cssi/SciSciGPT-SciSciNet huggingface dataset:
Rethinking Backcloth and Traffic: Perspectives from Social Network Analysis and Q-Analysis

Fundamental both to Q-analysis and to social network analysis is the assumption that relational structure influences the behavior of the underlying population. This assumption is expressed in Q-analysis by saying that the backcloth structure permits or forbids traffic on the backcloth. Backcloth structure and traffic are represented rather differently in the two disciplines. In this paper, the two representations are contrasted, with the goal of obtaining a useful cross-fertilization.
Leisure, labor, and the complexity of culture: an anthropological perspective

This paper explores and evaluates several theoretical models dealing with the relationship of leisure time availability and cultural complexity from a cross-cultural, anthropological perspective. C...
Compound Gauss Markov random field model for image segmentation and restoration

A compound Gauss-Markov random field (CGMRF) that models nonstationarity in images is proposed for the segmentation and restoration of blurred and noisy images. At the top level of the CGMRF, a label process, which segments the image into K regions, is modeled by a Gibbs random field (GRF). At the bottom level, pixel intensities in each region are modeled by a stationary, noncausal GMRF. maximum a posteriori (MAP) estimates of segmented and restored images are obtained by maximizing their joint a posteriori distribution, using model parameters identified from the noisy image. A stochastic relaxation method is used for optimization. For faster convergence, deterministic relaxation is implemented. Experimental results on segmenting and restoring a noisy image are presented. >
The circuit breaker—a practical example in engineering optimization

Abstract This paper demonstrates the applicability of optimization techniques to the design of practical mechanisms. In particular, the dynamic response of a Westinghouse Type R Vacuum Circuit Breaker is to be optimized. The breaker model incorporates breaking time as the objective function with nonlinear inequality constraints on mechanism motion, link stresses, and breaker energy. The calculation of the objective function and constraints is aided by the use of IMP (The Integrated Mechanisms Program). It is shown that with the aid of optimization techniques, a 15% reduction in breaking time may be realized.
Role of growth factors in inflammation and repair

Mononuclear cells generate a variety of hormone-like proteins termed growth factors that are instrumental in the evolution and resolution of inflammatory reactions. Many of these growth regulatory molecules have multifunctional properties. For example, the mononuclear cell-derived growth factors, platelet-derived growth factor (PDGF), and transforming growth factor beta (TGF-beta), are potent leukocyte chemoattractants. In addition, TGF-beta, a product of platelets, T lymphocytes, and monocytes, appears to induce the transcription of other monocyte-derived growth hormone genes. In this regard, picomolar concentrations of TGF-beta stimulate peripheral blood monocytes to transcribe the genes for PDGF (c-sis), basic fibroblast growth factor (FGF), interleukin 1 (IL-1), and tumor necrosis factor (TNF). Furthermore, levels of mRNA for TGF-beta, which is constitutively expressed in resting monocytes, are also increased by exogenous TGF-beta. Each of these monocyte products exhibits a plethora of biological activities on other cell types. T lymphocytes, in response to antigen, contribute to this network by secreting growth factors and lymphokines that regulate monocyte growth factor production.
Activated and non-activated glucocorticoid-receptor complexes in rat thymus cells: Kinetics of formation and relation to steroid structure☆

Abstract Previously we showed that when glucocorticoids initially enter rat thymus cells incubated at 37°C. non-activated hormone-receptor complexes are formed within 15 s and are then rapidly replaced by activated complexes. Activated and non-activated forms were identified in cytosols from the cells by DEAE-cellulose chromatography, where they are eluted with progressively higher salt concentrations in what are referred to as Peaks I and II. On DNA-cellulose columns dexamethasone-receptor complexes in cytosols that on DEAE-cellulose give mainly Peak II (the non-activated complex, referred to as Complex II) are not bound significantly: they are eluted at the lowest salt concentration along with free steroid, from which they can be separated by binding to hydroxyapatite. This DNA-cellulose peak is referred to as Peak a. Complexes in cytosols that give only Peak I on DEAE, however, on DNA separate into two components. One of these (Complex Ia) is not bound significantly and appears in Peak a. The other (Complex Ib, presumably the true activated complex) appears in a later Peak b. These three complexes have been measured by first adsorbing Ib with DNA-cellulose, then separating Complexes Ia and II. which are not adsorbed on DNA. by means of a DEAE-cellulose column. When [3H]-dexamethasone is added to cells at 37°C. II is formed within 15 s and is rapidly replaced by Ib, in agreement with our earlier results. Complex Ia accounts for 15–20% of total complexes at all times, and is also present after 120 min at 0°C. Various steroids have been compared on DNA-cellulose after 30 min at 37°C. when the amount of Complex II is negligible. The ratio of Ib to Ia is highest for dexamethasone and triamcinolone acetonide, intermediate for cortisol and corticosterone and lowest for cortexolone (which seems to form only Ia), roughly in proportion to intrinsic glucocorticoid activity. Complex Ia may thus be a third normal form of extranuclear glucocorticoid-rcceptor complex, but the possibility remains that it is an artifact formed after cells are broken. The relation of Complexes Ia, Ib and II to glucocorticoid activity is discussed.
Probabilistic retinal vessel segmentation

Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.
Genomic cloning, complete nucleotide sequence, and structure of the human gene encoding the major intrinsic protein (MIP) of the lens.

Abstract Major intrinsic protein (MIP, also called MP26) is the predominant fiber cell membrane protein of the ocular lens. MIP has been suggested to play a role in cell-cell communication in the lens. Its expression is tissue-specific and developmentally regulated. We have isolated and characterized the human gene encoding MIP and report here its genomic structure and entire nucleotide sequence. The gene is 3.6 kb, contains four exons separated by introns ranging in size from 0.4 to 1.6 kb, and is present in single copy per haploid human genome. Primer extension of human lens RNA indicates that transcription of the gene initiates from a single site 26 nt downstream from the TATA box. Three complete Alu repetitive elements are found in tandem in the 5′-flanking region of the gene, and a single complete Alu sequence is present in the third intron. The interspecies comparisons of the MIP gene coding sequence and homologies to other members of a putative transmembrane channel protein superfamily are also discussed.
Isolation and characterization of polymeric and particulate components of acrylonitrile–butadiene–styrene (ABS) plastics by thermal field-flow fractionation

Thermal field-flow fractionation (ThFFF) is shown here to be capable of isolating the polymeric and rubber particulate components of acrylonitrile–butadiene–styrene (ABS) plastic in a simple analytical procedure. To facilitate the separation, the ionic strength of the two carrier liquids used here (THF and DMF) was brought up to 0.10 mM to increase the retention of the rubber particles. At a field strength (temperature drop) δT of 50 K, the two components were well separated, although the polymer component was not completely resolved from the void peak due to its low molecular weight. To facilitate a more rapid separation of the components, both field programming and high flow-rate conditions were examined in some detail. Both the particle-size distribution (PSD) of the rubber particles and the molecular weight distribution (MWD) of the polymer components were obtained using ThFFF. Measured MWD and PSD agreed favorably with PSD determined by dynamic light scattering and MWD obtained by size-exclusion chromatography. © 1996 John Wiley & Sons, Inc.
A Multicenter Trial Evaluation of the Fibrin/Fibrinogen Degradation Products Test for Detection and Monitoring of Bladder Cancer

AbstractPurpose: Presently there is a lack of effective, noninvasive tests for the detection and monitoring of bladder cancer. Measurement of fibrin/fibrinogen degradation products in urine has been shown to be a useful indicator of bladder carcinoma. The objective of this study was to evaluate the AuraTek FDP rapid immunoassay device for the detection of urinary fibrin/fibrinogen degradation products associated with bladder cancer.Materials and Methods: A prospective multicenter study was conducted to compare AuraTek FDP with urinary cytology and hemoglobin dipstick for the detection of bladder cancer in 192 patients with a history of bladder cancer.Results: AuraTek FDP was significantly more sensitive (68%) than conventional urinary cytology (34%, p <0.001) or hemoglobin dipstick (41%, p <0.001) in the detection of bladder tumors, particularly for low stage low grade disease. In subjects with invasive disease (T2-T4) the AuraTek FDP test had a sensitivity of 100%. Specificity of AuraTek FDP was 96% for ...
SAT and ACT predict college GPA after removing g

Abstract This research examined whether the SAT and ACT would predict college grade point average (GPA) after removing g from the tests. SAT and ACT scores and freshman GPAs were obtained from a university sample (N = 161) and the 1997 National Longitudinal Study of Youth (N = 8984). Structural equation modeling was used to examine relationships among g, GPA, and the SAT and ACT. The g factor was estimated from commercial cognitive tests (e.g., Wonderlic and Wechsler Adult Intelligence Scale) and the computer-adaptive Armed Services Vocational Aptitude Battery. The unique variances of the SAT and ACT, obtained after removing g, were used to predict GPA. Results from both samples converged: While the SAT and ACT were highly g loaded, both tests generally predicted GPA after removing g. These results suggest that the SAT and ACT are strongly related to g, which is related to IQ and intelligence tests. They also suggest that the SAT and ACT predict GPA from non-g factors. Further research is needed to identify the non-g factors that contribute to the predictive validity of the SAT and ACT.
Effects of aging and levodopa on the laryngeal adductor reflex in rats

Dopaminergic neurotransmission plays an essential role in sensorimotor function, and declines with age. Previously, we found the laryngeal adductor reflex (LAR) was increased in excitation by a dopamine receptor antagonist. If this airway-protective reflex is similarly affected by aging, it will interfere with volitional control in older adults. The current study tested whether the LAR was affected by aging, and whether such deficits were reversed by levodopa administration in aging rats. We recorded thyroarytenoid (TA) muscle activity at rest and during elicitation of LAR responses by stimulation of the internal branch of the superior laryngeal nerve (iSLN) in 6-, 18- and 30-month-old rats under alpha-chloralose anesthesia. Using paired stimuli at different inter-stimulus intervals (ISIs), LAR central conditioning, resting muscle activity, and reflex latency and amplitudes were quantified. Numbers of dopaminergic neurons in the substantia nigra pars compacta (SNpc) were measured using tyrosine hydroxylase staining. We found: (1) increased resting TA muscle activity and LAR amplitude occurred with fewer dopaminergic neurons in the SNpc in 18- and 30-month-old rats; (2) decreases in LAR latency and increases in amplitude correlated with reduced numbers of dopaminergic neurons in the SNpc; (3) test responses were greater at 1000ms ISI in 18-month-old rats compared with 6-month-old rats; and (4) levodopa administration further increased response latency but did not alter muscle activity, response amplitude, or central conditioning. In conclusion, increases in laryngeal muscle activity levels and reflex amplitudes accompanied age reductions in dopaminergic neurons but were not reversed with levodopa administration.
Bulk, surface, and annealing properties of grown quasiperiodic tilings

Entropically stabilized quasicrystals are usually modeled as equilibrium ensembles of random tilings although the corresponding kinetics may be very slow. In a recently published model we showed how to circumvent this problem by a growth process with reversible dynamics. In the limit of vanishing growth velocity the grown samples are representative of the equilibrium ensemble. Here, we consider bulk and surface properties of this model, an annealing procedure that heals tears, as well as the extension to other symmetries.
The decomposition of trumethylgallium, triethylgallium and trimethylaluminum on Si(100)

Abstract This paper summarizes the results of a series of previous papers where the decomposition of trimethylgallium (TMGa), triethylgallium (TEGa), and trimethylaluminum (TMAI) on Si(100) wasstudied using TPD, XPS, EELS, and molecular beam techniques. The results show that a low coverges, the TMGa adsorbs molecularly. It then undergoes a series of intramolecular hydrogen transfer processes to yield methane, hydrogen, gallium, and adsorbed carbon. At higher exposures it is also possible to transiently populate a weakly bound state on top of the first monolayer of TMGa. The weakly bound TMGa decomposes above 450 K to yield dimethylgallium (DMGa) and CHx (X = 3,4) groups. The DMGa and some of the CHx groups also desorb. However, some CHx groups remain bound to the substrate. There also is evidence for formation of traces of monomethylgallium. TMAI adsorbs as dimers. The dimers decompose upon heating to 400 K. Thereafter, the chemistry of TMAI decomposition is similar to that for TMGa except that methyl groups in the first monolayer of TMAI have a tendency to migrate to the silicon substrate. TEGa adsorbs as a monomer. It then decomposes via a β-hydrogen elimination process, producing ethylene. This pathway does not deposit carbon. At low temperatures and high incident TEGa fluxes there is a reaction pathway involving trapping of C2Hx groups which does deposit carbon. However, this is a minor reaction pathway. These results explain why TEGa is a much better source gas than TMGa when one needs to produce films with low carbon levels.
Near- and mid-infrared spectroscopic determination of algal composition

The objective of this study was to evaluate whether near-infrared reflectance spectroscopy (NIRS) or mid-infrared reflectance spectroscopy (MIRS) could be used to determine the composition of algal turf scrubber samples. We assayed a set of algal turf scrubber (ATS) samples (n = 117) by NIRS, MIRS, and conventional means for ash, total sugar, mono-sugar, total N, and P content. A subset of these samples (n = 64) were assayed by conventional means, MIRS, and NIRS for total lipid and total fatty acid content. We developed calibrations using all the samples and a one-out cross-validation procedure under partial least-squares regression. This process was repeated using 75% of randomly selected samples to develop the calibration and the remaining samples as an independent test set. Results using the entire sample set demonstrated that NIRS and MIRS can accurately determine ash (r 2 = 0.994 and 0.995, respectively) and total N (r 2 = 0.787 and 0.820, respectively) content, but not phosphorus, total sugar, or mono-sugar content in ATS samples. Results using the 64 sample subset indicated that neither NIRS nor MIRS can accurately determine lipid or total fatty acid content in ATS samples.
Inputs of dissolved and particulate226Ra to lakes and implications for210Pb dating recent sediments

Gamma spectroscopy was used to measure radioisotope (210Pb, 226Ra, 137Cs) activities in sediment cores from 20 lakes and a wetland in Florida, USA. Nine profiles display relatively low ( 5 dpm g−1) and variable 226Ra activities. In the latter group, most display up-core increases in activity. Upper sediments from two lakes (Round and Rowell) possess very high (>20 dpm g−1) 226Ra activities that exceed total 210Pb activities, clearly illustrating disequlibrium between 226Ra and supported 210Pb. Supported 210Pb activity is generally thought to come from in situ, 226Ra-containing detrital mineral particles, and is typically assumed to be in secular equilibrium with 226Ra activity. Since 1966, Round Lake has been augmented hydrologically with 226Ra-rich (∼6.2 dpm L−1) groundwater pumped from the local deep aquifer. Adsorption of dissolved 226Ra to recent Round Lake sediments probably accounts for the high measured 226Ra activities and the pronounced disequilibrium between 226Ra and supported 210Pb in topmost deposits. We suspect that many Florida waterbodies receive some 226Ra-rich runoff and seepage from groundwater pumped for irrigation, residential use, industrial applications, and mining. This may account for up-core increases in 226Ra activity measured in sediment cores from some Florida lakes. Significant groundwater pumping began within the last century, and there has been insufficient time for supported 210Pb to come into equilibrium with adsorbed 226Ra in uppermost deposits. Input of 226Ra-rich groundwater to lakes may occur in any geographic region where local bedrock contains 238U and its daughters. When dissolved 226Ra adsorbs to recent sediments, it complicates accurate estimation of supported 210Pb activity, and confounds calculation of unsupported 210Pb activity that is used in dating models.
The projected atomic structure of a large angle [001]Σ = 5 (θ = 36.9°) twist boundary in gold: Diffraction analysis and theoretical predictions

Abstract The projected atomic structure of a large angle [001]Σ = 5 (θ = 36.9°) twist boundary in Au was determined using X-ray diffraction techniques. The extra reflections resulting from the periodic structure of the boundary were studied using synchrotron radiation. The observed structure factor rules are consistent with the boundary existing in the exact (no translation away from) coincidence configuration. The projected structure was determined using a variable coordinate and reliability factor analysis which was simplified by the low value of Σ, the boundary symmetry and the assumption of a thin boundary region. The structure thus determined consists of groups of atoms which have undergone large rotations about “0”-elements in the planes immediately adjacent to the boundary. The structure is made up of separate patches of median f.c.c. structure in analogy with small angle boundaries. Various structures calculated by computer relaxation techniques using interatomic potentials are also presented and compared with the diffraction results. These structures also show rotational relaxations about “0”-elements but the degree of the rotation is much smaller than was determined by diffraction leading to a distortion of the median f.c.c. structure. Consequently, there is only limited correspondence between the computer results and experimental observations.
Controlled release of anti-inflammatory agent α-MSH from neural implants

Abstract Si-multi-electrode arrays implanted into brain tissue for long-term recording lose electrical connectivity due to the post-implantation inflammatory reaction. This inflammatory reaction creates a physical and electrical gap between the electrode and the surrounding neurons. In this study, novel nitrocellulose-based coatings were developed for the sustained delivery of the anti-inflammatory neuropeptide α-melanocyte stimulating hormone (α-MSH). α-MSH was incorporated in micron-scale nitrocellulose coatings and slow, sustained release over 21 days was attained in vitro. The α-MSH released on day 21 was still bioactive, and successfully inhibited nitric oxide (NO) production by LPS-stimulated microglia. The amount of initial drug loading directly affected the release rate, with higher initial loading increasing the mass released but not the percent of drug released. The surface morphology and thickness of the coatings were examined by scanning electron microscopy (SEM) and profilometry. In addition, impedance measurement showed that the α-MSH loaded nitrocellulose coatings reduced the magnitude of electrode impedance at the biologically relevant frequency of 1 kHz. In conclusion, nitrocellulose-based, bioactive coatings that release anti-inflammatory agents without increasing the impedence of the electrode were successfully fabricated. These coatings have the potential to reduce inflammation at the electrode–brain interface in vivo, and facilitate long-term recordings from Si-multi-electrode arrays.
Cuteness and Disgust: The Humanizing and Dehumanizing Effects of Emotion:

Moral emotions are evolved mechanisms that function in part to optimize social relationships. We discuss two moral emotions— disgust and the “cuteness response”—which modulate social-engagement mot...
Freeze-fracture electron microscopy

The freeze-fracture technique consists of physically breaking apart (fracturing) a frozen biological sample; structural detail exposed by the fracture plane is then visualized by vacuum-deposition of platinum-carbon to make a replica for examination in the transmission electron microscope. The four key steps in making a freeze-fracture replica are (i) rapid freezing, (ii) fracturing, (iii) replication and (iv) replica cleaning. In routine protocols, a pretreatment step is carried out before freezing, typically comprising fixation in glutaraldehyde followed by cryoprotection with glycerol. An optional etching step, involving vacuum sublimation of ice, may be carried out after fracturing. Freeze fracture is unique among electron microscopic techniques in providing planar views of the internal organization of membranes. Deep etching of ultrarapidly frozen samples permits visualization of the surface structure of cells and their components. Images provided by freeze fracture and related techniques have profoundly shaped our understanding of the functional morphology of the cell.
Blood benzene concentrations in workers exposed to oxygenated fuel in Fairbanks, Alaska.

Objective: In November 1992 residents of Fairbanks, Alaska became concerned about the potential health effects of an oxygenated fuel program during which 15% (by volume) methyl tertiary butyl ether (MTBE) was added to gasoline. To address those concerns, we earlier completed a survey of occupational exposure to MTBE. We conducted a follow-up survey of workers’ exposure to benzene from gasoline in Fairbanks. Design: Cross-sectional exposure survey. Methods: We examined blood concentrations of benzene from a convenience sample of workers taken in December 1992 during the oxygenated fuel program and from another convenience sample of workers taken in February 1993 after the program was suspended. Results: In December, the median blood benzene concentration of samples taken from four mechanics after their workshift (postshift) was 1.32 μg/l (range, 0.84–2.61 μg/l), and seven nonmechanics (drivers and other garage workers) had a median postshift blood benzene concentration of 0.27 μg/l (range, 0.09– 0.45 μg/l). In February, nine mechanics had a median postshift blood benzene concentration of 1.99 μg/l (range, 0.92–3.23 μg/l), and nine nonmechanics had a median postshift blood benzene concentration of 0.26 μg/l (range, 0.2–0.46 μg/l). Conclusion: Mechanics had higher blood benzene concentrations than did nonmechanics, but further study is needed to determine the impact of the oxygenated fuel program on exposure to benzene.
Identification of short-circuit location in induction motors using radiated electromagnetic field signatures

Finding the location of partial short-circuit in electrical machines enables the operator to fix specific winding segments before it expands into a larger fault causing major down time. This paper investigates the identification process for locating this type of fault in the windings of a machine through radiated electromagnetic field signatures. It is proposed to recognize short-circuit types such as inter-turn, inter-coil or terminal-turn faults. The location of short-circuit can be identified through the frequency response of the radiated magnetic field of the machine. The responses were compared based on the variations of the amplitudes of the harmonic and inter-harmonic orders. To use this method for various practical situations, two different approaches were used for locating the short-circuit conditions in an optimal manner. The experimental study of short-circuit; especially the major and semi-major cases, could damage the winding. Instead, the full three-dimensional finite element (3DFE) method was utilized in few cases and verified experimentally. Finding the locations of small short-circuit assist engineers in fixing the specific winding fault before a major damage occurs.
Thoracoscopic Extrapleural Pneumonectomy for Mesothelioma

Mesothelioma is the most common primary pleural malignancy. Surgical therapy offers limited cure benefits at the cost of high morbidity. Although technically challenging and performed rarely, a less invasive approach to extrapleural pneumonectomy was developed with the intent to speed convalescence, hasten adjuvant therapies, improve quality of life, and reduce wound surface area for possible tumor contamination.
Unambiguous NMR spectral assignments of salvinorin A.

The complete assignments of the 1H and 13C NMR spectra of the hallucinogenic neoclerodane diterpenoid salvinorin A were determined in three different NMR solvents using HSQC, HMBC and COSY. Solvent systems are described that allow the resolution of all 1H signals. Virtual coupling was observed for the protons at C-2, C-3 and C-4 in the 600 MHz 1H spectrum in CDCl3. The complete assignments of the 1H and 13C NMR spectra of salvinorin B are also reported. Copyright © 2007 John Wiley & Sons, Ltd.
Selective absorption of hydrogen sulphide in tertiary amine solutions

Abstract An approximate model for the rate of simultaneous absorption of H2S and CO2 into aqueous solutions of a tertiary amine is presented, and the model is successfully compared with experimental results of simultaneous absorption. An effect which is not taken into account in the model is shown to become possibly important when the liquid phase is almost a solution of only free amine, and an approximate method of taking such an effect into account is presented. The procedure discussed will be used in a forthcoming work for developing a methodology of designing the required height for a packed absorber for selective removal of H2S.
Shifting foraging strategies in colonies of the social wasp Polybia occidentalis (Hymenoptera, Vespidae)

Social insect colonies can be expected to forage at rates that maximize colony fitness. Foraging at higher rates would increase the rate of worker production, but decrease adult survival. This trade-off has particular significance during the founding stage, when adults lost are not replaced. Prior work has shown that independent-founding wasps rear the first workers rapidly by foraging at high rates. Foraging rates decrease after those individuals pupate, presumably reducing the risk of foundress death. In the swarm-founding wasps, colony-founding units have many workers, making colony death by forager attrition less likely. Do swarm-founding wasps show similar shifts in foraging rates during the founding stage? We measured foraging rates of the swarm-founding wasp, Polybia occidentalis at four stages of colony development. At each stage, foraging rates correlated with the number of larvae present, which, in the founding stages, correlated with the number of cells in the new nest. Thus, foraging rates appear to be demand-driven, with the level of demand in the founding stage set by the size of nest that is constructed. During the founding stage, foraging rates per larva were high initially, suggesting that colonies minimize the development times of larvae early in the founding stage. Later in the stage, foraging rates decreased, which would reduce worker mortality until new workers eclose. This pattern is similar to that shown for independent-founding wasps and likely results from conflicting pressures to maximize colony growth and minimize the risk of colony death by forager attrition.
Haptic Simulation of Manipulator Collisions Using Dynamic Proxies

Haptic simulations aim to create an immersive, interactive computer generated environment, using haptic devices to render forces to the user based on interactions in the virtual world. In many applications, these simulations must be capable of handling interactions between multiple users, multiple hands, and complex virtual tools. In particular, consider the example of simulating two-handed robotic surgery, where each hand independently directs its own surgical robot to manipulate a tool. Traditionally only quasi-static, point-like proxies are used to represent the human in virtual environments. In previous works, we proposed dynamic proxies to improve upon this notion. Giving the proxy first order, velocity based dynamics makes it massless but capable of producing crisp dynamic interaction forces. With this paper, we generalize the proxy concept to the case of independent, multiple degree-of-freedom virtual manipulators, by giving the proxy not only first-order dynamics, but its own kinematic properties as well. Like real robots, the virtual manipulators' tips track the user and master motion while generating force feedback. Interactions between the virtual arms and with other objects are implemented as geometric constraints on the tip velocities, and solved in a linearly constrained least-squares minimization. A stability proof is given in terms of passivity. The approach is demonstrated on an actual two-handed haptic console, running a real-time simulation of a pair of six degree-of-freedom virtual manipulators with cylindrical links.
Investigation into the Formation of N‐Nitrosamines in Heated Chicken Frankfurters

Chicken frankfurters, prepared with various levels of sodium nitrite (0, 20, 40, 60, 100, and 156 ppm) were heated either in a microwave oven, boiled or broiled and then analyzed for N-nitrosamines. As expected, “apparent” N-nitrosamine levels increased with increasing concentrations of sodium nitrite. The effect of the various heating procedures on N-nitrosamine formation was inconclusive, due possibly to the low levels of “apparent” N-nitrosamines present. The two most common N-nitrosamines present appeared to be N-nitrosodimethylamine and N-nitrosomorpholine. However, only in the frankfurter samples prepared with 156 ppm nitrite was the presence of N-nitrosomorpholine confirmed by mass spectrometry.
Balls and bins models with feedback

We examine generalizations of the classical balls and bins models, where the probability a ball lands in a bin is proportional to the number of balls already in the bin raised to some exponent p. Such systems exhibit positive or negative feedback, depending on the exponent p, with a phase transition occurring at p = 1. Similar models have proven useful in economics and chemistry; for example, systems with positive feedback (p > 1) tend naturally toward monopoly. We provide several results and useful heuristics for these models, including showing a bound on the time to achieve monopoly with high probability.
Illusion and Irreality: The Enlargement of Experience

If there is a crossroads between illusion and irreality, what highwayman hangs there to warn us against perceptual robbery? It would appear that these roads cannot intersect, that illusion cannot be irrealized. For the point of irrealizing the particular, the actually given object or event, is that the existence of the particular is put out of play, enabling the phenomenologist to move from actuality to possibility, from the real to the transcendental. So, as Husserl tells us, " . . . the phenomena of transcendental phenomenology will become characterized as irreal [irreal]. Other reductions, the specifically transcendental ones, 'purify' psychological phenomena from what confers on them reality and, with that, their place in the real 'world.' Our phenomenology is to be an eidetic doc trine, not of phenomena that are real, but of phenomena that are transcendentally reduced."2 Nevertheless, the relationship between the ir real and the illusory remains uncertain. Preliminary examples of these "states of affairs" tend to be both misleading and unsatisfying. The water in which the stick appears to be bent is stagnant; the bent is toward the moribund. The illustration has entered the yellow pages. Nor will more re cent examples, more sophisticated contributions from the Gestaltists, say, resolve the problem or allay at least my dissatisfaction. Here illusion seems to transform itself into "seeing-as" rather than presenting what I take to be centrally interesting about illusion: its autonomous contingency. We shall have to find not only a fresh example of illusion but a fresh way of conceiv ing of the fundamental notion of illustration for philosophical purposes. Furniture has ended in futility; the patient with aches and pains has long since been cremated; the fata morganas of visionary love are shrouded; St. Elmo's fire is a false alarm. Where shall we turn for the rejuvenation of language?
Theory of photon-assisted tunneling with radiation-activated barrier impurities

The addition of a new term in the conventional Hamiltonian is used to study photon-assisted tunneling for superconducting junctions containing active barrier impurities. For a sufficiently sharp molecular resonance, the impingent radiation can cause a large enhancement of the $n=1$ Dayem and Martin current step or a significant alteration of the dc Josephson current. The important mechanism is capture of a photon by a molecule followed by electron tunneling through the barrier.
Replicative senescence: the human fibroblast comes of age

Human diploid fibroblasts undergo replicative senescence predominantly because of arrest at the G1/S boundary of the cell cycle. Senescent arrest resembles a process of terminal differentiation that appears to involve repression of proliferation-promoting genes with reciprocal new expression of antiproliferative genes, although post-transcriptional factors may also be involved. Identification of participating genes and clarification of their mechanisms of action will help to elucidate the universal cellular decline of biological aging and an important obverse manifestation, the rare escape of cells from senescence leading to immortalization and oncogenesis.
ALTERED QUANTITATIVE SENSORY TESTING OUTCOME IN SUBJECTS WITH OPIOID THERAPY

Preclinical studies have suggested that opioid exposure may induce a paradoxical decrease in the nociceptive threshold, commonly referred as opioid-induced hyperalgesia (OIH). While OIH may have implications in acute and chronic pain management, its clinical features remain unclear. Using an office-based quantitative sensory testing (QST) method, we compared pain threshold, pain tolerance, and the degree of temporal summation of the second pain in response to thermal stimulation among three groups of subjects: those with neither pain nor opioid therapy (group 1), with chronic pain but without opioid therapy (group 2), and with both chronic pain and opioid therapy (group 3). We also examined the possible correlation between QST responses to thermal stimulation and opioid dose, opioid treatment duration, opioid analgesic type, pain duration, or gender in group 3 subjects. As compared with both group 1 (n=41) and group 2 (n=41) subjects, group 3 subjects (n=58) displayed a decreased heat pain threshold and exacerbated temporal summation of the second pain to thermal stimulation. In contrast, there were no differences in cold or warm sensation among three groups. Among clinical factors, daily opioid dose consistently correlated with the decreased heat pain threshold and exacerbated temporal summation of the second pain in group 3 subjects. These results indicate that decreased heat pain threshold and exacerbated temporal summation of the second pain may be characteristic QST changes in subjects with opioid therapy. The data suggest that QST may be a useful tool in the clinical assessment of OIH.
Purification and characterization of the RNase H domain of HIV-1 reverse transcriptase expressed in recombinant Escherichia coli.

The ribonuclease H (RNase H) domain of human immune-deficiency virus (HIV-1) reverse transcriptase has been produced with the aim of providing sufficient amounts of protein for biophysical studies. A plasmid vector is described which directs high level expression of the RNase H domain under the control of the λ pl promoter. The domain corresponds to residues 427-560 of the 66 kDa reverse transcriptase. The protein was expressed in Escherichia coli and was purified using ion-exchange and size exclusion chromatography. The purified protein appears to be in a native-like homogeneous conformational state as determined by 1H-NMR spectroscopy and circular dichroism measurements. HIV-protease treatment of the RNase H domain resulted in cleavage between Phe-440 and Tyr-441.
Synthesis of Cardiovascular Behavioral Research for Youth Health Promotion

The National Heart, Lung, and Blood Institute (NHLBI) has funded school and family-based research studies for more than a decade. The scientific background for focusing on the major cardiovascular health behaviors with youth is reviewed, as well as the importance of the components in the school health program as a framework for the multiple considerations in school health research. A synthesis of 10 NHLBI funded studies is presented including the sociodemographic characteristics of study populations, study designs, interventions, measures, and results. The studies address single or multiple behaviors, elementary and high school age groups, and multiple ethnic/racial groups, and test various combinations of curriculum, parental involvement, and environmental changes (including school food service).
A modular triple characterization of circuit signatures

We study the modular triples of circuits of a matroid and use them to characterize four types of circuit signatures, three of which are known (weak orientations, orientations, and ternary signatures) and one of which is new (lifting signatures). Lifting signatures allow us to specify a linear class of circuits in a matroid, and thereby the lift of the matroid, by labeling the elements from a group in the manner of Dowling and Kelly.
Relation of forward and backward digit repetition to neurological impairment in children with learning disabilities.

The WISC digit span scaled scores of 297 children with learning disabilities fell below any of their overall I.Q. measures. More than 30 per cent of these Ss also had a greater than normal difference of 3 or more digits between their forward and backward spans. When 292 Ss for whom neurological data were available were categorized according to their signs (none, predominantly left, right, or bilateral), Ss with right-sided signs (presumed left hemisphere damage) were worse on digits forward, while Ss with left-sided signs (presumed right hemisphere damage) were worse on digits backward. Most Ss who could not repeat digits backward at all had bilateral impairment. Analysis of the data by age, suggests that the large gap between forward and backward digits, characteristic of the group with left-sided signs, tends to increase with age since their ability to repeat digits forward improves without concommitant improvement in their ability to repeat them backward. Conversely, the backward span of the group with right-sided signs tends to “catch up” and even equal their limited forward repetition. The data appear to support a left-hemisphere-dependent auditory verbal component of the digit span task reflected in digits forward and a right-hemisphere-dependent, visuo-spatial component reflected in digits backward. The distribution of verbal and performance WISC scores of these Ss, as well as their forward and backward digit spans, suggest that patterns of adult hemispheric asymmetry are similar in children with restricted early brain damage.
Racial and ethnic disparities in severe maternal morbidity: a multistate analysis, 2008-2010.

Objective The purpose of this study was to examine racial and ethnic disparities in severe maternal morbidity during delivery hospitalizations in the United States. Study Design We identified delivery hospitalizations from 2008-2010 in State Inpatient Databases from 7 states. We used International Classification of Diseases, 9th Revision , codes to create severe maternal morbidity indicators during delivery hospitalizations. We calculated the rates of severe maternal morbidity that were measured with and without blood transfusion for 5 racial/ethnic groups: non-Hispanic white, non-Hispanic black, Hispanic, Asian/Pacific Islander, and American Indian/Alaska Native women. Poisson regression models were fitted to explore the associations between race/ethnicity and severe maternal morbidity after we controlled for potential confounders. Results Overall, severe maternal morbidity rates that were measured with and without blood transfusion were 150.7 and 64.3 per 10,000 delivery hospitalizations, respectively. Non-Hispanic black, Hispanic, Asian/Pacific Islander, and American Indian/Alaska Native women had 2.1, 1.3, 1.2, and 1.7 times (all P Conclusion Severe maternal morbidity disproportionally affects racial/ethnic minority women, especially non-Hispanic black women. There is a need for a systematic review of severe maternal morbidities at the facility, state, and national levels to guide the development of quality improvement interventions to reduce the racial/ethnic disparities in severe maternal morbidity.
Density Functional Theory of in Situ Synchrotron Powder X-ray Diffraction on Mesoporous Crystals: Argon Adsorption on MCM-41

The process of gas adsorption on mesoporous crystals can be explored by in situ synchrotron powder X-ray diffraction (XRD) that provides direct information about the distribution of adsorbate with the pore channels. We presented a rigorous theoretical framework for interpretation of the in situ XRD data based on the novel quenched solid density functional theory (QSDFT) model of adsorption on mesoporous materials. QSDFT accounts for the molecular level roughness of the pore walls that is shown to be one of the major factors affecting both the adsorption isotherms and the XRD patterns. Drawing on the example of Ar adsorption in pores of MCM-41, we demonstrate that, using the intermolecular potentials established from the adsorption data and the structural parameters (pore size and roughness) determined from the XRD data, the QSDFT model describes the in situ synchrotron powder XRD intensities on a quantitative level. The QSDFT model provides an opportunity for a unified interpretation of adsorption and XRD...
Synthesis of colloidal microgels using oxygen-controlled flow lithography

We report a synthesis approach based on stop-flow lithography (SFL) for fabricating colloidal microparticles with any arbitrary 2D-extruded shape. By modulating the degree of oxygen inhibition during synthesis, we achieved previously unattainable particle sizes. Brownian diffusion of colloidal discs in bulk suggests the out-of-plane dimension can be as small as 0.8 μm, which agrees with confocal microscopy measurements. We measured the hindered diffusion of microdiscs near a solid surface and compared our results to theoretical predictions. These colloidal particles can also flow through physiological microvascular networks formed by endothelial cells undergoing vasculogensis under minimal hydrostatic pressure (∼5 mm H2O). This versatile platform creates future opportunities for on-chip parametric studies of particle geometry effects on particle passage properties, distribution and cellular interactions.
The clearance rate of microzooplankton as the key element for describing estimated non-linear dilution plots demonstrated by a model

The objective of this study was to determine whether the clearance rate of grazers (as an individual response) was sensitive enough to describe non-linear plots estimated by dilution experiments for measuring the instant grazing rate of microzooplankton. The study was based on an initial analysis of a non-linear feeding pattern based on the food concentration dependence of clearance rate of microzooplankton. In contrast to the traditional assumption of a linear functional response, I assumed that the microzooplankton functional response was non-linear and that the dependence of the clearance rate can be sub-divided into four intervals of food concentration (Sections I–IV) as follows: in Section I clearance rate is zero; Section II is a transitional interval in which the clearance rate increases from zero to a maximum value; in Section III, the clearance rate is maximal and constant, and in Section IV, the clearance rate decreases from its maximum value due to saturated ingestion rate. A set of derived differential equations describes the phytoplankton growth rate in each section, leading to the possibility of comparing predicted non-linear dilution plots with observed non-linear dilution data, using only the specific solutions for Sections III and IV. One should evaluate the quality of fit provided by the non-linear and linear models, rather than uncritically accepting only the linear model for observed non-linear dilution data, using calculated expected non-linear and linear dilution plots as alternative hypotheses. It can be demonstrated that the non-linear model provided a better fit to estimated non-linear dilution data from the Red Sea, Rhode River Estuary (USA) and Kiel Fjord (Germany) than the standard linear model. Published dilution experiments which had a non-linear shape were also selected as illustrative examples to demonstrate the superior fit of the non-linear model.