cssi/SciSciGPT-SciSciNet huggingface dataset:
Forging a silver bullet from the essence of software

Most improvements in software development technology have occurred by eliminating the accidental aspects of the technology. Further progress now depends on addressing the essence of software. Fred Brooks has characterized the essence of software as a complex construct of interlocking concepts. He concludes that no silver bullet will magically reduce the essential conceptual complexity of software. This paper expands on Brooks's definition to lay a foundation for forging a possible silver bullet. Discussed are the three essential attributes of software entities from which a number of consequences arise in software development: (1) conceptual content, (2) representation, and (3) multiple subdomains. Four basic approaches to develop technologies are proposed that directly address the essential attributes. Although some of these technologies require additional development or testing, they present the most promise for forging a silver bullet. Among them, design reabstraction addresses the most difficult attribute, multiple subdomains, and the most difficult consequence, enhancing existing code, making it the best prospect.
The ability of acidic pH, growth inhibitors, and glucose to increase the proton motive force and energy spilling of amino acid-fermenting Clostridium sporogenes MD1 cultures

Clostridium sporogenes MD1 grew rapidly with peptides and amino acids as an energy source at pH 6.7. However, the proton motive force (Δp) was only −25 mV, and protonophores did not inhibit growth. When extracellular pH was decreased with HCl, the chemical gradient of protons (ZΔpH) and the electrical membrane potential (ΔΨ) increased. The Δp was −125 mV at pH 4.7, even though growth was not observed. At pH 6.7, glucose addition did not cause an increase in growth rate, but ΔΨ increased to −70 mV. Protein synthesis inhibitors also significantly increased ΔΨ. Non-growing, arginine-energized cells had a ΔΨ of −80 mV at pH 6.7 or pH 4.7, but ΔΨ was not detected if the F1F0 ATPase was inhibited. Arginine-energized cells initiated growth if other amino acids were added at pH 6.7, and ΔΨ and ATP declined. At pH 4.7, ATP production remained high. However, growth could not be initiated, and neither ΔΨ nor the intracellular ATP concentration declined. Based on these results, it appears that C. sporogenes MD1 does not need a large Δp to grow, and Δp appears to serve as a mechanism of ATP dissipation or energy spilling.
Seasonal transfer and net accumulation of fine sediment on a muddy tidal flat: Willapa Bay, Washington

Abstract Tidal flats act as natural laboratories in which fundamental sediment-transport processes can be directly related to resulting seabed deposits. These environments represent important repositories for terrestrial particles (including organic carbon) entering marine dispersal systems. Along the coast of the US Pacific Northwest, tides, waves, currents, and storms create year-round energetic environments that evolve on myriad time scales, from semi-diurnal to interannual. In southern Willapa Bay, WA, an extensive tidal flat is accreting at a distance away from local fluvial sources. During winter, freshwater input and the peak suspended-sediment concentration (SSC) are one-to-two orders of magnitude greater than in summer, and wind- and wave-generated shear stresses prevent sediment from accumulating on the tidal flat. Temporary deposits form as a drape across secondary channels off the Bear River Channel. Sedimentary structures from these deposits reveal 15–30 cm of physically stratified sediment underlain by a discrete shell-hash layer 2–8 cm thick. The presence of relatively uniform excess 210 Pb activities in the sediment above the shell hash, and only supported activities below indicate rapid deposition of the surficial sediment. During summer, the distribution of bed shear stresses is not significantly weaker than in winter due to the effect of local basin geometry on fetch, yet the SSC is much less, likely due to reduced fluvial sediment supply and enhanced benthic biological factors. Progressively through the summer, tidal currents and wind waves remove the temporary channel deposits and expose the buried shell-hash layer, and concurrent seabed changes allow the tidal flats to trap this remobilized sediment. Accumulation rates determined by 210 Pb analysis for cores collected on the tidal flats show mean accretion at 1.4 mm/yr, which can be accounted for by local river sources. The mass of sediment stored in the temporary channel drapes during winter is approximately the same as the annual tidal-flat accumulation in the vicinity of these channels. This agreement suggests a mechanism by which sediment temporarily stored in winter channel deposits is subsequently reworked during summer, and transferred onto the tidal flats. The accumulation rate on the flats approximately matches local sea-level rise, which implies this system accretes over longer time scales in equilibrium with the space provided. The preservation of layered deposits (65–90 cm thick) buried 155–230 cm beneath the modern surface suggests that the past accommodation space was greater than at present. Coseismic subsidence during Cascadia earthquakes represents a possible mechanism by which vertical space can be created.
Presence of oncornavirus-like particles in the P388 murine leukemic cell line

A culture of P388 murine lymphoblastoid cells has been shown to contain type C oncornavirus-like particles budding at the plasma membrane. Occasionally intracytoplasmic type A and immature type B particles were also observed by electron microscope techniques. The discovery of oncornavirus-like particles in the P388 cell line increases the utility of this neoplastic system for detecting potential antineoplastic agents.
A Case History of Sea Lamprey Control in Lake Michigan: 1979 to 1999

The sea lamprey (Petromyzon marinus) control program, along with the stocking of native fish species, the introduction of Pacific salmon, and the application of regulations controlling harvest, has allowed the socioeconomic and biological recovery of the Lake Michigan fishery which has been described as “spectacular.” The program is now instrumental in maintaining today's fish community structure. Initial treatment of Lake Michigan tributaries with the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) reduced the number of spawning-phase sea lampreys by 85% and resulted in a noticeable recovery of the Lake Michigan fishery by 1979. Prior to 1979, sea lampreys were present in 115 of the 511 tributaries of Lake Michigan. Sea lampreys were found in four additional streams between 1978 and 1999. The greatest number of parasitic-phase sea lampreys are produced in 34 streams tributary to Lake Michigan. Between 1960 and 1999, 730 treatments were conducted in 113 Lake Michigan tributaries. The six remaining streams were not treated because few sea lampreys were present. The average number of streams treated annually declined from 21 during 1970–1979 to 12 during 1990–1999. Thirty eight percent less TFM (active ingredient) was applied annually, on average, in 1990 to 1999 (192 kg/m3 of stream discharge) than in 1960 to 1969 (310 kg/m3 of stream discharge). Barriers specifically constructed or modified to block migrating sea lampreys are currently found on 12 Lake Michigan streams. An additional 27 potential barrier sites have been identified on Lake Michigan streams. The estimated numbers of parasitic-phase sea lampreys in Lake Michigan between 1977 and 1999 ranged from 32,000 (1979) to 105,900 (1998). The incidence of fresh sea lamprey wounds on lake trout (Salvelinus namaycush) in Lake Michigan was generally less than five per 100 fish in most years since 1971. Sea lampreyinduced mortality increased steadily in the 1990s, especially among large lake trout. Most mortality was in northern Lake Michigan where lake trout are more likely to be attacked by sea lampreys because of the large sea lamprey population.
Porcine circovirus type 2 in muscle and bone marrow is infectious and transmissible to naïve pigs by oral consumption.

Pork products are a possible source of introduction of PCV2 isolates into a pig population. However, limited work has been done on the transmission through meat of porcine circovirus type 2 (PCV2), a virus associated with several disease syndromes in pigs. The objectives of this study were to determine if pork products from PCV2-infected pigs contain PCV2 DNA/antigen and to determine if the PCV2 present in the tissues is infectious by performing in vitro and in vivo studies. Skeletal muscle, bone marrow, and lymphoid tissues from pigs experimentally inoculated with PCV2 were collected 14 days post-inoculation (DPI). The tissues were tested for presence of PCV2 DNA by quantitative real-time PCR, for PCV2 antigen by immunohistochemistry (IHC), and for presence of infectious PCV2 by virus isolation and inoculation of PCV2 naive pigs. Lymphoid tissues contained the highest amount of PCV2 (positive by PCR, IHC, and virus isolation), bone marrow contained a lower amount of PCV2 (positive by PCR and IHC but negative by virus isolation), and skeletal muscle contained the lowest amount of PCV2 (positive by PCR but negative by IHC and virus isolation). Naive pigs fed for three consecutive days with either skeletal muscle, bone marrow, or lymphoid tissues all became PCV2 viremic as determined by quantitative real-time PCR on serum starting at 7 DPI. The pigs also seroconverted to PCV2 as determined by PCV2 IgM and IgG ELISA. In addition, PCV2 antigen was detected by IHC stains in lymphoid tissues and intestines collected from the majority of these pigs. Results from this study indicate that uncooked PCV2 DNA positive lymphoid tissues, bone marrow, and skeletal muscle from PCV2 viremic pigs contain sufficient amount of infectious PCV2 to infect naive pigs by the oral route.
Adrenal steroid regulation of neurotrophic factor expression in the rat hippocampus.

Adrenal steroids and neurotrophic factors are important modulators of neuronal plasticity, function, and survival in the rat hippocampus. Adrenal steroids act through two receptor subtypes, the glucocorticoid receptor (GR) and the mineralocorticoid receptor, and activation of each receptor subtype has distinct biochemical and physiological consequences. Adrenal steroids may exert their effects on neuronal structure and function through the regulation of expression of neurotrophic and growth-associated factors. We have examined adrenal steroid regulation of the neurotrophins brain-derived neurotrophic factor, neurotrophin-3, and basic fibroblast growth factor, as well as the growth associated protein GAP-43, through activation of GR or mineralocorticoid receptor with selective agonists. Our findings indicated that in CA2 pyramidal cells, adrenalectomy resulted in decreases in the levels of basic fibroblast growth factor and neurotrophin-3 messenger RNA, which were prevented by activation of mineralocortico...
Synergistic assembly of dendrimer-templated platinum catalysts on nitrogen-doped carbon nanotube electrodes for oxygen reduction.

A study of the synergistic tuning of nitrogen-doped carbon nanotubes (NCNTs) as support- and size-monodisperse platinum nanoparticles templated from G4-NH2 dendrimers (Pt-DEN's) as catalysts targeted toward oxygen reduction is reported. UV−vis spectroscopy, adsorption isotherms, TGA, TEM, and voltammetry were used to characterize the loading and activity of Pt-DENs immobilized on CNT and NCNT supports. The facile uptake of Pt-DENs was found to be influenced by the number of edge plane sites on the NCNT support with higher adsorption rates observed for NCNTs with increased nitrogen content. Pt-DEN/NCNT composites exhibit high activity with a mass-transport-limited current density and mass activity of 2.3 mA cm-2 and 0.05 mA g-1, respectively, for the oxygen reduction reaction (ORR).
Chronic Tinnitus Resulting From Head or Neck Injuries

Objectives The main objectives were 1) to determine the percentage of cases of chronic tinnitus in a specialized clinic that resulted from head or neck injuries; 2) to describe the characteristics of this population; and 3) to compare patients with head or neck trauma with patients whose tinnitus onset was not associated with head or neck injuries. Study Design Retrospective analysis of tinnitus clinic patient data. Methods Detailed questionnaires were mailed to 2400 patients before their initial appointment at the Oregon Health and Science University Tinnitus Clinic (Portland, OR). All of the patients experienced and received treatment for chronic tinnitus. Patient data were entered into a database and later analyzed. Results Two hundred ninety-seven patients (214 male and 83 female patients) reported that their chronic tinnitus started as a result of head or neck injuries. Compared with patients whose tinnitus onset was not associated with trauma, patients with tinnitus associated with head or neck trauma were younger; had better hearing thresholds; experienced headaches more frequently; reported greater difficulties with concentration, memory, and thinking clearly; were more likely to experience current depression, but not lifetime depression; rated their tinnitus as louder on a 1-to-10 scale; matched their tinnitus to louder sounds on the right side; and had higher Tinnitus Severity Index scores. Conclusions Tinnitus is a significant symptom that commonly occurs as a result of head or neck trauma. The fact that tinnitus resulting from head or neck injuries tends to be more severe (and is often accompanied by a greater number of co-symptoms) than tinnitus resulting from other causes should be taken into account by clinicians treating these patients.
Solution conformation of a five-nucleotide RNA bulge loop from a group I intron.

We present the solution conformation, determined by NMR spectroscopy, of a five-nucleotide RNA bulge loop. The bulge interrupts the stem of a 25-nucleotide RNA hairpin, and its sequence and flanking sequences are those of a conserved bulge from a Group I intron. The secondary structure of the bulge loop in the hairpin context is that predicted by the secondary structure prediction algorithm of Zuker. It differs, however, from the secondary structure deduced from sequence covariation of the bulge in the context of the functionally folded Group I introns and observed in the crystal structure of an independently folding domain of the Group I intron from Tetrahymena thermophila. This difference represents an exception to the heierarchical model of RNA folding in which preformed elements of secondary structure interact to form a tertiary structure. The three-dimensional structure of the bulge loop is characterized by discontinuous base stacking. Adjacent adenines stack with each other and with the flanking dou...
Carbon monoxide levels among patrons of hookah cafes

Background Individuals who use a hookah (water pipe) as a method of tobacco smoking are exposed to high levels of carbon monoxide (CO). Assessing hookah use in one of the venues of its use (hookah bars) will aid the understanding of the toxins and exposure for the user. In Florida, smoking is prohibited in public places under the Florida Clean Indoor Act but permitted in establishments that have less than 10% gross revenue from food. Purpose To assess the CO level of hookah cafe patrons, using traditional bar patrons as a comparison. Methods After IRB approval, a nighttime field study of patrons (aged >18 years) exiting hookah cafes and traditional bars in 2009 was conducted, using sidewalk locations immediately outside these establishments in a campus community. As hookah cafes and bars are typically entered and exited in groups, every other group of people exiting the establishment was approached. For comparison purposes, the sample collected was similar in number, 173 hookah cafe and 198 traditional bar participants. Results Results from analysis conducted in 2010 indicate that patrons of hookah cafes had significantly higher CO levels (mean=30.8 parts per million [ppm]) compared to patrons of traditional bars (mean=8.9 ppm). Respondents who indicate no cigarette use in the past month but had visited a hookah cafe still demonstrated significantly higher CO values (mean=28.5 ppm) compared to those exiting traditional bars (mean=8.0 ppm). Current cigarette smokers also produced significantly more CO if exiting a hookah cafe (mean=34.7 ppm) compared to a traditional bar (mean=13.3 ppm). Conclusions CO levels are higher for patrons of hookah cafes, for both current and non-cigarette smokers. Although users report that they perceive hookah to be less harmful than cigarettes, the greater CO exposure for hookah users that was observed in this study is not consistent with that perception.
Extensions of subgradient projection algorithms

Abstract The validity of the subgradient projections algorithms ( V. P. Sreedharan , J. Approx. Theory 41 (1984), 217–243; 35 (1982), 111–126) is extended by removing part of the previous assumptions on the objective function. The appropriate modifications in the algorithms and their proofs of convergence are then given.
Wall-induced lift on a sphere

Abstract The lateral migration of rigid spheres sedimenting near a large flat vertical wall, in a quiescent Newtonian fluid, has been studied experimentally. The migration velocities were measured by recording the trajectory of the spheres as they sedimented near a wall for the particle Re range 0.1–10.0. The measurements indicate that the expression derived by Vasseur & Cox [J. Fluid Mech. 80, 561–591 (1977)] predicts, fairly accurately, the migration velocity up to a particle Re of 3.0.
Electrospray ionization of volatiles in breath

Abstract Recent work by Zenobi and colleagues [H. Chen, A. Wortmann, W. Zhang, R. Zenobi, Angew. Chem. Int. Ed. 46 (2007) 580] reports that human breath charged by contact with an electrospray (ES) cloud yields many mass peaks of species such as urea, glucose, and other ions, some with molecular weights above 1000 Da. All these species are presumed to be involatile, and to originate from breath aerosols by so-called extractive electrospray ionization EESI [H. Chen, A. Venter, R.G. Cooks, Chem. Commun. (2006) 2042]. However, prior work by Fenn and colleagues [C.M. Whitehouse, F. Levin, C.K. Meng, J.B. Fenn, Proceedings of the 34th ASMS Conference on Mass Spectrometry and Allied Topics, Denver, 1986 p. 507; S. Fuerstenau, P. Kiselev, J.B. Fenn, Proceedings of the 47th ASMS Conference on Mass Spectrometry, 1999, Dallas, TX, 1999] and by Hill and colleagues [C. Wu, W.F. Siems, H.H. Hill Jr., Anal. Chem. 72 (2000) 396] have reported the ability of electrospray drops to ionize a variety of low vapor pressure substances directly from the gas phase, without an apparent need for the vapor to be brought into the charging ES in aerosol form. The Ph.D. Thesis of Martinez-Lozano [P. Martinez-Lozano Sinues, Ph.D. Thesis, Department of Thermal and Fluid Engineering, University Carlos III of Madrid; April 5, 2006 (in Spanish); http://hdl.handle.net/10016/655 ] had also previously argued that the numerous human breath species observed via a similar ES ionization approach were in fact ionized directly from the vapor. Here, we observe that passage of the breath stream through a submicron filter does not eliminate the majority of the breath vapors seen in the absence of the filter. We conclude that direct vapor charging is the leading mechanism in breath ionization by electrospray drops, though aerosol ionization may also play a role.
Transitional Liquid Crystalline Phases between the Hexagonal and Lamellar Phases in Ternary Cesium N-Tetradecanoate-Water-Additive Mixtures

Abstract The effects of added salt (CsOH, CsCl), long-chain carboxylic acid, and long-chain alcohol on the lyotropic liquid crystalline phase behavior in the cesium n-tetradecanoate (CsTD)-water system is reported. The transitional region between the hexagonal (Hα) and lamellar (Lα) phases was the compositional range of focus. Three transitional phases were observed: (i) the ribbon (R) phase, a biaxial phase consisting of cylinders of ellipsoidal cross section; (ii) the viscous isotropic (VI) phase, an isotropic phase thought to consist of interconnected rods on an 1a3d lattice; and (iii) the intermediate (Int) phase, a uniaxial anisotropic phase thought to consist of interconnected rods on a planar lattice. The effect of the additives was to decrease the "interfacial curvature" of the surfactant head group layer by varying head group repulsion and by varying the surfactant tail volume relative to the surfactant head group area. These changes resulted in formation of transitional phases seeming to possess curvature between that of the cylindrical Hα phase and the planar Lα phase. The ionic repulsion between carboxylate head groups was reduced by the addition of CsOH or CsCl, and resulted in destabilization of the VI phase and the formation of the anisotropic Int phase. With the addition of cosurfactants, n-tetradecanoic acid (TDA) and 1-tetradecanol (TDOH), no Int phase was observed. With 7 wt% added TDA the R phase was stabilized up to temperatures of 336 K, above the 330 K temperature limit in the binary CsTD-D2O system. In all four systems, sufficient additive (5-10 wt%) resulted in a transition to the Lα phase, which was stable over a large portion of the compositional range. In order of apparently decreasing mean curvature, the phase sequence is: hexagonal, ribbon, viscous isotropic, intermediate, and lamellar. The inferred structures are remarkably similar to reports in sodium dodecyl sulfate- and alkyl trimethyl ammonium chloride-water binary systems, as well as to liquid crystal formation in block copolymer systems.
Reserpine labels the catecholamine transporter in synaptic vesicles from bovine caudate nucleus.

Abstract Tritiated reserpine binds to synaptic vesicles from bovine caudate with high affinity (Kappd = 1.25 nM, Bmax = 3.3 pmol/mg protein). This interaction is both ATP-dependent and sensitive to the protonophores CCCP and nigericin, suggesting that a proton electrochemical gradient is required for binding. Dopamine, epinephrine, norepinephrine and serotonin all inhibit reserpine binding at concentrations similar to those required for inhibition of dopamine uptake. Treatment with saponin to release vesicle contents results in complete loss of accumulated dopamine but retention of bound reserpine. these results indicate that reserpine binds to the catecholamine transport system of synaptic vesicles with high affinity and specificity.
Isolation and Characterization of the Neutral Leucine Aminopeptidase (LapN) of Tomato

Tomatoes (Lycopersicon esculentum) express two forms of leucine aminopeptidase (LAP-A and LAP-N) and two LAP-like proteins. The relatedness of LAP-N and LAP-A was determined using affinity-purified antibodies to four LAP-A protein domains. Antibodies to epitopes in the most N-terminal region were able to discriminate between LAP-A and LAP-N, whereas antibodies recognizing central and COOH-terminal regions recognized both LAP polypeptides. Two-dimensional immunoblots showed that LAP-N and the LAP-like proteins were detected in all vegetative (leaves, stems, roots, and cotyledons) and reproductive (pistils, sepals, petals, stamens, and floral buds) organs examined, whereas LAP-A exhibited a distinct expression program. LapN was a single-copy gene encoding a rare-class transcript. A full-length LapN cDNA clone was isolated, and the deduced sequence had 77% peptide sequence identity with the wound-induced LAP-A. Comparison of LAP-N with other plant LAPs identified 28 signature residues that classified LAP proteins as LAP-N or LAP-A like. Overexpression of a His6-LAP-N fusion protein in Escherichia coli demonstrated distinct differences in His6-LAP-N and His6-LAP-A activities. Similar to LapA, the LapN RNA encoded a precursor protein with a molecular mass of 60 kD. The 5-kD presequence had features similar to plastid transit peptides, and processing of the LAP-N presequence could generate the mature 55-kD LAP-N. Unlike LapA, the LapN transcript contained a second in-frame ATG, and utilization of this potential initiation codon would yield a 55-kD LAP-N protein. The localization of LAP-N could be controlled by the balance of translational initiation site utilization and LAP-N preprotein processing.
Reductive activation of fructose-1,6-bisphosphatase and the peroxide effect on chloroplast photosynthesis.

Abstract Studies of isolated intact spinach chloroplasts reveal most of the available sulfhydryl groups are associated with stromal protein as opposed to a thylakoid membrane fraction under nondenaturing conditions. Increases in sulfhydryl content of about 45% occurred with illumination and could be correlated with reductive activation of fructose-1,6-bisphosphatase during CO2 assimilation. The omission of catalase inhibited net photosynthesis and caused a lower sulfhydryl number along with diminished fructose-1,6-bisphosphatase activity. Subsequent additions of 0.3 m m NH4Cl accelerated oxygen evolution while both the sulfhydryls and fructose-1,6-bisphosphatase rate were restored to their control values. Peroxide additions extended the initial lag period before the onset of photosynthetic oxygen production and also inhibited the rate if added during continuous illumination. In both cases, fructose-1,6-bisphosphatase activity was similar to that observed in the absence of catalase. The relative sulfhydryl content also remained unchanged. Preincubation of extracts from illuminated chloroplasts in 0.66 m m peroxide did not significantly alter fructose-1,6-bisphosphatase rates whereas CuSO4 drastically inhibited activity and diminished the sulfhydryl number. These results suggest it is unlikely that peroxide alone induces re-formation of disulfide bridges in fructose-1,6-bisphosphatase and causes photosynthetic inhibition. However, the light-activated form of the enzyme is quite sensitive to a mild copper-induced oxidation in vitro and appears to be similarly affected within the chloroplast when both peroxide and the metal catalyst are present.
Toxicity of copper to early-life stage Kootenai River white sturgeon, Columbia River white sturgeon, and rainbow trout.

White sturgeon (Acipenser transmontanus) populations throughout western North America are in decline, likely as a result of overharvest, operation of dams, and agricultural and mineral extraction activities in their watersheds. Recruitment failure may reflect the loss of early-life stage fish in spawning areas of the upper Columbia River, which are contaminated with metals from effluents associated with mineral-extraction activities. Early-life stage white sturgeon (A. transmontanus) from the Columbia River and Kootenai River populations were exposed to copper during 96-h flow-through toxicity tests to determine their sensitivity to the metal. Similar tests were conducted with rainbow trout (RBT [Oncorhynchus mykiss]) to assess the comparative sensitivity of this species as a surrogate for white sturgeon. Exposures were conducted with a water quality pH 8.1–8.3, hardness 81–119 mg/L as CaCO2, and dissolved organic carbon 0.2–0.4 mg/L. At approximately 30 days posthatch (dph), sturgeon were highly sensitive to copper with median lethal concentration (LC50) values ranging from 4.1 to 6.8 μg/L compared with 36.5 μg/L for 30 dph RBT. White sturgeon at 123–167 dph were less sensitive to copper with LC50 values ranging from 103.7 to 268.9 μg/L. RBT trout, however, remained more sensitive to copper at 160 dph with an LC50 value of 30.9 μg/L. The results indicate that high sensitivity to copper in early-life stage white sturgeon may be a factor in recruitment failure occurring in the upper Columbia and Kootenai rivers. When site-specific water-quality criteria were estimated using the biotic ligand model (BLM), derived values were not protective of early-life stage fish, nor were estimates derived by water-hardness adjustment.
Patellofemoral joint stress during stair ascent and descent in persons with and without patellofemoral pain

Objective: To determine if persons with patellofemoral pain (PFP) demonstrate elevated patellofemoral joint (PFJ) stress during stair ascent and descent when compared to persons without PFP. Design: A cross sectional study utilizing an experimental and a control group. Background: Ascending and descending stairs is one of the most painful activities of daily living for persons with PFP. Whether or not the pain associated with stair ambulation is the result of elevated joint stress (force per unit area) has not been explored. Methods: 10 subjects with a diagnosis of PFP and 10 subjects without pain completed two phases of data collection, (1) MRI assessment to determine PFJ contact area and (2) comprehensive motion analysis during stair ambulation at self selected climbing velocities. Data obtained from both data collection sessions were utilized as input variables into a biomechanical model to quantify PFJ stress. Results: Although the knee extensor moment and PFJ reaction force (PFJRF) were significantly reduced in the PFP subjects during stair ascent, there was no difference in PFJ stress between groups. Similarly, there were no differences in PFJ stress during stair descent. Conclusion: Our results do not support the hypothesis that subjects with PFP demonstrate greater joint stress during stair ascent and descent compared to subjects without pain. However, subjects with PFP appeared to maintain normal levels of PFJ stress by minimizing the PFJRF. This was accomplished through a slower cadence and a reduced knee extensor moment. Relevance: PFP is a common syndrome causing pain and functional limitations during stair climbing and other activities requiring high levels of quadriceps activity. Information obtained from this study will be useful in understanding the biomechanical mechanisms contributing to functional deficits in the PFP population.
Prey capture kinematics and four-bar linkages in the bay pipefish, Syngnathus leptorhynchus.

Abstract Because of their modified cranial morphology, syngnathid pipefishes have been described as extreme suction feeders. The presumption is that these fishes use their elongate snout much like a pipette in capturing planktonic prey. In this study, we quantify the contribution of suction to the feeding strike and quantitatively describe the prey capture mechanics of the bay pipefish Syngnathus leptorhynchus, focusing specifically on the role of both cranial elevation and snout movement. We used high-speed video to capture feeding sequences from nine individuals feeding on live brine shrimp. Sequences were digitized in order to calculate kinematic variables that could be used to describe prey capture. Prey capture was very rapid, from 2 to 6 ms from the onset of cranial rotation. We found that suction contributed at most about one-eighth as much as ram to the reduction of the distance between predator and prey. This movement of the predator was due almost exclusively to movement of the snout and neurocranium rather than movement of the whole body. The body was positioned ventral and posterior to the prey and the snout was rotated dorsally by as much as 21°, thereby placing the mouth immediately behind the prey for capture. The snout did not follow the identical trajectory as the neurocranium, however, and reached a maximum angle of only about 10°. The snout consists, in part, of elongate suspensorial elements and the linkages among these elements are retained despite changes in shape. Thus, when the neurocranium is rotated, the four-bar linkage that connects this action with hyoid depression simultaneously acts to expand and straighten the snout relative to the neurocranium. We confirm the presence of a four-bar linkage that facilitates these kinematics by couplings between the pectoral girdle, urohyal, hyoid complex, and the neurocranium–suspensorium complex.
Kinoform lens focusing of high-energy x-rays (50 - 100 keV)

High-energy x-rays from a synchrotron source are well suited for numerous applications, such as studies of materials structure and stress in bulk or extreme environments. Some of these methods require high spatial resolution. Planar kinoforms are shown to focus monochromatized undulator radiation in the 50–100 keV range down to 0.2–1.5 μm beam sizes at 0.25–2 m focal distances. These lenses were fabricated by reactive ion etching of silicon. At such high x-ray energies, these optics can offer substantial transmission and lens aperture.
Algorithmic Equivalence in Linear Fractional Programming

This paper demonstrates the equivalence of several published algorithms for solving the so-called linear fractional programming problem.
Miniband-gap optical excitations in doped semiconductor superlattices

Abstract We study the far-infrared response of a doped semiconductor superlattice by calculating the RPA dielectric function in the long-wavelength limit. The energy level structure and wavefunctions are obtained using a tight-binding envelope-function approximation, where inhomogeneous potentials related to depletion regions in real systems have been incorporated selfconsistently in a two-miniband model. Fermi-level pinning associated with depletion regions at the ends of the superlattice gives rise to surfacelike states lying in the miniband gaps and exhibiting localized eigenstates. The absorption peaks involving excitations to and from these surfacelike states are clearly distinguishable from the normal intra- and inter-miniband background. The resulting midgap peaks can be easily shifted within the minigap by applying a gate voltage across the structure. This suggests novel far-infrared optoelectronic devices.
Locked modes and magnetic field errors in the Madison Symmetric Torus

In the Madison Symmetric Torus (MST) reversed‐field pinch [Fusion Technol. 19, 131 (1991)] magnetic oscillations become stationary (locked) in the lab frame as a result of a process involving interactions between the modes, sawteeth, and field errors. Several helical modes become phase locked to each other to form a rotating localized disturbance, the disturbance locks to an impulsive field error generated at a sawtooth crash, the error fields grow monotonically after locking (perhaps due to an unstable interaction between the modes and field error), and over tens of milliseconds of growth confinement degrades and the discharge eventually terminates. Field error control has been partially successful in eliminating locking.
Dolomite in Modern Carbonate Sediments, Southern Florida: ABSTRACT

The western margin of Florida Bay contains extensive shallow-water banks of unconsolidated, fine carbonate mud. The banks are separated by narrow tide channels and rest on hard Pleistocene bedrock. The banks attain a maximum thickness of about 4½ feet. Radiocarbon dates show that they have been formed in the past 4,000 years. The carbonate mud is composed principally of aragonite, with lesser proportions of dolomite and both high- and low-magnesium calcite. The proportion of dolomite varies, ranging up to about 5 per cent by weight of the total carbonate. Other constituents are quartz and opaline sponge spicules, but these rarely form more than 1 or 2 per cent. Dolomite crystals are euhedral rhombohedrons varying in size from less than 1 micron to approximately 60 microns. They commonly have dark internal rhombohedrons that appear to be intergrowths of dolomite and organic materials. Complex clusters of interpenetrating rhombohedrons are present, but are rare. The occurrence of interpenetrating rhombohedrons and intergrowtbs of organic and carbonate material suggests that dolomite has been formed in situ in Florida Bay; however, radiocarbon dating shows that the dolomite is older than 35,000 years and must be detrital. End_of_Article - Last_Page 281------------
The relativistic correction to the excitation energy of formaldehyde

Abstract First-order perturbation theory for the mass-velocity, Darwin, and magnetic corrections was used with a non-relativistic wavefunction to calculate relativistic contributions to the ground and 3 A 2 , 3 A', 3 A 1 , 2 B 2 , and 2 B 1 excited states of Corrections to the excitation energy were found to be in the range of 30–80 cm −1 .
Activation of α2-adrenergic receptors decreases Ca2+ influx to inhibit insulin secretion in a hamster β-cell line : an action mediated by a guanosine triphosphate-binding protein

Activation of the sympathetic nervous system inhibits insulin secretion. We tested the hypothesis that activation of alpha 2-adrenergic receptors on the beta-cell by epinephrine or clonidine attenuates insulin release by an effect on the voltage-dependent Ca2+ channel (VDCC) and examined the role of G-proteins in this signal transduction pathway. Using a cultured SV40-transformed hamster beta-cell line (HIT cells) as a model system, we determined the effect of alpha 2-adrenergic agonists on insulin secretion, 86Rb+ efflux (a marker for K+ channel flux), and the free cytosolic Ca2+ level [( Ca2+]i) monitored in fura-2-loaded cells. In a dose-dependent manner, epinephrine and clonidine (10(-8)-10(-5)M) attenuated the increase in [Ca2+]i and insulin secretion induced by either K+ depolarization or stimulation of the VDCC with the agonist Bay K 8644. Epinephrine failed to affect the rise in [Ca2+]i induced by carbamylcholine, an agent that mobilizes intracellular Ca2+. Epinephrine also did not changes 86Rb+ efflux from HIT cells. The inhibitory effects of epinephrine were prevented by the alpha 2-adrenergic antagonist idazoxan, but were unaffected by the alpha 1-adrenergic antagonist phenoxybenzamine. Pretreatment of HIT cells with pertussis toxin (0.1 micrograms/ml) overnight abolished the inhibitory effects of epinephrine and clonidine on both [Ca2+]i and insulin secretion. These data suggest that one mechanism by which alpha 2-adrenergic agonists inhibit insulin secretion is by inhibiting Ca2+ influx through VDCC, an action that is mediated through a pertussis toxin-sensitive G-protein.
Intersubband laser coupled three-level asymmetric quantum wells: new dynamics of quantum interference

The improved density-functional theory is employed to obtain the eigenstates of electrons in an asymmetric quantum well. On the basis of calculated eigenstates, the semiconductor Bloch equations are used to calculate the transient density matrix when a pulsed intersubband laser coupling is applied to the system. The new dynamics of the individual absorption peaks is analyzed for the first time by use of a self-consistent-field theory. Based on this, the time-averaged optical spectrum is calculated to show the coherent-transition-induced quantum interference in the system. The new phenomena of probe-field amplification is observed, and the threshold laser intensity for observing it is given.
605. Long-Term Protection Afforded by a Single Administration of an Ad-Based Anti-Y. pestis Vaccine Against a Lethal Respiratory Challenge with Y. pestis

The aerosol form of the bacterium Yersinia pestis causes the pneumonic plague, a virulent and rapidly fatal disease that develops within days post-infection. In the context of a bioterror threat, an ideal anti-plague vaccine should elicit rapid, robust and long-acting protective immunity after a single dose. At present, no plague vaccines are available for use in the USA. One candidate for developing a subunit vaccine is the Yersinia pestis V antigen, a protein that influences the function of the Yersinia outer membrane proteins (Yops) virulence factors and has local anti-inflammatory effects in the host. Although protective immunity against Y. pestis challenge can be induced with recombinant V antigen, this immunization regimen requires multiple administrations and recent evidence suggests that long-term protection against Y. pestis requires strong cellular immune responses that are not stimulated by protein-based vaccines. Based on the knowledge that adenovirus (Ad)-based vaccine platforms rapidly induce humoral and cellular immune responses against expressed transgenes, we tested the hypothesis that a single administration of a replication-defective Ad gene transfer vector encoding the Y. pestis V antigen (AdsecV) could stimulate long-lasting protective immune responses, including cellular immune responses, without a requirement for repeat vaccine administration. To test the efficacy of the vaccine, mice immunized with a single administration of 1011 pu AdsecV were challenged intranasally 4 wk or 6 months after vaccination with doses of Y. pestis CO92 up to 106 cfu. At four wk post-administration, control mice that received saline (naive) or 1011 pu AdNull, a control vector, died within 3 to 5 days after challenge. In contrast, 100% of AdsecV-immunized mice (10/ 10) survived the intranasal challenge with 104 cfu and 8/10 and 9/10 of mice survived after infection with 105 and 106 cfu Y. pestis CO92, respectively (p<0.0001 for all doses). When mice immunized with a single dose of AdsecV were challenged 6 months post-administration, 100% of animals (10/10) survived intranasal infection with 104 cfu and 9/10 survived intranasal infection with 106 cfu Y. pestis CO92 (p<0.0001 for each dose). None of the control animals (naive or immunized with 1011 pu AdNull) survived the challenge. Protection was correlated with high anti-V antibody titers and, importantly, V- specific T cell responses (measured by ELISPOT). Consistent with the concept that cellular immune responses were relevant to protection, immunization of CD8+ T cell deficient mice (Cd8atm1Mak) with AdsecV did not protect any mice (0/10) from an intranasal infection with Y. pestis CO92 4 wk after immunization. These data suggest that AdsecV is a promising candidate as an effective single dose vaccine against the plague and that the cellular immune responses evoked by the vaccine play an important role in protection against respiratory infection with Y. pestis.
Intraarterial ethanol as a long-term occlusive agent in renal, hepatic, and gastrosplenic arteries of pigs

The renal, hepatic, or gastrosplenic arteries of eleven juvenile pigs were selectively injected intraarterially with 95% ethanol to evaluate its efficacy as an agent for use in permanent occlusion and infarction of the vascular bed supplied by the injected artery. A dose of 2.2 cc/5 kg (1 cc/5 lb) of 95% ethanol was injected over 30-45 sec. The animals were then killed at 1 to 91 days and all pigs demonstrated tissue infarction and vascular occlusion. Our results confirm that ethanol is an effective agent for the infarction of organs and that complications can result if catheter placement is not precise and normal tissue is inadvertently perfused.
Bladder papilloma: Therapeutic and cost effect of outpatient department management

Management of patients with benign papilloma of the bladder was reviewed for the calendar year 1979. Thirty-six patients (average age sixty-six years) were cystoscoped 113 times with 77 fulgurations. Over-all follow-up of these 36 patients averaged 8.2 years with a range of one to thirty-five years. In 5 patients (13.4 per cent) progressive disease developed: 1 invasive tumor requiring cystectomy, 2 Stage A lesions treated by transurethral resection, and 2 bilateral ureteral and renal pelvic papillomatosis with local bladder control. The average outpatient department (OPD) cost per patient in 1979 for management was $322.80 and for inpatient management $1,785.25. The over-all cost savings for 1979 was $112,608.65 among the patients treated for recurrence on an OPD basis. Outpatient management of benign bladder papilloma is a well-tolerated, therapeutically cost effective measure and is recommended.
Mobilization of cholesterol from cholesterol ester-enriched tissue culture cells by phospholipid dispersions

The accumulation of cholesterol esters in foam cells of the arterial intima is an important characteristic of fatty streak lesions of atherosclerosis. We wished to know if cholesterol ester accumulations in cells could be mobilized by altering their external milieu. Thus, phospholipid dispersions were used to remove cholesterol from a cholesterol ester-enriched cell line. Rat hepatoma cells, Fu5AH, were loaded with cholesterol esters by incubation in medium supplemented with hyperlipemic rabbit serum. After removing the loading medium, we incubated the cells in serum-free medium containing egg phosphatidylcholine dispersions. Unesterified cellular cholesterol level decreased in the first 4 h and then remained at a constant level. The cholesterol esters decreased after a lag time of about 2 h and the triacylglycerol level increased after 3 h. The decrease in cellular cholesterol ester depended on the amount of phospholipid in the medium. Cellular cholesterol ester decreased with increasing concentration of medium phospholipid to 2 mumols/ml and then plateaued. The removed cellular sterols appeared in the medium as free cholesterol. Since there was no measurable cholesterol esterase activity in the medium, the cholesterol ester in the cells was hydrolyzed before it appeared in the medium. The fatty acyl composition of the cellular cholesterol esters remained unchanged after significant reduction, suggesting that the hydrolysis of cholesterol esters was not specific for the acyl chain. Sphingomyelin and dimyristoyl phosphatidylcholine dispersions, though cytotoxic, were also effective in reducing cellular cholesterol esters. These experiments demonstrate that cholesterol ester accumulations in these cells can be reduced when phospholipid dispersions are used as cholesterol acceptors in the extracellular medium.
De-correlation technique for separation of drude parameters from wavelength modulation spectroscopy data

Separation of bound- and free-electron contributionsto the dielectric function is necessary for an accurate analysis of interband transitions. A technique for doing this separation which does not require low energy data is presented. The technique makes use of the fact that the functions which describe the contributions of each part are sufficiently uncorrelated, allowing the construction of a correlation function which uses the Drude effective mass and Drude relaxation time as adjustable parameters. The technique is shown to properly separate a test function and to yield reasonable results from experimental data. Une analyse rigoureuse des transitions entre bandes necessite une separation entre les contributions des electrons libres et celles des electrons lies. Nous presentons ici une technique pour effectuer une telle separation qui n'exige pas de donnees a basse energie. La technique en question utilise le fait que les fonctions decrivant les deux types de contributions sont suffisemment non correlees. Cela permet de construire une fonction de correlation en faisant de la masse effective de Drude et du temps de relaxation de Drude des parametres ajustables. Nous montions que cette technique separe proprement une fonction test et fournit des resultats raisonnables a partir de donnees experimentales.