cssi/SciSciGPT-SciSciNet huggingface dataset:
Autologous stem cell transplantation in two children with disabling pansclerotic morphea

Background Disabling pansclerotic morphea is an extremely rare and severe disorder in children, systemic treatment with corticosteroids and methotrexate (MTX) or mycophenolate mofetil (MMF) are the most common therapies. However, patients can develop severe disabilities. Autologous stem cell transplantion (ASCT) is a successful treatment option for systemic scleroderma and might also be beneficial for severe therapy resistant disabling pansclerotic morphea.
SCATTERING AND DIFFRACTION OF LIGHT BY PARTICLES IN PLANETARY REGOLITHS

Abstract The nature of diffraction and scattering by particles in planetary regoliths is discussed. It is pointed out that the Percus–Yevick approximation to the particle radial distribution function is not valid for a regolith, so that structure factor models based on it are incorrect. A simple analytic expression, valid for general shape and size distributions, for the decrease in scattering cross section caused by the proximity of other particles is derived. It is shown that the classical diffraction pattern of an isolated particle does not exist in a regolith, and that the diffracted light is indistinguishable from the incident irradiance. Hence, to an excellent approximation diffracted light may be treated as unscattered. It is shown that back scattering particles are common in nature and that this conclusion is consistent with the theoretical models published in the paper by Mishchenko and Macke (JQSRT, 1997, 57, 767). It is demonstrated that when exact solutions of the radiative transfer equation are used to analyze observational data sets with a small range of phase angles they retrieve particle asymmetry parameters that are erroneously negative, but that if the range is sufficiently large, approximate reflectance models retrieve correctly positive asymmetries. Hence, assertions that approximate models retrieve erroneously negative asymmetries are false. However, most laboratory and planetary observations are poorly suited to constrain the particle scattering properties in the forward direction, so that many planetary regoliths may have particle phase functions with forward scattering lobes, in addition to back scattering ones. It is pointed out that the radiative transfer equation has inherent deficiencies that make it intrinsically incapable of calculating exact descriptions of scattering by a close-packed regolith of large particles and also that the accuracies of typical absolute reflectance measurements are not high. For both reasons it is pointless to be overly concerned with the relative accuracies of exact and approximate regolith scattering models based on the equation of radiative transfer.
Flow estimate for an artificial upwelling in the sea

Abstract An order-of-magnitude calculation of the limiting efficiency of an artificial heat source in producing a vertical oceanic current is suggested. An estimate by Groves then permits interpretation of upward flow rate of deep nutrient-rich water in terms of edible fish production rate near the surface. The latter quantity is found to be small for very large artificial heat sources.
From Creutzfeldt-Jakob disease to the mad cow epidemic

Hans-Gerhard Creutzfeldt and Alfons Jakob independently authored clinical and pathologic descriptions of a new syndrome in the 1920s. This syndrome, which subsequently came to be named after them, was characterized by dementia, motor and coordination abnormalities, a fatal course, and pathologic findings of diffuse spongiform neuronal degeneration. Although it appeared for many years to be little more than a medical curiosity, Creutzfeldt-Jakob disease attained widespread attention by its pathologic similarity to kuru and bovine spongiform encephalopathy, "mad cow disease." Because there are sporadic, familial, and iatrogenic forms of Creutzfeldt-Jakob disease, it is considered to have both genetic and infectious aspects. Although its causation has for some time been ascribed to "slow viruses," the etiology of Creutzfeldt-Jakob disease is currently thought to be due to prions, small proteinaceous infectious particles that have genetic encoding. The debate regarding whether the appearance of atypical Creutzfeldt-Jakob disease can be linked to the epidemic of "mad cow disease" is currently unresolved.
Statistical models for estimating fatigue strain-life behavior of pressure boundary materials in light water reactor environments

The existing fatigue strain versus life (S-N) data for materials used in nuclear power plant components have been compiled and categorized according to material, loading and environmental conditions. Statistical models have been developed for estimating the effects of the various service conditions on the fatigue life of these materials. The results have been used to estimate the probability of initiating a fatigue crack. Data in the literature were reviewed to evaluate the effects of the size, geometry and surface finish of a component on its fatigue life. Fatigue S-N curves for components have been determined by adjusting the probability distribution curves of smooth test specimens for the effect of mean stress and then applying design margins to account for the uncertainties that arise because of component size, geometry and surface finish. The significance of the effect of the environment on the current code design curve and on the proposed interim design curves published in NUREG/CR-5999 is discussed. Estimations of the probability of fatigue cracking in sample components from boiling water reactors and pressurized water reactors are presented.
Distributed simulation: creating distributed simulation using DEVS M&S environments

We briefly review the theory of modeling and simulation and its support for constructing distributed simulations. Formal representation of simulation models can contribute to a number of aspects in the modeling and simulation enterprise. Separation of models from simulation execution engines is a prerequisite transferring model among phases of a project as well as from project to project. The Discrete Event System Specification (DEVS) formalism, drawing on its system theoretic basis, provides a number of important properties such as hierarchical, modular composition, universality and uniqueness that can support development of simulation models and environments their development. An layered architecture for supporting comprehensive M&S environments is discussed that unifies the theoretical framework with implementation in distributed computational environments.
Color Coding Stereo Pairs For Non-Interlaced Displays

We describe a method for coding color stereo pair images for display on non-interlaced displays. The display frame buffer has a single frame memory and a single output lookup table. Left and right views are coded together as one picture, such that a pixel in the main frame memory is an index into two colormaps. Switching between left and right views is accomplished by changing the color lookup table during each vertical retrace. The color stereo pair can then be viewed by the use of a polarized display with passive glasses. Such a coding scheme compares favorably with systems that use alternate picture lines for left and right views, or with systems that divide the single bitmap in half.
The Incorporation of a Photoisomerizable Amino Acid into Proteins in E. coli

An orthogonal aminoacyl tRNA synthetase/tRNA pair has been evolved that allows the incorporation of the photoisomerizable amino acid phenylalanine-4'-azobenzene (AzoPhe) into proteins in E. coli in response to the amber nonsense codon. Further, we show that AzoPhe can be used to photoregulate the binding affinity of catabolite activator protein to its promoter. The ability to selectively incorporate AzoPhe into proteins at defined sites should make it possible to regulate a variety of biological processes with light, including enzyme, receptor, and ion channel activity.
Targeted Inactivation of Mdm2 RING Finger E3 Ubiquitin Ligase Activity in the Mouse Reveals Mechanistic Insights into p53 Regulation

Summary It is believed that Mdm2 suppresses p53 in two ways: transcriptional inhibition by direct binding, and degradation via its E3 ligase activity. To study these functions physiologically, we generated mice bearing a single-residue substitution (C462A) abolishing the E3 function without affecting p53 binding. Unexpectedly, homozygous mutant mice died before E7.5, and deletion of p53 rescued the lethality. Furthermore, reintroducing a switchable p53 by crossing with p53ER TAM mice surprisingly demonstrated that the mutant Mdm2 C462A was rapidly degraded in a manner indistinguishable from that of the wild-type Mdm2. Hence, our data indicate that (1) the Mdm2-p53 physical interaction, without Mdm2-mediated p53 ubiquitination, cannot control p53 activity sufficiently to allow early mouse embryonic development, and (2) Mdm2's E3 function is not required for Mdm2 degradation.
Porokeratotic eccrine ostial and dermal duct nevus: A case report and review of the literature

Hamartomas with eccrine differentiation are quite rare. There are 5 accepted classifications: eccrine nevus, eccrine-centered nevus, eccrine angiomatous hamartoma, eccrine syringofibroadenoma, and porokeratotic eccrine ostial and dermal duct nevus. The latter, PEODDN, typically presents as congenital keratotic papules and plaques located on the distal extremities. We report a classic case of PEODDN that was localized to the left hand since early childhood. The literature on this rare benign tumor is also reviewed.
Isolation and characterization of periaxolemmal and axolemmal enriched membrane fractions from the rat central nervous system.

In this report, we describe the fractionation of crude axolemmal fractions from rat lower brainstem into subfractions enriched in markers for either periaxolemmal myelin or axolemma. These subfractions were isolated on density gradients as bands layering on 0.8M and 1.0M sucrose. Both subfractions consisted of unilamellar vesicles. Relative to myelin purified from the same starting material, the 0.8M subfraction was enriched in MAG, CNPase, carbonic anhydrase and Na+, K+ ATPase but was extremely low in PLP and MBP. In addition, this fraction exhibited a protein profile distinct from myelin. The 1.0M fraction was also highly enriched in Na+, K+ ATPase and had an overall composition similar to the 0.8M subfraction. However, it differed from the 0.8M subfraction by being low in MAG, CNPase, and carbonic anhydrase, but enriched in voltage-dependent Na+ channel, axon-specific fodrin, and MAP-1B. Based on these characteristics we concluded that the 0.8M and 1.0M subfractions were highly enriched in periaxolemmal myelin and axolemmal membrane, respectively. Plasmolipin10 was unique with equally high levels in myelin and in the 0.8M and 1.0M subfractions. Both subfractions were enriched, relative to myelin, in the alpha subunit of the GTP binding protein, Go, and the alpha subunit common to all G proteins, GA/1. Electrophysiology with membrane subfractions fused to lipid bilayers showed that both membranes contained sets of K+ and Cl− channels, which based on channel sizes and open times, are largely distinct from one another. © 1992 Wiley-Liss, Inc.
Practical pathology for thermal tissue applications

The development of minimally invasive medical devices, which employ hyperthermic and/or cryothermic modalities to treat a variety of organ system diseases, is a rapidly expanding field. Consultation with a knowledgeable pathologist during the development of these devices is crucial, as characterization of the treated tissues can support the device’s safety and future efficacy. The properties of thermally treated tissues often share a set of overlapping histopathologic characteristics, regardless of organ system. Several methods for optimally evaluating these thermal changes have been developed that depend on the tissue’s post-treatment time interval. For devices associated with hyperthermic collagen denaturation, bright field or polarized light microscopy of hematoxylin and eosin stained sections can be utilized to assess thermal spread within the tissue. For applications resulting in collagen denaturation with associated desiccation, trichrome staining may provide additional information. For cryothermic devices, these collagen-based methods are generally less informative. Tetrazolium-based tissue viability staining (triphenyltetrazolium chloride, TTC; nitroblue tetrazolium, NBT; NADH/NADPH staining) can be used to assess for the presence of associated tissue necrosis within either hyperthermically or cryothermically treated tissues. The advantages and limitations of several of these methods will be discussed.
In-flight digital image analysis of sprinkler drops

Understanding the process of sprinkler droplet formation and behavior while in flight is crucial to the improvement of water and chemical application by sprinkler irrigation. A relatively simple and inexpensive method is presented which allows in-flight characterization of irregularly shaped liquid droplets and ligaments produced by irrigation sprinkler devices. A high-speed photographic image acquisition probe was constructed to allow nonintrusive, direct investigation of water jet breakup, drop formation and behavior, size, and shape of monodispersed drops at various locations from the nozzle. Image contrast and motion freezing was accomplished by backlighting the liquid particles with a 1.5 microsecond(s) duration stroboscope. High resolution film allowed analysis over a wide range of particle sizes (0.3 mm to 50 mm). Image processing and analysis was performed on digitized images using commercially available software. This software provided geometrical size and shape parameters of the breakup fragments and allowed discrimination between in and out-of-focus drops by post analysis. Applications of the method included: studying the effect of wind direction and speed, nozzle type, and pressure on sprinkler jet breakup.
Extensive aspartoacylase expression in the rat central nervous system.

Aspartoacylase (ASPA) catalyzes deacetylation of N-acetylaspartate (NAA) to generate acetate and aspartate. Mutations in the gene for ASPA lead to reduced acetate availability in the CNS during development resulting in the fatal leukodystrophy Canavan disease. Highly specific polyclonal antibodies to ASPA were used to examine CNS expression in adult rats. In white matter ASPA expression was associated with oligodendrocyte cell bodies, nuclei and some processes, but showed a dissimilar distribution pattern to myelin basic protein and oligodendrocyte specific protein. Microglia expressed ASPA in all CNS regions examined, as did epiplexus cells of the choroid plexus. Pial and ependymal cells and some endothelial cells were ASPA positive, as were unidentified cellular nuclei throughout the CNS. Astrocytes did not express ASPA in their cytoplasm. In some fiber pathways and nerves, particularly in the brainstem and spinal cord, the axoplasm of many neuronal fibers expressed ASPA, as did some neurons. Acetyl coenzyme A synthase immunoreactivity was also observed in the axoplasm of many of the same fiber pathways and nerves. All ASPA-immunoreactive elements were unstained in brain sections from tremor rats, an ASPA-null mutant. The strong expression of ASPA in oligodendrocyte cell bodies is consistent with a lipogenic role in myelination. Strong ASPA expression in cell nuclei is consistent with a role for NAA-derived acetate in nuclear acetylation reactions, including histone acetylation. Expression of ASPA in microglia may indicate a role in lipid synthesis in these cells, whereas expression in axons suggests that some neurons can both synthesize and catabolize NAA.
Individual Investor Mutual-Fund Flows

Abstract This paper studies the relation between individuals’ mutual fund flows and fund characteristics, establishing three key results. First, consistent with tax motivations, individual investors are reluctant to sell mutual funds that have appreciated in value and are willing to sell losing funds. Second, individuals pay attention to investment costs as redemption decisions are sensitive to both expense ratios and loads. Third, individuals’ fund-level inflows and outflows are sensitive to performance, but in different ways. Inflows are related only to “relative” performance, suggesting that new money chases the best performers in an objective. Outflows are related only to “absolute” fund performance, the relevant benchmark for taxes.
Reactions in cluster-surface collisions.

We provide the first report of a reaction process occurring during the collision between a cluster and a solid surface. Scattering of alkali fluoride clusters composed of >60 atoms from silicon at hyperthermal energies (0.1-0.5 eV/atom) leads to efficient F - transfer reactions. The reaction probability approaches one-half for large clusters and newly etched Si(111)-H, following heating to desorb hydrogen. The abrupt size threshold implicates a collective mechanism, such as a shock wave in the impacting cluster
Precision Measurements By Optical Heterodyne Techniques

Detection systems with high sensitivity are of interest in all fields of science and engineering. No exception to this generality is the desire to be able to detect small absorptions or phase shifts of an optical beam, whether that be for detection of weak absorp tion of dilute atomic or molecular systems or for detecting small length changes in optical cavities for gravity wave research, etc. The past 15 years have seen the development of a number of good techniques for enhancing sensitivity in the detection of such perturbations to an optical beam. Almost invariably the high sensitivity detectors are laser-based systems, for example: direct subtraction of intensity fluctuations1 removal of intensity fluctuations by active control,2 laser intracavity absorption,3 derivative spectroscopy, polarization spectroscopy,4 intermodulation techniques,5 interferometric spectroscopy,6 polinex,7 heterodyne-detected Raman spectroscopy,8 etc. There are other techniques with high sensitivity which do not observe the optical beam directly but rather observe the effects of absorption from the optical beam, for instance fluorescence detection,9 optogalvanic spectroscopyl10 and opto-acoustic spectroscopy.11 Most of the methods, by some means, try to suppress the background noise which is not inherent on the signal.
What determines the number of ovarioles in a fly ovary

Abstract The relation between the size of a fly and the number of ovarioles in its ovary was investigated in Phormia regina and Sarcophaga bullata. Small flies of varying size were produced by taking larvae prematurely off the food. The smallest flies thus obtained were derived from larvae only 1 8 of the weight of a normal larva. The number of ovarioles in an ovary is directly proportional to the size of the fly and, in the extreme case, is about 1 5 the normal number in Sarcophaga and about 1 3 in Phormia. Larvae prematurely taken off the food, but fed again after starving for several days, grow to normal or almost normal size and develop ovaries with about the normal number of ovarioles. Small or re-fed Sarcophaga do not show any changes in the anatomy of individual ovarioles but in Phormia disorders in ovariole development and a consequent reduction of fertility are frequent. The number of ovarioles remains identical from the early pupal stage all through the development of the pharate fly and then through ovarian development in the adult fly: it is determined by the size of the larva when it was taken off the food. This shows that it is not lack of space in a small adult fly abdomen which determines the number nor the occurrence of degenerative processes during ovarian development.
Groupthink and the Gulf Crisis

‘Groupthink’ refers to a situation in which decision makers seek to achieve concurrence among group members more than to make calculated, carefully considered decisions. In this study, the theory is explored in the case of the 1990–91 Persian Gulf crisis, with particular emphasis on President George Bush's inner circle. Using rare interviews and primary sources, it is revealed that some important conditions of the theory were present that affected how decisions were made, and it is explained theoretically why the outcome was none the less positive, contrary to what the theory would seem to predict.
Preparation and characterization of iron(III) oxide films by a novel spray pyrolysis method

Abstract α-Fe2O3 thin films were deposited on silicon substrates by nebulization of a 0.01 M solution of iron acetylacetonate in a 50% methanol/water mixture followed by pyrolysis and annealing in flowing oxygen. The resulting films were characterized by X-ray diffraction, scanning electron microscopy, and their electrical transport behavior. The IR transmission spectrum of α-Fe2O3 recorded from such films agreed with published theoretical analysis based on the crystal structure.
A divide-and-merge methodology for clustering

We present a divide-and-merge methodology for clustering a set of objects that combines a top-down “divide” phase with a bottom-up “merge” phase. In contrast, previous algorithms use either top-down or bottom-up methods to construct a hierarchical clustering or produce a flat clustering using local search (e.g., k-means). For the divide phase, which produces a tree whose leaves are the elements of the set, we suggest an efficient spectral algorithm. When the data is in the form of a sparse document-term matrix, we show how to modify the algorithm so that it maintains sparsity and runs in linear space. The merge phase quickly finds the optimal partition that respects the tree for many natural objective functions, for example, k-means, min-diameter, min-sum, correlation clustering, etc. We present a thorough experimental evaluation of the methodology. We describe the implementation of a meta-search engine that uses this methodology to cluster results from web searches. We also give comparative empirical results on several real datasets.
Nonlinear dynamics of ladder and lambda STIRAP

Abstract We have studied the exact nonlinear dynamics underlying stimulated Raman adiabatic passage (STIRAP) for a particle in a multi-level anharmonic system (the infinite square-well) driven by two sequential laser pulses, each with constant carrier frequency. We compare two basic processes, ladder and lambda. We have found that the coherent population transfer for both cases is dependent on the nature of the Floquet eigenphase avoided crossings created by an underlying transition to chaos.
An argument concerning quantification and propositional attitudes

These are perfectly ordinary, garden variety English sentences. They mark a clear contrast, one which Quine taught us to pay attention to.' A sentence like (1) attributes a belief merely that there is a thing of a certain kind. There may be no particular thing of that kind that she has in mind. Many different restaurants might make Hollie's belief true. (2), on the other hand, says there is some particular restaurant about which she has an opinion. The qualities of that restaurant alone determine the truth of her belief. If you are interested in eating Chinese tonight, you might get in touch with Hollie because (2) is true, but not because of (1). Many different kinds of sentence can be used to say the sort of thing that (2) says, that is, that someone has some belief about some particular thing. These sentences are all similar in that they involve linguistic cross reference from within the scope of a propositional attitude verb to an antecedent outside of that context. In (2) the cross reference is by way of the absent subject of the contained sentence. In the familiar languages of logic the cross reference is accomplished by a variable bound by a quantifier outside the propositional attitude
Fluorescent Porous Polymer Films as TNT Chemosensors: Electronic and Structural Effects

The synthesis, spectroscopy, and fluorescence quenching behavior of pentiptycene-derived phenyleneethynylene polymers, 1−3, are reported. The incorporation of rigid three-dimensional pentiptycene moieties into conjugated polymer backbones offers several design advantages for solid-state (thin film) fluorescent sensory materials. First, they prevent π-stacking of the polymer backbones and thereby maintain high fluorescence quantum yields and spectroscopic stability in thin films. Second, reduced interpolymer interactions dramatically enhance the solubility of polymers 1−3 relative to other poly(phenyleneethynylenes). Third, the cavities generated between adjacent polymers are sufficiently large to allow diffusion of small organic molecules into the films. These advantages are apparent from comparisons of the spectroscopic and fluorescence quenching behavior of 1−3 to a related planar electron-rich polymer 4. The fluorescence attenuation (quenching) of polymer films upon exposure to analytes depends on seve...
Do nitrates differ

1. The organic nitrates all share a common biochemical and physiological mechanism of action. 2. The organic nitrates differ substantially in their pharmacologic potency and pharmacokinetics. In vitro potency differences appear larger than the corresponding in vivo activities. 3. The duration of action of organic nitrates, after a single immediate-release dose, is governed by the pharmacokinetics of the drug. However, the duration of action of available sustained-release preparations, whatever the nitrate or formulation, is limited to about 12 h, due to the development of pharmacologic tolerance. 4. Nitrates do not appear to differ in their production of undesirable effects.
Posterior inferior cerebellar artery to posterior inferior cerebellar artery in situ bypass for the treatment of Bow hunter's-type dynamic ischemia in holovertebral dissection.

Background Bow hunter's syndrome is a rare cause of vertebrobasilar insufficiency arising from mechanical compression of the vertebral artery (VA) during rotation of the head. Surgical treatment usually involves direct decompression of the VA at the site of compression. We describe what is to our knowledge the first reported case of a posterior inferior cerebellar artery (PICA)-to-PICA in situ bypass for treatment of Bow hunter's-type ischemia in a patient with a VA dissection. Case Description The patient was a 41-year-old man who developed disabling symptoms of vertebrobasilar insufficiency after trauma when he rotated his head to the right. Dynamic angiography demonstrated a chronic dissection and stasis of flow in the right VA when his head was rotated to the right, with no obvious site of focal compression. The right VA ended in the PICA and the left VA was of good caliber. A single-photon emission computed tomography study with acetazolamide challenge confirmed brainstem ischemia and poor cerebrovascular reserve. He ultimately underwent a PICA-to-PICA in situ bypass to revascularize his right PICA territory with complete symptom resolution. Conclusions The PICA-to-PICA in situ bypass is a useful option in the treatment of Bow hunter's-type ischemia in the absence of focal structural compression of the VA or VA stenosis.
Determination of Silicon Dioxide in Silicon Carbide by Photoacoustic Infrared Fourier Transform Spectrometry

Advanced ceramics are being investigated quite actively. The characterization of the materials used to make the ceramics is important to final product performance. We have previously reported an application of diffuse reflectance infrared Fourier transform (DRIFT) spectrometry to the determination of silicon dioxide (SiO2) in silicon carbide (SiC). The DRIFT technique was found to have a simpler application than that of transmission techniques, for the analysis of powdered solids, because DRIFT does not require the sample preparation of KBr disks or mineral oil mulls. However, the scattering caused by the analyte powder surface requires dilution of the SiC powder with KBr fine powder, to avoid distortion of the diffuse refractance spectrum. For quantitative work, this dilution requires accurate weighing and perfect mixing.
Simulating the effect of flow path roughness to examine how green infrastructure restores urban runoff timing and magnitude

Abstract Impervious land cover was the choice for many urban development projects in order to accelerate runoff and reduce the depth and duration of local flooding, however this led to increases in downstream runoff characterized by large, flashy peak flows. Urban ecosystem restoration now involves slowing down urban runoff to restore local hydrology with green infrastructure, which can be installed as single parcels along runoff flow paths; green infrastructure essentially increases the surface roughness, delaying the speed of runoff compared with relatively smooth impervious surfaces. In this study, we present a runoff routing model that inter-compares runoff from different land parcel surfaces with different roughness to help communities quantify how land parcel restoration impacts runoff timing and peak magnitude. Our modeling experiments contrast the timing and magnitude of floods for discrete runoff pathways composed of parcels with different cover types, converting rough rural land cover to smooth impervious cover as well as the restorative impact of relocating impervious area further from the water body or installing green infrastructure along the flow path. We demonstrate how the model is calibrated to match observed runoff for an entire watershed, and how the model can then be used to estimate how land cover changes will affect runoff timing and magnitude. This study introduces how a simple model to represent land parcel surface roughness and stormwater runoff timing and magnitude, allowing for informed watershed restoration planning, urban planning and placement of green infrastructure.
Stress intensity factors and COD in an orthotropic strip

The elasticity problem for an orthotropic strip or a beam with an internal or an edge crack under general loading conditions is considered. The numerical results are given for four basic loading conditions, namely, uniform tension, pure bending, three point bending, and concentrated surface shear loading. For the strip with an edge crack additional results regarding the crack opening displacements are obtained by using the plastic strip model. A critical quantity which is tabulated is the maximum compressive stress in the plane of the crack. It is shown that this stress may easily exceed the yield limit in compression and hence may severely limit the range of application of the plasticity results.
Antigen–Antibody ż Bands in the Micro-Double-Diffusion Agar Technique

MANY useful variations of immunodiffusion techniques have been reported1. In particular the micro-adaptation has gained wide usage, and the utilization of thiazine red dye to stain the bands after completion of the reaction has helped make the lines visible2. Yet, after extensive use of these modifications in attempts to reveal anti-spermatogenic antibodies in the sera and tissues of aspermatogenic guinea pigs, our results have been disappointing. First, lines of precipitation, were only rarely seen, and when they were observed, they were so faint or faded so rapidly as to instil doubt of their reality. Secondly, the use of thiazine red or other stains in the recommended manner did not improve the visibility or preservation of the lines.
The Body-Machine Interface: A New Perspective on an Old Theme

Body-machine interfaces establish a way to interact with a variety of devices, allowing their users to extend the limits of their performance. Recent advances in this field, ranging from computer interfaces to bionic limbs, have had important consequences for people with movement disorders. The authors provide an overview of the basic concepts underlying the body-machine interface with special emphasis on their use for rehabilitation and for operating assistive devices. They outline the steps involved in building such an interface and highlight the critical role of body-machine interfaces in addressing theoretical issues in motor control as well as their utility in movement rehabilitation.
Extrahepatic tissue copper concentrations in white perch with hepatic copper storage

Hepatic copper storage in man (Wilson's disease), Bedtington and West Highland white terriers, and white perch (Morone americana) is characterized by the progressive accumulation of copper in hepatic lysosomes bound to cytoprotective metallothionein. In man, saturation of the liver storage capacity results in the distribution of copper to extrahepatic tissues with multiple organ system dysfunction. To determine if extrahepatic tissue copper concentrations also increase in white perch, copper and zinc levels in liver, brain, heart, gills, serum, and bile were determined by atomic absorption spectrophotometry and compared to striped bass (Morone saxatilis). Results showed that brain copper concentrations in. white perch were elevated and significantly correlated with liver copper. Bile and serum copper also increased significantly with liver copper. Copper levels in heart and gill tissues were low. Liver zinc was increased in white perch but not to the same magnitude as copper, and was correlated significantly with liver copper; possibly a non-specific secondary increase related to an overall increase in hepatic metallothionein. Histochemical staining of liver with rubeimc acid for copper was proportional to copper concentrations, and clusters of positive mononuclear cells were also seen in brain and spleen. Foci of macrophages in spleen were also intensely positive with Perl's iron stain which may have been indicative of haemolysis. The patterns of copper distribution seen in white perch present a useful comparative model to study alterations in copper metabolism.
Influence of extracellular polysaccharides on the toxicity of copper and cadmium towardKlebsiella aerogenes.

Many investigations have reported the effects of heavy metals on pure cultures of bacteria (14, 21, 30), algae (3, 22, 25), and on natural microbial populations (1, 2, 17). Most of the studies have focused on copper toxicity because copper sulfate has been used as an algicide since the turn of the century (3, 22, 24, 25). The assessment of the toxicity of heavy metals toward microorganisms must take into account the physicochemical parameters of the water (17, 23, 24) and the presence of chelators in natural waters. Natural (humic acids, amino acids, polypeptides) and artificial (EDTA, Nitroloacetate) chelators form organic complexes with metallic ions and thus alter the availability of these toxic metals to aquatic microorganisms (10, 19, 20, 24, 28). Microorganisms are known to produce large quantities of extracellular polysaccharides which are organized in well-defined capsules around the cells, or are excreted as loose materials into the growth medium. The ecological significance of these polymetric materials has been previously discussed (13, 15, 27). However, among the various functions assigned to extracellular polysaccharides, their ability to bind metallic ions has received little attention (11, 26). In this study we report the effect of capsular polysaccharides on copper and cadmium toxicity toward Klebsiella aerogenes. This particular bacterium was chosen because we had a noncapsulated mutant which could be compared to the encapsulated strain.
Topics in Design Automation Data Bases

Within the last few years more and more organizations are using data base technology to manage large amounts of information. Design automation organizations are no exception. This paper discusses the application of data base technology to the field of design automation. This includes an examination of file versus data base management systems; control and integrity of design automation data; and the impact of data bases on design automation and corporate organization.
Testosterone response to courtship predicts future paternal behavior in the California mouse, Peromyscus californicus

In the monogamous and biparental California mouse (Peromyscus californicus), paternal care is critical for maximal offspring survival. Animals form pair bonds and do not engage in extrapair matings, and thus female evaluation of paternal quality during courtship is likely to be advantageous. We hypothesized that male endocrine or behavioral response to courtship interactions would be predictive of future paternal behavior. To test this hypothesis, we formed 20 pairs of California mice, and evaluated their behavior during the first hour of courtship interactions and again following the birth of young. We also collected blood from males at baseline, 1 hr after pairing, 3 weeks paired, and when young were 4 days old to measure testosterone (T). We found that male T-response to courtship interactions predicted future paternal behavior, specifically the amount of time he huddled over young when challenged by the temporary removal of his mate. Males that mounted T increases at courtship also approached pups more quickly during this challenge than males who had a significant decrease in T at courtship. Proximity of the male and female during courtship predicted paternal huddling during a 1-hr observation, and a multiple regression analysis revealed that courtship behavior was also predictive of birth latency. We speculate that male T-response to a female in P. californicus is an honest indicator of paternal quality, and if detectable by females could provide a basis for evaluation during mate choice.
Net Primary Production and Canopy Nitrogen in a Temperate Forest Landscape: An Analysis Using Imaging Spectroscopy, Modeling and Field Data

Understanding spatial patterns of net primary production (NPP) is central to the study of terrestrial ecosystems, but efforts are frequently hampered by a lack of spatial information regarding factors such as nitrogen availability and site history. Here, we examined the degree to which canopy nitrogen can serve as an indicator of patterns of NPP at the Bartlett Experimental Forest in New Hampshire by linking canopy nitrogen estimates from two high spectral resolution remote sensing instruments with field measurements and an ecosystem model. Predicted NPP across the study area ranged from less than 700 g m−2 year−1 to greater than 1300 g m−2 year−1 with a mean of 951 g m−2 year−1. Spatial patterns corresponded with elevation, species composition and historical forest management, all of which were reflected in patterns of canopy nitrogen. The relationship between production and elevation was nonlinear, with an increase from low- to mid-elevation deciduous stands, followed by a decline in upper-elevation areas dominated by evergreens. This pattern was also evident in field measurements and mirrored an elevational trend in foliar N concentrations. The increase in production from low-to mid-elevation deciduous stands runs counter to the generally accepted pattern for the northeastern U.S. region, and suggests an importance of moisture limitations in lower-elevation forests. Field measurements of foliar N, wood production and leaf litterfall were also used to evaluate sources of error in model estimates and to determine how predictions are affected by different methods of acquiring foliar N input data. The accuracy of predictions generated from remotely sensed foliar N approached that of predictions driven by field-measured foliar N. Predictions based on the more common approach of using aggregated foliar N for individual cover types showed reasonable agreement in terms of the overall mean, but were in poor agreement on a plot-by-plot basis. Collectively, these results suggest that variation in foliar N exerts an important control on landscape-level spatial patterns and can serve as an integrator of other underlying factors that influence forest growth rates.
Glycine insertion in the hinge region of lactose repressor protein alters DNA binding.

Amino acid alterations were designed at the C terminus of the hinge segment (amino acids ∼51–59) that links two functional domains within lactose repressor protein (LacI). Gly was introduced between Gly58 and Lys59 to generate Gly58+1; Gln60 was changed to Gly or Pro, and up to three additional glycines were inserted following Gln60 → Gly. All mutant proteins exhibited purification behavior, CD spectra, assembly state, and inducer binding properties similar to wild-type LacI and only small differences in trypsin proteolysis patterns. In contrast, significant differences were observed in DNA binding properties. Gly58+1 exhibited a decrease of ∼100-fold in affinity for O1 operator, and sequential Gly insertion C-terminal to Gln60 → Gly resulted in progressively decreased affinity for O1operator, approaching nonspecific levels for insertion of ≥2 glycines. Where sufficient affinity for O1 operator existed, decreased binding to O1 in the presence of inducer indicated no disruption in the allosteric response for these proteins. Collectively, these results indicate that flexibility and/or spacing between the core and N-terminal domains did not significantly affect folding or assembly, but these alterations in the hinge domain profoundly altered affinity of the lactose repressor protein for its wild-type target sequence.
Three-axis attitude control for solar-powered electric propulsion spacecraft

Spacecraft utilizing solar electric propulsion (SEP) for certain long-term interplanetary missions will depend on large, flexible solar arrays. The resulting spacecraft configurations present some complex flight control problems. Questions regarding a general design approach are discussed along with options for three-axis control forces, tradeoffs for three-axis control forces, controllers for SEP attitude control, sensors for SEP attitude control, aspects of nonrigid vehicle interaction with attitude control, thrust vector control SEP dynamics, and mass expulsion control SEP dynamics. It is found that the state-of-the-art of control system design is mature enough to support an SEP project.
Spontaneous pneumothorax after shoulder arthroscopy: A report of four cases

This article reviews four cases of spontaneous pneumothorax that occurred after shoulder arthroscopy. Each of the patients had an underlying history of smoking or asthma. The cause was believed to be a rupture of an underlying bleb or bullae. No other complications were identified with the cases such as faulty equipment or anesthesia problems.
Linking biodiversity to ecosystem function: implications for conservation ecology

We evaluate the empirical and theoretical support for the hypothesis that a large proportion of native species richness is required to maximize ecosystem stability and sustain function. This assessment is important for conservation strategies because sustenance of ecosystem functions has been used as an argument for the conservation of species. If ecosystem functions are sustained at relatively low species richness, then arguing for the conservation of ecosystem function, no matter how important in its own right, does not strongly argue for the conservation of species. Additionally, for this to be a strong conservation argument the link between species diversity and ecosystem functions of value to the human community must be clear. We review the empirical literature to quantify the support for two hypotheses: (1) species richness is positively correlated with ecosystem function, and (2) ecosystem functions do not saturate at low species richness relative to the observed or experimental diversity. Few empirical studies demonstrate improved function at high levels of species richness. Second, we analyze recent theoretical models in order to estimate the level of species richness required to maintain ecosystem function. Again we find that, within a single trophic level, most mathematical models predict saturation of ecosystem function at a low proportion of local species richness. We also analyze a theoretical model linking species number to ecosystem stability. This model predicts that species richness beyond the first few species does not typically increase ecosystem stability. One reason that high species richness may not contribute significantly to function or stability is that most communities are characterized by strong dominance such that a few species provide the vast majority of the community biomass. Rapid turnover of species may rescue the concept that diversity leads to maximum function and stability. The role of turnover in ecosystem function and stability has not been investigated. Despite the recent rush to embrace the linkage between biodiversity and ecosystem function, we find little support for the hypothesis that there is a strong dependence of ecosystem function on the full complement of diversity within sites. Given this observation, the conservation community should take a cautious view of endorsing this linkage as a model to promote conservation goals.
Temporally robust relay sets for mobile wireless networks

Existing relay set election algorithms used for self-organizing mobile ad hoc network (MANET) [1] routing control and data forwarding are often designed to continuously minimize the relay set at topological snapshots in time. Due to errors in wireless link sensing and the potential for significant neighbor adjacency fluctuation, present distributed relay set election algorithms can cause significant reelection churn for a unicast or multicast routing protocol since the algorithm is attempting to optimize the relay set for each topological instance. This paper illustrates an investigation of improvements in temporal robustness by minimizing reelection churn caused by these algorithms. In this paper several existing relay set election algorithms are compared. This includes presentation of performance results in time when undergoing increasing congestion and dynamics due to mobility. Simple techniques designed to improve the temporal stability of the relay set population undergoing significant dynamics are presented and tested. Initial results from modeling demonstrating that temporal robustness improvement to these algorithms is achievable and that more work is needed to understand the tradeoffs, such as the additional network overhead required to achieve stability and the effect of different styles of link fluctuation and topological dynamics.
Subfemtosecond pulses in the multicascade stimulated Raman scattering

We explore recently predicted multifrequency 2π solitons in multicascade stimulated Raman scattering (SRS) that was mode locked by the dynamics of population at a Raman quantum transition; we show that these solitons are eigensolitons of a general solitary-wave solution. Soliton components at each frequency are bright pulses of the same (Lorentzian) shape, in contrast to the familiar bright–dark soliton pair in regular SRS and to 1/cosh regular 2π solitons. Coherent interference of these components gives rise to a train of well-resolved subfemtosecond pulses. From an observation viewpoint the simplest SRS 2π solitons are so-called bright–bright solitons in noncascade SRS with either two (laser + Stokes) or three (e.g., laser + Stokes + anti-Stokes) components.
Using GaN FETs for High Power RF Switches

GaN FET technology is facilitating the development of a new level of high power solid state switching performance. FET switches are now obtaining RF power handling levels comparable and even exceeding conventional PIN and mechanical switches up thru microwave frequencies while still offering the traditional advantages common to GaAs switches.
Access to medical care for low-income persons: how do communities make a difference?

This paper considers the impact of community-level variables over and above the effects of individual characteristics on healthcare acess for low-income children and adults residing in large metropolitan statistical areas (MSAs). Further, we rank MSAs’ performance in promoting healthcare access for their low-income populations. The individual-level data come from the 1995 and 1996 National Health Interview Survey (NHIS). The community-level variables are derived from multiple public-use data sources. The out-come variable is whether low-income individuals received a physician visit in the past twelve months. The proportion receiving a visit by MSA varied from 63% to 99% for children and from 62% to 83% for adults. Access was better for individuals with health insurance and a regular source of care and for those living in communities with more federally-funded health centers. Children residing in MSA