cssi/SciSciGPT-SciSciNet huggingface dataset:
Transversely isotropic elastic properties of single-walled carbon nanotubes

While it is known that the elastic properties of a single-walled carbon nanotube (SWNT) are transversely isotropic, the closed-form solutions for all five independent elastic moduli have not been solved completely. In this paper, an energy approach in the framework of molecular mechanics is used to evaluate the local and global deformations of a SWNT in a unified manner. This is carried out under four loading conditions: axial tension, torsional moment, in-plane biaxial tension, and in-plane pure shear, respectively, from which the closed-form expressions for the longitudinal Young's modulus, major Poisson's ratio, longitudinal shear, plane strain bulk, and in-plane shear moduli are obtained. It is shown that as the tube diameter increases, the major Poisson's ratio approaches a constant, the longitudinal Young's and shear moduli and the plane strain bulk modulus are inversely proportional to the tube diameter, and the in-plane shear modulus is inversely proportional to the third power of the tube diameter. The dependence of the elastic moduli of a SWNT on the tube diameter and helicity is displayed and discussed.
Ocular inflammatory disease in patients with polymyalgia rheumatica: A case series and review of the literature

Scleritis and uveitis are potentially blinding conditions that can be associated with systemic inflammatory diseases. Polymyalgia rheumatica (PMR) is a common rheumatic disorder of the elderly of uncertain etiology. Although there are a few published reports of scleritis and uveitis in PMR patients, the association of PMR to ocular inflammation has not been well established. The aim of this study is to report a series of PMR patients with scleritis and/or uveitis and review the prior published reports of this potential association. We retrospectively reviewed the medical charts of patients with PMR and scleritis or uveitis who were examined in the Ocular Immunology Service of Massachusetts Eye and Ear Infirmary. We also performed a systematic literature search (PubMed; January 1990 until January 2014) to identify earlier published reports. Seven PMR patients with ocular inflammatory disease (OID) were included in our study: two with scleritis, three with anterior uveitis, and two with panuveitis. The onset of PMR preceded the occurrence of OID in six patients, and in one patient uveitis developed 2 months prior to PMR. Five patients demonstrated a temporal association between flares of PMR and OID. In four patients, OID flares developed during tapering of systemic prednisone prescribed for PMR. Four of the five patients who had relapsing PMR had recurrent or persistent uveitis over the course of follow-up. PMR may be associated with both scleritis and uveitis and should be considered as a possible underlying cause of OID.
Micromechanics-based thermoelastic model for functionally graded particulate materials with particle interactions

Thermoelastic behavior of functionally graded particulate materials is investigated with a micromechanical approach. Based on a special representative volume element constructed to represent the graded microstructure of a macroscopic material point, the relation between the averaged strains of the particle and matrix phases is derived with pair-wise particle interactions, and a set of governing equations for the thermoelastic behavior of functionally graded materials is presented. The effective coefficient of thermal expansion at a material point is solved through the overall averaged strain of two phases induced by temperature change under the stress-free condition, and is shown to exhibit a weak anisotropy due to the particle interactions within the graded microstructure. When the material gradient is eliminated, the proposed model predicts the effective coefficient of thermal expansion for uniform composites as expected. If the particle interactions are disregarded, the proposed model recovers the Kerner model. The proposed semi-analytical scheme is consistent and general, and can handle any thermal loading variation. As examples, the thermal stress distributions of graded thermal barrier coatings are solved for two types of thermal loading: uniform temperature change and steady-state heat conduction in the gradation direction.
Digital imaging in pathology--current applications and challenges

Conventional histopathology is rapidly shifting towards digital integration. Will microscopes (and pathologists) soon be obsolete? Or are we dealing with just another image modality that leaves the core of tissue diagnosis intact? This article provides an overview of current digital pathology applications and research with emphasis on whole slide imaging (WSI). Static or interactive digital pathology work stations already can be used for many purposes, e.g. telepathology expert consultations, frozen section diagnosis in remote areas, cytology screening, quality assurance, diagnostic validations for clinical trials, quantitation of hormone receptor or HER2 studies in breast cancer, or three-dimensional visualization of anatomical structures, among others. Changes of workflow in histology laboratories are beginning to enable digital image acquisition and WSI in a routine setting. WSI plays an increasing role in pathology education, glass slide boxes in medical schools are being replaced by digital slide collections; digital slide seminars and virtual microscopy are used for postgraduate and continuing medical education in pathology. Research and efforts to validate WSI systems for diagnostic settings are ongoing.
TIME RESOLVED SPECTROSCOPIC STUDIES ON THE INTACT HUMAN LENS

Abstract— The human lens is continually under photooxidative stress from ambient radiation. In the young lens the major absorbing (between300–400 nm) species is the glucoside of 3-hydroxy kynurenine. Using time resolved fluorescence spectroscopy on both the isolated compound and the intact human lens, the first excited singlet state of this compound is shown to have fast (ps) decay processes. This would tend to minimize damage to lens constituents because there would be little time for energy transfer into more harmful channels. Thus, this compound appears to act as a protection for the retina. With aging, human lens proteins become yellow with absorptions out to 450 nm. Time resolved diffuse reflectance spectroscopic studies on intact older human lenses showed that excitation (355 nm) resulted in the formation of long lived (microseconds) transient species with an absorption maximum at ca 490 nm. Similar spectra were obtained from two model systems used to explain age related changes in human lens proteins.
A study of the abrasive wear of pure metals using a pin-on-drum apparatus☆

Abstract As a part of an investigation of the mechanisms of abrasive wear, the Bureau of Mines, U.S. Department of the Interior, has made a further study of the proposed linear relationship between abrasion resistance and hardness for pure metals, using samples of known purity and grain size. Two different types of abrasive cloth were used for the tests and were found to have little effect on results. It is further demonstrated that abrasion resistance usually correlates better with the hardness of worn or otherwise work-hardened specimens than with the hardness of unworn, annealed specimens, and that the correlation improves when it is restricted to metals of the same crystal structure. The present results are in reasonable agreement with those of previous studies.
Effect of Storage Conditions and Chemical Treatments on Firmness, in Vitro Protein Digestibility, Condensed Tannins, Phytic Acid and Divalent Cations of Cooked Black Beans (Phaseolus vulgaris)

Black beans stored at 30° or 40°C and 80% relative humidity showed marked increases in firmness and decreases in in vitro digestibility of proteins. Changes in these properties were small when beans were stored at 5°C and 50% relative humidity. The adverse effects of poor storage conditions could be practically eliminated by soaking beans in salt solutions instead of water. The changes in firmness and digestibility were accompanied by changes in the detectable concentrations of tannins and phytates. Protein digestibility appears to be reduced by interactions between protein and tannins, especially high molecular weight tannins. Concentration of these tannins is affected by poly-phenol oxidase activity. Firmness increased and protein digestibility decreased as the phytic acid content decreased.
VARIABLE STEP SIZE DESTABILIZES THE STORMER/LEAPFROG /VERLET METHOD*

For fixed step-sizeh the Stormer method is stable for the standard test equationy=ω2y,ω>0, if and only ifhω<2. We show that for variable step sizehn there does not exist a (positive) limit onhω which ensures stability. Nor can we guarantee stability if, in addition, we limit the step size ratiohn/hn−1.
Unsolved problems in observational astronomy. II. Focus on rapid response – mining the sky with “thinking” telescopes

The existence of rapidly slewing robotic telescopes and fast alert distribution via the Internet is revolutionizing our capability to study the physics of fast astrophysical transients. But the salient challenge that optical time domain surveys must conquer is mining the torrent of data to recognize important transients in a scene full of normal variations. Humans simply do not have the attention span, memory, or reaction time required to recognize fast transients and rapidly respond. Autonomous robotic instrumentation with the ability to extract pertinent information from the data stream in real time will therefore be essential for recognizing transients and commanding rapid follow-up observations while the ephemeral behavior is still present. Here we discuss how the development and integration of three technologies: (1) robotic telescope networks; (2) machine learning; and (3) advanced database technology, can enable the construction of smart robotic telescopes, which we loosely call “thinking” telescopes, capable of mining the sky in real time. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Aluminum incorporation in stishovite

[1] First-principles calculations of the structure, energetics, compressibility, and elastic constants of aluminous stishovite reveal that the dissolution of aluminum in stishovite can accommodate a significant population of both oxygen vacancies and hydrogen defects. The results show that the incorporation of aluminum in stishovite account for a 1.2(±0.1)% decrease in K0 per mole percent dissolved aluminum, independent of dissolution mechanism (hydrous or anhydrous). Elastic constants, calculated to be in agreement with experimentally-derived values, indicate that the rutile to CaCl2 transition is likely to be unaffected by the dissolution of small amounts of aluminum and/or hydrogen. As a result, the dissolution of aluminum into stishovite in a subducting basaltic layer will have no more than a 0.2% effect on the density of that layer as it enters the lower mantle.
Crosstalk noise in speckle-based volume holographic multiplexing

Recently, we proposed a new speckle-based hologram multiplexing recording technique. In this method, a multi-mode LiNbO3 single crystal fiber is employed to generate speckle patterns which are used as reference beams in hologram recording process. The speckle pattern generation can be precisely controlled by external E-field. Theoretically, this technique can generate thousands of decorrelated reference beams at given practical constraints. The system storage capacity has so far been estimated based on idealized settings. As it is well known that, besides the limitation set by the modulation mechanism capacity the storage density of a volume hologram memory system can be also restricted by many other factors. Among all factors, the crosstalk is a fundamental one that may ultimately put a tighter bound to system storage capacity. This paper is devoted to the theoretical analysis and numerical simulation of crosstalk in this proposed technique.
Diagnosis and epidemiology of community-acquired respiratory virus infections in the immunocompromised host

Infections due to community-acquired respiratory viruses are important causes of morbidity and mortality among immunocompromised patients. Respiratory syncytial virus, influenza viruses, and parainfluenza viruses are the most frequent causes of serious lower respiratory tract infections in this patient population. Early diagnosis, often possible with the use of rapid detection assays, is essential for optimal management and prevention of the spread of these serious infections to other vulnerable patients.
The distribution of the ornithine cycle enzymes in twelve gastropods

Abstract 1. 1. The hepatopancrease of twelve gastropods was checked for the ornithine cycle enzymes and urease. With the colorimetric assay only the prosobranchs, Marisa cornaurietis and Sinotia ingallisiana, were shown to biosynthesize citrulline. These data, along with reports of other workers using [14C]-bicarbonate incorporation into citrulline and urea, suggest that both prosobranchs and pulmonates probably are able to slowly synthesize citrulline. 2. 2. Although all of the snails possessed arginase and ornithine transcarbamylase, activity was consistently higher in pulmonates than in prosobranches. The overall reactions also was lower or absent in prosobranchs. Apparently arginine and urea biosynthesis occurs to some extent according to the ornithine cycle or a similar cycle in many snails. Urea biosynthesis seems of special importance during estivation of some pulmonates. 3. 3. Urease was found in Achatina fulica, Bulimulus dealbatus, Helix aspersa and Euglandina singleyana tissue, but its biological importance has not been established.
Mycorrhizae in Hawaiian angiosperms: a survey with implications for the origin of the native flora.

Endemic, indigenous, naturalized and cultivated angiosperms growing in a variety of habitats in Hawaii were examined for mycorrhizae. Of 147 species (representing 61 families) examined, 122 were mycorrhizal, and 98% of the latter formed vesicular-arbuscular mycorrhizae (VAM). Ericoid, orchid, and ectomycorrhizae also were found. Mycorrhizae were most frequent in endemic species (90.3%) and least in indigenous species (71.9%). The incidence of mycotrophy in Hawaiian endemic species was significantly greater than in mainland species. In addition, VAM often were found in species belonging to families that typically lack mycorrhizae (Aizoaceae, Brassicaceae, Caryophyllaceae, Cyperaceae, Hydrophyllaceae, Juncaceae, Pandanaceae, and Urticaceae). Naturalized weedy species were highly mycorrhizal. The high incidence ofmycorrhizae in endemic species suggests that VAM fungi and obligately mycotrophic plant species may have been present in the Hawaiian Islands from the earliest stages of the development of the angiosperm flora.
The Néel temperature of bcc 3He

Abstract The Neel temperature is calculated for bcc 3 He, imcluding the effect of triple exchange, using the 2-particle cluster approximation of Strieb, Callen and Horwitz. The inclusion of triple exchange raises the expected Neel temperature to between 2.5 and 2.9 mK.
Concurrency control for step-decomposed transactions

Abstract The throughput of a transaction processing system can be improved by decomposing transactions into steps and allowing the steps of concurrent transactions to be interleaved. In some cases all interleavings are assumed to be acceptable; in others certain interleavings are forbidden. In this paper we describe a new concurrency control that guarantees that only acceptable interleavings occur. We describe the implementation of the new control within the CA-Open Ingres tm database management system and experiments that were run to evaluate its effectiveness using the TPC-C tm Benchmark Transactions. The experiments demonstrate up to 80% improvement when lock contention is high, when long running transactions are a part of the transaction suite, and/or when sufficient system resources are present to support the additional concurrency that the new control allows. Finally, we describe a new correctness criterion that is weaker than serializability and yet guarantees that the specifications of all transactions are met. The criterion can be used to determine the acceptable interleavings for a particular application. The specification of these interleavings can serve as input to the new control.
Order director fluctuations contribute to the low-field magnetic relaxation of dilute solutes in a nematic solvent

Abstract High-resolution magnetic relaxation dispersion (HR-MRD) is used to measure the field dependence of the 19 F spin–lattice relaxation rates of C 6 F 6 dissolved in the nematic phase of p -methoxybenzilidene– p - n -butylaniline (MBBA). HR-MRD permits measurement of low concentration solute spectral densities, which can be interpreted in terms of the various contributions to the spin Hamiltonian and dynamical models of molecular motion. In this case, C 6 19 F 6 solute relaxation induced by magnetic dipole–dipole interactions reveal distinct components attributable to anisotropic rotational diffusion, and low-frequency order director fluctuations associated with the solvent.
Modeling within-subject dependencies in ordinal paired comparison data

This paper presents two probabilistic models based on the logistic and the normal distribution for the analysis of dependencies in individual paired comparison judgments. It is argued that a core assumption of latent class choice models, independence of individual decisions, may not be well-suited for the analysis of paired comparison data. Instead, the analysis and interpretation of paired comparison data may be much simplified by allowing for within-person dependencies that result from repeated evaluations of the same options in different pairs. Moreover, by relating dependencies among the individual-level responses to (in)consistencies in the judgmental process, we show that the proposed graded paired comparison models reduce to ranking models under certain conditions. Three applications are presented to illustrate the approach.
Source of oxygen in cytochrome P-450 catalyzed carbinolamine formation.

Abstract N-Methylcarbazole was incubated in H2O18 and under an 18O atmosphere. N-Hydroxymethylcarbazole, 1-OH- and 3-OH-N-methylcarbazole were isolated by HPLC and analyzed for 18O content In incubations containing 18O, all three metabolites showed >95% 18O incorporation. In incubations containing H2O18, the N-hydroxymethyl metabolite showed 16O incorporation equal to control incubations in 100% H2O. These data demonstrate that the sole source of oxygen in cytochrome P-450 catalyzed, NADPH supported N-hydroxymethylcarbazole formation is atmospheric oxygen.
Loss of fertilization potential of desiccated rhesus macaque spermatozoa following prolonged storage.

Abstract Desiccation provides a novel spermatozoal preservation technique because it eliminates the need to store spermatozoa in liquid nitrogen, resulting in decreased opportunities for cross-contamination of samples and lower costs of spermatozoal banking, storage, and shipping. The objective of this study was to desiccate rhesus macaque spermatozoa and to evaluate the fertility following storage. Semen from four male rhesus macaques ( Macaca mulatta ) were collected using electroejaculation, washed through a Percoll gradient, and resuspended to 100 × 10 6 spermatozoa/mL in a simple vacuum drying buffer containing the disaccharide trehalose (10 mM HEPES, 5 mM KCl, 65 mMNaCl, 150 mMtrehalose, 5.7% bovine serum albumin, BSA). Cells were desiccated in 50 μl drops under vacuum (22 inHg) at ambient temperature until the water content was less than 1 g H 2 O/g dry weight. Initial motility was high (90–70%) and was reduced by desiccation (0%). Membrane integrity was investigated using the two fluorochromes, SYBR 14 and propidium iodide (PI, Molecular Probes, Inc.), with flow cytometry. After desiccation, 100% of the spermatozoa were stained red with PI indicating plasma membrane compromise. Samples were stored in air-tight polyvinyl plastic bags purged with N 2 gas for 10 s and vacuum sealed. The samples were protected from light and either stored at room temperature (treatment 1) or at −80 °C (treatment 2). Samples were rehydrated 7–10 days post desiccation in 150 μl BWW containing 0.5% BSA and used for intracytoplasmic spermatozoa injection (ICSI) to compare fertilization and embryo development to freshly collected samples. For control embryos, one freshly ejaculated motile sperm with normal morphology was immobilized by scoring a small incision in the plasma membrane over the sperm tail before injecting into an oocyte. For the dried sperm treatments, one sperm with normal morphology was selected and scored before injecting into an oocyte. After injection, the embryos were individually cultured in CMRL medium with 10% fetal bovine serum (FBS) media on pre-plated buffalo rat liver (BRL) cells at 37 °C and 5% CO 2 . Fertilization was assessed at 14, 16, 22, and 24 h. Embryo development was evaluated daily from day 3 to day 11. The fertilization rate was 68%, 73%, and 45% for the control, treatment 1, and treatment 2 groups, respectively. The blastocyst rate was 40%, 5%, and 0% for control, treatments 1, and 2, respectively. Treatment group 1 had comparable fertilization rates with control group (73% vs. 68%) and was not significantly different ( P
Lipid Metabolism in Pregnancy. IV. C Apoprotein Changes in Very Low and Intermediate Density Lipoproteins

In vitro studies indicate that relative amounts of apolipoproteins CII and CIII in plasma may alter lipoprotein lipase mediated triglyceride removal from very low density lipoprotein. Therefore, we have determined relative amounts of these peptides in pregnant women in late gestation (mean 36 weeks) and 6 and 20 weeks postpartum. Very low density (d less than 1.006) and intermediate density (d 1.006-1.019) lipoproteins have been examined because they are affected similarly in pregnancy. Triglyceride and cholesterol in these two fractions increased 3 1/2 to 4 1/2-fold in pregnancy in keeping with previous reports. On a relative basis, apo CII was decreased and apo CIII1 and CIII2 increased in both VLDL and IDL at 36 weeks gestation. At 6 and 20 weeks postpartum relative amounts of C peptides returned to identical levels and were unaffected by lactation. It remains to be seen if in vivo triglyceride removal in pregnancy is altered by the reduction in apo CII relative to apo CIII.
Effects of bias stress on ZnO nanowire field-effect transistors fabricated with organic gate nanodielectrics

The effects of bias stress (gate stress or drain stress) on nanowire field-effect transistor (NW-FET) stability were investigated as a function of stress bias and stress time. The n-channel NW-FETs used a nanoscopic self-assembled organic gate insulator, and each device contained a single ZnO nanowire. Before stress, the off current is limited by a leakage current in the 1nA range, which increases as the gate to source bias becomes increasingly negative. The devices also exhibited significant changes in threshold voltage (Vth) and off current over 500 repeated measurement sweeps. The leakage current was significantly reduced after gate stress, but not after drain stress. Vth variations observed upon successive bias sweeps for devices following gate stress or drain stress were smaller than the Vth variation of unstressed devices. These observations suggest that gate stress and drain stress modify the ZnO nanowire-gate insulator interface, which can reduce electron trapping at the surface and therefore redu...
An electrochemical double layer capacitor based on nanocrystalline lead ruthenate pyrochlore

Lead ruthenate pyrochlore Pb2Ru2O7−x was synthesized as a new electrode material for aqueous-electrolyte electrochemical capacitors. The material was characterized using X-ray diffraction, thermogravimetric analysis, BET area analysis, and cyclic voltammetry. Redox processes significantly improve the capacitance of the materials compared to the conventional double layer capacitors. For materials heated at low temperatures, the redox processes merge smoothly resulting in an excellent capacitive behavior. The capacitors built with the lead-ruthenate electrodes show an excellent electrochemical performance under constant-power discharge.
Shape and motion of nonrigid bodies

Abstract In computer vision and image understanding research, rigidity of bodies and their motions has long been a key assumption in obtaining 3-dimensional shape and motion information from 2-dimensional images. In this paper, the rigidity assumption is relaxed in several fundamental problems. Nonrigid, elastic bodies under perspective projection are considered. Deformations of such bodies are diffeomorphisms of R3 in the case of static elasticity. For dynamic elasticity, generalized motions (including deformations) are represented by 1-parameter families of diffeomorphisms of R3. The primary goal is to determine a generalized motion of a known nonrigid, elastic body given images of the body before and after the generalized motion. Although there is no uniqueness result in general, a closed form solution is obtained for an isometric generalized motion given the corresponding image transformation. Further, an approach to the shape-from-shading method is presented which yields complete local surface information.
Applications and Outcomes of Orbital and Transorbital Endoscopic Surgery

Objective. To prospectively evaluate the safety, effectiveness, and utility of orbital and transorbital endoscopic surgery.Study Design. Case series with planned data collection.Setting. Level 1 trauma center and tertiary academic hospital.Subjects and Methods. Consecutive sample of 107 patients undergoing orbital or transorbital endoscopic operations.Main Outcome Measures. Ability to achieve intraoperative goals using endoscopic approach; occurrence of predetermined intraoperative or postoperative complications.Results. One hundred seven patients (aged 6-83 years) underwent orbital or transorbital endoscopic surgery for 6 different indications. Seven incisions were used. Endoscopic orbitotomies were made through all 4 orbital walls to access surrounding structures. Intraoperative goals were achieved endoscopically in 106 patients. Mean follow-up was 3 months (mean ± SD, 3.0 ± 3.5). No complication was directly related to surgical approach or use of endoscopy. Seventeen complications were detected in 2 ca...
Breaking and entering into the CNS: clues from solid tumor and nonmalignant models with relevance to hematopoietic malignancies.

Various malignancies invade the CNS sanctuary site, accounting for the vast majority of CNS neoplastic foci and contributing to significant morbidity as well as mortality. The blood–brain barrier (BBB) exhibits considerable impermeability to chemotherapeutic agents, severely limiting therapeutic options available for patients developing metastatic CNS involvement, accounting for poor outcomes. The mechanisms by which malignant cells breach the highly exclusive BBB and subsequently survive in this unique anatomical site remain poorly understood, with most of the current knowledge stemming from nonmalignant and solid malignancy models. While solid and hematologic malignancies may face different challenges once within the CNS (e.g., solid tumor parenchymal metastasis compared to masses/nodules/leptomeningeal disease in hematologic malignancies), commonality exists in the process of migrating across the BBB from the circulation. Specifically considering this last point, this review aims to survey the current mechanistic knowledge regarding malignant migration across the BBB, necessarily emphasizing the better studied solid tumor and nonmalignant models with the intention of highlighting both the current knowledge gap and additional work required to effectively consider how hematopoietic malignancies breach the CNS.
Adeno-associated virus DNA replication: Nonunit-length molecules

Abstract Nonunit-length adeno-associated virus (AAV) DNA molecules which incorporate radiolabel during a short pulse were isolated from infected cells and characterized with regard to structure and to their potential role as replicative intermediates. Two classes of molecules were observed. (1) Dimer length duplex molecules containing the entire AAV genome were shown to be precursors to mature unit length AAV DNA. About one-third of the single strands from these molecules were dimers, the rest being of unit length. Some of these dimeric duplex molecules contain a hairpinned terminal structure formed by folding over of the terminal repetition from the right end of the AAV genome. (2) Smaller than unit-length molecules contain only the terminal 10–25% of the AAV genome and are not processed to unit-length genomes. They have one natural AAV terminus and a hairpinned internal terminus. Both classes of AAV molecules can be generated from a replication model utilizing the 3′-OH end of a hairpinned palindromic AAV terminal sequence as a primer for daughter-strand synthesis. The short, defective molecules result from a template strand switch to either the complementary strand of the parental duplex or to the newly synthesized complementary strand.
Inhibition of cell division by blue light.

Abstract Microsporocytes of Lilium and Trillium can revert into a mitotic cycle when separated from the anther before the beginning of meiosis and cultured in vitro. Repeated short daily irradiations with visible blue light (10 6 ergs cm −2 sec −1 ) inhibit the onset of mitosis; the cells remain in interphase instead. The inhibition of cell division is reversed after the end of the light treatment. Meiosis is not affected by light. Part of the premeiotic G2 phase is light sensitive. No arrest of DNA-, RNA- or protein synthesis is involved in the photoinhibition of onset of mitosis. Irradiation with blue light decreases the α- absorption band of cytochrome a 3 but not of cytochrome a . This effect on cytochrome oxidase, however, is observed in all stages of meitotic prophase as well as in G2 cells.
The selenium content of U.S.G.S. standard rocks

Abstract Selenium was determined in duplicate portions from three bottles of six U.S.G.S. standard rocks by a spect rofluorimetric procedure. The following averages, as p.p.m. Se, were obtained: PCC-1, 0.031; GSP-1, 0.088; BCR-1, 0.12; SCo-1, 0.91; MAG-1, 1.3; and SGR-1, 3.7. One-way analysis of variance of the several sets of data showed no significant differences in the selenium content among bottles of any specific rock; these samples may be accepted as homogeneous for their selenium contents by this analytical method.
Cryptic genetic variation: evolution's hidden substrate

Cryptic genetic variation (CGV) is invisible under normal conditions, but it can fuel evolution when circumstances change. In theory, CGV can represent a massive cache of adaptive potential or a pool of deleterious alleles that are in need of constant suppression. CGV emerges from both neutral and selective processes, and it may inform about how human populations respond to change. CGV facilitates adaptation in experimental settings, but does it have an important role in the real world? Here, we review the empirical support for widespread CGV in natural populations, including its potential role in emerging human diseases and the growing evidence of its contribution to evolution.
Applications of functional surfactants

Recent studies have reported the introduction of a range of new chemical and biochemical functionalities into the structures of amphiphilic molecules. Assemblies spontaneously formed by these amphiphiles are in many cases highly complex and possess properties not found in systems formed from amphiphiles with simpler structures. In particular, the incorporation of peptides and oligopeptides into the hydrophilic domains of amphiphiles has led to new classes of surfactants that self-assemble into structures that mimic a variety of the functions of natural materials (including organic scaffolds of bone; inhibitors of proteins involved in viral infection; chiral polymeric amphiphiles; materials that promote adhesion of cells to surfaces). Amphiphiles functionalized with a range of carbohydrates have also been reported. These amphiphiles assemble into aggregate morphologies that depend strongly on the stereochemistry of the carbohydrate. These assemblies offer the basis of promising approaches for the design of polyvalent (potent) carbohydrate-based drugs. Finally, the introduction of redox-active and polymerizable functional groups into the structures of amphiphiles has provided the basis of a class of novel tunable solvents with potential applications in separations technologies as well as new materials that exhibit controlled release and catalytic properties.
Nursing doctoral program evaluation: Alumni outcomes.

Abstract Meaningful examination of program outcomes is one of the most challenging tasks facing faculty and administrators involved in the design and delivery of educational programs. This article reports the outcomes for one doctoral program in nursing and elucidates salient conceptual and methodologic issues in educational outcomes research for this discipline. Career development, scholarly productivity, and professional leadership were the foci of this outcomes study. Three instruments were used; data were provided by alumni, graduate faculty, and alumni supervisors. Data analysis techniques included content analysis and descriptive and correlational statistics. Results showed that graduates embarked on diverse career paths with the majority employed in academic institutions. Most graduates reported active involvement in research, publications, presentations, and professional leadership. Employment pattern differences were noted between academic year and summer-only program graduates with associated divergence in career emphasis, research productivity, and job satisfaction. A positive correlation of time since degree conferral with scholarly productivity and professional leadership was noted. Recommendations for future research include refining outcomes, linking process to outcome, using longitudinal designs, and attending to unique nursing student and doctoral program characteristics. J Prof Nurs 17:87-95, 2001. Copyright © 2001 by W.B. Saunders Company
Psychophysics, visibility and perceived atmospheric transparency

Abstract Layered or regional haze often appears to be a separate, semi-transparent layer overlying a background of mountains and sky. When perceived in this way, the apparent brightness and color of the haze layer and features seen through the haze can be profoundly influenced by the perception of transparency and depth in the scene. Changes in achromatic brightness related to perceived transparency can be quantitatively estimated by the theory of color scission. This theory predicts, for example, that mountains seen through a veil of white haze appear darker than they would if transparency and depth perception were not involved. Also, using the theory, an index of perceptual transparency of the haze can be defined. The results of an experiment to test predictions of the theory are reported. Observers estimated the apparent brightness of distant mountains using a 32-step Munsell brightness scale while a teleradiometer recorded physical light intensities from the mountain and nearby sky. Calculations based on the experimental observations support the theory of color scission as an explanation of perceived transparency. Transparency effects typically alter subjectively determined brightness of mountains seen through haze by 10–40 % with changes as large as 60% observed. As such, these perceptual effects are as large or larger than those expected from changes in pollution levels. Also, the calculated index of perceptual transparency is seen to be related to physical contrast, although further work is needed to fully explore its connections with this and other physical parameters.
The Effect of High Order Non-Linearities on Sub-Harmonic Excitation With Parallel Plate Capacitive Actuators

Electrostatic actuation of motion is commonly used in resonant MEMS. Drive signal feed-through is undesirable as it masks the detection signal. This paper reports analysis and demonstration of a resonant motion excitation scheme, which uses a combination of a DC bias with a sinusoidal AC voltage, frequency of which is twice of the mechanical resonant frequency. This configuration is experimentally demonstrated to excite a gyroscope with a parallel plate drive capacitor into high amplitude periodic vibrations. The feed-through has a frequency higher than the main motional harmonic and thus can be eliminated by simple low pass filtering. Full nonlinear dynamics along with several higher-order approximations are considered. Analysis of the effect of the approximation order on the frequency response accuracy shows that the complete nonlinear equation should be used for modeling of high amplitude actuation. Two distinct types of frequency responses are examined as functions of driving AC and DC voltages and damping.Copyright © 2007 by ASME
HR in collaborative innovation with customers: role, alignment and challenges

Companies are engaging in collaborative innovation with their customers (CIC), but there has been no comprehensive discussion of the role of human resources (HR) in such initiatives or the challenges involved. We begin with a brief overview of CIC and the challenges for HR and then draw on different streams of research to develop a conceptual framework for the alignment of HR with CIC strategies. Theoretical foundations for the components of the framework are integrated with the discussions of its various components. We begin with a review of staffing and development practices focused on collaboration and relationship skills, as well as creativity, and collaborative- and commitment-oriented HR systems. We then discuss how HR deployment, performance management, control practices and contextual factors potentially affect the relationship between antecedent HR practices and the collaborative and innovative behaviors needed for CIC. Several challenges in aligning HR practices with CIC are explored, such as th...
An insulator element 3′ to the CFTR gene binds CTCF and reveals an active chromatin hub in primary cells

Regulation of expression of the CFTR gene is poorly understood. Elements within the basal promoter of the gene do not fully explain CFTR expression patterns, suggesting that cis-regulatory elements are located elsewhere, either within the locus or in adjacent chromatin. We previously mapped DNase I hypersensitive sites (DHS) in 400 kb spanning the CFTR locus including a cluster of sites close to the 3'-end of the gene. Here we focus on a DHS at +6.8 kb from the CFTR translation end-point to evaluate its potential role in regulating expression of the gene. This DHS, which encompasses a consensus CTCF-binding site, was evident in primary human epididymis cells that express abundant CFTR mRNA. We show by DNase I footprinting and electophoretic mobility shift assays that the cis-regulatory element within this DHS binds CTCF in vitro. We further demonstrate that the element functions as an enhancer blocker in a well-established in vivo assay, and by using chromatin immunoprecipitation that it recruits CTCF in vivo. Moreover, we reveal that in primary epididymis cells, the +6.8 kb DHS interacts closely with the CFTR promoter, suggesting that the CFTR locus exists in a looped conformation, characteristic of an active chromatin hub.
Geochemical modeling of iron, sulfur, oxygen and carbon in a coastal plain aquifer

Abstract Fe(III) reduction in the Magothy aquifer of Long Island, NY, results in high dissolved-iron concentrations that degrade water quality. Geochemical modeling was used to constrain iron-related geochemical processes and redox zonation along a flow path. The observed increase in dissolved inorganic carbon is consistent with the oxidation of sedimentary organic matter coupled to the reduction of O2 and SO42− in the aerobic zone, and to the reduction of SO42− in the anaerobic zone; estimated rates of CO2 production through reduction of Fe(III) were relatively minor by comparison. The rates of CO2 production calculated from dissolved inorganic carbon mass transfer (2.55×10−4 to 48.6×10 −4 mmol l −1 yr −1 ) generally were comparable to the calculated rates of CO2 production by the combined reduction of O2, Fe(III) and SO42− (1.31×10−4 to 15×10 −4 mmol l −1 yr −1 ). The overall increase in SO42− concentrations along the flow path, together with the results of mass-balance calculations, and variations in δ34S values along the flow path indicate that SO42− loss through microbial reduction is exceeded by SO42− gain through diffusion from sediments and through the oxidation of FeS2. Geochemical and microbial data on cores indicate that Fe(III) oxyhydroxide coatings on sediment grains in local, organic carbon- and SO42−-rich zones have been depleted by microbial reduction and resulted in localized SO42−-reducing zones in which the formation of iron disulfides decreases dissolved iron concentrations. These localized zones of SO42− reduction, which are important for assessing zones of low dissolved iron for water-supply development, could be overlooked by aquifer studies that rely only on groundwater data from well-water samples for geochemical modeling.
Characterization and localization of carcinoembryonic antigen in a squamous cell carcinoma of the cervix

Abstract The carcinoembryonic antigen (CEA) of a patient with squamous cell carcinoma of the cervix whose plasma CEA titer was 28 μg/ml and tumor CEA concentration was 900 μg/g was subjected to immunological and physicochemical analyses. By means of immunodiffusion and immunoelectrophoresis, cervical cancer CEA was found to be immunologically identical to colonic cancer CEA. However, cervical cancer CEA appeared in gel filtration to be 370,000 in molecular size, thus being appreciably larger than the 200,000 size CEA usually found in colonic carcinomas. The CEA in this squamous cell carcinoma of the cervix was localized by an immunoperoxidase reaction performed on paraffin sections of the tumor and was found to be almost exclusively present on the surface of the tumor cells. It appears that this immunocytochemical procedure for CEA detection and localization can be employed in the routine histopathological evaluation of such neoplastic tissues.
Spatial Distribution of the Pathways of Cholesterol Homeostasis in Human Retina

Background The retina is a light-sensitive tissue lining the inner surface of the eye and one of the few human organs whose cholesterol maintenance is still poorly understood. Challenges in studies of the retina include its complex multicellular and multilayered structure; unique cell types and functions; and specific physico-chemical environment.
Tension pneumothorax during extracorporeal membrane oxygenation

Life-threatening tension pneumothorax in neonates on extracorporeal membrane oxygenation (ECMO) has been associated with an increase in arterial oxygen tension and a decrease in peripheral perfusion, followed by a decrease in ECMO flow with progressive hemodynamic deterioration. To investigate this triad, chest tubes were placed bilaterally in 9 dogs to allow injection of air to produce tension pneumothorax. Six dogs were subsequently placed on standard venoarterial ECMO before the reinduction of tension pneumothorax. Measured values included arterial pulse pressure, inferior vena cava pressure, systemic arterial blood gases, peripheral arterial oxygen saturation, mixed venous oxygen saturation, and left heart cardiac output. Oxygen delivery was calculated from directly measured values. Each of the 6 dogs on ECMO demonstrated the triad of increased arterial oxygen tension (92 +/- 7 to 325 +/- 20 mm Hg; p less than 0.05), decreased peripheral perfusion (as evidenced by a decrease in pulse pressure from 55 +/- 4 to 31 +/- 5 mm Hg; p less than 0.05), and decreased mixed venous oxygen saturation (71% +/- 3% to 22% +/- 2% saturation; p less than 0.05) followed by a lower ECMO flow with progressive hemodynamic deterioration (oxygen delivery decreased from 285 +/- 11 to 111 +/- 12 mL/min; p less than 0.05). Aspiration of the intrathoracic air allowed return to baseline ECMO flow and hemodynamic stability in all dogs. The triad of increased arterial oxygen tension and decreased peripheral perfusion (as evidenced by a lower arterial pulse pressure and lower mixed venous oxygen saturation) followed by decreased ECMO flow with progressive hemodynamic deterioration consistently appears when tension pneumothorax occurs on ECMO.
Micrometastasis in lymph node

Determining whether cancer has spread to the lymph nodes is important in predicting survival from breast cancer and determining what treatment a patient requires. The traditional method of detecting such metastases, complete axillary node dissection, can result in lymphedema and other quality-of-life damaging side effects. The new technique of sentinel lymph node biopsy (SLNB) offers a way to test for lymph node metastases without causing the side effects of traditional axillary node dissection. Intraoperative analysis of SLNB is becoming an effective tool in assessment of the presence or absence of metastatic tumor, and therefore influences the treatment offered to the patient. Because of this central diagnostic use, as it is a new procedure, further studies need to be conducted to fully assess its role in breast cancer treatment.
Induction of antigen-specific regulatory T cells following overexpression of a Notch ligand by human B lymphocytes

In mice, activation of the Notch pathway in T cells by antigen-presenting cells overexpressing Notch ligands favors differentiation of regulatory T lymphocytes responsible for antigen-specific tolerance. To determine whether this mechanism operates in human T cells, we used Epstein-Barr virus-positive lymphoblastoid cell lines (EBV-LCL) as our (viral) antigen-presenting cells and overexpressed the Notch ligand Jagged-1 (EBV-LCL J1) by adenoviral transduction. The EBV-LCL J1s were cocultured with autologous T cells, and the proliferative and cytotoxic responses to EBV antigens were measured. Transduction had no effect on EBV-LCL expression of major histocompatibility complex (MHC) antigens or of costimulatory molecules CD80, CD86, and CD40. However, we observed a 35% inhibition of proliferation and a >65% reduction in cytotoxic-T-cell activity, and interleukin 10 production was increased ninefold. These EBV-LCL J1-stimulated T lymphocytes act as antigen-specific regulatory cells, since their addition to fresh autologous T cells cultured with autologous nontransduced EBV-LCL cells significantly inhibited both proliferation and cytotoxic effector function. Within the inhibitory population, CD4(+)CD25(+) and CD8(+)CD25(-) T cells had the greatest activity. This inhibition appears to be antigen-specific, since responses to Candida and cytomegalovirus antigens were unaffected. Hence, transgenic expression of Jagged-1 by antigen-presenting cells can induce antigen-specific regulatory T cells in humans and modify immune responses to viral antigens.