cssi/SciSciGPT-SciSciNet huggingface dataset:
Quality of service support in IEEE 802.11 wireless ad hoc networks

Abstract Supporting Quality of Service (QoS) in wireless networks is a challenging problem. The IEEE 802.11 LAN standard was developed primarily for elastic data applications. In order to support the transmission of real-time data, a polling-based scheme called the point coordination function (PCF) was introduced in IEEE 802.11. However, PCF was not able to meet the desired and practical service differentiation requirements to fulfill the need of real-time data. Therefore, Task Group E of the IEEE 802.11 working group released several IEEE 802.11e drafts, whose main task is to support QoS in IEEE 802.11 LANs. The polling scheme of PCF is extended in IEEE 802.11e into the more complex hybrid coordination function (HCF). We found that HCF has several performance issues that may affect its anticipated performance. In this paper, we address these issues and propose a QoS enhancement over PCF, called enhanced PCF (EPCF) that enables Wireless LAN to send a combination of voice, data and isochronous data packets using the current IEEE 802.11 PCF. First, we compare the performance of the proposed model (EPCF) with the HCF function of the IEEE 802.11e through simulation. Second, we extend the proposed model (EPCF) to work in a multihop wireless ad hoc mode and present the advantages and limitations in this case. Simulation results demonstrate an enhanced performance of our scheme over the legacy PCF and a comparable performance to the IEEE 802.11e HCF in terms of the average delay and system throughput. However, EPCF is much simpler than HCF, provides flow differentiation, and is easy to implement in the current IEEE 802.11 standard.
Brief Lags in Interrupted Sequential Performance

We examined effects of adding brief (1 second) lags between trials in a task designed to study errors in interrupted sequential performance. These randomly occurring lags could act as short breaks and improve performance or as short interruptions and impair performance. The lags improved placekeeping accuracy, and to interpret this effect we developed a cognitive model of placekeeping operations, which accounts for the effect in terms of the lag making memory for recent performance more distinct. Self-report data suggest that rehearsal was the dominant strategy for maintaining placekeeping information during interruptions, and we incorporate a rehearsal mechanism in the model. To evaluate the model we developed a simple new goodness-of-fit test based on analysis of variance that offers an inferential basis for rejecting models that do not accommodate effects of experimental manipulations. Brief, unfilled lags between trials improve placekeeping accuracy on the post-lag trialA model of the effect attributes it to sharpened memory for recent performance, with implications for interpreting speed-accuracy tradeoffs more generallyA model evaluation technique is developed that tests goodness of fit inferentially and helps identify incorrect theoretical assumptions
Delta excitations in heavy nuclei induced by (3He,t) and (p,n) reactions.

Delta excitations in heavy nuclei, induced by charge exchange reactions, are studied using the surface response model. The residual pion-exchange interaction and the self-energy of the delta in a nuclear medium is included in the random-phase-approximation response. The peak position observed in ${(}^{3}$He,t) reactions can be explained by the self-energy of the delta extracted from pion-nucleus scattering, and the magnitude of the cross section is consistent with Glauber theory. The comparison to (p,n) data is reasonable; contributions from neutron decay of the delta, which are left out in the calculations, constitute a substantial experimental background.
High yield production of formate by hydrogenating CO2 derived ammonium carbamate/carbonate at room temperature

A sustainable economy is needed to recycle carbon rather than to irreversibly use stored carbon in fossil fuels. Instead of releasing CO2 into the atmosphere, its value can be recognized as a base C1 material for chemicals. In this study, a new CO2 utilization strategy is developed via the hydrogenation of CO2 derived ammonium carbamates/carbonates, which are the intermediates in industrial urea production or carbon capture processes, to produce value-added formate chemicals. A high yield of formate, ∼92%, was achieved after hydrogenating ammonium carbamates in the ethanol–water solution at room temperature with the carbon supported palladium nano-catalyst. The ethyl carbonate ions in the ammonium carbamate/carbonate solutions were speciated by 13C NMR and were attributed to the superior hydrogenation efficiency. Ammonium ions promote the formation of ethyl carbonate ions in the presence of ethanol. The solvent affects the distribution of the reactive intermediates.
Investigation of the binary model of scattering of 1 keV to 25 eV Ar+ ions from a Cu surface ∗☆

Abstract The validity of the binary collision approximation for describing the scattering of low energy Ar ions from a polycrystalline Cu surface was investigated. The Ar ions were incident upon the target surface at an angle of 45° (with respect of the plane of the surface). The range of primary ion energy studied was 1000–25 eV. An ultra-high vacuum magnetic sector mass spectrometer was used to analyze those secondary ions emitted from the specimen surface at an angle of 90° with respect to the primary ion beam. The scattered ions were identified and their energies measured. No significant deviation from the prediction of the binary collision model was found throughout the range of energy studied.
Conditional Probability and Defeasible Inference

We offer a probabilistic model of rational consequence relations (Lehmann and Magidor, 1990) by appealing to the extension of the classical Ramsey–Adams test proposed by Vann McGee in (McGee, 1994). Previous and influential models of non-monotonic consequence relations have been produced in terms of the dynamics of expectations (Gardenfors and Makinson, 1994; Gardenfors, 1993).‘Expectation’ is a term of art in these models, which should not be confused with the notion of expected utility. The expectations of an agent are some form of belief weaker than absolute certainty. Our model offers a modified and extended version of an account of qualitative belief in terms of conditional probability, first presented in (van Fraassen, 1995). We use this model to relate probabilistic and qualitative models of non-monotonic relations in terms of expectations. In doing so we propose a probabilistic model of the notion of expectation. We provide characterization results both for logically finite languages and for logically infinite, but countable, languages. The latter case shows the relevance of the axiom of countable additivity for our probability functions. We show that a rational logic defined over a logically infinite language can only be fully characterized in terms of finitely additive conditional probability.
Building the security behavior observatory: an infrastructure for long-term monitoring of client machines

We present an architecture for the Security Behavior Observatory (SBO), a client-server infrastructure designed to collect a wide array of data on user and computer behavior from hundreds of participants over several years. The SBO infrastructure had to be carefully designed to fulfill several requirements. First, the SBO must scale with the desired length, breadth, and depth of data collection. Second, we must take extraordinary care to ensure the security of the collected data, which will inevitably include intimate participant behavioral data. Third, the SBO must serve our research interests, which will inevitably change as collected data is analyzed and interpreted. This short paper summarizes some of our design and implementation benefits and discusses a few hurdles and trade-offs to consider when designing such a data collection system.
Characterization of ion trapping motion in the dual cell ion cyclotron resonance spectrometer: experimental and theoretical studies

Abstract Ions produced in one cell of a dual cell Fourier transform-ion cyclotron resonance mass spectrometer are partitioned by temporarily grounding the conductance limit separating mass two cells. Theoretical predictions for transfer behavior were produced by used of Runge—Kutta integration and an elliptical function method to calculate ion motion during the transfer period. Comparison between the experimental and theoretical results indicates that ion transfer between cells is occurring on a more harmonic potential surface than expected. These results suggest that only ions formed near the center of the source cell can be effectively transferred and/or detected.
Performance Attributions and the Type a Behavior Pattern Causal Sources Versus Causal Dimensions

Past research has produced conflicting results concerning the manner in which Type As and Bs make attributions following success and failure. Some studies find that Type As are more likely than Type Bs to blame themselves for all outcomes, particularly failure. Other research indicates that Type As are more self-serving in their postperformance attributions. Research indicating more self-blame by Type As typically uses a causal source approach, that is, subjects are asked to indicate the extent to which common causal sources (e.g., ability, effort) produced the outcome. The causal-dimension approach, used in studies that find Type As to be more self-serving than Type Bs, assesses the dimensional structure of causes directly. One possible explanation for the divergence in results is that Type As and Bs differ in their interpretations of the dimensional structure underlying common causal sources, with Type As interpreting those causes in a more self-servingc manner. Results provided support for this hypothe...
Clinical management of impactedmaxillary canines

Ectopic eruption and impaction of canines is a frequently encountered clinical problem. The incidence of impaction ranges between 1% and 3%. The cause of canine impaction can be the result of localized factor(s) or can be a polygenic multifactorial inheritance and associated with other dental anomalies. There are a number of possible sequelae to canine impactions, ranging from loss of space in the arch to resorption of the roots of the neighboring teeth. Although the management of the ectopically erupting teeth necessitates the combined expertise of a number of clinicians, the orthodontist should have the primary responsibility of coordinating these efforts to provide the patient with the optimal treatment options with the most stable and favorable outcome.
The fate of a progressive science: the Harvard Fatigue Laboratory, athletes, the science of work and the politics of reform

In the early twentieth century, fatigue research marked a site of conflicting scientific, industrial, and cultural understandings of working bodies. Many fatigue researchers understood fatigue to be a physiological fact and allied themselves with Progressive-era reformers in urging industrial regulation. Reformers clashed with advocates of Taylorism, who held that productivity could be perpetually increased through managerial efficiency. Histories of this conflict typically cease with the end of the First World War. I examine the work of the Harvard Fatigue Laboratory in the 1920s and 1930s to explore the impact that the introduction of biochemical methods had on the relationship between science and reform. The Laboratory developed sophisticated techniques to study the blood of exercising individuals. In particular, it found that exercising individuals could attain a biochemically “steady state,” or equilibrium, and extrapolated from this to assert that fatigue was psychological, not physiological, in nature. In contrast to Progressive-era research, the Laboratory reached this conclusion through laboratory examination, not of workers, but of Laboratory staff members and champion marathon runners. I present the Laboratory's institutional history, scientific work, and finally how common cultural understandings of athletes and work lent plausibility to its efforts to make authoritative statements about industrial conditions.
Solid and liquid junctions

Abstract Atomic scale energetics, structure, and formation mechanisms of solid and liquid junctions occurring between a solid metal tip and a clean metal surface or between the tip and a liquid film of hexadecane molecules adsorbed on a solid surface, are investigated using large-scale molecular dynamics simulations. The solid intermetallic junctions exhibit crystalline structure and their elongation mechanism, upon slow retraction of the tip from the surface after contact, involves a sequence of plastic deformations and yield processes, coupled with structural rearrangements. The molecular liquid is layered in the capillary junction for small separations between the two confining solid surfaces. Further separation results in a transition to a liquid-like region in the middle of the elongated liquid column. Investigations of the molecular scale origins of capillary liquid junction formation, and of the Young-Laplace equation applied to nanoscale liquid junctions, as well as consequences of solid and liquid junction formation for force measurements via atomic force microscopy, are discussed.
Relationship Beliefs, Attributions, and Partner Behaviors Among Depressed Married Women.

Existing research documents that marital distress is strongly associated with depression; however, less is known about specific features of relationship functioning that are associated with depression. In the current study, we tested whether marital attributions, dysfunctional relationship beliefs, and partners’ reinforcing and aversive behavior were associated with major depression in married women. Compared to nondepressed wives, depressed wives reported stronger endorsement of several dysfunctional relationship beliefs, even when controlling for relationship distress. Depressed women also reported more dysfunctional relationship attributions and more negative partner behaviors; however, these results were not significant when marital distress was controlled. We also assessed relationship factors in husbands of depressed and nondepressed women. Husbands of depressed wives did not report significantly higher levels of dysfunctional attributions or beliefs. They did report more negative and fewer positive partner behaviors; however, husbands’ marital distress seemed to account for these findings. Results support an integration of cognitive, behavioral, and interpersonal models of depression.
Ascending sliding arch aortoplasty: a novel technique for repair of arch hypoplasia.

Background Coarctation of the aorta (CoA) is often associated with clinically significant hypoplasia of the aortic arch. Historically, patch aortoplasty or bypass procedures have been the preferred techniques when arch augmentation is required in children beyond infancy. While safe and effective, these approaches require prosthetic or biologic material without the potential for growth, or normal endothelial and physiologic elastic function. This retrospective study reviews the use of a novel technique, ascending sliding arch aortoplasty, that utilizes viable autologous tissue for repair of arch obstruction in children beyond infancy. Methods Between April 2002 and January 2007, 8 patients ranging in age from 18 months to 15 years underwent repair of CoA with arch hypoplasia using ascending sliding arch aortoplasty. All patients were approached through median sternotomy, utilizing cardiopulmonary bypass and selective antegrade cerebral perfusion. Results There was no mortality or major morbidity. One toddler had pneumonia, resulting in an increased length of stay. Median duration of hospitalization was 5.8 days, ranging from 3 to 10 days. No patient had evidence of residual obstruction or recurrent CoA at a mean follow-up interval of 36 months. Conclusions Ascending sliding arch aortoplasty for CoA with arch obstruction in children beyond infancy is a safe technique that can be accomplished without deep hypothermic circulatory arrest. There is no evidence of recurrence at midterm follow-up. Because the augmentation is accomplished with viable autologous aortic tissue, the potential for growth, preserved elasticity and endothelial function, and resistance to infection make this method attractive for use in the young.
Contaminant classification of poultry hyperspectral imagery using a spectral angle mapper algorithm

Since hyperspectral imaging technique has been demonstrated to be a potential tool for poultry safety inspection, particularly faecal contamination, a hyperspectral image classification method was developed for identifying the type and source of faecal contaminants. Spectral angle mapper (SAM) supervised classification method for hyperspectral poultry imagery was performed for classifying faecal and ingesta contaminants on the surface of broiler carcasses. Spatially averaged spectra of three different faeces from the duodenum, caecum, colons, and ingesta of maize/soya bean diet were used for classification data. The SAM classifier using reflectance of hyperspectral data with 512 narrow bands from 400 to 900 nm was able to classify three different faeces and ingesta on the surface of poultry carcasses. Based on the comparison with ground truth region of interest, both classification accuracy and kappa coefficient, which quantifies the agreement of classification, increased when spectral angle increased. The overall mean accuracy and corresponding mean kappa coefficient to classify faecal and ingesta contaminants were 90·13% (standard deviation of 5·40%) and 0·8841 (standard deviation of 0·0629) when a spectral angle of 0·3 radians was used as a threshold.
Nonlinear optical processes at long wavelengths utilizing magnetostatic waves

Optical phase conjugation at microwave and millimeter wavelengths offers numerous applications for communications, radar and navigation. Recently, we have examined the feasability of achieving phase conjugation at typical radar wavelengths ulitizing magnetic thin films as the active medium. Our calculations indicate that magnetic materials are unusally promising for generating phase conjugate radiation at microwave frequencies.
Obesity and pancreatic cancer: overview of epidemiologic evidence and biologic mechanisms

In the United States, pancreatic cancer is characterized by a low 5-yr survival rate of approximately 6%, fewer than 10% of patients diagnosed with localized disease and thus candidates for "curative" surgical resection, increasing incidence and few established risk factors. Similar statistics are observed for other industrialized nations. With new evidence to suggest that pancreatic cancer develops over a number of years, markers that can better identify high risk patients and are applicable to earlier diagnosis hold promise for improving these dire statistics. Obesity is one of the few modifiable risk factors that has been associated with increased risk of pancreatic cancer and also is related to increased risk of diabetes, a condition that in turn has been associated with pancreatic cancer development. Given recent data that nearly 70% of United States adults are overweight or obese, a clarification of the complex association between obesity and pancreatic cancer may disclose targets for prevention and intervention to decrease incidence and improve prognosis of this highly fatal disease. An overview of the current epidemiology and hypothesized biological mechanisms involved in the obesity-pancreatic cancer association are presented.
TH‐D‐M100J‐01: Deformable Registration of KV/MV Projection Images for Quantifying Patient Setup Offsets and Anatomical Deformations in Head and Neck IMRT

Purpose: To develop an intensity‐based deformable image registration solution for detecting and quantifying both rigid and non‐rigid variations typically seen in head‐neck IMRTtreatment, including patient position offsets, involuntary organ movements and anatomical deformations. Methods & Materials: A two‐step deformable image registration solution was developed by implementing a BSpline‐based non‐rigid representation of head‐neck anatomy and similarity metrics of mean square differences and normalized mutual information. kV and MV X‐ray projection images were registered in two successive steps. First, rigid‐body registrations were performed to determine patient position offsets in terms of translations and in‐plane rotations. The outputs were then used to initiate deformable registrations from which non‐rigid local displacements between reference and target images were extracted in the form of deformation vector fields. Validation studies were performed for patient CT simulation data, phantom images, and setup images of 12 head‐neck IMRT patients. The accuracy of the registrations were examined by comparing registration results with known variations in simulation, phantom images, a set of pre‐shift/post‐shift confirmation images, and with a feature‐based registration by subtracting coordinates of well‐identified anatomical points in patient setup images of different fractions. Results: For all three data sets with known changes, the mean (SD) error in rigid‐body registration was 0.3 mm (0.3 mm) for translations and 0.1° (0.1°) for in‐plane rotations. The error in deformable registration of image pairs with known changes was 0.5 mm (0.9 mm). For patient images with unknown non‐rigid local displacements, the agreements between deformable registration and the feature‐based registration were within 2.0 mm (96.5% of registered points). Conclusion: A 2‐step deformable image registration solution was developed and validated for registering kV/MV X‐ray projection images. The accuracy of the registration is adequate for detecting and quantifying both rigid and nonrigid variations typically seen during patient setup and target anatomy localization for head‐neck IMRT delivery.
Ultra-violet absorption of living cells.

ULTRA-VIOLET light has been used in microscopy mainly because it makes possible the study of the distribution in cells of absorbing substances, such as nucleic acids, proteins and organic iodine compounds. There has, however, been controversy about the ultra-violet absorption of living cells since Brumberg and Larionow1 questioned the findings of earlier workers2 and suggested that living cells have only a very low absorption around 2600 A., which increases markedly after a few minutes irradiation. The elegant photographs of Ludford, Smiles and Welch3, on the other hand, indicate that fresh cells of the Rb tumour show marked nuclear and cytoplasmic absorption when first observed at 2570 A. and 2750 A.
Does automation bias decision-making?

Computerized system monitors and decision aids are increasingly common additions to critical decision-making contexts such as intensive care units, nuclear power plants and aircraft cockpits. These aids are introduced with the ubiquitous goal of “reducing human error”. The present study compared error rates in a simulated flight task with and without a computer that monitored system states and made decision recommendations. Participants in non-automated settings out-performed their counterparts with a very but not perfectly reliable automated aid on a monitoring task. Participants with an aid made errors of omission (missed events when not explicitly prompted about them by the aid) and commission (did what an automated aid recommended, even when it contradicted their training and other 100% valid and available indicators). Possible causes and consequences of automation bias are discussed
Distance perception in real and virtual environments

We conducted three experiments to compare distance perception in real and virtual environments. In Experiment 1, adults estimated how long it would take to walk to targets in real and virtual environments by starting and stopping a stopwatch while looking at a target person standing between 20 and 120 ft away. The real environment was a large grassy lawn in front of a university building. We replicated this scene in our virtual environment using a nonstereoscopic, large-screen immersive display system. We found that people underestimated time to walk in both environments for distances of 40 to 60 ft and beyond. However, time-to-walk estimates were virtually identical across the two environments, particularly when people made real environment estimates first. In Experiment 2, 10- and 12-year-old children and adults estimated time to walk in real and virtual environments both with and without vision. Adults underestimated time to walk in both environments for distances of 60 to 80 ft and beyond. Again, their estimates were virtually identical in the real and virtual environment both with and without vision. Twelve-year-olds' time-to-walk estimates were also very similar across the two environments under both viewing conditions, but 10-year-olds exhibited greater underestimation in the virtual than in the real environment. A third experiment showed that adults' time-to-walk estimates were virtually identical to walking without vision. We conclude that distance perception may be better in virtual environments involving large-screen immersive displays than in those involving head-mounted displays (HMDS).
A 335 GHz quasi-optical Schottky receiver

A quasi-optical Schottky receiver based on an integrated planar antenna-mixer structure has been developed and tested at 335 GHz. The receiver antenna is based on the quasi-integrated horn antenna with 23 dB directivity. At room temperature, the measured DSB antenna-mixer conversion loss and noise temperature at 335 GHz are 8.5 dB and 1750 K, respectively. This simple and tunerless design has a noise figure within 1 dB of the best tuned room temperature waveguide mixer using a similar planar GaAs Schottky diode. >
Sulfur isotope evidence for regional recharge of saline water during continental glaciation, north-central United States

Sulfate concentrations in ground water from the Cambrian-Ordovician aquifer of south-eastern Wisconsin and northern Illinois increase up to hundreds of times where the aquifer is confined beneath the Maquoketa Shale. There is no sulfate source in the aquifer or overlying rocks except for minor amounts of finely disseminated pyrite. Coinciding with increasing sulfate concentrations, {delta}{sup 34}S of the dissolved sulfate increases from less than {minus}5{per thousand} in the unconfined part of the aquifer to a nearly constant value of +20{per thousand} where the aquifer is confined and where sulfate reduction is minimal. The most likely source for this isotopically heavy sulfate is ground water associated with Silurian evaporites under Lake Michigan. It is uncertain if the sulfate-rich water was emplaced in pulses or mostly during the last glaciation.
Effect of eicosapentaenoic acid on the proliferation and incidence of apoptosis in the colorectal cell line HT29

Fish oil has been shown to reduce the induction of colorectal cancer in animal models by a mechanism which may involve suppression of mitosis, increased apoptosis, or both. We used the human colonic adenocarcinoma cell line HT29 to explore the effects of the long-chain n-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) on cell proliferation and death in vitro. Cells were cultured in media containing EPA at 5, 10, and 15 μg/mL. Cell number and thymidine incorporation were used to quantify proliferation, and cell cycle effects were studied using flow cytometry. Gel electrophoresis, annexin-V binding, and morphological criteria were used to characterize apoptosis. Adherent cells and freely floating detached cells were treated as two distinct populations. In the presence of EPA at 10 and 15 μg/mL there was a marked reduction in the growth rate of adherent HT29 colonies, owing to an increased detachment of adherent cells. After treatment with 10 or 15 μg/mL EPA the proportion of adherent cells in S-phase increased, indicating either a block in late S-phase or early G2. Floating cells showed evidence of extensive DNA cleavage, but the proportion of floating cells with sub G0 DNA content declined on treatment with 10 or 15 μg/mL EPA even though the number of floating cells increased. We conclude that EPA does not inhibit mitosis of adherent cells, but increases the rate at which they become detached from the substrate, probably at an early stage in the initiation of apoptosis. This mechanism may be analogous to “anoikis”, or induction of apoptosis in response to loss of cell contact, and may contribute to the anticarcinogenic effects of fish oil in vivo.
Democracy and the press: A comparative analysis of pluralism in the international print media

Abstract The relationship between democracy and press pluralism is assessed in seven countries: China, Colombia, Egypt, Germany, India, Lithuania, and Russia. The term “pluralism” is defined as the extent to which diverse and competing views appear in the content of the mainstream press on a given news topic. Content analysis of 2,172 articles from the 10 largest newspapers in each country, published in the first months after the September 11, 2001 terrorist attacks, is used to evaluate the level of press pluralism. The main indicator of democracy is based on data from the Freedom House organization, though other democracy indexes are considered. Previous studies have offered conflicting views on the relationship between democracy and press pluralism. Although this study finds mixed results, the general tendency, which is based on 10 major news issues surrounding the events of 9/11, supports the perspective that democracy is not always positively associated with press pluralism. Much of the debate over 9/11 in countries ranked as highly democratic was less pluralistic than in countries with weaker democratic institutions.
Propagation of weak waves in elastic-plastic solids

Abstract Wave fronts admitting discontinuities only in the derivatives of the dependent variables are by convention called ‘weak’ waves. For the special case of discontinuous first-order derivatives, the fronts are customarily called ‘acceleration’ waves. If the governing equations are quasi-linear, then the weak waves are necessarily characteristic surfaces. Sometimes, these surfaces are also referred to as ‘singular surfaces’ of order r ⩾ 1, where r stands for the order of the first discontinuous derivatives. This latter approach is adopted in this paper and applied to governing equations which form a set of first-order quasi-linear hyperbolic equations. When these equations are written in terms of singular surface coordinates, simplification occurs upon differencing equations written on the front and rear sides of the surface: a set of algebraic (‘connection’) equations is generated for the discontinuities in the normal derivatives of the dependent variables across the surface. When a similar operation is performed on the governing equations written for second-order derivatives, a set of first-order differential (‘transport’) equations is generated. This paper treats the problem of the propagation of acceleration waves in an elastic-plastic strain-hardening rate-independent solid. The homogeneous connection equations provide an expression for the wave speeds, and the transport equations are integrated for the case of plane wave propagation in a homogeneously pre-stressed medium to obtain a solution for the change in the strength of the discontinuity. For particular examples of uniaxial and pure shear pre-stress, it is found that the second derivative of the effective-stress, effective-strain function plays a significant role in the attenuation of the wave, the decay being more pronounced as the derivative increases. Combined geometrical and material attenuation effects are found for weak waves which propagate cylindrically outward into a medium which is homogeneously pre-stressed along the cylinder axis. It is found that geometrical effects dominate until the wave has propagated a distance greater than ten times the radius of the cylinder.
Design Optimization for Improved Soft In-Plane Tiltrotor Aeroelastic in Airplane Mode

This paper examines the influence of parametric variation in individual rotor/wing design variables on whirl flutter stability improvements of a soft in-plane tiltrotor. This is followed by the use of formal gradient-based design optimization. The simulations are based on a full-scale soft in-plane Boeing model 222 rotor on a semispan wing. For this baseline configuration, the flatwise flexibility and chordwise flexibility are both outboard of the pitch bearing and produce destabilizing pitch-flap and pitch-lag couplings. The most influential rotor parameter in improving flutter stability characteristics is the distribution of flatwise flexibility vis-a-vis the pitch bearing, and large improvements are observed when flatwise flexibility is moved inboard. However, this can result in a large increase in lag frequency and turn the design into a stiff in-plane configuration. Using frequency constraints during optimization of rotor parameters and carefully selecting the airspeed range over which optimization is conducted results in improvement in subcritical wing mode damping and increase in critical flutter speed. Other rotor parameters changes that have some benefit are reduction in overall chordwise stiffness, positive increase in pitch-flap and pitch-lag coupling, and increase in control system stiffness. Wing design parameters are unable to increase the critical flutter speed but can improve the subcritical damping, primarily through an increase in wing torsion frequency and a simultaneous reduction in wing beam mode frequency. Optimization using a combination of rotor/wing design parameters yields a 35 kt increase in whirl flutter speed (from 390 to 425 kt) and an increase in subcritical damping from less than 1 % to in excess of 2% critical.
The influence of corticosteroids and topical indomethacin on sunburn erythema.

The extent to which topical and intradermal corticosteroids and topical indomethacin suppress sunburn erythema was investigated in human volunteers. Both agents retarded the onset and decreased the magnitude of delayed erythema. Suppression by corticosteroids was not demonstrable with ultraviolet doses larger than 2 MEDs (minimal erythema dose). Below 2 MEDs, topical betamethasone valerate produced a dose-related suppression of erythema. Indomethacin was more effective and produced a measurable dose-dependent suppression against 3 and 6 MEDs. Despite significant inhibition of erythema. Sunburn damage to epidermal cells was not altered by these drugs.
Sensor configuration selection for discrete-event systems under unreliable observations

Algorithms for counting the occurrences of special events in the framework of partially-observed discrete-event dynamical systems (DEDS) were developed in previous work. Their performances typically become better as the sensors providing the observations become more costly or increase in number. This paper addresses the problem of finding a sensor configuration that achieves an optimal balance between cost and the performance of the special event counting algorithm, while satisfying given observability requirements and constraints. Since this problem is generally computational hard in the framework considered, a sensor optimization algorithm is developed using two greedy heuristics, one myopic and the other based on projected performances of candidate sensors. The two heuristics are sequentially executed in order to find best sensor configurations. The developed algorithm is then applied to a sensor optimization problem for a multi-unit-operation system. Results show that improved sensor configurations can be found that may significantly reduce the sensor configuration cost but still yield acceptable performance for counting the occurrences of special events.
Contested norms in new-adopter states : international determinants of LGBT rights legislation.

This article is concerned with the question of why lesbian, gay, bisexual, and trans (LGBT) rights legislation is introduced at higher levels in some cases and less so in others. To address this pu...
Relaxation of a family of broken-bond crystal-surface models

We study the continuum limit of a family of kinetic Monte Carlo models of crystal surface relaxation that includes both the solid-on-solid and discrete Gaussian models. With computational experiments and theoretical arguments we are able to derive several partial differential equation limits identified (or nearly identified) in previous studies and to clarify the correct choice of surface tension appearing in the PDE and the correct scaling regime giving rise to each PDE. We also provide preliminary computational investigations of a number of interesting qualitative features of the large-scale behavior of the models.
Whole Lake Fluridone Treatments For Selective Control of Eurasian Watermilfoil: II. Impacts on Submersed Plant Communities

ABSTRACT The aquatic herbicide fluridone is being used in northern tier states to selectively control the submersed exotic species Eurasian watermilfoil (Myriophyllum spicatum L.) growing in lakes and reservoirs. Reliable quantitative information linking changes in the submersed plant community following fluridone applications is limited, particularly with respect to water residue records. Therefore, a study was conducted to investigate the effect of low-dose fluridone treatments on the submersed plant communities in four lakes in Michigan. The overall study objective was to determine whether submersed plant species diversity and frequency were impacted by low-dose fluridone applications in the year of treatment, when targeting a whole lake for Eurasian watermilfoil control. The primary objectives of this portion (part II) of the overall study was to determine fluridone effectiveness on the exotic submersed species Eurasian watermilfoil (Myriophyllum spicatum L.) and to evaluate shifts in plant species di...
A solid state modulator for driving SLAC 5045 klystrons

Summary form only given. A test is ongoing at the Stanford Linear Accelerator Center (SLAC) where a solid state induction modulator is driving a SLAC 5045 Klystron. The modulator generates a 22kV, 6kA pulse which is stepped up by a 15:1 transformer that is a part of the Klystron pulse tank. The modulator's pulse duration is adjustable up to the volt-second limit of its cores, and it is capable of a pulse repetition frequency up to 120 Hz. The modulator's design, construction, and the experimental results are the focus of this paper.
Auditory response to intracochlear electric stimuli following furosemide treatment

The influence of functional hair cells on electrical stimulation of the auditory nerve is an important issue as individuals with significant residual hearing are now cochlear implant candidates. Previous work has shown that chemical deafening during the course of acute experiments changes the auditory nerve's responses to electrical stimulation [Third Quarterly Progress Report, NIH contract N01-DC-9-2106 (2000), Final Report, NIH Contract N01-DC-9-2106 (2002)]. This study extended that work by investigating the changes and subsequent recovery following furosemide injections which reversibly impair hair-cell function [Hear. Res. (1980) 79-89; Hear. Res. 14 (1984) 305-314, J. Physiol. 347 (1984) 685-696; Hear. Res. 71 (1993) 202-207]. Acoustic sensitivity of guinea pig subjects was repeatedly monitored with the click-evoked compound action potential. Responses to single biphasic electric pulses and biphasic electric pulse trains delivered by a monopolar intracochlear electrode were also repeatedly assessed using the electrically evoked compound action potential (ECAP). Our measures demonstrated a clear relationship between the state of hair-cell function and ECAP responses, as changes in the latter coincided with the loss or recovery of acoustic sensitivity. ECAP growth functions demonstrated increased slope and increased maximum (saturation) amplitude. Both trends were reversible and followed approximately the time course of post-furosemide hearing recovery. Additional changes were observed using electric pulse-train stimulation: (1) the magnitude of ECAP amplitude alternation (observed in response to successive stimulus pulses) increased, (2) the degree of ECAP adaptation (measured 80-100 ms after pulse-train onset) increased, and (3) the degree of refractoriness (measured by the ratio of ECAP amplitudes to the second and first pulses) tended to increase. All these trends are consistent with the hypothesis that functional hair cells desynchronize the population of auditory nerve fibers, thereby changing the electrically evoked responses. Viable hair cells may therefore provide positive effects on auditory response to electric stimuli delivered to implant patients with residual hearing, as they may enhance the random activity of the stimulated nerve.
Interest Rates in the North and Capital Flows to the South: Is There a Missing Link?

Qualitative accounts have long emphasized the level of interest rates in the advanced industrial countries as a determinant of capital flows to emerging markets and spreads on external debt. Curiously, econometric studies relying on disaggregated data have lent little support to this hypothesis. Upon modelling the issue and pricing decisions jointly, we confirm that global credit conditions have an important impact on the market for developing-country debt. US rates have a negative impact on the demand by international investors for fixed-rate issues by Latin American borrowers, as predicted by the search-for-yield hypothesis. The same effect is apparent for East Asian floating-rate issues, although the evidence there is not as robust. But, whatever the region, this effect is evident only upon controlling for the impact of US interest rates on the decision of developing-country borrowers to issue debt.
Tree genotype and genetically based growth traits structure twig endophyte communities

Premise of the study Fungal endophytes asymptomatically inhabit plant tissues where they have mutualistic, parasitic, or commensal relationships with their hosts. Although plant-fungal interactions at the genotype scale have broad ecological and evolutionary implications, the sensitivity of endophytes in woody tissues to differences among plant genotypes is poorly understood. We hypothesize that (1) endophyte communities in Populus angustifolia (Salicaceae) twigs vary among tree genotypes, (2) endophyte variation is linked to quantitative tree traits, and (3) tree genotype influences interspecific fungal interactions. Methods Endophytes were isolated from twigs of replicated P. angustifolia genotypes in a common garden and characterized with PCR-RFLP and DNA sequencing. Twig length and diameter, aboveground tree biomass, and condensed tannins were also quantified. Key results (1) Aspects of fungal community structure, including composition and total isolation frequency (i.e., abundance), varied among genotypes. (2) Aboveground biomass and twig diameter were positively associated with isolation frequency and covaried with composition, whereas twig length and condensed tannin concentration were not significantly correlated to endophytes. (3) Fungal co-occurrence patterns suggested negative species interactions, but the presence of significant co-occurrences was genotype dependent. Conclusions The species is often assumed to be the most important ecological unit; however, these results indicate that genetically based trait variation within a species can influence an important community of associated organisms. Given the dominance of plants as primary producers and the ubiquity of endophytes, the effect of host genetic variation on endophytes has fundamental implications for our understanding of terrestrial ecosystems.
Influence of Sowing Date on Emergence Characteristics of Maize Seed Coated with a Temperature-Activated Polymer

May for the northern part of the state. In terms of grain yield, the optimum time for planting corn in southern Cold, wet soils, coupled with a short growing season, create a Minnesota is considered to be late April to early May narrow window of optimum time for planting corn (Zea mays L.) in the northern Corn Belt. Temperature-activated polymer (TAP) (Hicks et al., 1977). Although in some years soil tempercoatings designed to inhibit planted seed from imbibing water until atures are warm enough to plant corn as early as 20 adequate soil temperatures are reached to promote germination and April in southern Minnesota and 25 April in northern emergence may offer potential for planting corn exceptionally early. parts of the state, generally about 50% of the land area A study from 2000 to 2002 was conducted in west central Minnesota devoted to corn production is sown by May 11 (Hardon a Barnes soil (Calcic Hapludoll) to determine the potential for man and Gunsolus, 2002). Delaying corn planting beearlier-than-average planting of TAP-coated corn seed. The objective yond an optimum period can result in substantial yield was to compare emergence characteristics of coated and uncoated loss. It has been suggested that in Minnesota, for each hybrid corn planted early and at a near-average planting date. Seed day corn seeding is delayed between 1 May and the end planted 29 Mar. 2000 and 24 Apr. 2002 remained in the soil for as of the month, there is approximately 0.5% d 1 yield loss long as 26 to 32 d before emerging. In these instances, stands from TAP-coated seed, which ranged from 60 to 90% of seed planted, (Hardman and Gunsolus, 2002). were generally greater than those of uncoated seed, which ranged One of the greatest barriers preventing early corn from 49 to 68%. Stand establishment and time required to obtain planting in the northern Corn Belt is cold, wet soils. 50% and from 10 to 90% emergence for most early planted coating This can be problematic where heavy soils predominate hybrid seed combinations were similar to uncoated seed planted at and conservation tillage practices are used (Gupta et near-average planting dates of 1, 14, and 16 May in 2000, 2001, and al., 1988; TeKrony et al., 1989). Temperature is the 2002, respectively. When both coated and uncoated seed were sown primary factor affecting corn germination and seedling at an average planting date, stand establishment was similar, but emergence, although soil moisture is also an important emergencefor coatedseed wasgenerallydelayed. Resultsof thisstudy factor (Schneider and Gupta, 1985). During spring indicate that TAP coatings protected seeds from injury caused by planting in the northern fringes of the Corn Belt, soils extended exposure to cold soils, and therefore, might be a useful management tool for early corn planting. are often at or near field capacity for moisture (Dwyer et al., 2000). Therefore, lack of soil moisture is typically not a primary deterrent of emergence. Planting corn too early can result in seeds imbibing water but not
Efficient Annotation of Vesicle Dynamics Video Microscopy

We describe an algorithm for the efficient annotation of events of interest in video microscopy. The specific application involves the detection and tracking of multiple possibly overlapping vesicles in total internal reflection fluorescent microscopy images. A statistical model for the dynamic image data of vesicle configurations allows us to properly weight various hypotheses online. The goal is to find the most likely trajectories given a sequence of images. The computational challenge is addressed by defining a sequence of coarse-to-fine tests, derived from the statistical model, to quickly eliminate most candidate positions at each time frame. The computational load of the tests is initially very low and gradually increases as the false positives become more difficult to eliminate. Only at the last step are state variables estimated from a complete time-dependent model. Processing time thus mainly depends on the number of vesicles in the image and not on image size.