cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of ingested mannoheptulose in animals and man.

Abstract The intestinal absorption, blood levels, and urinary excretion of D-manno-heptulose, a 7-carbon keto sugar, was studied in rats, dogs, monkeys and man. Intestinal absorption was clearly demonstrated in all four species, and blood levels and urinary excretion were shown to be related to ingested dose. There was a depression of plasma insulin and the insulogenic index following the administration of mannoheptulose. These findings suggest that MH should be utilized for further studies of the control mechanisms of insulin secretion, and as a potential, oral, therapeutic agent in the treatment of chronic or recurrent hypoglycemia due to hyperinsulinism.
Different involuntary mechanisms underlie priming and LOP effects in stem completion tests

The role of intentional retrieval, involuntary conscious memory, and lexical processing in priming and levels‐of‐processing (LOP) effects in stem completion tests was investigated in three experiments. First, Experiment 1 provided strong evidence against the intentional retrieval hypothesis for the implicit LOP effects. LOP effects in the explicit test were dependent on intertrial interval at test, whereas LOP effects in the implicit test were not. Second, support was provided for the involuntary conscious memory hypothesis. Implicit memory (priming) was associated with awareness in all three experiments and the implicit LOP effect was associated with awareness in two of the three experiments. Third, it was concluded that lexical processing per se played a limited role in both priming and implicit LOP effects. Although priming was sensitive to normative rates of production in Experiment 1 and the number of solutions in all three experiments, it was insensitive to frequency manipulations. The LOP effect wa...
Determination of tryptophan and several of its metabolites in physiological samples by reversed-phase liquid chromatography with electrochemical detection

A new method for the concurrent assay of three tryptophan metabolites at the picomole level is described. The method has been developed for blood, urine, cerebrospinal fluid, and tissue samples such as whole brain, brain parts, and endocrine glands. Tryptophan itself, serotonin, and 5-hydroxyindoleacetic acid are isolated initially on extraction columns, eluted with a suitable solvent, and injected onto a liquid chromatograph with an amperometric detector. This general approach may be applicable to a variety of other tryptophan metabolites and should be useful in both research and clinical investigations.
AND NEVER THE TWO SHALL MEET?: STUDENT VS. FACULTY PERCEPTIONS OF ONLINE COURSES

The education literature is blossoming with work on perceptions of distance education, online teaching, hybrid courses, and the like. Although this literature is important for helping faculty to understand the costs and benefits for teaching in these newer formats, little attention has been paid to documenting potential differences between student expectations for taking and faculty perceptions about teaching online courses. The current project gathered perceptual data from students and faculty about online courses. Findings suggest that differences between student and faculty perceptions of online courses might create barriers that diminish the effectiveness of the teaching-learning environment in such courses.
Fiddler crab–vegetation interactions in hypersaline habitats

Abiotic conditions often change ecological interactions. Studies in areas with low to moderate soil salinities have demonstrated a facultative mutualism between fiddler crabs and salt marsh vegetation. In these habitats, fiddler crab burrowing increases plant growth, and plant roots help support the walls of crab burrows. We looked for these interactions in hypersaline soils bordering unvegetated salt pans in a Georgia salt marsh. Crab burrows and vegetation cover were positively associated. Neither crab removals nor burrow additions demonstrated a positive effect of crabs on vegetation. However, both vegetation removals and the addition of an artificial canopy (suspended shadecloth) demonstrated a strong positive effect of vegetation on crab burrows. In contrast to previous studies, we found no evidence that plants supported burrow walls. Instead, crabs likely associate with vegetation to avoid predators. Our results caution against extrapolating experimental results between habitats with different abiotic conditions.
Physics Of High Resolution Sodium MRI Of The Brain

While proton imaging has become a routine diagnostic modality, sodium imaging has been difficult to obtain because of its inherent weakness in signal strength due to significantly lower concentration in tissue. -This difficulty of poor signal to noise ratio can be over-come in several ways, by using 3 dimensional data acquisition rather than 2 dimensional, a better low-noise electronics and fast pulse repetition rate for more signal averaging and multi-echo acquisition. The biochemical properties of sodium, yielding a dramatic contrast changes associated with pathology, also lead to facilitate favorable conditions for clinical imaging compared with proton imaging. The combined use of the advanced imaging techniques and the biochemical properties of sodium can produce clinically useful images. We have demonstrated an additional use of sodium imaging by obtaining simultaneous images of proton and sodium for direct comparison of the two distinctly different but related modalities.
Hybrid magnetic nanoparticles derived from wüstite disproportionation reactions at the nanoscale

We present Mossbauer studies of hybrid iron-oxide nanoparticles obtained by the disproportionation of oleic acid stabilized wustite (FexO) nanoparticles produced by selective oxidation of iron pentacarbonyl in high boiling temperature organic solvents. The results support X-ray diffraction and Transmission Electron Microscope studies of the presence of mixed FexO and Fe3O4 phases within the nanoparticles whose relative content can be altered through heat treatment in nitrogen atmosphere. Furthermore, the Mossbauer study gives evidence of the presence of an amorphous, spin-glass like phase due to spin frustration at the FexO/Fe3O4 interface.
Genetic relicts from the origin of ALL

In this issue of Blood , Bateman and colleagues identify the ETV6-RUNX1 fusion as a common prenatal event at the origin of t(12;21)(p13;q22) ALL.[1][1] Additional genetic lesions in the preleukemic clone are required but follow divergent evolutionary pathways toward overt leukemia. When
Discovery of Novel Heteroarylazoles That Are Metabotropic Glutamate Subtype 5 Receptor Antagonists with Anxiolytic Activity

The highly potent, selective, and brain-penetrant metabotropic glutamate subtype 5 (mGlu5) receptor antagonists 3-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile (47) and 3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile (48) are reported. Compound 47 is active in the rat fear-potentiated startle (FPS) model of anxiety with ED50 = 5.4 mg/kg (po) when dosed acutely. In this model the anxiolytic effects of 47 rapidly tolerate on repeated dosing.
3D fluoroscopy with real-time 3D non-cartesian phased-array contrast-enhanced MRA†

For optimized CE-MRA of the chest and abdomen, the scan time and breath-hold must be coordinated with the arrival of contrast. A 3D fluoroscopy system is demonstrated that performs real-time 3D projection reconstruction acquisition, reconstruction, and visualization using only the standard scanner hardware and operator console workstation. Unlike 2D fluorotriggering techniques, no specification of a monitoring slab or careful placement of the imaging volume is required. 3DPR data are acquired continuously throughout the examination using an eight-channel receiver and 1 s interleaved subframes. The data are reconstructed using 1 s segments for real-time monitoring with 0.8-cm isotropic spatial resolution over the entire torso, allowing full-volume axial, coronal, and sagittal MIPs to be displayed simultaneously with minimal latency. The system later uses the same scan data to generate high-spatial-resolution time-resolved sequences of the breath-hold interval. The 3D fluoroscopy system was validated on phantoms and human volunteers. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc.
Microgravity Bubbly-to-Slug Flow Regime Transition Theory and Modeling

In the published microgravity bubbly-slug data sets, the average critical void fraction for the bubbly-to-slug transition is observed to cluster around $\sim $ 0.20 and $\sim $ 0.45. The origin of what causes there to be two data subsets remains an open question. The $\sim $ 0.20 and $\sim $ 0.45 critical void fractions were reported by one researcher to occur during 1-g and $\mu $ -g intervals on a reduced gravity aircraft, respectively. This suggests that the experiments belonging to the $\sim $ 0.20 data subset may have encountered undue buoyancy effects or perturbations which may have caused the bubbly-to-slug flow regime transitions to occur at prematurely low void fractions. Should this assertion hold, the ∼0.20 data subset can be treated separately from the ∼0.45 data subset, which provides a much clearer picture of the bubbly-to-slug flow regime transition. A new theory has been developed which explains the mechanics of the $\sim $ 0.45 data subset, for which corresponding physical and dimensionless models have been derived. The new theory and models are validated by their clear fit to the entirety of the published ∼0.45 data subset, however, they do not offer a firm explanation of the mechanics of the $\sim $ 0.20 data subset. This provides further indication that these two data subsets are indeed different. Further investigation into the differences between experiments and the manner in which they were conducted may explain the existence of these two data subsets.
The 1988 Stevenson Memorial lecture. Physiological responses to severe hypoxia in man.

Recent measurements at extreme altitude and in low pressure chamber simulations have clarified the human responses to extreme hypoxia. Man can only tolerate the severe oxygen deprivation of great altitudes by an enormous increase in ventilation which has the advantage of defending the alveolar against the reduced inspired . Nevertheless the arterial on the Everest summit is less than 30 Torr (1 Torr = 133.3 Pa). An interesting consequence of the hyperventilation is that the respiratory alkalosis greatly increases the oxygen affinity of the hemoglobin and assists in oxygen loading by the pulmonary capillary. The severe hypoxemia impairs the function of many organ systems including the central nervous system, and there is evidence of residual impairment of memory and manipulative skill in climbers returning from great altitudes. At the altitude of Mt. Everest, maximal oxygen uptake is reduced to 20–25% of its sea level value, and it is exquisitely sensitive to barometric pressure. It is likely that the seas...
Bryostatin 1 induces apoptosis and augments inhibitory effects of vincristine in human diffuse large cell lymphoma

Bryostatin 1 (Bryo1), a macrocyclic lactone and a protein kinase C activator, is isolated from the marine bryozoan Bugula neritina. In this study we describe its effect, alone or after sequential use with vincristine (VCR), on the human diffuse large cell lymphoma cell line WSU-DLCL2. Our results show that both Bryo1 and VCR induced apoptosis as demonstrated by morphological examination, DNA flow cytometry (FCM), and DNA fragmentation on agarose gel electrophoresis. Cells pretreated for 24 h with Bryo1 and then exposed to VCR showed an increase in apoptosis compared to cells that were exposed to Bryo1 or VCR alone. We also studied the effects of Bryo1, VCR and their combination on cell growth, bcl-2 and p53 expression, and inhibition of cell proliferation as measured by [3H]-thymidine incorporation. Cell analysis showed significant growth inhibition of WSU-DLCL2 cells by the Bryo1/VCR combination as compared to either agent alone. Immunocytochemistry (ICC) revealed that relative bcl-2 oncoprotein expression was decreased in cells treated with Bryo1, or VCR separately and was abolished by combining both drugs. When examined by ICC, WSU-DLCL2 cells were initially negative for the p53 protein. However, upon treatment with the above agents, the relative expression of p53 was moderate on Bryo1-or VCR-treated cells and strong on cells treated with the Bryo1/VCR combination. Cell proliferation as measured by [3H]-thymidine incorporation revealed significant inhibition of tumor growth by exposure to the agents when compared to the control. In contrast, Bryo1, VCR and their combination did not show any inhibition of normal bone marrow growth. These findings taken together, suggest that the exposure of WSU-DLCL2 cells to Bryo1 prior to treatment with VCR enhances apoptosis, a phenomenon which might be exploited for future therapies.
Aryl acetylene inhibitors for cytochrome P450-based monooxygenase isozymes

The structures of 1-propynylpyrene (1), 4-ethynylbiphenyl (2), 3-ethynylphenanthrene (3), 9-propynylphenanthrene (4) and 9-ethynylphenenthrene (5) have been determined using MoKα radiation.1 crystallizes in the monoclinic space groupP21/n witha=8.972(2)b=10.136(2),c=14.060(2)A, β=99.77(1)°,V=1260.0(7) A3,Z=4. Refinement of 1261 reflections gaveR=0.042 andRw=0.054.2 crystallizes in the orthorhombic space groupPbcn witha=17.7159(9),b=6.250(2),c=18.544(2) A,V=2053(1) A3,Z=8. Refinement of 1710 observed reflections gaveR=0.046 andRw=0.053.3 crystallizes in the orthorhombic space group Pbca witha=7.891(1),b=16.459(1),c=16.879(2) A,V=2192.2(7) A3,Z=8. Refinement of 1520 observed reflections gaveR=0.032 andRw=0.047.4 crystallizes in the orthorhombic space groupP212121 witha=5.8867(6),b=13.476(1).c=14.838(2) A,V=1177.1(4) A3,Z=4. Refinement of 1217 observed reflections gaveR=0.041 andRw=0.055.5 crystallizes in the monoclinic space groupP21/c witha=27.755(7),b=5.1447(9),c=15.500(2) A, β-105.53(2)°,Z=2133(2) A3,Z=8. There are two independent molecules in the unit cell. Refinement of 1276 observed reflections gaveR=0.061 andRw=0.065. In2–5 there are no significant intermolecular interactions while in1 the molecules are associated in pairs via π-π stacking intarctions. Bond distances within the pyrene and phenanthrene portions of the molecules compare favorably with those found in other derivatives.
Ion-Beam Synthesis of Buried Yttrium Silicide

Buried single-crystal YSi1.7 layers have been synthesized using high fluence implants of 330 keV yttrium ions into (111) Si held at 450°C followed by post-implant anneals of 1000°C . Rutherford backscattering spectrometry showed that an implant fluence of 3.6 X 1017 Y/cm2 forms a continuous layer of uniform thickness. Whereas, implant fluences of 1 — 2 x 1017 Y/cm2 form a thin continuous YSi1.7 layer with what are believed to be Y-silicide precipitates above and below the YSi1.7 layer. Strains resulting from the YSi1-7 layers were evaluated from x-ray rocking curves using a double crystal diffractometer.
Food-Sharing Networks in Lamalera, Indonesia: Status, Sharing, and Signaling

Costly signaling has been proposed as a possible mechanism to explain food sharing in foraging populations. This sharing-as-signaling hypothesis predicts an association between sharing and status. Using exponential random graph modeling, this prediction is tested on a social network of between-household food-sharing relationships in the fishing and sea-hunting village of Lamalera, Indonesia. Previous analyses (Nolin, 2010. Food-sharing networks in Lamalera, Indonesia: reciprocity, kinship, and distance. Human Nature 21, 243–268) have shown that most sharing in Lamalera is consistent with reciprocal altruism. The question addressed here is whether any additional variation may be explained as sharing-as-signaling by high-status households. The results show that high-status households both give and receive more than other households, a pattern more consistent with reciprocal altruism than costly signaling. However, once the propensity to reciprocate and household productivity are controlled, households of men holding leadership positions show greater odds of unreciprocated giving when compared to households of nonleaders. This pattern of excessive giving by leaders is consistent with the sharing-as-signaling hypothesis. Wealthy households show the opposite pattern, giving less and receiving more than other households. These households may reciprocate in a currency other than food, or their wealth may attract favor-seeking behavior from others. Overall, status covariates explain little variation in the sharing network as a whole, and much of the sharing observed by high-status households is best explained by the same factors that explain sharing by other households. This pattern suggests that multiple mechanisms may operate simultaneously to promote sharing in Lamalera and that signaling may motivate some sharing by some individuals even within sharing regimes primarily maintained by other mechanisms.
Masquerading bundle branch block as a marker of poor prognosis

Masquerading bundle branch block is a rare and unique finding on a 12-lead electrocardiogram, consisting of the pattern of right bundle branch block in the precordial leads and left bundle branch block in the limb leads. We experienced a 77-year-old woman with masquerading bundle branch block. She had been well, but died suddenly 9 months after the diagnosis of masquerading bundle branch block. The presence of masquerading bundle branch block indicates severe degeneration of the conduction system, leading to a poor outcome. .
Further evidence for neutrino oscillations from LSND: the νμ → νe decay-in-flight channel

Abstract A search for νμ → νe oscillations has been conducted at the Los Alamos Meson Physics Facility (LAMPF) using νμ from π+ decay in flight (DIF). An excess in the number of beam-related events from the νe C → e− X inclusive reaction is observed. The excess is too large to be explained by normal νe contamination in the beam at a confidence level greater than 99%. If interpreted as an oscillation signal, the observed oscillation probability of (2.6 ± 1.3 ± 0.5) × 10−3 is consistent with the previously reported ν μ → ν e oscillation evidence from LSND.
An Empirical Analysis of Tenant Selection Under Federal Rent Supplement Programs: A First Step

The purpose of this study is to consider the question of whether characteristics of applicants for federally subsidized housing can be used in predicting whether one is accepted or rejected by management as a tenant. Using probit analysis, a statistical model was developed for use in assisting management in objectively screening applicants. Factors found significant in determining the probability of acceptance or rejection were credit ratings, character references, length of time employed, and student status. The percent of rent subsidized by government and sex of household head had little effect on applicant acceptance. Although a meaningful model for estimating the probability of eviction could not be developed, low eviction rates resulting from the tenant selection model suggest that it may serve as a reasonable proxy.
Studies of Interviewer Variance for Attitudinal Variables

Abstract We studied the effects of the variable biases of interviewers on responses to a variety of items, mostly attitudinal, included in two surveys. Not satisfied with “testing statistical significance,” we measured this interviewer variance as a component of the total variance per respondent; thus s 2 =s a 2 + s b 2, where s a 2 is the “between interviewer” and s b 2 the “within interviewer” component; ρ = s a 2/s 2 is the proportion of the interviewer effect. The contribution of the interviewer variance to total survey errors is examined for its implications for the planning and interpretation of survey statistics. Among these we included subclass means and comparisons among pairs of subclasses. The data yielded important results: (1) We can obtain responses with low or moderate interviewer variance on highly “ambiguous” and “critical” attitudinal questions. The range of ρ's was mostly 0 to .07 in the first study, 0 to .05 in the second and their average is about .01 or .02; these effects are not gen...
Magnetic susceptibility of glassy carbon

Abstract The magnetic susceptibility of two grades of Japanese glassy carbon has been measured at room temperature as a function of magnetic field strength, heat treatment temperature and high-temperature tensile deformation. The magnetic behavior was correlated with impurity content and with interlayer spacing and apparent crystallite layer diameter. The structure sensitivity of the diamagnetism of nongraphitizing carbons, such as glassy carbon, is compared with that of graphitizing carbons and some differences are noted and discussed.
Changes in Intracellular Calcium and in Membrane Currents Evoked by Injection of Inositol Trisphosphate into Xenopus Oocytes

Intracellular calcium was monitored by the use of aequorin in voltage-clamped oocytes of Xenopus laevis. Injection of inositol trisphosphate (IP$\_{3}$) into oocytes elicited slowly rising and decaying aequorin/calcium signals and produced oscillatory chloride membrane currents. These responses did not depend upon extracellular calcium, since they could be elicited in calcium-free solution and after addition of cobalt or lanthanum to block calcium channels in the surface membrane. We conclude that IP$\_{3}$ causes the release of calcium from intracellular stores in the oocyte. Injections of calcium gave aequorin and membrane current responses that were more transient than those seen with IP$_{3}$.
MO-D-108-11: Implication of Spot Position Error On Plan Quality in Pencil-Beam Proton Therapy

Purpose: To assess the dosimetric implication of spot position errors on intensity modulated proton therapy (IMPT) treatment plan‐quality and develop an analytical routine to aid in that assessment. Methods: IMPT plans with different spot spacing (SS) (3–6mm) were created on a water phantom and a patient CT using a commercial planning system. Spot position errors (PE) (1–2mm) were simulated by shifting spots away from their planned location using a custom built script. Various perturbations of single‐spot shift and multiple‐spot shift in a correlated and random manner were simulated. The resulting dose perturbations were compared to the original plans to calculate percent dose error (PDE (%)). Results: Spot shifts created hot and cold spots adjacent to the location of the error. In the phantom study of the single‐spot error, the PDE at the largest dose difference has been mapped out in SS and PE space to be a quadratic 3D surface, and the slope of the surface became less steep at the deeper depth. As the global dose distribution reduced from volume to plane and line the PDE increased substantially. For clustered multiple‐spot error the dose perturbation was significantly larger than single‐spot error, but there is saturation for the magnitude of PDE though the perturbation volume increased. In a patient plan, 5% of total spots were clustered which resulted in the PDE of 5 to 6 % and is decreased to 2% when the spots and shift direction are randomly chosen. Conclusion: The dose perturbation is a complex function of PE, SS, depth and global dose distribution. To quantitatively and systematically evaluate the impact of position errors on plan‐quality a simulation tool for both selective and random spot(s) position errors was developed.
Graph separation techniques for quadratic zero-one programming

Abstract In this paper, we consider a divide-and-conquer algorithm for quadratic zero-one programs. The algorithm is based on the use of separators of the related graph. For some classes of problems, the algorithm runs in subexponential or in polynomial time.
Activation of attention networks using frequency analysis of a simple auditory-motor paradigm.

Abstract The purpose of this study was to devise a paradigm that stimulates attention using a frequency-based analysis of the data acquired during a motor task. Six adults (30–40 years of age) and one child (10 years) were studied. Each subject was requested to attend to “start” and “stop” commands every 20 s alternatively and had to respond with the motor task every second time. Attention was stimulated during a block-designed, motor paradigm in which a start–stop commands cycle produced activation at the fourth harmonic of the motor frequency. We disentangled the motor and attention functions using statistical analysis with subspaces spanned by vectors generated by a truncated trigonometric series of motor and attention frequency. During our auditory–motor paradigm, all subjects showed activation in areas that belong to an extensive attention network. Attention and motor functions were coactivated but with different frequencies. While the motor-task-related areas were activated with slower frequency than attention, the activation in the attention-related areas was enhanced every time the subject had to start or end the motor task. We suggest that although a simple block-designed, auditory–motor paradigm stimulates the attention network, motor preparation, and motor inhibition concurrently, a frequency-based analysis can distinguish attention from motor functions. Due to its simplicity the paradigm can be valuable in studying children with attention deficit disorders.
Effects of antibiotic lonophore, A23187, on oxidative phosphorylation and calcium transport of liver mitochondria

Abstract A23187, a new antibiotic with ionophore properties, uncoupled oxidative phosphorylation in mitochondria which oxidized either malate plus glutamate or succinate. Ca 2+ , but not Mg 2+ , enhanced the uncoupling effect. Fluorescence of ANS 1 was increased by A23187 suggesting the mitochondrial membranes were de-energized. This de-energization was presumably by activation of the energy-dependent uptake of Ca 2+ . The steady-state measurements of murexide-divalent cation complexes showed that A23187 caused mitochondria to release the accumulated Ca 2+ to the medium. This reduced the transmembrane Ca 2+ gradient even though normal active Ca 2+ uptake could take place. A23187 inhibited activity of ATPase induced by 2,4-dinitrophenol, valinomycin, and Ca 2+ . The addition of Mg 2+ could prevent this inhibition presumably by maintaining the endogenous Mg 2+ concentration. The above metabolic events could be explained by the fact that molecules of A23187 function in the mitochondrial inner membrane as mobile carriers for divalent cations.
Relative velocity of seagrass blades: Implications for wave attenuation in low‐energy environments

[1] While the ability of subaquatic vegetation to attenuate wave energy is well recognized in general, there is a paucity of data from the field to describe the rate and mechanisms of wave decay, particularly with respect to the relative motion of the vegetation. The purpose of this study was to quantify the attenuation of incident wave height through a seagrass meadow and characterize the blade movement under oscillatory flow under the low-energy conditions characteristic of fetch-limited and sheltered environments. The horizontal motion of the seagrass blades and the velocity just above the seagrass canopy were measured using a digital video camera and an acoustic Doppler velicometer (ADV) respectively in order to refine the estimates of the drag coefficient based on the relative velocity. Significant wave heights (H s ) were observed to increase by ∼0.02 m (∼20%) through the first 5 m of the seagrass bed but subsequently decrease exponentially over the remainder of the bed. The exponential decay coefficient varied in response to the Reynolds number calculated using blade width (as the length scale) and the oscillatory velocity measured immediately above the canopy. The ability of the seagrass to attenuate wave energy decreases as incident wave heights increase and conditions become more turbulent. Estimates of the time-averaged canopy height and the calculated hydraulic roughness suggest that, as the oscillatory velocity increases, the seagrass becomes fully extended and leans in the direction of flow for a longer part of the wave cycle. The relationship between the drag coefficient and the Reynolds number further suggests that the vegetation is swaying (going with the flow) at low-energy conditions but becomes increasingly rigid as oscillatory velocities increase over the limited range of the conditions observed (200 < Re < 800). In addition to the changing behavior of the seagrass motion, the attenuation was not uniform with wave frequency, and waves at a secondary frequency of 0.38 Hz (2.6 s) appeared to be unaffected by the seagrass. Cospectral analysis between the oscillatory and blade velocity suggests that the seagrass was moving in phase with the current at the (lower) secondary frequency and out of phase at the (higher) peak frequency. In this respect, seagrass is not only an attenuator of wave energy but also serves as a low-pass filter; higher frequencies in the spectra tend to be more attenuated.
Dipolar excitons, spontaneous phase coherence, and superfluid-insulator transition in bilayer quantum Hall systems at nu = 1.

The spontaneous interlayer phase coherent (111) state of a bilayer quantum Hall system at filling factor $\ensuremath{\nu}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ may be viewed as a condensate of interlayer particle-hole pairs or excitons. We show that when the layers are biased in such a way that these excitons are very dilute, they may be viewed as pointlike bosons. We calculate the exciton dispersion relation and show that the exciton-exciton interaction is dominated by the dipole moment they carry. In addition to the phase coherent state, we also find a Wigner crystal/glass phase in the presence/absence of disorder which is an insulating state for the excitons. The position of the phase boundary is estimated and the transition between these two phases is discussed.
Electron Collisional Excitation Rates for O I Using the B-Spline R-Matrix Approach

The B-spline R-matrix approach has been used to calculate electron collisional excitation strengths and rates for transitions between the 3P, 1D, and 1S states of ground configuration and from these states to the states of the excited 2s(sup 2)2p(sup 3)ns (n = 3-5), 2s(sup 2)2p(sup 3)np (n = 3-4), 2s(sup 2)2p(sup 3)nd (n = 3-4), 2s(sup 2)2p(sup 3)4f, and 2s2p(sup 5) configurations. The nonorthogonal orbitals are used for an accurate description of both the target wave functions and the R-matrix basis functions. The thermally averaged collision strengths are obtained from the collision strengths by integrating over a Maxwellian velocity distribution of electron energies, and these are tabulated over a temperature range from 1000 to 60,000 K. The parametric functions of scaled energy have also been obtained to represent collision strengths over a wide energy range or thermally averaged collision strengths at any desired temperature.
Integration of Landsat imagery and an inundation model in flood assessment and predictions: A case study in Cook Inlet, Alaska

High-temporal and spatial resolution coastal topography data is important in assessing and predicting floods. This study demonstrates the capability of remote sensing technology in deriving topographic information of flood areas. Cook Inlet, Alaska, with its large (8–10m) tidal range and extensive mudflat regions is selected as a study area. The shorelines at different tidal stages are detected from analysis of water coverage in Landsat satellite images. All the shoreline data from different times are next integrated with water level data from observations and the inundation model to produce a new topography maps. The method indicates a new way to evaluate the flood prediction of the existing Cook Inlet inundation model, and the potential of using remote sensing data to improve the accuracy of flood perditions by obtaining a high-resolution topography data in shallow regions and flood zones where landbase data are not available.
Transient stability of an a.c. generator by Lyapunov's direct method†

The transient stability of an a.c. generator is analysed by utilizing Lyapunov's direct method. Lyapunov functions are developed, which include the effects of flux docay and simplified representations of speed governer and voltage regulator. It is shown that Lyapunov's method can be utilized to estimate reasonably accurately the critical fault clearing time with considerably fewer computations and in much shorter time than by conventional techniques. Furthermore, it is shown how a Lyapunov function can indicate the relative effects of various factors on the stability property of a generator. The Lyapunov functions have been developed essentially by trials based on physical considerations. Various existing methods of constructing the Lyapunov functions were also considered but were found to be of no help in the present study.
Role of proximal tubule in the hypocalciuric response to thiazide of patients with idiopathic hypercalciuria

The most common metabolic abnormality found in calcium (Ca) kidney stone formers is idiopathic hypercalciuria (IH). Using endogenous lithium (Li) clearance, we previously showed that in IH, there is decreased proximal tubule sodium absorption, and increased delivery of Ca into the distal nephron. Distal Ca reabsorption may facilitate the formation of Randall's plaque (RP) by washdown of excess Ca through the vasa recta toward the papillary tip. Elevated Ca excretion leads to increased urinary supersaturation (SS) with respect to calcium oxalate (CaOx) and calcium phosphate (CaP), providing the driving force for stone growth on RP. Thiazide (TZ) diuretics reduce Ca excretion and prevent stone recurrence, but the mechanism in humans is unknown. We studied the effect of chronic TZ administration on renal mineral handling in four male IH patients using a fixed three meal day in the General Clinical Research Center. Each subject was studied twice: once before treatment and once after 4–7 mo of daily chlorthalidone treatment. As expected, urine Ca fell with TZ, along with fraction of filtered Ca excreted. Fraction of filtered Li excreted also fell sharply with TZ, as did distal delivery of Ca. Unexpectedly, TZ lowered urine pH. Together with reduced urine Ca, this led to a marked fall in CaP SS, but not CaOx SS. Since CaOx stone formation begins with an initial CaP overlay on RP, by lowering urine pH and decreasing distal nephron Ca delivery, TZ might diminish stone risk both by reducing CaP SS, as well as slowing progression of RP.
Investigating Driver Headroom Perception: Methods and Models

Recent changes in impact protection requirements have led to increased padding on vehicle interior surfaces. In the areas near the driver’s head, thicker padding can reduce the available headspace and may degrade the driver’s perception of headroom. A laboratory study of driver headroom perception was conducted to investigate the effects of physical headroom on the subjective evaluation of headroom. Ninety-nine men and women rated a range of headroom conditions in a reconfigurable vehicle mockup. Unexpectedly, driver stature was not closely related to the perception of headroom. Short-statured drivers were as likely as tall drivers to rate a low roof condition as unacceptable. Statistical models were developed from the data to predict the effects of changes in headroom on the percentage of drivers rating the headroom at a specified criterion level.
Future of Cholesteryl Ester Transfer Protein Inhibitors

The cholesteryl ester transfer protein (CETP) plays an integral role in the metabolism of plasma lipoproteins. Despite two failures, CETP inhibitors are still in clinical development. We review the genetics of CETP and coronary disease, preclinical data on CETP inhibition and atherosclerosis, and the effects of CETP inhibition on cholesterol efflux and reverse cholesterol transport. We discuss the two failed CETP inhibitors, torcetrapib and dalcetrapib, and attempt to extract lessons learned. Two CETP inhibitors, anacetrapib and evacetrapib, are in phase III development, and we attempt to differentiate them from the failed drugs. Whether pharmacologic CETP inhibition will reduce the risk of cardiovascular disease is one of the most fascinating and important questions in the field of cardiovascular medicine.
Snapfish Lab: An open online imaging community

With the increasing amount of digital media being stored, shared and consumed on the Internet, more imaging applications are deployed online. However, the usability and use model of those applications are often less studied. In this paper, we present Snapfish Lab, an open online imaging community web site, to enable both imaging technologists and enthusiasts participate actively in exploring the usability and use model of the exploratory imaging applications. The main topic addressed in this paper is the challenges and solutions of building a production quality Web site that supports open and high performance imaging application hosting, rich user feedback collection and satisfactory end user experience. The key value offered by Snapfish Lab is to bridge imaging research community and end users so that userpsilas demand becomes part of innovation cycle to drive Web based imaging research and development.
Human natural killer cell activity against porcine targets: modulation by control of the oxidation–reduction environment and role of adhesion molecule interactions

Xenotransplantation, especially using porcine sources, has been proposed as a means to alleviate the shortage of human organs for transplantation. NK cells appear to be important mediators of the xenogeneic immune responses, including the human anti-pig response. Having previously established the redox regulation of NK cell activity against tumor target cells, we now report that the interaction of human NK cells with porcine target cells is also regulated by redox. Thiol-deprivation strongly diminished the capacity of IL-2-activated human NK cells to kill porcine endothelial cells. This inhibition correlated with reduced proliferation and interferon (IFN)-gamma production by IL-2-activated NK cells. For fresh NK cells, pretreatment with diethyl maleate (DEM), which was used to deplete intracellular thiols, reduced lysis of porcine and human targets. Because many adhesion molecules exhibit interspecies recognition, we further investigated whether changes in expression of adhesion molecules might explain our observations. DEM treatment reduced the expression of CD11b and CD29 on fresh NK cells. Monoclonal antibody blocking studies showed that the combination of mAb to CD11b and CD18 reduced lytic activity against both PAEC as well as K562, although other qualitative differences were observed between the porcine and human target cells. These findings suggest that the oxidative stress-induced downregulation of CD18 may be important in modulating cytotoxic activity of fresh NK cells against PAEC and K562 targets through reduced formation of the CD11b/CD18 heterodimer. Thus, the appropriate manipulation of redox status may provide a means to enhance survival of non-human animal tissues in humans through modulation of adhesion molecule expression/interactions.
Telomere shortening exposes functions for the mouse Werner and Bloom syndrome genes

The Werner and Bloom syndromes are caused by loss-of-function mutations in WRN and BLM, respectively, which encode the RecQ family DNA helicases WRN and BLM, respectively. Persons with Werner syndrome displays premature aging of the skin, vasculature, reproductive system, and bone, and those with Bloom syndrome display more limited features of aging, including premature menopause; both syndromes involve genome instability and increased cancer. The proteins participate in recombinational repair of stalled replication forks or DNA breaks, but the precise functions of the proteins that prevent rapid aging are unknown. Accumulating evidence points to telomeres as targets of WRN and BLM, but the importance in vivo of the proteins in telomere biology has not been tested. We show that Wrn and Blm mutations each accentuate pathology in later-generation mice lacking the telomerase RNA template Terc, including acceleration of phenotypes characteristic of latest-generation Terc mutants. Furthermore, pathology not observed in Terc mutants but similar to that observed in Werner syndrome and Bloom syndrome, such as bone loss, was observed. The pathology was accompanied by enhanced telomere dysfunction, including end-to-end chromosome fusions and greater loss of telomere repeat DNA compared with Terc mutants. These findings indicate that telomere dysfunction may contribute to the pathogenesis of Werner syndrome and Bloom syndrome.
Iterative design of suboptimal feedback control for bilinear parabolic PDE systems

Optimal control of infinite dimensional systems is one of the central problems in the control of distributed parameter systems. With the development of high performance computers, numerical methods for optimal control design have regained attention and achieved significant progress, mostly in the form of open-loop solutions. We consider in this work an optimal control problem for a bilinear parabolic partial differential equation (PDE) system. Based on the optimality conditions derived from Pontryagin's maximum principle for a reduced-order model, and stated as a two-boundary-value problem, we propose an iterative scheme for suboptimal closed-loop control design. In each iteration step, we take advantage of linear synthesis methods to construct a sequence of controllers. The convergence of the controller sequence is proved in appropriate functional spaces. When compared with previous iterative schemes, the proposed scheme avoids repeated numerical computation of the Riccati equation and therefore reduces significantly the number of ODEs that must be solved at each iteration step. A numerical simulation study shows the effectiveness of this new approach.
Olympic Dreams: The Impact of Mega-Events on Local Politics. By Matthew J. Burbank, Gregory D. Andranovich, and Charles H. Heying. Boulder: Lynne Rienner, 2001. 203p. 19.95 paper.

Cities' pursuit of economic development activities sits at the interstices of the economic marketplace and political power. Private-sector investment is not realized in a power vacuum; political institutional and politicians' behavior influence, alter, and in many ways determine the kind and location of those private investment decisions. It is no wonder, then, that both economists and political scientists have much to say about the efficiency, effectiveness, equity, and impact of urban economic development. And it is no wonder that volumes have been written on the vast array of urban development projects from a comparative or idiosyncratic perspective. Attracting the quadrennial Olympic games is no exception. Matthew Burbank, Gregory Andranovich, and Charles Heying have performed an impressive task of compiling documents and accounts on the politics and economics surrounding the successful efforts of Los Angeles, Atlanta, and Salt Lake City in luring the Olympics to their cities and regions.
Imputation of missing values in DNA microarray gene expression data

Most multivariate statistical methods for gene expression data require a complete matrix of gene array values. In this paper, an imputation method based on least squares formulation is proposed to estimate missing values. It exploits local similarity structures in the data as well as least squares optimization process. The proposed local least squares imputation method (LLSimpute) represents a target gene that has missing values as a linear combination of similar genes. This algorithm showed better performance than the other imputation methods such as k-nearest neighbor imputation and an imputation method based on Bayesian principal component analysis.
Searchlight analysis: Promise, pitfalls, and potential

Multivariate pattern analysis (MVPA) is an increasingly popular approach for characterizing the information present in neural activity as measured by fMRI. For neuroimaging researchers, the searchlight technique serves as the most intuitively appealing means of implementing MVPA with fMRI data. However, searchlight approaches carry with them a number of special concerns and limitations that can lead to serious interpretation errors in practice, such as misidentifying a cluster as informative, or failing to detect truly informative voxels. Here we describe how such distorted results can occur, using both schematic illustrations and examples from actual fMRI datasets. We recommend that confirmatory and sensitivity tests, such as the ones prescribed here, should be considered a necessary stage of searchlight analysis interpretation, and that their adoption will allow the full potential of searchlight analysis to be realized.
The intrahepatic biliary epithelium in the guinea pig: Is hepatic artery blood flow essential in maintaining its function and structure?

To determine whether hepatic artery blood flow is essential in maintaining the function and structure of bile ductules/ducts, the acute effects of hepatic artery ligation on bile secretion and hepatic ultrastructure were examined in anesthetized, bile duct-cannulated guinea pigs. Sixty minutes after hepatic artery ligation, spontaneous bile flow (5.08 + 0.4 μl per min per gm liver) was virtually the same as that before hepatic artery ligation (5.31 + 0.3 μl per min per gm), as were the choleretic effects of 10 CU per kg per 30 min secretin (7.14 + 0.9 vs. 7.21 + 0.9 μl per min per gm), 300 μg per kg per 30 min glucagon (6.72 + 0.9 vs. 6.59 + 0.8 μl per min per gm) and 60 μmoles per kg per 30 min glycochenodeoxycholate (6.43 + 0.6 vs. 6.45 + 0.6 μl per min per gm). The failure of hepatic artery ligation to affect bile secretory function could not be attributed to the existence of collateral arterial blood flow to the liver. First of all, hepatic artery ligation resulted in diminishing significantly hepatic venous, but not portal, oxygen content. More importantly, in isolated guinea pig livers, perfused through the portal vein alone, secretin, glucagon and glycochenodeoxycholate produced changes in bile flow and composition similar to those seen in vivo. Electron microscopy showed no major ultrastructural changes of hepatic parenchyma and biliary epithelium 2 hr after hepatic artery ligation, or 2 hr after perfusing the liver through the portal vein alone save for some portal edema in the latter instance. Failure to perfuse the hepatic artery resulted in dilatation of periportal bile canaliculi, but no evidence of anoxia was observed. These studies indicate that, in the guinea pig, the intrahepatic biliary epithelium receives oxygen in absence of hepatic artery perfusion. Thus, manipulation of hepatic vascular anatomy is not useful for separating canalicular from ductular function.