cssi/SciSciGPT-SciSciNet huggingface dataset:
Melt quenching and coolability by water injection from below: Co-injection of water and non-condensable gas

Abstract The interaction and mixing of high-temperature melt and water is the important technical issue in the safety assessment of water-cooled reactors to achieve ultimate core coolability. For specific advanced light water reactor (ALWR) designs, deliberate mixing of the core melt and water is being considered as a mitigative measure, to assure ex-vessel core coolability. The goal of our work is to provide the fundamental understanding needed for melt–water interfacial transport phenomena, thus enabling the development of innovative safety technologies for advanced LWRs that will assure ex-vessel core coolability. The work considers the ex-vessel coolability phenomena in two stages. The first stage is the melt quenching process and is being addressed by Argonne National Lab and University of Wisconsin in modified test facilities. Given a quenched melt in the form of solidified debris, the second stage is to characterize the long-term debris cooling process and is being addressed by Korean Maritime University via test and analyses. In this paper, experiments on melt quenching by the injection of water from below are addressed. The test section represented one-dimensional flow-channel simulation of the bottom injection of water into a core melt in the reactor cavity. The melt simulant was molten lead or a lead alloy (Pb–Bi). For the experimental conditions employed (i.e., melt depth and water flow rates), it was found that: (1) the volumetric heat removal rate increased with increasing water mass flow rate and (2) the non-condensable gas mixed with the injected water had no impairing effect on the overall heat removal rate. Implications of these current experimental findings for ALWR ex-vessel coolability are discussed.
Professionalism, organizational commitment and job satisfaction in an accounting organization

Abstract With growth in the number of professionals employed in organizations, concern has been expressed over potential conflict between the professionalism of these employees and their commitment to the organization. Empirical studies examining the relationships between professionalism, organizational commitment and job satisfaction have reported inconsistent results. This paper examines these variables in an organization setting involving several field offices of a “Big Eight” U.S. accounting firm. Accountants who reported high levels of professionalism also reported high levels of organizational commitment. Additionally, both professionalism and organizational commitment were strongly related to job satisfaction.
Soil-to-Human Mineral Transmission with an Emphasis on Zinc, Selenium, and Iodine

Soil-to-crop mineral transmission was first investigated in the 1960s and 1970s, and a large body of evidence now documents transmission of minerals from soil to crops. A smaller group of papers illustrates that soil concentrations of zinc, selenium, and iodine impact human intake of these important minerals, and even human mineral status. Despite this fact, estimates of human mineral intake or human mineral deficiency rates often rely on nutrient composition tables that assume a single mineral concentration for every crop or food worldwide. Public health policy-makers rarely discuss the role of soils in driving human mineral deficiencies, and scientists who study soil degradation tend to focus on the yield and production consequences of macronutrient depletion, ignoring the health consequences of micronutrient depletion. By reviewing and re-considering four decades of literature on soil-to-human mineral transmission, we may realize new points of intervention within the food system for addressing mineral deficiency in human populations.
Nano-opto-mechanical characterization of neuron membrane mechanics under cellular growth and differentiation.

We designed and fabricated silicon probe with nanophotonic force sensor to directly stimulate neurons (PC12) and measured its effect on neurite initiation and elongation. A single-layer pitch-variable diffractive nanogratings was fabricated on silicon nitride probe using e-beam lithography, reactive ion etching and wet-etching techniques. The nanogratings consist of flexure folding beams suspended between two parallel cantilevers of known stiffness. The probe displacement, therefore the force, can be measured through grating transmission spectrum. We measured the mechanical membrane characteristics of PC12 cells using the force sensors with displacement range of 10 μm and force sensitivity 8 μN/μm. Young’s moduli of 425 ± 30 Pa are measured with membrane deflection of 1% for PC12 cells cultured on polydimethylsiloxane (PDMS) substrate coated with collagen or laminin in Ham’s F-12K medium. In a series of measurements, we have also observed stimulation of directed neurite contraction up to 6 μm on extended probing for a time period of 30 min. This method is applicable to measure central neurons mechanics under subtle tensions for studies on development and morphogenesis. The close synergy between the nano-photonic measurements and neurological verification can improve our understanding of the effect of external conditions on the mechanical properties of cells during growth and differentiation.
Incompressibility of the solid matrix of articular cartilage under high hydrostatic pressures

Abstract The objective of this study was to test the hypothesis that the organic solid matrix of articular cartilage is incompressible under physiological levels of pressure. Due to its anisotropic swelling behavior, an anisotropic version of the biphasic theory was used to predict the deformation and internal stress fields. This theory predicts that, under hydrostatic loading of cartilage via a pressurized external fluid, a state of uniform hydrostatic fluid pressure exists within the tissue regardless of the anisotropic nature of the solid matrix. The theory also predicts that if the solid matrix is intrinsically incompressible, the tissue will not deform under hydrostatic loading conditions. This prediction, i.e., no deformation, was experimentally tested by subjecting specimens of normal bovine articular cartilage to hydrostatic pressures. A new high pressure hydrostatic loading chamber was designed and built for this purpose. It was found that normal bovine articular cartilage, when subject to hydrostatic pressures up to 12 MPa, does not deform measurably. This experimental finding supports one of the fundamental assumptions of the biphasic theory for cartilage, i.e., the organic solid matrix of the tissue is intrinsically incompressible when loaded within the normal physiologic range of pressures. Hydrostatic loading has often been used in cartilage explant cultures for tissue metabolism studies. The findings of this study provides an accurate method to calculate the states of stress acting on the fluid and solid phases of the tissue in these hydrostatically loaded explant culture experiments, and suggest that tissue deformation will be minimal under pure hydrostatic pressurization.
Structure-based predictions broadly link transcription factor mutations to gene expression changes in cancers

Thousands of unique mutations in transcription factors (TFs) arise in cancers, and the functional and biological roles of relatively few of these have been characterized. Here, we used structure-based methods developed specifically for DNA-binding proteins to systematically predict the consequences of mutations in several TFs that are frequently mutated in cancers. The explicit consideration of protein–DNA interactions was crucial to explain the roles and prevalence of mutations in TP53 and RUNX1 in cancers, and resulted in a higher specificity of detection for known p53-regulated genes among genetic associations between TP53 genotypes and genome-wide expression in The Cancer Genome Atlas, compared to existing methods of mutation assessment. Biophysical predictions also indicated that the relative prevalence of TP53 missense mutations in cancer is proportional to their thermodynamic impacts on protein stability and DNA binding, which is consistent with the selection for the loss of p53 transcriptional function in cancers. Structure and thermodynamics-based predictions of the impacts of missense mutations that focus on specific molecular functions may be increasingly useful for the precise and large-scale inference of aberrant molecular phenotypes in cancer and other complex diseases.
A hybrid tool for the performance evaluation of NUMA architectures

We present a system for describing and solving closed queuing network models of the memory access performance of NUMA architectures. The system consists of a model description language, solver engines based upon both discrete event simulation and derivatives of the Mean Value Analysis (MVA) algorithrn, and a model manager used to translate model descriptions to the forms required by the solvers. A single model description file is used to describe the essential elements that characterize the NUMA system and its workload. During a single simulation or MVA modeling run it is easy to dynamically vary elements of the system model, such as mean device service times, elements of the workload model such as cache miss rates, or both. Use of the extremely fast, but approximating, MVA solvers to interpolate between design points computed by the slower simulator allows the analyst to obtain detailed and accurate results in minimal time.
Infection of female primary lower genital tract epithelial cells after natural pseudotyping of HIV-1: possible implications for sexual transmission of HIV-1.

The global AIDS pandemic continues to expand and in some regions of the world, such as southern Africa, the prevalence of HIV-1 infection exceeds 20%. The devastating spread of the virus in young women in these countries appears disproportional to overall risk of infection. Regions with high prevalence of HIV-1 are often also highly endemic for other pathogenic viruses including HSV, CMV and HTLV. We propose that acquisition by HIV-1 of the envelope glycoproteins of other viruses, in a process we call “natural pseudotyping,” expands the cellular tropism of HIV-1, enabling it to infect female genital epithelial cells directly and thereby dramatically increasing risk of infection during sexual intercourse. In this proof-of-concept study, we demonstrate that when HIV-1 co-infects T cells along with the gammaretrovirus xenotropic murine leukemia virus-related virus (XMRV), progeny HIV-1 particles are produced capable of infecting primary vaginal, ectocervical and endocervical epithelial cells. These cell types are normally resistant to HIV-1 infection. Infection of primary genital cells was neutralized by antisera against the XMRV glycoprotein, confirming that infection was mediated by the XMRV glycoprotein acquired through pseudotyping of HIV. Inhibition by AZT showed that active replication of HIV-1 occurred in these cells and ruled out non-specific endocytic uptake of the virus. These results demonstrate that natural pseudotyping can expand the tropism of HIV-1 to include genital epithelial cells and have potential implications for sexual transmission of the virus.
State-resolved predissociation dynamics of the formyloxyl radical

Dissociation dynamics of the deuterated formyloxyl radical, DCO2, were studied by photoelectron-photofragment coincidence spectroscopy of DCO2-. Photodetachment at 4.27 eV accesses the three lowest-lying electronic states ((2)A(1), B-2(2), and (2)A(2)) of DCO2, leading to vibrational excitation dominated by the (2)A(1) state O-C-O bending mode. Predissociation leads to bending excitation in the CO2 products as observed in the product translational energy distribution. Gating the coincidence spectra by electron kinetic energy for each predissociated vibrational mode in the radical provides a direct measure of the CO2 bending vibration (v(2)) product state distribution, revealing substantially more excitation than ab initio quantum-dynamics calculations predict. (C) 2013 Elsevier B.V. All rights reserved.
Fluorescence elimination in x-ray diffractometry with solid state detectors

Abstract Solid state x-ray detectors exhibit sufficient energy resolution (200–400 eV.) to discriminate completely against sample fluorescence and to eliminate the need for a Kβ filter. The system provides peak to background ratios similar to those obtained using a focusing monochromator, and peak intensities greater than can be obtained from a gas filled proportional counter with a Kβ filter.
The pandemic potential of Nipah virus

Nipah virus, a paramyxovirus whose wildlife reservoir is Pteropus bats, was first discovered in a large outbreak of acute encephalitis in Malaysia in 1998 among persons who had contact with sick pigs. Apparently, one or more pigs was infected from bats, and the virus then spread efficiently from pig to pig, then from pigs to people. Nipah virus outbreaks have been recognized nearly every year in Bangladesh since 2001 and occasionally in neighboring India. Outbreaks in Bangladesh and India have been characterized by frequent person-to-person transmission and the death of over 70% of infected people. Characteristics of Nipah virus that increase its risk of becoming a global pandemic include: humans are already susceptible; many strains are capable of limited person-to-person transmission; as an RNA virus, it has an exceptionally high rate of mutation: and that if a human-adapted strain were to infect communities in South Asia, high population densities and global interconnectedness would rapidly spread the infection. Appropriate steps to estimate and manage this risk include studies to explore the molecular and genetic basis of respiratory transmission of henipaviruses, improved surveillance for human infections, support from high-income countries to reduce the risk of person-to-person transmission of infectious agents in low-income health care settings, and consideration of vaccination in communities at ongoing risk of exposure to the secretions and excretions of Pteropus bats.
Influence of Diet Composition on Hepatic Lipid Deposition in Two Lines of Australorps Selected for Liver Fat Differences

Abstract This investigation was conducted to determine if the level of liver fat in Black Australorp laying hens, which had been selected over several generations for high or low liver fat content, would respond to changes in diet composition similar to the response of commercial strains of White Leghorns. In the first experiment, the two selected lines were fed either a corn-soybean diet (CS) or an tsonitrogenous and isoenergetic diet containing 4.89% each of fish meal, alfalfa meal, and torula yeast (FAY) for 6 weeks. Liver lipid was significantly higher for the high (19.4%) than for the low line (10.8%), but the FAY diet did not significantly affect this parameter. In a second 6-week experiment, the high and low lines of Black Australorps and unselected commercial White Leghorn hens were fed either the CS diet or one containing 14.67% distillers dried grains with solubles (DDGS). The DDGS significantly reduced both liver lipid and relative liver weight in Leghorns but not in the low and high liver fat Black Australorp lines. These results indicate that the mechanism of hepatic lipid accumulation in the genetically selected birds is different from that caused by feeding Leghorn hens a simplified CS diet and that the high liver fat line would not be useful in delineating nutritional effects on hepatic lipid accumulation.
Simplification of a Realistic Model of IP3-induced Ca2+ Oscillations

Abstract We explore a recent mechanism for IP 3 -induced Ca 2+ oscillations based on the properties of the IP 3 receptor/Ca 2+ channel in the endoplasmic reticulum. Analysis of the differential equations reveals three essential characteristics of the mechanism: Ca 2+ -activation of Ca 2+ release, Ca 2+ -inhibition of Ca 2+ release, and activation by IP 3 . Using these features we reduce the system of differential equations from nine dynamical variables down to five, three, and ultimately two variables, the simplest of which has a structure similar to the FitzHugh-Nagumo model. The two-variable model is valid in the limit that Ca 2+ dynamics are fast. In this limit it is the receptor dynamics that are primarily responsible for setting the time scale for the oscillations, in contrast to models based exclusively on Ca 2+ -induced Ca 2+ release. The reduced equations exhibit IP 3 -induced Ca 2+ oscillations, Ca 2+ -induced Ca 2+ release, and other features similar to those seen in the full nine-variable model.
Aldehyde oxidases and dehydrogenases in antennae of five moth species

Abstract Conversion of Z11–16:A1 to its corresponding carboxylic acid was examined in male antennal extracts from Heliothis subflexa, Heliothis virescens, Heliothis zea, Manduca sexta and Spodoptera frugiperda moths. Both aldehyde dehydrogenase (ALDH) and aldehyde oxidase (AO) activities were detected by radiochromatographic assays using [3H]Z11–16:A1 as the substrate and by spectroscopic assays using Z11–16:A1 as the substrate. AO activity in each of the five moths showed a broad substrate specificity which included C4 to C18 aliphatic aldehydes and benzaldehyde. ALDH and AO enzymes from the male and female antennal extracts were identified after electrophoretic protein separation. AO enzymes were visualized on native polyacrylamide gels with formazan- or horseradish peroxidase-mediated stain coupled to the AO-catalyzed oxidation of benzaldehyde. Both sexes of most species showed intense AO-stained bands of similar mobility. Molecular subunits of potential ALDH enzymes were visualized by fluorography of SDS-PAGE-separated proteins after covalent modification by [3H](Z)-1,11-hexadecadien-3-one, a selective affinity label for ALDH. ALDH subunits appeared at 51 ± 1 kDa in antennae from males of all five species and females of three species; female H. zea and M. sexta moths lacked these characteristic ALDH subunits. These results constitute the first biochemical comparisons of coexisting ALDH and AO enzymes in antennal extracts from lepidopteran species from two families.
Inhibition of aldehyde detoxification in CNS mitochondria by fungicides.

Among the several converging factors leading to Parkinson's disease, epidemiological studies indicate a correlation between Parkinson's disease (PD) with living in a rural area and/or exposure to agricultural pesticides. In this present study, we examined the potential of multiple agricultural pesticides for their ability to inhibit the function of whole, respiring rat brain mitochondria using the oxidation of the neurotoxic lipid-aldehyde trans-4-hydroxy-2-nonenal (HNE) as a biomarker for mitochondrial aldehyde dehydrogenase (ALDH) activity in situ. We chose an arbitrary cutoff concentration of 10 μM of each pesticide. Our data demonstrate that only four of the eighteen compounds tested inhibited oxidation of HNE to trans-4-hydroxy-2-nonenoic acid (HNEAcid). These compounds included rotenone, maneb, mancozeb, and benomyl. Surprisingly, maneb, mancozeb, and benomyl did not inhibit mitochondrial respiration but inhibited the activity of purified rat ALDH2 and rat ALDH5A, enzymes found in brain mitochondria that oxidize HNE and aldehydes derived from neurotransmitters. Our data demonstrate that mitochondrial ALDHs are sensitive targets of pesticide inactivation and that pesticides such as maneb and benomyl can decrease the detoxification of lipid peroxidation derived aldehydes such as HNE and, likely, aldehydes derived from neurotransmitters.
Experimental study of the transition from forced to natural circulation in EBR-II at low power and flow

A series of tests was conducted in EBR-II which examined the dynamics of the transition from forced to natural circulation flow in a liquid-metal-cooled fast breeder reactor. Each test was initiated by abruptly tripping an electromagnetic pump which supplies 5--6 percent of the normal full operational primary flow rate. The ensuing flow coastdown reached a minimum value after which the flow increased as natural circulation was established. The effects of secondary system flow through the intermediate heat exchanger and reactor decay power level on the minimum in-core flow rates and maximum in-core temperatures were examined.
The Triassic timescale based on nonmarine tetrapod biostratigraphy and biochronology

Abstract The Triassic timescale based on nonmarine tetrapod biostratigraphy and biochronology divides Triassic time into eight land-vertebrate faunachrons (LVFs) with boundaries defined by the first appearance datums (FADs) of tetrapod genera or, in two cases, the FADs of a tetrapod species. Definition and characterization of these LVFs is updated here as follows: the beginning of the Lootsbergian LVF=FAD of Lystrosaurus ; the beginning of the Nonesian=FAD Cynognathus ; the beginning of the Perovkan LVF=FAD Eocyclotosaurus ; the beginning of the Berdyankian LVF=FAD Mastodonsaurus giganteus ; the beginning of the Otischalkian LVF=FAD Parasuchus ; the beginning of the Adamanian LVF=FAD Rutiodon ; the beginning of the Revueltian LVF=FAD Typothorax coccinarum ; and the beginning of the Apachean LVF=FAD Redondasaurus . The end of the Apachean (= beginning of the Wasonian LVF, near the beginning of the Jurassic) is the FAD of the crocodylomorph Protosuchus . The Early Triassic tetrapod LVFs, Lootsbergian and Nonesian, have characteristic tetrapod assemblages in the Karoo basin of South Africa, the Lystrosaurus assemblage zone and the lower two-thirds of the Cynognathus assemblage zone, respectively. The Middle Triassic LVFs, Perovkan and Berdyankian, have characteristic assemblages from the Russian Ural foreland basin, the tetrapod assemblages of the Donguz and the Bukobay svitas, respectively. The Late Triassic LVFs, Otischalkian, Adamanian, Revueltian and Apachean, have characteristic assemblages in the Chinle basin of the western USA, the tetrapod assemblages of the Colorado City Formation of Texas, Blue Mesa Member of the Petrified Forest Formation in Arizona, and Bull Canyon and Redonda formations in New Mexico. Since the Triassic LVFs were introduced, several subdivisions have been proposed: Lootsbergian can be divided into three sub-LVFs, Nonesian into two, Adamanian into two and Revueltian into three. However, successful inter-regional correlation of most of these sub-LVFs remains to be demonstrated. Occasional records of nonmarine Triassic tetrapods in marine strata, palynostratigraphy, conchostracan biostratigraphy, magnetostratigraphy and radioisotopic ages provide some basis for correlation of the LVFs to the standard global chronostratigraphic scale. These data indicate that Lootsbergian=uppermost Changshingian, Induan and possibly earliest Olenekian; Nonesian=much of the Olenekian; Perovkan=most of the Anisian; Berdyankian=latest Anisian? and Ladinian; Otischalkian=early to late Carnian; Adamanian=most of the late Carnian; Revueltian=early–middle Norian; and Apachean=late Norian–Rhaetian. The Triassic timescale based on tetrapod biostratigraphy and biochronology remains a robust tool for the correlation of nonmarine Triassic tetrapod assemblages independent of the marine timescale.
Inundation, sedimentation, and subsidence creates goose habitat along the Arctic coast of Alaska

The Arctic Coastal Plain of Alaska is characterized by thermokarst lakes and drained lake basins, and the rate of coastal erosion has increased during the last half-century. Portions of the coast are <1?m above sea level for kilometers inland, and are underlain by ice-rich permafrost. Increased storm surges or terrestrial subsidence would therefore expand the area subject to marine inundation. Since 1976, the distribution of molting Black Brant (Branta bernicla nigricans) on the Arctic Coastal Plain has shifted from inland freshwater lakes to coastal marshes, such as those occupying the Smith River and Garry Creek estuaries. We hypothesized that the movement of geese from inland lakes was caused by an expansion of high quality goose forage in coastal areas. We examined the recent history of vegetation and geomorphological changes in coastal goose habitat by combining analysis of time series imagery between 1948 and 2010 with soil stratigraphy dated using bomb-curve radiocarbon. Time series of vertical imagery and in?situ verification showed permafrost thaw and subsidence of polygonal tundra. Soil stratigraphy and dating within coastal estuaries showed that non-saline vegetation communities were buried by multiple sedimentation episodes between 1948 and 1995, accompanying a shift toward salt-tolerant vegetation. This sedimentation allowed high quality goose forage plants to expand, thus facilitating the shift in goose distribution. Declining sea ice and the increasing rate of terrestrial inundation, sedimentation, and subsidence in coastal estuaries of Alaska may portend a ?tipping point? whereby inland areas would be transformed into salt marshes.
NMR Determinations of Molecular Geometries in Liquid Crystal Media

The application of NMR spectroscopy in oriented media to the determination of molecular geometries is illustrated by results for three distinctly different molecules: naphthalene, ethylene oxide and spiropentane. The need for systematic application of vibrational corrections is emphasized and some of the effects associated with the different choices of solvent media are considered.
Stent-graft design: the good, the bad and the ugly.

Abstract 10 years of experience with endovascular AAA repair has yielded important information regarding the relationship between stent-graft design and stent-graft performance. Commercially available systems differ in important ways. General conclusions regarding endovascular AAA repair need to be qualified by reference to a specific system, or systems. Nevertheless, one can draw conclusions regarding the observed effects of certain design features, some of which are common to several devices. For example: tapered, trackable delivery systems (≤20 French in diameter) rarely fail to traverse tortuous iliac arteries: transmural barbs provide the most secure means of proximal attachment, column strength is of little value; proximal stent migration is becoming the primary late failure mode; modular stent-grafts are more versatile than unibody stent-grafts; fully-stented graft limbs are less prone to thrombosis than unstented graft limbs, iliac implantation and low porosity are associated with lower rates of aneurysm dilatation in the absence of endoleak (endotension); any movement between the angle of a stent and the overlying fabric will lead to graft erosion; unpolished (black) Nitinol is prone to fracture; and a long trunk/short limb combination is more stable than a short trunk/long limb combination.
An Approximate Solution for Period-m Motions in a Periodically Forced Oscillator With Quadratic Nonlinearity

The approximate analytical solutions of the period-m motions for a periodically forced, quadratic nonlinear oscillator are presented. The stability and bifurcation of such approximate solutions in the quadratic nonlinear oscillator are discussed. The bifurcation tree of period-1 to chaos is presented. Numerical simulations for period-1 to period-4 motions in such quadratic oscillator are carried out for comparison of approximate analytical solutions.
Directions in Television and Aging Research.

Following from a summary review of television and aging research studies, methodological difficulties of past investigations and needed directions for future mass communication and aging research are discussed.
The chromium-plated tabulator: institutionalizing an electronic revolution, 1954-1958

The computer promised business of the 1950s an administrative revolution. What it delivered was data processing-a hybrid of new technology and existing punched card machines, people, and attitudes. The author examines how first-generation computers were sold and purchased, and describes the occupations (analyst, programmer, and operator) and departments that emerged around them. This illuminates claims of a more recent electronic revolution in business.
Effects of mutual coupling in a high fidelity, circularly polarized, probe-fed, two-element pentagonal patch array

The paper examines spatial and frequency variations of mutual coupling on the axial ratio in a two-element, circularly polarized, probe-fed array of pentagonal patches designed on infinite-grounded dielectric (/spl epsiv//sub r/=2.2 and 4.5) substrates having a 0.4 dB axial ratio at 2.24 GHz. The results for changes in the 3 dB axial ratio bandwidth with increase in substrate permittivity are emphasized and are included along with results quantifying the effects of increased spatial variations on the same parameter.
RETINAL PROCESSING NEAR ABSOLUTE THRESHOLD: From Behavior to Mechanism

Vision at absolute threshold is based on signals produced in a tiny fraction of the rod photoreceptors. This requires that the rods signal the absorption of single photons, and that the resulting signals are transmitted across the retina and encoded in the activity sent from the retina to the brain. Behavioral and ganglion cell sensitivity has often been interpreted to indicate that these biophysical events occur noiselessly, i.e., that vision reaches limits to sensitivity imposed by the division of light into discrete photons and occasional photon-like noise events generated in the rod photoreceptors. We argue that this interpretation is not unique and provide a more conservative view of the constraints behavior and ganglion cell experiments impose on phototransduction and retinal processing. We summarize what is known about how these constraints are met and identify some of the outstanding open issues.
EFFECT OF TEMPERATURE OF ALDEHYDE FIXATION ON THE RADIOAUTOGRAPHIC LOCALIZATION OF RIBONUCLEOPROTEIN IN NUCLEOLI OF HELA CELLS : Inhibition by Puromycin and Actinomycin D

In efforts to clarify the role of the nucleolus and substructures thereof in the assembly or synthesis of protein associated with formation of the complete ribosome, the effect of variation of some conditions of aldehyde fixation on the intranuclear distribution of lysine-3H, arginine-3H, and uridine-3H was studied by differential grain count in radioautographs of PPLO-free HeLa cells. It was found that the nucleolus is a site of rapid assembly or synthesis of a protein, the synthesis of which is inhibited equally by puromycin (200 µg/ml) and by actinomycin D under conditions inhibitory for ribosomal precursor RNA synthesis (P < 0.01). This protein is fixed by phosphate-buffered formalin or glutaraldehyde at pH 7.3, but the label is diminished by fixation in customarily employed acetic ethanol or in formalin at acid pH. Elevation of temperature of formalin or glutaraldehyde fixatives to 37°C consistently reduces the nucleolar protein label, but not the RNA label, by a proportion identical with that incurred by puromycin or actinomycin inhibition. This proportional reduction of nucleolar protein label occurs without evident loss of total grain count and is independent of length of fixation between 30 min and 4 hr, but it is not observed at 23°C. The data support the interpretation that the proportion of nucleolar protein not fixed at 37°C is associated with nucleolar ribosomal RNA but that it is dissociated at 37°C in formalin or glutaraldehyde fixatives, probably on the basis of ionic dissociation of a conjugated ribonucleoprotein.
Nutrient cycling in lakes and streams: insights from a comparative analysis.

Understanding of general ecosystem principles may be improved by comparing disparate ecosystems. We compared nutrient cycling in lakes and streams to evaluate whether contrasts in hydrologic properties lead to different controls and different rates of internal nutrient cycling. Our primary focus was nutrient cycling that results in increased productivity, so we quantified nutrient cycling by defining the recycling ratio (ρ) as the number of times a nutrient molecule is sequestered by producers before export. An analytic model of nutrient cycling predicted that in lakes ρ is governed by the processes that promote the mineralization and retard the sedimentation of particulate-bound nutrients, whereas in streams, ρ is governed by processes that promote the uptake and retard the export of dissolved nutrients. These differences were the consequence of contrast between lakes and streams in the mass-specific export rates (mass exported · standing stock-1· time-1) of dissolved and particulate nutrients. Although ρ is calculated from readily measured ecosystem variables, we found very few published data sets that provided the necessary data for a given ecosystem. We calculated and compared ρ in two well-studied P-limited ecosystems, Peter Lake and West Fork Walker Branch (WFWB). When ecosystems were scaled so that water residence time was equal between these two ecosystems, ρ was three orders of magnitude greater in WFWB. However, when we scaled by P residence time, ρ was nearly equal between these two ecosystems. This suggests broad similarities in ρ across ecosystem types when ecosystem boundaries are defined so that turnover times of limiting nutrients are the same.
A rehabilitation of the genetic map of the 84B-D region in Drosophila melanogaster.

A reanalysis of the 84B3 to 84D3,5 region of the polytene chromosomes of Drosophila melanogaster has led to the identification and localization of 16 genes. These genes include 11 vital loci, four genes exhibiting nonlethal visible mutant phenotypes and one gene encoding a nonessential enzyme. The identity of the gene products of two of the vital genes has been determined to be a-tubulin and glucose dehydrogenase (Gld). Three newly identified genes, sticking (stk), halfout (hat) and trapped (ted), as well as Gld are required for eclosion. Among the nonessential genes are roughened eye (roe) and ruffed eye (rue), which affect eye texture. The roe phenotype is greatly enhanced by deletions that simultaneously remove roe and an unidentified locus in 84E. Mutations in another nonessential gene, rotund (rn), are characterized by pattern deletions of most adult appendages. HE 84B-E region of the right arm of the third chromosome of D. melanT ogaster has received considerable attention during the past few years due to the presence of the Antennapedia complex (ANT-C) (KAUFMAN and ABBOTT 1984), two a-tubulin genes (RAFF 1984), the glucose dehydrogenase gene (CAVENER and MACINTYRE 1983) and doublesex (dsx) (DUNCAN and KAUFMAN 1975; BAKER and RIDGE 1980). A complementation analysis of this region was previously reported on by LEWIS et al. (1980). A revision of this analysis was necessitated by a number of new lesions recovered in this region and by some unfortunate errors in the initial analysis. We present here a revised complementation analysis of the region between the distal extent of the ANT-C
Hyperforin, the Active Component of St. John's Wort, Induces IL-8 Expression in Human Intestinal Epithelial Cells Via a MAPK-Dependent, NF-κB-Independent Pathway

St. John’s wort is widely used as an herbal antidepressant and is among the top-selling botanical products in the United States. Although St. John’s wort has been reported to have minimal side effects compared with other antidepressants, here we show that hyperforin, the active component of St. John’s wort, can stimulate interleukin-8 (IL-8) expression in human intestinal epithelia cells (IEC) and primary hepatocytes. Hyperforin is also able to induce expression of mRNA, encoding another major inflammatory mediator—intercellular adhesion molecule-1 (ICAM-1). IEC participate in the intestinal inflammatory process and serve as a first line of defense through bidirectional communication between host and infectious pathogens. Although hyperforin is a potent ligand for the steroid and xenobiotic receptor (SXR), we found that hyperforin induced IL-8 mRNA through an SXR-independent transcriptional activation pathway. IL-8 induction by hyperforin required the activation of AP-1 but not the NF-κB transcription factor, thereby distinguishing it from the NF-κB-dependent IL-8 induction mediated by tumor necrosis factor α (TNFα). Further study revealed that extracellular signal-regulated kinase 1 and 2 (ERK1/2) were required for the hyperforin-induced expression of IL-8. Our results suggest a previously unsuspected effect of St. John’s wort in modulating the immune and inflammatory responses.
In vitro evaluation of three intravenous fluid line warmers

Objective—To determine in vitro output temperature differences of 3 IV fluid warmers. Design—Prospective, randomized study. Sample—3 IV fluid warmers. Procedures—Warming capabilities of a distance-dependent blood and fluid warmer marketed for human and veterinary use (product A) and a veterinary-specific distance-dependent fluid warmer (product B) were compared at 0, 4, 8, and 12 cm from the device to the test vein and at flow rates of 20, 60, 100, 140, 180, 220, 260, and 300 mL/h with room temperature (approx 22°C) fluids (phase 1). The superior warming device was compared against a distance-independent IV fluid warmer (product C) with room temperature fluids at the same flow rates (phase 2). The effect of prewarmed fluids (38°C) versus room temperature fluids was evaluated with the superior warming device from phase 2 (phase 3). Results—In phase 1, product B produced significantly warmer fluids than product A for all flow rates and distances. Both distance-dependent devices produced warmer fluid at 0 cm...
Sakurai’s Object, V605 Aquilae, and FG Sagittae: An Evolutionary Sequence Revealed

We have completed a grid of stellar evolution calculations to study the behavior of the born-again phenom- enon. All our evolutionary sequences begin with a uniform composition 1 Mstar on the pre-main-sequence Hayashi phase and end on the white dwarf cooling track. The effects of combined helium and hydrogen burn- ing and time-dependent convective mixing are included. We artificially vary the mass-loss rate beginning at the peak of the last thermal pulse on the asymptotic giant branch in order to create a range of He-layer masses for the post-asymptotic giant branch (AGB) evolution. We find that a very late thermal pulse occurs in 10%- 15% of cases. Our models supply an answer to the question of why the born-again stars V4334 Sgr (Sakurai's object) and V605 Aql have a significantly shorter evolutionary timescale than the otherwise similar born- again star FG Sge. FG Sge has been observed to undergo born-again behavior for more than 120 yr, while the other two objects have evolved in a similar way but in less then 10 yr. Models with low convective mixing efficiency, � 10 � 4 , first evolve quickly to the AGB, return to the blue, and then evolve more slowly back to the AGB for a second time before finally returning to the white dwarf cooling track. The difference in evolution timescales can then be explained by proposing that Sakurai's object is evolving to the AGB for the first time but that FG Sge has been observed during its second return to the AGB. Our models allow us to make some testable predictions: (1) Sakurai's object will increase in effective temperature in the next 20-50 yr and will then resemble V605 Aql's present high effective temperature state; (2) V605 Aql will cool back toward the AGB some time in the next 50-70 yr, at which point it will evolve in the same way as has been observed for FG Sge over the last 120 yr; and (3) FG Sge will show signs of increasing its effective temperature by about 1500-2000 K in as soon as 10-20 yr, depending on the metallicity of its progenitor main-sequence star. Subject headings: stars: AGB and post-AGB — stars: evolution — stars: individual (Sakurai's object, V605 Aquilae, FG Sagittae) — stars: variables: other
Miniaturizing the spherical sundial: A hemispherical sensor for orientation and positioning with respect to point sources of light

We propose a novel solar sensor geometry utilizing a hemispherical arrangement of pixels to determine the vector to the dominant light source in its environment. We show two methods for calculating this vector: one based on transforming the problem from an optical one into a geometric one, and another using a least squares approach to minimize the error function for the sensor. These methods do not depend on the physical details of any particular sensor design. Both methods rely upon certain assumptions, but methods for extracting an accurate sun vector are discussed which do not rely upon such an idealized environment. Using the estimate of the sun vector, it is possible to determine the location of the sensor on the Earth. Applications include position measurement and navigation for UAVs, UGVs, and other mobile platforms.
Incredibly late thromboses in first generation drug eluting stents: a case series

The drug-eluting stents have decreased the incidence of instent restenosis compared to bare metal stents. But, the incidence of late and very late stent thrombosis has increased with the drug-eluting stents. We are here, reporting three cases of incredibly late instent thrombosis, each one occurring after more than 50 months of drug-eluting stent placement. The occurrence of stent thrombosis as late as 5 years has been reported in literature. This highlights the importance that there may be no limit to the time duration to the occurrence of very late stent thrombosis and dual antiplatelet therapy with aspirin and clopidogrel may have to be continued indefinitely in patients with drug-eluting stents.
Monitoring papilledema with Heidelberg Retina Tomograph in a patient with ruptured aneurysm: a case report

Abstract Background Heidelberg Retina Tomograph is a scanning laser ophthalmoscope that is routinely used for the assessment and serial measurement of optic nerve morphology and nerve fiber layer anatomy in the setting of elevated intraocular pressure typically encountered in glaucoma. Recent studies have explored the use of this device in the objective assessment of optic nerve head swelling occurring in the setting of elevated intracranial pressure, also known as papilledema. We explore the utility of HRT as a complementary evaluation to serial fundoscopic examination of the optic nerve head in a patient with a high-grade SAH, raised intracranial pressure, and papilledema secondary to rupture of a giant intracranial aneurysm. To our knowledge, this represents the first report of the use of this technology as an objective assessment of papilledema in the setting of SAH. Case Description A 23-year-old man presented with spontaneous SAH secondary to a ruptured giant internal carotid artery aneurysm. The patient underwent endovascular embolization to prevent further hemorrhage and was monitored with HRT on a monthly basis. Severe papilledema, present at the outset and confirmed by the neuro-ophthalmologic consultant, was followed by serial examination with the device. Conclusion Heidelberg Retina Tomograph is a promising device for the analysis of optic nerve head topography in the setting of papilledema in SAH. Worsening or resolution of papilledema can be qualitatively demonstrated with serial studies using this device.
Development and environmental application of a nitrate selective microsensor based on doped polypyrrole films

This work describes the development and testing of a sensitive and selective potentiometric nitrate microsensor based on doped polypyrrole films. Utilizing 6-7 m carbon fibers as a substrate for pyrrole electropolymerization allowed fabrication of flexible, miniature and inexpensive sensors for in situ monitoring of nitrate. The sensors have a rapid response (several seconds) and in their characteristics are competitive with expensive commercial nitrate ion selective electrodes (ISE), exhibiting Nernstian behavior (slopes 54 ± 1 mV per log cycle of nitrate concentration (n = 8), at T =2 2 ◦ C), a linear response to nitrate concentrations spanning three orders of magnitude (0.1-10 −4 M or 6200-6.2 ppm of NO3 − ), and a detection limit of (3 ± 1) × 10 −5 M (1.25-2.5 ppm). After a 2-month-period, the response was unchanged, and after 4.5 months, one version of the electrode continued to exhibit significant sensitivity to nitrate. Several polypyrrole nitrate microsensors were embedded sequentially downstream from a point source of nitrate solution in an intermediate scale physical groundwater model as a test of their performance under simulated environmental conditions. The microsensors responded appropriately to the approaching nitrate solution front, demonstrating dispersion and attenuation of the nitrate concentrations that increased with distance from the source. © 2004 Elsevier B.V. All rights reserved.
Visual programming: limits of graphic representation

The effectiveness of graphic representations of computer programs is analyzed. Existing software metrics are modified for use in analyzing diagrams, and two new metrics are proposed: graphic token count and diagram class complexity. A graphic design measure, data density, is transformed into a computer science measure, token density. Using these metrics, graphic representations can be compared to each other and to textual representations. Conclusions are drawn about the relative strengths of graphic and textual representation. >
Homogenization Theory for the Prediction of Obstructed Solute Diffusivity in Macromolecular Solutions

The study of diffusion in macromolecular solutions is important in many biomedical applications such as separations, drug delivery, and cell encapsulation, and key for many biological processes such as protein assembly and interstitial transport. Not surprisingly, multiple models for the a-priori prediction of diffusion in macromolecular environments have been proposed. However, most models include parameters that are not readily measurable, are specific to the polymer-solute-solvent system, or are fitted and do not have a physical meaning. Here, for the first time, we develop a homogenization theory framework for the prediction of effective solute diffusivity in macromolecular environments based on physical parameters that are easily measurable and not specific to the macromolecule-solute-solvent system. Homogenization theory is useful for situations where knowledge of fine-scale parameters is used to predict bulk system behavior. As a first approximation, we focus on a model where the solute is subjected to obstructed diffusion via stationary spherical obstacles. We find that the homogenization theory results agree well with computationally more expensive Monte Carlo simulations. Moreover, the homogenization theory agrees with effective diffusivities of a solute in dilute and semi-dilute polymer solutions measured using fluorescence correlation spectroscopy. Lastly, we provide a mathematical formula for the effective diffusivity in terms of a non-dimensional and easily measurable geometric system parameter.
Entanglement negativity after a local quantum quench in conformal field theories

We study the time evolution of the entanglement negativity after a local quantum quench in (1 + 1)-dimensional conformal field theories (CFTs), which we introduce by suddenly joining two initially decoupled CFTs at their end points. We calculate the negativity evolution for both adjacent intervals and disjoint intervals explicitly. For two adjacent intervals, the entanglement negativity grows logarithmically in time right after the quench. After developing a plateau-like feature, the entanglement negativity drops to the ground-state value. For the case of two spatially separated intervals, a light-cone behavior is observed in the negativity evolution; in addition, a long-range entanglement, which is independent of the distance between two intervals, can be created. Our results agree with the heuristic picture that quasiparticles, which carry entanglement, are emitted from the joining point and propagate freely through the system. Our analytical results are confirmed by numerical calculations based on a critical harmonic chain.