cssi/SciSciGPT-SciSciNet huggingface dataset:
Multi-Wavelength Anomalous Diffraction Using Medium-Angle X-Ray Solution Scattering (MADMAX)

Proteins are dynamic molecules whose function in virtually all biological processes requires conformational motion. Direct experimental probes of protein structure in solution are needed to characterize these motions. Anomalous scattering from proteins in solution has the potential to act as a precise molecular ruler to determine the positions of specific chemical groups or atoms within proteins under conditions in which structural changes can take place free from the constraints of crystal contacts. In solution, anomalous diffraction has two components: a set of cross-terms that depend on the relative location of the anomalous centers and the rest of the protein, and a set of pure anomalous terms that depend on the distances between the anomalous centers. The cross-terms are demonstrated here to be observable and to provide direct information about the distance between the anomalous center and the center of mass of the protein. The second set of terms appears immeasurably small in the context of current experimental capabilities. Here, we outline the theory underlying anomalous scattering from proteins in solution, predict the anomalous differences expected on the basis of atomic coordinate sets, and demonstrate the measurement of anomalous differences at the iron edge for solutions of myoglobin and hemoglobin.
Denitrification in the oxygen minimum layer of the eastern tropical Pacific Ocean

Abstract Molecular nitrogen and nitrite are produced concurrently from nitrate-15N added to the oxygen-deficient and nitrite-rich water below the thermocline in the tropical eastern Pacific Ocean. Molecular nitrogen originates by reduction of nitrate (denitrification) and not from the oxidation of ammonia by nitrate or nitrite. The ratio of molecular nitrogen produced to nitrate-nitrogen lost varied from 0·1 to 0·8. Denitrification decreased by 58% with an increase in oxygen saturation from 0·4 to 3·5%.
Temperature dependence of the localized magnon mode in MnF2 : Co

Abstract The localized magnon mode in MnF 2 : Co was studied by far infrared resonance techniques. The halfwidth at 8 K is 1 cm -1 , about three times smaller than that obtained by other experimental methods. Therefore, accurate measurements of the temperature dependence are possible between 8 and 40 K. The temperature dependence of the effective g -factor is attributed to spin wave renormalization. The half width is magnetic field dependent at higher temperatures and can be approximated by a T 2 law.
Preserved verb generation priming in global amnesia

Abstract In the verb generation task, participants are presented with nouns and generate for each one an appropriate verb. Raichle et al. ( Cerebral Cortex , 1994, 4, 8–26) found that when participants generated verbs to repeated nouns, generation latencies were reduced and different patterns of brain activation were present. In order to examine whether verb generation priming is dependent or independent of declarative memory, verb generation priming was compared between 13 amnesic (seven with alcoholic Korsakoff's syndrome, six with other etiologies) and 19 control participants (10 with a history of alcoholism). Both amnesic and control participants became faster across blocks on repeated nouns and slowed when novel nouns were introduced. Priming was verb specific for both groups: it was equivalent whether generated to a repeated or a novel noun. Verb generation priming, therefore, can occur independently of declarative memory.
Toeplitz matrices commuting with tridiagonal matrices

Abstract we prove that if R is a nonscalar Toeplitz matrix Ri, j=r∦i−j∦ which commutes with a tridiagonal matrix with simple spectrum, then r k r 1 = u k-1 r 2 r 1 cos p u k-1 (cos p) , k=4, 5,…, with Uk the Chebychev polynomial of the second kind, where p is determined from cos p= 1 2 r 2 1 −r 1 r 3 r 2 2 −r 1 r 3 .
Relationships of cereal crops and other grasses

The grass family includes some 10,000 species, and it encompasses tremendous morphological, physiological, ecological, and genetic diversity. The phylogeny of the family is becoming increasingly well understood. There were two major radiations of grasses, an early diversification leading to the subfamilies Pooideae, Bambusoideae, and Oryzoideae, and a later one leading to Panicoideae, Chloridoideae, Centothecoideae, and Arundinoideae. The phylogeny can be used to determine the direction of changes in genome arrangement and genome size.
Teaching agents with human feedback: a demonstration of the TAMER framework

Incorporating human interaction into agent learning yields two crucial benefits. First, human knowledge can greatly improve the speed and final result of learning compared to pure trial-and-error approaches like reinforcement learning. And second, human users are empowered to designate "correct" behavior. In this abstract, we present research on a system for learning from human interaction - the TAMER framework - then point to extensions to TAMER, and finally describe a demonstration of these systems.
Binaural interactions in cortical area AI of cats reared with unilateral atresia of the external ear canal.

Abstract Binaural interactions were recorded in auditory cortical (AI) neurons of anesthetized adult cats that had unilateral atresias created shortly after birth by surgically ligating and cutting one external ear canal. At the time of the recording experiment, the atresia and associated debris were removed and tones were delivered to both tympanic membranes via a sealed and calibrated acoustic system. The majority of neurons recorded were in the cortex ipsilateral to the previously occluded ear. Thresholds for monaural stimulation of either the operated or unoperated ear were within normal range although thresholds to stimulation of the previously operated ear tended to occupy the upper end of the normal distribution. Monotonie and nonmonotonic spike count-vs-intensity functions derived from responses to monaural stimulation of the atretic ear were indistinguishable in their shape from those recorded in normal cats. All binaural classes were represented in our sample in proportions similar to those reported in cats with two normal ears. The forms of the functions relating spike count to interaural intensity differences and interaural phase differences were essentially the same as those seen in normal animals. The main binaural deficit observed under these conditions was a shift in the interaural intensity difference to which an AI neuron was most sensitive. The intensity needed for a stimulus to the atretic ear to participate in the binaural response was as much as 50 dB higher than that at the opposite normal ear in contrast to the nearly equal SPLs required for binaural interactions in cats with two ears intact. It was suggested that elevated thresholds at the previously operated ear could account for much of the shift observed.
CVD OF SOLID OXIDES IN POROUS MEDIA FOR CERAMIC MEMBRANE PREPARATION OR MODIFICATION. EXPLICIT SOLUTIONS FOR DEPOSITION CHARACTERISTICS

Abstract A theoretical analysis of modified chemical vapor deposition (MCVD) of solid oxides in porous media for ceramic membrane preparation and/or modification is presented in this paper. Semi-analytical solutions have been obtained to describe the evolution of solid deposit profiles inside porous substrates, using a phenomenological model that takes into account intrapore precursor diffusion, chemical reaction and pore geometry change. Explicit equations have been derived which correlate the three main deposition characteristics, deposit location, deposit zone thickness and pore closure time to the CVD experimental parameters and substrate pore structure. Such explicit equations provide better insight into this unique CVD process for advanced materials synthesis and are very useful in practical applications. A comparison of the semi-analytical solutions with a numerical solution based on the finite element method is also presented. The semi-analytical solutions are in good agreement with the numerical solutions, especially under the conditions used for ceramic membrane preparation and/or modification.
Long term follow-up in two cases of transvestism treated with aversion therapy

Abstract Two case studies of behavior therapy with transvestites are described. Aversive conditioning procedures with variations were employed along with programs for increasing appropriate gender-related behavior. While therapy was successful in the short term follow-up, long term follow-up revealed total relapse in both cases. The implications of this outcome are discussed with regard to therapy strategies with transvestism.
Receptor redistribution induced by hormones and neurotransmitters: Possible relationships to biological functions

Abstract Studies on the patterns and mobilities of various receptors for polypeptide hormones have indicated that generally the occupied receptors appear to be initially distributed uniformly over the cell surface and quickly form clusters which are subsequently internalized. In contrast, clusters of opiate receptors appear to form only slowly and they do not become internalized. It is now recognized that receptor microaggregation or cross-linking, perhaps independent of internalization, may be important for hormonal action in some systems. On the other hand, in certain other systems of for certain special functions, internalization of receptor-bound proteins may serve as a selective transport system which directs specific ligands to specific subcellular organelles.
Religion and science: The wandering Jew and Methuselah

Abstract Whereas religion emphasizes the superiority of the spiritual over the physical life, science aims at lengthening and improving life without regard to how it is spent. Christianity traditionally saw virtue in the shortest possible life, the sooner to be joined with God. The legend of the Wandering Jew, in demonstrating longevity to be a curse, dramatizes this theme. Science takes a very different view of longevity, finding in Methuselah a symbol of its quest. Several twentieth-century writers—Atherton (Black Oxen), Shaw (Back to Methuselah), Huxley (After Many a Summer Dies the Swan), Clark (The City and the Stars), and Stewart (The Methuselah Enzyme)— portray characters who, with the help of science, overcome the aging process. These writers seem to find the implications of endless life troubling. However, despite their reservations about greatly prolonged life, they express an enthusiasm for science and its infinite possibilities, underscoring their ambivalence about longevity .
Dynamical Aspects of Extratropical Tropospheric Low-Frequency Variability

Abstract The nature of extratropical tropospheric low-frequency variability remains an important, unresolved problem in the overall dynamics of the climate system. Primarily, this is due to the complexity of dynamics operating on low-frequency timescales of 10–100 days; both synoptic- and planetary-scale dynamical processes are fully active and strongly interactive. This review explores two issues that frequently arise in the study of low-frequency variability, and emphasizes the continuing value of idealized dynamical models in interpreting low-frequency variability. The first issue concerns the extent to which the extratropical atmosphere supports planetary-scale instabilities, and whether a simple picture of such instabilities can be developed. It is argued that under certain circumstances such instabilities do exist, and result from the accumulation of stationary wave energy in local resonant cavities that emerge in zonally varying barotropic flow. The second issue concerns the interaction of synoptic...
Nongeostrophic theory of zonally averaged circulation. II - Eliassen-Palm flux divergence and isentropic mixing coefficient

A diagnostic study of Eliassen-Palm flux divergence and isentropic mixing coefficient (Kyy) in the stratosphere is performed for different seasons and for both hemispheres, based on the nongeostrophic theory of zonally averaged circulation of Tung (1986). An easily implementable procedure is described which yields a Kyy field that is consistent with advective transport. It is shown that the resultant time- and space-varying structure of Kyy leads to improved simulation of stratospheric species whose distributions are affected by dynamical transport. In particular, it is shown that the simulation of nitric acid is more satisfactory than previous model calculations.
Magnetohydrodynamic coolant flows in fusion reactor blankets

Abstract The magnetohydrodynamic flow of a liquid metal coolant through a square duct is modeled in three dimensions to study the development of the flow in the entry region of a fusion reactor blanket. The effect of various wall conductivity configurations on the heat transfer capability and pressure gradient requirements is also investigated. The three momentum, three induction, pressure and energy equations are cast in parabolic form and integrated numerically by the use of a marching procedure in the stream direction. Mesh size limitations restrict the flow to low Hartmann numbers. The results show a smooth and rapid development of the flow over a length which is sensitive to the Hartmann number. Velocity and temperature profiles are flattened and heat transfer coefficients are increased. The calculations for mixed wall conductivities show that it is possible to increase heat transfer capabilities of the flow significantly by selectively insulating the corners of the ducts.
Frequent detection of acute HIV infection in pregnant women.

Background: Universal prenatal HIV antibody testing, which does not detect acute HIV, is standard for pregnant women in the United States. Unrecognized HIV acquisition during pregnancy may result in higher rates of perinatal transmission. Objective: To determine the prevalence of acute (antibody-negative) HIV infection in pregnant women and to assess the potential for prompt initiation of antiretroviral therapy to prevent perinatal transmission. Methods: From 1 November 2002 to 30 April 2005, all publicly funded HIV testing sites participated in North Carolina's Screening and Tracing Active Transmission (STAT) Program, which retested all specimens that were HIV antibody negative for HIV RNA using specimen pooling. All patients with acute HIV infection were immediately traced for evaluation, confirmatory testing, counseling, and referral services. For this study, all pregnant women with acute HIV were immediately initiated onto antiretroviral therapy and followed prospectively for pregnancy outcomes. Results: During the study period, 443 women were HIV positive by antibody testing; 15 were HIV antibody negative but positive by RNA assay and of these five were pregnant at the time of testing. The pregnant women received antiretroviral drugs and delivered HIV-uninfected infants. Maternal testing records of all six HIV-infected infants born in North Carolina showed three mothers with chronic HIV infection and three HIV antibody negative at private prenatal testing facilities. Conclusions: In resource-rich settings, a substantial proportion of residual perinatal transmission may be from HIV acquisition during pregnancy. Standard antibody tests miss acute HIV infection and so algorithms that include pooled HIV RNA testing may improve its detection and represent a further opportunity to prevent perinatal transmission.
Why Ukraine is so poor, and what could be done to make it richer

Ukraine has an economy today that is not much larger than in 1990. The main explanation is that Ukraine had no economic policy in the first three years of its independence, 1991–1994. The Soviet economic system lingered, but the government allowed large fiscal deficits, which it financed with monetary emission, causing hyperinflation of 10,200% in 1993. Meanwhile, a small number of clever operators bought commodities either in Russia or Ukraine at low state-controlled prices and sold them on free markets at home or abroad at several times higher prices. These people became oligarchs, and they have dominated Ukraine’s economy and politics until the present. Corruption became particularly brazen under President Viktor Yanukovych. Today, Ukraine has at least a chance to break out of this vicious circle of corruption and chronic economic underperformance subject to making some fundamental changes in the country’s economic policies.
Designing a public touchscreen display system for iSchool community

This project aims to design and develop a public touchscreen display system for the School of Information Sciences at the University of Pittsburgh in order to provide research talks, events, announcements, job postings and other useful information to local community members. The motivation was to let students of the iSchool embrace information and experience technology in their daily environment and help them to understand the connection among people, information, and technology. Based on the project context and user requirements, target features were defined and design guidelines were formulated. A prototype was developed and then evaluated through usability testing and observation to validate the features and guidelines. Results showed that the system has met users' requirements and conforms to the context of the iSchool. This article provides some insights into designing a public touchscreen display system for educational institutions such as this iSchool.
Toxicity of aluminum exposure during lactation to the maternal and suckling rabbit

Abstract To assess aluminum toxicity to the Al-exposed lactating organism and her suckling offspring, lactating rabbits received 20, sc, Al lactate injections (0, 25, 100, 400, or 800 μmol Al/kg/inj) between Days 4 and 29 postpartum. Offspring were weaned Day 30 postpartum. Weight gain in the first 12 postnatal weeks was slightly greater in 25 and 100 μmol offspring and somewhat less in 400 and 800 μmol offspring than in controls. Significant weight loss was seen in the 400 and 800 μmol group does. Does in the 800 μmol group died within 10 days after completion of the Al injections. Every fifth day postpartum, after 24-hr isolation of the doe from her offspring, a milk sample was obtained and the weight of milk consumed by the offspring was determined. Does receiving higher Al exposures had increased milk Al concentration [e.g., 6.0 μg/g (220 μ m )] in the 800 μmol group vs 1.3 μg/g in controls) and decreased milk production (105 g/day vs 219 g/day). Based on milk consumption and milk Al concentration, no more than 2% of the Al injected into the does in any of the treatment groups was found in the milk 24 hr later. During the 1 month postpartum, each suckling offspring of a 800-μmol group doe received a cumulative oral Al exposure of about 300 μmol/kg, whereas each doe received a total of 16,000 μmol/kg, sc, and approximately 60,000 μmol/kg in her diet. When measured 1 week after weaning, offspring had no elevations in tissue Al concentration, whereas their does had a considerable increase 5 and 9 weeks after weaning. Other than the decreased weight gain of 400 and 800 μmol offspring, probably caused by the decreased milk production of the does, no detrimental effects of the Al treatment of lactating does were observed in the offspring. The lack of effects in the offspring is probably explained by their low levels of Al exposure from milk compared to typical adult rabbit Al intakes.
Block Copolymer Micelles for Controlled Delivery of Glycolytic Enzyme Inhibitors

Purpose To develop block copolymer micelles as an aqueous dosage form for a potent glycolytic enzyme inhibitor, 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO).
Mössbauer effect evidence for the clustering of carbon atoms in iron-carbon martensite during aging at room temperature☆

Abstract Mossbauer spectra of an iron −1.85 at% carbon martensite show a marked change as a result of a short room temperature annealing of the specimen. The effect is interpreted as due to the clustering of carbon atoms in the martensite.
Thermodynamic Analysis of Wall Effects on Phase Stability and Homogeneous Nucleation in Nanotubes Containing Superheated Liquid

Rapid heating or sudden depressurization can create highly superheated liquid conditions in stationary or flowing liquid in nanochannels. In these situations, the phase stability of the liquid and the conditions for the onset of bubble nucleation are important factors in the fluid behavior in applications. In the investigation summarized here, a statistical thermodynamics analysis is used to derive a modified version of the Redlich-Kwong fluid property model that accounts for attractive forces between the solid wall surface atoms and liquid molecules in the fluid within a nanochannel. In this model, the wall-fluid attractive forces are quantified in terms of Hamaker constants, which makes it possible to assess the effect of wall-fluid force interactions on the spinodal conditions for a variety of fluid and surface material combinations. This investigation focuses on the application of the aforementioned model to high aspect ratio (parallel plate) channels where a second wall is placed parallel to the first at distances varying in scale from nanometers to micrometers. At large channel widths the fluid properties exhibit wall effects very near each wall with bulk fluid property values being predicted in the center of the channel. As the channel width decreases, the fluid in the center of the channel begins to feel the effects of both walls and the properties deviate from the bulk values throughout the channel; importantly, the spinodal temperature increases significantly above the bulk fluid value. Fluid property profiles are developed for common combinations of walls and fluids, and properties are investigated as a function of non-dimensionalized distance within the channel across various channel widths. The results of this analysis imply that in nano- and micro-passages and near walls with nano-to micro-scale roughness, fluid may experience a stabilizing effect due to its proximity to nearby walls.Copyright © 2008 by ASME
Max-Plus Stochastic Processes

This paper is concerned with processes which are max-plus counter-parts of Markov diffusion processes governed by Ito sense stochastic differential equations. Concepts of max-plus martingale and max-plus stochastic differential equation are introduced. The max-plus counterparts of backward and forward PDEs for Markov diffusions turn out to be first-order PDEs of Hamilton-Jacobi-Bellman type. Max-plus additive integrals and a max-plus additive dynamic programming principle are considered. This leads to variational inequalities of Hamilton-Jacobi-Bellman type.
Learning Styles: What We Know and What We Need

Abstract In this essay, the authors argue that understanding students' learning styles is likely to (a) help teachers recognize the causes of some academic problems, and (b) lead to better planned, differentiated instruction. Learning style, as defined by Dunn and Dunn, is highlighted, and research supporting its effectiveness is outlined. By citing numerous examples, the author proposes that identifying patterns of individual learning needs and responding to students' learning styles can result in improved academic achievement.
Contribution of Activity Coefficients of Methylene Homologues to Odor and Flavor Detection Thresholds

Odor and flavor detection thresholds D were related to their activity coefficients at infinite dilution in water, γ w , with constant values of Dγ W (apparent threshold activity) for methylene homologues of carbon number up to about 8 or 5. Chem. Senses 20 : 471-475, 1995.
Taxol-induced neuropathy: further ultrastructural studies of nerve fibre changes in situ

Nerve fibre changes have been further monitored morphologically in rat sciatic nerves which had been locally injected with taxol, an antimitotic drug known to promote microtubule assembly. Taxol caused a slowly progressive accumulation of microtubules over a three week period of experimentation, the effect being more pronounced in Schwann cells. Schwann cells of myelinated fibres became detached from nodes of Ranvier and were applied to naked internodes as bulbous cells replete with microtubules and smooth endoplasmic reticulum (ER). In some cases, the smooth ER was believed to arise from rough ER after the displacement of ribosomes. These cells also contained myelin fragments from the original internodes. Microtubules displayed unique relationships with cytoplasmic membranes and were seen to exist as regular 22 nm microtubules, as obliquely sectioned profiles or as incomplete, trough-shaped structures. Internodes devoid of myelin were common, and naked axons covered only by basal lamina appeared swollen and invariably contained an abundance of microtubules. Schwann cells lacking axons had multilobate nuclei and possessed complex arrays comprising smooth ER membranes and microtubules. In areas where microtubules were absent, these membranes compacted to form intracellular myelin. Intermediate filaments existed in lower numbers than normal within both axons and Schwann cells. Arrested mitoses were occasionally seen and it is speculated that together with the immobilization of the cell by the over-abundant polymerization of tubulin, incomplete mitosis was an underlying cause for the observed lack of remyelination over the 21-day period of study. These results suggest that perturbations in microtubule synthesis might dramatically affect Schwann cell behaviour and myelin proliferation.
In vitro lipofection with novel series of symmetric 1,3-dialkoylamidopropane-based cationic surfactants containing single primary and tertiary amine polar head groups

A novel series of symmetric double-chained primary and tertiary 1,3-dialkoylamido monovalent cationic lipids were synthesized and evaluated for their transfection activities. In the absence of the helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), only the primary and tertiary dioleoyl derivatives 1,3lmp5 and 1,3lmt5, respectively elicited transfection activity. This is a striking difference between symmetrical 1,2-diacyl glycerol-based monovalent cationic lipids that always found both dioleoyl and dimyristoyl analogues being efficient transfection reagents. In the presence of helper lipid, all cationic derivatives induced marker gene expression, except the dilauroyl analogues 1,3lmp1 and 1,3lmt1 that elicited no transfection activity. Combining electrophoretic mobility data of the lipoplexes at different charge ratios with transfection activity suggested two requirements for high transfection activity with monovalent double-chained cationic lipids, that is, binding/association of the lipid to the plasmid DNA and membrane fusion properties of the lipid layers surrounding the DNA.
Null cut loci of spacelike surfaces

The null cut locus of a spacelike submanifold of codimension 2 in a space-time is defined. In globally hyperbolic space-times, it is shown that the future (past) null cut locusc n + (H) [c n - (H)] of a compact, acausal, spacelike submanifoldH of codimension 2 is a closed subset of the space-time, and each pointx∈ c n + (H) is either a focal point ofH along some future-directed null geodesic meetingH orthogonally or there exist at least two null geodesics fromH tox, realizing the distance betweenH andx or both. Also, it can be shown that the assumptions of the Penrose's singularity theorem for open globally hyperbolic space-times may be weakened to the space-times which are conformal to an open subset of an open globally hyperbolic space-time.
Fracture toughness parameters and elasticplastic analysis of non-moderate fracture conditions using finite element methods☆

Abstract Non-moderate fracture conditions of load and geometry, in which plastic zones remain neither constant in size nor uniform in shape as load or crack progress, were simulated using two dimensional elasticplastic finite element calculations. Comparison of conventional crack extension energy rate G, as determined by elastic fracture mechanics and by a compliance method suitable for non-linear deformation, is made with Rice's ‘J integral’, with crack opening displacement, and also with plastic strain energy. The relationship of crack opening displacement to crack extension force can be linearised by selecting values of crack opening displacement at locations which nominally follow the calculated location of the elastic-plastic boundary on the crack face. The relatively large plastic zones associated with high loading are shown, and the field determined in the usual manner from incremental load increases is compared with the field resulting when only two steps are used to reach the same load. Some insight is gained into the use of finite element calculations for determining, from among the various fracture indicators, a single parameter capable of describing nonmoderate fracture conditions.
Coherent nanodiffraction from phase objects: carbon nanotubes

Abstract Electron diffraction patterns obtained with a coherent incident beam of diameter 1 nm or less do not, in general, show a center of symmetry even for thin phase objects. Experimental observations of nanodiffraction patterns obtained from the walls of carbon nanotubes show asymmetries in the intensities of the first-order reflections from the carbon-layer stacking periodicity which are in agreement with calculations from a simple theoretical model. It is suggested that the measurement of such asymmetries may provide evidence regarding the structures of nanotubes of non-circular cross-section and of the end regions of tubes.
A Domain Wall Model for Hysteresis in Ferroelastic Materials

We develop a model that quantifies constitutive nonlinearities and hysteresis inherent to ferroelastic compounds, with emphasis placed on shape memory alloys. We formulate the model in two steps. First, we use the Landau theory of phase transitions to characterize the effective Gibbs free energy for single-crystal and polycrystalline ferroelastics. The resulting nonlinear equations model equilibrium material behavior in the absence of impurities. Second, we incorporate pinning losses to account for the energy required to move domain walls across material inclusions. The full model is analogous to those developed by Jiles and Atherton for ferromagnetic compounds and Smith and Hom for ferroelectric materials. We illustrate aspects of the model through numerical simulations and comparisons with experimental stress-strain data.
Retrieval by classification of images containing large manmade objects using perceptual grouping

Abstract This paper applies perceptual grouping rules to the retrieval by classification of images containing large manmade objects such as buildings, towers, bridges, and other architectural objects. The semantic interrelationships between primitive image features are exploited by perceptual grouping to extract structure to detect the presence of manmade objects. Segmentation and detailed object representation are not required. The system analyzes each image to extract features that are strong evidence of the presence of these objects. These features are generated by the strong boundaries typical of manmade structures: straight line segments, longer linear lines, coterminations, “L” junctions, “U” junctions, parallel lines, parallel groups, “significant” parallel groups, cotermination graph, and polygons. A K -nearest neighbor framework is employed to classify these features and retrieve the images that contain manmade objects. Results are demonstrated for two databases of monocular outdoor images.
Dual-tracer scintigraphy and subtraction studies in the diagnosis of hepatocellular carcinoma

Dual tracer scintigraphy (DTS) (technetium 99m [99mTc] sulfur colloid and gallium 67 citrate [67 gallium citrate]) of the liver and computer subtraction studies (SS) were performed in 26 patients subsequently proven to have hepatocellular carcinoma (HCC) and 32 patients with cirrhosis and focal defects on the colloid scan, with no evidence for HCC after a complete evaluation and a 2-year follow-up period. Both DTS and SS had a sensitivity of 96% and a specificity of 90.6% for HCC. There were three false positive cases (9.4%), two of which were occult abscesses. The predictive value of a positive test was 89% and that of a negative test was 97%. The smallest tumor detected measured 2 cm in diameter and was only visualized with the SS. In the clinical setting, when HCC is suspected (a situation in which tumors are usually larger than 2 cm and the pretest probability of disease is between 20% and 60%) the DTS and SS is an excellent test for the diagnosis or exclusion of HCC. It does not appear to have a role in screening programs.
Prostate segmentation in ultrasound images with deformable shape priors

Automated prostate segmentation in ultrasound images is a challenging task due to speckle noise, missing edge segments, and complex prostate peripheral anatomy. In this paper, a Bayesian prostate segmentation algorithm is presented. It combines both prior shape and image information for robust segmentation. In this study, the prostate shape was efficiently modeled using deformable superellipse. A flexible graphical user interface has been developed to facilitate the validation of our algorithm in a clinical setting. This algorithm was applied to 66 ultrasound images collected from 8 patients. The resulting mean error between the computer-generated boundaries and the manually-outlined boundaries was 1.39 ± 0.60 mm, which is significantly less than the variability between human experts.
Hierarchical gradient methods for nonlinear LSQ problems

The idea of hierarchical gradient methods for optimization is considered. It is shown that the proposed approach provides powerful means to cope with some global convergence problems characteristic of the classical gradient methods. Concerning global convergence problems, four topics are addressed: The “detour” effect, the problem of multiscale models, the problem of highly ill-conditioned objective functions, and the problem of local-minima traps related to ambiguous regions of attractions. The great potential of hierarchical gradient algorithms is revealed through a hierarchical Gauss-Newton algorithm for unconstrained nonlinear least-squares problems. The algorithm, while maintaining a superlinear convergence rate like the common conjugate gradient or quasi-Newton methods, requires the evaluation of partial derivatives with respect to only one variable on each iteration. This property enables economized consumption of CPU time in case the computer codes for the derivatives are intensive CPU consumers, e.g., when the gradient evaluations of ODE or PDE models are produced by numerical differentiation. The hierarchical Gauss-Newton algorithm is extended to handle interval constraints on the variables and its effectiveness demonstrated by computational results.
Solution of parabolic equations using an eigenvalue method for time advancement

Abstract The use of numerical time advancement techniques typically involve development of matrix systems that are solved in timestepped from. In this paper, an eigenvalue approach is used to exactly solve the fundamental matrix system. In this way, numerical error occurs only in the spatial derivative terms, and not the temporal term.
Variational Principles for Constrained Systems: Theory and Experiment

In this paper we present two methods, the nonholonomic method and the vakonomic method, for deriving equations of motion for a mechanical system with constraints. The resulting equations are compared. Results are also presented from an experiment for a model system: a ball rolling without sliding on a rotating table. Both sets of equations of motion for the model system are compared with the experimental results. The effects of various forms of friction are considered in the nonholonomic equations. With appropriate friction terms, the nonholonomic equations of motion for the model system give reasonable agreement with the experimental observations.
A multimedia independent approach to learning.

ALTHOUGH independent instruction promises greater effectiveness, research regarding this method of instruction has been meager. A comparative study of matched groups resulted in no significant difference in performance by the tape-taught section (Popham, 1961). Stewart (1965) examined student achievement in both traditional and independent study groups and found no significant differences. In McKeachie’s (1951) study, student anxieties about achievement were recognized in the experimental group and the instructors were able to help students progress in the various aspects of achievement. A study (Griffen et al., 1965) at the Montefiore Hospital in New York City reported that clinical nursing instruction by television produced positive results. Better nursing care was accomplished and one instructor could teach 15 students compared to only 10 in the conventional method. Postlethwait et al. (1964), who had extensive experience with multimedia approaches at Purdue University, stated that the audio-tutorial system of teaching improves learning, allows for more course content, and facilitates the accommodation of up to twice the number of students. They believed that this could be accomplished without dehumanizing the student-teacher relationship.
Gender Attribution in Online Video Games

Demographic research and anecdotal evidence suggest that, historically, games have been dominated by male players. However, newer research shows gains by female players, especially in online games. Therefore, how gamers perceive the masculinity of other gamers in game has become relevant. Two experiments examine how two variables - game genre and player skill - inform gender perception in online games. Results from both studies show that game genre is a salient cue for gender perception, but that perception of player skill is not. A number of gender differences in perceptions of player skill and the relationship between genre and perceptions of player masculinity are also identified. These findings are an important first step in understanding the perception of others in online entertainment environments.
Downregulation of the CCAAT-Enhancer Binding Protein β in ΔFosB Transgenic Mice and by Electroconvulsive Seizures

Previous studies demonstrate that chronic, but not acute electroconvulsive seizures (ECS), increases levels of deltaFosB, a long-lasting transcription factor, in the hippocampus, and this effect correlates with the slow onset and long-lasting clinical effects of antidepressant treatment. To understand how deltaFosB mediates long-term plasticity in the hippocampus, we analyzed the gene expression profile of inducible transgenic mice expressing deltaFosB with a highly sensitive microarray assay and a customized computer analysis program. The CCAAT-enhancing binding protein-beta (C/EBPbeta) was identified as one of the genes downregulated by deltaFosB in the hippocampus. The downregulation of C/EBPbeta in the inducible deltaFosB transgenic mice was confirmed by other quantitative assays including real-time RT-PCR and low density dot blotting. Analysis of the C/EBPbeta expression in the hippocampus of rats treated with ECS revealed that the C/EBPbeta mRNA was also downregulated by chronic, but not acute ECS administration, the most effective treatment for depression. Given the reported role of C/EBPbeta in behavioral conditioning models, it is possible that the deltaFosB-mediated downregulation of C/EBPbeta in the hippocampus may be a molecular mechanism by which antidepressants alleviate some of the symptoms of depressed patients.
Induction Hardening 5150 Steel: Effects of Initial Microstructure and Heating Rate

Induction heating has permitted great progress in the surface hardening of a wide variety of steels, but results in a wide range of local thermal cycles. The metallurgical changes during rapid heating and cooling have not been sufficiently studied with respect to heating rate and prior microstructure. In the present investigation, induction dilatometry was performed on 5150 steel with ferrite-pearlite and tempered martensite initial microstructures to assess effects of experimentally controlled prior microstructure and heating rate on austenitization kinetics. Heating rates were varied from 0.3 to 300 °C/s to simulate industrial processes, and post-hardening metallography and hardness testing were performed. Results show that the transformation kinetics for prior ferrite-pearlite microstructures are significantly slower than for prior tempered martensite microstructures, although hardness is equivalent for a given thermal cycle. Metallographic evidence suggests significant remnant segregation of chromium in regions of pearlitic cementite (enriched); evidence of segregation was not observed metallographically for prior tempered martensite. Diffusion-based transformation simulations support observed ferrite-pearlite alloy segregation, suggest residual alloy segregation is possible for prior tempered martensite, and can be used to tailor austenitization thermal cycles to process requirements. Detailed time and temperature-dependent local microstructure development results from this study are directly applicable to practical induction hardening simulations.
An existence theorem for strong liftings

Let (2, CL) be a couple consisting of a locally compact Hausdorff space 2 and a positive Radon measure p on 2. By Pm@, CL) we denote the algebra of bounded P-measurable functions on 2 in the sense of Bourbaki [I], by L”(Z, cl) their classes modulo locally negligible functions, and by N” the essential supremums norm on SP’(Z, p) and L”(Z, p); L”(Z, p) is a Banach algebra and a complete vector lattice [2, Chap. I].
Post-Compliance Touch: An Incentive for Task Performance

That a brief touch increases compliance to a request is well documented, but the effect of touch after compliance has already been obtained has not been investigated. The current experiment tested the effects of post-compliance touch on subjects' willingness to respond to items on a lengthy and difficult survey. A total of 104 women and 94 men, approached at random in an American university student union, agreed to participate in a survey of social attitudes. Subjects rated their amount of agreement or disagreement with 150 statements about social issues such as discrimination, abortion, euthanasia, politics, and religion. The effects of touch were assessed in two ways: by the number of survey items completed and the nature of these responses. Results indicated that both male and female subjects who were touched completed significantly more items than nontouched subjects, but there was no difference in the nature of their responses.
Programmable frequency reference for subkilohertz laser stabilization by use of persistent spectral hole burning.

We report what is believed to be the first demonstration of laser frequency stabilization directly to persistent spectral holes in a solid-state material. The frequency reference material was deuterated CaF(2): Tm(3+) prepared with 25-MHz-wide persistent spectral holes on the H(6)(3)?H(4)(3) transition at 798 nm. The beat frequency between two lasers that were independently locked to persistent spectral holes in separate crystal samples showed typical root Allan variances of 780+/-120Hz for 20-50-ms integration times.
Distribution and abundance of nutrient transporter mRNA in the intestinal tract of the black bear, Ursus americanus.

Abstract End products of digestion are absorbed by the body through the action of transporter proteins expressed on the apical membrane of intestinal epithelial cells. We investigated the mRNA abundance and distribution of a peptide transporter (PepT1), a glucose transporter (SGLT1), two amino acid transporters (NBAT and bo,+AT), and a digestive enzyme, aminopeptidase N (APN), in the intestinal tract of black bears (Ursus americanus). Intestinal total RNA was isolated from 10 bears and abundance of PepT1, SGLT1, NBAT, bo,+AT, and APN mRNA were determined by Northern blots. Abundance of PepT1 (P
Control of myocardial levels of CoA and carnitine.

Abstract Control of myocardial levels of CoA and carnitine were studied in rat heart. Hearts removed from diabetic animals had increased levels of total CoA. The rise in CoA was greater in animals receiving 60 mg alloxan/kg than in those receiving 37.5 mg alloxan/kg. The increase was evident as carly as 6 h after injection of 60 mg alloxan/kg and by 1 day following injection of 37.5 mg alloxan/kg. The higher levels of CoA were maintained for 21 days of diabetes following injection of the lower doses of alloxan. Control of CoA synthesis was studied in the isolated perfused heart. Synthesis was strongly inhibited by insulin and was accelerated by perfusing with no exogenous substrate. Addition of cysteine to the no substrate hearts caused an 8-fold increase in CoA synthesis. The major control of the pathway appeared to occur in the cytosol with changes in the rate of conversion of 14 C-pantothenic acid to a 14 C-intermediate. More than 90% of the pantothenic acid and 95% of the labelled intermediate were in the cytosolic compartment. However, changes in the levels of CoA occurred in both cytosol and mitochondria. These data indicated that much of the increase in CoA synthesis in diabetic animals could result from lower levels of insulin. Tissue levels of carnitine decreased in hearts from diabetic animals. The decrease was not apparent for several days in mildly diabetic animals receiving 37.5 mg alloxan/kg and only after 48 h in severely diabetic animals receiving 60 mg alloxan/kg. In each case, low tissue levels of carnitine were associated with reduced serum carnitine. Carnitine transport into isolated perfused hearts consisted of both a saturable and non-saturable component. The saturable component obeyed Michaelis-Menten kinetics with a V max of 28 nmol l -carnitine/g wet wt/h and had an apparent K m for perfusate carnitine of 33 μ m . At the normal serum levels of free carnitine (44 μ m ), about 85% of the myocardial carnitine uptake would be expected to occur via the saturable transport system. Serum carnitine decreased to a value well below the K m for transport in diabetic animals. It is concluded that a decreased rate of transport due to the lower serum carnitine may be responsible for the reduced levels of carnitine seen in diabetic hearts.
Anisotropy decays of indole, melittin monomer and melittin tetramer by frequency-domain fluorometry and multi-wavelength global analysis

We used frequency-domain fluorescence spectroscopy to measure the fluorescence lifetime and anisotropy decays of indole in propylene glycol, and of the tryptophan emission of melittin monomer and tetramer in water solutions at 5 °C. We obtained an increase in resolution of the anisotropy decays by using multiple excitation wavelengths, chosen to provide a range of fundamental anisotropy values. The multi-excitation wavelength anisotropy decays were analyzed globally to recover a single set of correlation times with wavelength-dependent anisotropy amplitudes. Simulated data and ϰR2 surfaces are shown to reveal the effect of multi-wavelength data on the resolution of complex anisotropy decays. For both indole and melittin, the anisotropy decays are heterogeneous and require two correlation times to fit the frequency-domain data. For indole in propylene glycol at 5°C we recovered correlation times of 0.59 and 4.10 ns, which appear to be characteristic of the rigid and asymmetric indole molecule. For melittin monomer the correlation times were 0.13 and 1.75 ns, and for melittin tetramer 0.12 and 3.96 ns. The shorter and longer correlation times of melittin are due to segmental motions and overall rotational diffusion of the polypeptide.