cssi/SciSciGPT-SciSciNet huggingface dataset:
Simulation of mixed switched-capacitor/analog/digital circuits with arbitrary clocks and signals

The author describes a novel mixed-signal simulator, Spice-SCAN, for nonlinear transient analysis of SC (switched capacitor) A/D (analog-digital) circuits. Spice-SCAN partitions the input netlist into A/D and SC blocks. The A/D blocks are simulated by SPIC, while the SC blocks are simulated by SCAN with all the inputs and clocks dynamically supplied by SPICE. With this methodology there are no restrictions on the number of clocks, clock patterns, or input waveforms for the SC blocks. Any number of SC and analog/digital blocks with random interconnections are allowed. >
Effect of competing alkali metal cations on neutral Host's anion binding ability

Anion binding by neutral hosts in organic solvents can be inhibited by the presence of alkali metal cations. The binding inhibition is due to salt ion-pairing which increases in the order Cs+ < K+ < Na+. The binding inhibition can be reversed by using heteroditopic hosts that simultaneously bind both the metal cation and the anion. The largest cation-induced enhancements are observed with the less basic anions.
Simulating the effects of climate change on population connectivity of American marten (Martes americana) in the northern Rocky Mountains, USA

We utilize empirically derived estimates of landscape resistance to assess current landscape connectivity of American marten (Martes americana) in the northern Rocky Mountains, USA, and project how a warming climate may affect landscape resistance and population connectivity in the future. We evaluate the influences of five potential future temperature scenarios involving different degrees of warming. We use resistant kernel dispersal models to assess population connectivity based on full occupancy of suitable habitat in each of these hypothetical future resistance layers. We use the CDPOP model to simulate gene exchange among individual martens in each of these hypothetical future climates. We evaluate: (1) changes in the extent, connectivity and pattern of marten habitat, (2) changes in allelic richness and expected heterozygosity, and (3) changes in the range of significant positive genetic correlation within the northern Idaho marten population under each future scenario. We found that even moderate warming scenarios resulted in very large reductions in population connectivity. Calculation of genetic correlograms for each scenario indicates that climate driven changes in landscape connectivity results in decreasing range of genetic correlation, indicating more isolated and smaller genetic neighborhoods. These, in turn, resulted in substantial loss of allelic richness and reductions in expected heterozygosity. In the U.S. northern Rocky Mountains, climate change may extensively fragment marten populations to a degree that strongly reduces genetic diversity. Our results demonstrate that for species, such as the American marten, whose population connectivity is highly tied to climatic gradients, expected climate change can result in profound changes in the extent, pattern, connectivity and gene flow of populations.
Oceanography: The brawniest retroflection.

The influence of the Agulhas system of currents and eddies around southern Africa extends far beyond that region. Hence the especial need for a better understanding of the complex phenomena involved.
The dynamics of solvation in polar liquids

Abstract Recent experiments, theories, and computer simulations aimed at elucidating the dynamics of solvation in polar liquids are critically reviewed.
Lifetimes and Fluorescence Yields of States Produced in Heavy Ion-Atom Collisions

Recent theoretical results for few-electron metastable states are presented along with the experimental data. Average fluorescence yields are given for different atomic numbers.
Factors Affecting Poultry Flavor The Effect of Semi-Synthetic and Practical Type Rations on the Palatability of Broilers

Abstract A REVIEW of the literature indicates the need for research on the influence of certain feed ingredients used in formulating broiler rations on the retention and improvement of poultry flavor. Considerable work has been reported on the effect of feed ingredients in the production of off-flavor in poultry. It has been known for some time that certain fish oils and fish products may impart off-flavors to poultry according to Carrick and Hauge (1926), Marble et al. (1938), Asmundson et al. (1938) and Cruickshank (1939). Maw (1935) reported that the feeding of single grain rations resulted in corn-fed poultry being the most flavorful and moist, with barley second, oats third and wheat last. Odland, Mayfield and Page (1955) observed that broilers fed rations containing simple grain combinations of wheat and oats or wheat and barley were equal to or superior in palatability to broilers raised on rations containing more complex grain…
A model for the cinefluoroscopic and manometric study of chronic intestinal obstruction.

NFANTS BORN WITH INTESTINAL atresia have considerable dilatation of the bowel proximal to the obstruction, and the distal bowel is collapsed. When the dilated proximal intestine is anastomosed to the distal bowel, persistent functional obstruction occurs even though the anastomosis is widely patent. Contrast roentgenograms show abnormal peristalsis with a churning, to-and-fro, flow of contrast medium which is not propelled beyond the dilated part. This functional obstruction of the bowel is the most common cause of death in infants treated for jejunal atresia.’ Many investigators have studied the physiology of normal intestinal motility in the human by measuring changes in intraluminal pressure and by roentgenographic techniques. An historical summary of these methods is recorded by Hightower.’ In the small bowel, two types of intestinal contraction have been described which were derived from a correlation between intraluminal pressure changes and cinefluoroscopic observations. Type I waves are simple monophasic increases in pressure lasting less than 8 set with an amplitude of 13~ 60 cm of water pressure. These waves have been associated with eccentric contractions of the bowel wall which travel less than a few centimeters, and seem to have a mixing action on the intestinal contents. Type I waves account for 85”,, to 90”, of the wave activity in the intestine. Type III waves have a complex pattern characterized by a prolonged elevation above baseline pressure, on which are superimposed monophasic spikes similar to, but shorter in duration than Type I waves. Type III waves have been correlated with concentric contractions of the intestine which travel along the bowel wall and propel luminal contents aborally. These waves may occur every 10 set to 8 min, and have an amplitude of 5- to 30-cm water pressure. We have attempted to clarify the physiologic changes in intestinal motility after chronic small bowel obstruction. We wanted an experimental model which might be comparable to intestinal atresia, and which could be evaluated by radiologic and manometric studies. The intestinal obstruction would have to exist for several weeks or months without producing fluid or electrolyte de
Penalized-likelihood image reconstruction for x-ray fluorescence computed tomography

X-ray fluorescence computed tomography (XFCT) allows for the reconstruction of the distribution of elements within a sample from measurements of fluorescence x rays produced by irradiation of the sample with monochromatic synchrotron radiation. XFCT is not a transmission tomography modality, but rather a stimulated emission tomography modality; thus correction for attenuation of the incident and fluorescence photons is essential if accurate images are to be obtained. This is challenging because the attenuation map is, in general, known only at the stimulating beam energy and not at the various fluorescence energies of interest. We make use of empirically fitted analytic expressions for x-ray attenuation coefficients to express the unknown attenuation maps as linear combinations of known quantities and the unknown elemental concentrations of interest. We then develop an iterative image reconstruction algorithm based on penalized-likelihood methods that have been developed for medical emission tomography. Studies with numerical phantoms indicate that the approach is able to produce qualitatively and quantitatively accurate reconstructed images even in the face of severe attenuation. We also apply the method to real synchrotron-acquired data and demonstrate a marked improvement in image quality relative to filtered backprojection reconstruction.
Silylene Transfer to Allylic Sulfides: Formation of Substituted Silacyclobutanes

Silylene transfer to allylic sulfides results in a formal 1,2-sulfide migration. The rearrangement yields substituted silacyclobutanes, not the expected silacyclopropanes. The silacyclobutanes were elaborated by insertions of carbonyl compounds selectively into one carbon−silicon bond. A mechanism for the 1,2-sulfide migration is proposed involving an episulfonium ion intermediate.
An Enhanced Pulse Width Modulator with Adaptive Duty Cycle and Frequency Control

A digitally controlled pulse width modulator (PWM), targeting on-chip power management applications is proposed in this paper. A current starved ring oscillator, with digitally controlled current source based headers and footers, is used to provide a versatile duty cycle and an accurate frequency control. The proposed circuit achieves i) a controlled duty cycle that can vary between 20% and 90% and ii) a compensation circuit that guarantees a constant duty cycle under process, voltage, and temperature (PVT) variations. A fast response time of 5 ns - 20 ns with a fine duty cycle granularity has been achieved through the proposed control techniques. The circuit operates at a frequency range of 500 MHz - 1.66 GHz and is implemented with a 22 nm CMOS predictive technology model.
SU‐E‐I‐48: Cloud Computing for Interventional Fluoroscopy Dose Assessment

Purpose: To explore the application of cloud computing for quantifying and documenting patient radiation dose in interventional fluoroscopy. Methods: In this study, a framework has been developed for providing personalized Monte Carlo based dose reports for patients undergoing interventional fluoroscopic procedures. The framework is built around the DICOM Radiation Dose Structured Report (RDSR) and the ability to automatically translate the imbedded information into an input file for the MCNPXradiation transport code. A three‐step program was written to perform this task. The first step imports the RDSR and fills each row of a 2D array with the geometric and dose parameters connected to each irradiation event. The second step culls the array and summarizes the information into a limited number of irradiation events where geometric parameters for similar events are averaged and dose information summed. In the final step, each row of the summarized array is translated into an MCNPX input file by completing sections of a template file. An anthropometrically‐matched hybrid phantom selected from the UF patient‐dependent series is used to represent each patient. Initial testing was performed using twenty RDSRs received from Shands Jacksonville Medical Center. Monte Carlo simulation was executed on the ALRADS dosimetry cluster at the University of Florida, Gainesville. Results: The program successfully received twenty RDSRs via the internet and processed over 50 MCNPX input files. Detailed patient dose reports were returned on demand within 24 hours. Conclusions: While individual radiation transport is impractical within the clinic, a major technological shift has been towards internet‐based “cloud computing” where programs are run on off‐site servers accessed via the internet. In this environment and with the tools developed in this research, RDSRs can be uploaded from the clinic to the web and returned within a matter of hours as detailed radiation dose reports.
Energy gain and trapping threshold of the counterstreaming electron-beam wake-field accelerator.

The energy gain and the trapping threshold of the driven particles (protons or electrons) in the counterstreaming electron-beam wake-field accelerator (CWFA) are investigated. The CWFA relies on the same physical mechanism as the plasma wake-field accelerator (PWFA) but differs from the PWFA in that it uses a relativistic counterstreaming electron beam instead of a stationary plasma as the medium for supporting the plasma waves.
More About Polyhedra-Interpretation Through Constructions in the Image Plane

This paper deals with the interpretation and feasibility check of line drawings representing polyhedral scenes. The polyhedra are of general types and there are no restrictions on camera position. The geometric consistency check and the line labeling are carried out through constructions in the image plane. An algorithm for the geometric construction is suggested, and the necessary conditions for these constructions are discussed. The image plane construction can be used for preparing labeled junction catalogs for junctions other than trihedral. In addition the paper analyzes the relation between the image plane construction and the gradient space construction suggested by Mackworth [7] for the same purpose.
Automatic measurement of quality metrics for colonoscopy videos

Colonoscopy is the accepted screening method for detection of colorectal cancer or its precursor lesions, colorectal polyps. Indeed, colonoscopy has contributed to a decline in the number of colorectal cancer related deaths. However, not all cancers or large polyps are detected at the time of colonoscopy, and methods to investigate why this occurs are needed. We present a new computer-based method that allows automated measurement of a number of metrics that likely reflect the quality of the colonoscopic procedure. The method is based on analysis of a digitized video file created during colonoscopy, and produces information regarding insertion time, withdrawal time, images at the time of maximal intubation, the time and ratio of clear versus blurred or non-informative images, and a first estimate of effort performed by the endoscopist. As these metrics can be obtained automatically, our method allows future quality control in the day-to-day medical practice setting on a large scale. In addition, our method can be adapted to other healthcare procedures. Last but not least, our method may be useful to assess progress during colonoscopy training, or as part of endoscopic skills assessment evaluations.
Reversible Cardiac Conduction Block and Defibrillation with High-Frequency Electric Field

Electrical impulse propagation is an essential function in cardiac, skeletal muscle, and nervous tissue. Abnormalities in cardiac impulse propagation underlie lethal reentrant arrhythmias, including ventricular fibrillation. Temporary propagation block throughout the ventricular myocardium could possibly terminate these arrhythmias. Electrical stimulation has been applied to nervous tissue to cause reversible conduction block, but has not been explored sufficiently in cardiac tissue. We show that reversible propagation block can be achieved in cardiac tissue by holding myocardial cells in a refractory state for a designated period of time by applying a sustained sinusoidal high-frequency alternating current (HFAC); in doing so, reentrant arrhythmias are terminated. We demonstrate proof of concept using several models, including optically mapped monolayers of neonatal rat ventricular cardiomyocytes, Langendorff-perfused guinea pig and rabbit hearts, intact anesthetized adult rabbits, and computer simulations of whole-heart impulse propagation. HFAC may be an effective and potentially safer alternative to direct current application, currently used to treat ventricular fibrillation.
Initiation of Surface and Interface Edge Cracks in Functionally Graded Ceramic Thermal Barrier Coatings

The initiation of surface and interface edge cracks in functionally graded ceramic thermal barrier coatings resulting from the application of a thermal load is studied. For a given specimen configuration, the singular behavior of the thermal stresses is analytically determined in terms of a singularity power {beta} and pseudo-stress intensity factors K{sub 1} and K{sub 2}. Crack initiation at the surface at the interface is related to the surface temperature and the temperature difference between the surface of the coating and the substrate. The experimental results are used to provide Weibull curves for the probability of survival of plasma sprayed mullite and CoCrAlY coating systems.
A universal numerical treatment of radiative transport equations with differential and integral scattering operators

An investigation of the normal incidence of an infinite plane wave on a slab of uniformly scattering media is undertaken using the PN -method. We demonstrate the computational competitiveness of the PN -method, not only in its ability to provide timely solutions even for strongly anisotropic scattering (g > 0.9), but also in its ability to simultaneously treat various theories of scattering such as the Henyey- Greenstein model, the Fokker-Planck forward scattering approximation using the Laplace-Beltrami operator, and the Leakeas-Larsen rational approximation. We also discuss the extendibility of the method to the study of backscatter and transmission due to normally incident collimated pencil beam illumination.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Activity Tolerance After Periacetabular Osteotomy

Background:Periacetabular osteotomy is a well-described surgical intervention for symptomatic acetabular deformities in skeletally mature patients. Data regarding return to athletic activity or sport after this procedure are still limited.Purpose:To evaluate the ability of patients to return to preoperative levels of activity after periacetabular osteotomy.Study Design:Case series; Level of evidence, 4.Methods:This is a retrospective review of active patients treated with periacetabular osteotomy for acetabular deformity correction. Patients were identified as those with preoperative University of California–Los Angeles activity levels ≥7. Patient demographics, operative data, radiographic measures, and clinical outcomes were documented prospectively. The University of California–Los Angeles activity score, Harris Hip Score, Hip Dysfunction and Osteoarthritis Outcome Score, and Western Ontario and McMaster Universities Osteoarthritis Index were used to measure clinical outcomes, and details regarding acti...
Accumulation of nitrotyrosine on the SERCA2a isoform of SR Ca-ATPase of rat skeletal muscle during aging: a peroxynitrite-mediated process?

The SR Ca-ATPase in skeletal muscle SR vesicles isolated from young adult (5 months) and aged (28 months) rats was analyzed for nitrotyrosine. Only the SERCA2a isoform contained significant amounts with approximately one and four nitrotyrosine residues per young and old Ca-ATPase, respectively. The in vitro exposure of SR vesicles of young rats to peroxynitrite yielded selective nitration of the SERCA2a Ca-ATPase even in the presence of excess SERCA1a. No nitration was observed during the exposure of SR vesicles to nitric oxide in the presence of O2. These data suggest the in vivo presence of peroxynitrite in skeletal muscle. The greater nitrotyrosine content of SERCA2a from aged tissue imolies an age-associated increase in susceptibility to oxidation by this species.
Purification and properties of a leukemic cell phosphodiesterase

Abstract A phosphodiesterase has been partially purified from extracts of mouse leukemic cells (L4946) carried as an ascitic tumor. Purified fractions resemble snake venom phosphodiesterase in forming nucleoside 5′-phosphates from RNA, from polymers synthesized with polynucleotide phosphorylase, and from oligonucleotides as small as a dinucleotide. As with venom, the cleavage appears to be stepwise by splitting off a single mononucleotide unit at a time from an end of the chain. However, in contrast to the venom enzyme, the leukemic cell phosphodiesterase is unable to hydrolyze simple benzyl or p-nitrophenyl esters of nucleoside 5′-phosphates. It thus belongs to a new class of phosphodiesterases with a specificity requiring that two nucleoside moieties must be in ester linkage to a phosphate group. The rates of hydrolysis of different polynucleotides differ very widely.
A myb gene required for leaf trichome differentiation in Arabidopsis is expressed in stipules

The GL1 gene is required for the initiation of differentiation of hair cells (trichomes) on the crucifer, Arabidopsis thaliana. This gene has been localized to a 4.5 kb DNA fragment by molecular complementation of gl1 mutants. DNA sequence analysis has shown that the protein encoded by GL1 contains a Myb DNA-binding motif. Southern analysis and subsequence analysis of isolated lambda clones has established that GL1 is a member of an extensive myb gene family in Arabidopsis. The putative GL1 promoter directs the expression of the GUS reporter gene in non-trichome-bearing structures that appear to be stipules. This pattern of expression suggests that GL1 may control the synthesis of a diffusible signal that activates the developmental pathway for trichome differentiation.
Résultats des bouchons vasculaires d'Amplatz pour occlusion des artères iliaques internes au cours des endoprothèses pour anévrysme aorto-iliaque

Nous rapportons les resultats des bouchons vasculaires d'Amplatz (BVA) pour occlusion de l'artere iliaque interne (AII) au cours de la mise en place des endoprotheses pour anevrysme aorto-iliaque et anevrysme isole de l'artere iliaque commune. Nous avons etudie retrospectivement 10 malades traites a l'aide d'un BVA unique de l'AII par endoprothese du segment siege d'un anevrysme degeneratif. L'imagerie a comporte une arteriographie conventionnelle avant et apres deploiement ainsi qu'une tomodensitometrie (TDM) avec injection de produit de contraste avant et apres la procedure. De plus, la tolerance subjective a l'exercice avant et apres procedure a egalement ete etudiee, une attention particuliere etant portee a la presence ou a l'absence d'une claudication fessiere. La mise en place precise du BVA dans le tronc principal de l'AII a ete realisee dans tous les cas en utilisant une approche standard “par le haut” tout en maintenant la permeabilite du tronc distal et des deux branches de division de l'AII. Aucune endofuite de type II par le BVA n'a ete notee en per-operatoire ou sur les TDM au cours du suivi. La claudication fessiere etait absente chez tous les malades sauf un, dont les symptomes ont disparu a 6 semaines. Le dispositif BVA peut etre utilise comme alternative aux coils pour occlure l'AII lors du traitement endovasculaire des anevrysmes aorto-iliaques. La precision du deploiement de ce dispositif permet une preservation satisfaisante de la bifurcation de l'AII et peut donc permettre la preservation d'un important flux pelvien collateral.
Negotiations, superstitions, and the plight of individuals born with severe birth defects

Abstract Belief in superstition in relationship to the plight of the individual born with a severe birth defect is discussed. Three major teratogenic theories: Omens and Divination, Hybridity (Human-animal, human-devil) and maternal image (direct and indirect) are reviewed, and a negotiation oriented approach involving individuals, society and supernatural beings, is applied to these theories. It is hypothesized that negotiations between individuals and supernatural beings occur in two major forms that have differing social significance. (1) The “private pact” initiated by individuals between themselves and a deity. This type of negotiation tends to act as “insurance” in an attempt to obtain an outcome that is highly valued and over which the human partners feel that they have too little control, e.g. the birth of a normal baby. (2) The “societal pact” that sets proper behavioral standards for members of society. In this type, the birth of a congenital anomaly is usually used as ex-post facto evidence of transgression of the limits of acceptable behavior.
Instabilities in the Mechanical Stress in Deposited SiO2 Films Caused by Thermal Treatments

Using an in-situ stress measurement technique that measures stress as a function of annealing temperature, instabilities in mechanical stress induced by heat treatment in a variety of doped/undoped SiO2 films deposited by APCVD, LPCVD and PECVD techniques have been investigated. A large hysteresis in mechanical stress, caused by first heat treatment to which the as-deposited films are subjected, has been observed in films deposited by APCVD/LPCVD techniques. No such hysteresis is obsesrved in films deposited by PECVD technique. Hysteresis in APCVD/LPCVD films is found to vanish once the films are heat treated at or above 800°C. The results are discussed in terms of oxide densification, the presence of hydrogenous species, and phosphorous.
Methods Of Photoelectric Astrometry

The idea of a photoelectric technique applied to differential astrometry has been around for about a decade. When developed such instruments promise increased accuracy and speed. Using linear detectors they can determine relative magnitudes and colors of all stars in the field at the same time that the relative positions are measured. Three such instruments have been proposed and have been developed to various degrees. These instruments and several variants will be reviewed. The current status of one instrument employing a rotating Ronchi linear grid, called the AMAS, will be discussed in detail. An accuracy of 5 μm in position is achieved routinely and proposed improvements project an improvement of a factor of ten to 0.5 μm. At this point the accuracy will be "seeing" limited and further improvement will be at the expense of observing time. The present instrument is sky limited at a magnitude of 11.5(V). A very minor change will increase this limit to 15.5(V) using two minute integration periods.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Visual cortex operations and their implementation using the incoherent optical neuron model.

The incoherent optical neuron model uses two different device responses, an inhibitory response and a nonlinear output response, to realize a complete neuron unit that has both inhibitory and excitatory inputs. We describe its use to implement a model of simple cells of the visual cortex. Such simple cells perform the operations of edge detection, orientation selection, and in the case of moving objects, direction and speed selection. Experiments are described that utilize two Hughes liquid-crystal light valves to perform the functions of input transduction and optical neuron unit-array implementation. A multiplexed dichromated gelatin hologram serves as a holographic optical element that forms space-invariant (but otherwise arbitrary) point-spread functions for the network interconnections. Changing the holographic interconnection pattern permits implementation of different simple cells performing, e.g., transient response, edge detection, orientation preference, and direction and speed preference. Experimental results of these operations are presented.
Damage-plasticity in a uniaxially loaded composite lamina: Overall analysis

The initiation and evolution of damage and elasto-plastic deformation in composite laminae is studied using an overall approach. In this approach, one damage tensor is used to describe damage in composite materials including the initiation, growth, and coalescence of voids and cracks in the matrix, fiber fracture, and debonding. The mathematical formulation is derived using vectors and matrices to keep the mathematics accessible to many readers who may not be familiar with tensor analysis. The model is applied to a thin fiber-reinforced unidirectional composite lamina subjected to uniaxial tension. This problem is selected in order to demonstrate how the model can be used without resorting to the finite element method. A governing system of nine simultaneous ordinary differential equations is established for this problem based on the overall approach to damage in composite materials. The system is solved numerically and the results are discussed.
Vigilance for Cutaneous and Auditory Stimuli as a Function of Intersignal Interval and Signal Strength

Abstract : Vigilance for infrequent auditory or electrical cutaneous stimuli at both weak and moderate intensities was investigated. Detection probability was very high for moderate intensity signals and weak auditory stimuli. Errors significantly increased with time on task for faint cutaneous signals. Increase of the intersignal interval significantly increased the number of errors. An explanation of the results is suggested in terms of greater habituation for weak or relatively infrequent signals.
The use of multi-criteria assessment in developing a process model

Abstract Ecological data frequently contain multiple patterns. A process model of the system producing the data should be able to recreate those patterns. We describe a method and associated software where components of the pattern are used as multiple criteria to assess a model during its construction. Successive improvements are made to the model so that it describes more components of the pattern effectively. The software, Pareto_Evolve is an evolutionary algorithm. Initially it creates many individual sets of model parameters, each is used in the model to produce results that are then compared to patterns in a data set. Different individuals may achieve different components of the pattern and Pareto_Evolve calculates those that are most effective and uses them to produce new individuals. This is done by changing parameter values of individuals, called mutation, or exchanging parameter values between individuals, called crossover. This process is repeated over many generations so that a most effective parameterization evolves. We illustrate this method with a model for hourly increments of extension of the leading shoot of a conifer tree. The particular task here is to model water uptake by the plant in response to water loss due to transpiration, calculate a water deficit between uptake and loss, and calculate contraction and re-expansion of shoot tissue due to diurnal changes in tissue water deficit. We choose criteria corresponding to different phases in the diurnal pattern of expansion and model for up to six consecutive days. A value is set marking the limit within which the model must achieve the criteria for it to be judged as success. This value is called a binary discrepancy measure. Pareto_Evolve is used to make multiple searches with successively smaller binary discrepancy measures until all criteria are no longer achieved. At this point different parameter sets achieve different groups of criteria and we use these as indicators of how the structure of the model must be improved to achieve an overall better fit. In our example we find that contraction is more rapid than re-expansion, which is a hysteresis effect, and that re-expansion of tissue continues after water deficit within the tissue is estimated to have been removed. We discuss how this method can be used in model development and particularly how multiple criteria assessment can be used in model development.
New insights into pancreatic cancer-induced paraneoplastic diabetes

Up to 85% of patients with pancreatic cancer have diabetes or hyperglycaemia, which frequently manifests as early as 2-3 years before a diagnosis of pancreatic cancer. Conversely, patients with new-onset diabetes have a 5-8-fold increased risk of being diagnosed with pancreatic cancer within 1-3 years of developing diabetes. Emerging evidence now indicates that pancreatic cancer causes diabetes. As in type 2 diabetes, β-cell dysfunction and peripheral insulin resistance are seen in pancreatic cancer-induced diabetes. However, unlike in patients with type 2 diabetes, glucose control worsens in patients with pancreatic cancer in the face of ongoing, often profound, weight loss. Diabetes and weight loss, which precede cachexia onset by several months, are paraneoplastic phenomena induced by pancreatic cancer. Although the pathogenesis of these pancreatic cancer-induced metabolic alterations is only beginning to be understood, these are likely mechanisms to promote the survival and growth of pancreatic cancer in a hostile and highly desmoplastic microenvironment. Interestingly, these metabolic changes could enable early diagnosis of pancreatic cancer, if they can be distinguished from the ones that occur in patients with type 2 diabetes. One such possible biomarker is adrenomedullin, which is a potential mediator of β-cell dysfunction in pancreatic cancer-induced diabetes.
Properties of visual interneurons in a deep-sea mysid, Gnathophausia ingens

Adult Gnathophausia ingens, a bioluminescent deep-sea mysid, were collected off the California coast and brought, protected from the light, to the Marine Laboratory of the University of California, Santa Barbara (UCSB) for single-unit recordings of afferent visual interneurons. These units, which traverse the optic stalk, were classified according to their response to light stimuli varying in intensity, duration and area. The most common were sustaining fibers responding throughout a continuous stimulus. The only other type, “on” fibers, showed a transient response without reference to stimulus movement. Sustaining fibers responded to irradiances as low as, 2.7×103 photons cm-2s-1sr-1, and were characterized by long temporal summations and large receptive fields. These are characteristics of a visual system adapted for maximizing sensitivity. However, the transient response of the “on” fibers also suggests a capability to react to rapidly changing light sources such as bioluminescence, a matter of importance since this mysid requires dietary coelenterazine to sustain its luminescent system.
Difference equations, isoperimetric inequality and transience of certain random walks

The difference Laplacian on a square lattice in Rn has been stud- ied by many authors. In this paper an analogous difference operator is studied for an arbitrary graph. It is shown that many properties of the Laplacian in the continuous setting (e.g. the maximum principle, the Harnack inequality, and Cheeger's bound for the lowest eigenvalue) hold for this difference oper- ator. The difference Laplacian governs the random walk on a graph, just as the Laplace operator governs the Brownian motion. As an application of the theory of the difference Laplacian, it is shown that the random walk on a class of graphs is transient. The random walks we consider are defined as follows. Let K be a connected graph (i.e. a one dimensional simplicial complex). For a vertex x E K, let m(x) denote the number of edges emanating from x. The probability that a particle moves from x to another vertex y E K is l/m(x) if x and y are connected by an edge and it is zero otherwise. As observed by Courant, Friedrichs and Lewy (CFL) for the case of a square lattice in the plane this random walk is intimately related to the difference analog of the Laplacian
CHILDREN'S SLEEPWEAR CONTROVERSY: DATA FROM A BURN UNIT

Recent publicity about the possible carcinogenicity of “TRIS,” used in some flame-resistant children's sleepwear, questions the value of the July, 1973, federal regulations regarding the flammability of children's sleepwear, sizes 0-6x. In a 3-½ year period (Jan.'70-June'73), 29 children under 7 years of age were treated at the SBI for injuries sustained by the ignition of their sleepwear in ways other than in house fires; during a later period of identical length (July'73-Dec.'76), 11 children were treated for injuries sustained in this manner. (Total acute admissions, earlier period: 309; later period: 317.) Most accidents involved momentary contact with an ignition source: stoves (18), matches/cigarette lighters (15), candles (3), heaters (2), other (2). The behavior of children in these situations was contrary to those which would minimize harm. Most children ran, the result being flame spread and more extensive burns. Children's sleepwear, sizes 7-14, has been regulated in Massachusetts since Dec.'73. From 1970-1973, there were 11 non-house fire sleepwear admissions of children, ages 7-14; from 1974-1976, there were 5. The decline in such sleepwear admissions for all ages is marked: 1974=10 cases; 1975=3 cases; 1976=1 case. Of these cases, only one (1976) involved flame-resistant pajamas; that patient received a comparatively small burn. Further, three children who received their burns in night-time house fires demonstrated the considerable protective characteristics of flame-resistant sleepwear.
Organizational Culture and Institutional Theory: A Conversation at the Border

The article of record as published may be found at http://dx.doi.org/10.1177/1056492611419790
Specificity of trail markers of forest and eastern tent caterpillars

Exploratory trails deposited on paper strips by the forest tent caterpillar (FTC),Malacosoma disstria Hubner, and the eastern tent caterpillar (ETC),M. americanum (Fabricius), as well as extracts of these trails, readily elicited interspecific trail-following behavior. In 2-choice tests involving simple Y mazes constructed from these paper strips, the caterpillars of both species preferred by approximately 3∶1 the trails of the FTC. Studies involving whole colonies of the ETC maintained under nearnatural conditions in the laboratory, however, indicated that the trails deposited by successful foragers of the ETC as they returned to their tent from feeding sites were more attractive than the exploratory trails of either the ETC or FTC. The pronounced interspecific response of these congeners to each other's trails suggests that they utilize either qualitatively similar or identical trail-marking chemicals. Both species preferred their own trails to those ofArchips cerasivoranus (Fitch) (Tortricidae), providing the first evidence that more distantly related lepidopterous larvae utilize distinct trails.
Trap efficiency of reservoirs

Forty-four records of reservoir trap efficiency and the factors affecting trap efficiency are analyzed. The capacity-inflow (C/I) ratio is found to offer a much closer correlation with trap efficiency than the capacity-watershed (C/W) ratio heretofore widely used. It appears likely from the cases studied that accurate timing of venting or sluicing operations to intercept gravity underflows can treble or quadruple the amount of sediment discharged from a reservoir. Desilting basins, because of their shape and method of operation, may have trap efficiencies above 90 pct even with very low C/I ratios. Semi-dry reservoirs with high C/I ratios, like John Martin Reservoir, may have trap efficiencies as low as 60 pct. Truly “dry” reservoirs, such as those in the Miami Conservancy District, probably have trap efficiencies in the 10 to 40 pct range, depending upon C/I ratio
Organisation of microtubules and actin filaments in the cortex of differentiating Selaginella guard cells

Using fluorescent probes and confocal laser scanning microscopy we have examined the organisation of the microtubule and actin components of the cytoskeleton in kidney-shaped guard cells of six species of Selaginella. The stomata of Selaginella exhibit novel cytoskeletal arrangements, and at different developmental stages, display similarities in microtubule organisation to the two major types of stomata: grass (dumbbell-shaped) and non-grass (kidney-shaped). Initially, cortical microtubules and F-actin radiate from the stomatal pore and extend across the external and internal periclinal cell surfaces of the guard cells. As the stomata differentiate, the cytoskeleton reorients only along the internal periclinal walls. Reorganisation is synchronous in guard cells of the same stoma. Microtubules on the inner periclinal walls of the guard cells now emanate from areas of the ventral wall on either side of the pore and form concentric circles around the pore. The rearrangement of F-actin is similar to that of microtubules although F-actin is less well organised. Radial arrays of both microtubules and F-actin are maintained adjacent to the external surfaces. Subsequently, in two of the six species of Selaginella examined, microtubules on both the internal and external walls become oriented longitudinally and exhibit no association with the ventral wall. In the other four species, microtubules adjacent to the internal walls revert to the initial radial alignment. These findings may have implications in the development and evolution of the stomatal complex.
Effects of noninvasive transcutaneous electrical stimulation via concentric ring electrodes on pilocarpine-induced status epilepticus in rats.

Summary Purpose: The aim of this pilot study was to investigate the antiepileptic effects of a novel noninvasive stimulation technique, transcutaneous electrical stimulation (TcES) via scalp concentric ring electrodes, on pilocarpine-induced status epilepticus (SE) in rats. Methods: Five minutes after the onset of SE, TcES was administered to the experimental rat via bipolar concentric ring electrode at the CZ location. Symmetrical, biphasic, charge-balanced, constant current, isolated pulses were applied via a custom-made stimulator. TcES parameters ranged from 200–750 Hz, 200 or 300 μs pulse duration, and 50 or 60 mA, applied for 1 min, started with the least intense parameter set and progressively increased. Results: TcES attenuated electrographic seizure activity and halted the progression of behavioral seizures. Interruption of seizure activity outlasted the period of stimulation and appeared to be long-lasting. TcES treatment significantly extended the life and enhanced the survival of rats after SE. Conclusions: Noninvasive TcES, applied 5 min after SE onset via novel concentric ring electrodes on the scalp, reduced, or abolished electrographic and behavioral seizure activity in pilocarpine-induced SE in rats. These findings suggest that TcES may have a role in the treatment of SE.
Prolonged postpartum proteinuria after early preeclampsia

r d i l m m n d m a m ( r p ARLY PREECLAMPSIA may result from or be associated with a pre-existing, unrecgnized renal disease.1,2 Compared to patients ith late-onset preeclampsia, patients with early reeclampsia have a higher prevalence of undiagosed renal disease and a higher risk for subseuent development of chronic hypertension.3-5 A arge study that defined “early onset” preeclampia as occurring before 37 weeks of gestation ompared 55 patients with early onset disease to 6 patients with late onset.6 Early-onset preclamptic patients had a higher incidence of rimary renal disease (65% versus 17%, respecively), and the most common biopsy finding was gA nephropathy.6 Thus, early onset of preeclampia is a marker of underlying renal disease in the ajority of affected patients. Proteinuria is a common manifestation of both reeclampsia and primary renal disease. Howver, the time course for the resolution of proteinria following parturition may provide insight nto its pathogenesis. In 1 study, 37 of 42 preclamptic women (88%) had complete resoluion of proteinuria within 6 weeks following elivery and only 1 continued to have proteinuria
B7-1 Engagement of Cytotoxic T Lymphocyte Antigen 4 Inhibits T Cell Activation in the Absence of CD28

Ligation of cytotoxic T lymphocyte antigen 4 (CTLA4) appears to inhibit T cell responses. Four mechanisms have been proposed to explain the inhibitory activity of CTLA4: competition for B7-1 and B7-2 binding by CD28; sequestration of signaling molecules away from CD28 via endocytosis; delivery of a signal that antagonizes a CD28 signal; and delivery of a signal that antagonizes a T cell receptor (TCR) signal. As three of these potential mechanisms involve functional antagonism of CD28, an experimental model was designed to determine whether CTLA4 could inhibit T cell function in the absence of CD28. TCR transgenic/recombinase activating gene 2–deficient/CD28–wild-type or CD28-deficient mice were generated and immunized with an antigen-expressing tumor. Primed T cells from both types of mice produced cytokines and proliferated in response to stimulator cells lacking B7 expression. However, whereas the response of CD28+/+ T cells was augmented by costimulation with B7-1, the response of the CD28−/− T cells was strongly inhibited. This inhibition was reversed by monoclonal antibody against B7-1 or CTLA4. Thus, CTLA4 can potently inhibit T cell activation in the absence of CD28, indicating that antagonism of a TCR-mediated signal is sufficient to explain the inhibitory effect of CTLA4.
Role of Systemic Agrobacterium tumefaciens Populations in Crown Gall Incidence on the Walnut Hybrid Rootstock ‘Paradox’

Abstract Greater than 75% of English walnut production in the United States occurs on the walnut rootstock Juglans hindsii × J. regia ‘Paradox’, which is highly susceptible to infection by Agrobacterium tumefaciens. When seed were germinated and grown in the presence of A. tumefaciens, in the absence of wounding, 94% of the seedlings exhibited tumors while 89% contained systemic A. tumefaciens populations. When seedlings were wound inoculated, A. tumefaciens established endophytic populations in stem tissue and often migrated from the site of infection. Distribution of A. tumefaciens in the stem was random and may exhibit seasonal variation. A. tumefaciens populations in root tissue were more readily detected than in stem tissue and may serve as a reservoir for subsequent infection of the aerial portions of the tree. Importantly, 7% of inoculated, asymptomatic seedlings contained endophytic populations of A. tumefaciens. In all, 17% of seedlings inoculated as seeds developed galls at secondary stem-wound ...
A SIMS study of the interaction of potassium carbonate with carbon black

Abstract Secondary ion mass spectrometry combined with isotopic labeling has been applied to study the interaction of potassium carbonate (K 2 C 18 O 3 ) with carbon black ( 13 C) at 300–1500 K. The SIMS analysis shows that K 2 CO 3 decomposes above 800 K to form K 2 O, which subsequently decomposes at 1070 K. A K 2 O surface species was identified by SIMS at all the temperatures studied. The presence of K 2 O before K 2 CO 3 thermally decomposes is attributed to the presence of H 2 O in the original sample, and a model is presented to explain K 2 O formation.
Relationship between peripheral blood lymphocytes and their functional capacity in sarcoidosis.

Abstract Sarcoidosis is a disease of unknown etiology characterized by granuloma formation in tissues and anergy to delayed hypersensitivity. In 34 sarcoidosis patients and 16 normal persons, T cells from peripheral blood were quantitated and their functional capacity assessed by sheep red blood cell (SRBC) rosette assay and mitogen response, respectively. Effect of Kveim-Siltzbach suspension (KSS) on rosette formation and its ability to induce blast formation were also examined. Normal spleen cell suspension (NSS) was used as control. The results show that 84% of patients had suppressed T-cell numbers, while 79% had suppression of both active (rosettes formed immediately on incubation with SRBC) and total (rosettes formed after a 1-hr incubation on ice) T cells. Mean active was 30% in sarcoidosis patients vs 44% in controls, while mean total was 48% in sarcoidosis patients vs 64% in controls, while mean total was 48% in sarcoidosis patients vs 64% in control subjects. Suppressed mitogen response to phytohemagglutinin was seen in only 34% of patients and of this number, 90% had decreased T-cell numbers (active and total), suggesting that T-cell suppression does not necessarily reflect functional abnormality in these cells; however, the reverse is true. KSS caused no blastogenesis or change in rosette formation when incubated with lymphocytes from sarcoid patients (KSS active 36%; total 48%: NSS active 34%; total 48%). Either the cells are insensitive to KSS stimulation or sensitive cells have migrated to sites of granuloma formation.