8 compounds (M=K, Rb, Cs) from 5–300K. We find ϱa(T) = A+BT+CT2, in agreement with Suematsu et. al., except our value of A is ∼200 times smaller implying fewer defects. In MC8 compounds RH at 5K is positive and increases linearly with magnetic field, suggesting a complex Fermi surface. On the other hand, RH for RbC24 is negative and field-independent but the magnitude is inconsistent with a simple one-carrier model (assuming one free electron per Rb).
An automatic sample changer

Abstract The instrument described permits automatic assay of any number up to 40 radioactive samples. It may be programmed to record the number of the sample being assayed, the accumulated radiation count, and the elapsed time. Complete design data and circuit diagrams are included.
Tests with Mapharsen and Metachloridine in the Treatment of Blackhead in Turkeys

Abstract A natural outbreak of blackhead in the turkey flock at the Agricultural Research Center, Beltsville, Maryland, during the summer of 1946, presented an opportunity to test the efficacy of two drugs for the treatment of this disease. One hundred and fifty-eight Beltsville Small White, and 42 Broad-Breasted Bronze turkeys, ranging in age from 11 to 16 weeks, were used in these tests. All the birds presented clinical evidence of the disease at the time of treatment, but no birds which appeared moribund were included in the tests. Shortly before treatment the birds were placed in wire and slat-floored pens; prior to this they had been on range. Diagnosis of the disease as blackhead was based on the clinical symptoms and postmortem findings. All the birds in these tests which are listed as dying from blackhead, as well as other birds from the original flock which were not included in these . . .
Mineralogy of mine waste at the Vermont Asbestos Group mine, Belvidere Mountain, Vermont

Samples from the surfaces of waste piles at the Vermont Asbestos Group mine in northern Vermont were studied to determine their mineralogy, particularly the presence and morphology of amphiboles. Analyses included powder X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and Raman spectroscopy. Minerals identified by XRD were serpentine-group minerals, magnetite, chlorite, quartz, olivine, pyroxene, and brucite; locally, mica and carbonates were also present. Raman spectroscopy distinguished antigorite and chrysotile, which could not be differentiated using XRD. Long-count, short-range XRD scans of the (110) amphibole peak showed trace amounts of amphibole in most samples. Examination of amphiboles in tailings by optical microscopy, SEM, and EPMA revealed non-fibrous amphiboles compositionally classified as edenite, magnesiohornblende, magnesiokatophorite, and pargasite. No fibrous amphibole was found in the tailings, although fibrous tremolite was identified in a sample of host rock. Knowledge of the mineralogy at the site may lead to better understanding of potential implications for human health and aid in designing a remediation plan.
Interplay of spin gap and nanoscopic quantum fluctuations in intermetallic CeCu2Ge2

Abstract Neutron scattering measurements are used to elucidate interplay of the field-induced spin gap and the quantum fluctuations in archetypal heavy electron system CeCu 2 Ge 2 . A spin gap of Δ = 0.56 meV is found to develop near the field-induced quantum critical state at H c ≃ 8 T -driven by fluctuations of the long range antiferromagnetic order parameter. The superconducting transition temperature in many magnetic superconductors is found to exhibit one-to-one correspondence with the spin gap. In this regard, the demonstration of an interplay of the spin gap with the nanoscopic dynamic correlation provides new arena to explore direct relation between the quantum critical behavior and the unconventional superconductivity, especially in heavy electrons systems.
Gastrointestinal surgical patients' outcomes influenced by nutrition.

ABSTRACT Nutritional support differs for patients electing to have gastrointestinal surgical procedures and patients with abdominal trauma injuries. Trauma patients can rehabilitate more quickly than patients undergoing gastrointestinal surgeries, despite the traumatic injuries that require surgical intervention. This literature review examines and evaluates the clinical practice and management of these patients and the consequences of surgical nutritional deprivation. AORN J 71 (Jan 2000) 199–204.
Expression of chimeric genes in Caenorhabditis elegans.

Abstract We have shown the expression of transformed genes in the nematode Caenorhabditis elegans using a new gene fusion system. Vectors consisting of the flanking regions of a collagen gene (col-1) or a major sperm protein gene of C. elegans fused to the Escherichia coli uid A gene, encoding β-glucuronidase, were microinjected into worms and found to be propagated as high-copy extrachromosomal tandem arrays. We have detected β-glucuronidase activity in transformed lines, and have shown that the activity is dependent upon the correct reading frame of the construction and on the presence of the worm sequences. The enzyme activity was shown to be encoded by the chimeric β-glucuronidase gene by co-segregation analysis and by inactivation with specific antisera. Expression is at a very low level, and seems to be constitutive. We have used histochemical techniques to visualize the enzyme activity in embryos.
SPECIES, ROTATION, AND LIFE‐FORM DIVERSITY EFFECTS ON SOIL CARBON IN EXPERIMENTAL TROPICAL ECOSYSTEMS

Extensive areas of species-rich forests in the tropics have been replaced by tree monocultures over the last two decades, and the impact on biogeochemical cycles is unclear. We characterized effects on soil carbon dynamics of species identity and rotation frequency in experimental plantations containing three native, non-N-fixing tree species, Hyeronima alchoreoides, Cedrela odorata, and Cordia alliodora, grown in monocultures and in polycultures with two monocot species, Euterpe oleracea and Heliconia imbricata. Over all treatments, change in total soil organic carbon (TSOC, 0–15 cm) after 10 years ranged from a loss of 24% (0.9 mg/ha in 1-yr rotation of Cedrela) to an increase of 14% (0.6 mg/ha under Hyeronima polycultures). Species differed in their effects on quantities of TSOC (P = 0.038), but differences were more pronounced in light particulate organic matter (LPOM; P = 0.001), a biologically active, sand-size soil fraction that constituted 6% of TSOC. Effects of rotation frequency were strong; in ...
The political rhetoric of corporate globalisation and the possibilities for counter‐hegemonic Projects

From government officials through to industry leaders and labour organisers, and now at the community level, the debate about globalisation has had a profound effect on many people's welfare. Despi...
Tacit collusion among hospitals in price competitive markets.

Horizontal and vertical mergers, and coalition and network building activity have recently escalated in the US hospital industry in response to actual and threatened increases in competition. Parties to this industry's consolidation state that increased efficiency is the primary motive. However, increased consolidation may lead to increased awareness of inter-dependence, and facilitate ‘conscious parallelism’, or tacit collusion. In conjunction with this, selective contracting practices by payors with hospitals for negotiated prices may have increased the awareness of interdependence among price-competing hospitals. We posit that cost asymmetries arising from first-mover advantages to merged hospitals and multihospital chain members may be used strategically in local markets to facilitate tacit arrival at profit maximizing prices. Thus, hospital mergers and acquisitions which enhance efficiency in the short run may not yield net gains to society in the long run, as they may alter incentives which parameterize the potential for implicit cooperation. This outcome depends upon mitigating local market conditions, such as capacity utilization and market power held by payors. The current view that safeguarding emerging price competition is important necessitates careful analysis of how merger is likely to affect bargaining power between hospitals and purchasers. This complexity precludes the use of simple antitrust rules or guidelines in this industry.
Comments on: Why do i not accept plate tectonics?

Our emphasis has not been on citing detailed evidence that shows the weakness of Beloussov's position because we believe that such evidence is both ample and familiar. Rather we draw attention to what we see as his philosophical attitude and historical perspective. Beloussov's position, we conclude, derives from those of the German masters of contractional tectonics. Long before the advent of plate tectonics the inadequacies of this approach had been recognized and its place taken by hypotheses involving large-scale continental displacements in the writing of such tectonicians as Suess, Argand, and duToit.
Non-parametric estimation of automated weight-filling machinery for fresh citrus☆

Abstract Weight-sorting before packaging has the potential to reduce economic losses incurred by overfilling containers of fresh produce. However, due to the inherent variability in the individual weight of fresh produce items, the extent of savings and any potential drawback through excessive handling are difficult to assess. A nonparametric statistical procedure was developed to analyse automatic, fresh-produce bagging machinery operating to minimize overfill. The computational procedure was based on a random selection technique without article replacement for individual container filling. For conventional count-filling, percentage of underfilled containers was determined experimentally for two products, grapefruit and lemons, which have different numbers of articles per container. Simulations using this random selection approach were also conducted in order to analyse the performance of automatic filling between preselected minimum and maximum weight thresholds. The number of iterations in this mode of operation was analysed as an indication of possible product damage due to continued recycling. The mixing of sizes was found to reduce greatly search iterations. An algorithm for individual item selection, based on alternate selection above and below the mean weight, was found to reduce the projected number of search iterations.
Parasympathetic innervation maintains epithelial progenitor cells during salivary organogenesis

The maintenance of a progenitor cell population as a reservoir of undifferentiated cells is required for organ development and regeneration. However, the mechanisms by which epithelial progenitor cells are maintained during organogenesis are poorly understood. We report that removal of the parasympathetic ganglion in mouse explant organ culture decreased the number and morphogenesis of keratin 5-positive epithelial progenitor cells. These effects were rescued with an acetylcholine analog. We demonstrate that acetylcholine signaling, via the muscarinic M1 receptor and epidermal growth factor receptor, increased epithelial morphogenesis and proliferation of the keratin 5-positive progenitor cells. Parasympathetic innervation maintained the epithelial progenitor cell population in an undifferentiated state, which was required for organogenesis. This mechanism for epithelial progenitor cell maintenance may be targeted for organ repair or regeneration.
Envy and positional bias in the evolutionary psychology of management

We propose that humans have evolved at least two specialized cognitive adaptations shaped by selection to solve problems associated with resource competition: (1) a positional bias by which individuals judge success in domains that affect fitness in terms of standing relative to their reference group; and (2) envy, an emotion that functions to alert individuals to fitness-relevant advantages enjoyed by rivals and to motivate individuals to acquire those same advantages. We present new data supporting the existence of design features of these hypothesized psychological adaptations and discuss implications for economists, organizations, marketers, and managers. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of ground state disorder without frustration: Liquid crystals with interactions favoring orthogonal ordering

Abstract We investigate the effect of nonzero ground state disorder which does not involve any frustration or competition, by studying a nematic liquid crystal-type model with an interaction which favors orthogonal orientations of nearest-neighbor rods. From Monte Carlo simulations, we find a phase transition with long-range ordering for d = 3, so that the ground state disorder does not increase the minimum integral dimensionality where the model has a (finite-temperature, symmetry-breaking) phase transition. The nature of the long-range order is discussed. The transition is found to be continuous, in agreement with a theoretical argument. For comparison, the d = 4 and d = 2 versions of the model are also briefly studied.
Structural changes in single crystal copper-alpha brass diffusion couples☆

Abstract Structural changes associated with Kirkendall diffusion in single crystal copper-alpha-brass couples have been studied. Vapour—solid couples in which zinc was diffused into copper from the vapour were investigated using metallographic and X-ray techniques. The following effects were found under certain conditions in the diffusion zone: 1. (1) dislocation formation; 2. (2) arrangement of dislocations into subboundaries; 3. (3) recrystallization and formation of new grains; 4. (4) twin formation. The dislocation density and fineness of substructure were greatest at the lowest diffusion temperatures. Re-crystallization was found at low diffusion temperatures, and twin formation was always associated with recrystallization. An explanation of these phenomena is given in terms of the production and subsequent redistribution of dislocations by climb and slip mechanisms during diffusion.
Higher Derivative Gravity, Causality and Positivity of Energy in a UV complete QFT

Abstract In this note we discuss the relation between the constraints imposed by causality in the bulk of AdS and the condition of positivity of the energy measured in ideal calorimeters in a collider experiment in the dual CFT. We first extend the analysis in the literature and recover all bounds imposed by causality of the boundary theory in the bulk dynamics for all polarizations of the graviton and the gauge boson field. These results translate to specific bounds for the ratio of central charges a c in the dual CFT, already found by analyzing the energy one point function. Then, we generalize this discussion and we study shock wave backgrounds in which we make manifest the relation between causality in the bulk and the three point function in the dual field theory. We remark that particular care has to be given to the exponentiation procedure of the three point function when solving the classical equations of motion in the higher gravity theory, as it is not clear that every theory will present causality problems. Finally, we present a field theoretic argument explaining the positivity of energy condition in any UV complete QFT.
The Effect of Flow Rate on the In-Situ Gelation of a Chrome/Redox/Polyacrylamide System

Presentation of experimental data on the gelation of a polyacrylamide/thiourea/Cr(4) gel system in unconsolidated sandpacks at flow rates typical of those encountered beyond the immediate vicinity of a wellbore
A selective imidazobenzodiazepine antagonist of ethanol in the rat

Ethanol, at pharmacologically relevant concentrations of 20 to 100 mM, stimulates gamma-aminobutyric (GABA) receptor-mediated uptake of 36Cl-labeled chlorine into isolated brain vesicles. One drug that acts at GABA-benzodiazepine receptors, the imidazobenzodiazepine Ro15-4513, has been found to be a potent antagonist of ethanol-stimulated 36Cl- uptake into brain vesicles, but it fails to antagonize either pentobarbital- or muscimol-stimulated 36Cl- uptake. Pretreatment of rats with Ro15-4513 blocks the anticonflict activity of low doses of ethanol (but not pentobarbital) as well as the behavioral intoxication observed with higher doses of ethanol. The effects of Ro15-4513 in antagonizing ethanol-stimulated 36Cl- uptake and behavior are completely blocked by benzodiazepine receptor antagonists. However, other benzodiazepine receptor inverse agonists fail to antagonize the actions of ethanol in vitro or in vivo, suggesting a novel interaction of Ro15-4513 with the GABA receptor-coupled chloride ion channel complex. The identification of a selective benzodiazepine antagonist of ethanol-stimulated 36Cl- uptake in vitro that blocks the anxiolytic and intoxicating actions of ethanol suggests that many of the neuropharmacologic actions of ethanol may be mediated via central GABA receptors.
Ringing revivals in the interaction of a two-level atom with squeezed light

The Jaynes–Cummings interaction of a two-level atom with the radiation field is studied when the radiation is initially in a strongly squeezed coherent state. The dynamic response of the atomic inversion shows echoes after each revival when the squeezed coherent state exhibits an oscillatory photon-counting distribution due to the phase-space interference effect. The sensitivity of the dynamic behavior to approximations used in computing the atomic inversion is discussed. Comparison is made with the intensity-dependent interaction model of Buck and Sukumar [ Phys. Lett.81A, 132 ( 1981)]; this model does not exhibit echoes. The mean, variance, and entropy for the photon-number distribution are calculated and found to show behavior similar to that of the atomic inversion.
Do Sexual Risk Behaviors Differ Between Heterosexual Youth Infected With HIV Perinatally Versus Sexually

Abstract Purpose To determine if sexually active heterosexual HIV-infected 15– to 24–year-old youth have different sexual or other risk behaviors depending on whether they were infected perinatally or heterosexually. Methods We compared youth aged 15 to 24 years who acquired HIV perinatally or sexually and were interviewed in-person or by phone for partner services by the New York City Department of Health and Mental Hygiene. We included heterosexually active youth with at least one sexual partner of the opposite sex in the past 12 months, and excluded men who have sex with men and injection drug users. We used χ 2 tests and t tests to compare demographics, sexual risk behaviors, partner services outcomes, and viral loads. Results Both groups reported few partners (median 1, mean 2), and only 12% of partners of perinatally infected youth were previously diagnosed (18% of sexually infected youths' partners). A minority reported always using condoms. Both groups had similar rates of sexually transmitted infections and median HIV plasma RNA (perinatally infected: 5,140 copies/mL; sexually infected: 6,835 copies/mL). Despite these similarities, among tested partners not previously HIV diagnosed, none of 17 named by perinatally infected youth was newly HIV diagnosed, whereas 21% (8/39, p = .09) of those named by sexually infected youth were newly diagnosed. Conclusions Though perinatally infected youth did not transmit HIV infection to previously undiagnosed partners, they had similar HIV-related risk behaviors to youth infected sexually who reported on risks that led to their infection. HIV prevention among HIV-infected youth remains a critical challenge.
Potential foreign competition in US manufacturing

Abstract Trade barriers are falling and firms are competing in increasingly open international markets. The data reveal considerable heterogeneity across industries in the intertemporal path of import-shares. Against this backdrop, we focus on an issue that is increasingly important for competition policy analysis: ‘potential’ foreign competition. Inadequate attention to this aspect could result in a biased picture of total competition, leading to misguided antitrust decisions. Drawing on the conceptual framework outlined by Landes and Posner [Harvard Law Review, 94 (1981) 937], we measure potential foreign competition by the intertemporal response of industry import-share to industry-specific and aggregate economic factors, and our estimates indicate wide variation across industries in this dimension. A particularly striking finding is that highly concentrated industries, which are more likely to be subject to antitrust scrutiny, have a greater degree of potential foreign competition than industries with low concentration, even though the extent of actual foreign competition is similar across these groups of industries.
Osprey: peer-to-peer enabled content distribution

As the size of data and files increases, digital repositories face a growing problem in content distribution. High quality multimedia and research data sets can range from 100's of megabytes to over a terabyte. Web-based digital repositories may exper ience a substantial increase in operating and bandwidth costs when providing materials to the public. Peer-to-peer networks are sometimes suggested as an alternative to traditional centralized repositories [2]. However, critical issues such as data inte grity, access control, and content availability exist when using peer-to-peer technologies [1].Osprey (http://osprey.ibiblio.org) addresses these problems by combining a flexible metadata management system with the BitTorrent peer-to-peer protocol. A Web database application provides searching and browsing of collection objects, and the peer-to-peer component lowers the bandwidth costs by employing distributed downloading. The Permaseed application supplies reliable, persistent peer-to-peer access to files in the digital repository.
The Power of Assemblages and the Fragility of Things

In responding to these thoughtful essays by Mark Wenman, James Williams, Gulshan Khan, David Howarth, Saul Newman and David Owen on my work, I seek to place each into conversation with the others as well as with me.
Germ-soma differentiation in volvox.

Volvox carteri is a spherical green alga with a predominantly asexual mode of reproduction and a complete germ-soma division of labor. Its somatic cells are specialized for motility, incapable of dividing, and programmed to die when only a few days old, whereas its gonidia (asexual reproductive cells) are nonmotile, specialized for growth and reproduction, and potentially immortal. When a gonidium is less than 2 days old it divides to produce a juvenile spheroid containing all of the somatic cells and gonidia that will be present in an adult of the next generation. The first visible step in germ-soma differentiation is a set of asymmetric cleavage divisions in the embryo that set apart small somatic initials from their large gonidial-initial sister cells. Three types of genes have been found to play key roles in germ-soma specification. First a set of gls genes act in the embryos to shift cell-division planes, resulting in the asymmetric divisions that set apart the large-small sister-cell pairs. Then a set of lag genes act in the large cells to prevent somatic differentiation, while the regA gene acts in the small cells to prevent reproductive development. An inducible transposon was used to tag and recover some of these and other developmentally important genes. The glsA gene encodes a chaperone-like protein that, like another chaperone that is one of its putative binding partners, is associated with the cell division apparatus, although how this leads to asymmetric division remains to be elucidated. The regA gene encodes a somatic-cell-specific nuclear protein that appears to function by repressing genes required for chloroplast biogenesis, thereby preventing somatic cells from growing enough to reproduce. Somatic-cell-specific expression of regA is controlled by three intronic enhancers.
Serologic Testing for Aspergillosis in Commercial Broiler Chickens and Turkeys

Sera samples from commercial broiler chickens and turkeys diagnosed with respiratory and disseminated aspergillosis were tested for the presence of antigen and antibody to Aspergillus. Antigen detection consisted of testing for two cell-wall components, beta-glucan and galactomannan, which have been used extensively in human medicine. There were significantly higher levels of galactomannan in all broiler chicken submissions (100%) and antibody to Aspergillus in 6 out of 9 submissions (66.6%) vs. control birds. Beta-glucan analyses did not show any differences among levels in the broiler chicken groups. There were significantly higher levels of galactomannan antigen in 4 out of 7 submissions (57.1%) of aspergillosis in commercial turkeys, while only 2 out of 7 submissions (28.5%) had higher levels of antibody to Aspergillus vs. the control group. This study shows that diagnosis of respiratory and disseminated aspergillosis may be performed by detection of galactomannan antigenemia and antibodies in broiler chickens and to an extent in turkeys.
LC Material Studies for Atmospheric Compensation Using a Liquid Crystal Light Valve

Abstract Atmospheric compensation has been demonstrated using a liquid crystal light valve as a monolithic, integrated, wavefront sensor-corrector in a closed loop, all-optical configuration. For successful demonstration of this device, liquid crystal candidates were surveyed for high birefringence and fast time response in the blue region. BDH-E44 was selected with the highest figure of merit and a birefringence of 0.342 at 410 nm. Accelerated photostability studies indicated that the exclusion of oxygen/moisture extended the LC lifetime by twofold, while photo-exposure and applied electrical signal limited the lifetime due to photoinduced electrochemical degradation. A sealed BDH-E44 test cell after 60 Wh/cm2 of 405 × 20 nm light and electrical exposure exhibited 3% decrease in the effective δn and a 12% shift in the operating voltage. However, the LC recovered from the sealed test cell after photo exposure showed no significant change in composition.
Conformational preferences of C1-oxygenated acyclic chiral alkenes: The effect of vinyl and allyl substituents

Abstract The conformational preferences of several chiral alkenes have been studied by the variable temperature NMR technique. Electron-withdrawing groups (EWG) enhance the C-O eclipsed form, and electron-releasing groups (ERG) favor the C-H eclipsed form in these C1-oxygenated chiral alkenes.
MEASURING FACTORY FOCUS: AN EMPIRICAL STUDY

Focus in the manufacturing plant is generally deemed to be an important element of success in manufacturing strategy. Yet, little work has been completed in the measurement of plant focus and a dearth of empirical evidence exists to support the broad popularity of this concept. This paper presents a plant focus measurement approach and reports the results of a field study that uses a site visit research design to apply the focus measure to a multi-industry sample of manufacturing plants. Regression analysis is used to study the relationships between the plant focus variable and the environmental variables of plant size, number of product lines, plant age, number of processes, and type of processes. Although highly intuitive, these relationships have undergone very little empirical study in the literature. Our study provides evidence of a strong logarithmic relationship between our plant focus measure and the number of product lines. Support is also demonstrated in that our measure of plant focus is linked to the number and type of manufacturing processes. However, the variables of plant age and plant size do not appear related to the plant focus measure. The literature-based multicriteria focus measure can be used by managers and researchers as an objective, formal, and generalizable approach for assessing plant focus, for identifying areas in the plant that detract from focus, and for tracking focus improvement efforts over time.
Particle Acceleration in Solar Flares

A review of observational data supports the proposal that there are two distinct phases of particle acceleration in solar flares. ‘Phase 1 ’ is associated with the flash phase and is here interpreted as acceleration during field-line reconnection. ‘Phase 2’ is associated with type II and type IV radio bursts, and is ascribed to stochastic acceleration in the turbulent plasma behind a magnetohydrodynamic shock formed ahead of an ejected plasmoid.
Early-Type Stars: Most Favorable Targets for Astrometrically Detectable Planets in the Habitable Zone

Early-type stars appear to be a difficult place to look for planets astrometrically. First, they are relatively heavy, and for fixed planetary mass the astrometric signal falls inversely as the stellar mass. Second, they are relatively rare (and so tend to be more distant), and for fixed orbital separation the astrometric signal falls inversely as the distance. Nevertheless, because early-type stars are relatively more luminous, their habitable zones are at larger semimajor axis. Since astrometric signal scales directly as orbital size, this gives early-type stars a strong advantage, which more than compensates for the other two factors. Using the Hipparcos Catalog, we show that F and A stars constitute the majority of viable targets for astrometric searches for planets with semimajor axes currently in the habitable zone. Thus, astrometric surveys are complementary to transit searches, which are primarily sensitive to habitable planets around late-type stars.