cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of an intense prescribed fire on understory vegetation in a mixed conifer forest1

Abstract Huisinga, K. D., D. C. Laughlin, P. Z. Fule, J. D. Springer, and C. M. McGlone (Ecological Restoration Institute and School of Forestry, Northern Arizona University, Box 15017, Flagstaff, AZ 86011). Effects of an intense prescribed fire on understory vegetation in a mixed conifer forest. J. Torrey Bot. Soc. 132: 590–601. 2005.—Intense prescribed fire has been suggested as a possible method for forest restoration in mixed conifer forests. In 1993, a prescribed fire in a dense, never-harvested forest on the North Rim of Grand Canyon National Park escaped prescription and burned with greater intensity and severity than expected. We sampled this burned area and an adjacent unburned area to assess fire effects on understory species composition, diversity, and plant cover. The unburned area was sampled in 1998 and the burned area in 1999; 25% of the plots were resampled in 2001 to ensure that differences between sites were consistent and persistent, and not due to inter-annual climatic differences. Spe...
Using ungulate occurrence to evaluate community-based conservation within a biosphere reserve model

Conservation areas in tropical forests protect the most diverse and threatened ecosystems on the planet. In the Amazon, ungulates are important determinants of forest structure and plant diversity, as well as being a resource for rural communities. Using occupancy-based methods, we estimated the occurrence of white-lipped peccary Tayassu pecari, collared peccary Pecari tajacu, lowland tapir Tapirus terrestris and red brocket deer Mazama americana in and around protected areas reserve in Tambopata, Peru, to evaluate how different management designation, anthropogenic influences and habitat type influenced the occurrence of each species. We used a combination of track surveys (n=258) and camera surveys (n=256) to estimate ungulate presence at 55 sites in a national reserve, a native community and adjacent buffer areas from May 2008 to March 2009. We found that prediction of the occurrence of white-lipped peccary, lowland tapir and red brocket deer was best accomplished using travel time from the nearest city (a measure of an area's accessibility). The occurrence of ungulates differed little between buffer and reserves, but community lands managed by indigenous peoples showed reduced probabilities of ungulate occurrence. Our results indicate that passive protection afforded by inaccessibility might be an effective management strategy for this region; however, we doubt that this is tenable as a long-term solution.
Identification and Characterization of a Leucine-Rich Repeat Kinase 2 (LRRK2) Consensus Phosphorylation Motif

Mutations in LRRK2 (leucine-rich repeat kinase 2) have been identified as major genetic determinants of Parkinson's disease (PD). The most prevalent mutation, G2019S, increases LRRK2's kinase activity, therefore understanding the sites and substrates that LRRK2 phosphorylates is critical to understanding its role in disease aetiology. Since the physiological substrates of this kinase are unknown, we set out to reveal potential targets of LRRK2 G2019S by identifying its favored phosphorylation motif. A non-biased screen of an oriented peptide library elucidated F/Y-x-T-x-R/K as the core dependent substrate sequence. Bioinformatic analysis of the consensus phosphorylation motif identified several novel candidate substrates that potentially function in neuronal pathophysiology. Peptides corresponding to the most PD relevant proteins were efficiently phosphorylated by LRRK2 in vitro. Interestingly, the phosphomotif was also identified within LRRK2 itself. Autophosphorylation was detected by mass spectrometry and biochemical means at the only F-x-T-x-R site (Thr 1410) within LRRK2. The relevance of this site was assessed by measuring effects of mutations on autophosphorylation, kinase activity, GTP binding, GTP hydrolysis, and LRRK2 multimerization. These studies indicate that modification of Thr1410 subtly regulates GTP hydrolysis by LRRK2, but with minimal effects on other parameters measured. Together the identification of LRRK2's phosphorylation consensus motif, and the functional consequences of its phosphorylation, provide insights into downstream LRRK2-signaling pathways.
A Major Epigenetic Programming Mechanism Guided by piRNAs

A central enigma in epigenetics is how epigenetic factors are guided to specific genomic sites for their function. Previously, we reported that a Piwi-piRNA complex associates with the piRNA-complementary site in the Drosophila genome and regulates its epigenetic state. Here, we report that Piwi-piRNA complexes bind to numerous piRNA-complementary sequences throughout the genome, implicating piRNAs as a major mechanism that guides Piwi and Piwi-associated epigenetic factors to program the genome. To test this hypothesis, we demonstrate that inserting piRNA-complementary sequences to an ectopic site leads to Piwi, HP1a, and Su(var)3-9 recruitment to the site as well as H3K9me2/3 enrichment and reduced RNA polymerase II association, indicating that piRNA is both necessary and sufficient to recruit Piwi and epigenetic factors to specific genomic sites. Piwi deficiency drastically changed the epigenetic landscape and polymerase II profile throughout the genome, revealing the Piwi-piRNA mechanism as a major epigenetic programming mechanism in Drosophila.
Erythrocyte and erythropoietin responses to hemorrhage in the immature and near term ovine fetus.

Abstract Objective: Previous reports suggested that immature ovine fetuses have a greater erythropoietin response to hemorrhage than those near term. This study tested the hypothesis that immature ovine fetuses would expand their red cell mass more rapidly than near term fetuses after hemorrhage. Study Design: Chronically catheterized immature ovine fetuses at 109.5 ± 0.3 (mean ± SE) days' gestation (term = 150 days) were studied over a 10-day period. They either underwent hemorrhage of 40% of their measured blood volume on day 3 or were in a time control group monitored without hemorrhage. Red cell mass, hematocrit, blood volume, plasma volume, and plasma erythropoietin concentrations were measured at 24- and 48-hour intervals. Responses in the immature fetuses were compared with responses in near term fetuses. Results: In the control group red cell mass, hematocrit, blood, and plasma volumes increased significantly, whereas plasma erythropoietin concentration decreased significantly with advancing gestational age. In immature fetuses that underwent hemorrhage, the relative changes in red cell mass, hematocrit, and plasma erythropoietin concentration were not significantly different from those seen in the near term fetuses. The only significant posthemorrhage difference was that the increases in blood and plasma volumes were greater in the immature compared with the near term fetuses. Conclusion: Immature and mature fetuses have similar erythrocyte and erythropoietin responses to moderately severe hemorrhage. The larger blood and plasma volume responses in the immature fetuses are consistent with the concept that they have a greater extracellular fluid volume. (Am J Obstet Gynecol 2001;185:501-6.)
Identity Exploration, Commitment, and Existential Anxiety as Predictors of the Forms and Functions of Aggression

This study explores the unique linkages among identity exploration, identity commitment, existential anxiety, and the different forms (relational and overt) and functions (proactive and reactive) of peer aggression in youth. Participants were high school students (N = 133) aged 15 to 19 years. In terms of zero-order associations, existential anxiety was positively associated with each of the four types of aggression whereas identity exploration and identity commitment were only associated (negatively) with proactive overt aggression. However, in terms of unique associations, identity exploration was negatively associated with proactive aggression (overt and relational) whereas existential anxiety was positively associated with all but proactive relational aggression. Identity commitment was not uniquely associated with any of the forms and functions of aggression. Findings are discussed in terms of consistency with theory as well as unique and possible suppressor relationships. Avenues for additional rese...
Penetrance and expressivity in the molecular age

Penetrance and expressivity have been defined through clinical experience. Although penetrance is often seen as the end of the spectrum of expressivity, penetrance and expressivity are considered as distinct phenomena. A review of the known mechanisms underlying either penetrance or expressivity reveals that in most of the cases the same explanation is true for both phenomena. Some of the known mechanisms include modifier genes, the influence of the allele in trans, sex, and environmental factors. Although rapid progress has been made in understanding of the basis of incomplete penetrance and the differences of expressivity, they still remain unknown for most of the genetic disorders. In recent years, it has become evident that there is much in common between the classical Mendelian traits in which the inheritance has been seen as "simple" and most of the common diseases in which the inheritance is "complex." In both cases genetic and/or environmental factors are acting in a complex way.
Human Productivity of Space Station

The objectives of NASA's Space Station Human Productivity Program are examined. The design and functions of the Space Station are described. The effects of the interior architecture, crew support, crew activities, intravehicular activity (IVA) systems, and extravehicular/IVA interfaces on the productivity of the Space Station are investigated. It is estimated that crew productivity should be sustained for a 90-day tour at levels above 90 percent of the initial mission performance level.
Laboratory experiments on the electrodynamic behavior of tethers in space

The transient current systems between tethered plasmas in a large magnetoplasma are investigated experimentally for extrapolation to electrodynamic tethers in space. The studies measure the perturbed magnetic fields and the current density associated with pulsed currents to electrodes in three-dimensional space and time. The electrodes excite electron whistlers because they produce fields that dominantly couple to electrons, allowing pulsed currents to propagate and disperse as whistler wave packets. The wave packets evolve into force-free, flux-ropelike field configurations, and a whistler 'wedge' is formed in the plasma due to 'eddy' currents caused by insulated tethers with dc currents. Substantial radiation into the whistler mode happens with moving VLF antennas as well as tethers, and the wave spread within the ray cone is the most significant characteristic event. The wave spread widens the current channel, incites current closure, and is also associated with a 'phantom loop' phenomenon.
Numerical Investigation of Oxide Layer Growth of Stainless Steel LBE at a Mesoscopic Level

The corrosiveness of LBE, as an ideal coolant candidate in reactors and accelerator driven systems (ADS), presents a critical challenge for safe applications. One of the effective ways to protect the materials is to form and maintain a protective oxide film along the structural material surfaces by active oxygen control technology. The oxidation process of metals in lead bismuth eutectic (LBE) environment is investigated numerically at a mesoscopic scale. An improved stochastic cellular automaton model based on an improved Moore neighborhood is proposed to investigate the development of a continuous oxide layer of metals in LBE. The ionization of metal and the oxidation reaction were simulated with consideration of the transport of oxygen along the grain boundary and the diffusion of metallic ions. The model was benchmarked with a pure diffusion process, both with the analytical solution and with the previous work. Significant agreement was reached between the data. The developed model is also mapped with the experimental data from an LBE loop. A parametric study was conducted in order to check the importance of the main explicit parameters of the mesoscopic model. The boundary condition at the far end of the specimen has been investigated for the CA model.© 2008 ASME
AAV-Dominant Negative Tumor Necrosis Factor (DN-TNF) Gene Transfer to the Striatum Does Not Rescue Medium Spiny Neurons in the YAC128 Mouse Model of Huntington's Disease

CNS inflammation is a hallmark of neurodegenerative disease, and recent studies suggest that the inflammatory response may contribute to neuronal demise. In particular, increased tumor necrosis factor (TNF) signaling is implicated in the pathology of both Parkinson's disease (PD) and Alzheimer's disease (AD). We have previously shown that localized gene delivery of dominant negative TNF to the degenerating brain region can limit pathology in animal models of PD and AD. TNF is upregulated in Huntington's disease (HD), like in PD and AD, but it is unknown whether TNF signaling contributes to neuronal degeneration in HD. We used in vivo gene delivery to test whether selective reduction of soluble TNF signaling could attenuate medium spiny neuron (MSN) degeneration in the YAC128 transgenic (TG) mouse model of Huntington's disease (HD). AAV vectors encoding cDNA for dominant-negative tumor necrosis factor (DN-TNF) or GFP (control) were injected into the striatum of young adult wild type WT and YAC128 TG mice and achieved 30–50% target coverage. Expression of dominant negative TNF protein was confirmed immunohistologically and biochemically and was maintained as mice aged to one year, but declined significantly over time. However, the extent of striatal DN-TNF gene transfer achieved in our studies was not sufficient to achieve robust effects on neuroinflammation, rescue degenerating MSNs or improve motor function in treated mice. Our findings suggest that alternative drug delivery strategies should be explored to determine whether greater target coverage by DN-TNF protein might afford some level of neuroprotection against HD-like pathology and/or that soluble TNF signaling may not be the primary driver of striatal neuroinflammation and MSN loss in YAC128 TG mice.
Chronosequence development and soil variability from a variety of sub-alpine, post-glacial landforms and deposits in the southeastern San Juan Mountains of Colorado

Abstract Surficial processes acting on post-glacial alpine and sub-alpine landscapes vary at small temporal and spatial scales and are thus often difficult to conceptualize in the context of large-scale landscape evolution models. Soils developing in this setting can thus provide valuable information about landform genesis, sedimentology and age. Relatively few post-glacial chronosequences have been examined in these settings however, particularly for the variety of landforms and parent materials that exist within alpine and sub-alpine environments. Here, we examine a chronosequence of relatively young, post-glacial landforms with varying parent materials and climate histories. We dug and described 39 soil pits in the upper Conejos River Valley of Colorado on a variety of deposits and landforms, including alluvial fans, terraces, colluvium, glacial till, and terminal moraines, and compared soil properties with radiocarbon ages from the area. Our results suggest that some typical chronosequence soil properties (e.g., pH, structure, color) do not correlate with time over short time scales. However, extractable iron ratios (Feo/Fed) show a relatively strong correlation with age across late-Pleistocene and Holocene time scales and maximum profile clay content shows a weak but statistically significant relationship with age. Both of these trends are stronger when examined across a single parent material. Differences in initial parent material texture and dust inputs seem to be the most significant complicating factors over post-glacial time scales. Soil property development through time is most inconsistent in cumulic alluvial fan soils. This observation may indicate that alluvial fans are more responsive to sub-basin scale processes as opposed to fluvial terraces that are more likely respond to processes active across the entire basin. These differences would explain why stratigraphically similar alluvial fans are mantled by soils with varying development. Nonetheless, horizonation, clay content, and extractable iron ratios provide a useful tool for correlating young deposits, assigning ages, and interpreting the geomorphic history of complex post-glacial environments.
Gross rents and market values: Testing the implications of Tiebout's hypothesis

Abstract In this paper, we propose a new empirical test of the implications of the Tiebout hypothesis. The test we advance uses gross rent rather than market value as the dependent variable in the estimating equation; we argue that this improves upon the previous studies in several respects. We then explore the determinants of gross rent using a large sample of single-family dwellings in San Mateo County, California.
Dosimetry study of split beam technique using megavoltage beams and its clinical implications—I megavoltage beams and its clinical implications—I

Abstract The problem of beam divergence and overlapping of adjacent fields in the treatment planning is well known. The use of “split beam” technique has been suggested as one way of addressing this problem. The present work reports a detailed dosimetry of this technique 60 Co beam (Theratron 780). The dose distributions at and near the junction plane between two adjacent fields were measured; they were compared with those for diverging fields (with and without gap on the skin). As an illustration, different treatment planning techniques for head and neck tumors and subsequent dose distributions are discussed. Our findings clearly indicate that the extension of penumbra near the geometrical edge of a split beam is considerably less than that of an open beam of the same field size. Consequently when two adjacent fields are used, the overdose at and near the junction plane is reduced greatly by the split beam. For head and neck tumors the split beam technique gives a much better dose distribution than any other conventional treatment techniques.
Deletion of RBM and DAZ in azoospermia: evaluation by PRINS.

Molecular and cytogenetic studies from infertile men have shown that one or more genes controlling spermatogenesis are located in proximal Yq11.2 in interval 6 of the Y chromosome. Microdeletions within the azoospermia factor region (AZF) are often associated with azoospermia and severe oligospermia in men with idiopathic infertility. We evaluated cells from a normal-appearing 27-year-old man with infertility and initial karyotype of 45,der(X)t(X;Y) (p22.3;p11.2)[8]/46,t(X;Y)(p22.3;p11.2)[12]. By fluorescence in situ hybridization with dual-color whole chromosome paint probes for X and Y chromosomes, we confirmed the Xp-Yp interchange. By primed in situ labeling, we identified translocation of the SRY gene from its original location on Yp to the patient's X chromosome at band Xp22. We also obtained evidence that the apparent marker was a der(Y) (possibly a ring) containing X and Y domains, and observed that the patient's genome was deleted for RBM and DAZ, two candidate genes for AZF.
Use of Portable Antennas to Estimate Abundance of PIT-Tagged Fish in Small Streams: Factors Affecting Detection Probability

Abstract Portable passive integrated transponder (PIT) tag antenna systems can be valuable in providing reliable estimates of the abundance of tagged Atlantic salmon Salmo salar in small streams under a wide range of conditions. We developed and employed PIT tag antenna wand techniques in two controlled experiments and an additional case study to examine the factors that influenced our ability to estimate population size. We used Pollock's robust-design capture–mark–recapture model to obtain estimates of the probability of first detection (p), the probability of redetection (c), and abundance (N) in the two controlled experiments. First, we conducted an experiment in which tags were hidden in fixed locations. Although p and c varied among the three observers and among the three passes that each observer conducted, the estimates of N were identical to the true values and did not vary among observers. In the second experiment using free-swimming tagged fish, p and c varied among passes and time of day. Addi...
The mechanism of transfection enhancement by bentonite.

Bentonite was found to enhance markedly the transfection, by poliovirus RNA, of sheet cultures of primate cells. The enhancement was greater for calciumdepleted cells than for nondepleted cells, and greater for the eta line of monkey kidney cells than for KB cells. The enhancement occurred only when the concentration of the buffered salt solution used was within a region rather sharply delimited at both ends, and only when the bentonite was mixed with the RNA inoculum.
The Steady-State Operational Calculus

The direct and inverse transforms of the steady-state operational calculus are presented, together with two methods of evaluating the inverse transform, the first resulting in a Fourier series and the second giving a sum function. A proof of the inversion theorem connecting the two transforms is outlined in the Appendix. Two examples are presented illustrating the application of this operational calculus to circuit problems, and a comparison is made between the ordinary and the steady-state operational calculuses.
A triangular plate finite element for large-displacement elastic-plastic analysis of automobile structural components

Abstract This paper presents a simple, nonlinear triangular plate finite element developed for analyzing elastic-plastic, large-displacement behavior of shell type automobile structural components. The element is derived from Lagrange's strain-displacement relations. By being a plate element, the interpolation functions for the in-plane and the out-of-plane displacements are uncoupled. The element employs linear functions for the in-plane displacements and a quadratic function for the out-of-plane displacement. The material of the element is assumed to follow the von Mises yield criterion and the Prandtl-Reuss flow rule. The incremental stiffness matrices are obtained from the principle of virtual work. Four examples are furnished to demonstrate the versatility and accuracy of the presented simple plate element in modeling structures of automobile applications.
Long-term soil potassium availability from a Kanhapludult to an aggrading loblolly pine ecosystem

Abstract A long-term (1962 to 1990) forest biogeochemistry study in the southeastern Piedmont of the USA provided estimates of soil K release in response to forest regrowth. We investigated the sources of soil K that buffered the exchangeable K pools during forest growth and we estimated soil K release rates through greenhouse and acid extraction studies for comparison to our field estimate. In these acid Kanhapludults, derived from granitic-gneiss, the disparity between measured depletions of soil exchangeable K and estimated forest removals indicated a buffering of exchangeable K on the order of 0.31 kmolc ha−1 per year. Non-exchangeable K extracted by boiling with 1 M HNO3 exceeded exchangeable K by up to 40-fold. Non-exchangeable K was not depleted during the three decades of stand growth, however, thus was not the long-term source of exchangeable K buffering. Total K in these soils ranged from 0.4 to 3.8% by weight. Mineralogical data indicated a presence of hydroxy-interlayered vermiculite throughout the upper 4 m of soil for Estimated K releases in the greenhouse and extraction studies were generally consistent with long-term results. The accumulation of K during two rotations of pine seedling growth in the greenhouse exceeded the measured depletions in exchangeable and non-exchangeable K over all soil depths tested by 0.007 to 0.026 cmolc kg−1. Potassium removal by sequential extraction/incubations with 1 mM HCl and 1 mM oxalic acid continued through 24 extractions and K recovered in extract solutions exceeded the sum of depletions in exchangeable and non-exchangeable K pools by 0.001 to 0.028 cmolc kg−1. These excess removals in plant uptake or solution recovery indicate a release of mineral K. Thirty-day extractions with H+-resins in both 1 mM HCl and 1 mM oxalic acid were well fit by the Elovich equation but were not well correlated with plant K uptake in the greenhouse study. The release rate coefficients ranged from 0.012 to 0.025(cmolc kg−1) h−1. Extrapolations to annual releases of K in the greenhouse and sequential extraction studies were a similar order of magnitude as long-term releases estimated at the long-term Calhoun plots. Surface soil (0 to 15 cm) releases ranged from 0.15 to 0.65 kmolc ha−1per year while deeper soils ranged up to 1.54 kmolc ha−1per year. Results indicate that soils similar to those at Calhoun that contain a similar micaceous and HIV component will be able to supply K at rates adequate to keep pace with demands of forest regrowth even under intensive forest management.
3,6a-Dihydroxy-8,9-methylenedioxypterocarpan as a metabolite of pisatin produced by Fusarium solani f. sp. pisi

Abstract One of the fungal metabolites of pisatin has been identified as resulting from the demethylation of pisatin at position 3.
Stimulation of rat liver cyclic 3':5'-nucleotide phosphodiesterase by cyclic GMP is dependent on enzyme concentration.

Abstract A high-speed supernatant of rat liver extract displayed multiple forms of cyclic nucleotide phosphodiesterase (EC 3.1.4.17). One of the forms catalyzed the hydrolysis of cyclic AMP and cyclic GMP, with approximately comparable facility. One salient feature of the enzyme is that at micromolar concentrations, cyclic GMP stimulated the hydrolysis of cyclic AMP, but not vice versa. Another is that the activity of phosphodiesterase varied as a function of enzyme concentration in the assayed system: the enzyme activity was higher at low than at high enzyme concentrations. A concentrated enzyme was not stimulated by cyclic GMP but was stimulated by cyclic GMP upon dilution of the enzyme. Conversely, stimulation of the enzyme by cyclic GMP could be reversed by increasing the enzyme concentration. The cyclic GMP-stimulated cyclic AMP phosphodiesterase was partially purified by a continuous sucrose density gradient. The apparent change of phosphodiesterase activity as a function of enzyme concentration was also observed after partial purification by the sucrose density gradient. High enzyme concentrations favored the aggregated form of phosphodiesterase, whereas low concentrations favored the dissociated form. Dilution of the enzyme shifted the equilibrium toward the dissociated form, which presumably exposed the cyclic GMP regulatory site on the enzyme molecule.
Thyroglobulin structure-function: Anilinonaphthalene sulfonate binding and the definition of nonpolar sites on native bovine thyroglobulin

Summary Native bovine thyroglobulin has been shown by fluorescence titration and equilibrium dialysis to bind 6 moles of 1,8 anilinonaphthalene sulfonate (ANS) per mole of protein at pH 7.0 in 0.1 M sodium phosphate buffer. The average dissociation constant for this binding is 3 × 10 −5 M. Analysis of the binding data indicates significant cooperativity in the interaction with the reaction order, J, near 2. The binding of ANS to bovine thyroglobulin is accompanied by a blue shift in the ANS fluorescence maximum of near 50 nm and an increase in fluorescence yield of approximately 60 fold.
Vasculitis look-alikes and pseudovasculitis syndromes

Vasculitis is true inflammatory disease of the blood vessels. It may be generalized (systemic) or localized (isolated); and it may arise de novo as an essential disorder of the blood vessels of unknown cause (primary vasculitis), or it may occur in association with a known underlying disease (secondary vasculitis). A variety of common and uncommon non-vasculitis conditions may mimic vasculitis clinically and angiographically, or even histologically. These are the vasculitis look-alikes and pseudovasculitis syndromes. It is important to recognized and distinguish these vasculitis mimickers from true vasculitis so that unnecessary treatment with immunosuppressive and cytotoxic agents, all with harmful side-effects, can be avoided. Illustrated examples of many of the vasculitis mimickers are described in this review article.
A comparison of electrical and diffusion forces in the metabolism of electrolytes

Using an approximation method the electrical forces due to the metabolism of electrolytes have been compared to the ordinary diffusion forces and found negligible.
An Experimental Study of Subcooled Film Boiling on a Vertical Surface—Hydrodynamic Aspects

The aim of the present study is: (1) To determine the physical characteristics of the interfacial waves for different wall superheats and liquid subcoolings. (2) To determine the velocity field adjacent to the interface at different locations along the interface. Interface and liquid velocities near the leading edge of a vertical wall 6.3 cm wide and 10.3 cm high were measured during subcooled film boiling of water at 1 atm pressure. The interface and liquid velocities in the boundary layer adjacent to the interface were measured using the hydrogen bubble flow visualization method. Photographs taken from the front and side showed the existence of a finite vapor layer at the leading edge and the existence of ripples and large-amplitude waves (bulges) on the interface. The bulges and ripples did not slide on the interface but moved in unison with the interface. The wave amplitude and wavelength were also measured. For a given subcooling and wall superheat, the amplitude, the interfacial velocity, and the wavelength were found to attain an equilibrium value several millimeters downstream of the leading edge. The waves were highly nonlinear and the interface velocities, which are found to be governed by the wave amplitude, were much largermore » than those predicted from the smooth interface, laminar flow theory. Streamlines in the liquid were found to expand into the wave valleys. At the wave peaks the streamlines appeared to be clustered together and the measured interface velocity gradients were high. The overall picture is one of expansion in the wave valleys and contraction (of flow) at the wave peaks. The flow field in turn is found to affect the liquid side heat transfer in subcooled film boiling significantly.« less
Effect of demand prioritization and load curtailment policy on minimum emission dispatch

Abstract This paper presents a formulation of the minimum nitrogen oxide (Nox) emission dispatch that uses demand prioritization and load curtailment policy to limit the power system load during emergencies. The effects of these control strategies on the system Nox emission and the system thermal fuel costs are investigated during power system emergencies. A non-linear programming approach is used to determine the optimal values of system Nox emission, associated fuel cost and active power loss during emergencies. Different state of emergencies defined by demand prioritization and load curtailment are considered and results obtained for IEEE 30-bus test system.
Use of the rate-corrected JT interval for prediction of repolarization abnormalities in children

A prolonged rate-corrected QT interval (QTc) may be associated with an increased risk of developing ventricular arrhythmias and sudden death, particularly in patients with the hereditary long QT syndrome (LQTS), myocardial ischemia, or antiarrhythmic medication toxicity. It is known that there are some patients with LQTS who sometimes have a borderline or normal QTc (< or = 0.45 second). Although the QTc has been the standard measurement of ventricular repolarization, it includes both depolarization and repolarization and may not always be a sensitive indicator of the type of repolarization abnormalities seen in LQTS. Intraventricular conduction abnormalities complicate evaluation of the QTc interval. The rate-corrected JT interval (JTc) is a more accurate measurement of ventricular repolarization, and therefore may be a more sensitive means of assessing abnormalities. The QTc on a resting electrocardiogram was determined in 40 patients with LQTS and in 31 patients with right bundle branch block after tetralogy of Fallot repair. These were compared with 1,000 age-matched control subjects. The right bundle branch block group had normal JT and JTc measurements, despite having prolonged QT and QTc intervals compared with controls. The JTc identified 85% of patients affected with LQTS compared with only 58% identified using only the QTc as a marker for the syndrome. The JTc is a more specific measurement of ventricular repolarization than the QTc by eliminating QRS duration variability. It appears to be a more sensitive predictor of repolarization abnormalities, and may be helpful in identifying patients with LQTS who have borderline or normal QTc measurements on resting electrocardiograms.
Preparation of deuterated methyl 6,9,12-octadecatrienoates and methyl 6,9,12,15-octadecatetraenoates

Methyl 6,9,12-octadecatrienoate-15,15,16,16-d4 was obtained by Wittig coupling between 6,6,7,7-tetradeutero-3-nonenyltriphenylphosphonium iodide, 8, and the aldehyde ester, methyl 9-oxo-6-nonenoate. Methyl 6-oxohexanoate, obtained by ozonolysis of cyclohexene, was coupled in a Wittig reaction with [2-(1,3-dioxan-2-yl)ethyl]triphenylphosphonium bromide to give methyl 8-dioxanyl-6-octenoate. This compound was transacetalized to methyl 9,9-dimethoxy-6-nonenoate, which was then hydrolyzed to the aldehyde ester. For the preparation of compound 8, the tetrahydropyranyl ether of 2-pentynol was deuterated with deuterium gas and tris-(triphenylphosphine)chlororhodium. The tetradeuterated tetrahydropyranyl ether was converted to the bromide with triphenylphosphine dibromide, and the bromide was coupled with 3-butynol by means of lithium amide in liquid ammonia to give 3-nonynol-6,6,7,7-d4. Hydrogenation over Lindlar's catalyst converted the deuterated alkynol to 3-nonenol-6,6,7,7-d4. This deuterated alkenol was converted to the bromide with triphenylphosphine dibromide, then to the iodide with sodium iodide in acetone, and finally to 8 with triphenylphosphine in acetonitrile. Methyl 6,9,12,15-octadecatetraenoate-12,13,15,16-d4 was obtained by Wittig coupling between methyl 9-oxo-6-nonenoate and 3,4,6,7-tetradeutero-3,6-nonadienyltriphenylphosphonium iodide, 15. For the preparation of compound 15, the bromide obtained from the reaction of 2-pentynol with triphenylphosphine dibromide was coupled with 3-butynol with lithium amide in liquid ammonia. The resulting 3,6-nonadiynol was deuterated with deuterium gas in the presence of P-2 nickel, and the resultant deuterated nonadienol was converted to 15 through the bromide and iodide. The final products were separated from isomers formed during the synthetic sequences by silver resin chromatography.
Mapping variable—width streamside management zones for water quality protection

Streamside management is an essential part of maintaining water quality during forest operations. Maintaining forest cover and forest floor near streams has been found to minimize the impact of upslope mechanical treatments. Throughout the Southeastern US streamside management is a major component in forestry practice guidelines. Width of streamside management zone is determined in most of these guidelines as a variable, based on slope perpendicular to the stream. Although a variable width zone is advantageous for water quality protection it complicates forest operation planning. Geographic Information Systems aid management planning by accurately mapping areas where operations must be altered. In the case of streamside management zones, harvest plans must include these zones in cutting, skidding, site preparation, and road and deck placement. This paper will outline a procedure (macro language program) which allows accurate mapping of streamside management zones that vary with side slope. An accurate map of streamside management zones can be produced from a map of stream bottom position and a high resolution Digital Elevation Model. The model allows determination of the position and extent of streamside management zones during operation planning without need to resort to ground mapping during the planning stage. Model applications will be shown on small harvested watersheds. Streamside management zone mapping can also be used in the context of identifying water quality impairment on larger watersheds that include agriculture and urban development.
The Governance Challenges of the Government Performance and Results Act A Case Study of the Substance Abuse and Mental Health Administration

This study uses a case study of the Substance Abuse and Mental Health Services Administration (SAMHSA) to investigate the governance challenges of implementing the Government Performance and Results Act (GPRA) in recent years. Interdepartmental rivalry and lack of coordination, the complex relationship between the federal government and state governments in managing programs, and challenges in balancing diverse stakeholders' demands have made the strategic planning exercise of GPRA an uphill battle. The situation is further complicated by the conflicting demands from GRPA and the Performance Assessment Tool and the assertiveness of the White House in its performance budgeting initiatives in recent years. The case shows that implementation of GPRA inevitably involves many governance challenges and redistribution of power among various political actors.
On being a feminist trainer in an independent institute

This paper examines the challenges of being a feminist in an institutional setting which is not itself feminist in orientation. Dilemmas around curriculum, supervision, and relationships with both trainees and colleagues are explored. Specific suggestions are offered for how to manage some of the complexities of working within an institutional setting.
(La0.8A0.2)MnO3 (A = Sr, K) perovskite catalysts for NO and C10H22 oxidation and selective reduction of NO by C10H22

In this work, we studied the catalytic activity of LaMnO3 and (La0.8A0.2)MnO3 (A = Sr, K) perovskite catalysts for oxidation of NO and C10H22 and selective reduction of NO by C10H22. The catalytic performances of these perovskites were compared with that of a 2 wt% Pt/SiO2 catalyst. The La site substitution increased the catalytic properties for NO or C10H22 oxidation compared with the non-substituted LaMnO3 sample. For the most efficient perovskite catalyst, (La0.8Sr0.2)MnO3, the results showed the presence of two temperature domains for NO adsorption: (1) a domain corresponding to weakly adsorbed NO, desorbing at temperatures lower than 270 °C and (2) a second domain corresponding to NO adsorbed on the surface as nitrate species, desorbing at temperatures higher than 330 °C. For the Sr-substituted perovskite, the maximum NO2 yield of 80% was observed in the intermediate temperature domain (around 285 °C). In the reactant mixture of NO/C10H22/O2/H2O/He, (La0.8Sr0.2)MnO3 perovskite showed better performance than the 2 wt% Pt/SiO2 catalyst: NO2 yields reaching 50% and 36% at 290 and 370 °C, respectively. This activity improvement was found to be because of atomic scale interactions between the A and B active sites, Sr2+ cation and Mn4+/Mn3+ redox couple. Thus, (La0.8Sr0.2)MnO3 perovskite could be an alternative free noble metal catalyst for exhaust gas after treatment.
Dynamic NMR Microscopy of Gas Phase Poiseuille Flow

Abstract Dynamic NMR microscopy has been used to study xenon gas undergoing Poiseuille flow in the regime where deterministic and stochastic motions are the same order of magnitude. For short observation time, the flow profile images are largely influenced by the longitudinal diffusion, manifested by large displacements in both positive and negative directions. For longer observation time, the effect of the mixing between the fast and slow flow components due to transverse diffusion becomes apparent. A spin-echo version of the dynamic NMR experiment yields images exhibiting strong distortions for longer observation time due to fast diffusion under the “natural” gradient from magnetic field inhomogeneity (compared to results obtained with a stimulated echo version). This effect is used as an edge-enhancement filter by employing a longer time duration of the imaging gradient in a stimulated echo experiment.
A thermal study of changes in K4[Ni(NO2)6]·H2O

Abstract The dehydration of K4[Ni(NO2)6]·H2O has been studied using TG and DSC. The TG results permit the determination of the activation energy for dehydration to be determined, and a value of 178 kJ mole−1 was obtained. Analysis of the DSC curves enable two limiting processes having activation energies of 228 and 97.9 kJ mole−1 to be identified. These are attributed to the dehydration and linkage isomerization processes, respectively. The isomerization process is interpreted in terms of an intramolecular mechanism.
Intratracheal Granuloma Formation: A Late Complication of Marlex Mesh Splinting for Tracheomalacia

External splinting of the trachea has been used alone or in combination with aortopexy for the treatment of severe tracheomalacia. The authors describe the case of a 12-year-old boy who had a Marlex mesh splint placed because of life-threatening primary tracheomalacia at 6 months of age. He presented at 12 years of age with a 5-month history of shortness of breath on exertion, dry cough, and audible wheeze. Radiological and endoscopic examinations showed near-complete obstruction of the orifice of the right mainstem bronchus by a large polypoid granuloma. Initially the patient was treated with endoscopic resection on two occasions, but the granuloma and bronchial obstruction recurred each time. He underwent a right thoracotomy, which showed that the lower edge of the mesh had eroded through the trachea wall and was acting as a nidus for granuloma formation. After removal of the mesh, the resulting defect at the site of erosion of the trachea was closed with a pericardial patch. The postoperative course was uncomplicated, and the patient remains well 2 years after surgery. External splinting of the trachea has been shown to be effective in the treatment of complicated tracheomalacia, but one must be aware of the potential long-term complications, as demonstrated in this case.
Effects of the Landscape on Shorebird Movements at Spring Migration Stopovers

We monitored the inter-wetland movements of 115 radio-tagged Pectoral Sand-pipers (Calidris melanotos) at three migration stopovers in the Great Plains of North America during April and May from 1992 to 1995. While resident at a stopover, individuals were very localized in their movements. Over 40% of the birds made no inter-wetland movements, and over 90% of individuals moved less than 10 km from their original release site. Characteristics of wetlands where birds were released did not affect bird movements. However, the structure of the surrounding landscape explained up to 46% of variation in individual bird movements. As the distance between wetlands decreased, and the proportion of the landscape composed of wetlands increased, individual birds moved between wetlands more frequently and moved longer distances from their release site. These movement patterns indicate that a more connected landscape allows shorebirds to exploit more feeding sites with reduced searching costs; a result consistent with foraging theory. We estimate a degree of landscape connectivity at which a wetland complex functions as a single large wetland as measured by sandpiper feeding patterns. Our data provide support for the idea that complexes of small, closely spaced wetlands can be important migration stopovers and may have significant conservation value.
Control of cartographic materials in archives

Archival repositories are a major source of cartographic information useful for many kinds of research. Access to these cartographic resources is an integral part of their availability and is related to the general principles of archival arrangement and description. The automation of archival access using the MARC Format for Archives and Manuscripts Control has created great changes in archival description practices. Although there has been a MARC Format for Maps for several years, this format is not as useful for the description of cartographic archives and archivists have not yet developed the generally accepted standards needed to make these materials accessible to a wide range of users. This paper discusses the differences in archival and bibliographic description of maps and suggests some possible options for standards development in the control of cartographic archives.
The fluorocarbon ozone theory—VII. One-dimensional modeling—An assessment of anthropogenic perturbations

Abstract An updated version of a one-dimensional chemical model is described, together with a simple approach to diurnal calculations. The model is used to investigate the possible effects on model predictions of new chemistry, such as bromine and HOCl chemistry, to compare calculated species profiles with experiment, and to evaluate, within the present chemical scheme, the magnitude of a variety of potential perturbations to stratospheric ozone. In particular the ozone depletion calculated for steady state fluorocarbon release at 1975 levels is 18.3% and it is shown that this number would be halved by doubling the current ground level N 2 O flux.
Symplectic integration of Hamiltonian wave equations

The numerical integration of a wide class of Hamiltonian partial differential equations by standard symplectic schemes is discussed, with a consistent, Hamiltonian approach. We discretize the Hamiltonian and the Poisson structure separately, then form the the resulting ODE's. The stability, accuracy, and dispersion of different explicit splitting methods are analyzed, and we give the circumstances under which the best results can be obtained; in particular, when the Hamiltonian can be split into linear and nonlinear terms. Many different treatments and examples are compared.
Kinetic studies of the human renin and human substrate reaction

Abstract The hydrolysis of human renin substrate by human renin was studied simultaneously in sera of women receiving or not receiving oral contraceptives. The kinetic parameters K m and V m of the Michaelis-Menten equation and the relevant standard errors were estimated by Wilkinson's method for the statistical analysis of kinetic data. Significant differences in the kinetic constants between these two groups were not observed. These studies indicate that the higher velocity in sera from women receiving estrogen is related to the substrate concentration rather than modifying factors or multiple forms of renin substrate.
Replication and infectivity of the nuclear polyhedrosis virus of the alfalfa looper, Autographa californica, produced in cells grown in vitro

Abstract A virus isolated from the alfalfa looper, Autographa californica, replicated successfully and rapidly in a suspended ovarian cell line of the cabbage looper, Trichoplusia ni. Polyhedra were observed in the nucleus of cells within 20 hr after inoculation. The cytopathological changes typical of nuclear polyhedrosis infections were observed, and an average of 64 polyhedra/cell were produced. These polyhedra were quantitatively as infectious to cabbage looper larvae as those produced in vivo. In addition, they were infective to Heliothis virescens, Pectinophora gossypiella, Spodoptera exigua, A. californica, and Anagrapha falcifera.