cssi/SciSciGPT-SciSciNet huggingface dataset:
Nuclear and cytoplasmic DNA synthesis in cotton embryos: a correlated light and electron microscope autoradiographic study.

To investigate the possibility, implied by an earlier report, that large amounts of degradable DNA are probably present in the cytoplasm of young cotton embryos, an investigation was undertaken to establish the distribution, amount and metabolic stability of DNA in cotton embryos. Several sensitive cytochemical tests failed to detect any but small amounts of extranuclear DNA. Quantitative determination of the nucleic acid content of embryos during embryogenesis showed that the amounts of DNA and RNA remained fairly constant during embryogenesis, with a ratio of RNA to DNA of about 3.5 to 1. Quantitative autoradiography at both the light and electron microscope levels of sections from embryos pulse-labeled with 3H-thymidine showed that the grain density over the nucleus and cytoplasm did not change during a seven-hour period after labeling, nor did the distribution of label in the cytoplasm. Virtually all incorporation was eliminated by the inclusion of iododeoxy-uridine in the medium. Almost all of the nuclear label and at least 90% of the cytoplasmic label after 3H-thymidine incorporation was eliminated by deoxyribonuclease. It was concluded that there are no unusual features related to DNA distribution or metabolism in cotton embryo; i.e., that only small amounts of DNA are present in the cytoplasm and that all of the DNA is metabolically stable.
Unsteady Aerodynamic Interaction in a Closely Coupled Turbine Consistent With Contrarotation

The focus of the study presented here was to investigate the interaction between the blade and downstream vane of a stage-and-one-half transonic turbine via computation fluid dynamic (CFD) analysis and experimental data. A Reynolds-averaged Navier–Stokes (RANS) flow solver with the two-equation Wilcox 1998 k–ω turbulence model was used as the numerical analysis tool for comparison with all of the experiments conducted. The rigor and fidelity of both the experimental tests and numerical analysis methods were built through two- and three-dimensional steady-state comparisons, leading to three-dimensional time-accurate comparisons. This was accomplished by first testing the midspan and quarter-tip two-dimensional geometries of the blade in a linear transonic cascade. The effects of varying the incidence angle and pressure ratio on the pressure distribution were captured both numerically and experimentally. This was used during the stage-and-one-half post-test analysis to confirm that the target corrected speed and pressure ratio were achieved. Then, in a full annulus facility, the first vane itself was tested in order to characterize the flowfield exiting the vane that would be provided to the blade row during the rotating experiments. Finally, the full stage-and-one-half transonic turbine was tested in the full annulus cascade with a data resolution not seen in any studies to date. A rigorous convergence study was conducted in order to sufficiently model the flow physics of the transonic turbine. The surface pressure traces and the discrete Fourier transforms (DFT) thereof were compared to the numerical analysis. Shock trajectories were tracked through the use of two-point space–time correlation coefficients. Very good agreement was seen when comparing the numerical analysis to the experimental data. The unsteady interaction between the blade and downstream vane was well captured in the numerical analysis.
Studies on the Pathway of Incorporation of 2-Aminopurine into the Deoxyribonucleic Acid of Escherichia coli

Abstract A pathway for the incorporation of 2-aminopurine into deoxyribonucleic acid (DNA) was studied in cell-free extracts of Escherichia coli. It was demonstrated that the free base can be converted to the deoxynucleoside, and that the deoxynucleotide can be phosphorylated to the di- and triphosphates and then incorporated into the DNA. From a consideration of the individual reactions in crude extracts, it is likely that the rate-limiting step in this pathway is the formation of the deoxynucleotide. Of especial interest is the observation that 2-aminopurine may be viewed as an analogue of either guanine or adenine, depending on which enzymatic step is being considered. On the one hand, it resembles guanine in that it is specifically converted from the mono- to the diphosphate by guanylate kinase and not by adenylate kinase. On the other hand, it replaces adenine rather than guanine in the DNA synthesized with purified DNA polymerases. E. coli DNA polymerase utilizes aminopurine deoxynucleoside triphosphate as a substrate for DNA synthesis much better than does purified phage T5-induced DNA polymerase and is also much less inhibited by this analogue than the T5 enzyme. These experiments in vitro correlate with known differential effects of 2-aminopurine on E. coli and phage in vivo.
Chapter 6 Prenatal development of axon outgrowth and connectivity

Publisher Summary This chapter focuses mainly on the aspects of normal prenatal and early postnatal development of the ferret retina, lateral geniculate nucleus (LGN), visual cortex, and their connections, although aspects of the ontogeny of other systems and species are mentioned where relevant. Thus, in regions such as the optic chiasm or LGN, different waves of retinal axons may encounter different environments because cues at specific choice points and the relative maturity of target cells may differ. Permanent axons may be guided to their individually specific targets by radial glial cells. It is not only in a position to guide axons, but also to align axons with target cells within a topographic column. However, the exact roles of radial glia with respect to retinal, thalamocortical, and corticothalamic axon pathfinding remain to be defined. Once rough topographic connections have been established within the ferret visual system, fine tuning of connections appears to depend upon neural activity.
Institutional collective action in an ecology of games

The main goal of this volume is to explain how governance authorities in a particular policy arena overcome fragmentation and solve vertical and horizontal collective action problems. Our chapter addresses this goal in two ways: first, we apply Norton Long's (1958) analysis of the ecology of games played in territorially defined metropolitan areas to regional governance, and second, we analyze the relationships between collaboration networks, trust, and political influence in the context of regional land-use and transportation policy. The central argument of the ecology of games framework is that local political outcomes emerge from actors pursuing their self-interest in multiple, interdependent, and rule-structured games. The resulting decisions lead to the type of fragmentation and decision externalities discussed throughout this volume. Collaborative partnerships and networks are considered potential self-organizing mechanisms for overcoming these dilemmas, and our empirical study explicitly examines the resulting patterns of cooperation, trust, and political influence. Our use of the ecology of games metaphor is partly a reaction to the burgeoning social science literature that examines the dynamics and effectiveness of collaborative processes as new institutions for political decision making. This literature itself has emerged in response to (and perhaps also partly caused) the widespread appearance of collaborative policy and its aliases in nearly every policy subsystem, especially environmental policy (O'Leary, Gerard, and Bingham 2006). These collaborative institutions are designed to alleviate many symptoms of institutional collective action (ICA) problems discussed in this book.
A List of Late-Type Stars in the Galactic Antirotation Direction

Low-resolution objective-prism spectra (1360 A mm–1 at Hγ) of 184 late-type stars in the Galactic antirotation direction have been obtained with the Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory. The stars have been classified into three groups: F6-G2, G3-K0, and K1-M8. Subsequent observations on the BV and DDO systems have been obtained. The correlation between the thin-prism classes and the DDO classes is as expected, with no significant systematic differences of note. A comparison of Guide Star Catalog magnitudes, corrected to V, is also made, with favorable results. The stars in this list are expected to be useful for studying the structure and star formation history of the Milky Way.
Incubation-derived calcium carbonate equivalence of papermill boiler ashes derived from sludge and wood sources

The burning of a papermill sludge and wood mixture and landspreading the resulting ash is a potential means of disposal of papermill sludge without the use of valuable landfill space. This study evaluated the effectiveness of ashes derived from a mixture of papermill sludge and wood sources to act as an alternative liming agent. The calcium carbonate equivalence of the material was determined using a 91-day laboratory incubation test with three mineral soils and one organic horizon soil. Application rates of soil-incorporated sludge-ash ranged from 2.30 to 32.2 g per kg soil. Soil pH increased linearly with increasing sludge-ash application rate. The calcium carbonate equivalence of the material varied temporally and the average value ranged from 19% to 28%. The fraction of total P, K and Mg added with the sludge-ash and extracted from the ash-amended soils using an NH4OAc based soil test method were 2.6, 3.8 and 17.6%, respectively. The low soil test extractability of ash-derived plant nutrients suggests that this material would provide only a modest increase in plant available nutrient levels in landspread fields.
Miocene to recent eolian dust record from the Southwest Pacific Ocean at 40° S latitude

Abstract A 14-meter long pelagic clay core recovered at Marlin Rise (40°00.531′S, 154°2.601′W; 4775 m water depth) in the Southwest Pacific Basin contains a record of eolian dust deposited since the early Miocene. Downcore analysis of detrital minerals reveals a dominantly eolian signature with relatively constant proportions of quartz, feldspar and illite and trace amounts of chlorite, kaolinite and smectite, consistent with a continental (loess-like) source region. Fish tooth Sr isotope stratigraphy reveals the base of the core to be 17.5 Ma, with low sedimentation rates (
Enabling MPI interoperability through flexible communication endpoints

The current MPI model defines a one-to-one relationship between MPI processes and MPI ranks. This model captures many use cases effectively, such as one MPI process per core and one MPI process per node. However, this semantic has limited interoperability between MPI and other programming models that use threads within a node. In this paper, we describe an extension to MPI that introduces communication endpoints as a means to relax the one-to-one relationship between processes and threads. Endpoints enable a greater degree interoperability between MPI and other programming models, and we illustrate their potential for additional performance and computation management benefits through the decoupling of ranks from processes.
Outcome Analysis of Cochlear Implant Reimplantation in Children

Objectives: We review our experience gained in performing cochlear reimplantation in 25 children who have had multichannel cochlear implant device failure at the Cochlear Implant Center of the Manhattan Eye, Ear and Throat Hospital and Lenox Hill Hospital (New York, NY), to assess the feasibility of cochlear reimplantation in children and the effect of reinsertion on audiological performance. Study Design: We retrospectively analyzed the outcome of 27 consecutive multichannel cochlear implant reinsertions performed in 25 children at the Manhattan Eye, Ear and Throat Hospital and Lenox Hill Hospital. These reimplantations were performed between 1990 and 1999, with a minimum follow-up of 6 months for both surgical and audiological performance. Methods: Charts were reviewed for patient factors, findings at the time of initial operation and repeat operation, and results of audiological testing both before and after reimplantation. Results: Surgical complications of reimplantation included two intraoperative cerebral spinal fluid leaks and two late postoperative flap breakdowns with implant extrusions. For the most part, depth of electrode insertion was unchanged. Open-set speech recognition scores and speech perception abilities remained stable or improved compared with results before reimplantation. Conclusion: Our results confirm that cochlear implant reimplantation is technically feasible and allows for continued auditory development for the child who has a cochlear implant device failure.
Effects of beam polarization on Λ and K 0 inclusive production in pp interactions at 12 GeV/ c

Inclusive production of ..lambda.. and K/sup 0/ in pp interactions at 12 GeV/c has been studied in an exposure of the Argonne National Laboratory 12-foot bubble chamber to a 50% transversely polarized proton beam. Beam-polarization-induced asymmetries are observed for both K/sup 0/ and ..lambda.. production in the forward direction.
Interleukin-2 production during intravesical bacille Calmette-Guerin therapy for bladder cancer

Abstract Interleukin-2 (IL-2) was detected in urine but not serum of patients receiving intravesical bacille Calmette-Guerin (BCG) therapy for bladder cancer. IL-2 activity was neutralized by anti-IL-2 antibody. No IL-2 was detected in urine before BCG therapy or from control donors. BCG-induced urine IL-2 peaked 4–8 hr after treatment but was rarely observed after 24 hr. The presence of BCG-induced lymphokines may be associated with antitumor activity.
Diffusion of telemedicine: a knowledge barrier perspective

Telemedicine, broadly defined as the use of information technology (IT) to deliver medical services over distances, is one proposed solution to problems of accessibility, quality, and costs of medical care. Although telemedicine applications have proliferated in recent years, their diffusion has remained low in terms of the volume of consultations. In this study, we extend Attewell's theory of knowledge barriers to explain why diffusion of telemedicine remains low. A longitudinal, embedded multiple case study of telemedicine programs in three medical centers in Boston, Massachusetts, reveals that, in addition to technical knowledge barriers, as suggested by Attewell, there are economic, organizational, and behavioral knowledge barriers that inhibit the diffusion of telemedicine. The lowering of these barriers entails intensive learning efforts by champions of applications within adopter organizations. They need to develop technically feasible, medically valid, reimbursable, and institutionally supported a...
Design of an intelligible mobile context-aware application

Context-aware applications are increasingly complex and autonomous, and research has indicated that explanations can help users better understand and ultimately trust their autonomous behavior. However, it is still unclear how to effectively present and provide these explanations. This work builds on previous work to make context-aware applications intelligible by supporting a suite of explanations using eight question types (e.g., Why, Why Not, What If). We present a formative study on design and usability issues for making an intelligible real-world, mobile context-aware application, focusing on the use of intelligibility for the mobile contexts of availability, place, motion, and sound activity. We discuss design strategies that we considered, findings of explanation use, and design recommendations to make intelligibility more usable.
Urinary incontinence in female Parkinson disease patients. Pitfalls of diagnosis.

Abstract There are many causes of urinary incontinence in the female, with stress incontinence reported as the most common. However, a high incidence of detrusor instability has been described in incontinent patients with Parkinson disease. To assess this further, urodynamic studies were performed on 17 female patients with Parkinson disease and complaints of urinary dysfunction. Detrusor instability was demonstrated in the majority of the patients (70.6 %). Of the 8 patients with specific symptoms of stress incontinence, 2 were found to have a stable bladder, 3 had a hyporeflexic bladder, and 3 had detrusor instability. Surgical therapy may not be appropriate for all patients in this group. Since it is difficult to determine the causation of urinary incontinence on the basis of symptoms alone, urodynamic studies can be helpful in the evaluation of incontinent patients. This is especially important in female patients with Parkinson disease who may have detrusor instability alone or in addition to anatomic stress incontinence.
The gases produced in gamma and heavy-ion radiolysis of poly(methyl methacrylate)

Abstract The production of CO, CO2, H2 and CH4 gases in the γ-radiolysis and heavy-ion radiolysis of poly(methyl methacrylate) (PMMA) was investigated. It was found that the dynamic evolution of the radiolytic gases from the polymer surface is controlled by molecular diffusion in the polymer matrix. Diffusion coefficients were extracted by model fits to the observed temporal profiles. The gas yields were determined as a function of the linear energy transfer (LET) in the range of 0.2–830 eV/nm. It was found that for heavy-ion irradiations the total gas yield increases significantly when the LET increases above 80 eV/nm. The results clearly show that the degradation mechanisms of PMMA are affected by LET. It appears that H2 and CH4 are formed from precursors different than those leading to CO and CO2. The LET dependence suggests that the latter two products are not completely formed from a common precursor, which has been previously proposed.
Taxonomy of the Archigregarinorida and Selenidiidae (Protozoa, Apicomplexa)*

SYNOPSIS. The gregarine order Archigregarinorida is redefined. The new family Selenidioididae is established in it, containing the genera Selenidioides n. g. with 11 species, Meroselenidium with 1 and Merogregarina with 1. The new family Exoschizonidae is also established in it, with 1 genus, Exoschizon, containing 1 species. The family Selenidiidae is transferred to the order Eugregarinorida in a new superfamily, Lecudinicae, and redefined to exclude the presence of merogony. As redefined, the family Selenidiidae contains the genera Selenidium with 33 species, Selenocystis with 1 and Ditrypanocystis with 2. The following new species are named: Selenidioides fanthami, S. hawesi, Selenidium mackinnonae, S. martinensis, S. rayi, Ditrypanocystis coxi. The following new combinations are introduced: Selenidioides axiferens, S. caulleryi, S. giganteum, S. hollandei, S. intraepitheliale, S. mesnili, S. metchnikovi, S. potamillae, S. sipunculi, Selenidium synaptae. In addition, the septate form from Cirratulus cirratus that was named Polyrhabdina cirratulus by Bogolepova (2) is renamed P. bogolepovae n. sp.
Contact-impact simulations on massively parallel SIMD supercomputers

The implementation of explicit finite element methods with contact-impact on massively parallel SIMD computers is described. The basic parallel finite element algorithm employs an exchange process which minimizes interprocessor communication at the expense of redundant computations and storage. The contact-impact algorithm is based on the pinball method in which compatibility is enforced by preventing interpenetration on spheres embedded in elements adjacent to surfaces. The enhancements to the pinball algorithm include a parallel assembled surface normal algorithm and a parallel detection of interpenetrating pairs. Some timings with and without contact-impact are given.
Synthesis and characterization of novel crown ether containg copolymers Ru catalyzed copolymerization of 4′-acetylbenzocrown ethers with α,ω-dienes

Ruthenium catalyzed step growth copolymerization of 4′-acetylbenzo-15-crown-5 and 4′-acetylbenzo-18-crown-6 and α,ω-dienes such as 1,3-divinyltetramethyldisiloxane or 3,3,6,6-tetramethyl-3,6-disila-1,7-octadiene give novel copolymers which incorporate crown ethers into the polymer backbone in a regular manner. The synthesis of these thermally stable copolymers and their characterization is reported. Lithium cation crown complexes have been formed.
Corrosion behavior of a duplex stainless steel under cyclic loading: a scanning Kelvin probe force microscopy (SKPFM) based microscopic study

Corrosion fatigue behavior of the duplex stainless steel AISI 2205 was studied by the scanning Kelvin probe force microscopy (SKPFM) in the ambient temperature and pressure condition (25 °C, one standard atmospheric pressure). Surface-polished AISI 2205 samples were subject to a cyclic tensile stress while immersed in a 0.5 M NaCl solution. At specified time intervals, surface Volta potential of the samples was measured using the SKPFM in an oxygen and water regulated environment. The steel samples demonstrated a map of potentials with high contrasts between ferritic and austenitic grain domains, which was then linked to the actual corrosion potential (w.r.t. a saturated calomel electrode—SCE) based on a rigorous calibration procedure. The corrosion fatigue behavior of AISI 2205 was studied by comparing the SKPFM-measured Volta potentials of the same sample under applied cyclic strain and under no applied cyclic strain. It was found that AISI 2205 became more prone to corrosion when the applied tensile strain exceeds one percent (1 %).
Sharp Inequalities for Weyl Operators and Heisenberg Groups

We study inequalities in harmonic analysis in the context of non-commutative non-compact locally compact groups. Our main result is the determination of the best constant in the Hausdorff-Young inequality for Heisenberg groups. We also obtain the somewhat surprising fact that the resulting sharp inequality does not admit any extremal functions. These results are obtained after a detailed study of the operators which occur in the Fourier decomposition of the regular representation of the Heisenberg groups. These are called Weyl operators and are of independent interest. We also obtain bounds for the best constants in the Hausdorff-Young inequality and in Young's inequality on semi-direct product groups, including non-unimodular groups. In particular, for real nilpotent groups of dimension n those best constants are shown to be dominated by the corresponding best constants for IR n. Although some of our preliminary lemmas are valid for all values ofp~(1, 2) the methods we use for our main results require that p belong to the sequence 4/3, 6/5, 8/7 ..... i.e. that p', the conjugate index, be an even integer. The contents of this paper are as follows. In Section 1 we discuss Weyl operators and determine, for p' even, the best constant in a Hausdorff-Young type inequality (Theorem 1). We also show the non-existence of extremal functions for this inequality. In Section 2 we prove some general results for locally compact groups which includes a form of Young's inequality for convolution appropriate for non-unimodular groups. This is applied to arbitrary semi-direct products. Then using a duality argument which relates the inequalities of Young and of Hausdorff-Young we obtain bounds for the Hausdorff-Young inequality (Theorem 2) on unimodular semi-direct product groups (for p' even). An interesting consequence of these results is that for a connected simply connected real nilpotent Lie group of dimension n, the best constants in the inequalities of Young and Hausdorff-Young are dominated by the corresponding best constants for IR n. In Section 3 we show (Theorem 3), using the theory of Weyl operators developed
Comparison of a bioassay and a liquid chromatography-fluorescence-mass spectrometryn method for the detection of incurred enrofloxacin residues in chicken tissues

Abstract Regulatory monitoring for most antibiotic residues in edible poultry tissues is often accomplished with accurate, although expensive and technically demanding, chemical analytical techniques. The purpose of this study is to determine if a simple, inexpensive bioassay could detect fluoroquinolone (FQ) residues in chicken muscle above the FDA established tolerance (300 ppb) comparable to a liquid chromatography-fluorescencemass spectrometryn method. To produce incurred enrofloxacin (ENRO) tissues (where ENRO is incorporated into complex tissue matrices) for the method comparison, 40-d-old broilers (mixed sex) were orally dosed through drinking water for 3 d at the FDA-approved dose of ENRO (50 ppm). At the end of each day of the 3-d dosing period and for 3 d postdosing, birds were sacrificed and breast and thigh muscle collected and analyzed. Both methods were able to detect ENRO at and below the tolerance level in the muscle, with limits of detection of 26 ppb (bioassay), 0.1 ppb for ENRO, and 0.5 ppb for the ENRO metabolite, ciprofloxacin (liquid chromatography-fluorescence-mass spectrometryn). All samples that had violative levels of antibiotic were detected by the bioassay. These results support the use of this bioassay as a screening method for examining large numbers of samples for regulatory monitoring. Positive samples should then be examined by a more extensive method, such as liquid chromatography-fluorescence-mass spectrometryn, to provide confirmation of the analyte.
A structural constitutive model for chemically treated planar tissues under biaxial loading

Chemically treated, biologically derived soft collagenous tissues are used extensively in medical devices. To enable prosthesis design through computational methods, physically realistic constitutive models are required. In the present study, a structural approach was utilized that incorporated experimentally measured angular distribution of collagen fibers. Using biaxial mechanical data from our previous study (Annals of Biomedical Engineering, vol. 26(5), pp. 892–902, 1998), the effective fiber and matrix stress–strain responses were predicted. The agreement with the experimental data supported the assumption that the mechanical effects of chemical treatment are equivalent to the addition of an isotropic elastic matrix. An important utility of this model is its ability to separate the effects of chemical treatment on the fibers and matrix. Applications of this approach include utilization in the design of novel chemical treatments that produce specific mechanical responses, the study of fatigue damage, and finite element implementation for tissue engineering scaffold design.
Low-angle faulting and the origin of Kettle dome, a metamorphic core complex in northeastern Washington

The low-angle, eastward-dipping Kettle River fault has been mapped for >45 km along the eastern flank of Kettle dome. The fault juxtaposes lower-plate, mylonitic, sillimanite-grade metamorphic rocks against upper-plate, greenschist-grade metamorphic rocks and unmetamorphosed but folded Eocene volcanic and sedimentary rocks. The geometry of high-angle listric(?) faults, which cut upper-plate rocks, suggests that the upper plate moved eastward relative to the lower plate. Cataclasis and chloritization spatially related to the Kettle River fault cut the mylonitic foliation in the lower plate, indicating that the gneisses in the lower plate were not part of a hot, mobile diapir during at least the latest stage of their “emplacement.” The similarity of the Kettle River fault to the folded Newport fault along the northern contact of Spokane dome suggests that these faults postdate the mylonitization of the lower plate but predate regional doming.
Detection of JC virus DNA in peripheral lymphocytes from patients with and without progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) results from lytic infection of oligodendrocytes by JC virus (JCV). Although JCV has been identified in mononuclear cells in bone marrow and hematogenous dissemination of the virus to the central vervous system has been suspected, JCV has never been clearly demonstrated in the peripheral circula-tion. Using polymerase chain reaction technology, we examined peripheral lymphocytes of 19 patients with brain biopsy–proven PML for the JCV genome. Two non-PML control groups, consisting of 26 patients seropositive for human immunodeficiency virus type 1 (HIV-1) and 30 immunocompetent patients with Parkinson's disease, were also examined for the presence of the JCV genome in lymphocytes. Cerebrospinal fluid from 10 patients with PML was exmimined for the presence of the JCV genome as well. The JCV genome was detected in the lymphocytes of 89% (17) of the patients with PML, 38% (10) of the HIV-1–seropositive patients without PML, and none of the patients with Parkinson's disease. Sequencing of the JCV regulatory region from the lymphocytes of three patients revealed the prototype MAD-1 strain of JCV in one patient with PML, a MAD-4 strain in a second patient with PML, and a slightly modified MAD-4 strain in an HIV-1–positive patient without PML. Only 3 of 10 patients with PML who had JCV detected in lymphocytes had the JCV genome in their cerebrospinal fluid. These results demonstrate that the JCV genome can be found in circulating lymphocytes from patients with PML and suggest that lymphocytes are an important vector for hematogenous dissemination of JCV to the central nervous system. We also identified the JCV genome in the lymphocytes of a group of HIV-1–seropositive patients with no clinical evidence of PML, suggesting that they may be at risk for development of PML and can be identified in a presymptomatic state.
Waste minimization by process modification

Abstract A simulation of the Sohio process for the production of acrylonitrile from the catalytic ammoxidation of propylene has been performed, using published kinetic and thermodynamic data to illustrate the concepts of pollution prevention by process modification. The study has determined the reaction parameters which will minimize the production of by-products while maintaining the conversion of propylene above 80%. The reaction parameters studied were reactor type (plug flow reactor [PFR], continuous stirred tank reactor [CSTR], and fluidized bed reactor [FBR]), reaction temperature, residence time, and entering feed temperature. The minimum byproducts were produced in an FBR operating at 450°C at a residence time of 7 seconds for a conversion of 81%.
Algorithm for radiometrically accurate nonuniformity correction with arbitrary scene motion

This paper describes a major generalization of a recently reported radiometrically-accurate algebraic nonuniformity correction (NUC) algorithm. The original technique was capable of accurately estimating the bias nonuniformity from a sequence of pairs of images exhibiting strictly one-dimensional (1D) subpixel shifts. The new technique relaxes the subpixel 1D shift constraint to arbitrary two-dimensional (2D) motion, which can be either sub-pixel or super-pixel. The 2D technique relies on calibrating only rows and columns on the perimeter of the array, which in turn, provides the algorithm with the necessary initial conditions to recursively estimate the bias values in the entire array. In this way, radiometric NUC can be achieved non-disruptively, as needed, without disturbing the functionality of the interior array elements. The 2D algorithm is highly localized in time and space lending itself to near real-time implementation. Radiometric NUC can be achieved with a relatively low number of frames (typically about 10 frame pairs). Moreover, as in its earlier 1D version, the performance of the 2D algorithm is shown to be insensitive to spatial diversity in the scene. This paper will address the performance of the 2D technique using real infrared data.
The peritrophic membrane of the gastropodMegathura crenulata: structure, composition, and site of formation

Peritrophic membranes (PMs) are acellular layered structures secreted around ingested materials by the gut epithelium. Most studies on PMs have focused on those of insects and crustaceans due to their potential ability to block the movement of pathogens from ingested materials into the body, and their possible use as unique targets relevant to pest management. While PMs are known to occur in other taxa, their distribution is spotty and little is known about their role in these other species. The gastropod Megathura crenulata produces a true PM, which has a chitinous matrix that makes up nearly half its wet weight. Unlike arthropod PMs, which are released by delamination from the microvilli of their gut cells, the chitinous matrix of the M. crenulata PM is secreted from epithelial cells lining most regions of its gut. Although its mode of synthesis is unique, it may serve the same functions as proposed for other PMs, including regulating diffusion, binding metabolites, restricting protease activity, blocking pathogens, and providing lubrication. In arthropods, numerous proteins with chitin-binding specificities have been identified, consistent with the proposed functions. Analysis of PMs in M. crenulata showed several integral proteins associated with the membrane, suggesting that the PM in this mollusc may be involved in complex functions like those seen in the arthropods.
Success of Slimy Sculpin Reintroductions in Minnesota Trout Streams: Influence of Feeding and Diets

Abstract Slimy sculpin Cottus cognatus are being reintroduced into coldwater streams in southeastern Minnesota to restore native biotic diversity and provide forage for large trout, but success has been variable. We examined slimy sculpin diets and prey consumption in a series of field and laboratory experiments to assess the potential role of invertebrate prey in affecting reintroduction success. Sculpin consumed 35 different types of prey in the field, but frequency of occurrence was highest and preferences (Ivlev's selectivity index) strongest for Diptera larvae and Amphipoda. Benthic samples indicated that preferred prey items were abundant in most streams. In 24-h feeding experiments, sculpin typically consumed 5 to 15 prey/day, and exhibited selective feeding for Amphipoda (Gammarus), Isopoda (Asellus), and Ephemeroptera (Baetis) while rejecting Trichoptera (Brachycentrus) and Gastropoda (Physella). Sculpin are euryphagous and flexible to varying prey availability in different streams, demonstrating...
A review of animal phosphofructokinase isozymes with an emphasis on their physiological role

Phosphofructokinase (PFK) isozymes and their physiological significance have been the focus of extensive research. The majority of this work has been centered around the PFK isozymes of rat, human and rabbit tissues. Consequently, this review emphasizes these studies. Additionally, a review of PFK isozymes in chickens, mice, guinea pig, and pig is presented. The relationship of the properties of each PFK isozyme in different tissues to the rates of glycolysis and/ or gluconeogenesis in those tissues is discussed where possible. Moreover, the contribution of the different PFK isozymes to alterations of the glycolytic rate in various tissues is discussed in relationship to variations in nutritional, hormonal, developmental or pathological status of the animal.
Individualized prognosis for melanoma patients

The clinical course of malignant melanoma is notoriously variable. Current approaches to prognostication allow assignment to risk categories but do not permit accurate assessment of prognosis on an individual patient basis. We analyzed a melanoma histology database that comprises 1,042 sequential melanoma patients evaluated by A.J.C. at UCLA between 1980 and 1990 for 30 separate variables according to a standard protocol. After censoring for absent data, a univariate Cox model analysis was performed that showed 20 individual variables that were significantly linked to clinical outcome. A step-up multivariate analysis was then performed. The combined analysis shows 5 variables: gender, site of primary, age relative to 60 years, Breslow thickness, and presence and width of ulceration to be linked to survival. Probability of survival is calculated using a 2-step approach. The survival-linked variables are multiplied to give an individualized risk score. This is converted into probability of survival by the formula .987^ (risk score) for 3-year survival, .975^ (risk score) for 5-year survival, and .960^ (risk score) for 10-year survival. Thus, a 55-year-old woman with a 1.8-mm nonuclerated melanoma on the leg would have a risk score of (1 × 1 × 1 × 2 × 1) = 2 and a predicted probability of survival at 5 years of .975^2 (95%) and at 10 years of .960^2 (92%). We used similar techniques to develop individualized risk scores for likelihood of recurrence. The significant variables in this case are anatomic site of the primary melanoma, melanoma subtype, Breslow thickness, and presence and width of ulceration. The formulae for likelihood of recurrence at different periods after initial surgical removal of the primary melanoma are at 3 years, .979^(risk score); at 5 years, .971^(risk score); and at 10 years, .957^(risk score). This relatively simple approach to prognostication uses readily available demographic information and is likely to be more accurate than single-factor analysis.
Characteristics and processing of seismic data collected on thick, floating ice: Results from the Ross Ice Shelf, Antarctica

Coincident reflection and refraction data, collected in the austral summer of 1988/89 by Stanford University and the Geophysical Division of the Department of Scientific and Industrial Research, New Zealand, imaged the crust beneath the Ross Ice Shelf, Antarctica. The Ross Ice Shelf is a unique acquisition environment for seismic reflection profiling because of its thick, floating ice cover. The ice shelf velocity structure is multilayered with a high velocity‐gradient firn layer constituting the upper 50 to 100 m. This near surface firn layer influences the data character by amplifying and frequency modulating the incoming wavefield. In addition, the ice‐water column introduces pervasive, high energy seafloor, intra‐ice, and intra‐water multiples that have moveout velocities similar to the expected subseafloor primary velocities. Successful removal of these high energy multiples relies on predictive deconvolution, inverse velocity stack filtering, and frequency filtering. Removal of the multiples reveals...
A conceptual framework for restoration of threatened plants: the effective model of American chestnut (Castanea dentata) reintroduction

'Summary' I. 'Castanea dentata as a model at the intersection of reintroduction biology and restoration ecology' II. 'Technological approaches for recovery of Castanea dentata' III. 'Ecology of the historically dominant Castanea dentata in contemporary forests' IV. 'Societal challenges for successful reintroduction of Castanea dentata' V. 'Conclusions' 'Acknowledgements' References Summary We propose a conceptual framework for restoration of threatened plant species that encourages integration of technological, ecological, and social spheres. A sphere encompasses ideas relevant to restoration and the people working within similar areas of influence or expertise. Increased capacity within a sphere and a higher degree of coalescing among spheres predict a greater probability of successful restoration. We illustrate this with Castanea dentata, a foundation forest tree in North America that was annihilated by an introduced pathogen; the species is a model that effectively merges biotechnology, reintroduction biology, and restoration ecology. Because of C. dentata's ecological and social importance, scientists have aggressively pursued blight resistance through various approaches. We summarize recent advancements in tree breeding and biotechnology that have emerged from C. dentata research, and describe their potential to bring new tools to bear on socio-ecological restoration problems. Successful reintroduction of C. dentata will also depend upon an enhanced understanding of its ecology within contemporary forests. We identify a critical need for a deeper understanding of societal influences that may affect setting and achieving realistic restoration goals. Castanea dentata may serve as an important model to inform reintroduction of threatened plant species in general and foundation forest trees in particular.
Two-dimensional moisture flow-soil deformation model for application to pavement design

Seasonal cycles of wetting and drying in highway subgrade soils induce corresponding cycles of soil swelling and shrinkage that contribute to roughness and loss of serviceability of pavements. The design of defensive measures to mitigate the effects of this process requires a realistic model of moisture diffusion and associated swelling and shrinkage of soil. A Windows-based two-dimensional finite element program, FLODEF, is presented; it performs a sequentially coupled flow-displacement analysis for the prediction of vertical movement in highway subgrade soils. The theoretical formulations of moisture flow and stress-deformation components of the model are introduced first. Parametric studies illustrate capabilities of the model to evaluate the effectiveness of vertical moisture barriers, horizontal barriers, soil replacement or improvement, and paved medians in reducing swell-shrink deformations beneath highway pavements.
Microtubule-associated proteins from antarctic fishes

Microtubules and presumptive microtubule-associated proteins (MAPs) were isolated from the brain tissues of four Antarctic fishes (Notothenia gibberifrons, N. coriiceps neglecta, Chaenocephalus aceratus, and a Chionodraco sp.) by means of a taxol-dependent, microtubule-affinity procedure (cf. Vallee: Journal of Cell Biology 92:435-442, 1982). MAPs from these fishes were similar to each other in electrophoretic pattern. Prominent in each preparation were proteins in the molecular weight ranges 410,000-430,000, 220,000-280,000, 140,000-155,000, 85,000-95,000, 40,000-45,000, and 32,000-34,000. The surfaces of MAP-rich microtubules were decorated by numerous filamentous projections. Exposure to elevated ionic strength released the MAPs from the microtubules and also removed the filamentous projections. Addition of fish MAPs to subcritical concentrations of fish tubulins at 0-5 degrees C induced the assembly of microtubules. Both the rate and the extent of this assembly increased with increasing concentrations of the MAPs. Sedimentation revealed that approximately six proteins, with apparent molecular weights between 60,000 and 300,000, became incorporated into the microtubule polymer. Bovine MAPs promoted microtubule formation by fish tubulin at 2-5 degrees C, and proteins corresponding to MAPs 1 and 2 co-sedimented with the polymer. MAPs from C. aceratus also enhanced the polymerization of bovine tubulin at 33 degrees C, but the microtubules depolymerized at 0 degrees C. We conclude that MAPs are part of the microtubules of Antarctic fishes, that these proteins promote microtubule assembly in much the same way as mammalian MAPs, and that they do not possess special capacities to promote microtubule assembly at low temperatures or to prevent cold-induced microtubule depolymerization.
Should disks be speed demons or brainiacs

Disk drives play a critical role on the performance of I/O intensive applications. Over the years, disk drive performance has grown as a result of advances in magnetic recording density and faster rotational speeds. In essence, the performance driver in disks has been the data rate. In this paper, we show that data rate is going to be increasingly difficult to optimize, due to power/thermal constraints. We argue that disk drive designers should instead focus their efforts on providing more computational capabilities that data intensive applications could leverage in order to boost performance. We also discuss the scope for provisioning powerful processors inside disk drives to provide these computational capabilities.
DNA replication: changing faces, trading places.

Mutually exclusive post-translational modifications of flap endonuclease 1 (FEN1) regulate its binding to proliferating cell nuclear antigen (PCNA) and govern its various modes of DNA interaction during DNA replication and repair.
Unusual properties of the DNA from Xanthomonas phage XP-12 in which 5-methylcytosine completely replaces cytosine.

Abstract Xanthomonas phage XP-12 contains 5-methylcytosine completely replacing cytosine. This substitution confers several unusual properties upon XP-12 DNA. The buoyant density of XP-12 DNA in CsCl gradients is 1.710 g/cm3, 0.016 g/cm3 lower than that expected for a normal DNA with the same percentage of adenine plus thymine. The melting temperature for XP-12 DNA in 0.012 M Na+ is the highest reported for any naturally occurring DNA, 83.2°C, 6.1°C higher than that of normal DNAs with the same percentage of adenine plus thymine. Unlike the minor amounts of 5-methylcytosine found in most plant and animal DNAs, the 5-methylcytosine residues of XP-12 derive their methyl group from the 3-carbon of serine instead of from the thiomethyl carbon of methionine.
The Elevated-Temperature Creep Behavior of Boron-Modified Ti-6Al-4V Alloys

This work investigated the effect of nominal boron (B) additions of 0.1 mass% and 1 mass% on the elevated-temperature (673–728 K) tensile-creep deformation behavior of a Ti-6Al-4V(mass%) alloy for applied stresses between 400–600 MPa. The alloys were evaluated in the as-cast and cast-then-extruded conditions. Boron additions resulted in a dramatic refinement of the as-cast grain size and TiB whisker volume percents of approximately 0.6 and 6.0 for the Ti-6Al-4V-0.1B and Ti-6Al-4V-1B alloys, respectively. The extrusions were performed in the � phase field and resulted in the TiB-phase whiskers aligning in the extrusion direction. The creep resistance of the as-cast alloys significantly improved with increased B concentration, where around an order of magnitude decrease in the secondary creep rate was observed between the Ti-6Al-4V-1B and Ti-6Al-4V as-cast alloys. Grain refinement due to the B addition did not deleteriously affect the creep resistance in the temperature and stress ranges considered, where dislocation creep was suggested to be the dominant secondary-creep mechanism. The enhanced creep resistance was attributed to load sharing by the TiB whiskers. For the same nominal B contents, the cast-then-extruded alloys exhibited significantly greater creep resistance and tensile strength than the as-cast alloys. This was explained to be an effect of the � -phase texture and the decreased lath spacing in the cast-then-extruded alloys compared with the as-cast alloys. The cast-then-extruded alloys exhibited four times lower lath widths than the as-cast alloys, and the � -phase was strongly textured such that the basal plane was predominately oriented perpendicular to the extrusion axis. Comparing the cast-then-extruded alloys, the Ti-6Al-4V alloy exhibited the greatest creep resistance. Overall the � -phase consisted of approximately 80% of the microstructure, and the � -phase texture appeared to be more dominant to the creep resistance and tensile strength than the small volume percent of TiB-phase in the microstructure. Although B is not necessary to optimize the elevated-temperature creep performance of the Ti-6Al-4V alloy, when boron was present, greater boron additions increased the creep resistance. In-situ creep observations of the surface indicated that the TiB whisker cracking occurred prior to slip and void formation in the � þ � phases. This was followed by �=� interface cracking and ductile failure of the � þ � microstructure. [doi:10.2320/matertrans.MF200914]