cssi/SciSciGPT-SciSciNet huggingface dataset:
Evaluation of collision and stirring rates in circumplanetary particle disks based on three-body orbital integrations

Abstract We study collision and velocity stirring rates of particles in a circumplanetary disk with low optical depth where the epicyclic approximations can be applied to particle motions. We use orbital integrations in the three-body problem where both direct collisions and gravitational encounters between particles are taken into account. Using these numerical results together with the previously derived analytic results for nongravitating particles (Ohtsuki, 1999. Icarus 137, 152–177), we examine the dependence of collision and stirring rates on eccentricities and inclinations in the case of gravitating particles to calculate the averaged rates for a Rayleigh distribution of particles’ eccentricities and inclinations. Numerical results show that the dynamical friction rates for nongravitating ring particles can approximate the numerical results of three-body orbital integrations fairly well for a wide range of parameters. However, the effects of self-gravity substantially changes the collision and viscous stirring rates in low velocity cases. On the basis of the numerical results of orbital integrations in such low velocity cases and the analytic results for nongravitating cases, we derive semi-analytic formulae for collision and stirring rates for gravitating particles which can be used for the entire range of velocities. We calculate the evolution of root mean square eccentricities and inclinations of ring particles using these formulae, and find excellent agreement with the results obtained by N-body simulations.
Synthesis, bulk characterization, and surface characterization of p-hydroxystyrene/styrene copolymers

Styrene/p-hydroxystyrene copolymers were prepared from copolymers of styrene and p-benzyloxystyrene by cleavage of the ether bond. Nuclear magnetic resonance spectroscopy was used to characterize the polymers before and after the ether cleavage reaction. Reactivity ratios were calculated by applying the method of least squares to data generated from the Fineman–Ross equation (r1 = 0.37, r2 = 0.28). The surface chemistry of centrifugally cast films of the homopolymers and the copolymers was studied by using electron spectroscopy for chemical analysis (ESCA). The Zisman contact angle method was used to determine the critical surface tension in air for each polymeric surface. Water contents of hydrated films were determined gravimetrically. The polar character of the surface was shown to increase to a small degree with an increase in the p-hydroxystyrene component. Polymers with high p-hydroxystyrene contents did not exhibit pronounced hydrogel character.
Cardiac Asthma: Transforming Growth Factor-β From the Failing Heart Leads to Squamous Metaplasia in Human Airway Cells and in the Murine Lung

Background Cardiac asthma describes symptoms of airflow obstruction due to heart failure. Chronic heart failure is associated with decreased FEV 1 , and FEV 1 improves after heart transplantation. Fibrotic remodeling of the heart and airways is mediated, in part, through transforming growth factor (TGF)-β. Blood TGF-β 1 concentration correlates with ventricular remodeling in cardiac disease, and TGF-β decreases after repair. Methods We established a coculture of normal human bronchial epithelial (NHBE) cells differentiated at air-liquid interface with submerged basal cardiomyoblasts. Airway cells were immunostained with cytokeratin, actin, and involucrin. TGF-β synthesis was assayed using enzyme-linked immunosorbent assay. Phosphorylation of Smad in NHBE cells was determined by Western blotting. Mice given doxorubicin developed cardiac failure, and their airways were histologically examined. Results Coculture induced involucrin-positive squamous metaplasia of NHBE cells, and this was attenuated by TGF-β antibody. Total TGF-β 1 was increased in coculture conditioned medium ( P 1 , there was squamous transformation of NHBE cells. One week after removing cardiomyoblasts from culture, squamous metaplasia resolved into normal ciliated epithelia. Smad was phosphorylated in NHBE cells with cardiomyoblasts or with recombinant TGF-β 1 exposure. The airways of mice with heart failure also demonstrated involucrin-positive squamous transformation. Conclusions TGF-β from cardiomyoblasts or from the failing heart can cause airway squamous metaplasia via Smad signaling, and this is blocked by anti-TGF-β antibody and reversed when cardiac cells are removed from culture. This appears to be an important mechanism for airflow obstruction with heart failure, sometimes described as cardiac asthma.
Teaching practices to save America's schools: The legacy of B. F. Skinner

The research and practices found in behavior analysis and the behavioral models of instruction suggest a common set of effective teaching practices. Implementation of these practices could save our schools. They have implications for the students, parents, teachers, and supervisors in our schools. They are presented herein as standards for effective pedagogy and schooling from the viewpoints of students, parents, teachers, and supervisors. Indeed, they may be the necessary ingredients for adequate schooling. All of these practices are feasible now, and all of the parties involved in schooling stand to benefit from their implementation!
Structure and optical properties of MgxZn1−xO nanoparticles prepared by sol–gel method

Abstract Mg x Zn 1− x O particles were synthesized by the sol–gel technique using acetate of zinc and magnesium in a homogeneous aqueous reaction medium. XRD showed that the particles possessed a polycrystalline hexagonal wurtzite structure. The transmission spectroscopes of ZnO, Mg x Zn 1− x O and the mixture of ZnO with MgO were investigated. It was found that the band gap of zinc oxide was increased from 3.32 to 3.65 eV by doping 15% magnesium oxide. TEM picture revealed that Mg x Zn 1− x O particle was about 30 nm with a narrow size distribution. The conductivity and the dielectric properties of the powders have also been improved by Mg doping.
A flexible approach to modelling enrollment choice behavior

Abstract Some researchers who have used the multinomial logit model to analyze enrollment choice behavior have mentioned the independence of irrelevant alternatives (IIA) property as a limitation of that approach. In this paper we use samples from the High School and Beyond data base to estimate both standard multinomial and nested multinomial logit models of enrollment choice behavior. The empirical results indicated that the IIA property was not consistent with choice behavior in our data sample.
Fractal analysis of polymeric and particulate titania aerogels by adsorption

Polymeric and particulate titania (TiO2) aerogels with high surface areas were prepared from sol−gel derived TiO2 lyogels via freeze-drying as well as CO2 supercritical drying. The surface fractal dimensions of these aerogels were evaluated with two methods based on physisorption, one by Avnir and Pfeifer, and the other, the modified form of the Frenkel−Halsey−Hill (FHH) equation. The two approaches yielded almost identical results. The surface fractal dimensions measured are approximately 2.7 and 2.8 for polymeric and particulate TiO2 aerogels, respectively, thereby indicating that the fractal surfaces of particulate aerogels are slightly more irregular than those of polymeric aerogels.
Scanning microscopy of collagen in the basement lamella of normal and regenerating frog tadpoles.

The arrangement of collagen fibers over the body surface in the basement lamella of Pseudaeris and Xenopus tadpoles is described. It can be viewed by scanning microscopy after removal of epidermis and basal lamina by trypsin treatment of alcohol fixed tissue. The orthogonal array is modified in regions where fiber direction changes extensively such as the base of the ventral fin or the posterior part of the head. In these regions "exceptional points" in the orthogonal pattern occur, as described by Rosin (1946). The pattern is bilaterally symmetrical. In the region of the nasal opening the orthogonal pattern is replaced by a mat of randomly oriented fibers. In tail regeneration the wound area is marked by aberrant disposition of collagen anteriorly then a mat of randomly disposed fibers followed posteriorly with a sharp transition to the orthogonal pattern of the regenerate. No fiber terminations could be seen in normal or regenerating regions of the lamella.
Triple-deck structure

Abstract The asymptotic foundation of two-dimensional steady triple-deck theory is reviewed. The total flow is assumed to be the sum of a basic-flow component Q ( x , y ) governed by the boundary-layer equations and a disturbance component q ( x , y ), resulting from a sudden streamwise change (localized disturbance), such as that caused by a hump or dip, a suction or blowing discontinuity, a heating or cooling discontinuity, a trailing edge etc. Substituting the total flow Q + q into the steady two-dimensional Navier-Stokes equations and subtracting the basic-flow quantitites yields nonlinear equations describing the disturbance quantities q . The disturbance quantities are assumed to vary with the streamwise scale X = ( x − 1)Re α , where x = x ∗ ¦x r ∗ , x r ∗ is the center of the localized disturbance, Re = U ∞ ∗ x r ∗ /v , U ∞ ∗ is the freestream velocity and v is the kinematic viscosity of the fluid. Introducing the stretching transformation Y = y Re β , β > 0, and scaling ψ as ψ = ψ Re − χ , where ψ is the streamfunction of the disturbance, we find that there are three distinguished limits when 0 1 2 and hence three sets of least degenerate problems, resulting in a triple-deck structure. These limits correspond to β = α, β = 1 2 and β = 1 2 + 1 3 α . Matching the pressure in these decks demands that α = 3 8 and leads to the triple-deck structure. The upper- and middle-deck problems are linear, whereas the lower-deck problem is linear when χ > 3 4 and nonlinear when χ ⩽ 3 4 . When α = 1 2 , there are two distinguished limits corresponding to β = 1 2 and 2 3 . The upper-deck problem is linear, whereas the lower-deck problem is linear when χ > 5 6 and nonlinear when χ ⩽ 5 6 . The theory is self-consistent and does not depend on the problem being investigated. Application of these theories to the linear three-dimensional compressible stability of two-dimensional compressible boundary layers is described and limitations of the triple-deck theory are discussed.
Prospective and Cross-Sectional Study of Radial Bone Loss in Post-Menopausal Women

The development of the photon absorption technique has provided a precise and accurate method for measuring bone mineral mass in the appendicular skeleton (1). This technique has been utilized to study changes in bone mass in the radius. Scans were performed at midshaft and distal sites as previously reported (2, 3, 5). The measurement is reported as bone mineral content (BMC) in units of g/cm.
Sclerochorioretinal resection for choroidal melanoma. A clinicopathologic correlation of a postmortem eye.

Abstract A 51-year-old patient underwent a technically successful sclerochorioretinal resection with scleral graft for a medium-sized choroidal melanoma, which proved to be of mixed cell type. Though there was complete resection of the tumor and a favorable visual result, the patient developed metastatic melanoma and died 42 months after the original diagnosis and 34 months after the surgical procedure. Postmortem examination of the involved eye demonstrated excellent anatomic preservation of intraocular structures. Of particular interest was the lack of ischemic necrosis in the anterior segment in spite of surgical disinsertion of two rectus muscles and the ablation of the medial long ciliary artery.
Microwave oscillations in parallel Josephson junctions

Abstract It was found that when two Josephson junctions were connected in parallel, constant voltage-current steps appeared in the V-I characteristics for currents above the sum of the zero-field critical currents of the two junctions. These steps only occurred when the critical currents of the two junctions were different. The current steps were separated by voltages which corresponded fairly closely with the fundamental and 2nd and 6th harmonics of fundamental frequency determined by the length of the superconducting strips which connected the two junctions. When junctions which had the same critical currents were connected in parallel no such steps were observed. An analysis, based on the equations derived by Ivanchenko and Stewart is also presented.
Reactivity space analysis of PWR core depletion

Abstract Reactivity space analysis of PWR core depletion is used to investigate solutions to the core burnup and fuel utilization maximization problems. Results of few-region analysis of the SEQUOYAH PWR with the EPRI nodal code simulate-e show that there is an order of magnitude difference in the effect of fuel arrangement and reactivity control in the optimal solutions. It is concluded that emphasis in the core reload design should be given to achieving the optimal fuel arrangement. Furthermore, it is shown that the constant power, Haling depletion strategy is an effective method of isolating the arrangement problem from reactivity control considerations during the core design process.
Colorectal cancer in ulcerative colitis patients: survival curves and surveillance.

BACKGROUND Survival curves can provide useful information for designing cancer surveillance programs. OBJECTIVE To outline how to derive the density and hazard functions from the survival curve and to use this information to make recommendations regarding cancer surveillance in patients with ulcerative colitis. DISCUSSION The hazard of cancer or dysplasia remains low during the first decade of ulcerative colitis but rises exponentially thereafter. After 40 years, approximately 20% of patients with ulcerative colitis acquire cancer or dysplasia per year. CONCLUSION A reasonable recommendation for cancer surveillance based on information from survival curves would be a colonoscopy with biopsy approximately 10 years after the onset of ulcerative colitis, and repeated every 3 years for the next decade, every 2 years for the subsequent decade, and every year thereafter. Prophylactic proctocolectomy is an option after 40 years of disease due to the extremely high cancer risk, but data supporting this option are sparse.
Analysis of implicit transmit null-forming and channel reciprocity

An implicit transmit null-forming scheme is considered, which forms a null toward its neighbouring station based on the channel information it acquires by overhearing the neighbouring station's transmissions. Although channel reciprocity is generally required for an implicit approach, it is proved that channel reciprocity is not required for the implicit transmit null-forming scheme.
Comparison of Socio-Demographic Characteristics of a Computer Based Breastfeeding Educational Intervention Among Rural Hispanic Women

Examine association between socio-demographic characteristics and breastfeeding knowledge, self-efficacy and breastfeeding attrition prediction among rural Hispanic women. 46 rural Hispanic women, aged 18–38 years were enrolled from Regional West Medical Center, Scottsbluff, Nebraska. Intervention (n = 23) and attention control groups (n = 23) received bi-lingual breastfeeding education using touch screen computer and printed educational material. Participants were enrolled during last 6 weeks of pregnancy. Follow up assessments were at days 3 and 7, weeks 2 and 6, and months 3 and 6 postpartum. More than half of participants were single and had 10–12 years of education. Less than half of them had ever breastfed their children. No differences in knowledge, self-efficacy and intent to breastfeed scores were seen between two groups. Significant positive association was seen between self-efficacy and intent to breastfeed. Self-efficacy is an important predictor of intent to breastfeed among rural Hispanic women.
Defects and failure in ultra-fine copper magnet wire

The flow processes in wire drawing and extrusion are extremely nonhomogeneous and depend prominently on the die half-angle, the fractional reduction, the velocity vector, the friction shear factor between the die and the wire surface, and the strain hardening capacity of the drawing metal. Structural damage during wire drawing for a given microstructure has been found to correlate with the amount of hydrostatic stress developed. Nonmetallic inclusions such as oxide particles and more recently hard metallic inclusions can nucleate voids and cracks along with an insidious phenomenon called central burst or cupping. In addition, there appears to be a microstructural distinction around the wire centerline which has not been investigated in any systematic manner. In fact, microstructural characterization of drawn copper magnet wires seems to have received little or no consideration, especially utilizing transmission electron microscopy (TEM). This study represents an effort to rectify these shortcomings by applying light metallography (LM) and TEM to the study of a wide range of copper rod and drawn wire microstructures, including ultra-fine wire microstructures. The authors define ultra-fine wire to be smaller than 44 gauge (<50 {micro}m diameter; which is roughly one-third the diameter of a human hair).
Copper(II) coordination to ligands immobilized on photoluminescent porous silicon.

Increased preorganization can be achieved by immobilizing ligands on solid supports. Photoluminescent porous silicon, which can undergo facile hydrosilylation, was used as a support for open chain neutral N- and O-donor ligands. The abilities of these ligands to bind the divalent metal ions Ni 2 + , Cu 2 + , Zn 2 + , and Pb 2 + are examined. Immobilized ligands selectively complexed Cu(II) over the other metal ions studied. Ligands immobilized on photoluminescent porous silicon also removed a significant amount, up to 98%, of Cu(II) from copper(II)-spiked, organic-rich, seawater samples.
Level of confidence in diagnosis: clinical examination versus dermoscopy examination.

BACKGROUND Confidence is an important factor in decision making and may influence patient care. OBJECTIVES To evaluate whether short-training-based dermoscopy increases confidence in the diagnosis of skin lesions. METHODS AND MATERIALS After a 1-hour course on dermoscopy, 20 pairs of clinical and dermoscopic images of lesions were presented to 19 dermatology residents with little or no dermoscopy experience. After viewing the clinical image, they were asked to assess their confidence in the diagnosis in a seven-point scale, with 1 reflecting that the respondent was 100% confident that the lesion was benign, while number 7 reflected 100% confidence that it was malignant. The same technique was used for dermoscopic images. RESULTS Ten of the 20 pairs of evaluations showed a significant difference (p<.05). The largest differences were observed in lesions where clinical scores suggested that participants were uncertain about the diagnosis, but tended to decide that the lesion was benign after dermoscopy. Dermoscopy did not improve confidence in the evaluation of dysplastic lesions as well as lesions with obvious clinical diagnoses. CONCLUSIONS Short-training-based dermoscopy improved confidence in the diagnosis of clinically challenging skin lesions, but the impact was not demonstrable for clinically obvious lesions and dysplastic nevi.
Dynamic analysis of a composite-material flexible robot arm

Abstract Increased demands for higher productivity and improved quality of goods have required industrial robots to operate at high speed with greater precision. To meet these demands, robots should be lightweight, quick, and accurate. In this study these requirements are satisfied by inclusion of structural flexibility in the dynamic model of the robotic manipulator and implementation of advanced composite materials in the structural design. The focus of this study is a three-dimensional, revolute, compositematerial robot arm. A displacement finite element dynamic model is employed which includes all the coupling terms between the rigid and flexible motions and takes into consideration the axial, in-plane, and out-of-plane transverse deflections. The material damping of the laminated flexible link in both transverse directions is considered. The digital simulation results clearly demonstrate the advantage of incorporating advanced composite materials in the structural design of robotic manipulators. The effect of flexible motion on the rigid body motion is proven to be very important. It is also shown that there is a significant difference between the behavior of the geometrically linear and nonlinear models. Effects of fiber orientation and material orthotropy on the bending stress and displacements are also assessed. It is demonstrated that the inclusion of material damping in the dynamic model is an important factor in the design of flexible robot arms made of advanced composite materials.
Simulation-based homozygosity mapping with the GAW14 COGA dataset on alcoholism.

Background We have developed a simulation-based approach to the analysis of shared homozygous chromosomal segments and have applied it to data on allele sharing among alcoholics in a single Collaborative Study on the Genetics of Alcoholism pedigree. Our assessment of sharing involved the use of a single-nucleotide polymorphism (SNP) marker map provided by Affymetrix.
On stability and performance of parallel processing systems

The general problem of parallel (concurrent) processing is investigated from a queuing theoretic point of view.As a basic simple model, consider infinitely many processors that can work simultaneously, and a stream of arriving jobs, each carrying a processing time requirement. Upon arrival, a job is allocated to a processor and starts being executed, unless it is blocked by another one already in the system. Indeed, any job can be randomly blocked by any preceding one, in the sense that it cannot start being processed before the one that blocks it leaves. After execution, the job leaves the system. The arrival times, the processing times and the blocking structures of the jobs form a stationary and ergodic sequence.The random precedence constraints capture the essential operational characteristic of parallel processing and allow a unified treatment of concurrent processing systems from such diverse areas as parallel computation, database concurrency control, queuing networks, flexible manufacturing systems. The above basic model includes the G/G/1 and G/G/∞ queuing systems as special extreme cases.Although there is an infinite number of processors, the precedence constraints induce a queuing phenomenon, which, depending on the loading conditions, can lead to stability or instability of the system.In this paper, the condition for stability of the system is first precisely specified. The asymptotic behavior, at large times, of the quantities associated with the performance of the system is then studied, and the degree of parallelism, expressed as the asymptotic average number of processors that work concurrently, is computed. Finally, various design and simulation aspects concerning parallel processing systems are considered, and the case of finite number of processors is discussed.The results proved for the basic model are then extended to cover more complex and realistic parallel processing systems, where each job has a random internal structure of subtasks to be executed according to some internal precedence constriants.
Heart creatine kinase: heterogeneous composition of the mammalian M-B isoenzyme.

Abstract The distinctive cardiac isoenzyme of creatine kinase (CPK2) has been partially purified from rat heart homogenates. Ion-exchange chromatography on DEAE-Sephadex was used to separate CPK2 from other heart isoenzymes. The enzyme was denatured in 6.5 m guanidine HCl, and reassociated by dialysis into enzymatically active hybrids. Isoenzyme electrophoresis of the reactivated mixture resulted in the appearance of bands characteristic of skeletal muscle (M·M), heart (M·B), and brain (B·B) creatine kinases. The hybrids respectively corresponded to 35%, 42%, and 23% of the recovered activity. These results confirm the heterogeneity of mammalian heart CPK2, and substantiate its designation as M·B creatine kinase.
Episodic Secretion of Melatonin in Pre–X and Postpubertal Girls and Boys*

The concentration of melatonin was determined in serum samples obtained at 15-min intervals during a 4-h period from seven normal girls, 9.5-16.5 yr of age, and eight normal boys 9.0-168 yr of age. All samples were obtained between 0800 and 1300 h. An episodic pattern of melatonin secretion was found in all subjects. There was no significant (P > 0.1) difference between girls and boys as to number of episodes [3.1 ± 0.4 (±SD)vs. 3.4 ± 0.5 per 4 h), absolute melatonin increase (49.0 ± 6.7 vs. 50.4 ±4.1 pg⁄ml), or apparent melatonin half-life (20.3 ± 0.8 vs. 20.8 ± 1.0 min). The mean absolute increase during secretory episodes correlated (r = 0.843; P < 0.005) with the mean melatonin concentration per 4 h, and a significant (P < 0.05) inverse correlation (r = -0.508) was found between the mean percent increment of the melatonin secretory episode and the mean apparent melatonin half-life. A significant correlation between melatonin secretion and previously reported (22) episodic LH secretion was not found. I...
To breed or not to breed? Empirical evaluation of drug effects in adolescent rats.

Abstract The recent upsurge of research on adolescent rats raises the issue of the extent to which different methods of rodent procurement might affect results. Here, we examined the effects of acute and repeated dosing with two antipsychotics, haloperidol and clozapine, and Δ 9 -tetrahydrocannabinol [Experiments 1 and 2, respectively] in adolescent rats of both sexes that differed in shipping status (i.e., shipped from a commercial breeder at weaning or bred in-house). In each experiment, test drugs produced effects that were characteristic for their respective classes in previous studies with adult rodents. Both haloperidol and clozapine produced catalepsy and haloperidol decreased locomotion in shipped and bred rats of both sexes, with sensitization to haloperidol-induced catalepsy developing with repeated dosing. The most prominent between-status difference in this experiment was greater sensitivity of the shipped rats to haloperidol-induced changes in locomotor activity over a wider dose range, an effect that was especially evident in females. In Experiment 2, vehicle levels of motor activity were decreased in bred rats (which did not occur in Experiment 1), resulting in flattening of the Δ 9 -tetrahydrocannabinol dose–effect curve for this measure in bred rats of each sex. Acutely, Δ 9 -tetrahydrocannabinol produced antinociception, hypothermia and catalepsy in both groups of rats, with tolerance developing after repeated dosing. Status-related differences were sex-dependent. Whereas bred female rats were more sensitive to Δ 9 -tetrahydrocannabinol's antinociceptive effects, shipped male rats were more sensitive to its antinociceptive effects as well as to its hypothermic and cataleptic effects. Together, the results of these descriptive experiments suggest that between-status differences tend to be quantitative rather than qualitative. Further, these results suggest that careful attention to issues related to rodent procurement during adolescence is warranted and may help to account for divergent findings in different labs.
One-pot synthesis, encapsulation, and solubilization of size-tuned quantum dots with amphiphilic multidentate ligands.

We report one-pot synthesis, encapsulation, and solubilization of high-quality quantum dots (QDs) based on the use of amphiphilic and multidentate polymer ligands. In this “all-in-one” procedure, the resulting QDs are first capped by the multidentate ligand and are then spontaneously encapsulated and solubilized by a second layer of the same multidentate polymer upon exposure to water. In addition to providing better control of nanocrystal nucleation and growth kinetics (including resistance to Ostwald ripening), this procedure allows for in situ growth of an inorganic passivating shell on the nanocrystal core, enabling one-pot synthesis of both type-I and type-II core−shell QDs with tunable light emission from visible to near-infrared wavelengths.
Sex difference in polychlorinated biphenyl concentrations of burbot Lota lota from Lake Erie

Whole-fish polychlorinated biphenyl (PCB) concentrations were determined for 25 female and 25 male burbot Lota lota from Lake Erie. Bioenergetics modeling was used to investigate whether the sex difference in growth rate resulted in a difference in gross growth efficiency (GGE) between the sexes. For ages 6–13 years, male burbot averaged 28 % greater PCB concentrations than female burbot. The sex difference in PCB concentrations widened for ages 14–17 years, with male burbot having, on average, 71 % greater PCB concentrations than female burbot. Bioenergetics modeling results showed that the faster growth rate exhibited by female burbot did not lead to greater GGE in female individuals of the younger burbot and that the faster growth by female fish led to female GGE being only 2 % greater than male GGE in older burbot. Although our bioenergetics modeling could not explain the observed sex difference in PCB concentrations, we concluded that a sex difference in GGE was the most plausible explanation for the sex difference in PCB concentrations of burbot ages 6–13 years. Not only are male fish likely to be more active than female fish, but the resting metabolic rate of male fish may be greater than that of female fish. We also concluded that the widening of the sex difference in PCB concentrations for the older burbot may be due to many of the older male burbot spending a substantial amount of time in the vicinity of mouths of rivers contaminated with PCBs.
Topographic orientation on buffed polymeric substrates: The mechanism of wax buffing

This paper reports on the observation that buffed waxy polymers control the orientation of a vapor-deposited material subsequently deposited thereon. The insight into the mechanism of the buffing process of waxy polycrystalline polymers that these observations provide is presented. When a polycrystalline waxy polymer is buffed, grooves are formed. The dimensions of the grooves on the waxy polymer surface are substantially finer than the dimensions of the fibers of the buffing cloth. It is proposed that the buffing process stretches the polymer sufficiently to cause fibrillation, which results in the fine grooves observed. The fine grooves provide the topography necessary for orientation of the material deposited thereon.
From the heroic to the logistical: programming model implications of new supercomputing applications

High-performance computers such as the petascale systems being installed at DOE and NSF centers in the US are conventionally focused on "heroic" computations in which many processors are applied to a single task. Yet a growing number of science applications are equally concerned with "logistical" issues: that is, with the high-performance and reliable execution of many tasks that operate on large shared data and/or are linked by communication-intensive producer-consumer relations. Such applications may require the extreme computational capacity and specialized communication fabrics of petascale computers, but are not easily expressed using conventional parallel programming models such as MPI. To enable the use of high-performance computers for these applications, we need new methods for the efficient dispatch, coupling, and management of large numbers of communication-intensive tasks. I discuss how work on scripting languages, high-throughput computing, and parallel I/O can be combined to build new tools that enable the efficient and reliable execution of applications involving from hundreds to millions of uniprocessor and multiprocessor tasks, with aggregate communication requirements of tens of gigabytes per second. I illustrate my presentation by referring to our experiences adapting the Swift parallel programming system (www.ci.uchicago.edu/swift) for efficient execution in both large-scale grid and petascale cluster environments.
Experimental Study of Fracture of Glass:I, The Fracture Process

A concept of fracture is developed from experimental data. Fractures are found to originate at flaws or cracks of finite size, most of which are at the surface. The mechanism is one of crack propagation which begins when the local stress at the crack exceeds a minimum value. The rate of propagation increases with crack growth until a critical stress is reached at the crack tip which coincides with a limiting crack velocity. This limiting condition is identified with the boundary of the mirror surface of the fracture. From calculations to be presented in Part 11, the critical stress is estimated to be several million pounds per square inch.
An Experimental Study of the Reliability of the Bühler Baby Tests

a recognition of the importance of reliable tests at this level. Such scales, if reliable, would contribute much toward furnishing a sound basis for predicting future potentialities in the case of early adoption as well as give parents an idea of the mental level of their own infants, thus curbing the undue hopeful ness in case of parents with feeble-minded infants. Furthermore, such a scale of tests would furnish a valuable instrument for in
Developmental Parameters and Seasonal Phenology of Calepitrimerus vitis (Acari: Eriophyidae) in Wine Grapes of Western Oregon

ABSTRACT Developmental parameters of protogyne Calepitrimerus vitis (Nalepa) (Acari: Eriophyidae) were determined at 12, 15, 17, 22, 25, 28, 31, and 34°C to better understand seasonal activity, population growth, and ultimately more effectively manage pest mites in wine grapes. Net reproductive rate (Ro) was greater than zero at all temperatures with the maximum Ro (9.72) at 25°C. The lowest estimated Ro (0.001) occurred at 34°C. There was a gradual decrease in mean generation time (T) as temperatures increased from 17 to 31°C. The shortest and longest generation time was recorded at 31°C (T = 5.5 d) and 17°C (T = 17.5 d). Rates of natural increase were lowest at 17°C (0.035) and increased with increasing temperatures, respectively. The peak rate of natural increase value (0.141) was at 25°C. Estimations for minimum and maximum developmental thresholds were 10.51 and 39.19°C, respectively, while the optimum developmental temperature was 26.9°C. The thermal constant for egg to adult development was estimat...
Vapor-pressure-isotherm study of monolayer CO films adsorbed on BN.

We have measured detailed adsorption isotherms for CO films on BN at 18 temperatures between 50 and 75 K, for coverages in the first layer. The isotherms and isothermal compressibilities are very similar to those reported for CO on graphite (the corresponding features, however, appear approximately 20 K lower on BN). We use the similarity between the characteristics of the thermodynamic features of CO on these two substrates to tentatively identify the phases present, and to propose a phase diagram for CO on BN. Our adsorption results are also compared with data reported for Kr and for ${\mathrm{N}}_{2}$ films on BN; a possible explanation for why Kr behaves differently from either ${\mathrm{N}}_{2}$ or CO on BN is discussed.
A Novel Semidistributed Localization Via Multinode TOA–DOA Fusion

This paper presents a 2-D semi-distributed localization technique, which is based on the fusion of the positioning data estimated by multiple mobile nodes. The fusion is implemented in the local coordinate of one of the nodes (reference node) and improves the positioning performance of the desired node in the coordinate of the reference node. This paper introduces the proposed localization fusion technique. The fusion weights and positioning error are theoretically derived, and the efficiency of a suboptimal reference node selection method, the positioning error, and the position update rate are evaluated via simulations.
Rigging the Pepper Wreck. Part I—Masts and Yards

Discovered in 1993 at the mouth of the Tagus River, the SJB2 shipwreck—or ‘Pepper Wreck’—was tentatively identified as the Portuguese Indiaman Nossa Senhora dos Martires, lost in this place on its return voyage from Cochin, in India, on 14 September 1606. Its archaeological excavation led to a tentative reconstruction of the hull, based in contemporary texts on shipbuilding. Further analysis of these texts allowed us to propose a reconstruction of the rigging. © 2005 The Nautical Archaeology Society
FDA approval of Antiretroviral Agents: An Evolving Paradigm

The approach to traditional approval of antiretroviral agents in the United States has recently evolved. As in the past, companies can provide confirmatory clinical endpoint data following accelerated approval; alternatively, they can base their claim of efficacy primarily on data demonstrating a sustained reduction in plasma HIV-1 RNA. This change was fueled by issues associated with conducting long-term clinical endpoint trials given the rapidly changing treatment strategies for HIV and the availability of potent combination regimens. The Food and Drug Administration (FDA) hopes that this new approach will help direct more resources to ambitious, collaborative clinical trials. The rapid evolution of traditional approval also illustrates the importance of close collaboration between industry, academia, and the FDA. This field would not have moved forward so rapidly without consensus initiatives such as the Surrogate Marker Collaborative Group, which provided evidence suggesting that a virologic response, in terms of changes in HIV-1 RNA, is a strong predictor of clinical benefit.
Expert statistical testimony and epidemiological evidence: the toxic effects of lead exposure on children

The past two decades have seen a dramatic growth in the use of statisticians and economists for the presentation of expert testimony in legal proceedings. In this paper, we describe a hypothetical case modeled on real ones and involving statistical testimony regarding the causal effect of lead on lowering the IQs of children who ingest lead paint chips. The data we use come from a well-known pioneering study on the topic and the analyses we describe as the expert testimony are similar to ones that can be found in, major scientific journals. The battle of the experts in this hypothetical case resembles that which many encounter as expert witnesses. The paper concludes with some observations and advice.
Alterations in intestinal permeability after thermal injury.

• Alterations in intestinal permeability have been postulated to occur after thermal injury. We evaluated the status of intestinal permeability during the first 2 postburn weeks in 15 subjects by measuring the differential excretion of enterally administered lactulose and mannitol. The mean age and burn size of the patients were 32.7±3.6 years and 53.3%±5.1% of the total body surface area, respectively. Ten healthy volunteers were also studied. The lactulose-mannitol excretion ratio was 0.159±0.017 for the patients and 0.017±0.003 for controls. The increased ratio did not correlate with burn size or postburn day. Patients who developed significant clinical infections during their first 2 postburn weeks had lactulose-mannitol ratios on postburn day 2 that were significantly higher than those of controls and patients who did not develop infections. This suggests a relationship between susceptibility to infection and early alterations in intestinal permeability. ( Arch Surg . 1992;127:26-30)
Framework for Analyzing Garbage Collection

While the design of garbage collection algorithms has come of age, the anal- ysis of these algorithms is still in its infancy. Current analyses are limited to merely documenting costs of individual collector executions; conclusive results, measuring across entire programs, require a theoretical foundation from which proofs can be offered. A theoretical foundation also allows abstract examination of garbage collection, enabling new designs without worrying about implemen- tation details. We propose a theoretical framework for analyzing garbage collec- tion algorithms and show how our framework could compute the efcienc y (time cost) of garbage collectors. The central novelty of our proposed framework is its capacity to analyze costs of garbage collection over an entire program execution. In work on garbage collection, one frequently uses heap traces, which require determining the exact point in program execution at which each heap allocated object idiesi (becomes unreachable). The framework inspired a new trace gen- eration algorithm, Merlin, which runs more than 800 times faster than previous methods for generating accurate traces (7). The central new result of this paper is using the framework to prove that Merlin's asymptotic running time is optimal for trace generation.
Infant-feeding practices among African American women: social-ecological analysis and implications for practice.

Despite extensive evidence supporting the health benefits of breastfeeding, significant disparities exist between rates of breastfeeding among African American women and women of other races. Increasing rates of breastfeeding among African American women can contribute to the improved health of the African American population by decreasing rates of infant mortality and disease and by enhancing cognitive development. Additionally, higher rates of breastfeeding among African American women could foster maternal–child bonding and could contribute to stronger families, healthier relationships, and emotionally healthier adults. The purpose of this article is twofold: (a) to use the social-ecological model to explore the personal, socioeconomic, psychosocial, and cultural factors that affect the infant feeding decision-making processes of African American women and (b) to discuss the implications of these findings for clinical practice and research to eliminate current disparities in rates of breastfeeding.
Automatic vision programs from predicted features

Techniques are presented for automatically generating optimal vision programs from high- level task descriptions. Vision programs are the object models that describe strategies to recognize and locate objects in an image. The effectiveness of the program depends on the features used for recognition and the order in which the features are evaluated. We describe three probabilistic feature utility measures and a cost function based on program execution time that serve as the basis of our technique. Computation of such utility measures from a statistically representative sample of images has been demonstrated. Problems encountered in computing such measures from computer-generated images are described.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Postural contractile activities of human jaw muscles following use of an occlusal splint

Summary As induced by an occlusal splint over a period of 1 week, this study monitored surface electromyographic changes in the postural contractile activities of jaw elevator and depressor muscles in six healthy adults. The immediate effect of the occlusal splint was to increase the postural contractile activities of the suprahyoid muscles. All postural muscle activities showed wide-ranging biological variation, but the activities induced by the splint tended to stabilize within 1 week, with decreased postural activities in the masseter and anterior temporalis muscles, and increased postural activities in the suprahyoid muscles.
Observations of lattice curvature near the interface of a deformed aluminium bicrystal

Abstract Reported here is a study of the pattern of lattice curvature near the interface of deformed high-purity aluminium (99.9999%) bicrystals of specified crystallographic character (large-angle random). Curvature data are obtained from electron back-scattering diffraction pattern observations using orientation imaging microscopy. The concept of geometrically necessary dislocations (GNDs) is used as the central tool in the description of the observations. The samples studied were channel-die compressed perpendicular to the interface to plastic strain levels of 0.1 and 0.3. At a strain level of 0.1 the primary observation is the development of a pile-up of GNDs (i.e. lattice curvature) near the interface. At the higher strain level of 0.3, however, a dramatic change in the distribution is observed. The nature of this change suggests that the interface has absorbed (or emitted) some components of the nearby GND field. with an accompanying change in the local character of the interface towards a broader d...
Mechanisms of oligodendrocyte regeneration from ventricular-subventricular zone-derived progenitor cells in white matter diseases

White matter dysfunction is an important part of many CNS disorders including multiple sclerosis and vascular dementia. Within injured areas, myelin loss and oligodendrocyte death may trigger endogenous attempts at regeneration. However, during disease progression, remyelination failure may eventually occur due to impaired survival/proliferation, migration/recruitment, and differentiation of oligodendrocyte precursor cells (OPCs). The ventricular-subventricular zone (V-SVZ) and the subgranular zone are the main sources of neural stem/progenitor cells (NSPCs), which can give rise to neurons as well as OPCs. Under normal conditions in the adult brain, the V-SVZ progenitors generate a large number of neurons with a small number of oligodendrocyte lineage cells. However, after demyelination, the fate of V-SVZ-derived progenitor cells shifts from neurons to OPCs, and these newly generated OPCs migrate to the demyelinating lesions to ease white matter damage. In this mini-review, we will summarize the recent studies on extrinsic (e.g., vasculature, extracellular matrix, cerebrospinal fluid) and intrinsic (e.g., transcription factors, epigenetic modifiers) factors, which mediate oligodendrocyte generation from the V-SVZ progenitor cells. A deeper understanding of the mechanisms that regulate the fate of V-SVZ progenitor cells may lead to new therapeutic approaches for ameliorating white matter dysfunction and damage in CNS disorders.
Lightness Constancy: A Direct Test of the Illumination-Estimation Hypothesis:

Many models of color constancy assume that the visual system estimates the scene illuminant and uses this estimate to determine an object's color appearance. A version of this illumination-estimation hypothesis, in which the illuminant estimate is associated with the explicitly perceived illuminant, was tested. Observers made appearance matches between two experimental chambers. Observers adjusted the illumination in one chamber to match that in the other and then adjusted a test patch in one chamber to match the surface lightness of a patch in the other. The illumination-estimation hypothesis, as formulated here, predicted that after both matches the luminances of the light reflected from the test patches would be identical. The data contradict this prediction. A second experiment showed that manipulating the immediate surround of a test patch can affect perceived lightness without affecting perceived illumination. This finding also falsifies the illumination-estimation hypothesis.