cssi/SciSciGPT-SciSciNet huggingface dataset:
COMPARATIVE LEAF STRUCTURE OF AQUATIC POLYGONUM SPECIES

A B S T R A C T A systematic study of leaf morphology and anatomy of native, aquatic Polygonum species is presented, treating 60 populations propagated in a common greenhouse. On the basis of this study it is now possible to distinguish American Polygonum species by leaf characters alone. Taxa in section Persicaria are contrasted and also compared with representatives of sections Bistorta and Echinocaulon. A complete description, utilizing 40 leaf characters, is given for each taxon. Complex glands, designated valvate chambers, are shown to be a consistent feature of the P. punctatum species-complex, whereas epidermal storage-idioblasts are present only in certain populations of this group. All other species lack valvate chambers but possess idioblasts, which may reach a frequiency of over 400/mm2 in P. hirsutum. The plate-like multicellular gland of P. opelousanum is found to occur sporadically in P. hydropiperoides, thereby losing its specific diagnostic value. Illucidation of the characteristic structure of this gland, however, lends evidence to discourage the theory that it is an abortive structure produced by a hybrid between glandular and non-glandular species. Reticulate venation and unicellular trichomes separate members of section Bistorta from the smartweeds, but P. meisnerianum (section Echinocauilon) is shown to simulate leaf struicture of the persicarias both internally and externally.
Exercise-induced mitral regurgitation is a predictor of morbid events in subjects with mitral valve prolapse

Objectives. This study attempted to determine whether a subset of patients with mitral valve prolapse and no mitral regurgitation at rest will develop mitral regurgitation during exercise and have a higher than anticipated risk of morbid cardiovascular events. Background. Mitral regurgitation in patients with mitral valve prolapse identifies a subset of patients at higher risk for morbid events. However, mitral regurgitation in patients with mitral valve prolapse may be intermittent and could go unrecognized. A provocative test to unmask mitral regurgitation in these patients would be useful. Methods. Ninety-four adult patients with mitral valve prolapse and no mitral regurgitation at rest were studied during supine bicycle ergometry using color flow Doppler echocardiography in the apical four-chamber and long-axis views. Patients were prospectively followed up for morbid events. Results. Thirty (32%) of 94 patients had exercise-induced mitral regurgitation. Prospective follow-up (mean 38 months) showed more morbid events in the group with than without mitral regurgitation and included, respectively, syncope (43% vs. 5%, p Conclusions. In patients with mitral valve prolapse without mitral regurgitation at rest, exercise provokes mitral regurgitation in 32% of patients and predicts a higher risk for morbid events.
2. Local Improvements And Centralization In Nineteenth-Century England

By the middle years of the nineteenth century, Englishmen were in full revolt against the principle of centralization. Parliament's experiments in centralized administration had almost all ended in failure. A powerful and independent Poor Law Commission had given way, in 1847, to a more timid Poor Law Board under ministerial and parliamentary control. A strong Board of Health, ruled by that uncompromising centralizer and bureaucrat, Edwin Chadwick, was sheared of a large part of its influence when, in 1854, the government decided to release Chadwick from their employment. The Times responded to this event with a jubilant leader article which announced that, ‘If there is such a thing as a political certainty among us, it is that nothing autocratic can exist in this country.... Mr Chadwick and Dr Southwood Smith, have been deposed, and we prefer to take our chance of cholera and the rest than be bullied into health’.
Physical characterization of nedocromil sodium hydrates

Nedocromil sodium, which is used in the treatment of reversible obstructive airway diseases, such as asthma, is found to exist in the following hydrate phases: the heptahemihydrate, the trihydrate, a monohydrate, and an amorphous phase which contains variable amounts of water (1.5-3.0 mol). An anhydrate phase is formed from the trihydrate at zero humidity at >/= 150 degrees C, but is rapidly hydrated under ambient conditions. The physical and thermodynamic properties of the four hydrate phases were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) at ambient and elevated temperatures, hot-stage microscopy (HSM), solid phase interconversion at various relative humidities (RH), intrinsic dissolution rate (IDR), equilibrium solubility measurements, and critical RH measurements. Below 100 degrees C in open pan TGA, the heptahemihydrate and the amorphous forms lose virtually all their water, the monohydrate loses negligible amounts of water, whereas the trihydrate loses the first two moles of water. From 130 degrees C to 200 degrees C in open pan TGA the trihydrate and the monohydrate lose their last mole of water to form the anhydrate. In crimped pan DSC, the thermal events observed are analogous to those observed in open pan TGA, but the temperatures are increased by about 75 degreesC for all except the heptahemihydrate, for which the thermal events are more complex. When the heptahemihydrate is heated in a crimped pan, a melting endotherm is observed at about 75 degrees C followed by three dehydration endotherms. For the crystalline hydrate phases at 22 degrees C, the ranges of stability are as follows: the monohydrate from 0 to 6.4% RH; the trihydrate from 6.4 to 79.5% RH; the heptahemihydrate above 80% RH. A microbalance study showed that the heptahemihydrate is kinetically stable over the range 11 to 79.5% RH. The IDR in water at 25 degrees C under constant hydrodynamic conditions decreases in the rank order: monohydrate > trihydrate > heptahemihydrate, corresponding to the rank order of free energy with respect to the aqueous solution. The equilibrium aqueous solubility of the heptahemihydrate at 25.0 +/- 0.2 degrees C is 0.956 +/- 0.010 M.
Photonic crystal multichannel drop filter and heterostructure beam splitter

Photonic crystals have impacted the diverse domain of electromagnetics. With a growing interest, due to their unique ability to control the propagation of light through a periodic dielectric structure, photonic crystals can be integrated with opto-electronic devices to enhance their optical performance. In this paper we investigate two applications of photonic crystals. First, as a multi- channel drop filter, which consists of a waveguide and a frequency selective element (microcavity); and, secondly, as a hetero-structure beam splitter. We also compare the performance of the hetero-structure with that of a uni- structure beam splitter. A Finite-Difference Time-Domain technique was used to stimulate both applications.
Multiple stimulus discrimination learning, IL Effects of prior training

Performance on multiple-stimulus visual discriminations improved as a function of amount of prior training on another visual discrimination. Performance on the multiple-stimulus tasks, however, indicated no changes in positive and negative stimulus control as prior training was increased from criterion performance to include overtraining. It was concluded that the greater S+ control following overtraining found in previous data may not be generalized stimulus control but specific to the stimuli used in acquisition.
Effects of stress and tranylcypromine on amphetamine-induced locomotor activity and GABAB receptor function in rat brain

Modification in gamma-aminobutyric acid-B (GABA(B)) receptors may contribute to the symptoms of some neurological and psychiatric disorders and to the clinical response to psychotherapeutics. The present study was undertaken to determine whether chronic administration of tranylcypromine (TCP), an antidepressant, and chronic stress influence GABA(B) receptor function in rat brain. The results indicate that TCP treatment, but not stress, increases GABA(B) receptor activity in the cerebral cortex, as measured by baclofen-stimulated GTPgammaS binding. In addition, chronic administration of TCP enhances significantly the locomotor response to a single dose of amphetamine, an effect that is abolished by restraint stress. These results indicate that although TCP administration modifies brain GABA(B) receptor activity, which may contribute to the antidepressant response to this agent, this effect is unrelated to the interaction of stress and TCP treatment on the locomotor response to amphetamine.
Mode coupling theory for calculating the memory functions of flexible chain molecules: Influence on the long time dynamics of oligoglycines

A recent theory for the long time dynamics of flexible chain molecules is tested for the internal dynamics of triglycine and octaglycine, systems which are much more complicated than the previously studied alkanes. The theory extends the generalized Rouse (GR) theory used for the dynamics of polymers by providing a systematic procedure for including the contributions from internal friction and memory function matrices which are neglected in the GR theory. The mode‐coupling method expresses the time correlation functions in terms of the eigenvalues and eigenfunctions of the diffusion operator and determines the eigenvalues by expanding the eigenfunctions in a suitable basis set. The greater complexity of the polyglycine interaction potential and the presence of cooperative local conformational transitions require including higher order mode coupling contributions than previously used. A major computational impediment induced by this requirement is the enormous growth in size of the basis set with the addition of the higher order mode coupling contributions that are needed to describe the influence of the memory functions. This impediment is alleviated by a new sorting procedure that includes in the basis set only the mode coupling functions with the slowest first order relaxation times. The theory is compared with Brownian dynamics (BD) simulations, so that both theory and simulation use identical, realistic potential functions and identical models for the solvent. The new method describes motions on time scales more than an order of magnitude longer than those accessible to molecular dynamics simulations. Inclusion of the memory functions greatly influences the dynamics, and the theory produces excellent agreement with the BD simulations for the long time motions. Individual BD trajectories exhibit the local and correlated conformational transitions.
The effect of hexachlorophene on the respiration of brain and liver mitochondria

Abstract Hexachlorophene (HCP) in micromolar concentrations increased the rates of respiration of rat liver or calf brain mitochondria utilizing succinate or glutamate plus malate as substrate. Higher concentrations of HCP produced a stimulation of respiration followed by inhibition. When respiration in the presence of ADP had been inhibited by oligomycin, HCP was still capable of stimulating respiration. These observations are typical for uncouplers of oxidative phosphorylation.
SU-E-T-266: Shielding Measurements for a Proton Therapy Facility

Purpose: This paper is a follow up on the analytical calculations for the Roberts Proton Therapy Center with empirical data to determine the precision of the calculations from Avery, et al. Methods: Neutrak dosimeters were placed in two sets around the facility while it was in operation at points of interest examined in Avery, et al. The doses to these dosimeters were recorded over one month for one set and two months for the other. Dosimeters that both recorded a dose and could be practically examined were compared to the doses predicted via the analytical method of Avery, et al. at their point of placement. Results: Two points showed a less than 10% difference to the calculated doses. One point shielded by both concrete and pre‐cast blocks and one point shielded by both concrete and the facility's cyclotron were not as precise. Conclusions: The analytical calculation method explored in Avery, et al. is fairly precise in describing the dose at various points in the facility shielded only by concrete. for materials other than concrete, such as the make‐up of the cyclotron or varying wall material, it warrants follow up calculations using the same method.
Characterization of airborne and bulk particulate from iron and steel manufacturing facilities.

Characterization of airborne and bulk particulate material from iron and steel manufacturing facilities, commonly referred to as kish, indicated graphite flakes and graphite flakes associated with spherical iron oxide particles were unique particle characteristics useful in identifying particle emissions from iron and steel manufacturing. Characterization of airborne particulate material collected in receptor areas was consistent with multiple atmospheric release events of kish particles from the local iron and steel facilities into neighboring residential areas. Kish particles deposited in nearby residential areas included an abundance of graphite flakes, tens of micrometers to millimeters in size, and spherical iron oxide particles, submicrometer to tens of micrometers in size. Bulk kish from local iron and steel facilities contained an abundance of similar particles. Approximately 60% of blast furnace kish by volume consisted of spherical iron oxide particles in the respirable size range. Basic oxygen ...
Regulation of pancreatic somatostatin gene expression by insulin and glucagon.

Abstract Rainbow trout were used as a model system to study the effects of insulin and glucagon on the expression of preprosomatostatins (PPSS). We previously showed that the endocrine pancreas of trout contains three mRNAs that encode for distinct somatostatin-containing peptides: PPSS I, which contains somatostain-14 (SS-14) at its C-terminus, and two separate PPSS IIs, PPSS II′ and PPSS II′′, each containing [Tyr 7 , Gly 10 ]-SS-14 at their C-terminus. Rainbow trout injected (100 ng/g body weight) with insulin displayed elevated expression of PPSS II′ and PPSS II′′ mRNAs. Glucagon-injected (100 ng/g body weight) animals displayed elevated pancreatic expression of all PPSS mRNAs compared to saline-injected control animals. Insulin directly stimulated the expression of pancreatic PPSS II′ and PPSS II′′ mRNAs in vitro in a dose-dependent manner in the presence of 4 mM glucose. Glucagon, in the presence of 10 mM glucose, directly stimulated the expression of all PPSS mRNAs in a dose-dependent manner in vitro. These results indicate that the pancreatic expression of PPSS mRNAs is differentially regulated by insulin and glucagon and that the regulatory pattern is dependent on glucose concentration.
Statistical tests for recessive lethal-carriers.

Abstract This paper presents a statistical method for testing whether a male mouse is a recessive lethal-carrier. The analysis is based on a back-cross experiment in which the male mouse is mated with some of his daughters. The numbers of total implantations and intrauterine deaths in each litter are recorded. It is assumed that, conditional on the number of total implantations, the number of intrauterine deaths follows a binomial distribution. Using computer-simulated experimentation it is shown that the proposed statistical method, which is sensitive to the pattern of intrauterine death rates, is more powerful than a test based only on the total number of implant deaths. The proposed test requires relatively simple calculations and can be used for a wide range of values of total implantations and background implant mortality rates. For computer-stimulated experiments, there was no practical difference between the emperical error rate and the nominal error rate.
Concepts In Distributed Systems

We describe a parallel, distributed, associative model based on Hebbian modification of connection strengths between simple elements. Some extensions to the simple model are described and interpretations of the model as a gradient descent algorithm and as maximizing a probability density function are given. The model is applied to concept formation, since most versions of this modelling approach form equivalence classes of inputs that act like much like psychological concepts. Some computer simulations of concept-like behavior are described. Some kinds of computation can be performed effectively with these techniques.
The effect of a moving foveal target on the subjective sensation of motion

In this paper, we report on two experiments concerning the effect of the visual field of fovea on the subjective estimation of angular velocity. Experiment 1 investigates the effect of a slow moving target on the perception of self motion. The result of this experiment can be summarized as follows: a slow moving target seen in the visual field of fovea by a stationary person generates in this person a sensation of self rotation in the same direction as the motion of the target. This phenomenon will be called foveal induced ego motion. Experiment 2 investigates the latency for the detection of a self angular acceleration when the person focusses his fovea on a slowly moving target. From the results of this experiment we conclude that the latency for detection of a small self angular acceleration is shorter if the person sees a small foveal target moving with respect to the person in the direction of self rotation than if that small foveal target is moving (with respect to the person) in the opposite direction. The results of these experiments help us in refining existing models of visual-vestibular interaction, by providing a model which accounts for the phenomenon of oculogyral illusion.
Wideband in-phase/quadrature imbalance compensation using finite impulse response filter

The authors proposed an in-phase/quadrature (I/Q) imbalance compensation technique for wideband digital receiver applications. An I/Q channel-based receiver can double the receiver working bandwidth. However, the amplitude/phase imbalance of an imperfect hybrid coupler can generate image signals thus reducing the receiver's instantaneous dynamic range. They developed a finite impulse response filter-based technique to mitigate deleterious effects because of the amplitude/phase imbalance. Both simulations and experiments were conducted to verify validity of the developed algorithm. The simulation and experiment results show that the proposed imbalance mitigation technique can reduce image signal powers by more than 24 dB or down to noise level. A receiver system level simulation is also conducted to demonstrate the practicality of the proposed imbalance mitigation method.
Thin-layer chromatography of malto-oligosaccharides.

Abstract Procedures for the separation, location and elution of malto-oligosaccharides are described. Best separations were obtained on glass plates (20 × 46 × 0.5 cm) coated with Kieselguhr G, serially developed in solvents of varying proportions of x-butanol, pyridine and water. Major zones were temporarily visualized by exposing the plates to iodine vapors. The located zones were eluted from the thin-layer plates into fiberglass filter pieces with water. Radioactivity of the zone can be determined directly by placing the filter in a toluene-based scintillation fluid and counting in a scintillation counter. After radioactivity determination, the carbohydrates can be eluted from the filter with water and quantitatively measured.
Regression and Correlation for Two Metric Variables

Questions about relationships between metric variables with well-defined units of measurement, such as food calories and fat content, gas mileage and vehicle weight, are answered using the statistical methods know as regression analysis and correlation analysis. Regression and correlation analyses represent two major and complementary aspects of the analysis of the relationship between metric variables.
Effect of Trap Position, Habitat, and Height on the Capture of Pepper Maggot Flies (Diptera: Tephritidae)

Trapping results indicate that pepper maggot, Zonosemata electa (Say), flies occupy tree canopies adjacent to fields when not on host plants. Several in- and near-field trap positions were used to find a reliable monitoring system for adult pepper maggots. Traps baited with liquid ammonium hydroxide (Stills-style trap), hung in the canopy of trees on the edges of pepper fields, caught significantly more Z. electa flies than when positioned lower along the treeline or in the field. In a second experiment, significantly more pepper maggot flies were captured in sugar maples compared with choke cherry trees, which indicates a pest preference for certain nonhost habitats. The lowest trap height tested (2.1 m) failed to capture Z. electa flies in either tree species when the pest population level was low. These studies demonstrated that pepper maggot flies can be reliably detected with Stills-style traps positioned at ≈6.4 m height within the canopy of sugar maple trees adjacent to pepper fields. Fruit oviposition scars also are useful site-specific indicators of pepper maggot presence/absence and may aid in determining if insecticide applications are necessary and in timing sprays.
Gating Kinetics of the α1i T-Type Calcium Channel

The α1I T-type calcium channel inactivates almost 10-fold more slowly than the other family members (α1G and α1H) or most native T-channels. We have examined the underlying mechanisms using whole-cell recordings from rat α1I stably expressed in HEK293 cells. We found several kinetic differences between α1G and α1I, including some properties that at first appear qualitatively different. Notably, α1I tail currents require two or even three exponentials, whereas α1G tails were well described by a single exponential over a wide voltage range. Also, closed-state inactivation is more significant for α1I, even for relatively strong depolarizations. Despite these differences, gating of α1I can be described by the same kinetic scheme used for α1G, where voltage sensor movement is allosterically coupled to inactivation. Nearly all of the rate constants in the model are 5–12-fold slower for α1I, but the microscopic rate for channel closing is fourfold faster. This suggests that T-channels share a common gating mechanism, but with considerable quantitative variability.
Nonsubsampled contourilet transform: filter design and applications in denoising

In this paper we study the nonsubsampled contourlet transform. We address the corresponding filter design problem using the Mc-Clellan transformation. We show how zeroes can be imposed in the filters so that the iterated structure produces regular basis functions. The proposed design framework yields filters that can be implemented efficiently through a lifting factorization. We apply the constructed transform in image noise removal where the results obtained are comparable to the state-of-the art, being superior in some cases.
Methodological Trends in Journal of Personality 1970–1995

One hundred fifty randomly selected articles published in Journal of Personality from 1970 to 1995 were evaluated with regard to subject population, sampling, research design, dependent measures, statistical methods, methodological difficulty, sample size, manipulation of independent variables (for experimental studies), use of manipulation checks, and gender representation of authors and participants. Our findings support Endler and Speer’s (this issue) conclusion that the typical study in personality research continues to use a cross-sectional design, questionnaire measures, and undergraduate participants. Echoing West et al.'s (1992) findings for Journal of Personality and Social Psychology, we found that whereas subject recruitment and design implementation appear to be less difficult than they were two decades ago, statistical analyses have become somewhat more complex.
Combined tapered resistive and inductive loading to increase the bandwidth of small antennas

A loading technique that combines both resistive and inductive tapered loadings to improve the efficiency of the monopole and yet maintain uniform nonresonant impedance characteristics which makes a good impedance match possible, is introduced. In order to increase the radiating power and thus the efficiency of the resistively tapered monopole, tapered inductive loading is employed primarily to counteract the high capacitive reactance at the lower end of the frequency band and thus increase the radiating power of the antenna. Several profiles for the inductive loading were tested and were found to give, depending on the load, an improvement in the radiation power of the antenna. However, only one among the different loading profiles used was able to increase the efficiency and yet maintain very favorable broadband matching characteristics. >
Cortisol production rate in posttraumatic stress disorder.

Context: Several authors have reported the unsuspected finding of low cortisol levels (urinary, salivary, and serum) in patients with posttraumatic stress disorder (PTSD). Objective: Our objective was to assess concentrations of cortisol and its predominant metabolites, cortisol production rate (CPR), and glucocorticoid receptor (GR) binding characteristics in PTSD compared with normal subjects. Design: Matched PTSD patients and control subjects had CPR determined by a stable isotope dilution technique after infusion of deuterated cortisol. Serum cortisol, urinary cortisol, and its metabolites were measured by gas chromatography/mass spectrometry. GR binding capacity (Ro) and ligand binding affinity (Kd) were measured in mononuclear leukocytes. Setting: All subjects were tested during a 40-h admission in an inpatient clinical research center. Patients and Participants: Ten patients with PTSD were matched by age and gender with 10 controls. Outcome Measures: Statistical comparison was conducted for various...
Optimisation of a real-time multi-period truck dispatching system in mining operations

In recent years, there has been considerable research on optimisation of long-term and short-term open pit mine plans to maximise the net present value of a given mining project. The typical goal of truck allocation models in the literature is either minimisation of the number of trucks required to pursue the production target for a given operational period or maximisation of the production based on the available trucks and shovels. With this framework, there is no guarantee of meeting the main goal of a mining project, which is maximisation of the net present value. The objective of this research is to develop a linear programming model for truck allocation, and to utilise it in conjunction with the existing mixed integer programming model for short and long-term mine planning. We test a linear programming model and run it with a mixed integer-programming model concurrently and interactively for solving truck allocation problem. The proposed approach of truck allocation overcomes the shortcomings of the existing models by taking into account economic parameters, multi time periods and the uncertainty of load and travel times and ore grades. We provide a case study of McLaughlin gold mine to show the implementation of our model.
Morphological Transition of Epitaxial Rhodium (111)

We report a global morphological transition in the nucleation and growth of epitaxial Rh (111). The transition occurs near 600 K, about 1/4 of the Rh melting temperature, and is signaled by a change in the shape of the surface features from fingered to compact. The transition appears to be related to a change in the critical nucleation size from 1 to 2 atoms. On both sides of the transition, there lies a regime of persistent layer-by-layer growth indicated by a minimum in surface roughness and by the presence of RHEED oscillations. The general surface features exhibit well defined length scales that are not self-affine, and as growth proceeds they increase in size following a power-law dependence on film thickness with a temperature-independent exponent of 0.33 ± 0.03. The results suggest a general pathway to the layer-by-layer growth of close-packed metals.
Separating spatial search and efficiency rates as components of predation risk

Predation risk is an important driver of ecosystems, and local spatial variation in risk can have population-level consequences by affecting multiple components of the predation process. I use resource selection and proportional hazard time-to-event modelling to assess the spatial drivers of two key components of risk—the search rate (i.e. aggregative response) and predation efficiency rate (i.e. functional response)—imposed by wolves ( Canis lupus ) in a multi-prey system. In my study area, both components of risk increased according to topographic variation, but anthropogenic features affected only the search rate. Predicted models of the cumulative hazard, or risk of a kill, underlying wolf search paths validated well with broad-scale variation in kill rates, suggesting that spatial hazard models provide a means of scaling up from local heterogeneity in predation risk to population-level dynamics in predator–prey systems. Additionally, I estimated an integrated model of relative spatial predation risk as the product of the search and efficiency rates, combining the distinct contributions of spatial heterogeneity to each component of risk.
Morphine reduces local cytokine expression and neutrophil infiltration after incision

Background: Inflammation and nociceptive sensitization are hallmarks of tissue surrounding surgical incisions. Recent studies demonstrate that several cytokines may participate in the enhancement of nociception near these wounds. Since opioids like morphine interact with neutrophils and other immunocytes, it is possible that morphine exerts some of its antinociceptive action after surgical incision by altering the vigor of the inflammatory response. On the other hand, keratinocytes also express opioid receptors and have the capacity to produce cytokines after injury. Our studies were directed towards determining if opioids alter cytokine production near incisions and to identify cell populations responsible for producing these cytokines. Results: A murine incisional model was used to measure the effects of acute morphine administration (0.1–10 mg/kg) on nociceptive thresholds, neutrophil infiltration and cytokine production in hind paw skin 30 minutes and 2 hours after incision. Incised hind paws displayed profound allodynia which was reduced by morphine (0.1–10 mg/kg) in the 2 hours following incision. Skin samples harvested from these mice showed enhanced levels of 5 cytokines: IL-1β, IL6, tumor necrosis factor alpha (TNFα), granulocyte colony stimulating factor (G-CSF) and keratinocyte-derived cytokine (KC). Morphine reduced these incision-stimulated levels. Separate analyses measuring myeloperoxidase (MPO) and using immunohistochemistry demonstrated that morphine dose-dependently reduced the infiltration of neutrophils into the peri-incisional tissue. The dose of morphine required for reduction of cytokine accumulation, however, was below that required for inhibition of peri-incisional neutrophil infiltration. Additional immunohistochemical studies revealed wound edge keratinocytes as being an important source of cytokines in the acute phase after incision. Conclusion: Acute morphine administration of doses as low as 0.1 mg/kg reduces peri-incisional cytokine expression. A reduction in neutrophil infiltration does not provide a complete explanation for this effect, and keratinocytes may be responsible for some incision area cytokine production. These studies suggest that morphine may alter the inflammatory milieu of incisional wounds, but these alterations do not likely contribute significantly to analgesia in the acute setting.
Examination of the Dynamic Mechanical Properties of Tissue Engineering Scaffolds

Scaffolds of both natural and synthetic materials have been widely utilized to provide a three dimensional environment for cell growth. The characteristics of these scaffolds play a vital, but sometimes ambiguous, role in tissue engineering constructs. Collagen-glycosaminoglycan matrices have been used clinically as artificial skin implants. Previous research in our laboratory on this model has shown that gene expression is regulated by mechanical stress applied to the matrix. In this work we begin the process of quantifying the effects of mechanical stress and preparation technique on a matrix comprised of type I collagen and chondroitin-6-sulfate. Compressive loads were applied to the matrices using a dynamic mechanical analyzer at 37 degrees Celsius and retrofitted with 5% carbon dioxide gas flow. All samples were tested hydrated in either simulated body fluid or PBS. Storage and loss modulus data are presented. Mechanical tests were performed on collagen-GAG meshes both seeded with human dermal fibroblasts and not seeded with cells. Continuing work includes gene expression analysis of the cells on the seeded matrices in order to identify differential gene expression induced by mechanical loading.
Alternative topologies for sigma-delta modulators-a comparative study

This paper investigates four frequently used modulator topologies, namely two single-stage and two multistage architectures. Simple parametric expressions are derived which describe minimum amplifier gain and bandwidth requirements for all implementations as well as C-ratio matching conditions for the two multistage circuits. The cumulative effect of all amplifier nonidealities, including slewing, is revealed by a discrete-time simulator. This study not only presents accurate quantitative results that illustrate the negative impact of the most stringent amplifier nonidealities but also provides the necessary insight to circumvent or minimize these parasitic effects which ultimately limit performance.
Phase transitions in mesophase macromolecules. I. Novel behavior in the vitrification of poly(ethylene terephthalate‐co‐p‐oxybenzoate)

A 40:60 mole ratio poly(ethylene terephthalate-co-p-oxybenzoate) was studied by dynamic scanning calorimetry. Vitrification occurred in two steps, which could be linked by optical microscopy to a two-phase structure. For the lower glass transition, hysteresis was absent on heating and cooling through the transition temperature. Since all prior studied glasses show such hysteresis, this may be linked to the mesophase structure and raises the question whether mesophases always display such glass-transition behavior.
Factors associated with excessive daytime sleepiness in patients with severe obstructive sleep apnea

Purpose Although excessive daytime sleepiness (EDS) is one of the key symptoms of obstructive sleep apnea (OSA), associations between OSA and EDS have been inconsistent, even in patients with severe OSA. To that end, our goal was to investigate factors associated with EDS based on the Epworth Sleepiness Scale (ESS) score in a large clinical population with severe OSA (apnea–hypopnea index ≥30).
Localization of focal adhesion kinase in differentiating Schwann cell/neuron cultures

Previous studies have shown that Schwann cells (SCs) differentiate into myelin-forming or ensheathing cells only under conditions which allow the deposition of basal lamina and extracellular collagen [Bunge (1993) Peripheral Neuropathy, pp. 299-316]. SC adhesion to basal lamina is mediated by beta1 integrins and function blocking antibodies to beta1 integrins inhibit myelination [Fernandez-Valle et al. (1993) Development 119:867-880]. Recently, focal adhesion kinase (FAK), a cytoplasmic non-receptor tyrosine kinase, was found to mediate beta1 integrin-dependent signalling in a variety of cultured cell types adhering to ECM components such as fibronectin [reviewed in Schwartz et al. (1995) Ann. Rev. Cell Biol. 11:549-599; Ilic et al. (1997) J. Cell Sci. 110:401-407]. In the present study, we have determined more precisely the respective time courses of ECM deposition and myelination. In addition, we have studied by immunocytochemistry, immuno-gold labelling, and electron microscopy the expression and subcellular localization of FAK in nondifferentiating SCs and in SCs differentiating into myelinating cells. We show that the development of basal lamina and extracellular collagen fibrils precedes by 3 days the appearance of the first myelin sheaths. FAK was detected by immunocytochemistry or immuno-gold labelling only in SCs differentiating in the presence of ascorbic acid. Localization of FAK to the abaxonal plasma membrane was dependent upon ECM deposition. Cytochalasin D did not prevent or disrupt localization of FAK to the plasma membrane. These data support the possibility that FAK acts as an intermediate in the pathway by which basal lamina regulates SC differentiation.
GRASSLAND DIVERSITY AND PRODUCTIVITY: THE INTERPLAY OF RESOURCE AVAILABILITY AND PROPAGULE POOLS

Processes operating at multiple spatial scales govern the structure and functioning of ecological communities. We conducted a resource manipulation and propagule addition experiment in grassland to evaluate the interaction of local resource availability and propagule pools in governing local-scale plant colonization, biodiversity, and aboveground productivity. The availabilities of establishment microsites and water were manipulated in field plots for two years through the application of experimental soil disturbances and irrigation, respectively. Resource manipulations led to increased invasibility of the community, as predicted by the theory of fluctuating resources. Rates of colonization, enhanced by the sowing of 32 grassland species, increased plant diversity and aboveground productivity, but to a greater extent under conditions of resource enrichment. Although resource enrichment generally increased diversity and productivity, these responses were contingent upon species availability and tended to be more pronounced in the presence of an expanded propagule pool. These findings suggest that biodiversity at the level of the available propagule pool and fluctuations in resources interact to regulate local resident diversity and productivity by determining opportunities for species sorting, by mediating community assembly, and by governing the potential for functional compensation in the community.
Pleiotrophin is an abundant protein in dissociative extracts of bovine fetal epiphyseal cartilage and nasal cartilage from newborns

An abundant protein that is identical to the growth-associated protein pleiotrophin (PTN) has been isolated from dissociative extracts of bovine nasal and fetal epiphyseal cartilage. The yield from these tissues was at least 15 micrograms/g wet weight of cartilage. PTN was absent or was present only in trace amounts in mature articular cartilage. An analysis of tryptic fragments of PTN, held together with disulfide bonds, did not indicate any set pattern of cystine cross-links, which suggests a propensity for rapid refolding of the protein. PTN could not be isolated from thin (10 microns) slices of nasal cartilage in physiological extraction buffers, which indicates that it was tightly associated with the cell surface, was tightly associated with nonextractable matrix, or was an intracellular protein. Its appearance in various extraction media parallels that of histone H2b, a nucleosomal protein; this suggests a possible intracellular location for the protein. Immunohistochemical analysis of its distribution in fetal epiphysis indicated that it is associated with chondrocytes.
On signaling performance bounds of location management in next generation wireless networks

Next Generation Wireless Networks (NGWN) are proposed to achieve the goal of ubiquitous broadband networking by utilizing multiple wireless access subnetworks serving overlapping areas. Location management schemes play a very important role in NGWN since mobile users roam in coverage areas of these subnetworks simultaneously. The performance of location management schemes directly affect the overall performance of NGWN at large. In this paper, signaling performance bounds achievable by a location management scheme in the wireless portion of NGWN are presented. Assuming complete knowledge about user mobility, call arrival patterns, detailed maps of subnetworks coverage areas, and other NGWN parameters, equations for signaling performance achievable by an idealized location management scheme over the wireless interface has been derived. The performance bounds presented in this paper serve as an upper bound for the performance of any other location management scheme designed for NGWN. These bounds are intended to serve as a benchmark to determine how well a proposed location management scheme operates in NGWN and will help to determine how much room for improvement exists.
NEW SPECIMEN OF DELTATHEROIDES CRETACICUS (METATHERIA, DELTATHEROIDA) FROM THE LATE CRETACEOUS OF MONGOLIA

Abstract The holotype and only known maxillary dentition of Deltatheroides cretacicus, collected in 1925 from the Upper Cretaceous Djadokhta Formation of Bayn Dzak, Mongolia, has teeth that are badly damaged and worn, obscuring many details of their structure. Reported is a new specimen of D. cretacicus collected in 2000 from the Red Rum (Kholbot) locality near Ukhaa Tolgod, Mongolia that preserves four molars. Although the teeth are worn and have suffered some damage, they preserve details missing from the holotype. Comparisons with other deltatheroidans reveal that D. cretacicus is most similar to Deltatheridium pretrituberculare, known from Bayn Dzak, Ukhaa Tolgod, and the younger Barun Goyot Formation. In 1998, we published the first broadscale phylogenetic analysis of basal metatherians and relevant outgroups. That analysis is updated here with amendments taken from the new specimen of Deltatheroides cretacicus as well as from relevant literature appearing since our publication. As in 1998, the conse...
Near-surface flame structure characterization of simplified ammonium perchlorate/hydroxyl-terminated polybutadiene compositions

Abstract Simplified model propellant configurations, such as monomodal propellants, can be valuable in the development and validation of predictive numerical tools. These idealized experiments also yield insight into the effect of diffusion length scales on combustion, but comprehensive data covering a large range of diffusional length scales do not currently exist. Here, monomodal propellants with ammonium perchlorate (AP) particle sizes under 800 µm and AP pellets ported and filled with hydroxyl-terminated polybutadiene (HTPB) were used to systematically study the effect of diffusion length scales, or AP equivalent particle sizes) of up to 4.1 mm on flame structure. In general, burning rates increased with pressure and decreasing particle size, as expected. Burning rates for samples with particle sizes greater than 400 µm converged with AP monopropellant burning rate data above approximately 2 MPa, the AP low-pressure deflagration limit (LPDL). For a given pressure above the LPDL, burning rates eventually became constant for both increasing and decreasing particle sizes. Conversely, for a given pressure below the LPDL burning rate was shown to be a function of particle diameter. Flame structures above the composite propellants were observed using 5 kHz OH planar laser-induced fluorescence (PLIF). The transient flames were underventilated (jet-like) over the AP particles at 1 atm while lifted, inverted, and overventilated at 5 atm. Distinct diffusion flame structures were observed visually above the ported samples at 1 atm. Very luminous flames were observed at the interface between the AP and binder. The effect of strain rate on sample combustion was examined using an opposed flow burner; at 1 atm, sample burning rate was not affected by strain rate. At the largest strain rate, the sample self-extinguished after igniter shutoff, indicating that secondary diffusion flames are important in the opposed flow configuration.
What Will it Take to Retire Invasive Coronary Angiography

The techniques of cardiac catheterization and coronary angiography have changed little since their beginnings in the late 1950s. Aside from the coronary arteries, most conventional angiographic procedures have been largely replaced by computed tomography (CT) scanning, magnetic resonance imaging (
How acute total sleep loss affects the attending brain: a meta-analysis of neuroimaging studies.

Study objectives Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Design Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. Methods The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. Results The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Conclusion Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity.
The Reaction of N,4-Dinitroso-N-Methylaniline and Polymers

Abstract Both nitroso groups participate in the reaction of N,4-dinitroso-N-methyl-aniline (DNMA) with various polymers, and the pathways of the reaction are influenced by the reaction conditions. In dilute solution the rate of the reaction is proportional to the amount of unsaturation present and is pseudo-first order with respect to DNMA at elevated temperature with or without polymers present. The iV-nitroso group undergoes thermal fission liberating nitroxyl and N-methyl-p-nitrosoaniline free radicals. The presence of hydrocarbons with labile hydrogen accelerates the hydrogen abstraction by the amine free radical to form N-methyl-p-nitrosoaniline and a hydrocarbon free radical, which may combine with another amine free radical to form a hydrocarbon with pendent N-substituted-N-methyl-p-nitrosoanilme group. The 4-nitroso group of DNMA adds to the double bond, leading to the formation of an adduct with N-methyl-N-nitroso-p-phenylenediamine pendent group. Depending on the reaction conditions, the 4-nitro...
Effects of temperature and pH on growth and composition of Pythium irregulare and Pythium vexans.

Temperature and pH significantly affect the growth and composition of Pythium irregulare and P. vexans. The apparent optimum temperature for mycelial production by either fungus was lower in liquid medium than on agar, and P. irregulare produced greater amounts of mycelium than P. vexans under all conditions tested. The percentage of soluble sugar content in both fungi decreased markedly with increased incubation temperatures, whereas protein content increased. Pythium vexans contained more sugar and less protein than P. irregulare on a percentage basis. Lipid and polysaccharide content varied, but there appeared to be a balancing effect of these components with sugar metabolism. Within the ranges studied, temperature exhibited a more pronounced effect than pH on the growth and composition of these fungi.