cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface chemistry of lipid raft and amyloid Aβ (1-40) Langmuir monolayer

Lipid rafts being rich in cholesterol and sphingolipids are considered to provide ordered lipid environment in the neuronal membranes, where it is hypothesized that the cleavage of amyloid precursor protein (APP) to Aβ (1-40) and Aβ (1-42) takes place. It is highly likely that the interaction of lipid raft components like cholesterol, sphingomylein or GM1 leads to nucleation of Aβ and results in aggregation or accumulation of amyloid plaques. One has investigated surface pressure-area isotherms of the lipid raft and Aβ (1-40) Langmuir monolayer. The compression-decompression cycles and the stability of the lipid raft Langmuir monolayer are crucial parameters for the investigation of interaction of Aβ (1-40) with the lipid raft Langmuir monolayer. It was revealed that GM1 provides instability to the lipid raft Langmuir monolayer. Adsorption of Aβ (1-40) onto the lipid raft Langmuir monolayer containing neutral (POPC) or negatively charged phospholipid (DPPG) was examined. The adsorption isotherms revealed that the concentration of cholesterol was important for adsorption of Aβ (1-40) onto the lipid raft Langmuir monolayer containing POPC whereas for the lipid raft Langmuir monolayer containing DPPG:cholesterol or GM1 did not play any role. In situ UV-vis absorption spectroscopy supported the interpretation of results for the adsorption isotherms.
Noninvasive functional photoacoustic tomography of blood-oxygen saturation in the brain

Since optical contrast is sensitive to functional parameters, including the hemoglobin oxygen saturation and the total concentration of hemoglobin, imaging based on optical contrast has been widely employed for the real-time monitoring of tissue oxygen consumption and hemodynamics in biological tissues. However, due to the overwhelming scattering of light in tissues, traditional optical imaging modalities cannot provide satisfactory spatial resolution. Functional photoacoustic tomography is a novel technique that combines high optical contrast and high ultrasonic resolution. Here, we present our study of a laser-based photoacoustic technique that, for the first time to our knowledge, monitors blood oxygenation in the rat brain in vivo. The cerebral blood oxygenation in the rat brain was imaged by photoacoustic detection at two wavelengths. The change in the hemoglobin oxygen saturation in the brain vessels as a result of the alternation from hyperoxia status to hypoxia status was visualized successfully with satisfactory spatial resolution. This work demonstrates that photoacoustic technique, based on the spectroscopic absorption of oxy- and deoxy-hemoglobin, can provide accurate functional imaging of cerebral blood oxygenation in the small-animal brain non-invasively with the skin and skull intact.
Duration of human MU opiate receptor blockade following naltrexone: Measurement by 11C-carfentanil pet

Background Naltrexone is a mu opiate receptor antagonist approved for the treatment of alcohol dependency. Previous reports have suggested a duration of receptor occupancy of naltrexone that greatly exceeds that predicted by it's 4 hour T1/2, or the 13 hour T1/2 of beta naltrexol, the predominant metabolite. We undertook a double blind, placebo controlled, randomized study of receptor occupancy using the highly selective mu opiate receptor ligand 11C-carfentanil. Methods Healthy volunteers underwent PET imaging with 11C-carfentanil at baseline, 3 24, 72 and 144 hours following a single dose of placebo, 12.5, 50 or 100mg of naltrexone. Regional analysis was undertaken using a statistical parametric mapping approach (SPM2). Results To date, 15 of 24 subjects have completed all phases of the study. At interim analysis, regions of significantly (p<0.001) lower activity were mapped in all known regions of brain mu receptors 3 and 24 hours following all doses of naltrexone. This effect was measurable at 72 hours for the combined 50/100mg dose. At 144 hours, significant blockade remained in the left temporal lobe. (see Table) Conclusions Our findings provide tomographic evidence of a persistence of blockade of the mu opiate receptor for up to 144 hours following naltrexone, with no evidence of a receptor level placebo effect. Correlation with plasma naltrexone and beta naltrexone is planned. Clinical Pharmacology & Therapeutics (2005) 77, P26–P26; doi: 10.1016/j.clpt.2004.11.099 Table 1. Placebo 12.5 mg 50/100 mg Baseline vs N = 6 N = 4 N = 5 3H NS P < 0.001 P < 0.001 24H NS P < 0.001 P < 0.001 72H NS NS P < 0.001 144H NS NS P < 0.01
Spatial and Temporal Variability of Phytoplankton and Zooplankton in Western Lake Erie

ABSTRACT We examined the plankton communities within western Lake Erie during the summers of 1995 and 1996 and evaluated the hypothesis that zebra mussels exert strong control over the abundance and spatial distribution of plankton. Phytoplankton and zooplankton biomass exhibited strong seasonal and spatial variability throughout the summers of 1995 and 1996. Nearshore areas generally contained more phytoplankton and zooplankton biomass than the offshore sampling area, but there was wide variability in pelagic phytoplankton and crustacean zooplankton. Zooplankton taxonomic composition was different between sampled areas, with more calanoid copepods compared to cladocerans and cyclopoid copepods found in deep, offshore stations. Such patterns increase the difficulty in understanding the effects of zebra mussels on western Lake Erie as they suggest that additional factors, such as nutrient availability, also affect the biomass of these pelagic communities.
EEG microstate analysis in human motor corrections

How human movement is controlled is still poorly understood, but numerous studies have suggested that the Central Nervous System (CNS) generates and controls continuous movement via discrete, elementary building blocks of movement or submovements. Most supporting evidence has come from kinematic studies, with investigation of neural correlates lacking. In this study we used microstate analysis to model building blocks of neuroelectrical activity recorded from high-density electroencephalography (64-channel EEG) from healthy subjects during a reaching task that required online movement corrections. Our goal was to provide a proof-of-principle demonstration of the promise of this method of coupling neural activity with movement recording and analysis. We found that each kinematic submovement was accompanied by a stereotyped set of microstates generated by the activity of a frontoparietal network. These results provide further evidence for the hypothesis that the CNS generates and controls continuous movement via discrete submovements. Applications include design of algorithms for robot-assisted neuro-rehabilitation and quantitative outcome metrics for motor disorders of neurological origin including stroke and Parkinson's disease.
Chemical defence in chewing and sucking insect herbivores: plant-derived cardenolides in the monarch butterfly and oleander aphid

Cardenolide sequestration by a hemimetabolous aphid and a holometabolous butterfly from the neotropical milkweed,Asclepias curassavica L., is compared. The oleander aphid,Aphis nerii B. de F., sequestered a similarly narrow range of cardenolide concentrations to the monarch butterfly,Danaus plexippus (L.), from the wide range of concentrations available in leaves of A.curassavica. However, A.nerii sequestered significantly less cardenolide (269 µg/0.1 g) thanD. plexippus (528 µg/0.1 g). The honeydew excreted by A.nerii was comprised of 46% cardenolide. The complete polarity range of 25 cardenolides detected by thin layer chromatography in A.curassavica was represented in the 17 whole aphid cardenolides and the 20 aphid honeydew cardenolides detected. D.plexippus sequestered a narrower polarity range of 11 cardenolides, having eliminated low polarity cardenolide genins and glycosides. It is suggested that these chemical differences may be related to interactions among the broad feeding tactics of sucking or chewing milkweed leaves, life history constraints of holometabolyversus hemimetaboly, the distribution of milkweed food resources in space and time, and the dynamics of natural enemies.
A manned air-to-air combat simulator.

This paper discusses the development of a simulator which utilizes two cockpits equipped with individual instruments, controls and visual displays. The objective is to provide a new means of evaluating airplane capabilities in air-to-air combat. Either pilot can maneuver, within his airplane's flight envelope, against the opposing airplane. All computation is by digital computer. A collimated display for each cockpit presents the opposing airplane, the gunsight and the earth. The images are "stroke written" by a Schmidt cathode-ray tube projector. An 80° field-of-view limitation is circumvented by presenting a mirror view when the opposing airplane is in a chase position and a "radarlike" synthetic display when it is not within the forward or aft 80° cone. Future developments will display the opposing airplanes' positions on the inside of spheres enclosing each cockpit.
Shock-induced and self-propagating high-temperature synthesis reactions in two powder mixtures: 5:3 Atomic ratio Ti/Si and 1:1 Atomic ratio Ni/Si

The conditions for initiation and propagation of the reaction forming the intermetallic compounds Ti5Si3 and NiSi from mixtures of elemental powders of varying porosity have been investigated using shock waves of different pressure and at atmospheric pressure using hot wire ignition in air and in an argon atmosphere. In each case, the reaction either went to completion or the powder remained essentially unreacted. The conditions for the initiation of the reaction in Ti/Si are sensitive to the presence of air. Two regimes of porosity and shock pressure are found for the Ti/Si mixture which cause complete reaction. A low-energy regime with a high initial porosity (producing a low shock pressure) with 0.1 torr of residual air triggers the reaction, while no reaction is observed with a 128 pct higher shock energy and a lower initial porosity (producing a higher shock pressure) when the residual air is replaced with argon. Hot wire ignition of porous Ti/Si powder at room temperature initiates a self-propagating high-temperature synthesis (SHS) reaction more easily in air than in an argon atmosphere, while the Ni/Si powder must be heated to allow the SHS reaction to propagate in high- or low-porosity mixtures in air. These observations are compared to published work on self-sustaining reactions in multilayer films. Reasons for the difference in behavior of the two powder mixtures are discussed.
Recent Advances In The Single-Gun Color Television Light-Valve Projector

This new color television light-valve projector consists of a deformable fluid control layer and electron gun in a sealed vacuum tube, an external light source and projection lens. It is being used for large screen color television applications such as simulation, entertainment, and control centers. Continued development of this type of light-valve projector has resulted in improvements in resolu-tion, sealed light-valve life, higher TV line standards, and higher brightness. Resolution gains in both color and black and white are due to refined optics and in applying new concepts for the "grating" modulators. The life of the sealed light valve has been extended to over 6500 hours by improvements in the cathode, ion pump and fluid. Operation at the 1029 TV line standards has been achieved for the monochrome light valve and prospects look good for pushing the single gun color projector to the same limit. Recent experiments have shown the feasibility of creating a "wide screen" format for either color or monochrome by the addition of an anamorphic lens and supplying the projector with a "squeezed" format picture signal. Applications of these projectors to simulation and other fields will be discussed.
Influence of Size and Shape Properties of Railroad Ballast on Aggregate Packing: Statistical Analysis

Railroad ballast is uniformly graded coarse aggregate placed between and immediately underneath the ties to provide drainage and structural support for the loading applied by trains. In the United States, several ballast gradation recommendations are suggested by the American Railway Engineering and Maintenance-of-Way Association (AREMA). Most of these recommended uniform gradations have somewhat wide ranges at their control sieves; this range often creates significantly different grain-size distributions within the same gradation band. In this analysis, AREMA No. 24 gradation was studied for controlled changes in grain-size distributions within its band. Gradations were created by using three control sieves within the AREMA No. 24 gradation band. In addition, to emphasize the significance of particle shape, three sets of particles having high-, medium-, and low-angularity indexes quantified by image analysis were also considered in the packing simulations carried out with an image-aided ballast aggregate...
Lateral tegmental field neurons sensitive to muscular contraction: A role in pressor reflexes?

The medullary lateral tegmental field (LTF) has a major role in sympathetic nerve discharge (SND) rhythmicity, but its role in pressor reflexes generated by hindlimb muscular contraction (MC) is unknown. Therefore, two sets of experiments were performed in 17 chloralose-urethane anesthetized cats. First, responses of single LTF neurons to MC induced by L7-S1 ventral root stimulation were examined. The majority (30 of 47) of LTF neurons increased firing during MC. Most LTF neurons had a basal discharge correlated with the 2-10 Hz rhythm of SND or the cardiac cycle and responded to increases in blood pressure. Only seven neurons were inhibited by MC, most having a respiratory rhythm. Second, pressor responses to MC and to caudal hypothalamic stimulation were examined before and after bilateral LTF microinjections of a synaptic blocker (CoCl2) as well as with lidocaine. Microinjection of CoCl2 or lidocaine significantly attenuating the dominant 2-10 Hz power coefficient of SND had no effect on the pressor responses to MC or caudal hypothalamic stimulation. Therefore, LTF may be important for basal rhythms in SND and may help synchronize SND during MC, but its contribution to basal rhythms is apparently not required for pressor reflexes evoked by hindlimb MC or hypothalamic stimulation.
Structural basis for bitterness based on Rabdosia diterpenes.

Abstract Bitterness of naturally occurring substances seems to be due to a balance between the “bitter unit” and the hydrophobic portions of the molecule. The study based on the Rabdosia diterpenes indicates that the bitter unit consists of a proton donor DH group and a proton acceptor A group. In addition to this DH-A unit, and A-A unit may also be possible. The bitter compounds could enter the molecular structure of the receptor site with the bitter unit oriented into the aqueous phase by hydrogen bonding and the hydrophobic portion aligned into the lipid phase by dispersion forces.
Determination of a dynamic grinding model

In precision abrasive machining, it is important to control process variables such as the material removal rate, normal force and power input, as these factors influence surface finish, dimensional precision, and material damage. In this research, a linear grinding process model, with enhancements over past models, is developed relating normal force to material removal rates. Two experimental procedures for the determination of the grinding model's parameters are presented. Simulations are performed to validate the grinding model. The determined model is found to be a valid representation of the grinding process that should prove useful in adaptive control with real-time parameter estimation.
On the evaluation of the true phase of interferograms

An iterative technique that uses sine and cosine modulations along with low-pass filtering to extract the true phase values of a carrier frequency interferogram is proposed in this paper. An illustrative example is given in which this technique is applied. Results generated from the application of this technique are compared with exact phase values, and excellent agreement between the exact and computed phase values is demonstrated. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 40–43, 2002.
Dopamine-containing amacrine cells of rhesus monkey retina parallel rods in spatial distribution

Dopamine-containing amacrine cells of rhesus monkey were found everywhere outside of the foveola in whole, flat retinas by the formaldehyde-glutaraldehyde fluorescent method. There were about 7500 such cells in a single retina and their density, determined by cell counts and measured by a nearest neighbor method, was minimal in foveal and peripheral regions and maximal at 3 mm from the center of the fovea. Compared to density distributions of other retinal neuron types, dopamine-containing amacrine cells correlated only with rods, which also had a peak density at 3 mm eccentricity. Cones and ganglion cells peaked in the foveal pit, or within 1 mm of it, respectively. As the distribution of dopamine-containing cells followed that of rods, it is suggested that dopamine could be involved in the rod neuronal circuitry of primates.
Correlation of scanning electron microscope and light microscope images of individual cells in human blood and blood clots

Abstract Blood and bone marrow were examined with conventional light microscopy techniques of staining. The same preparations were then also examined in the scanning electron microscope. The individual cells photographed in the light microscope were imaged in the scanning electron microscope using the secondary electron mode. The surface features revealed in the scanning electron micrographs were found to be distinctive for the different types of leukocytes identified by conventional light microscopy staining methods. The microarchitecture of human whole blood clots as imaged with the scanning electron microscope is also presented.
Crashworthiness assessment of a paratransit bus

Abstract Most of the bus safety standards in the USA are not applicable to cutaway buses for which a production process is split into two stages. First, the chassis and cab section are assembled by automobile manufactures. Then the vehicle is shipped to another company, where bus body and additional equipment are installed. Lack of strict structural standards for transit bus body builders stimulates the need for crashworthiness and safety evaluation for this category of vehicles. This study focused on a selected transit bus, the Ford Eldorado Aerotech 240. Due to the lack of design data the reverse engineering process was used to acquire the geometric data of the bus. The finite element (FE) model was developed based on the geometry obtained by disassembling and digitizing all major parts of the actual bus. The FE model consists of 73,600 finite elements, has 174 defined properties (groups of elements with the same features) and 23 material models. LS-DYNA non-linear, explicit, 3-D, dynamic FE computer code was used to simulate behavior of the FE model under different impact scenarios, such as front impact and side impact of two buses at various velocities.
Peripheral CD4 loss of regulatory T cells is associated with persistent viraemia in chronic HIV infection

Chronic HIV infection is associated with T cell abnormalities and altered effector function. Regulatory T cells (Treg) are CD4+ T cells that play a critical role in regulating the immune system. The impact of regulatory T cells on HIV infection and disease progression may be highly significant. We hypothesize that chronic antigenic stimulation from a persistent, high viraemic state may promote a population of Treg that contributes to HIV-associated immune dysfunction. We evaluated the pattern of Treg in chronically infected, HIV-positive individuals over a course of 6 months. Treg are depleted at a distinct rate from that of absolute CD4 cells and loss of Treg is slower in the presence of viral suppression. In vitro depletion of CD25+ CD4+ cells resulted in increased Gag-specific CD4 and CD8 responses. A significant correlation between ex vivo measurement of Treg and Gag-specific CD4 T cell responses was observed (r=-0 x 41, P=0 x 018) with a trend observed with Gag-specific CD8 T cell responses (P=0 x 07). The impact of HIV infection on the Treg population directly complicates the measured effect of Treg on the immune dysfunction although our data support the important role of Treg on modulating the effector T cell response in chronic infection.
Communicating in Complex Situations: A Normative Approach to HIV-Related Talk Among Parents Who Are HIV+

Parents with HIV/AIDS are confronted with unique challenges when discussing HIV-related information with their children. Strategies for navigating these challenges effectively have not been systematically examined. In this study, we conducted in-depth interviews with 76 parents with HIV/AIDS who had children ages 10-18 years. Guided by O'Keefe and Delia's definition of a complex communication situation and Goldsmith's normative approach to interpersonal communication, we examined parents' goals for discussing HIV-related information, factors that made conversations challenging, and instances where these conversational purposes conflicted with one another. Our data reveal the following parent-adolescent communication predicaments: relaying safety information about HIV while minimizing child anxiety, modeling open family communication without damaging one's parental identity, and balancing parent-child relational needs amid living with an unpredictable health condition. Parents also described a variety of strategies for mitigating challenges when discussing HIV-related topics. Strategies parents perceived as effective included reframing HIV as a chronic, manageable illness; keeping talk educational; and embedding HIV-related topics within more general conversations. The theoretical and practical applications of these findings are discussed with regard to their relevance to health communication scholars and HIV care professionals.
Effects of maternal alcohol consumption on milk and blood lymphocytes and IgG antibody levels from Trichinella spiralis-infected rats.

Immunity to the intestinal parasite Trichinella spiralis can be transferred from the mother to the neonate during lactation. Previous studies in our laboratory showed that the passage of immunity to pups from ethanol-treated dams was depressed. This study examined the effect of ethanol consumption during pregnancy and lactation on the T. spiralis-associated immune components in milk and blood. Groups of female rats were fed either ethanol-containing or isocaloric liquid diets for 30 days before T. spiralis infection, mated and maintained on corresponding diets through pregnancy and lactation. Two-color flow cytometric analysis was performed for lymphocyte populations, enzyme-linked immunoabsorbent assay for specific IgG, and radial immunodiffusion assay for total IgG. The percentage of total T cells and their subsets, T helper cells and T cytotoxic/suppressor cells in milk and those in blood were similar between pair-fed and ethanol-treated animals. However, the percentage of natural killer cells in milk from ethanol animals was significantly reduced compared with the pair-fed group (33% vs. 54%). The percentage of activated or memory type T helper cell subset (OX22−W3/25+) was significantly increased in the blood of the ethanol-treated group. Pair-fed animals showed higher T. spiralis-specific IgG antibody levels both in milk and blood compared with ethanol-treated animals. In ethanol-treated animals, specific IgG levels and total IgG concentration in milk were significantly lower than those in blood, whereas in pair-fed animals, only total IgG concentration in milk was lower than that in blood. This study indicates that ethanol consumption during pregnancy and lactation alters the maternal immune system. Decreased milk natural killer cells and depressed specific antibody levels in milk of ethanol-treated animals are possible contributing factors to the previously observed depressed lactational immune transfer to the pups.
Relative Standing: A Framework for Understanding Departures of Acquired Executives

Prior attempts to explain the departure rates of the executives of acquired firms, primarily through strategic and economic logics, have yielded limited results. This study drew on the concept of r...
Lymphocyte responsiveness to acetylcholine receptor in rats with experimental autoimmune myasthenia gravis

We examined the time course of lymphocyte responsiveness to acetylcholine receptor (AChR) in rats with experimental autoimmune myasthenia gravis (EAMG). Rats were immunized with purified torpedo AChR. At intervals of one to eight weeks later, lymphocytes from the lymph nodes and spleen were cultured with purified torpedo AChR and rat muscle extract containing AChR. Lymphocyte responsiveness (stimulation index) was determined from uptake of 3H-labeled thymidine by the cultured cells. The response of lymphocytes to torpedo antigen began earlier and rose more rapidly than that to the homologous (rat) antigen. Lymph node cells responded more promptly than spleen lymphocytes. The stimulation indexes peaked at four to six weeks while antibodies to both antigens continued to rise. Delineation of this pattern of lymphocyte responsiveness sheds further light on the pathogenesis of the autoimmune response in EAMG and will be useful in the future design of immunotherapeutic strategies.
Effects of a Norethynodrel-Mestranol Combination (Enovid) on Hypothalamic and Pituitary Hormones in Rats1

The effects of a norethynodrelmestranol combination (Enovid) were determined on the hypothalamic content of luteinizing hormone-releasing factor (LRF), follicle stimulating hormone-releasing factor (FSH-RF) and prolactin inhibiting factor (PIF) in mature female rats. Its effects were also obseived on pituitary concentration of LH, FSH and prolactin, and on the ovaries, mammary glands and other tissues. Enovid injected subcutaneously once daily at a dose of 200 μg/100 g body weight for 20 days resulted in decreased pituitary FSH and LH and increased prolactin concentration. In vitro assays of neutralized acid extracts of hypothalamus from Enovid-injected rats revealed that it significantly decreased FSH-RF, LRF and PIF content when compared with controlcontrol rats. The ovaries of Enovid-injected rats were smaller than in control rats, follicular development was inhibited, and large corpora lutea were present despite indications that ovulation was inhibited. Enovid also stimulated extensive lobulo-alveolar...
Terms of endearment: engaging students in the digital age

Purpose – This article seeks to describe the challenge of providing impactful research assistance to college students.Design/methodology/approach – The article discusses student perceptions of librarians, and the lack of awareness students have about the reference and research support provided by librarians.Findings – The article suggests alternative approaches to engaging students may break down barriers, but are no replacement for individual consultation.Originality/value – The article provides thoughts around retention of librarian approachability in the digital age.
YBa2Cu3O7−δ films: Calculation of the thermal conductivity and phonon mean‐free path

We estimate the phonon mean‐free path (mfp) in YBa2Cu3O7−δ by performing a theoretical fitting procedure on bulk single‐crystal data. This analysis indicates that the mfps of the phonons that are most responsible for the transport of heat are much longer than would be predicted from kinetic theory. These values are incorporated into a recently proposed treatment of the size effect to provide an estimate of the thermal conductivity of YBa2Cu3O7−δ films.
Apical control of branch movements in white pine: Compression wood action

The movements of branches or control stem girdled white pine (Pinus strobus L.) were analyzed using beam theory. The stresses generated in the compression wood (CW) produced bending moments to counter the added bending moments due to new branch growth. The branches on the treated trees produced additional CW after untreated trees stopped elongation and diameter growth. The intensity of the stresses in this additional CW was greater than in the other CW. Thus, branches on treated trees moved up vertically well beyond their initial orientation due to both more CW and more active CW. The branches on untreated trees all deflected downward as branch weight continued to increase after CW production stopped.
Stereospecific high-performance liquid chromatographic validation of homoeriodictyol in serum and Yerba Santa (Eriodictyon glutinosum).

Abstract A stereospecific method of analysis of racemic homoeriodictyol (eriodictyol 3′-methyl ether) in biological fluids is necessary to study pharmacokinetics and disposition in fruits and herbs. A simple high-performance liquid chromatographic method was developed for the determination of homoeriodictyol enantiomers. Separation was achieved in a Chiralcel ® OJ-RH column with UV-detection at 288 nm. The standard curves in serum were linear ranging from 0.5 to 100.0 μg/ml for each enantiomer. The mean extraction efficiency was >88.0%. Precision of the assay was Eriodictyon glutinosum ).
Bose-Einstein condensation in dilute atomic gases and the realization of an atom laser

We summarize all experimental studies of Bose-Einstein condensation in dilute atomic gases reported thus far and discuss the experimental techniques used to produce, manipulate and observe nanokelvin samples of atoms.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
On the importance of the thermosiphon effect in CPG (CO2 plume geothermal) power systems

Abstract CPG (CO2 Plume Geothermal) energy systems use CO2 to extract thermal energy from naturally permeable geologic formations at depth. CO2 has advantages over brine: high mobility, low solubility of amorphous silica, and higher density sensitivity to temperature. The density of CO2 changes substantially between geothermal reservoir and surface plant, resulting in a buoyancy-driven convective current – a thermosiphon – that reduces or eliminates pumping requirements. We estimated and compared the strength of this thermosiphon for CO2 and for 20 weight percent NaCl brine for reservoir depths up to 5 km and geothermal gradients of 20, 35, and 50 °C/km. We found that through the reservoir, CO2 has a pressure drop approximately 3–12 times less than brine at the same mass flowrate, making the CO2 thermosiphon sufficient to produce power using reservoirs as shallow as 0.5 km. At 2.5 km depth with a 35 °C/km gradient – the approximate western U.S. continental mean – the CO2 thermosiphon converted approximately 10% of the energy extracted from the reservoir to fluid circulation, compared to less than 1% with brine, where additional mechanical pumping is necessary. We found CO2 is a particularly advantageous working fluid at depths between 0.5 km and 3 km.
Transient force generation during impulsive rotation of wall-mounted panels

Square and triangular shape actuator panels mounted on the wall of a wind tunnel beneath an air flow have been impulsively rotated with an angular velocity between 3 and . A custom-designed balance was used to measure the time-dependent lift and drag forces during the deployment of the actuator, the position of which was monitored by a digital encoder. The measured forces have been compensated for inertia effects which are significant. The results indicated that all lift and drag force coefficients during the transient deployment are different than the corresponding coefficients under stationary conditions at the same deployment angle. It was found that these dynamic effects are augmented with increasing velocity ratio . The square actuator was found to have better aerodynamic performance than the triangular ones. Additional experiments within different boundary layers reveal that the generated unsteady forces on the moving panels are affected by the characteristics of the incoming boundary layers. The results showed that the thinner the boundary layer is the higher the forces are. Time-resolved flow visualization studies indicated that during the deployment of the panel the upstream turbulent boundary layer structures and the free stream fluid are decelerated and squeezed in the longitudinal direction as they approach the moving plate. A very thin and highly sheared wall layer develops over the moving panel, it generates a substantial amount of vorticity and it subsequently separates from the three edges of the panel to form a large-scale ring-like vortical structure which is responsible for the transient augmentation of the aerodynamic forces. This structure consists of wrapped around separated shear layers which contain pockets of compressed eddies and free stream fluid originated in the upstream incoming boundary layer and free stream. A horseshoe vortex starts to form over the moving plate and during the final stages of deployment it has been moved upstream while the incoming boundary layer turbulent structures are pushed and diverted upwards.
Numerical evaluation of the Feynman integral-over-paths in real and imaginary-time

Abstract New techniques are described for Monte Carlo evaluation of the propagation of quantum mechanical systems in both real and imaginary-time using the Feynman integral-over-paths formulation of quantum mechanics. For imaginary-time calculations path translation is used to augment the technique of Lawande et. al. This simple-yet-powerful technique allows the equilibrium probability density to be accurately evaluated in the presence of multiple potential wells. It is shown that path translation permits the calculation of the unknown ground-state energy of one confining potential by comparison with the known ground-state energy of another. A double finite-square-well potential and a finite-square-well/parabolic-well pair are presented as examples. For real-time calculations, a weighted analytical averaging of the exponential in the classical action is performed over a region of paths. This “windowed action” has both real and imaginary components. The imaginary component yields an exponentially decaying probability for selecting paths, thereby providing a basis for the Monte Carlo evaluation of the real-time integral-over-paths. Examples of a wave-packet in a parabolic well and a wave-packet impinging upon a potential barrier are considered.
Electron Microscopic Evidence of Alternating the Perilacunar Walls of Aging Osteocytic-Osteoclastic and Osteoplastic Activity in Mice

Electron micropscopic observations of cortical and trabecular bone of mice 5 to 104 weeks of age revealed numerous lacunae bearing structural perilacunar evidence of osteocytic-osteoclastic and osteoplastic activity. Concavescalloping of perilacunar walls was interpreted as indicative of osteocytic-osteoclasis while convex-scalloping of surfaces of osteoplasis. Although these processes were commonly observed at the lacunar walls, concave-scalloping was not limited exclusively to these structures since on occasion it was also observed at the pericanalicular walls. With increasing age, more lacunae were involved. This involvement extended to near surface osteocytes in old animals. The lacunae of older mice revealed evidence of repeated, sometimes alternate, phases of osteocytic-osteoclasis and osteoplasis, each delineated by the presence of an osmiophilic lamina. The osmiophilic laminae reflect where these activities last occurred. It was concluded from ultrastructural observations that these alternating pr...
Dual Regulation of Insulin-Like Growth Factor Binding Protein-1 Levels by Insulin and Cortisol during Fasting

Insulin-like growth factor (IGF) binding protein-1 (IGFBP-1) gene transcription is known to be inhibited by insulin in vivo and in vitro. Levels of IGFBP-1 typically rise during fasting but also rise after acute hypoglycemia, including that induced by insulin, through an unknown mechanism that may involve counterregulatory hormones such as cortisol. To study the regulation of IGFBP-1 secretion during fasting, we measured IGFBP-1, insulin, cortisol, GH, and glucose during the course of standardized fasting studies in a total of 21 children. The fasting studies lasted 13-32 h and were terminated for a whole-blood glucose concentration of less than 50 mg/dL (2.8 mmol). Of the children studied, 9 children had no disorder, 8 had ketotic hypoglycemia, 2 had isolated GH deficiency, and 2 had fatty acid oxidation disorders. During fasting, IGFBP-1 rose above the mean baseline levels of 28+/-5 ng/mL to a mean level+/-SEM of 336+/-59 ng/mL at the time of hypoglycemia (P=0.001). IGFBP-1 was strongly associated with serum insulin and cortisol levels over the entire course of fasting (P < 0.0001)). The interaction of the 2 hormones across time was also strongly significant (P < 0.0001). There was no statistically significant association between IGFBP-1 and GH or glucose. At the time of hypoglycemia, insulin levels were suppressed to 1.7 microU/mL or less, and there was no correlation between IGFBP-1 levels at the end of fasting and final insulin level. In contrast, cortisol levels correlated with IGFBP-1 in the final hypoglycemic sample (r=0.56, P < 0.01). Partial correlation analysis revealed that the relationship between IGFBP-1 and cortisol was unchanged when the data was controlled for insulin levels. These data show that insulin and cortisol both regulate IGFBP-1 secretion during fasting; the effects of insulin and cortisol are strong during the course of fasting. Significant hypoglycemia stimulates a further rise in IGFBP-1, which seems to be regulated, in part, by cortisol. The cortisol-induced rise in IGFBP-1 during fasting and during hypoglycemia potentially serves to prevent the hypoglycemic effects of free IGFs.
Association between markers of the metabolic syndrome and lower urinary tract symptoms in the Third National Health and Nutrition Examination Survey (NHANES III)

Association between markers of the metabolic syndrome and lower urinary tract symptoms in the Third National Health and Nutrition Examination Survey (NHANES III)
Understanding Errors in Approximate Distributed Latent Dirichlet Allocation

Latent Dirichlet allocation (LDA) is a popular algorithm for discovering semantic structure in large collections of text or other data. Although its complexity is linear in the data size, its use on increasingly massive collections has created considerable interest in parallel implementations. “Approximate distributed” LDA, or AD-LDA, approximates the popular collapsed Gibbs sampling algorithm for LDA models while running on a distributed architecture. Although this algorithm often appears to perform well in practice, its quality is not well understood theoretically or easily assessed on new data. In this work, we theoretically justify the approximation, and modify AD-LDA to track an error bound on performance. Specifically, we upper bound the probability of making a sampling error at each step of the algorithm (compared to an exact, sequential Gibbs sampler), given the samples drawn thus far. We show empirically that our bound is sufficiently tight to give a meaningful and intuitive measure of approximation error in AD-LDA, allowing the user to track the tradeoff between accuracy and efficiency while executing in parallel.
Childhood pleuropulmonary blastoma: Caution against nonoperative management of congenital lung cysts

Pulmonary blastoma is a rare and aggressive malignant tumor that affects children and adults. Recently a 3-year-old boy with a 2-year history of bilateral unilocular pulmonary cysts was transferred for evaluation of a cough and high spiking fever. A chest radiogram showed left pulmonary consolidation with pleural effusion, but thoracentesis was unsuccessful. Computerized tomography (CT) was suggestive of a pulmonary abscess, but CT-guided drainage did not yield any purulent fluid. Percutaneous biopsies were performed, and the cytology showed malignant cells. During thoracotomy, a large tumor involving the left lower lobe and pleural space was found, and a biopsy was performed. A frozen section showed blastemal and mesenchymal components devoid of neoplastic epithelium, consistent with the pleural variant of pulmonary blastoma. A left lower lobectomy, with tumor decortication of the pleural space, achieved total gross tumor removal. The child received aggressive multiagent chemotherapy, and midway through it he underwent elective excision of the opposite lung cyst. It has been 17 months since the lobectomy; he is off chemotherapy and has no evidence of disease. A review of the literature showed that a large number of pediatric pulmonary blastomas are associated with cystic lung disease. Because total tumor removal offers the only chance of a good long-term outcome, surgical excision or close follow-up of pulmonary cysts in children is strongly recommended.
Image transform coding using trellis-coded quatization through noisy channels

We propose a joint source/channel coding scheme to transmit image through binary noisy channels based on 2-D discrete cosine transform (DCT) and trellis coded quantization (TCQ). When an image is transmitted through noisy channel with high throughput, both image compression and error-resilient coding scheme need to be considered. After the discrete cosine transform, the source image is decomposed into several subsources according to the transform coefficient positions, i.e., the same frequency coefficients in different DCT blocks are grouped together as a single subsource. The mean and variance values are used to construct the scalar codebooks for TCQ. Uniform threshold trellis coded quantizer is constructed to release the complexity and the transform coefficients are quantized by these fixed-rate quantizer and transmitted through noisy channels. No explicit error protection is used. The steepest descent method and iterative schemes are employed to determine the optimum bit allocation among the subsources subject to the constraints of the average coding rate and allowable maximum bits to each sample. Neighborhood relation is employed to limit the searching space when a bit is to be allocated to certain subsource. Simulation results show that the performance is very promising.
Induced heterologous exchange at meiosis in Drosophila. I. Exchanges between Y and fourth chromosomes.

Abstract Break points have been mapped for a group of 51 Y chromosome fragments induced in irradiated Drosophila melanogaster females. Fragments arising by exchange with the right arm of chromosome 4(4R) have the breakages clustered in the long arm of the Y (Y L ) proximal to the most distal male-fertility locus, and proximal to the cubitus interruptus locus in 4R. Fragments arising by other exchanges have the breakages clustered toward the ends of the Y, usually distal to the most distal male-fertility loci of either arm of the Y. It is suggested that specific, relatively short regions are regularly associated to form “sites” within which the induction of exchange is possible.
Fabrication of SOI CMOS over large-area continuous-oxide films formed using epitaxial lateral overgrowth techniques

The authors have developed techniques for producing thin, monocrystalline silicon films over large area continuous oxides using the epitaxial lateral overgrowth (ELO) approach and have investigated the electrical characteristics of CMOS devices fabricated in these films. A conventional ELO process using a growth-etchback technique to eliminate spurious nucleation was used to overgrow single-crystal silicon from seed regions over the oxide stripes. Silicon nitride was deposited and patterned with a mask which had an identical pattern to the first mask. After nitride etch, the original seed region was exposed. A partial silicon etch was performed and the wafers were then reoxidized. During this step an oxide was grown over the exposed seed region which subsequently coalesced with the initial oxide stripes, forming a continuous insulating region covered by stripes of single-crystal silicon. These formed the seed for a second ELO step that resulted in a continuous single-crystal silicon film over the underlying oxide. The transistors, fabricated in ELO material, exhibited electrical characteristics comparable to both SOS controls and to devices fabricated on SIMOX (silicon implanted with oxygen) wafers in the laboratory using an identical process. >
Genes regulating dendritic outgrowth, branching, and routing in Drosophila

Signaling between neurons requires highly specialized subcellular structures, including dendrites and axons. Dendrites exhibit diverse morphologies yet little is known about the mechanisms controlling dendrite formation in vivo. We have developed methods to visualize the stereotyped dendritic morphogenesis in living Drosophila embryos. Dendrite development is altered in prospero mutants and in transgenic embryos expressing a constitutively active form of the small GTPase cdc42. From a genetic screen, we have identified several genes that control different aspects of dendrite development including dendritic outgrowth, branching, and routing. These genes include kakapo, a large cytoskeletal protein related to plectin and dystrophin; flamingo, a seven-transmembrane protein containing cadherin-like repeats; enabled, a substrate of the tyrosine kinase Abl; and nine potentially novel loci. These findings begin to reveal the molecular mechanisms controlling dendritic morphogenesis.
Realization of Boolean functions by perceptron algorithm

Summary form only given. A two-step design procedure is proposed so that any Boolean function can be realized by the reliable perceptron algorithm. The first step is the learning phase. In the second step, the outputs are simply connected to an OR-gate, a perceptron by itself. >
Discrete optimization using decision-directed learning for distributed networked computing

Decision-directed learning (DDL) is an iterative discrete approach to finding a feasible solution for large-scale combinatorial optimization problems. DDL is capable of efficiently formulating a solution to network scheduling problems that involve load limiting device utilization, selecting parallel configurations for software applications and host hardware using a minimum set of resources, and meeting time-to-result performance requirements in a dynamic network environment. The paper quantifies the algorithms that constitute DDL and compares its performance to other popular combinatorial optimization techniques. This is done within the context of self-directed real-time networked resource configuration for dynamically building a mission specific signal-processor for real-time distributed and parallel applications.
Targeting Wild-Type and Mutationally Activated FGFR4 in Rhabdomyosarcoma with the Inhibitor Ponatinib (AP24534)

Rhabdomyosarcoma (RMS) is the most common childhood soft tissue sarcoma. Despite advances in modern therapy, patients with relapsed or metastatic disease have a very poor clinical prognosis. Fibroblast Growth Factor Receptor 4 (FGFR4) is a cell surface tyrosine kinase receptor that is involved in normal myogenesis and muscle regeneration, but not commonly expressed in differentiated muscle tissues. Amplification and mutational activation of FGFR4 has been reported in RMS and promotes tumor progression. Therefore, FGFR4 is a tractable therapeutic target for patients with RMS. In this study, we used a chimeric Ba/F3 TEL-FGFR4 construct to test five tyrosine kinase inhibitors reported to specifically inhibit FGFRs in the nanomolar range. We found ponatinib (AP24534) to be the most potent FGFR4 inhibitor with an IC50 in the nanomolar range. Ponatinib inhibited the growth of RMS cells expressing wild-type or mutated FGFR4 through increased apoptosis. Phosphorylation of wild-type and mutated FGFR4 as well as its downstream target STAT3 was also suppressed by ponatinib. Finally, ponatinib treatment inhibited tumor growth in a RMS mouse model expressing mutated FGFR4. Therefore, our data suggests that ponatinib is a potentially effective therapeutic agent for RMS tumors that are driven by a dysregulated FGFR4 signaling pathway.