cssi/SciSciGPT-SciSciNet huggingface dataset:
The relationship of energy flow at the magnetopause to geomagnetic activity

Properties of the energetic electron (E ≳ 200 keV) magnetopause layer along the distant magnetotail have been studied with Caltech instrumentation aboard IMP-8 for approximately 60 spacecraft orbits. The cross-sectional area of the layer appears to increase by a factor of ∼ 5 with increasing geomagnetic activity, and the average unidirectional electron flux within the layer increases by a factor of ∼ 4. The energy carried by electrons ≳ 200 keV ranges from ∼ 10^(14) ergs sec^(−1) to ∼ 10^(15) ergs sec^(−1). Extrapolation to include all electrons > 1 keV suggests total energy flow ranging from ∼ 3×10^(15) ergs sec^(−1) at quiet times to ∼ 5×10^(18) ergs sec^(−1) at magnetically disturbed times.
Skeletal tissue growth, differentiation and mineralization in the NASA Rotating Wall Vessel

The NASA Rotating Wall Vessel (RWV) is a device that creates a unique environment that supports three-dimensional tissue growth, a heightened level of cell differentiation and randomizes the position of the downward gravitational force on cells. Embryonic bone formation encompasses a cascade of chondrogenic and osteogenic events, which can be altered by changes in gravitational loading. These studies were conducted to determine if the chondrogenic cascade in bone formation would be enhanced or hindered in the unique culture environment of the RWV. Embryonic mouse pre-bone tissues were placed in the RWV at one of four different stages of chondrogenesis, ranging from undifferentiated mesenchyme cells to chondrocytes on the verge of undergoing terminal chondrocyte differentiation. After culture, tissues were analyzed for their size, the amount of alkaline phosphatase (ALP) activity and their ability to form a mineralized matrix. Tissue consisting of cells at the early phase of chondrogenesis grew very little and did not differentiate or mineralize when cultured in the RWV. Some tissues were cultured for short periods in the RWV then cultured in standard culture dishes (SCD). Following this culture regime, the cartilage grew only a small amount, but alkaline phosphatase activity increased, and some mineralized regions formed. The pattern of mineralization was abnormal, with two mineralized zones at each end of the cartilage instead of a single central zone. Tissues that were at the three more advanced stages of chondrogenesis when placed in the RWV showed substantial growth, differentiation and mineralization. Mineralization patterns in these older tissues was normal. Tissues at the oldest stage of chondrogenesis showed more growth and as much or more mineralization as tissue cultured only in SCD. These data suggest that exposure to the RWV at early stages of chondrogenesis severely limits the ability for cartilage growth and yields abnormal downstream morphogenesis. However, at later stages of chondrogenesis, the RWV environment may be beneficial and enhance growth and development. Future studies to characterize intercellular signaling molecules and gene expression activities of chondrocytes in the RWV will be valuable for understanding the mechanism of skeletogenesis.
Modalities for building relationships with handheld computer agents

In this paper we describe the design of a relational agent interface for handheld computers and the results of a study exploring the effectiveness of different user-agent interaction modalities. Four different agent output modalities-text only, static image plus text, animated, and animated plus nonverbal speech-are compared and their impact on the ability of the agent to establish a social bond with the user, the perceived credibility of information delivered, and user acceptance is evaluated. Subjects ranked the two animated versions of the system higher on all measures.
Translucency of Human Dental Enamel

Translucency of human dental enamel was determined by total transmittance of wavelengths from 400 to 700 nm. The transmission coefficient at 525 nm was 0.481 mm-1. Total transmission of light through human dental enamel increased with increasing wavelength. Human tooth enamel is more translucent at higher wavelengths. The translucency of wet human enamel and enamel after dehydration was also measured by total transmittance. The transmission coefficient at 525 nm decreased from 0.482 to 0.313 mm-1 after dehydration and was reversed on rehydration. The decrease in translucency occurred as a result of the replacement of water around the enamel prisms by air during dehydration.
Wingate performance and surface EMG frequency variables are not affected by caffeine ingestion

The ergogenic effect of caffeine and its mechanism of action on short-term, high-intensity exercise are controversial. One proposed mechanism is caffeine’s stimulatory effect on the central nervous...
Lysis of resealed erythrocyte ghosts by photoactivated tetrapyrroles: Estimation of photolesion dimensions

1. Resealed erythrocyte ghosts containing Na+ and glucose-6-P (G6P) as markers of membrane integrity were used as a model system for probing the damaging effects of photoactivated tetrapyrroles on cell membranes. 2. Continuous blue-light irradiation of bilirubin (BR)-sensitized and protoporphyrin (PP)-sensitized ghosts made them progressively more permeable to Na+, the cation emerging well ahead of G6P. 3. G6P efflux occurred abruptly after a lag period and resembled an all-or-none process. 4. These and other results suggest that a relatively subtle structural modification (possibly in some crucial protein(s) is sufficient for Na+ release, whereas gross disruption of the bilayer (probably by free-radical lipid peroxidation) is necessary for G6P release. 5. The dimensions of the G6P-releasing photolesions were estimated by density floatation centrifugation, using saccharides of increasing molecular size. Both BR and PP produced pores greater than 11 A but less than 42 A in diam., which is considerable smaller than the size range estimated in hypotonically lysed ghosts.
Spectrophotometric determination of the number of absorbing species in solution

Abstract Equations for the determination of the number of absorbing species in solution were developed by a new procedure. Their use was demonstrated for the iron(III)-thiocyanate and bismuth-iodide systems. The application of the method for absorbing metals and ligands, the limits of the method and its importance for the investigation of solutions are discussed.
The Influence of Vocabulary Size, Phonotactic Probability, and Wordlikeness on Nonword Repetitions of Children With and Without Specific Language Impairment

Research has shown that children repeat high-probability phoneme sequences more accurately than low-probability ones. This effect attenuates with age, and its decrease is predicted by developmental...
Next-to-next-to-leading-order ϵ expansion for a Fermi gas at infinite scattering length

We extend previous work on applying the $ϵ$ expansion to universal properties of a cold, dilute Fermi gas in the unitary regime of infinite scattering length. We compute the ratio $\ensuremath{\xi}=\ensuremath{\mu}∕{ϵ}_{\mathrm{F}}$ of chemical potential to ideal gas Fermi energy to next-to-next-to-leading-order (NNLO) in $ϵ=4\ensuremath{-}d$, where $d$ is the number of spatial dimensions. We also explore the nature of corrections from the order after NNLO.
A novel biomimetic actuator system

The design of a biomimetic actuation system which independently modulates position and net stiffness is presented. The system is obtained by antagonistically pairing contractile devices capable of modulating their rate of geometric deformation relative to the rate of deformation of a passive elastic storage element in series with the device's input source. A mechanical model is developed and the properties of the device are investigated. The theoretical results developed are then compared with experimental evidence obtained from a simple prototype model of the system.
Training of symbolic play

Attitudes about the role of the teacher in children's play have undergone a dramatic change in the past several decades. The children's teachers were first shown how to use several types of play training. Play training has been found to result in gains in a variety of variables, including IQ scores, creativity, perspective taking, and language development. Most play training procedures have focused on sociodramatic play, an advanced form of symbolic play in which groups of children plan and carry out cooperative dramatizations. Modeling was one of the procedures used in the Smilansky study. Variations of this procedure were also used in many subsequent play training studies. Verbal guidance was the other type of training used by Smilansky. Thematic-fantasy training was developed by Eli Saltz and James Johnson for use in a series of play training studies. The purpose of imaginative play training is to enhance children's make-believe skills so that they can play more imaginatively and creatively.
The semistable reduction problem for the space of morphisms on ℙn

We restate the semistable reduction theorem from geometric invariant theory in the context of spaces of morphisms from Pn to itself. For every complete curve C downstairs, we get a Pn-bundle on an abstract curve D mapping finite-to-one onto C, whose trivializations correspond to not necessarily complete curves upstairs with morphisms corresponding to identifying each fiber with the morphism the point represents. Finding a trivial bundle is equivalent to finding a complete D upstairs mapping finite-to-one onto C; we prove that in every space of morphisms, there exists a curve C for which no such D exists. In the case when D exists, we bound the degree of the map from D to C in terms of C for C rational and contained in the stable space.
What gets suppliers to play and who gets the pay? On the antecedents and outcomes of collaboration in retailer-supplier dyads

Purpose – The purpose of this paper is to adopt and contribute to the further development of the relational view by examining the drivers of retailer-supplier collaboration and its effect on the performance of both the retailer and the supplier. Design/methodology/approach – The paper draws its conclusions from a structural analysis of dyadic survey data collected from consumer packaged goods suppliers and retailers in Brazil. In addition, objective retailer performance measures (retailer in-stock performance) are included in the data set. Findings – The results indicate that a supplier's customer orientation is an important determinant of supplier relationship-specific investments and, ultimately, supply chain collaboration. The empirical results also indicate that retailers stand to benefit the most from a supplier's collaborative efforts. In addition, there is evidence that a supplier's customer orientation is positively related to its own performance. Research limitations/implications – The limited sa...
Fuzzy inference and its applicability to control systems

Abstract Two fuzzy reasoning methods: the linguistic synthesis method and a new model are studied by being applied to construct fuzzy controllers to a second-order, nonlinear system-Cart-pole system. In the former method, several implication operators are used. In order to investigate the applicabilities and robustnesses of these two methods, the parameters of the controlled process are changed. The advantages of the new model are shown through the procedure of generating the fuzzy controller and the results of fuzzy control system.
Environmental Problems and Policy: 2000 -2050

The next 50 years will see more use of market-based tools for environmental protection. Regulatory authorities everywhere will require polluters to report emissions. Authority will leak away from national governments; some will be devolved to lower levels of government, but some will be lost to international bodies. Environmental conditions will continue to improve steadily in developed countries. The developing countries will be less fortunate; at least until rising incomes provide the impetus for stricter standards. Some losses will be irreversible, as with species that are extinguished.
Flavor and CP violating Z exchange and the rate asymmetry in B→φKS

Abstract Recent measurements of time dependent CP asymmetry in B → φK S , if confirmed, would indicate a new source of CP violation. We examine flavor violating tree-level Z currents in models with extra down-type quark singlets that arise naturally in string compactified gauge groups like E 6 . We evaluate the new operators at the scale μ≈ O (m b ) in NLO, and using QCD improved factorization to describe B → φK S , find the allowed range of parameters for ρ and ψ , the magnitude and phase of the flavor violating parameter U bs . This allowed range does satisfy the constraint from flavor changing process b → s l + l − . However, further improvement in measurement of these rates could severely constrain the model.
Surface valence states and stoichiometry of non-superconducting and superconducting FeTe films

Abstract We report the surface electronic structure and stoichiometry of FeTe films following the incorporation of oxygen by three different methods: air exposure, dry oxygen exposure and low temperature oxygen annealing. X-ray photoemission experiments show that oxygen incorporation changes the initial valence state of Fe from 0 to mainly 3+. We also observe that the Te changes valence from initially 0 to mixed 0 and 4+. The rate of valence changes is seen to depend on the method of incorporation. In addition, it is observed that the surface of the FeTe films is left in a Te deficient state following any type of exposure to oxygen.
Gravity effects on damping of a space structure with pinned joints

An area of concern for the design of large space structures is the amount of structural damping that will be present. The joints used to assemble a large, light-weight structure like the space station will provide some damping; however, an accepted methodology for predicting joint damping is yet to be established. This paper documents a research effort at Utah State University to better understand joint damping in large space structures. A miniature tetrahedral truss was constructed that uses pinned joints. A large tip mass was attached to the truss to lower the natural frequency to a range associated with the space station. Considerable ground testing has been conducted to characterize the damping of the truss in a l-g environment in different orientations and in a vacuum. It was determined that the contribution of air to structural damping was insignificant for this truss. These experiments show that gravity can dramatically influence the damping produced.
Variability in cerebral oxygen delivery is reduced in premature neonates exposed to chorioamnionitis.

Premature infants exposed to chorioamnionitis are at increased risk for periventricular leukomalacia (PVL) and intraventricular hemorrhage (IVH), lesions that may result from inflammation and/or fluctuations in cerebral blood flow. The effect of chorioamnionitis on near-infrared spectroscopy (NIRS) measures of cerebral oxygen delivery has not been evaluated previously. Forty-nine infants born at 25–31 6/7 wk gestation underwent NIRS examination on d 1, 2, 3, and 7 of life. Variability in NIRS tracings was analyzed by partitioning each tracing into three components: long-term, intermediate, and short-term variability; the latter two components were analyzed. Chorioamnionitis-exposed infants manifest reduced intermediate variability in cerebral oxygenated and deoxygenated Hb but not total Hb. Infants with severe IVH/PVL had the lowest intermediate variability on d 1. Short-term variability was similar between chorioamnionitis-exposed and unexposed infants, and between infants with versus without severe IVH or PVL. We conclude that intermediate-term variability in NIRS cerebral oxygen delivery is reduced in chorioamnionitis-exposed infants. We speculate that intermediate variability represents the important time frame for evaluating the pathogenesis of perinatal brain injury. Further studies are needed to determine how these findings relate to cerebral blood flow autoregulation and oxygen utilization in premature infants.
Hydridic character of early transition metal hydride complexes

Abstract The cendency of transition metal hydride complexes to behave as true hydrides, as measured by ability to reduce ketones, appears to depend strongly on the position of the metal in the Periodic Table; the strongest such behavior is exhibited by complexes of metals furthest to the left in the transition series.
The Quest for Diversity in Christian Higher Education: Building Institutional Governance Capacity

Social justice pertaining to diversity issues in higher education grips the nation, yet Christian higher education (CHE) has moved slowly to address the diversity in our institutions and society. Christian higher education faces the same challenges with growing diversity as secular higher education. Diversity impacts every aspect of institutional life from student enrollment, faculty engagement, and curricular development to board governance and institutional outcomes. Research has focused on disparities in CHE in areas ranging across access, enrollment, graduation rates, faculty diversity, and administrative leadership. Yet, there has been limited inquiry into the role of governing boards in addressing diversity from a comprehensive, institutional perspective. This article examines the intersection of diversity, social justice, and governance in the context of Christian higher education. The authors argue the institution's theological foundations provide a strong biblical and moral rationale for addressi...
HIV knowledge and behaviors of incarcerated youth: A comparison of high and low risk locales

Abstract Incarcerated adolescents comprise a group at high risk of HIV infection because they engage in substantially more HIV-related sexual and drug behaviors than the general adolescent population. There is, however, little information on similarities and differences between adolescents incarcerated in high AIDS-prevalence geographic areas with those from low AIDS-prevalence areas. This study compared adolescents incarcerated in juvenile detention facilities in San Francisco (N = 113) and Alabama (N = 393) with respect to HIV-related knowledge, attitudes, and risk behaviors. While findings indicated that the two groups' overall knowledge levels were relatively similar, adolescents in San Francisco reported a higher prevalence of risk behaviors. These findings are discussed in terms of the development and implementation of HIV prevention programs specifically targeted toward incarcerated youths and stressing adoption of realistic risk-reduction strategies.
Effect of multiple uncertain material properties on the response variability of in-plane and plate structures

Abstract In the majority of research works on stochastic finite element analysis, the main concern is put on the effect of uncertain elastic modulus on the response variability. This is mainly due to the importance of this parameter in the stochastic response of structures but also to the difficulties in introducing other material and/or geometrical uncertain parameters in the stochastic formulation. In this paper, a formulation is suggested in order to determine the response variability of in-plane and plate structures with multiple uncertain material parameters, i.e., elastic modulus and Poisson’s ratio. To accomplish this, use is made of the general equation for n th joint moment and a polynomial expansion on the coefficients of constitutive matrix. For computational purposes, the infinite series of stochastic sub-stiffness matrices is truncated preserving sufficient accuracy. To demonstrate the validity of the proposed formulation, some numerical examples are provided and the results are compared with those obtained by means of classical Monte Carlo simulation combined with the local average scheme.
Site-Specific Hydration Status of an Amphipathic Peptide in AOT Reverse Micelles

Reverse micelles formed by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in isooctane (IO) and water have long been used as a means to provide a confined aqueous environment for various applications. In particular, AOT reverse micelles have often been used as a template to mimic membrane−water interfaces. While earlier studies have shown that membrane-binding peptides can indeed be incorporated into the polar cavity of AOT reverse micelles where they mostly fold into an α-helical structure, the underlying interactions leading to the ordered conformation are however not well understood. Herein, we have used circular dichroism (CD) and infrared (IR) spectroscopies in conjunction with a local IR marker (i.e., the C⋮N group of a non-natural amino acid, p-cyano-phenylalanine) and a global IR reporter (i.e., the amide I‘ band of the peptide backbone) to probe the conformation as well as the hydration status of an antimicrobial peptide, mastoparan x (MPx), in AOT reverse micelles of different water contents. Our...
The general relativistic hydrogen atom

The general relativistic Dirac equation is formulated in an arbitrary curved space-time using differential forms. These equations are applied to spherically symmetric systems with arbitrary charge and mass. For the case of a black hole (with event horizon) it is shown that the Dirac Hamiltonian is self-adjoint, has essential spectrum the whole real line and no bound states. Although rigorous results are obtained only for a spherically symmetric system, it is argued that, in the presence of any event horizon there will be no bound states. The case of a naked singularity is investigated with the results that the Dirac Hamiltonian is not self-adjoint. The self-adjoint extensions preserving angular momentum are studied and their spectrum is found to consist of an essential spectrum corresponding to that of a free electron plus eigenvalues in the gap (−mc2, +mc2). It is shown that, for certain boundary conditions, neutrino bound states exist.
Irradiation-induced order-to-disorder phase transformation at different temperatures in Dy2O3

Polycrystalline pellets of the rare earth sesquioxide Dy2O3 were irradiated at two temperatures (∼120 K and ∼300 K) with 300 keV Kr++ ions up to a fluence of 1 × 1020 Kr/m2. The crystal structure of the irradiated Dy2O3 was observed to change from an ordered cubic bixbyite structure (so-called C-type rare earth sesquioxide structure) to a disordered, anion-deficient fluorite structure. A relatively low ion dose (∼2.5 displacements per atom [dpa]) was sufficient to induce a complete order-to-disorder (O-D) phase transformation at cryogenic temperature (∼120 K) irradiation, while at room temperature (∼300 K) a higher dose (∼25 dpa) produced only a partial O-D phase transformation.
Use of Parents, Sibs, and Unrelated Controls for Detection of Associations between Genetic Markers and Disease

Detecting the association between genetic markers and complex diseases can be a critical first step toward identification of the genetic basis of disease. Misleading associations can be avoided by choosing as controls the parents of diseased cases, but the availability of parents often limits this design to early-onset disease. Alternatively, sib controls offer a valid design. A general multivariate score statistic is presented, to detect the association between a multiallelic genetic marker locus and affection status; this general approach is applicable to designs that use parents as controls, sibs as controls, or even unrelated controls whose genotypes do not fit Hardy-Weinberg proportions or that pool any combination of these different designs. The benefit of this multivariate score statistic is that it will tend to be the most powerful method when multiple marker alleles are associated with affection status. To plan these types of studies, we present methods to compute sample size and power, allowing for varying sibship sizes, ascertainment criteria, and genetic models of risk. The results indicate that sib controls have less power than parental controls and that the power of sib controls can be increased by increasing either the number of affected sibs per sibship or the number of unaffected control sibs. The sample-size results indicate that the use of sib controls to test for associations, by use of either a single-marker locus or a genomewide screen, will be feasible for markers that have a dominant effect and for common alleles having a recessive effect. The results presented will be useful for investigators planning studies using sibs as controls.
Lorcainide therapy for the high-risk patient post myocardial infarction.

Abstract Nonsustained ventricular tachycardia (VT) in the late period (7 to 21 days) after myocardial infarction (MI) is reported to be a predictor of sudden death. Patients with 3-beai VT on Holter monitoring in the late infarction period would be suspected to demonstrate electrical instability on electrophysiologic studies. Forty-seven patients were identified as having at least 3-beat VT on Holter monitoring. Eighteen patients refused electrophysiologic studies or were not referred. Eight patients died; 3 were sudden deaths in 13 ± 5 months, a 17% incidence. Twenty-nine patients underwent invasive electrophysiologic studies and 28 had inducible VT, 18 sustained and 10 nonsustained. Lorcainide prevented VT induction in 21 of the 28 patients, whereas 12 of the 22 patients studied on procainamide were protected. Lidocaine, tested in 21 patients, prevented VT induction in only 5. Lorcainide and procainamide prolonged refractoriness in those patients protected at programmed electrical stimulation (PES), whereas the QT interval was prolonged in patients in whom VT could still be induced. Twenty-seven of the 28 patients were placed on drugs predicted to be effective by PES studies, 19 on lorcainide. After a mean follow-up of 12.5 ± 4 months the patient with noninducible arrhythmia is alive and 26 of the 28 patients with inducible arrhythmia are alive and well. Two patients died, 1 of stroke and 1 of pump failure after a second MI. No sudden deaths were observed in this group. Two patients had breakthrough arrhythmias and were treated by alternative antiarrhythmic therapy that was also effective on initial electrophysiologic studies. Thus, PES studies after MI are safe and may be an effective way to determine therapy for patients in the post-MI period, identified at high risk for sudden death. Furthermore, lorcainide appears to be safe and effective when its selection is guided by electrophysiologic studies.
The trade-off between the additive complexity and the asynchronicity of linear and bilinear algorithms

Abstract It is shown that every linear algorithm that computes a set of Q linearly independent linear forms in k variables must involve at least Q log2 k - H additions and subtractions where H is a quantity that measures the asynchronicity of the algorithm. The result is extended to the evaluation of a set of bilinear forms.
On the current status of magnetorheological dampers: seismic protection of full-scale structures

Because of their mechanical simplicity, high dynamic range, low power requirements, large force capacity and robustness, magnetorheological (MR) fluid dampers have been shown to be semi-active control devices that mesh well with application demands and constraints to offer an attractive means of protecting civil infrastructure systems against severe earthquake and wind loading. Following an overview of the essential features of MR fluids, this paper discusses the current status of this new technology for seismic protection of structures, including presentation of recent laboratory studies employing a seismically-excited, scale-model building and preliminary analyses of a prototype full-scale MR damper.
Harvesting nanoscale thermal radiation using pyroelectric materials

Pyroelectric energy conversion offers a way to convert waste heat directly into electricity. It makes use of the pyroelectric effect to create a flow of charge to or from the surface of a material as a result of heating or cooling. However, existing pyroelectric energy converter can only operate at low frequency due to relatively small convective heat transfer rate between the pyroelectric materials and the working fluid. On the other hand, energy transfer by thermal radiation between two semi-infinite solids is nearly instantaneous and can be enhanced by several orders of magnitude from the conventional Stefan-Boltzmann law as the gap separating them becomes smaller than the Wien's displacement wavelength. This paper explores a novel way to harvest waste heat by combining pyroelectric energy conversion and nanoscale thermal radiation. A new device was investigated numerically by accurately modeling nanoscale radiative heat transfer between a pyroelectric element and hot and cold plates. Silica absorbing layers on top of every surface were used to further increase the net radiative heat fluxes. Temperature oscillations with time and performances of the pyroelectric converter were predicted at various frequencies. The device using 60/40 P(VDF-TrFE) achieved 0.2% efficiency and 0.84 mW/cm2 electrical power output for the cold and hot sources at 273 and 388 K, respectively. Better performances could be achieved with 0.9PMN-PT namely efficiency of 1.3% and power output of 6.5 mW/cm2 between the cold and hot sources at 283 and 383 K, respectively. These results are compared with alternative technologies and suggestions are made to further improve the device.
Effects of tail length on an escape maneuver of the Red-billed Streamertail

Sexually selected, elongated tails in birds may impair or alter naturally selected functions related to flight. The aim of this study was to test whether experimental manipulation of tail length affected the kinematics of a low-speed escape maneuver. The Red-billed Streamertail (Trochilus polytmus) has the longest tail of any hummingbird and is highly sexually dimorphic in tail length. I hypothesized that streamertails with either a long tail or with the tail removed would perform maneuvers with reduced linear and angular accelerations, relative to maneuvers performed with a short tail. Two high-speed video cameras recorded maneuvers from male and female Red-billed Streamertails under three tail length treatments: short tail, long tail, and no tail. The detailed kinematics of the maneuvers were highly variable. Whereas the birds always performed rolls (rotation about the bird’s X-axis) during the maneuver, there was variation in the relative importance of pitching motions (rotation about the Y-axis) or yawing motions (rotation about the Z-axis), with yawing rotations playing a small role in ‘pitch-roll’ turns, and pitching motions playing a small role in ‘yaw/roll’ turns. Birds missing their entire tail exhibited reduced maximum linear accelerations associated with a curving trajectory. By contrast, birds maneuvering with an elongated tail did not exhibit significantly different kinematics from the controls, suggesting that the greatly elongated tail streamers have relatively small effects on the bird’s ability to maneuver at low speeds. Based on these observations, greatly elongated tails may not pose a large cost to low-speed maneuvering flight.
Kalman-filter channel estimator for OFDM systems in time and frequency-selective fading environment

We present a Kalman-filter method for the estimation of time-frequency-selective fading channels in OFDM systems. Based on the Jakes model, an autoregressive (AR) model of the channel dynamics is built. To reduce the complexity of the high-dimensional Kalman filer for joint estimation of the subchannels, we propose to use a low-dimensional Kalman filter for the estimation of each subchannel. Then, a minimum mean-square-error (MMSE) combiner is used to refine the Kalman estimates. The per-subchannel Kalman estimator explores the time-domain correlation of the channel, while the MMSE combiner explores the frequency-domain correlation. This two-step solution offers a performance comparable to the much more complicated joint Kalman estimator.
NCI remains committed to current mammography guidelines.

The Oncologist 2002;7:170-171 www.TheOncologist.com In a world too often given to ambiguity and equivocation, let me begin here as I began my testimony before Congress several months ago on this same important public health issue. The National Cancer Institute (NCI) remains dedicated to evaluating all information on the early detection of breast cancer and to continuously improving the diagnosis and treatment of this disease to save lives. With this principle ever present during the recent controversy over mammography screening, we reaffirm the following recommendation:
Specificity of crowding response that induces sexuality in the rotifer Brachionus

Crowding induced the production of mictic (male-producing) females in Brachionus calyciflorus from two North American strains and an Australian strain. The specificity of this response to crowding was tested by culturing single individuals of a North American clone in three treatment conditions: a small volume (high density), a large volume (low density), and a large volume with a high density of an Australian clone. The results were consistent and clear in six experiments using different combinations of clones. Crowding low-density individuals of the North American strains with the Australian strain failed to induce them to produce mictic females. The mictic-female response in this treatment was similar to that in the low-density treatment, and both of these responses were significantly lower than that in the high-density treatment. Since the mictic-female response to crowding in Brachionus is mediated by a chemical produced by the rotifers themselves, the chemical inducers produced by the Australian and North American strains must be different. Taxonomically specific responses to crowding should increase fitness by assuring that sexual reproduction in the heterogonic life cycle coincides with a high population density of individuals able to mate with one another and, thus, when the production of fertilized resting eggs can be maximized. This would be especially important in plankton communities with diverse rotifer assemblages and multiple congeneric species. Otherwise, a low-density population of a species could be induced to initiate bisexual reproduction by populations of other species, curtailing its potential for population growth via female parthenogenesis and limiting its production of resting eggs in the future.
A Network Connection Proxy to Enable Hosts to Sleep and Save Energy

Billions of dollars of electricity are being used to keep idle or unused network hosts fully powered-on only to maintain their network presence. We investigate how a network connectivity proxy (NCP) could enable significant energy savings by allowing idle hosts to enter a low-power sleep state and still maintain full network presence. An NCP must handle ARP, ICMP, DHCP, and other low-level network presence tasks for a network host. An NCP must also be able to maintain TCP connections and UDP data flows and to respond to application messages. The focus of this paper is on how TCP connections can be kept alive during periods of host sleep by using a SOCKS-based approach called green SOCKS (gSOCKS) as part of an NCP. The gSOCKS includes awareness of the power state of a host. A prototype implementation of gSOCKS in a Linksys router shows that TCP connections can be preserved.
Toughness and Contact Behavior of Conventional and Low- k Dielectric Thin Films

A comprehensive indentation fracture mechanics framework is established that allows the fracture properties of thin films to be determined. The framework is composed of four stress-intensity factors characterizing the stress fields arising from (i) elastic contact, (ii) wedging, (iii) residual elastic-plastic mismatch and (iv) pre-existing film stress. The amplitudes of the stress-intensity factors depend on the deformation properties of the film and vary throughout the indentation cycle. The toughness values of a PVD alumina, for which (iii) and (iv) are dominant, and a low-k film, for which (i), (ii) and (iv) are dominant, are evaluated.
Address-Event Communication Using Token-Ring Mutual Exclusion

We present a novel Address-Event Representation (AER) transmitter circuit to communicate pulses of neural activity (spikes) within a neuromorphic system. AER circuits allow an ensemble of neurons to achieve large scale time-multiplexed connectivity through a shared communication channel. Our design makes use of token-ring mutual exclusion where two circulating tokens in a 2D array of neurons provide exclusive access to the shared channel. Compared to traditional arbitration-tree-based designs, our design has a higher throughput and lower latency during high spiking activity. This allows the circuit to serve larger neuronal densities and higher spiking activity while maintaining the temporal precision required by the system. Our design also eliminates the address line loads that restricted scalability in previous designs. In addition, our simpler circuit topology leads to area and power savings.
Target detection and counting using a progressive certainty map in distributed visual sensor networks

Visual sensor networks (VSNs) merge computer vision, image processing and wireless sensor network disciplines to solve problems in multi-camera applications by providing valuable information through distributed sensing and collaborative in-network processing. Collaboration in sensor networks is necessary not only to compensate for the processing, sensing, energy, and bandwidth limitations of each sensor node but also to improve the accuracy and robustness of the sensor network. Collaborative processing in VSNs is more challenging than in conventional scalar sensor networks (SSNs) because of two unique features of cameras, including the extremely higher data rate compared to that of scalar sensors and the directional sensing characteristics with limited field of view. In this paper, we study a challenging computer vision problem, target detection and counting in VSN environment. Traditionally, the problem is solved by counting the number of intersections of the backprojected 2D cones of each target. However, the existence of visual occlusion among targets would generate many false alarms. In this work, instead of resolving the uncertainty about target existence at the intersections, we identify and study the non-occupied areas in the cone and generate the so-called certainty map of non-existence of targets. This way, after fusing inputs from a set of sensor nodes, the unresolved regions on the certainty map would be the location of target. This paper focuses on the design of a light-weight, energy-efficient, and robust solution where not only each camera node transmits a very limited amount of data but that a limited number of camera nodes is used. We propose a dynamic itinerary for certainty map integration where the entire map is progressively clarified from sensor to sensor. When the confidence of the certainty map is satisfied, a geometric counting algorithm is applied to find the estimated number of targets. In the conducted experiments using real data, the results of the proposed distributed and progressive method shows effectiveness in detection accuracy and energy and bandwidth efficiency.
Fossil hominin shoulders support an African ape-like last common ancestor of humans and chimpanzees

Reconstructing the behavioral shifts that drove hominin evolution requires knowledge of the timing, magnitude, and direction of anatomical changes over the past ∼6–7 million years. These reconstructions depend on assumptions regarding the morphotype of the Homo–Pan last common ancestor (LCA). However, there is little consensus for the LCA, with proposed models ranging from African ape to orangutan or generalized Miocene ape-like. The ancestral state of the shoulder is of particular interest because it is functionally associated with important behavioral shifts in hominins, such as reduced arboreality, high-speed throwing, and tool use. However, previous morphometric analyses of both living and fossil taxa have yielded contradictory results. Here, we generated a 3D morphospace of ape and human scapular shape to plot evolutionary trajectories, predict ancestral morphologies, and directly test alternative evolutionary hypotheses using the hominin fossil evidence. We show that the most parsimonious model for the evolution of hominin shoulder shape starts with an African ape-like ancestral state. We propose that the shoulder evolved gradually along a single morphocline, achieving modern human-like configuration and function within the genus Homo. These data are consistent with a slow, progressive loss of arboreality and increased tool use throughout human evolution.
Automatic As-Built Generation with Utility Trenchers

The proper functioning of the subsurface infrastructure is vital for the public, industry, and government. As is demonstrated almost daily, small disruptions or malfunctions of public utilities, such as power, gas, or phone, can result in catastrophic events on local, regional, or national levels. This paper addresses a known weak point in protecting buried utilities from damage, the lack of accurate as-builts. It is suggested to take advantage of enabling technologies to automatically create as-built drawings relying on electronic sensory data collected real-time from operating machinery. A significant portion of the paper discusses the development of a spatially integrated trencher, a prototype that was subsequently used to execute field experiments. The encouraging outcome of those tests, which are supported with actual data, demonstrated the soundness of the concept and the level of accuracy that can be expected. The relevance to the industry lies in that it addresses a real and complex problem, proposing and demonstrating a workable technology to close a large gap in the way we track our subsurface infrastructure. It is hoped that researchers will be encouraged to extend the concept to other relevant applications while applying a similar rigorous method of experimental field testing.
Scaling application performance on a cache-coherent multiprocessor

Hardware-coherent, distributed shared address space systems are increasingly successful at moderate scale. However, it is unclear whether, or with how much difficulty, the performance of a load-store shared address space programming model scales to large processor counts on real applications. We examine this question using an aggressive case-study machine, the SGI Origin2000, up to 128 processors. We show for the first time that scalable performance can indeed be achieved in this programming model on a wide range of applications, including challenging kernels like FFT. However, this does not come easily, even for applications considered to be already highly optimized, and is very often not simply a matter of increasing problem size. Rather, substantial further application restructuring is often needed, which is usually quite algorithmic in nature. We examine how the restructurings compare with those needed for performance portability to shared virtual memory on clusters, and we comment on common programming guidelines for performance portability and scalability as well as on how the programming difficulty compares with that of explicit message passing. We also examine where applications spend their time on this large machine, the impact of special hardware features that the machine provides, and the impact of mapping to the network topology.
Bounded submodules of modules

Abstract Let m , n be positive integers such that m ⩽ n and k be a field. We consider all pairs ( B , A ) where B is a finite dimensional T n -bounded k [ T ] -module and A is a submodule of B which is T m -bounded. They form the objects of the submodule category S m ( k [ T ] / T n ) which is a Krull–Schmidt category with Auslander–Reiten sequences. The case m = n deals with submodules of k [ T ] / T n -modules and has been studied well. In this paper we determine the representation type of the categories S m ( k [ T ] / T n ) also for the cases where m n : It turns out that there are only finitely many indecomposables in S m ( k [ T ] / T n ) if either m 3 , n 6 , or ( m , n ) = ( 3 , 6 ) ; the category is tame if ( m , n ) is one of the pairs ( 3 , 7 ) , ( 4 , 6 ) , ( 5 , 6 ) , or ( 6 , 6 ) ; otherwise, S m ( k [ T ] / T n ) has wild representation type. Moreover, in each of the finite or tame cases we describe the indecomposables and picture the Auslander–Reiten quiver.
Fabrication of a disposable biosensor for Escherichia Coli O157:H7 detection

As the safety in the food supply becomes critical, the demand for a rapid, low-volume, and sensitive microbial detection device has dramatically increased. A biosensor based on an electrochemical sandwich immunoassay using polyaniline has been developed for detecting foodborne pathogens, such as Escherichia coli (E. coli) O157:H7. The biosensor is comprised of two types of proteins: capture protein and reporter protein. The capture protein is immobilized on a pad between two electrodes, while the reporter protein is attached to conductive polymers. After adding the sample, the target protein binds to the reporter protein and forms a sandwich complex with the capture protein. The conductive polymer that is attached to the reporter protein serves as a messenger, reporting the amount of target protein captured in the form of an electrical signal. The architecture of the biosensor utilizes a lateral flow format, which allows the liquid sample to move from one pad to another by capillary action. Experiments to evaluate the best construction materials, the optimal polyaniline and antibody concentrations, and the distance between electrodes are highlighted in this paper. Results show that the biosensor could detect approximately 7.8/spl times/10/sup 1/ colony forming unit per milliliter of E. coli O157:H7 in 10 min.
Rebels at the Gates: Civil War Battle Locations, Movement, and Openings for Diplomacy†

In this paper, I build upon the conflict management, civil war, and bargaining literatures to develop and test a theoretical model that links openings for diplomacy to where civil war battles occur and how these locations change over time. I argue that the locations and movements of civil war battles provide information to both governments and rebels that influences their willingness to engage in mediation and negotiation. By identifying how civil war battles influence the willingness of warring sides to participate in diplomacy, I suggest that it is possible to identify other windows of opportunity for effective conflict management beyond waiting for a conflict to evolve into a hurting stalemate. The results of my analysis of 46 African civil conflicts shows that battle locations, battle velocity, and battle dispersion each influence the occurrence and outcomes of peace talks.