cssi/SciSciGPT-SciSciNet huggingface dataset:
Fractographic examinations of fracture in polycrystalline S2 ice

Fractographic examinations were carried out on the fracture surfaces of both single-edge notched bend (SENB) and wedge-loaded compact tension (WLCT) specimens of S2 freshwater ice. Formvar solutions provided an effective means of making replicas that revealed various patterns of the fracture surfaces. The fracture modes consisted of both cleavage and brittle intergranular fracture, with cleavage fracture dominating. The cleavage planes of the S2 ice were mainly the {0 0 0 1} and {10¯1 1} planes under the experimental conditions for this study. Kinks forming new grain boundaries were found on the fracture surfaces of polycrystalline S2 ice for the first time. Kinking is regarded as a possible mechanism of plastic deformation for polycrystalline ice and to partially account for the high fracture energy of S2 ice found in this study.
Immunocytochemical evidence for particulate localization of phenylethanolamine-N-methyltransferase in adrenal medulla.

Abstract Previous biochemical evidence for the localization of phenylethanolamine-N-methyltransferase in adrenal medulla has indicated that this enzyme is soluble, although some workers have reported a significant amount of particulate phenylethanolamine-N-methyltransferase (Joh and Goldstein, 1973). Electron microscopic immunocytochemical study of bovine adrenal medulla has revealed a distinct particulate localization of phenylethanolamine-N-methyltransferase in association with chromaffin granules. It is therefore suggested that some, and possibly most, adrenal phenylethanolamine-N-methyltransferase may be in a particulate form in intact tissue, and that solubilization artifacts during tissue preparation could account in part for the large proportion of soluble phenylethanolarmine-N-methyltransferase reported previously.
Specific changes in lymphocyte subpopulations: a potential mechanism for stress-induced immunomodulation

The mechanisms by which stressors alter immune function are not well understood. One hypothesis for stress-induced immunomodulation is that since immune responses require cooperation of different cell types, stress-induced shifts in cell populations might affect an organism's ability to mount an immune response. We sought to determine if inescapable shock (IS) could alter lymphocyte subpopulations and if so, whether this could be a mechanism for shock-induced immunomodulation. Our results suggest that IS produces changes in lymphocyte subpopulations and that these shifts could be responsible for modulation of in vivo antibody production. Exposure to IS resulted in an increase in the percent of CD4+ mesenteric lymphocytes and a decrease in the percent of CD8+ mesenteric lymphocytes when examined immediately after the cessation of IS. The stressor reduced antibody production to antigen processed at the altered mesenteric nodes, but did not alter antibody production to antigen processed at other sites. No measurable shifts were found in other compartments examined. The changes in CD44+ and CD8+ mesenteric lymphocytes resulted in an increased CD4+/CD8+ ratio that persisted for 1–24 h after stressor termination, becoming absent 48 h after IS termination. The stress-induced reduction in antibody production occurred only when antigen was given immediately prior to but not when antigen was given 48 h post stress. These findings suggest that the effects of a stressor could be specific to the manner in which the antigen enters the body, and that the stress-induced decrease in antibody production could be due to altered lymphocyte subpopulations as reflected by an increased CD4+/CD8+ ratio.
The effects of crop diversification on herbivorous insects: a meta‐analysis approach

. 1 We used a meta-analysis to evaluate the hypothesis that diversified crops are subject to lower density of herbivorous insects. This method consists of integrating findings of independent studies by calculating the magnitude of treatment effects (effect size). 2 A literature review covering a period of over 10 years yielded twenty-one studies that contained sufficient information for the meta-analysis. The data were analysed according to three criteria: yearly replications of the same study were considered independent data so that research repeated over time would have greater weight; a second meta-analysis was conducted with results of only 1 year because of possible lack of independence between results of the same study; the third approach was to remove studies involving Brassica spp. from the analysis because they are redundant from the standpoint of testing a general hypothesis of crop diversification. 3 The three analyses resulted in effect sizes of 0.50, 0.35 and 0.27, respectively, and all were statistically significant. These results correspond to 69%, 63% and 60% differences between average insect densities for treatment (diversified crops) and control groups. 4 We considered the last criterion for data analysis as the most appropriate because of lowest bias from non-independence between samples. Therefore we concluded that crop diversity caused moderate reduction of herbivorous insect populations. 5 The implications and limitations of meta-analyses are discussed.
Aqueous vasopressin infusion during chemotherapy in patients with diabetes insipidus.

Background. Patients who have suprasellar germinomas in childhood often present with central diabetes insipidus (CDI). The authors investigated the use of aqueous vasopressin (AVP) by continuous infusion to control the fluid and electrolyte balance in germinoma patients with CDI during aggressive fluid hydration as a part of a preirradiation chemotherapy protocol. Methods. Three patients with suprasellar germinomas and CDI were treated with four courses of preirradiation chemotherapy. Two patients were treated with a continuous AVP infusion at an initial rate of 0.08-0.10 mU/kg per hour during hydration. Fluid intake, urine output, body weight, urine specific gravity, and serum electrolyte concentrations were monitored closely, and the infusion rate was adjusted accordingly. Results. Very low dose AVP infusion controlled fluid balance while allowing appropriate diuresis during chemotherapy. Fluid intake and output were markedly less in the AVP-treated patients (3.8 L/m2 per day) than in the untreated patient (20 L/m2 per day). Conclusions. The use of very low dose AVP infusion at an initial rate of 0.08-0.10 mU/kg per hour during hydration therapy allowed easily titratable control of fluid and electrolyte balance in the patients studied and avoided the complications associated with desmopressin acetate antidiuresis or withholding antidiuretic treatment altogether.
Psycho‐educational profile of emotionally disturbed abused children

Abstract This study assessed the cognitive and behavioral deficits of emotionally disturbed abused children. Psychoeducational profiles were contrasted with emotionally disturbed non‐abused children. All of the abused subjects were significantly deficient on five subtests of the ITPA: Auditory Reception, Visual Reception, Verbal Expression, Grammatic and Auditory Closure. Teacher observation indicated qualitative differences between the two groups on both their behavioral and social interaction styles.
Intraoperative blood loss during radical retropubic prostatectomy : Epidural versus general anesthesia

Abstract Objectives There are conflicting reports on the influence of different anesthetic techniques, such as regional versus general anesthesia, on intraoperative blood loss. The purpose of this study was to elucidate the effects of anesthetic technique on intraoperative blood loss in men undergoing radical retropubic prostatectomy (RRP). Methods One hundred patients undergoing RRP for prostate cancer were randomly assigned to receive either epidural anesthesia (EA), combined epidural and general anesthesia (EG), or general anesthesia alone (GA). Intraoperative blood loss was calculated by using a formula that accounted for the volume and hematocrit of the fluid suctioned from the surgical field, blood absorbed on surgical pads, and the patient's hematocrit. Results Mean blood loss in the EA group (1490 ± 90 mL; mean ± SEM) was significantly less than mean blood loss in both the EG group (1810 ± 100 mL) and the GA group (1940 ± 130 mL) (P = 0.01). Blood loss was not different between the EG and the GA groups (P = 0.7). Significantly less blood was transfused during surgery in the EA group (730 ± 50 ml) compared with the EG (960 ± 60 mL) and GA (950 ± 70 mL) groups (P = 0.02). Conclusions Similar blood loss in patients receiving general anesthesia, either alone or when combined with epidural anesthesia, implies that epidural anesthesia did not reduce bleeding, but, rather, that general anesthesia increased blood loss.
Narrow Band Imaging in Barrett’s Esophagus

Barrett's esophagus is the premalignant lesion for esophageal and esophagogastric junction adenocarcinoma. Progression of Barrett's esophagus to dysplasia and cancer can occur, thus requiring endoscopy with random biopsy examinations. Currently, the diagnosis of metaplastic and dysplastic mucosa within the esophagus requires endoscopy with biopsy examination of abnormal-appearing tissue. The presence of intestinal metaplasia and dysplasia within the esophagus often is patchy, and our current practices of performing standard endoscopy with random biopsy examinations are inaccurate. Narrow band imaging is among several tools used in the esophagus to improve detection of Barrett's esophagus and associated dysplasia. Current studies show that these techniques are promising, although the results still are preliminary.
Fiber Optics in X-Ray Diagnostics Applications

This lecture contains several discussions of the way in which fiber optics have found widespread use in diagnostics apaplications. Several lectures in Chapter 2 outline the way in which fiber optics can be used to measure the current and voltage time histories in this difficult environment. The sections by George Chandler and Jim Chang also discuss fiber optics in plasma diagnostics applications. In this lecture, I will describe how fiber optics can be used as active transmitters of diagnostic data and some ways in which they can be used as passive radiation-to-light converters. I will also discuss the problems of radiation damage and temporal dispersion which are encountered in using fiber optics to transmit diagnostic data and some of the techniques used to mitigate these problems.
Direct synthesis of Ru–Ni core-and-shell nanoparticles by spray-pyrolysis: Effects of temperature and precursor constituent ratio

Abstract Core-and-shell nanoparticles of Ru–Ni in the size range of 5–10 nm were synthesized by a single-step spray-pyrolysis process. Ruthenium chloride (RC) and nickel chloride (NC) were dissolved in water and used as a feed stream through an ultrasonic atomizer. The ruthenium chloride to nickel chloride (RC/NC) ratio was varied from 1:1 to 5:1 at various operating temperatures ranging from 500 °C to 1000 °C. Smooth core-and-shell nanoparticles were formed when the RC/NC ratio was 3:1 and 5:1 at 800 °C and 600 °C. A mechanism leading to the formation of such morphologies was proposed and was compared with the experimental results. It was found that as the RC/NC ratio in the precursor increased, temperature can be decreased to obtain core-and-shell nanoparticles. RC/NC ratio of 1:1 at low temperatures of 500 °C generated core-and-shell nanoparticles which are concentric rings. No core-and-shell morphologies were observed at temperatures higher than 800 °C. Once the core-and-shell particles are formed, the temperature can be varied in the range of 200 °C to cause a geometry change from core-and-shell to spherical nanoparticles.
Nonequilibrium and nonadiabatic effects on excited state electron transfer reactions in solution

Abstract Picosecond emission spectroscopy is used to examine the intramolecular charge transfer reaction of N,N-dimethylaminophenyl sulphone in alcohol solution. The effects of nonequilibrium distributions on the reaction surface as well as nonadiabatic effects arising from the time scale of the reactive process and solvent diffusion are discussed. The implications of these data on the motion along the reaction potential energy surface are described.
The labelling of an axonal membrane component with 4-(N-maleimido) benzyltrimethylammonium, a reagent capable of affinity-labelling the α-subunit of the nicotinic acetylcholine receptor

Membrane vesicles, isolated from crustacean axons, were treated, following disulfide reduction, with 3H-NEM or with 3H-MBTA. SDS polyacrylamide gel electrophoresis showed that exposure to NEM (a nonspecific thiol reagent) resulted in the labelling of several peptide bands, while with MBTA only a single band with a molecular weight of 50,000 was labelled. Reaction with MBTA (believed to be a specific label for the nicotinic acetylcholine receptor) could be largely prevented by preincubation with d-tubocurarine or bromacetylcholine.
Voluntary Inter-Cultural Exchange and Understanding Groups: The Roots of Success in U. S. Sister City Programs

Sister City Programs (SCPs) are an important type of inter-cultural exchange program. This paper reports on a largely qualitative evaluation of a purposive sample of U.S. SCPs (108 affiliations) based on observations, content analysis and nearly 2,000 interviews in 21 countries. Often originating because of U.S. immigrants from some non-U.S. country or their descendants, SCPs are usually bi-national volunteer groups with, in principle, Sister City Committees on both sides. Success of SCPs was defined in terms of their being two-sided (reciprocal) and promoting mutual friendship and understanding across cultures through various activities mainly run by a Sister City Committee. Youth exchanges were often success-promoting, especially when carefully organized and lasting a month or so. Exchanges involving families and friends were also often success-promoting if they lasted long enough, involved reciprocal homestays and close relationships, with someone learning the other's language. Not very successful were exchanges of mayors and city officials, which tended to be very formal and impersonal. Similarly unsuccessful were tourist activities (often unreciprocated), which were generally brief and superficial, with hotel stays and minimal contact between visitors and residents. About one-fourth of SCPs with one side in the U.S. seemed dormant or "dead," for a variety or reasons. Another one-half of SCPs engage in some activities but do not reach a high level of people-to-people exchange. The final one-fourth achieve substantial people-to-people exchange. For the latter programs, there is substantial impact on inter-cultural understanding at the level of individuals.
Selectivity of cations and nonelectrolytes for acetylcholine-activated channels in cultured muscle cells.

The selectivity of acetylcholine (A-Ch)-activated channels for alkali cations, organic cations, and nonelectrolytes in cultured muscle cells has been studied. To test the effect of size, charge, and hydrogen-binding capacity of permeant molecules on their permeability, we have obtained the selectivity sequences of alkali cations, compared the permeability of pairs of permeant molecules with similar size and shape but differing in charge, and studied the permeability of amines of different hydrogen bonding capacity. ACh-activated channels transport alkali cations of small hydration radii and high mobility. The molecules with positive charge and (or) a hydrogen-bond donating moiety are more permeable than the ones without. On the other hand, several nonelectrolytes, i.e., ethylene glycol, formamide, and urea, do have a small, but measurable, permeability through the channels. These results are consistent with a model that ACh-activated channel is a water-filled pore containing dipoles or hydrogen bond accepting groups and a negative charged site with a pK of 4.8.
Adatoms and their relation to surface stress

Experimental techniques are now available to measure changes in surface stress due to submonolayer coverages of adatoms on a substrate. It has been observed that even for fairly low coverage, a significant stress develops that can greatly impact growth mechanisms and defect formation during the early stages of crystal growth. In this manuscript, the relationship between adatoms and macroscopic stress is developed within a rigorous continuum framework that has direct links with atomic scale properties of adatoms. The result provides a means for measuring properties of individual adatoms and gives new insight to adatom interactions. Comparison with experiments shows that adatom interactions depend on strain. A strong strain dependence is evident, even when adatoms are far apart. It is found that the dipole characterizing an adatom may change with applied strain, strain induced by other defects, and interactions with boundaries. The analysis yields a simple relation between surface stress and the level of adatom coverage during deposition that is in agreement with experimental observations.
Ritodrine Hydrochloride in the Control of Premature Labor Implications for Use

Ritodrine hydrochloride is the only pharmacologic agent approved by the FDA for use in control and prevention of premature labor. The physiologic effects of ritodrine hydrochloride are reviewed and some practical guidelines for its administration are discussed.
Materials flow analysis and dynamic life-cycle assessment of lightweight automotive materials in the U.S. passenger vehicle fleet

PASSENGER vehicles in the U.S. are responsible for nearly 70% of the nation's liquid fuel use, and 18% of greenhouse gas (GHG) emissions. These impact figures are increasing and motivate policy efforts to curb them, such as defining higher vehicle fuel economy standards.
Reduction of Poisson manifolds

Reduction in the category of Poisson manifolds is defined and some basic properties are derived. The context is chosen to include the usual theorems on reduction of symplectic manifolds, as well as results such as the Dirac bracket and the reduction to the Lie-Poisson bracket.
Relationships between ganglion cell dendritic structure and retinal topography in the cat.

The morphology of ganglion cell dendritic trees varies across the cat retina. Evidence is presented that the variation in two attributes of ganglion cell dendritic structure can be accounted for by specific aspects of the topography of the adult and developing retina. The first attribute considered was the displacement of the center of the dendritic field from the cell body in the plane of the retina. The results of this study provide evidence that most ganglion cell dendritic fields are displaced away from neighboring cells, i.e., down the retinal ganglion cell density gradient. Because of the systematic dendritic displacement locally, the centers of the dendritic fields are arranged in a more precise mosaic than are their cell bodies. The second attribute considered was the elongation and orientation of the dendritic fields. From approximately embryonic day 50 to postnatal day 10 the cat retina undergoes a process of maturation (reviewed by Rapaport and Stone: Neuroscience 11:289–301, '84) that begins at the area centralis and spreads over the retina in a horizontally elongated wave. We found that the elongation and orientation of retinal ganglion cell dendritic fields is significantly correlated with the shape of the wave of maturation. The orientation of a dendritic field is not predicted by the direction of its displacement nor is it directly related to the distribution of neighboring retinal ganglion cells. These results indicate that the displacement of a ganglion cell's dendritic field from its cell body results from mechanisms different from those responsible for the orientation of the dendritic field. Factors that may be responsible for these two attributes of ganglion cell dendritic morphology are discussed.
Intraoperative optical coherence tomography using the RESCAN 700: preliminary results from the DISCOVER study

Significant integrative advances are needed for intraoperative optical coherence tomography (iOCT) to achieve widespread use across ophthalmic surgery. A surgeon feedback system that provides microscope integration, heads-up display and foot pedal control of the OCT scan location represents a major interval advance in ophthalmic surgery. In this report, we describe the preliminary findings of the Determination of feasibility of Intraoperative Spectral domain microscope Combined/integrated OCT Visualisation during En face Retinal and ophthalmic surgery (DISCOVER) study, a multisurgeon investigational device study examining the role of microscope integrated iOCT systems with surgeon heads-up display feedback (eg, Carl Zeiss Meditec RESCAN 700, Cole Eye Institute iOCT prototype). During surgical manoeuvres in anterior segment and posterior segment surgery, this technology provides rapid visualisation of the area of interest and provides the surgeon with information regarding instrument-tissue interactions. This system represents a major advance in iterative technology for iOCT and may provide the first widely available platform for surgeons to seamlessly assimilate this technology into the operating room theatre.
Low-threshold 840-nm laterally oxidized vertical-cavity lasers using AlInGaAs-AlGaAs strained active layers

We explore the use of a novel strained AlInGaAs-AlGaAs material system to achieve low-threshold current in oxide-apertured vertical-cavity lasers (VCLs) emitting near 850 nm. We report a low continuous-wave (CW) room-temperature threshold current of 290 /spl mu/A from top-emitting, 840-nm VCLs with a 5-/spl mu/m-wide thin-oxide aperture. The low-threshold current has been attributed to the use of strained active layers, which increase the gain and reduce the transparency current. We also studied the effects of post-growth rapid thermal annealing (RTA) on the characteristics of AlInGaAs-AlGaAs VCLs and found that RTA improves the material quality and significantly enhances VCL performance.
PHOSPHORUS: a task-based agent matchmaker

PHOSPHORUS is an agent matchmaking service that exploits domain ontologies, description logic, and a highly declarative language to reason about task-related agent capabilities. PHOSPHORUS uses the EXPECT goal language to represent the tasks that agents are capable of accomplishing, as well as requests to locate agents with a required capability. PHOSPHORUS supports matching through subsumption, reverse subsumption, and several kinds of goal reformulation.
Metabolic response of Platynota stultana pupae during and after extended exposure to elevated CO2 and reduced O2 atmospheres

The metabolic response of Platynota stultana pupae to elevated CO2 and reduced O2 atmospheres was measured using microcalorimetry. Initial measurements at 20°C immediately upon placement in controlled atmosphere indicated a decrease in metabolic heat rate (MHR) of 27, 45, 56, 56, and 72% in an atmosphere of 5, 10, 20, 40, and 79% CO2, respectively, and a decrease of 20, 50, 66 and 100% under 6, 2, 1, and 0% O2. With extended exposure to controlled atmospheres, MHR increased under 5, 10, and 20% CO2 and 6 and 2% O2; however, the increase was greater and occurred more rapidly with lower CO2 and higher O2 concentration. The MHR at 40 and 79% CO2 remained at the initial reduced level for 8 and 6 days, respectively, then decreased with longer exposure. The MHR of pupae held under 1 and 0% O2 remained at the initial reduced level for 22 days. Upon transfer to air, the MHR of pupae increased from the reduced levels and then decreased. When the MHR decreased by no more than 30%, as a result of controlled atmosphere treatment, the pupae still developed into adults. However, when the MHR decreased by more than 50%, the energy supply was insufficient and the pupae died. Pupa mortality was comparable between 5% CO2 and 6% O2, and 10% CO2 and 2% O2. The MHR was reduced less under 20% CO2 than under 2 or 1% O2; however, the pupae were more susceptible to 20% CO2 than 2 or 1% O2. These and other data indicate an increased toxicity of high CO2 over low O2 atmospheres that may be related to an increase in membrane permeability as a result of CO2 treatment.
Assessing temporal integration spans in ADHD through apparent motion.

Objective We use psychophysical methods to examine the maximum time intervals over which discrete events can be temporally integrated into the percept known as apparent motion. We hypothesized that the maximum time interval would be shorter in participants with attention deficit hyperactivity disorder (ADHD) than it would be in a control group. Method Thirty-five adults with ADHD and 40 adult controls without ADHD participated in an apparent motion task, in which they viewed a stimulus flashing in 2 different locations and were asked to complete the trajectory of motion that they perceived. The stimulus flashes were separated by varied temporal intervals ranging from 200 to 2300 ms. Clear trajectory perception in this task indicates successful temporal integration. Results At short intervals, we found evidence of clear trajectory perception in both groups, indicated by low variability in path estimations. At the longest intervals, neither group demonstrated path perception, evidenced by high variability in estimations. However, at intermediate intervals (1.7 s), the control group demonstrated path perception while the group with ADHD did not, indicating a difference between the 2 groups in the maximum interval over which apparent motion could be perceived. Conclusions We suggest that ADHD is generally characterized by a contraction in the time scale governing the rate at which association strength decays. In contrast to theories that postulate general time-processing deficits, this work provides a precise sense in which temporality is disturbed in ADHD.
A Simulation of the Humoral Immune System

The idea of theoretically describing the immune system has become popular in the past decade, and in fact the existence of the present volume is evidence for the emergence of the field. With the advent of modern high-speed computers it no longer seems impossible to model and simulate the behavior of the immune system. Previous attempts at modeling the immune system have generally followed the course of focussing on a phenomenon or class of phenomena, writing down the differential equations for these phenomena and then trying to obtain solutions (Perelson 1988, 1990). This approach has led to better understanding of the phenomena and how they might be applied to the immune system, but often the mathematical approximations required to obtain solutions have removed much of the connection with the actual biological system, or at least made the connections much more opaque.
Motility Characteristics Are Altered for Rickettsia bellii Transformed To Overexpress a Heterologous rickA Gene

The rickettsial protein RickA activates host cell factors associated with the eukaryotic actin cytoskeleton and is likely involved with rickettsial host cell binding and infection and the actin-based motility of spotted fever group rickettsiae. The rickA gene sequence and protein vary substantially between Rickettsia species, as do observed motility-associated phenotypes. To help elucidate the function of RickA and determine the effects of species-specific RickA variations, we compared extracellular binding, intracellular motility, and intercellular spread phenotypes of three Rickettsia bellii variants. These included two shuttle vector-transformed R. bellii strains and the wild-type isolate from which they were derived, R. bellii RML 369C. Both plasmid shuttle vectors carried spectinomycin resistance and a GFPuv reporter; one contained Rickettsia monacensis-derived rickA, and the other lacked the rickA gene. Rickettsia bellii transformed to express R. monacensis rickA highly overexpressed this transcript in comparison to its native rickA. These rickettsiae also moved at higher velocities and followed a more curved path than the negative-control transformants. A lower proportion of R. monacensis rickA-expressing bacteria ever became motile, however, and they formed smaller plaques.
From the lab to the dorm room: metacognitive awareness and use of spaced study

Laboratory studies have demonstrated the long-term memory benefits of studying material in multiple distributed sessions as opposed to one massed session, given an identical amount of overall study time (i.e., the spacing effect). The current study goes beyond the laboratory to investigate whether undergraduates know about the advantage of spaced study, to what extent they use it in their own studying, and what factors might influence its utilization. Results from a web-based survey indicated that participants (n = 285) were aware of the benefits of spaced study and would use a higher level of spacing under ideal compared to realistic circumstances. However, self-reported use of spacing was intermediate, similar to massing and several other study strategies, and ranked well below commonly used strategies such as rereading notes. Several factors were endorsed as important in the decision to distribute study time, including the perceived difficulty of an upcoming exam, the amount of material to learn, how heavily an exam is weighed in the course grade, and the value of the material. Further, level of metacognitive self-regulation and use of elaboration strategies were associated with higher rates of spaced study. Additional research is needed to examine student study habits in a naturalistic setting, and to explore effective ways to encourage behavior change through motivational and teaching techniques.
A note on lateral variation in upper mantle shear‐wave velocity across the Alpine front

Summary. We have detected what appear to be strong lateral variations in upper mantle shear-wave velocities under Europe and western Eurasia. The evidence suggests that the Alpine belt of southern Europe is underlain by a tectonic upper mantle, with a thin lid and thick low-velocity layer whereas the eastern Europe-western Russia Precambrian platform is underlain by shield-like upper mantle. The transition zone between the two appears to be sharply defined and coincident with the northern boundary of the Alpine belt. The techniques used in the analysis include the construction of synthetic seismograms for long-period S- and SS-waves in the distance range 30"-60", where differences in upper mantle shear-wave velocity most strongly affect the differential times (SS-S) and the ratio of SS to S amplitudes as a function of epicentral distance. A comparison with upper mantle shear-wave structure in western North America as reported by Grand & Helmberger indicated that under the Alpine belt the upper mantle is considerably faster than under western North America, a situation that may be interpreted as due to the much larger and widespread thermal anomalies under western North America as a consequence of the existence ofa subducted ridge.
Beamspace DOA estimation featuring multirate eigenvector processing

A novel approach to angle of arrival estimation in beamspace for a uniform linear array is presented. Beamspace noise eigenvectors may be telescoped to vectors in the element-space noise subspace. The telescoped noise eigenvectors are bandpass, facilitating multirate processing involving modulation to baseband, filtering, and decimation. As these operations are linear, a matrix transformation applied to the eigenvectors may be constructed a priori. Incorporation of the technique into either the Root-MUSIC or ESPRIT prescriptions provides a computationally efficient procedure. Compared to past efforts to adapt Root-MUSIC and ESPRIT to beamspace, this approach circumvents the need for restrictive requirements on the form of the beamforming transformation. An asymptotic theoretical performance analysis is also included to provide an alternative to computationally intensive Monte Carlo simulations. Simulation studies show the validity of the performance predictive expressions and verify that the procedure, when incorporated into the Root-MUSIC/ESPRIT formulations, produces a direction finding technique that nearly attains the Cramer-Rao bound (CRB).
Changes in axonally transported proteins in the rat visual system following systemic methyl mercury exposure.

: In an effort to understand the effect of methylmercury on protein synthesis and axonal transport, we have analysed the composition and rate of axonally transported proteins in the retinal ganglion cells of the mature rat. By means of scintillation spectrometry and autoradiography, it was established that systemic exposure to 4 mgHg/kg/day for four to six days, or twelve days, resulted in an increased rate and volume of transported protein-bound radioactivity in the visual system of the mature rat. In an effort to characterize these changes, the composition of transported polypeptides was analysed by means of SDS polyacrylamide gel electrophoresis. Selective changes in the composition of transported polypeptides were evident. These changes of a small subset of proteins known as GAPs (growth-associated proteins) are consistent with the suggestion that they may have been involved in growth-specific functions during the early stages of methyl mercury exposure. We concluded that, during this period, retinal ganglion cells may express growth-related genes and engage in regenerative processes.
Effects of juvenile hormone on eggs and adults of the cat flea (Siphonaptera: Pulicidae).

Juvenile hormone III plays a major role in regulating feeding and reproduction in the adult cat flea, Ctenocephalides felis (Bouche ´). Both blood consumption and egg production increased in a dose-dependent manner up to a maximum at 1,250 ppm when fleas were continuously exposed to concentrations up to 12,500 ppm juvenile hormone. Histological studies demonstrated that juvenile hormone III also stimulated cellular differentiation of salivary gland epithelia, midgut epithelia, and fat body cells, enhancing the ability of the adult flea to digest blood and synthesize vitellogenins for the maturing oocytes. In unfed fleas, exposure of adults to concentrations of $1,000 ppm juvenile hormone III applied to filter paper resulted in membrane lysis and destruction of salivary gland and midgut epithelial cells, fat body cells, and ovarian tissue. Unlike juvenile hormone mimics, which have potent ovicidal effects in fleas, juvenile hormone had little effect in preventing egg hatch; 58% of the eggs laid by fleas treated with 12,500 ppm juvenile hormone III hatched, and a concentration of 30,000 ppm was required to reduce hatch to 2% in untreated eggs exposed to treated filter paper for 2 h. Compared with the juvenile homone mimic pyriproxyfen, juvenile hormone III was less toxic to fed adult fleas. However, at a concentration of 12,500 ppm, juvenile hormone killed '45% of the adults and caused autolysis and yolk resorption in the developing oocytes. Thus, at high concentrations, juvenile hormone appears to have a pharmacological effect on fleas, which is highly unusual in insects.
401(k)-Type Plans and Individual Retirement Accounts (IRAs)

Individual account retirement plans, such as 401(k) plans and individual retirement accounts (IRAs), have continued to increase their share of retirement assets (currently totaling about $7.5 trillion in assets), and this share is projected to grow further, particularly for private-sector workers. Consequently, tracking how many individuals have these plans and how much has been accumulated in them is an important indicator of how workers are preparing for retirement financially. This paper uses the most recent data from the Survey of Income and Program Participation (SIPP), conducted by the U.S. Census Bureau, to examine the prevalence of these accounts among workers ages 21-64. The paper begins with an examination of the ownership of IRAs and participation in 401(k)-type plans (singularly and in combination) among workers ages 21-64. Next, it investigates the average contribution, the percentage of participants contributing the maximum amount, and the average earnings in 401(k)-type plans and IRAs. Finally, it presents the latest official government data on the assets and participants, where they are available for these accounts.
The Importance of Exploration in Online Marketplaces

In online marketplaces, a critical objective of the platform's intermediation is ensuring the sellers' quality. This is particularly challenging in large marketplaces, where it's infeasible to pre-screen all sellers, and the platform uses feedback from previous transactions to infer the sellers' quality. However, this process matches existing buyers to new, untrusted sellers, potentially leading to a poor buyer experience. This raises a natural exploration-exploitation tradeoff in online marketplaces. Here, the authors suggest that the exploration-exploitation tradeoff is closely linked to the nature of externalities in the marketplace. Using a stylized model, they uncover a qualitative difference between exploration and exploitation, based on the underlying network externalities between buyers and sellers in the market. In particular, in many settings, they show that by focusing on exploration, the platform can achieve a higher overall rate of successful matches.
Who Walks the Watchdog? Bureaucratic Oversight and the Governement Accountability Office

Created in 1921 and strengthened after Watergate, the Government Accountability Office (GAO) is Congress's primary watchdog agency over the administrative state. The GAO investigates, culls, and synthesizes stances on a multitude of policy programs and expenditures on its own initiative, by legislative mandate, and at the request of congressional committees and individual members of Congress. This paper examines how members of Congress use the GAO to advance their own policy preferences and how the GAO makes strategic auditing decisions on its own. From a simple model supplemented by interviews of GAO officials, I generate several testable empirical propositions. First, in periods of divided government, members and committee chairs should request more GAO investigations; in periods of united government, members of the minority party should request more GAO studies. Second, members of Congress may use the GAO to increase their chances of being reelected. In particular, Senators facing reelection sooner should request more studies than Senators facing reelection in a later cycle. Third, if the GAO is concerned about how it is perceived by its sponsors in Congress, it should make fewer recommendations when its work is not congressionally requested. I test these propositions using information from the GAO Documents Database, which I constructed from details on all published GAO reports and testimony to Congress, for 1986-1997. I find some support for the institutional theory of how Congress uses the GAO. House committee chairpersons are more likely to request a GAO investigation when there is divided government. A change from united to divided government corresponds to a 5.68 percent increase in the probability that a House committee chairperson will join a request. House committee ranking minority members are less likely to turn to the GAO when there is divided government. A shift from united to divided government leads to a 2.16 percent decrease in the probability that a House committee ranking minority member will sign onto a request. It also appears that Senators facing the voters in the next election request more studies than other Senators. Finally, the GAO seems to issue recommendations carefully. It makes more recommendations to Congress when a study is requested but makes more recommendations to agencies when a study is self-initiated, perhaps anticipating that Congress will call for agency changes when an investigation is requested.
Health Care Access, Utilization, and Management in Adult Chinese, Koreans, and Vietnamese with Cardiovascular Disease and Hypertension.

Asians are often pooled together when evaluating disparities in health care indicators (access, utilization, and management), though substantial variation may exist across different Asian ethnicities. The aim of this study was to compare health care indicators among Chinese, Korean, Vietnamese, and non-Hispanic white (NHW) adults with cardiovascular disease and hypertension (CVD/HTN). We analyzed health care indicators using multivariable logistic regression in a sample of Asians and NHWs with CVD/HTN from the 2011–2012 California Health Interview Survey (CHIS). Koreans had the lowest utilization of emergency room (ER) or inpatient hospital services; Vietnamese had the lowest access to a personal doctor; Chinese had the lowest adjusted odds of having seen a doctor in the prior 12 months; and all Asians received fewer written heart disease care plans compared to NHWs. Even when utilization of ER for heart disease appeared to be similar, lack of access to a doctor was a more common reason noted by Asians versus NHWs. However, a lower proportion of Asians reported delays in receiving prescription or care. Accounting for differences across groups did not diminish these disparities. Health care indicators varied by race and across Asian ethnicities even after controlling for sociodemographic factors, insurance coverage, and health status. Future studies should consider oversampling other Asian ethnicities and assessing more in depth the potential impact of ethnicity-related factors on disparities in health care indicators.
“The Road Less Traveled”: Combining Disability Studies and Quantitative Analysis with Medium and Large Data Sets:

Historically, researchers focused on individuals with severe disabilities have utilized single-subject research methodologies to study the application of the behavioral theory to learning. In contr...
A Dual-Band Millimeter-Wave Direct-Conversion Transmitter With Quadrature Error Correction

The analysis and implementation of a dual-band direct-conversion millimeter-wave transmitter is presented. The proposed dual-band modulator uses high-impedance loads at two frequencies for the local oscillator driving amplifiers and power amplifier (PA) pre-amplifiers. To correct the amplitude and phase imbalance of the in-phase and quadrature channels at Q- and W-bands, the paper suggests a digitally controlled quadrature error correction stage to finely calibrate these errors and lower the error vector magnitude (EVM) without increasing the baseband digital-to-analog converter resolution. The transmitter is fabricated in 0.12- μm silicon-germanium BiCMOS process and occupies an area of 5.5 mm 2 . At 45-GHz carrier frequency, error correction improves the sideband suppression ratio (SSR) by 10 dB at 2.4-MHz IF frequency. The EVM is lowered from 3.21% to 2.38% for a 64-QAM constellation at a 2.4-Ms/s symbol rate. At 94-GHz carrier frequency, the SSR is improved from 24 to 41 dBc at 2.4-MHz IF frequency, and the EVM is lowered by more than 1% for a 16-QAM constellation at 3-Ms/s symbol rate. A dual-band PA breakout measurement indicates the peak power-added efficiency of 15% with 14-dBm maximum saturated power (Psat) at 43 GHz and 9-dBm Psat at 82 GHz is achieved.
Finding Choice Alternatives in Memory: Probability Models of Brand Name Recall:

Recalling brand names is an important aspect of consumer choice in many situations. The authors develop a general Markov model that relates probabilistic aspects of recall to consumer and marketing...
Current Issues in Analytical Description of Particle/Droplet-Laden Turbulent Flows

The particle/droplet-laden turbulent flows occur in many important natural and technological situations, e.g., cloud [1], aerosol transport and deposition [2], spray combustion [3, 4], fluidized bed combustion [5], plasma spray coating and synthesis of nanoparticles [6]. Undoubtedly, turbulence itself remains as a difficult and unsolved problem of classical mechanics despite many persistent efforts by physicists and engineers. The presence of particles/droplets (hereafter simply referred to as particles) further adds to the complexity of the turbulence. The particle behavior in turbulent flows gives rise to many interesting phenomena, such as, turbophoresis [7], turbulent thermal diffusion and barodiffusion [8, 9], preferential distribution, and anomaly and intermittency [9, 10]. It is challenging to come up with a unique predictive theory for the particle phase which is useful for engineering purposes and also capable in quantifying various related phenomena.Copyright © 2003 by ASME
UNIVERSAL CULTS AND INTRA-DIFFUSION: IGBO IKENGA IN CULTURAL RETROSPECTION

The purpose of this investigation is to examine the problem of diffusion of Ikenga art form in geographically contiguous cultures. Although the concept of diffusion of cultural traits among contiguous cultures is well established among certain kinds of anthropologists, fresh theories of interpretation may be observed. First, I will try to develop the framework which would help to identify the strategic factors in the process of diffusion and facilitate the ordering of what is currently known about them. Second, since the establishment of a framework seldom includes anything but a model, Igbo Ikenga is focused upon to illustrate how deduction from art may lead to new factual conclusions. Current anthropological concern about the diffusion of elements of culture in the Niger/Benue basin has attracted attention to the Ikenga art form because of the apparent widespread occurrence of the Ikenga cults among the Igbo, Benin, and Igala. Jeffreys (1954 pp. 25-40) traces the origin of the word “ Ikenga ,” and thus its cult, to the Kengawa (Hausa) people of Sokoto Province. Later, William Fagg (1960, “The Ibo Tribes”) explains the “universal cults of Ikenga ” partly in terms of adaptability among contiguous ethnic groups, particularly as certain Igbo culture traits show similarity to those of their neighbours at the periphery. More recently, this notion of an “intra-diffusion” has been extended by Bradbury. Comparing diffusion processes between the Igbo and Benin Ikenga cults, Bradbury (1961, p. 138) attributes a greater possibility to one single Ikenga cult which later separated into the Igbo and Benin and mutually coexisted.
Leading-edge vortex behavior in the vicinity of delta wing apex

An experimental investigation has been conducted regarding the structure of the flow field in the vicinity of the apex of a 65-deg delta wing. Data taken during this experiment show that the windward leading-edge vortex burst point intersected the apex at low to moderate body-axis roll angles only when the wing's longitudinal axis was inclined sufficiently high. As the roll angle was increased further, the flow over the windward half of the apex becomes fully separated. However, further increases in the roll angle brought about a reformation of the primary leading-edge vortex. These flows are shown to be dependent on the local geometric orientation and configuration of the wing leading edge, and are significantly less dependent on the overall wing geometry. (Author)